Ground-nesting marine birds and potential for human disturbance in Glacier Bay National Park

USGS Publications Warehouse

Arimitsu, Mayumi L.; Romano, Marc D.; Piatt, John F.; Piatt, John F.; Gende, S.M.

2004-01-01

Glacier Bay National Park and Preserve contains a diverse assemblage of marine birds that use the area for nesting, foraging and molting. The abundance and diversity of marine bird species in Glacier Bay is unmatched in the region, due in part to the geomorphic and successional characteristics that result in a wide array of habitat types (Robards and others, 2003). The opportunity for proactive management of these species is unique in Glacier Bay National Park because much of the suitable marine bird nesting habitat occurs in areas designated as wilderness. Ground-nesting marine birds are vulnerable to human disturbance wherever visitors can access nest sites during the breeding season. Human disturbance of nest sites can be significant because intense parental care is required for egg and hatchling survival, and repeated disturbance can result in reduced productivity (Leseberg and others, 2000). Temporary nest desertion by breeding birds in disturbed areas can lead to increased predation on eggs and hatchlings by conspecifics or other predators (Bolduc and Guillemette, 2003). Human disturbance of ground-nesting birds may also affect incubation time and adult foraging success, which in turn can alter breeding success (Verhulst and others, 2001). Furthermore, human activity can potentially cause colony failure when disturbance prevents the initiation of nesting (Hatch, 2002). There is management concern about the susceptibility of breeding birds to disturbance from human activities, but little historical data has been collected on the distribution of ground-nesting marine birds in Glacier Bay. This report summarizes results obtained during two years of a three-year study to determine the distribution of ground-nesting marine birds in Glacier Bay, and the potential for human disturbance of those nesting birds.

Nest site preferences of the Woodlark (Lullula arborea) and its association with artificial nest predation

NASA Astrophysics Data System (ADS)

Buehler, Roman; Bosco, Laura; Arlettaz, Raphaël; Jacot, Alain

2017-01-01

The Woodlark is an insectivorous bird, which is listed as a priority species in Switzerland. In Valais, a stronghold of this species in the country, the birds breed in intensively managed vineyards and show a preference for parcels with ground vegetation during territory establishment. As a ground-breeder, the species is highly vulnerable to nest predation by avian and mammal predators. The aims of our study were firstly to investigate nest site preferences of the woodlark within vineyards and secondly to compare the predation risk of artificial nests dependent of ground vegetation structure. Our results point out that the Woodlark prefers patches of tall and dense ground cover within vegetated vineyard parcels and avoids parcels that have been treated with herbicides. In a follow-up experiment we conducted a study comparing the predation rate of artificial nests between bare parcels (<20% vegetated area) and vegetated parcels (>40% vegetated area). Artificial nests equipped with one quail egg were distributed pairwise between two adjacent parcels that fulfilled the upper criteria and were monitored by trail cameras during 10-12 days. Predation rate was generally low (4 predation events) and only occurred in bare parcels. These data indicate that conspicuousness of avian nests may be decreased in vegetated parcels and that the amount of vegetation can lower the predation risk on ground breeding birds - another indication for the importance of ground vegetation for a successful conservation of the endangered Woodlark in Swiss vineyards.

Linking snake habitat use to nest predation risk in grassland birds: the dangers of shrub cover.

PubMed

Klug, Page E; Jackrel, Sara L; With, Kimberly A

2010-03-01

Extremes in rangeland management, varying from too-frequent fire and intensive grazing to the suppression of both, threaten rangeland ecosystems worldwide. Intensive fire and grazing denude and homogenize vegetation whereas their suppression increases woody cover. Although habitat loss is implicated in grassland bird declines, degradation through intensive management or neglect also decreases breeding habitat and may reduce nesting success through increased rates of nest predation. Snakes are important nest predators, but little is known about how habitat use in snakes relates to predation risk for grassland birds nesting within tallgrass prairie subjected to different grazing and fire frequencies. We evaluated nest survival in the context of habitat used by nesting songbirds and two bird-eating snakes, the eastern yellowbelly racer Coluber constrictor flaviventris and Great Plains ratsnake Pantherophis emoryi. Daily nest survival rates decreased with increasing shrub cover and decreasing vegetation height, which characterize grasslands that have been neglected or intensively managed, respectively. Discriminant function analysis revealed that snake habitats were characterized by higher shrub cover, whereas successful nests were more likely to occur in areas with tall grass and forbs but reduced shrub cover. Because snakes often use shrub habitat, birds nesting in areas with increased shrub cover may be at higher risk of nest predation by snakes in addition to other predators known to use shrub habitat (e.g., mid-sized carnivores and avian predators). Depredated nests also occurred outside the discriminant space of the snakes, indicating that other predators (e.g., ground squirrels Spermophilus spp. and bullsnakes Pituophis catenifer) may be important in areas with denuded cover. Targeted removal of shrubs may increase nest success by minimizing the activity of nest predators attracted to shrub cover.

Landscape-moderated bird nest predation in hedges and forest edges

NASA Astrophysics Data System (ADS)

Ludwig, Martin; Schlinkert, Hella; Holzschuh, Andrea; Fischer, Christina; Scherber, Christoph; Trnka, Alfréd; Tscharntke, Teja; Batáry, Péter

2012-11-01

Landscape-scale agricultural intensification has caused severe declines in biodiversity. Hedges and forest remnants may mitigate biodiversity loss by enhancing landscape heterogeneity and providing habitat to a wide range of species, including birds. However, nest predation, the major cause of reproductive failure of birds, has been shown to be higher in forest edges than in forest interiors. Little is known about how spatial arrangement (configuration) of hedges affects the avian nest predation. We performed an experiment with artificial ground and elevated nests (resembling yellowhammer and whitethroat nests) baited with quail and plasticine eggs. Nests were placed in three habitat types with different degrees of isolation from forests: forest edges, hedges connected to forests and hedges isolated from forests. Nest predation was highest in forest edges, lowest in hedges connected to forests and intermediate in isolated hedges. In the early breeding season, we found similar nest predation on ground and elevated nests, but in the late breeding season nest predation was higher on ground nests than on elevated nests. Small mammals were the main predators of ground nests and appeared to be responsible for the increase in predation from early to late breeding season, whereas the elevated nests were mainly depredated by small birds and small mammals. High predation pressure at forest edges was probably caused by both forest and open-landscape predators. The influence of forest predators may be lower at hedges, leading to lower predation pressure than in forest edges. Higher predation pressure in isolated than connected hedges might be an effect of concentration of predators in these isolated habitats. We conclude that landscape configuration of hedges is important in nest predation, with connected hedges allowing higher survival than isolated hedges and forest edges.

Conservation implications when the nest predators are known

USGS Publications Warehouse

Ribic, Christine; Thompson, Frank

2012-01-01

Conservation and management of passerines has largely focused on habitat manipulation or restoration because the natural communities on which these birds depend have been destroyed and fragmented. However, productivity is another important aspect of avian conservation, and nest predation can be a large source of nesting mortality for passerines. Recent studies using video surveillance to identify nest predators allow researchers to start evaluating what methods could be used to mitigate nest predation to help passerines of conservation concern. From recent studies, we identified latitudinal and habitat-related patterns in the importance of predator groups that depredate passerine nests. We then reviewed how knowledge of specific nest predators can benefit conservation of bird species of concern. Mammals were the dominant predator group in northern grasslands. Snakes were the dominant predator group in southern habitats. Fire ants were only a nest predator in southern latitudes. Differences in the importance of predator species or groups were likely the result of both their geographic patterns of distribution and habitat preferences. Some direct and indirect predator control measures developed for waterfowl management potentially could be used to benefit passerine productivity. We reviewed three examples-cowbirds, snakes in shrublands, and ground squirrels in grasslands-to illustrate how different predator control strategies may be needed in different situations. Mitigation of passerine nest predation will need to be based on knowledge of predator communities to be effective. This requires large samples of predation events with identified predators; video technology is essential for this task.

Bird productivity and nest predation in agricultural grasslands

USGS Publications Warehouse

Ribic, Christine; Guzy, Michael J.; Anderson, Travis J.; Sample, David W.; Nack, Jamie L.

2012-01-01

Effective conservation strategies for grassland birds in agricultural landscapes require understanding how nesting success varies among different grassland habitats. A key component to this is identifying nest predators and how these predators vary by habitat. We quantified nesting activity of obligate grassland birds in three habitats [remnant prairie, cool-season grass Conservation Reserve Program (CRP) fields, and pastures) in southwest Wisconsin, 2002-2004. We determined nest predators using video cameras and examined predator activity using track stations. Bobolink (Dolichonyx oryzivorus) and Henslow's Sparrow (Ammodramus henslowii) nested primarily in CRP fields, and Grasshopper Sparrow (A. savannarum) in remnant prairies. Eastern Meadowlark (Sturnella magna) nested evenly across all three habitats. Daily nest survival rate for Eastern Meadowlark varied by nesting stage alone. Daily nest survival rate for Grasshopper Sparrow varied by nest vegetation and distance to the nearest woody edge; nest survival was higher near woody edges. In CRP fields, most predators were grassland-associated, primarily thirteen-lined ground squirrels (Ictidomys tridecemlineatus). In pastures, one-third of the nest predators were grassland-associated (primarily thirteen-lined ground squirrels) and 56% were associated with woody habitats (primarily raccoons, Procyon lotor). Raccoon activity was greatest around pastures and lowest around prairies; regardless of habitat, raccoon activity along woody edges was twice that along non-woody edges. Thirteen-lined ground squirrel activity was greater along prairie edges than pastures and was greater along nonwoody edges compared to woody edges. In CRP fields, raccoon activity was greater along edges compared to the interiors; for ground squirrels these relationships were reversed. Using video camera technology to identify nest predators was indispensable in furthering our understanding of the grassland system. The challenge is to use that knowledge to develop management actions for both birds and predators.

Predation risk of artificial ground nests in managed floodplain meadows

NASA Astrophysics Data System (ADS)

Arbeiter, Susanne; Franke, Elisabeth

2018-01-01

Nest predation highly determines the reproductive success in birds. In agricultural grasslands, vegetation characteristics and management practices influences the predation risk of ground breeders. Little is known so far on the predation pressure on non-passerine nests in tall swards. Investigations on the interaction of land use with nesting site conditions and the habitat selection of nest predators are crucial to develop effective conservation measures for grassland birds. In this study, we used artificial nests baited with quail and plasticine eggs to identify potential predators of ground nests in floodplain meadows and related predation risk to vegetation structure and grassland management. Mean daily predation rate was 0.01 (±0.012) after an exposure duration of 21 days. 70% of all observed nest predations were caused by mammals (Red Fox and mustelids) and 17.5% by avian predators (corvids). Nest sites close to the meadow edge and those providing low forb cover were faced with a higher daily predation risk. Predation risk also increased later in the season. Land use in the preceding year had a significant effect on predation risk, showing higher predation rates on unmanaged sites than on mown sites. Unused meadows probably attract mammalian predators, because they provide a high abundance of small rodents and a more favourable vegetation structure for foraging, increasing also the risk of incidental nest predations. Although mowing operation is a major threat to ground-nesting birds, our results suggest that an annual removal of vegetation may reduce predation risk in the subsequent year.

Mercury and selenium concentrations in leatherback sea turtles (Dermochelys coriacea): population comparisons, implications for reproductive success, hazard quotients and directions for future research.

PubMed

Perrault, Justin R; Miller, Debra L; Garner, Jeanne; Wyneken, Jeanette

2013-10-01

Leatherback sea turtles (Dermochelys coriacea) are long-distance migrants that travel thousands of km from foraging grounds to breeding and nesting grounds. These extensive journeys are fueled by ingestion of an estimated 300-400 kg of prey/d and likely result in exposure to high concentrations of environmental toxicants (e.g., mercury compounds). Increased bodily concentrations of mercury and its compounds in nesting female turtles may have detrimental effects on reproductive success. Leatherbacks have relatively low reproductive success compared with other sea turtles (global average hatching success ~50-60%). To assess toxicants and necessary nutrients as factors affecting leatherback turtle reproductive success at Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands, we collected blood from nesting female leatherbacks and tissues from their hatchlings (blood from live turtles, liver and yolk sac from dead turtles). We compared the concentrations in those tissues to hatching and emergence success. We found that on SPNWR, hatching and emergence success were more closely related to seasonal factors than to total mercury and selenium concentrations in both nesting females and hatchlings. Selenium concentrations of nesting females were positively correlated with those of their hatchlings. Mercury and selenium in the liver of hatchlings were positively correlated with one another. Turtles with greater remigration intervals tended to have higher blood selenium concentrations, suggesting that selenium accumulates in leatherbacks through time. Through hazard quotients, we found evidence that selenium may be at or above concentrations that may cause physiologic harm to hatchlings. We also found evidence that population level differences exist for these trace elements. The concentrations of mercury and selenium established in this manuscript form a baseline for future toxicant studies. Copyright © 2013 Elsevier B.V. All rights reserved.

Distribution of ground-nesting marine birds along shorelines in Glacier Bay, southeastern Alaska: An assessment related to potential disturbance by back-country users

USGS Publications Warehouse

Arimitsu, Mayumi L.; Piatt, John F.; Romano, Marc D.

2007-01-01

With the exception of a few large colonies, the distribution of ground-nesting marine birds in Glacier Bay National Park in southeastern Alaska is largely unknown. As visitor use increases in back-country areas of the park, there is growing concern over the potential impact of human activities on breeding birds. During the 2003–05 breeding seasons, the shoreline of Glacier Bay was surveyed to locate ground-nesting marine birds and their nesting areas, including wildlife closures and historical sites for egg collection by Alaska Native peoples. The nesting distribution of four common ground-nesting marine bird species was determined: Arctic Tern (Sterna paradisaea), Black Oystercatcher (Haematopus bachmani), Mew Gull (Larus canus), and Glaucous-winged Gull (Larus glaucescens). Observations of less abundant species also were recorded, including Herring Gull (Larus argentatus), Red-throated Loon (Gavia stellata), Canada Goose (Branta canadensis), Willow Ptarmigan (Lagopus lagopus), Semipalmated Plover (Charadrius semipalmatus), Spotted Sandpiper (Actitis macularia), Least Sandpiper (Calidris minutilla), Parasitic Jaeger (Stercorarius parasiticus), and Aleutian Tern (Sterna aleutica). Nesting distribution for Arctic Terns was largely restricted to the upper arms of the bay and a few treeless islets in the lower bay, whereas Black Oystercatchers were more widely distributed along shorelines in the park. Mew Gulls nested throughout the upper bay in Geikie Inlet and in Fingers and Berg Bays, and most Glaucous-winged Gull nests were found at wildlife closures in the central and lower bays. Several areas were identified where human disturbance could affect breeding birds. This study comprises the first bay-wide survey for the breeding distribution of ground-nesting marine birds in Glacier Bay National Park, providing a minimum estimate of their numbers and distribution within the park. This information can be used to assess future human disturbance and track natural changes in nesting bird distribution over time.

Nest site ecology of the Cross River gorilla at the Kagwene Gorilla Sanctuary, Cameroon, with special reference to anthropogenic influence.

PubMed

De Vere, Ruth A; Warren, Ymke; Nicholas, Aaron; Mackenzie, Mary E; Higham, James P

2011-03-01

The Cross River gorilla is the most endangered of all Great Apes. It is currently found in 14 apparently geographically separate and increasingly isolated populations, which face severe threats from habitat loss and the bushmeat trade. Recent years have seen greater efforts to conserve the Cross River gorilla across the landscape, but details of the ecology of individual populations that might help in conservation initiatives are lacking. Here, we report on the production of the first habitat map for the recently created Kagwene Gorilla Sanctuary (KGS), Cameroon, and the results of an analysis of nest site preferences of the gorillas that live there. Qualitative vegetation assessments were made to assign various categories to the topstory and understory throughout the sanctuary, and nest sites constructed between January 2006 and March 2008 were re-visited and assessed for possible site preferences. The habitat map revealed significant anthropogenic impact, with only 57% of the KGS being relatively undisturbed primary forest. Analysis of nest sites showed that ground nests are constructed preferentially in the dry season, on precipitous slopes, in light gaps and clearings, with an understory of mixed herbs. Tree nests are predominantly built in the wet season, in primary forest with saplings as the preferred understory. Gorillas avoid nesting in grasslands and farms, which visibly fragment the remaining forest in the sanctuary. The results have implications for the conservation and management of the Cross River gorilla at KGS, and offer new insight into the nesting ecology of this subspecies. 2010 Wiley-Liss, Inc.

Nest and nest site characteristics of some ground-nesting, non-passerine birds of northern grasslands

USGS Publications Warehouse

Kantrud, Harold A.; Higgins, Kenneth F.

1992-01-01

We summarized biological and ecologic characteristics of 2490 nests of 16 species of upland-nesting, non-passerine birds of northern grasslands found during 1963 through 1991. Nest initiation and hatch dates, clutch sizes, nest fates, causes of failure, success rates of nests among major habitat types and land uses, and vegetation measurements at nest sites are analyzed.

Status and nesting of Ferruginous Hawks (Buteo regalis) in Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitzner, R.E.; Boyd, L.L.; Berry, D.

1975-01-01

Nesting of ferruginous hawks in Washington is confined to the shrubsteppe region in the eastern part of the state. The birds nest in two entirely different situations, either on outcroppings of basalt on the slopes of hillsides and canyons, or on the canopy of Juniper trees. Nests dimensions and materials are described. A nearly complete survey of all available nesting habitat in the state revealed that no fewer than 15 and perhaps 20 pair of adult birds breed in the state. Of these, we expect that 12 or 13 pairs will produce young each year. Dietary analysis revealed that smallmore » mammals (pocket gophers and ground squirrels) were the most frequently consumed prey items. Small birds, primarily meadowlarks, were frequently consumed prey by both ground and tree nesters. Insects and lagomorphs were fairly abundant as prey items at a ground nest, while snakes (yellow-bellied racer and bullsnake) seemed to replace them in importance at a Juniper nesting site. Dark phase ferruginous hawks are reported for the first time in Washington State.« less

Comparative nest-site habitat of painted redstarts and red-faced warblers in the Madrean Sky Islands of southeastern Arizona

Treesearch

Joseph L. Ganey; William M. Block; Jamie S. Sanderlin; Jose M. Iniguez

2015-01-01

Conservation of avian species requires understanding their nesting habitat requirements. We compared 3 aspects of habitat at nest sites (topographic characteristics of nest sites, nest placement within nest sites, and canopy stratification within nest sites) of 2 related species of ground-nesting warblers (Red-faced Warblers, Cardellina rubrifrons, n = 17...

Nest Construction by a Ground-nesting Bird Represents a Potential Trade-off Between Egg Crypticity and Thermoregulation

EPA Science Inventory

Predation selects against conspicuous colors in bird eggs and nests, while thermoregulatory constraints select for nest building behavior that regulates incubation temperatures. We present results that reveal a trade-off between nest crypticity and thermoregulation of eggs base...

Behavior of radio-marked breeding American woodcocks

USGS Publications Warehouse

McAuley, D.G.; Longcore, J.R.; Sepik, G.F.; Longcore, Jerry R.; Sepik, Greg F.

1993-01-01

During spring 1986-89, we equipped 175 male and 89 female American woodcocks (Scolopax minor) with radio transmitters. Radio-marking had little effect on behavior; within 1 day of marking, 37 of 64 (58%) displaying males were dominant and within 7 days, 138 of 157 (88%) were dominant. All females marked before nesting proceeded to nest, and marked females with broods remained with broods after release. Dominance of males declined from 73% in April to 69% in May and to 26% in June as breeding activity waned. In all years, after-second-year (ASY) males were dominant more often than second-year (SY) males (67.5% vs. 58.9%). ;Most males displayed at more than one (range = 2-12) site. Distances that males moved between the primary singing ground and subsequent singing grounds averaged 775 m in all years and ranged from 618 m (1986) to 966 m (1988). Females visited males at singing grounds throughout the breeding cycle; some females visited more than one site. During prenesting, females remained in daytime covers during the crepuscular period (55%), flew to different feeding covers (22%), visited singing grounds (14%), or flew from daytime covers to unknown locations (9%). During nesting, females left nests during the crepuscular period (72%) and moved to singing grounds (5%), to feeding areas (59%), and to undetermined locations (7%). Females with broods remained with their broods during the crepuscular period (62%), flew to feeding areas (30%), visited singing grounds (1%), or flew to undetermined locations (6%). The woodcock mating system is similar to a resource-based polygyny. Males compete for singing grounds near high-quality nesting areas. The fitness of males is expressed by dominance at more than one singing ground. Woodcocks are not monogamous; females may visit more than three different males during a single courtship period but do not visit males regularly. Most females leave nests during the crepuscular period to feed in a different cover.

Fire and shade effects on ground cover structure in Kirtland's warbler habitat

Treesearch

John R. Probst; Deahn DonnerWright

2003-01-01

Researchers and managers have suggested that a narrow range of ground-cover structure resulting from fire might be necessary for suitable Kirtland`s warbler nesting conditions. Yet, Kirtland`s warblers have bred successfully in numerous unburned stands and there is little direct evidence to indicate that ground cover structure is a limiting factor for nest sites or...

The possible function of stone ramparts at the nest entrance of the blackstart.

PubMed

Leader; Yom-tov

1998-07-01

Blackstarts, Cercomela melanura, Turdidae, construct a rampart of stones at the entrance to their nests. These ramparts may reach remarkable proportions, containing hundreds of flat rocks. We investigated several hypotheses regarding the function of stone ramparts, by monitoring individually marked blackstarts at the En-Gedi Nature Reserve, Israel. Stones were collected solely by females, who carried them in their beaks, while flying to the nest, at a rate of up to one stone per min, after pair formation had occurred. The number and total weight of stones as well as rampart height showed a highly positive correlation with the size of the nest cavity opening. The rampart decreased the size of the cavity entrance to some nests by as much as 67%, which suggests an antipredator barrier function. Survival rates of eggs and chicks were extremely low and the major cause of reproductive failure was predation. Successful nests tended to be located higher off the ground than predated nests, and often contained fewer stones. Furthermore, larger females in terms of wing and tail length nested in cavities higher off the ground and built smaller ramparts containing lighter stones. An artificial nest predation experiment did not reveal a difference in predation rates between nests with and without stone ramparts. Spiny mice, Acomys sp., were the main egg predators. However, in 37% of nests with ramparts that were predated, the perpetrator flattened the rampart, suggesting that they may serve as a barricade, forcing the predator to invest time in clearing the stones in order to gain access to the nest, and perhaps allowing the nesting female sufficient time to escape. We propose, therefore, that owing to such high nest predation rates, females nesting close to the ground build stone ramparts as an 'early warning' mechanism to prevent themselves from being trapped inside nest cavities and predated. Copyright 1998 The Association for the Study of Animal Behaviour.

The View from the Trees: Nocturnal Bull Ants, Myrmecia midas, Use the Surrounding Panorama While Descending from Trees

PubMed Central

Freas, Cody A.; Wystrach, Antione; Narendra, Ajay; Cheng, Ken

2018-01-01

Solitary foraging ants commonly use visual cues from their environment for navigation. Foragers are known to store visual scenes from the surrounding panorama for later guidance to known resources and to return successfully back to the nest. Several ant species travel not only on the ground, but also climb trees to locate resources. The navigational information that guides animals back home during their descent, while their body is perpendicular to the ground, is largely unknown. Here, we investigate in a nocturnal ant, Myrmecia midas, whether foragers travelling down a tree use visual information to return home. These ants establish nests at the base of a tree on which they forage and in addition, they also forage on nearby trees. We collected foragers and placed them on the trunk of the nest tree or a foraging tree in multiple compass directions. Regardless of the displacement location, upon release ants immediately moved to the side of the trunk facing the nest during their descent. When ants were released on non-foraging trees near the nest, displaced foragers again travelled around the tree to the side facing the nest. All the displaced foragers reached the correct side of the tree well before reaching the ground. However, when the terrestrial cues around the tree were blocked, foragers were unable to orient correctly, suggesting that the surrounding panorama is critical to successful orientation on the tree. Through analysis of panoramic pictures, we show that views acquired at the base of the foraging tree nest can provide reliable nest-ward orientation up to 1.75 m above the ground. We discuss, how animals descending from trees compare their current scene to a memorised scene and report on the similarities in visually guided behaviour while navigating on the ground and descending from trees. PMID:29422880

The View from the Trees: Nocturnal Bull Ants, Myrmecia midas, Use the Surrounding Panorama While Descending from Trees.

PubMed

Freas, Cody A; Wystrach, Antione; Narendra, Ajay; Cheng, Ken

2018-01-01

Solitary foraging ants commonly use visual cues from their environment for navigation. Foragers are known to store visual scenes from the surrounding panorama for later guidance to known resources and to return successfully back to the nest. Several ant species travel not only on the ground, but also climb trees to locate resources. The navigational information that guides animals back home during their descent, while their body is perpendicular to the ground, is largely unknown. Here, we investigate in a nocturnal ant, Myrmecia midas , whether foragers travelling down a tree use visual information to return home. These ants establish nests at the base of a tree on which they forage and in addition, they also forage on nearby trees. We collected foragers and placed them on the trunk of the nest tree or a foraging tree in multiple compass directions. Regardless of the displacement location, upon release ants immediately moved to the side of the trunk facing the nest during their descent. When ants were released on non-foraging trees near the nest, displaced foragers again travelled around the tree to the side facing the nest. All the displaced foragers reached the correct side of the tree well before reaching the ground. However, when the terrestrial cues around the tree were blocked, foragers were unable to orient correctly, suggesting that the surrounding panorama is critical to successful orientation on the tree. Through analysis of panoramic pictures, we show that views acquired at the base of the foraging tree nest can provide reliable nest-ward orientation up to 1.75 m above the ground. We discuss, how animals descending from trees compare their current scene to a memorised scene and report on the similarities in visually guided behaviour while navigating on the ground and descending from trees.

Inadequate thermal refuge constrains landscape habitability for a grassland bird species

PubMed Central

Pierce, Brian L.

2017-01-01

Ecologists have long recognized the influence that environmental conditions have on abundance and range extent of animal species. We used the northern bobwhite (Colinus virginianus; hereafter bobwhite) as a model species for studying how microclimates serve as refuge against severe weather conditions. This species serves as an indicator or umbrella species for other sensitive ground-nesting, grassland obligate species. We conducted a mensurative field experiment in the rolling plains of Texas, USA, a semi-arid ecosystem on the southwestern periphery of bobwhite range, to determine whether native bunch grasses, apparently suitable for bobwhite nesting, could reduce ambient temperature below levels harmful for eggs. During the nesting season, we compared temperature and relative humidity readings at daily heat maxima (i.e., the 3 h during each day with highest temperatures) during the nesting season over the course of two years at 63 suitable nest sites paired with 63 random locations (n = 126) using two sensors at ∼10 and ∼60 cm above ground level. Mean temperature at nest height was 2.3% cooler at nest sites (35.99 °C ± 0.07 SE) compared to random locations (36.81 °C ± 0.07 SE); at ambient height, nest sites were slightly cooler (32.78 °C ± 0.06 SE) than random location (32.99 °C ± 0.06 SE). Mean relative humidity at nest sites was greater at nest height (34.53% ± 0.112 SE) and ambient height (36.22% ± 0.10 SE) compared to random locations at nest (33.35% ± 0.12 SE) and ambient height (35.75% ± 0.10 SE). Based on these results, cover at sites that appear visually suitable for nesting by bobwhites and other ground nesting birds provided adequate thermal refuge in the rolling plains by maintaining cooler, moister microclimates than surrounding non-nesting locations. Post-hoc analyses of data revealed that habitat conditions surrounding suitable nest sites strongly influenced thermal suitability of the substrate. Given that eggs of bobwhites and probably other species would experience lethal temperatures without these thermal refuges in the context of proper habitat condition, nesting vegetation is a critical component of niche space for bobwhites and other ground nesting birds in semi-arid regions. Many contemporary land uses, however, degrade or destroy bunch grasses and grassland systems, and thus decrease landscape inhabitability. Conservationists working with obligate grassland species that require bunch grasses in semi-arid regions should develop land management strategies that maximize the availability of these thermal refuges across space and time. PMID:28828282

Inadequate thermal refuge constrains landscape habitability for a grassland bird species.

PubMed

Tomecek, John M; Pierce, Brian L; Reyna, Kelly S; Peterson, Markus J

2017-01-01

Ecologists have long recognized the influence that environmental conditions have on abundance and range extent of animal species. We used the northern bobwhite ( Colinus virginianus ; hereafter bobwhite) as a model species for studying how microclimates serve as refuge against severe weather conditions. This species serves as an indicator or umbrella species for other sensitive ground-nesting, grassland obligate species. We conducted a mensurative field experiment in the rolling plains of Texas, USA, a semi-arid ecosystem on the southwestern periphery of bobwhite range, to determine whether native bunch grasses, apparently suitable for bobwhite nesting, could reduce ambient temperature below levels harmful for eggs. During the nesting season, we compared temperature and relative humidity readings at daily heat maxima (i.e., the 3 h during each day with highest temperatures) during the nesting season over the course of two years at 63 suitable nest sites paired with 63 random locations ( n = 126) using two sensors at ∼10 and ∼60 cm above ground level. Mean temperature at nest height was 2.3% cooler at nest sites (35.99 °C ± 0.07 SE) compared to random locations (36.81 °C ± 0.07 SE); at ambient height, nest sites were slightly cooler (32.78 °C ± 0.06 SE) than random location (32.99 °C ± 0.06 SE). Mean relative humidity at nest sites was greater at nest height (34.53% ± 0.112 SE) and ambient height (36.22% ± 0.10 SE) compared to random locations at nest (33.35% ± 0.12 SE) and ambient height (35.75% ± 0.10 SE). Based on these results, cover at sites that appear visually suitable for nesting by bobwhites and other ground nesting birds provided adequate thermal refuge in the rolling plains by maintaining cooler, moister microclimates than surrounding non-nesting locations. Post-hoc analyses of data revealed that habitat conditions surrounding suitable nest sites strongly influenced thermal suitability of the substrate. Given that eggs of bobwhites and probably other species would experience lethal temperatures without these thermal refuges in the context of proper habitat condition, nesting vegetation is a critical component of niche space for bobwhites and other ground nesting birds in semi-arid regions. Many contemporary land uses, however, degrade or destroy bunch grasses and grassland systems, and thus decrease landscape inhabitability. Conservationists working with obligate grassland species that require bunch grasses in semi-arid regions should develop land management strategies that maximize the availability of these thermal refuges across space and time.

Use of no-till winter wheat by nesting ducks in North Dakota

USGS Publications Warehouse

Duebbert, H.F.; Kantrud, H.A.

1987-01-01

Nesting of dabbling ducks (Anatinae) was studied in fields of no-till winter wheat (Triticum aestivum) in the prairie pothole region of North Dakota during 1984 and 1985. Total area of 59 fields searched in 1984 was 1,135 ha and total area of 70 fields searched in 1985 was 1,175 ha. Field sizes ranged from 3 ha to 110 ha. Nests of five duck species were found: blue-winged teal (Anas discors), 55 nests; northern pintail (A. acuta), 44; mallard (A. platyrhynchos), 29; gadwall (A. strepera), 15; and northern shoveler (A. clypeata), 8. The average number of nests found was 8/100 ha in 1984 and 6/100 ha in 1985. Nest success for all species averaged 26% in 1984 and 29% in 1985. Predation by mammals was the principal cause of nest destruction. No egg or hen mortality could be attributed to pesticide use. Only 6 of 151 nests (4%) were abandoned during the two years. We also found 29 nests of seven other ground-nesting bird species. The trend toward increased planting of no-till winter wheat in the prairie pothole region should benefit production of ducks and other ground-nesting birds.

Contextualising the Last Survivors: Population Structure of Marine Turtles in the Dominican Republic.

PubMed

Carreras, Carlos; Godley, Brendan J; León, Yolanda M; Hawkes, Lucy A; Revuelta, Ohiana; Raga, Juan A; Tomás, Jesús

2013-01-01

Nesting by three species of marine turtles persists in the Dominican Republic, despite historic threats and long-term population decline. We conducted a genetic survey of marine turtles in the Dominican Republic in order to link them with other rookeries around the Caribbean. We sequenced a 740bp fragment of the control region of the mitochondrial DNA of 92 samples from three marine turtle species [hawksbill (n = 48), green (n = 2) and leatherback (n = 42)], and incorporated published data from other nesting populations and foraging grounds. The leatherback turtle (Dermochelys coriacea) in the Dominican Republic appeared to be isolated from Awala-Yalimapo, Cayenne, Trinidad and St. Croix but connected with other Caribbean populations. Two distinct nesting populations of hawksbill turtles (Eremochelys imbricata) were detected in the Dominican Republic and exhibited interesting patterns of connectivity with other nesting sites and juvenile and adult male foraging aggregations. The green sea turtle (Chelonia mydas) has almost been extirpated from the Dominican Republic and limited inference could be made from our samples. Finally, results were compared with Lagrangian drifting buoys and published Lagrangian virtual particles that travelled through the Dominican Republic and Caribbean waters. Conservation implications of sink-source effects or genetic isolation derived from these complex inter-connections are discussed for each species and population.

Contextualising the Last Survivors: Population Structure of Marine Turtles in the Dominican Republic

PubMed Central

Carreras, Carlos; Godley, Brendan J.; León, Yolanda M.; Hawkes, Lucy A.; Revuelta, Ohiana; Raga, Juan A.; Tomás, Jesús

2013-01-01

Nesting by three species of marine turtles persists in the Dominican Republic, despite historic threats and long-term population decline. We conducted a genetic survey of marine turtles in the Dominican Republic in order to link them with other rookeries around the Caribbean. We sequenced a 740bp fragment of the control region of the mitochondrial DNA of 92 samples from three marine turtle species [hawksbill (n = 48), green (n = 2) and leatherback (n = 42)], and incorporated published data from other nesting populations and foraging grounds. The leatherback turtle (Dermochelys coriacea) in the Dominican Republic appeared to be isolated from Awala-Yalimapo, Cayenne, Trinidad and St. Croix but connected with other Caribbean populations. Two distinct nesting populations of hawksbill turtles (Eremochelys imbricata) were detected in the Dominican Republic and exhibited interesting patterns of connectivity with other nesting sites and juvenile and adult male foraging aggregations. The green sea turtle (Chelonia mydas) has almost been extirpated from the Dominican Republic and limited inference could be made from our samples. Finally, results were compared with Lagrangian drifting buoys and published Lagrangian virtual particles that travelled through the Dominican Republic and Caribbean waters. Conservation implications of sink-source effects or genetic isolation derived from these complex inter-connections are discussed for each species and population. PMID:23840394

Identifying predators and fates of grassland passerine nests using miniature video cameras

USGS Publications Warehouse

Pietz, Pamela J.; Granfors, Diane A.

2000-01-01

Nest fates, causes of nest failure, and identities of nest predators are difficult to determine for grassland passerines. We developed a miniature video-camera system for use in grasslands and deployed it at 69 nests of 10 passerine species in North Dakota during 1996-97. Abandonment rates were higher at nests 1 day or night (22-116 hr) at 6 nests, 5 of which were depredated by ground squirrels or mice. For nests without cameras, estimated predation rates were lower for ground nests than aboveground nests (P = 0.055), but did not differ between open and covered nests (P = 0.74). Open and covered nests differed, however, when predation risk (estimated by initial-predation rate) was examined separately for day and night using camera-monitored nests; the frequency of initial predations that occurred during the day was higher for open nests than covered nests (P = 0.015). Thus, vulnerability of some nest types may depend on the relative importance of nocturnal and diurnal predators. Predation risk increased with nestling age from 0 to 8 days (P = 0.07). Up to 15% of fates assigned to camera-monitored nests were wrong when based solely on evidence that would have been available from periodic nest visits. There was no evidence of disturbance at nearly half the depredated nests, including all 5 depredated by large mammals. Overlap in types of sign left by different predator species, and variability of sign within species, suggests that evidence at nests is unreliable for identifying predators of grassland passerines.

Impacts of short-rotation early-growing season prescribed fire on a ground nesting bird in the central hardwoods region of North America

USGS Publications Warehouse

Pittman, H. Tyler; Krementz, David G.

2016-01-01

Landscape-scale short-rotation early-growing season prescribed fire, hereafter prescribed fire, in upland hardwood forests represents a recent shift in management strategies across eastern upland forests. Not only does this strategy depart from dormant season to growing season prescriptions, but the strategy also moves from stand-scale to landscape-scale implementation (>1,000 ha). This being so, agencies are making considerable commitments in terms of time and resources to this management strategy, but the effects on wildlife in upland forests, especially those dominated by hardwood canopy species, are relatively unknown. We initiated our study to assess whether this management strategy affects eastern wild turkey reproductive ecology on the Ozark-St. Francis National Forest. We marked 67 wild turkey hens with Global Positioning System (GPS) Platform Transmitting Terminals in 2012 and 2013 to document exposure to prescribed fire, and estimate daily nest survival, nest success, and nest-site selection. We estimated these reproductive parameters in forest units managed with prescribed fire (treated) and units absent of prescribed fire (untreated). Of 60 initial nest attempts monitored, none were destroyed or exposed to prescribed fire because a majority of fires occurred early than a majority of the nesting activity. We found nest success was greater in untreated units than treated units (36.4% versus 14.6%). We did not find any habitat characteristic differences between successful and unsuccessful nest-sites. We found that nest-site selection criteria differed between treated and untreated units. Visual concealment and woody ground cover were common selection criteria in both treated and untreated units. However, in treated units wild turkey selected nest-sites with fewer small shrubs (<5 cm ground diameter) and large trees (>20 cm DBH) but not in untreated units. In untreated units wild turkey selected nest-sites with more large shrubs (≥5cm ground diameter) but did not select for small shrubs or large trees. Our findings suggest that wild turkey have not benefited from the reintroduction of prescribed fire to the WRERA.

Impacts of Short-Rotation Early-Growing Season Prescribed Fire on a Ground Nesting Bird in the Central Hardwoods Region of North America

PubMed Central

2016-01-01

Landscape-scale short-rotation early-growing season prescribed fire, hereafter prescribed fire, in upland hardwood forests represents a recent shift in management strategies across eastern upland forests. Not only does this strategy depart from dormant season to growing season prescriptions, but the strategy also moves from stand-scale to landscape-scale implementation (>1,000 ha). This being so, agencies are making considerable commitments in terms of time and resources to this management strategy, but the effects on wildlife in upland forests, especially those dominated by hardwood canopy species, are relatively unknown. We initiated our study to assess whether this management strategy affects eastern wild turkey reproductive ecology on the Ozark-St. Francis National Forest. We marked 67 wild turkey hens with Global Positioning System (GPS) Platform Transmitting Terminals in 2012 and 2013 to document exposure to prescribed fire, and estimate daily nest survival, nest success, and nest-site selection. We estimated these reproductive parameters in forest units managed with prescribed fire (treated) and units absent of prescribed fire (untreated). Of 60 initial nest attempts monitored, none were destroyed or exposed to prescribed fire because a majority of fires occurred early than a majority of the nesting activity. We found nest success was greater in untreated units than treated units (36.4% versus 14.6%). We did not find any habitat characteristic differences between successful and unsuccessful nest-sites. We found that nest-site selection criteria differed between treated and untreated units. Visual concealment and woody ground cover were common selection criteria in both treated and untreated units. However, in treated units wild turkey selected nest-sites with fewer small shrubs (<5 cm ground diameter) and large trees (>20 cm DBH) but not in untreated units. In untreated units wild turkey selected nest-sites with more large shrubs (≥5cm ground diameter) but did not select for small shrubs or large trees. Our findings suggest that wild turkey have not benefited from the reintroduction of prescribed fire to the WRERA. PMID:26795913

Impacts of Short-Rotation Early-Growing Season Prescribed Fire on a Ground Nesting Bird in the Central Hardwoods Region of North America.

PubMed

Pittman, H Tyler; Krementz, David G

2016-01-01

Landscape-scale short-rotation early-growing season prescribed fire, hereafter prescribed fire, in upland hardwood forests represents a recent shift in management strategies across eastern upland forests. Not only does this strategy depart from dormant season to growing season prescriptions, but the strategy also moves from stand-scale to landscape-scale implementation (>1,000 ha). This being so, agencies are making considerable commitments in terms of time and resources to this management strategy, but the effects on wildlife in upland forests, especially those dominated by hardwood canopy species, are relatively unknown. We initiated our study to assess whether this management strategy affects eastern wild turkey reproductive ecology on the Ozark-St. Francis National Forest. We marked 67 wild turkey hens with Global Positioning System (GPS) Platform Transmitting Terminals in 2012 and 2013 to document exposure to prescribed fire, and estimate daily nest survival, nest success, and nest-site selection. We estimated these reproductive parameters in forest units managed with prescribed fire (treated) and units absent of prescribed fire (untreated). Of 60 initial nest attempts monitored, none were destroyed or exposed to prescribed fire because a majority of fires occurred early than a majority of the nesting activity. We found nest success was greater in untreated units than treated units (36.4% versus 14.6%). We did not find any habitat characteristic differences between successful and unsuccessful nest-sites. We found that nest-site selection criteria differed between treated and untreated units. Visual concealment and woody ground cover were common selection criteria in both treated and untreated units. However, in treated units wild turkey selected nest-sites with fewer small shrubs (<5 cm ground diameter) and large trees (>20 cm DBH) but not in untreated units. In untreated units wild turkey selected nest-sites with more large shrubs (≥5 cm ground diameter) but did not select for small shrubs or large trees. Our findings suggest that wild turkey have not benefited from the reintroduction of prescribed fire to the WRERA.

Population Census of a Large Common Tern Colony with a Small Unmanned Aircraft

PubMed Central

Chabot, Dominique; Craik, Shawn R.; Bird, David M.

2015-01-01

Small unmanned aircraft systems (UAS) may be useful for conducting high-precision, low-disturbance waterbird surveys, but limited data exist on their effectiveness. We evaluated the capacity of a small UAS to census a large (>6,000 nests) coastal Common tern (Sterna hirundo) colony of which ground surveys are particularly disruptive and time-consuming. We compared aerial photographic tern counts to ground nest counts in 45 plots (5-m radius) throughout the colony at three intervals over a nine-day period in order to identify sources of variation and establish a coefficient to estimate nest numbers from UAS surveys. We also compared a full colony ground count to full counts from two UAS surveys conducted the following day. Finally, we compared colony disturbance levels over the course of UAS flights to matched control periods. Linear regressions between aerial and ground counts in plots had very strong correlations in all three comparison periods (R 2 = 0.972–0.989, P < 0.001) and regression coefficients ranged from 0.928–0.977 terns/nest. Full colony aerial counts were 93.6% and 94.0%, respectively, of the ground count. Varying visibility of terns with ground cover, weather conditions and image quality, and changing nest attendance rates throughout incubation were likely sources of variation in aerial detection rates. Optimally timed UAS surveys of Common tern colonies following our method should yield population estimates in the 93–96% range of ground counts. Although the terns were initially disturbed by the UAS flying overhead, they rapidly habituated to it. Overall, we found no evidence of sustained disturbance to the colony by the UAS. We encourage colonial waterbird researchers and managers to consider taking advantage of this burgeoning technology. PMID:25874997

Microplastic at nesting grounds used by the northern Gulf of Mexico loggerhead recovery unit.

PubMed

Beckwith, Valencia K; Fuentes, Mariana M P B

2018-06-01

Microplastics can impact key habitats used by endangered species, such as marine turtles. They impact the environment by transporting toxicants and altering sediment properties affecting temperature and sediment permeability. Our study determined the exposure of the ten most important nesting sites for the Northern Gulf of Mexico Loggerhead Recovery Unit to microplastic. Sand samples were obtained at each nesting site during the 2017 nesting season and analyzed for abundance and characteristics of microplastic. Microplastic was found at all sites, with an average abundance of 61.08 ± 34.61 pieces/m 2 , and 59.9% located at the dunes, where turtles primarily nest. A gradual decrease in microplastics abundance was observed from the most western nesting ground to the east. The results from this study indicate that microplastic accumulation on nesting sites for the Northern Gulf of Mexico may be of great concern, and could negatively affect the incubating environment for marine turtles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identifying effective actions to guide volunteer-based and nationwide conservation efforts for a ground-nesting farmland bird.

PubMed

Santangeli, Andrea; Arroyo, Beatriz; Millon, Alexandre; Bretagnolle, Vincent

2015-08-01

1. Modern farming practices threaten wildlife in different ways, and failure to identify the complexity of multiple threats acting in synergy may result in ineffective management. To protect ground-nesting birds in farmland, monitoring and mitigating impacts of mechanical harvesting is crucial. 2. Here, we use 6 years of data from a nationwide volunteer-based monitoring scheme of the Montagu's harrier, a ground-nesting raptor, in French farmlands. We assess the effectiveness of alternative nest protection measures and map their potential benefit to the species. 3. We show that unprotected nests in cultivated land are strongly negatively affected by harvesting and thus require active management. Further, we show that protection from harvesting alone (e.g. by leaving a small unharvested buffer around the nest) is impaired by post-harvest predation at nests that become highly conspicuous after harvest. Measures that simultaneously protect from harvesting and predation (by adding a fence around the nest) significantly enhance nest productivity. 4. The map of expected gain from nest protection in relation to available volunteers' workforce pinpoints large areas of high expected gain from nest protection that are not matched by equally high workforce availability. This mismatch suggests that the impact of nest protection can be further improved by increasing volunteer efforts in key areas where they are low relative to the expected gain they could have. 5. Synthesis and applications . This study shows that synergistic interplay of multiple factors (e.g. mechanical harvesting and predation) may completely undermine the success of well-intentioned conservation efforts. However, identifying areas where the greatest expected gains can be achieved relative to effort expended can minimize the risk of wasted volunteer actions. Overall, this study underscores the importance of citizen science for collecting large-scale data useful for producing science and ultimately informs large-scale evidence-based conservation actions within an adaptive management framework.

Molecular forensics in avian conservation: a DNA-based approach for identifying mammalian predators of ground-nesting birds and eggs.

PubMed

Hopken, Matthew W; Orning, Elizabeth K; Young, Julie K; Piaggio, Antoinette J

2016-01-07

The greater sage-grouse (Centrocercus urophasianus) is a ground-nesting bird from the Northern Rocky Mountains and a species at risk of extinction in in multiple U.S. states and Canada. Herein we report results from a proof of concept that mitochondrial and nuclear DNAs from mammalian predator saliva could be non-invasively collected from depredated greater sage-grouse eggshells and carcasses and used for predator species identification. Molecular forensic approaches have been applied to identify predators from depredated remains as one strategy to better understand predator-prey dynamics and guide management strategies. This can aid conservation efforts by correctly identifying predators most likely to impact threatened and endangered species. DNA isolated from non-invasive samples around nesting sites (e.g. fecal or hair samples) is one method that can increase the success and accuracy of predator species identification when compared to relying on nest remains alone. Predator saliva DNA was collected from depredated eggshells and carcasses using swabs. We sequenced two partial fragments of two mitochondrial genes and obtained microsatellite genotypes using canid specific primers for species and individual identification, respectively. Using this multilocus approach we were able to identify predators, at least down to family, from 11 out of 14 nests (79%) and three out of seven carcasses (47%). Predators detected most frequently were canids (86%), while other taxa included rodents, a striped skunk, and cattle. We attempted to match the genotypes of individual coyotes obtained from eggshells and carcasses with those obtained from fecal samples and coyotes collected in the areas, but no genotype matches were found. Predation is a main cause of nest failure in ground-nesting birds and can impact reproduction and recruitment. To inform predator management for ground-nesting bird conservation, accurate identification of predator species is necessary. Considering predation can have a high impact on recruitment, predation events are very difficult to observe, and predator species are difficult to identify visually from nest remains, molecular approaches that reduce the need to observe or handle animals offer an additional tool to better understand predator-prey dynamics at nesting sites.

Savanna chimpanzee (Pan troglodytes verus) nesting ecology at Bagnomba (Kedougou, Senegal).

PubMed

Badji, L; Ndiaye, P I; Lindshield, S M; Ba, C T; Pruetz, J D

2018-05-01

We studied the nesting behavior of the critically endangered West African chimpanzee (Pan troglodytes verus). We assumed that the nesting data stemmed from a single, unhabituated community at the Bagnomba hill site in the savanna-woodlands of southeastern Senegal. The aim of this study was to examine chimpanzees' nesting habits in terms of the tree species utilized and sleeping nest heights. We recorded a total of 550 chimpanzee nests at Bagnomba between January 2015 and December 2015. The chimpanzees here made nests in particular tree species more often than others. The majority of nests (63%) were in two tree species: Diospyros mespiliformis and Pterocarpus erinaceus. The average height of nesting trees was 10.54 m (SD 3.91, range, 0.0-29.0 m) and average nest height was 7.90 m (SD 3.62, range, 0.0-25.0 m). The result of a linear regression analysis (r = 0.7874; n = 550; p < 0.05) is consistent with a preference for nesting at a particular height. Bagnomba chimpanzees rarely made ground nests (0.36% of nests), but the presence of any ground nesting was unexpected, given that at least one leopard (Panthera pardus) also occupied the hill. This knowledge will enable stakeholders involved in the protection of chimpanzees specifically and of biodiversity in general to better understand chimpanzee ecology and inform a conservation action plan in Senegal where the survival of this species is threatened.

Late-Summer Nesting Sites of Quail in South Georgia

Treesearch

Thomas S. Harshbarger; Ronald C. Simpson

1970-01-01

An exploratory investigation in south Georgia indicates that quail seem to prefer freshly burned areas and 1-year roughs as late-summer nesting sites. Bluestem grasses were most frequently used as nesting cover and as nest sites, and optimum herbaceous cover appeared to be around 50 percent. Burning enhanced the condition of ground cover by promoting complexes...

Migratory patterns and population structure among breeding and wintering red-breasted mergansers (Mergus serrator) and common mergansers (M. merganser)

USGS Publications Warehouse

Pearce, J.M.; McCracken, K.G.; Christensen, Thomas K.; Zhuravlev, Y.N.

2009-01-01

Philopatry has long been assumed to structure populations of waterfowl and other species of birds genetically, especially via maternally transmitted mitochondrial DNA (mtDNA), yet other migratory behaviors and nesting ecology (use of ground vs. cavity sites) may also contribute to population genetic structure. We investigated the effects of migration and nesting ecology on the population genetic structure of two Holarctic waterfowl, the Red-breasted Merganser (Mergus serrator) and Common Merganser (M. merganser), using mtDNA control-region sequence data. Red-breasted Mergansers (a ground-nesting species) exhibited lower levels of population differentiation across their North American range, possibly as a result of post-Pleistocene range expansion and population growth. By contrast, Common Mergansers (a cavity-nesting species) breeding in western and eastern North America were strongly differentiated, as were continental groups in North America and Europe. Our hypothesis that population differentiation of breeding female Common Mergansers results from limited migration during non-breeding periods was not supported, in that equally heterogeneous mtDNA lineages were observed in males and females on several wintering areas. The interspecific differences in mtDNA patterns for these two closely related species may have resulted from factors related to nesting ecology (ground vs. cavity nesting) and responses to historical climate change.

Nest construction by a ground-nesting bird represents a potential trade-off between egg crypticity and thermoregulation.

PubMed

Mayer, Paul M; Smith, Levica M; Ford, Robert G; Watterson, Dustin C; McCutchen, Marshall D; Ryan, Mark R

2009-04-01

Predation selects against conspicuous colors in bird eggs and nests, while thermoregulatory constraints select for nest-building behavior that regulates incubation temperatures. We present results that suggest a trade-off between nest crypticity and thermoregulation of eggs based on selection of nest materials by piping plovers (Charadrius melodus), a ground-nesting bird that constructs simple, pebble-lined nests highly vulnerable to predators and exposed to temperature extremes. Piping plovers selected pebbles that were whiter and appeared closer in color to eggs than randomly available pebbles, suggesting a crypsis function. However, nests that were more contrasting in color to surrounding substrates were at greater risk of predation, suggesting an alternate strategy driving selection of white rocks. Near-infrared reflectance of nest pebbles was higher than randomly available pebbles, indicating a direct physical mechanism for heat control through pebble selection. Artificial nests constructed of randomly available pebbles heated more quickly and conferred heat to model eggs, causing eggs to heat more rapidly than in nests constructed from piping plover nest pebbles. Thermal models and field data indicated that temperatures inside nests may remain up to 2-6 degrees C cooler than surrounding substrates. Thermal models indicated that nests heat especially rapidly if not incubated, suggesting that nest construction behavior may serve to keep eggs cooler during the unattended laying period. Thus, pebble selection suggests a potential trade-off between maximizing heat reflectance to improve egg microclimate and minimizing conspicuous contrast of nests with the surrounding substrate to conceal eggs from predators. Nest construction behavior that employs light-colored, thermally reflective materials may represent an evolutionary response by birds and other egg-laying organisms to egg predation and heat stress.

Prey of nesting ospreys on the Willamette and Columbia Rivers, Oregon and Washington

USGS Publications Warehouse

Johnson, B.L.; Kaiser, J.L.; Henny, C.J.; Grove, R.A.

2008-01-01

To more effectively use ospreys as a biomonitoring tool and to better assess contaminant pathways, the diet of nesting ospreys (Pandion haliaetus) was studied along the lower Columbia and upper mainstem Willamette rivers by evaluating prey remains collected from wire baskets constructed under artificial feeding perches installed near nest sites and from the ground beneath natural feeding perches and nests. Prey remains from 1997-2004 on the Columbia River and 1993 (previously published) and 2001 on the Willamette River were evaluated and compared. Largescale suckers (Catostomus macrocheilus) were the predominate fish species identified in collections from the Columbia River (61.5% [84.3% biomass]) and Willamette River (76.0% [92.7% biomass]). Prey fish diversity, when based only on ground collections, was higher in the Columbia (2.45) than the Willamette river (1.92) (P = 0.038). Prey fish diversity in collections from the Willamette River did not differ between this study (2001) and previous study (1993) (P = 0.62). Fishbones recovered in wire baskets are likely more representative of osprey diet compared to bones recovered from the ground, because prey diversity was higher among basket samples compared to ground collections (wire basket diversity = 5.25 vs. ground collection diversity = 2.45, P = 0.011). Soft-boned salmonids (Oncorhynchus spp.), American shad (Alosa sapidissima), and mountain whitefish (Prosopium williamsoni) were probably underrepresented in collections obtained from the ground. Study results suggest that baskets provide a better method for assessing osprey diet than other indirect methods. These findings augment available osprey food-habits information and provide additional biological and ecological information to better assess potential impacts of various environmental contaminants on nesting ospreys.

The first nest records of the sooty antbird (Myrmeciza fortis) with notes on eggs and nestling development

USGS Publications Warehouse

Wilkinson, F.A.; Smith, U.R.

1997-01-01

Two Myrmeciza fortis nests were discovered in a lowland floodplain forest of Manu National Park, Peru. Both nests were embedded in leaf litter on the ground and were oven-shaped with a an entrance and an inner chamber concealing two eggs. Unlike the known nests of other Myrmeciza spp., the nests of Myrmeciza fortis closely resembled nests of other species in the Thamnophilidae. This discovery suggests that the genus Myrmeciza is polyphyletic

Nesting songbirds assess spatial heterogeneity of predatory chipmunks by eavesdropping on their vocalizations.

PubMed

Emmering, Quinn C; Schmidt, Kenneth A

2011-11-01

1. Information benefits organisms living in a heterogeneous world by reducing uncertainty associated with decision making. For breeding passerines, information reliably associated with nest failure, such as predator activity, can be used to adjust breeding decisions leading to higher reproductive success. 2. Predator vocalizations may provide a source of current information for songbirds to assess spatial heterogeneity in risk that enables them to make appropriate nest-site and territory placement decisions. 3. To determine whether ground-nesting passerines eavesdrop on a common nest predator, the eastern chipmunk (Tamias striatus), we conducted a playback experiment to create spatial heterogeneity in perceived predation risk. We established three types of playback plots broadcasting: (i) chipmunk vocalizations (increased risk), (ii) frog calls (procedural control) and (iii) no playback (silent control). We conducted point counts from plot centres to compare bird activity among treatments and measured the distance of two ground-nesting species' nests, ovenbird (Seiurus aurocapilla) and veery (Catharus fuscescens), from playback stations. 4. Ground-nesting birds significantly reduced their activities up to 30 m from plot centres in response to playbacks of chipmunk calls suggesting an adjustment of territory placement or a reduction of overt behaviours (e.g. singing frequency). In contrast, less vulnerable canopy-nesting species showed no effect across experimental plots. Correspondingly, veeries and ovenbirds nested significantly further from chipmunk playback stations relative to control stations. Interestingly, the magnitude of this response was more than twice as high in ovenbirds than in veeries. 5. Our findings indicate that some breeding passerines may eavesdrop on predator communication, providing an explanation for how some birds assess spatial heterogeneity in predation risk to make breeding site decisions. Thus, heterospecific eavesdropping may be a common feature of predator-prey interactions that allows birds to avoid nest predators in space and provide greater stability to predator-prey dynamics. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

Nest predation rates in managed and reserved extensive northern hardwood forests

Treesearch

Richard M. DeGraaf

1995-01-01

Depredation rates on artificial ground and shrub nests in large blocks of managed and remote reserved northern hardwood forests were studied in the White Mountain National Forest (WMNF) (303 930 ha) in New Hampshire, USA, from June to August 1991. Both types of nests were monitored by trip cameras that recorded depredations as eggs were removed. No differences in nest...

Use of artificial nests to investigate predation on freshwater turtle nests

Treesearch

Michael N. Marchand; John A. Litvaitis; Thomas J. Maier; Richard M. DeGraaf

2002-01-01

Habitat fragmentation has raised concerns that populations of generalist predators have increased and are affecting a diverse group of prey. Previous research has included the use of artificial nests to investigate the role of predation on birds that nest on or near the ground. Because predation also is a major factor limiting populations of freshwater turtles, we...

Potential sources of intra-population variation in the overwintering strategy of painted turtle (Chrysemys picta) hatchlings.

PubMed

Riley, Julia L; Tattersall, Glenn J; Litzgus, Jacqueline D

2014-12-01

Many temperate animals spend half their lives in a non-active, overwintering state, and multiple adaptations have evolved to enable winter survival. One notable vertebrate model is Chrysemys picta, whose hatchlings display dichotomous overwintering strategies: some hatchlings spend their first winter aquatically after nest emergence in the autumn, whereas others overwinter terrestrially within their natal nest with subsequent emergence in the spring. The occurrence of these strategies varies among populations and temporally within populations; however, factors that determine the strategy employed by a nest in nature are unknown. We examined potential factors that influence intra-population variation in the overwintering strategy of C. picta hatchlings over two winters in Algonquin Park, Ontario. We found that environmental factors may be a trigger for the hatchling overwintering strategy: autumn-emerging nests were sloped towards the water and were surrounded by a relatively higher percentage of bare ground compared with spring-emerging nests. Autumn-emerging hatchlings were also relatively smaller. Overwintering strategy was not associated with clutch oviposition sequence, or mammalian or avian predation attempts. Instead, autumn emergence from the nest was associated with the direct mortality threat of predation by sarcophagid fly larvae. Body condition and righting response, measured as proxies of hatchling fitness, did not differ between overwintering strategies. Costs and benefits of overwintering aquatically versus terrestrially in hatchling C. picta are largely unknown, and have the potential to affect population dynamics. Understanding winter survival has great implications for turtle ecology, thus we emphasize areas for future research on dichotomous overwintering strategies in temperate hatchling turtles. © 2014. Published by The Company of Biologists Ltd.

Host selection in the forest interior: cowbirds target ground-nesting species

USGS Publications Warehouse

Hahn, D.C.; Hatfield, J.S.

2000-01-01

We investigated patterns of cowbird host selection in a large (1300 ha), unfragmented forest in eastern New York in 1992-3 to determine whether cowbird parasitism rates can be attributed to species-specific traits or to other features associated with nest sites. Nest height was significantly associated with parasitism (P = 0.003) in this community of 23 species (n = 430 nests, 23% parasitized). Further analysis revealed that the difference in mean nest heights between parasitized and unparasitized nests was due to species identity, and within each species there was no difference in mean nest heights between parasitized and unparasitized nests. These results imply that during 1992-3 cowbirds in this forest specialized on species that have low nests and did not necessarily select low nests regardless of species. This was further supported by a negative association across all 23 species between mean nest height and parasitism rate (P = 0.03). Thus, although most of the forest-nesting species in this community experienced cowbird parasitism, there was a tendency for higher parasitism rates on low-nesting species such as the Ovenbird, Black-and-white Warbler, Louisiana Waterthrush, Veery, and Hermit Thrush. The Wood Thrush, a mid-range nester which is heavily parasitized in southern Illinois, experienced only 10% parasitism in our site and ranked 9th in parasitism rate, although it was the most abundant species in this forest in terms of the number of nests found. A long-term study is necessary to determine whether this cowbird population consistently parasitizes the ground-nesting species of this forest community more often than those nesting at higher levels or whether they periodically shift among hosts at different heights and in different habitats across the local landscape.

Numerical simulation of vertical ground-water flux of the Rio Grande from ground-water temperature profiles, central New Mexico

USGS Publications Warehouse

Bartolino, James R.; Niswonger, Richard G.

1999-01-01

An important gap in the understanding of the hydrology of the Middle Rio Grande Basin, central New Mexico, is the rate at which water from the Rio Grande recharges the Santa Fe Group aquifer system. Several methodologies-including use of the Glover-Balmer equation, flood pulses, and channel permeameters- have been applied to this problem in the Middle Rio Grande Basin. In the work presented here, ground-water temperature profiles and ground-water levels beneath the Rio Grande were measured and numerically simulated at four sites. The direction and rate of vertical ground-water flux between the river and underlying aquifer was simulated and the effective vertical hydraulic conductivity of the sediments underlying the river was estimated through model calibration. Seven sets of nested piezometers were installed during July and August 1996 at four sites along the Rio Grande in the Albuquerque area, though only four of the piezometer nests were simulated. In downstream order, these four sites are (1) the Bernalillo site, upstream from the New Mexico State Highway 44 bridge in Bernalillo (piezometer nest BRN02); (2) the Corrales site, upstream from the Rio Rancho sewage treatment plant in Rio Rancho (COR01); (3) the Paseo del Norte site, upstream from the Paseo del Norte bridge in Albuquerque (PDN01); and (4) the Rio Bravo site, upstream from the Rio Bravo bridge in Albuquerque (RBR01). All piezometers were completed in the inner-valley alluvium of the Santa Fe Group aquifer system. Ground-water levels and temperatures were measured in the four piezometer nests a total of seven times in the 24-month period from September 1996 through August 1998. The flux between the surface- and ground-water systems at each of the field sites was quantified by one-dimensional numerical simulation of the water and heat exchange in the subsurface using the heat and water transport model VS2DH. Model calibration was aided by the use of PEST, a model-independent computer program that uses nonlinear parameter estimation. Mean vertical hydraulic conductivities were estimated by model calibration and range from 1.5x10-5 to 5.8x10-6 meters per second (m/s). Mean simulated vertical ground-water flux for the BRN02 piezometer nest is 3.30x10-7 m/s; for the COR01 piezometer nest is 3.58x10-7 m/s; for the PDN01 piezometer nest is 4.22x10- 7 m/s; and for the RBR01 piezometer nest is 2.05x10-7 m/s. Comparison of the simulated vertical fluxes and vertical hydraulic conductivities derived from this study with values from other studies in the Middle Rio Grande Basin indicate agreement between 1 and 3.5 orders of magnitude for hydraulic conductivity and within 1 order of magnitude for vertical flux.

Eggs in the Freezer: Energetic Consequences of Nest Site and Nest Design in Arctic Breeding Shorebirds

PubMed Central

Tulp, Ingrid; Schekkerman, Hans; de Leeuw, Joep

2012-01-01

Birds construct nests for several reasons. For species that breed in the Arctic, the insulative properties of nests are very important. Incubation is costly there and due to an increasing surface to volume ratio, more so in smaller species. Small species are therefore more likely to place their nests in thermally favourable microhabitats and/or to invest more in nest insulation than large species. To test this hypothesis, we examined characteristics of nests of six Arctic breeding shorebird species. All species chose thermally favourable nesting sites in a higher proportion than expected on the basis of habitat availability. Site choice did not differ between species. Depth to frozen ground, measured near the nests, decreased in the course of the season at similar non-species-specific speeds, but this depth increased with species size. Nest cup depth and nest scrape depth (nest cup without the lining) were unrelated to body mass (we applied an exponent of 0.73, to account for metabolic activity of the differently sized species). Cup depth divided by diameter2 was used as a measure of nest cup shape. Small species had narrow and deep nests, while large species had wide shallow nests. The thickness of nest lining varied between 0.1 cm and 7.6 cm, and decreased significantly with body mass. We reconstruct the combined effect of different nest properties on the egg cooling coefficient using previously published quantitative relationships. The predicted effect of nest cup depth and lining depth on heat loss to the frozen ground did not correlate with body mass, but the sheltering effect of nest cup diameter against wind and the effects of lining material on the cooling coefficient increased with body mass. Our results suggest that small arctic shorebirds invest more in the insulation of their nests than large species. PMID:22701596

A meta-analysis of lesser prairie-chicken nesting and brood-rearing habitats: implications for habitat management

USGS Publications Warehouse

Hagen, Christian A.; Grisham, Blake A.; Boal, Clint W.; Haukos, David A.

2013-01-01

The distribution and range of lesser prairie-chicken (Tympanuchus pallidicinctus) has been reduced by >90% since European settlement of the Great Plains of North America. Currently, lesser prairie-chickens occupy 3 general vegetation communities: sand sagebrush (Artemisia filifolia), sand shinnery oak (Quercus havardii), and mixed-grass prairies juxtaposed with Conservation Reserve Program grasslands. As a candidate for protection under the Endangered Species Act, there is a need for a synthesis that characterizes habitat structure rangewide. Thus, we conducted a meta-analysis of vegetation characteristics at nest sites and brood habitats to determine whether there was an overall effect (Hedges' d) of habitat selection and to estimate average (95% CI) habitat characteristics at use sites. We estimated effect sizes (di) from the difference between use (nests and brood sites) and random sampling sites for each study (n = 14), and derived an overall effect size (d++). There was a general effect for habitat selection as evidenced by low levels of variation in effect sizes across studies and regions. There was a small to medium effect (d++) = 0.20-0.82) of selection for greater vertical structure (visual obstruction) by nesting females in both vegetation communities, and selection against bare ground (d++ = 0.20-0.58). Females with broods exhibited less selectivity for habitat components except for vertical structure. The variation of d++ was greater during nesting than brooding periods, signifying a seasonal shift in habitat use, and perhaps a greater range of tolerance for brood-rearing habitat. The overall estimates of vegetation cover were consistent with those provided in management guidelines for the species.

A simple, physiologically-based model of sea turtle remigration intervals and nesting population dynamics: Effects of temperature.

PubMed

Neeman, Noga; Spotila, James R; O'Connor, Michael P

2015-09-07

Variation in the yearly number of sea turtles nesting at rookeries can interfere with population estimates and obscure real population dynamics. Previous theoretical models suggested that this variation in nesting numbers may be driven by changes in resources at the foraging grounds. We developed a physiologically-based model that uses temperatures at foraging sites to predict foraging conditions, resource accumulation, remigration probabilities, and, ultimately, nesting numbers for a stable population of sea turtles. We used this model to explore several scenarios of temperature variation at the foraging grounds, including one-year perturbations and cyclical temperature oscillations. We found that thermally driven resource variation can indeed synchronize nesting in groups of turtles, creating cohorts, but that these cohorts tend to break down over 5-10 years unless regenerated by environmental conditions. Cohorts were broken down faster at lower temperatures. One-year perturbations of low temperature had a synchronizing effect on nesting the following year, while high temperature perturbations tended to delay nesting in a less synchronized way. Cyclical temperatures lead to cyclical responses both in nesting numbers and remigration intervals, with the amplitude and lag of the response depending on the duration of the cycle. Overall, model behavior is consistent with observations at nesting beaches. Future work should focus on refining the model to fit particular nesting populations and testing further whether or not it may be used to predict observed nesting numbers and remigration intervals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Predation of artificial ground nests on white-tailed prairie dog colonies

USGS Publications Warehouse

Baker, B.W.; Stanley, T.R.; Sedgwick, J.A.

1999-01-01

Prairie dog (Cynomys spp.) colonies are unique to prairie and shrub-steppe landscapes. However, widespread eradication, habitat loss, and sylvatic plague (Yersinia pestis) have reduced their numbers by 98% since historical times. Birds associated with prairie dogs also are declining. Potential nest predators, such as coyotes (Canis latrans), swift foxes (Vulpes velox), and badgers (Taxidea taxus), may be attracted to colonies where a high concentration of prairie dogs serve as available prey. Increased abundance of small mammals, including prairie dogs, also may increase the risk of predation for birds nesting on colonies. Finally, because grazing by prairie dogs may decrease vegetation height and canopy cover, bird nests may be easier for predators to locate. In this study, we placed 1,444 artificial ground nests on and off 74 white-tailed prairie dog (C. leucurus) colonies to test the hypothesis that nest predation rates are higher on colonies than at nearby off sites (i.e., uncolonized habitat). We sampled colonies from 27 May to 16 July 1997 at the following 3 complexes: Coyote Basin, Utah and Colorado; Moxa Arch, Wyoming; and Shirley Basin, Wyoming. Differences in daily predation rates between colonies and paired off sites averaged 1.0% (P = 0.060). When converted to a typical 14-day incubation period, predation rates averaged 14% higher on colonies (57.7 ?? 2.7%; ?? ?? SE) than at off sites (50.4 ?? 3.1%). Comparisons of habitat variables on colonies to off sites showed percent canopy cover of vegetation was similar (P = 0.114), percent bare ground was higher on colonies (P 0.288). Although we found the risk of nest predation was higher on white-tailed prairie dog colonies than at off sites, fitness of birds nesting on colonies might depend on other factors that influence foraging success, reproductive success, or nestling survival.

Inferring Foraging Areas of Nesting Loggerhead Turtles Using Satellite Telemetry and Stable Isotopes

PubMed Central

Ceriani, Simona A.; Roth, James D.; Evans, Daniel R.; Weishampel, John F.; Ehrhart, Llewellyn M.

2012-01-01

In recent years, the use of intrinsic markers such as stable isotopes to link breeding and foraging grounds of migratory species has increased. Nevertheless, several assumptions still must be tested to interpret isotopic patterns found in the marine realm. We used a combination of satellite telemetry and stable isotope analysis to (i) identify key foraging grounds used by female loggerheads nesting in Florida and (ii) examine the relationship between stable isotope ratios and post-nesting migration destinations. We collected tissue samples for stable isotope analysis from 14 females equipped with satellite tags and an additional 57 untracked nesting females. Telemetry identified three post-nesting migratory pathways and associated non-breeding foraging grounds: (1) a seasonal continental shelf–constrained migratory pattern along the northeast U.S. coastline, (2) a non-breeding residency in southern foraging areas and (3) a residency in the waters adjacent to the breeding area. Isotopic variability in both δ13C and δ15N among individuals allowed identification of three distinct foraging aggregations. We used discriminant function analysis to examine how well δ13C and δ15N predict female post-nesting migration destination. The discriminant analysis classified correctly the foraging ground used for all but one individual and was used to predict putative feeding areas of untracked turtles. We provide the first documentation that the continental shelf of the Mid- and South Atlantic Bights are prime foraging areas for a large number (61%) of adult female loggerheads from the largest loggerhead nesting population in the western hemisphere and the second largest in the world. Our findings offer insights for future management efforts and suggest that this technique can be used to infer foraging strategies and residence areas in lieu of more expensive satellite telemetry, enabling sample sizes that are more representative at the population level. PMID:23028943

Density and success of bird nests relative to grazing on western Montana grasslands

USGS Publications Warehouse

Fondell, Thomas F.; Ball, I.J.

2004-01-01

Grassland birds are declining at a faster rate than any other group of North American bird species. Livestock grazing is the primary economic use of grasslands in the western United States, but the effects of this use on distribution and productivity of grassland birds are unclear. We examined nest density and success of ground-nesting birds on grazed and ungrazed grasslands in western Montana. In comparison to grazed plots, ungrazed plots had reduced forb cover, increased litter cover, increased litter depth, and increased visual obstruction readings (VOR) of vegetation. Nest density among 10 of 11 common bird species was most strongly correlated with VOR of plots, and greatest nest density for each species occurred where mean VOR of the plot was similar to mean VOR at nests. Additionally, all bird species were relatively consistent in their choice of VOR at nests despite substantial differences in VOR among plots. We suggest that birds selected plots based in part on availability of suitable nest sites and that variation in nest density relative to grazing reflected the effect of grazing on availability of nest sites. Nest success was similar between grazed plots and ungrazed plots for two species but was lower for nests on grazed plots than on ungrazed plots for two other species because of increased rates of predation, trampling, or parasitism by brown-headed cowbirds (Molothrus ater). Other species nested almost exclusively on ungrazed plots (six species) or grazed plots (one species), precluding evaluation of the effects of grazing on nest success. We demonstrate that each species in a diverse suite of ground-nesting birds preferentially used certain habitats for nesting and that grazing altered availability of preferred nesting habitats through changes in vegetation structure and plant species composition. We also show that grazing directly or indirectly predisposed some bird species to increased nesting mortality. Management alternatives that avoid intensive grazing during the breeding season would be expected to benefit many grassland bird species.

Buteo Nesting Ecology: Evaluating Nesting of Swainson's Hawks in the Northern Great Plains.

PubMed

Inselman, Will M; Datta, Shubham; Jenks, Jonathan A; Jensen, Kent C; Grovenburg, Troy W

2015-01-01

Swainson's hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson's hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson's hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, SDist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%-42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson's hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson's hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson's hawks arriving to the breeding grounds.

'Bee hotels' as tools for native pollinator conservation: a premature verdict?

PubMed

MacIvor, J Scott; Packer, Laurence

2015-01-01

Society is increasingly concerned with declining wild bee populations. Although most bees nest in the ground, considerable effort has centered on installing 'bee hotels'--also known as nest boxes or trap nests--which artificially aggregate nest sites of above ground nesting bees. Campaigns to 'save the bees' often promote these devices despite the absence of data indicating they have a positive effect. From a survey of almost 600 bee hotels set up over a period of three years in Toronto, Canada, introduced bees nested at 32.9% of sites and represented 24.6% of more than 27,000 total bees and wasps recorded (47.1% of all bees recorded). Native bees were parasitized more than introduced bees and females of introduced bee species provisioned nests with significantly more female larva each year. Native wasps were significantly more abundant than both native and introduced bees and occupied almost 3/4 of all bee hotels each year; further, introduced wasps were the only group to significantly increase in relative abundance year over year. More research is needed to elucidate the potential pitfalls and benefits of using bee hotels in the conservation and population dynamics of wild native bees.

KENNEDY SPACE CENTER, FLA. -- A breeding osprey occupies a nest constructed on a speaker pole in the lower parking lot of the KSC Press Site. Eggs have been sighted in the nest. The NASA logo in the background is painted on an outer wall of the 525-foot-tall Vehicle Assembly Building nearby. Known as a fish hawk, the osprey selects sites of opportunity in which to nest -- from trees and telephone poles to rocks or even flat ground. In North America, it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

NASA Image and Video Library

2004-01-14

KENNEDY SPACE CENTER, FLA. -- A breeding osprey occupies a nest constructed on a speaker pole in the lower parking lot of the KSC Press Site. Eggs have been sighted in the nest. The NASA logo in the background is painted on an outer wall of the 525-foot-tall Vehicle Assembly Building nearby. Known as a fish hawk, the osprey selects sites of opportunity in which to nest -- from trees and telephone poles to rocks or even flat ground. In North America, it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

KENNEDY SPACE CENTER, FLA. -- A pair of breeding ospreys share a nest constructed on a speaker pole in the lower parking lot of the KSC Press Site. Eggs have been sighted in the nest. The NASA logo in the background is painted on an outer wall of the 525-foot-tall Vehicle Assembly Building nearby. Known as a fish hawk, the osprey selects sites of opportunity in which to nest -- from trees and telephone poles to rocks or even flat ground. In North America, it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

NASA Image and Video Library

2004-01-14

KENNEDY SPACE CENTER, FLA. -- A pair of breeding ospreys share a nest constructed on a speaker pole in the lower parking lot of the KSC Press Site. Eggs have been sighted in the nest. The NASA logo in the background is painted on an outer wall of the 525-foot-tall Vehicle Assembly Building nearby. Known as a fish hawk, the osprey selects sites of opportunity in which to nest -- from trees and telephone poles to rocks or even flat ground. In North America, it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

Rhodamine-Injected Eggs to Photographically Identify Small Nest-Predators

Treesearch

Thomas J. Maier; Richard M. DeGraaf

2000-01-01

Photographs that clearly disclose avian-nest predators are difficult to obtain, particularly when predators are small and exhibit subtle depredatory behavior. We exposed House Sparrow (Passer domesticus) eggs injected with Rhodamine B dye in camera-monitored ground nests for 12-d periods at 76 sites within mixed-hardwood forest stands in central...

Strengths and Weaknesses of NESTs and NNESTs: Perceptions of NNESTs in Hong Kong

ERIC Educational Resources Information Center

Ma, Lai Ping Florence

2012-01-01

Since non-native English speaking teachers (NNESTs) are always compared with native English speaking teachers (NESTs) on linguistic grounds, their strengths and weaknesses as English teachers are worthy of investigation. This paper reports on a mixed methods study which examines the strengths and weaknesses of NNESTs and NESTs through the…

Chapter 15: Inland Habitat Suitability for the Marbled Murrelet in Southcentral Alaska

Treesearch

Katherine J. Kuletz; Dennis K. Marks; Nancy L. Naslund; Nike J. Goodson; Mary B. Cody

1995-01-01

The majority of Marbled Murrelets (Brachyramphus marmoratus) nest in Alaska, where they sometimes nest on the ground, and their nesting habitat requirements are not well understood. The inland activity of murrelets was surveyed, and habitat features measured, between 1991 and 1993, in Prince William Sound, Kenai Fjords National Park and Afognak...

Reproductive plasticity and landscape heterogeneity benefit a ground-nesting bird in a fire-prone ecosystem.

PubMed

Carroll, J Matthew; Hovick, Torre J; Davis, Craig A; Elmore, Robert Dwayne; Fuhlendorf, Samuel D

2017-10-01

Disturbance is critical for the conservation of rangeland ecosystems worldwide and many of these systems are fire dependent. Although it is well established that restoring fire as an ecological process can lead to increased biodiversity in grasslands and shrublands, the underlying mechanisms driving community patterns are poorly understood for fauna in fire-prone landscapes. Much of this uncertainty stems from the paucity of studies that examine the effects of fire at scales relevant to organism life histories. We assessed the response of a non-migratory ground-dwelling bird to disturbance (i.e., prescribed fire) and environmental stochasticity over the course of a 4-yr period, which spanned years of historic drought and record rainfall. Specifically, we investigated the nesting ecology of Northern Bobwhite (Colinus virginianus; hereafter Bobwhite) to illuminate possible avenues by which individuals respond to dynamic landscape patterns during a critical reproductive stage (i.e., nesting) in a mixed-grass shrubland in western Oklahoma, USA. We found that Bobwhites exhibited extreme plasticity in nest substrate use among time since fire categories (TSF) and subsequently maintained high nest survival (e.g., 57-70%). Bobwhites were opportunistic in nest substrate use among TSF categories (i.e., 72% of nest sites in shrubs in 0-12 months post fire compared to 71% in herbaceous vegetation in >36 months post fire), yet nesting decisions were first filtered by similar structural components (i.e., vertical and horizontal cover) within the vicinity of nest sites regardless of TSF category. Despite being a non-migratory and comparatively less mobile ground-nesting bird species, Bobwhites adjusted to dynamic vegetation mosaics on a fire-prone landscape under stochastic climatic conditions that culminated in stable and high nest survival. Broadly, our findings provide a unique depiction of organism response strategies to fire at scales relevant to a critical life-stage, a topic that has been previously understudied and poorly understood. We also demonstrate how doing so can better inform conservation practices aimed at restoring fire regimes on grassland and shrubland landscapes. © 2017 by the Ecological Society of America.

Renesting by dusky Canada geese on the Copper River Delta, Alaska

USGS Publications Warehouse

Fondell, Thomas F.; Grand, James B.; Miller, David A.W.; Anthony, R. Michael

2006-01-01

The population of dusky Canada geese (Branta canadensis occidentalis; hereafter duskies) breeding on the Copper River Delta (CRD), Alaska, USA, has been in long-term decline, largely as a result of reduced productivity. Estimates of renesting rates by duskies may be useful for adjusting estimates of the size of the breeding population derived from aerial surveys and for understanding population dynamics. We used a marked population of dusky females to obtain estimates of renesting propensity and renesting interval on the CRD, 1999–2000. Continuation nests, replacement nests initiated without a break in the laying sequence, resulted only after first nests were destroyed in the laying stage with ≤4 eggs laid. Renesting propensity declined with nest age from 72% in mid-laying to 30% in early incubation. Between first nests and renests, mean interval was 11.9 ± 0.6 days, mean distance was 74.5 m (range 0–214 m), and clutch size declined 0.9 ± 0.4 eggs. We incorporated our renesting estimates and available estimates of other nesting parameters into an individual-based model to predict the proportion of first nests, continuation nests, and renests, and to examine female success on the CRD, 1997–2000. Our model predicted that 19–36% of nests each year were continuation nests and renests. Also, through 15 May (the approx. date of breeding ground surveys), 1.1–1.3 nests were initiated per female. Thus, the number of nests per female would have a significant, though relatively consistent, effect on adjusting the relation between numbers of nests found on ground surveys versus numbers of birds seen during aerial surveys. We also suggest a method that managers could use to predict nests per female using nest success of early nests. Our model predicted that relative to observed estimates of nest success, female success was 32–100% greater, due to replacement nests. Thus, although nest success remains low, production for duskies was higher than previously thought. For dusky Canada geese, managers need to consider both continuation nests and renests in designing surveys and in calculating adjustment factors for the expansion of aerial survey data using nest densities.

Reproductive strategies of northern geese: Why wait?

USGS Publications Warehouse

Ely, Craig R.; Bollinger, K.S.; Densmore, R.V.; Rothe, T.C.; Petrula, M.J.; Takekawa, John Y.; Orthmeyer, D.L.

2007-01-01

Migration and reproductive strategies in waterbirds are tightly linked, with timing of arrival and onset of nesting having important consequences for reproductive success. Whether migratory waterbirds are capital or income breeders is predicated by their spring migration schedule, how long they are on breeding areas before nesting, and how adapted they are to exploiting early spring foods at northern breeding areas. However, for most species, we know little about individual migration schedules, arrival times, and duration of residence on breeding areas before nesting. To document these relationships in a northern nesting goose, we radiotracked winter-marked Tule Greater White-fronted Geese (Anser albifrons elgasi; hereafter “Tule Geese”; n = 116) from the time of their arrival in Alaska through nesting. Tule Geese arrived on coastal feeding areas in mid-April and moved to nesting locations a week later. They initiated nests 15 days (range: 6–24 days) after arrival, a period roughly equivalent to the duration of rapid follicle growth. Tule Geese that arrived the earliest were more likely to nest than geese that arrived later; early arrivals also spent more time on the breeding grounds and nested earlier than geese that arrived later. The length of the prenesting period was comparable to that of other populations of this species, but longer than for goose species that initiate rapid follicle growth before arrival on the breeding grounds. We suggest that Tule Geese nesting in more temperate climates are more likely to delay breeding to exploit local food resources than Arctic-nesting species that may be constrained by short growing seasons.

Post-independence fledgling ecology in a migratory songbird: Implications for breeding-grounds conservation

USGS Publications Warehouse

Streby, H.M.; Peterson, S.M.; Kramer, G.R.; Anderson, D.E.

2014-01-01

For migratory songbirds, breeding-grounds conservation and management plans are generally focused on habitat associated with locations of singing males and sometimes nesting females. However, habitat structure is often different in areas used for raising fledglings compared with areas used for song territories, and very little is known about habitat use by fledglings after independence from adult care. From 2010 to 2012, we used radiotelemetry to monitor 68 fledgling golden-winged warblers Vermivora chrysoptera after independence from adult care in mixed managed forests of Minnesota, US and Manitoba, Canada. This species is of high conservation concern in the US, is listed as threatened in Canada and is listed as near threatened on the International Union for Conservation of Nature Red List. We assessed distance and orientation of independent fledgling movements and we used compositional analysis to test for selection among cover types. Fledglings of this species, commonly described as a shrubland specialist, selected mature forest (78% of locations) over all other cover types, and foraged in forest canopy and understory in mixed-species flocks. Fledgling golden-winged warbler movements were apparently associated with habitat optimization (although prioritizing foraging over predator avoidance), and likely not with commencement of migration, or scouting future breeding territories. Ten days after independence, fledglings were an average of 1238 m north of their nest, which may be related to homing-target formation and the species' northward range expansion. We conclude that consideration for independent fledgling habitat associations is necessary for developing full-fledged forest management plans on the breeding grounds of migratory songbirds.

Ratios of colony mass to thermal conductance of tree and man-made nest enclosures of Apis mellifera: implications for survival, clustering, humidity regulation and Varroa destructor

NASA Astrophysics Data System (ADS)

Mitchell, Derek

2016-05-01

In the absence of human intervention, the honeybee ( Apis mellifera L.) usually constructs its nest in a tree within a tall, narrow, thick-walled cavity high above the ground (the enclosure); however, most research and apiculture is conducted in the thin-walled, squat wooden enclosures we know as hives. This experimental research, using various hives and thermal models of trees, has found that the heat transfer rate is approximately four to seven times greater in the hives in common use, compared to a typical tree enclosure in winter configuration. This gives a ratio of colony mass to lumped enclosure thermal conductance (MCR) of less than 0.8 kgW-1 K for wooden hives and greater than 5 kgW-1 K for tree enclosures. This result for tree enclosures implies higher levels of humidity in the nest, increased survival of smaller colonies and lower Varroa destructor breeding success. Many honeybee behaviours previously thought to be intrinsic may only be a coping mechanism for human intervention; for example, at an MCR of above 2 kgW-1 K, clustering in a tree enclosure may be an optional, rare, heat conservation behaviour for established colonies, rather than the compulsory, frequent, life-saving behaviour that is in the hives in common use. The implied improved survival in hives with thermal properties of tree nests may help to solve some of the problems honeybees are currently facing in apiculture.

Importance of structural stability to success of mourning dove nests

USGS Publications Warehouse

Coon, R.A.; Nichols, J.D.; Percival, H.F.

1981-01-01

Studies of nest-site selection and nesting habitats often involve a "characterization" of nests and of habitats in which nests are found. Our objective in the present work is to identify nest-site characteristics that are associated with variation in components of Mourning Dove (Zenaida macroura) fitness (e.g. the probability of a nest succeeding), as opposed to simply "characterizing" dove nest sites. If certain nest- site characteristics affect the probability that a nest will succeed, then we suspect that these characteristics will be associated with either concealment (the probability of detection by certain predators) or structural stability (the probability of eggs or entire nests falling to the ground as a result of wind, rain storms, parental activity, etc.). Although other workers agree that structural stability is an important determinant of Mourning Dove nesting success (e.g. McClure 1944: 384; Woolfenden and Rohwer 1969: 59), we are aware of no actual tests of this hypothesis.

Buteo Nesting Ecology: Evaluating Nesting of Swainson’s Hawks in the Northern Great Plains

PubMed Central

Inselman, Will M.; Datta, Shubham; Jenks, Jonathan A.; Jensen, Kent C.; Grovenburg, Troy W.

2015-01-01

Swainson’s hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson’s hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson’s hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, S Dist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%–42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson’s hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson’s hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson’s hawks arriving to the breeding grounds. PMID:26327440

Present and future thermal environments available to Sharp-tailed Grouse in an intact grassland.

PubMed

Raynor, Edward J; Powell, Larkin A; Schacht, Walter H

2018-01-01

Better understanding animal ecology in terms of thermal habitat use has become a focus of ecological studies, in large part due to the predicted temperature increases associated with global climate change. To further our knowledge on how ground-nesting endotherms respond to thermal landscapes, we examined the thermal ecology of Sharp-tailed Grouse (Tympanuchus phasianellus) during the nesting period. We measured site-specific iButton temperatures (TiB) and vegetation characteristics at nest sites, nearby random sites, and landscape sites to assess thermal patterns at scales relevant to nesting birds. We asked if microhabitat vegetation characteristics at nest sites matched the characteristics that directed macrohabitat nest-site selection. Grouse selected sites sheltered by dense vegetation for nesting that moderated TiB on average up to 2.7°C more than available landscape sites. Successful nests were positioned in a way that reduced exposure to thermal extremes by as much as 4°C relative to failed nests with an overall mean daytime difference (±SE) of 0.4 ±0.03°C. We found that macrohabitat nest-site selection was guided by dense vegetation cover and minimal bare ground as also seen at the microhabitat scale. Global climate projections for 2080 suggest that TiB at nest sites may approach temperatures currently avoided on the landscape, emphasizing a need for future conservation plans that acknowledge fine-scale thermal space in climate change scenarios. These data show that features of grassland landscapes can buffer organisms from unfavorable microclimatic conditions and highlight how thermal heterogeneity at the individual-level can drive decisions guiding nest site selection.

Present and future thermal environments available to Sharp-tailed Grouse in an intact grassland

PubMed Central

Powell, Larkin A.; Schacht, Walter H.

2018-01-01

Better understanding animal ecology in terms of thermal habitat use has become a focus of ecological studies, in large part due to the predicted temperature increases associated with global climate change. To further our knowledge on how ground-nesting endotherms respond to thermal landscapes, we examined the thermal ecology of Sharp-tailed Grouse (Tympanuchus phasianellus) during the nesting period. We measured site-specific iButton temperatures (TiB) and vegetation characteristics at nest sites, nearby random sites, and landscape sites to assess thermal patterns at scales relevant to nesting birds. We asked if microhabitat vegetation characteristics at nest sites matched the characteristics that directed macrohabitat nest-site selection. Grouse selected sites sheltered by dense vegetation for nesting that moderated TiB on average up to 2.7°C more than available landscape sites. Successful nests were positioned in a way that reduced exposure to thermal extremes by as much as 4°C relative to failed nests with an overall mean daytime difference (±SE) of 0.4 ±0.03°C. We found that macrohabitat nest-site selection was guided by dense vegetation cover and minimal bare ground as also seen at the microhabitat scale. Global climate projections for 2080 suggest that TiB at nest sites may approach temperatures currently avoided on the landscape, emphasizing a need for future conservation plans that acknowledge fine-scale thermal space in climate change scenarios. These data show that features of grassland landscapes can buffer organisms from unfavorable microclimatic conditions and highlight how thermal heterogeneity at the individual-level can drive decisions guiding nest site selection. PMID:29415080

[Recent fauna of ground-nesting birds in Transvolga steppes and its dynamics in the 20th century].

PubMed

Oparin, M L

2008-01-01

It is shown that the structure of the ground-nesting bird fauna in Transvolga steppes has changed during the 20th century. The complex of lark species characteristic of true and dry steppe has disappeared because of climate change and impact of economic activity (the establishment of windbreak and roadside forest strips), which has provided for a sharp increase in the abundance of corvid birds.

Nest survival of clay-colored and vesper sparrows in relation to woodland edge in mixed-grass prairies

USGS Publications Warehouse

Grant, T.A.; Madden, E.M.; Shaffer, T.L.; Pietz, P.J.; Berkey, G.B.; Kadrmas, N.J.

2006-01-01

The quantity and quality of northern mixed-grass prairie continues to decline because of conversion to agriculture, invasion of woody and exotic plants, and disruption of important ecological processes that shape grasslands. Declines in grassland bird populations in North Dakota, USA, have coincided with these largely anthropogenic alterations to prairie habitat. In grasslands of north-central and northwestern North Dakota, woody plants have increased due primarily to fire suppression, extirpation of bison (Bos bison), and widescale planting of tree shelter belts. In northern grasslands, effects of woody vegetation on survival of grassland birds are poorly understood, and conclusions are based mainly on studies conducted outside the region. We examined nest survival of clay-colored sparrows (Spizella pallida) and vesper sparrows (Pooecetes gramineus) relative to the distance nests were located from aspen (Populus tremuloides,) woodland edges and relative to other habitat features near the nest. Clay-colored and vesper sparrow nest survival was higher for nests located near woodland edges, nests with greater cover of Kentucky bluegrass (Poa pratensis), and nests more concealed by vegetation. Vesper sparrow nest survival increased as the percent cover of tall shrubs near the nest increased. Based on video-camera data, the 13-lined ground squirrel (Spermophilus tridecemlineatus,) was the most common predator of sparrow eggs and young. Thirteen-lined ground squirrels were more common far from woodland edges than near, and this pattern may, in part, explain clay-colored and vesper sparrow nest survival in relation to woodland edges. In contrast to our results, studies conducted in other grassland systems generally report lower nest survival for grassland birds nesting near trees and shrubs. This disparity in results demonstrates the need to identify specific nest predators and their distributions with respect to important habitat features because these data can be important in explaining-and perhaps predicting-patterns of nest predation.

Unusual raptor nests around the world

USGS Publications Warehouse

Ellis, D.H.; Craig, T.; Craig, E.; Postupalsky, S.; LaRue, C.T.; Nelson, R.W.; Anderson, D.W.; Henny, C.J.; Watson, J.; Millsap, B.A.; Dawson, J.W.; Cole, K.L.; Martin, E.M.; Margalida, A.; Kung, P.

2009-01-01

From surveys in many countries, we report raptors using unusual nesting materials (e.g., paper money, rags, metal, antlers, and large bones) and unusual nesting situations. For example, we documented nests of Steppe Eagles Aquila nipalensis and Upland Buzzards Buteo hemilasius on the ground beside well-traveled roads, Saker Falcon Falco cherrug eyries in attics and a cistern, and Osprey Pandion haliaetus nests on the masts of boats and on a suspended automobile. Other records include a Golden Eagle A. chrysaetos nest 7.0 m in height, believed to be the tallest nest ever described, and, for the same species, we report nesting in rudimentary nests. Some nest sites are within a few meters of known predators or competitors. These unusual observations may be important in revealing the plasticity of a species' behavioral repertoire. ?? 2009 The Raptor Research Foundation, Inc.

KENNEDY SPACE CENTER, FLA. -- A pair of breeding ospreys have taken up residence in a nest constructed on a speaker pole in the lower parking lot of the KSC Press Site. Eggs have been sighted in the nest. The NASA logo in the background is painted on an outer wall of the 525-foot-tall Vehicle Assembly Building nearby. Known as a fish hawk, the osprey selects sites of opportunity in which to nest -- from trees and telephone poles to rocks or even flat ground. In North America, it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

NASA Image and Video Library

2004-01-14

KENNEDY SPACE CENTER, FLA. -- A pair of breeding ospreys have taken up residence in a nest constructed on a speaker pole in the lower parking lot of the KSC Press Site. Eggs have been sighted in the nest. The NASA logo in the background is painted on an outer wall of the 525-foot-tall Vehicle Assembly Building nearby. Known as a fish hawk, the osprey selects sites of opportunity in which to nest -- from trees and telephone poles to rocks or even flat ground. In North America, it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

Artificial nest predation in hedgerows and scrub forest in a human-dominated landscape of central Mexico

NASA Astrophysics Data System (ADS)

Zuria, Iriana; Gates, J. Edward; Castellanos, Ignacio

2007-03-01

Hedgerows as well as other narrow corridors could be valuable habitats for birds in regions of intensive agriculture, however, it is still not clear how successful breeding birds are in different types of hedgerows as compared to birds nesting in their natural habitats. We used artificial nests to examine whether hedgerows were sinks (ecological traps) for birds by comparing rates of predation in two types of hedgerows with different vegetation structure (simple and complex), and in a tract of scrub forest in an agricultural landscape of central Mexico. We determined also the types of predators responsible for egg predation. Ground and elevated nests were baited with one Japanese quail Coturnix japonica egg and one plasticine egg and placed alternately along transects. Significantly, greater predation rates were found in scrub forest and complex hedgerows than in simple hedgerows. Higher predation rates in complex habitats seemed to reflect the higher number of predator types found there. The most important predator types were carnivores followed by rodents, birds, and humans. Carnivores and rodents mainly predated ground nests, whereas birds and humans predated elevated nests. Simple hedgerows in this landscape appeared to offer relatively safe nest sites in terms of predation pressure when compared to more complex habitats (complex hedgerows and scrub forest).

Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain

USGS Publications Warehouse

Bentzen, R.L.; Powell, A.N.; Suydam, R.S.

2008-01-01

King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2 sites, Teshekpuk and Kuparuk, Alaska, USA, 2002-2005. We evaluated both a priori and exploratory competing models of nest survival that considered importance of nest concealment, seclusion, and incubation constancy as strategies to avoid 2 primary egg predators, avian (Larus spp., Stercorarius spp., and Corvus corax) and fox (Alopex lagopus). We used generalized nonlinear techniques to examine factors affecting nest survival rates and information-theoretic approaches to select among competing models. Estimated nest survival, accounting for a nest visitation effect, varied considerably across sites and years (0.21-0.57); however, given our small sample size, much of this variation maybe attributable to sampling variation (??process = 0.007, 95% CI: 0.003-0.070). Nest survival was higher at Kuparuk than Teshekpuk in all years; however, due to the correlative nature of our data, we cannot determine the underlying causes with any certainty. We found mixed support for the concealed breeding strategy, females derived no benefit from nesting in areas with more willow (Salix spp.; measure of concealment) except that the observer effect diminished as willow cover increased. We suggest these patterns are due to conflicting predation pressures. Nest survival was not higher on islands (measure of seclusion) or with increased incubation constancy but was higher post-fox removal, indicating that predator control on breeding grounds could be a viable management option. Nest survival was negatively affected by our nest visitations, most likely by exposing the nest to avian scavengers. We recommend precautions be taken to limit the effects of nest visits in future studies and to consider them as a possible negative bias in estimated nest survival. Future models of the impacts of development within the breeding grounds of king eider should consider the influence of humans in the vicinity of nests.

‘Bee Hotels’ as Tools for Native Pollinator Conservation: A Premature Verdict?

PubMed Central

MacIvor, J. Scott; Packer, Laurence

2015-01-01

Society is increasingly concerned with declining wild bee populations. Although most bees nest in the ground, considerable effort has centered on installing ‘bee hotels’—also known as nest boxes or trap nests—which artificially aggregate nest sites of above ground nesting bees. Campaigns to ‘save the bees’ often promote these devices despite the absence of data indicating they have a positive effect. From a survey of almost 600 bee hotels set up over a period of three years in Toronto, Canada, introduced bees nested at 32.9% of sites and represented 24.6% of more than 27,000 total bees and wasps recorded (47.1% of all bees recorded). Native bees were parasitized more than introduced bees and females of introduced bee species provisioned nests with significantly more female larva each year. Native wasps were significantly more abundant than both native and introduced bees and occupied almost 3/4 of all bee hotels each year; further, introduced wasps were the only group to significantly increase in relative abundance year over year. More research is needed to elucidate the potential pitfalls and benefits of using bee hotels in the conservation and population dynamics of wild native bees. PMID:25785609

Nesting ecology and nest survival of lesser prairie-chickens on the Southern High Plains of Texas

USGS Publications Warehouse

Grisham, Blake A.; Borsdorf, Philip K.; Boal, Clint W.; Boydston, Kathy K.

2014-01-01

The decline in population and range of lesser prairie-chickens (Tympanuchus pallidicinctus) throughout the central and southern Great Plains has raised concerns considering their candidate status under the United States Endangered Species Act. Baseline ecological data for lesser prairie-chickens are limited, especially for the shinnery oak-grassland communities of Texas. This information is imperative because lesser prairie-chickens in shinnery oak grasslands occur at the extreme southwestern edge of their distribution. This geographic region is characterized by hot, arid climates, less fragmentation, and less anthropogenic development than within the remaining core distribution of the species. Thus, large expanses of open rangeland with less anthropogenic development and a climate that is classified as extreme for ground nesting birds may subsequently influence nest ecology, nest survival, and nest site selection differently compared to the rest of the distribution of the species. We investigated the nesting ecology of 50 radio-tagged lesser prairie-chicken hens from 2008 to 2011 in the shinnery oak-grassland communities in west Texas and found a substantial amount of inter-annual variation in incubation start date and percent of females incubating nests. Prairie-chickens were less likely to nest near unimproved roads and utility poles and in areas with more bare ground and litter. In contrast, hens selected areas dominated by grasses and shrubs and close to stock tanks to nest. Candidate models including visual obstruction best explained daily nest survival; a 5% increase in visual obstruction improved nest survival probability by 10%. The model-averaged probability of a nest surviving the incubation period was 0.43 (SE = 0.006; 95% CI: 0.23, 0.56). Our findings indicate that lesser prairie-chicken reproduction during our study period was dynamic and was correlated with seasonal weather patterns that ultimately promoted greater grass growth earlier in the nesting season that provided visual obstruction from predators.

Habitat edges affect patterns of artificial nest predation along a wetland-meadow boundary

NASA Astrophysics Data System (ADS)

Suvorov, Petr; Svobodová, Jana; Albrecht, Tomáš

2014-08-01

Wetland habitats are among the most endangered ecosystems in the world. However, little is known about factors affecting the nesting success of birds in pristine grass-dominated wetlands. During three breeding periods we conducted an experiment with artificial ground nests to test two basic mechanisms (the matrix and ecotonal effects) that may result in edge effects on nest predation in grass-dominated wetland habitats. Whereas the matrix effect model supposes that predator penetrate from habitat of higher predator density to habitat of lower predator density, thus causing an edge effect in the latter, according to the ecotonal effect model predators preferentially use edge habitats over habitat interiors. In addition, we tested the edge effect in a wetland habitat using artificial shrub nests that simulated the real nests of small open-cup nesting passerines. In our study area, the lowest predation rates on ground nests were found in wetland interiors and were substantially higher along the edges of both wetland and meadow habitat. However, predation was not significantly different between meadow and wetland interiors, indicating that both mechanisms can be responsible for the edge effect in wetland edges. An increased predation rate along wetland edges was also observed for shrub nests, and resembled the predation pattern of real shrub nests in the same study area. Though we are not able to distinguish between the two mechanisms of the edge effect found, our results demonstrate that species nesting in wetland edges bordering arable land may be exposed to higher predation. Therefore, an increase in the size of wetland patches that would lead to a reduced proportion of edge areas might be a suitable management practice to protect wetland bird species in cultural European landscapes.

An ecological process model of female sex offending: the role of victimization, psychological distress, and life stressors.

PubMed

DeCou, Christopher R; Cole, Trevor T; Rowland, Sarah E; Kaplan, Stephanie P; Lynch, Shannon M

2015-06-01

Female sex offenders may be implicated in up to one fifth of all sex crimes committed in the United States. Despite previous research findings that suggest unique patterns of offending among female sex offenders, limited empirical research has investigated the motivations and processes involved. The present study qualitatively examined female sex offenders' offense-related experiences and characterized the internal and external factors that contributed to offending. Semi-structured interviews with 24 female sex offenders were analyzed by a team of coders with limited exposure to the existing literature using grounded theory analysis. A conceptual framework emerged representing distinctive processes for solo- and co-offending, contextualized within ecological layers of social and environmental influence. This model extends previous work by offering an example of nested vulnerabilities proximal to female sexual offending. Implications for future research, prevention, and treatment are discussed. © The Author(s) 2014.

GPS tracking for mapping seabird mortality induced by light pollution.

PubMed

Rodríguez, Airam; Rodríguez, Beneharo; Negro, Juan J

2015-06-02

Light pollution and its consequences on ecosystems are increasing worldwide. Knowledge on the threshold levels of light pollution at which significant ecological impacts emerge and the size of dark refuges to maintain natural nocturnal processes is crucial to mitigate its negative consequences. Seabird fledglings are attracted by artificial lights when they leave their nest at night, causing high mortality. We used GPS data-loggers to track the flights of Cory's shearwater Calonectris diomedea fledglings from nest-burrows to ground, and to evaluate the light pollution levels of overflown areas on Tenerife, Canary Islands, using nocturnal, high-resolution satellite imagery. Birds were grounded at locations closer than 16 km from colonies in their maiden flights, and 50% were rescued within a 3 km radius from the nest-site. Most birds left the nests in the first three hours after sunset. Rescue locations showed radiance values greater than colonies, and flight distance was positively related to light pollution levels. Breeding habitat alteration by light pollution was more severe for inland colonies. We provide scientific-based information to manage dark refuges facilitating that fledglings from inland colonies reach the sea successfully. We also offer methodological approaches useful for other critically threatened petrel species grounded by light pollution.

Predation of Small Eggs in Artificial Nests: Effects of Nest Position, Edge, and Potential Predator Abundance in Extensive Forest

Treesearch

Richard M. DeGraaf; Thomas J. Maier; Todd K. Fuller

1999-01-01

After photographtc observations in the field and laboratory tests indicated that small rodents might be significant predators on small eggs, we conducted a field study in central Massachusetts to compare predation of House Sparrow (Passer domesticus) eggs in artificial nests near to (5-15 m) and far from (100-120 m) forest edges and between ground...

Renesting by American woodcocks (Scolopax minor) in Maine

USGS Publications Warehouse

McAuley, D.G.; Longcore, J.R.; Sepik, G.F.

1990-01-01

The American Woodcock (Scolopax minor) is one of the earliest ground-nesting birds in the northeastern United States. In Maine, nesting begins in early April when temperatures can drop below freezing and significant snowfall can accumulate. Nests are usually in open woods, where eggs are laid on the ground in a shallow depression (Pettingill 1936, Mendall and Aldous 1943, Sheldon 1967). Peak hatching occurs in early May (Dwyer et al. 1982), when temperatures are cool and precipitation is common. Woodcock chicks are dependent on the female for most of their food for at least seven days after hatching (Gregg 1984). During cool, wet weather, chicks require constant brooding by females; prolonged periods of inclement weather may lead to substantial mortality of chicks (Dwyer et al. 1988).

Relationships of habitat patch size to predator community and survival of duck nests

USGS Publications Warehouse

Sovada, M.A.; Zicus, M.C.; Greenwood, R.J.; Rave, D.P.; Newton, W.E.; Woodward, R.O.; Beiser, J.A.

2000-01-01

We studied duck nest success and predator community composition in relation to size of discrete patches of nesting cover in the Prairie Pothole Region (PPR) of the United States in 1993-95. We focused on nests in uplands that were seeded to perennial grasses and forbs and enrolled in the Conservation Reserve Program (CRP) in Minnesota, North Dakota, and South Dakota. We estimated daily survival rates (DSRs) of upland duck nests and indices of activity for red foxes (Vulpes vulpes), coyotes (Canis latrans), American badgers (Taxidea taxus), striped skunks (Mephitis mephitis), and Franklin's ground squirrels (Spermophilus franklinii), and related these variables to habitat patch size. The effect of patch size (small vs. large) on estimated annual mean DSR was dependent on date of nest initiation (early vs. late) and year. Examination of within-year comparisons for early and late nests suggested that DSR was generally greater in larger habitat patches. Activity indices for the 5 mammalian nest predators were influenced differently by year, location, and patch size. Activity indices of the red fox were greatest in small patches. Coyote indices were the most inconsistent, demonstrating a year X location X patch size interaction. Activity indices of the striped skunk and American badger varied only among years. Franklin's ground squirrel indices were affected by study area location, with higher indices in the southeast than the northwest. Red fox activity was weakly correlated with that of the striped skunk and coyote. Although a positive relationship between habitat patch size and nest success probably exists, we believe the experiment to fully test this hypothesis will continue to be elusive.

Effects of climate and exurban development on nest predation and predator presence in the southern Appalachian Mountains (USA).

PubMed

Lumpkin, Heather A; Pearson, Scott M; Turner, Monica G

2012-08-01

In the eastern United States, land-use and climate change have likely contributed to declines in the abundance of Neotropical migrant birds that occupy forest interiors, but the mechanisms are not well understood. We conducted a nest-predation experiment in southern Appalachian Mountain forests (North Carolina, U.S.A.) during the 2009 and 2010 breeding seasons to determine the effects of exurban development and temperature on predator presence and the average number of days until eggs in an artificial nest were disturbed by predators. We baited artificial nests with quail (Excalfactoria chinensi) eggs and monitored them for 18 days. We used clay eggs, track plates, and motion-triggered cameras to detect and identify nest predators. The average number of days a nest was undisturbed decreased as mean temperature increased and, to a lesser extent, as the density of buildings increased. Nests on the ground were more often depredated than those in trees, likely due to increased predation by opossum (Didelphis virginiana) and other carnivores. Raccoons (Procyon lotor), opossums, corvids (Corvus brachyrhynchos and Cyanocitta cristata), chipmunks (Tamias striatus), black bears (Ursus americanus), and domestic cats (Felis catus) were the most commonly detected predators. Presence of these predators did not vary as a function of mean temperature. Domestic cats and corvids were detected more frequently in plots with high rather than low densities of buildings. Forest-interior specialists and Neotropical migrants often nest in cool, high-elevation areas with low housing density. These bird species, especially those that nest on the ground, may be most vulnerable to increased nest predation if temperature and exurban development increase at higher elevations as anticipated. ©2012 Society for Conservation Biology.

The Implications of Contamination for Educational Experiments with Two Levels of Nesting

ERIC Educational Resources Information Center

Rhoads, Christopher

2016-01-01

Experimental evaluations that involve the educational system usually involve a hierarchical structure (students are nested within classrooms that are nested within schools, etc.). Concerns about contamination, where research subjects receive certain features of an intervention intended for subjects in a different experimental group, have often led…

Selection indicates preference in diverse habitats: A Ground-Nesting bird (charadrius melodus) using reservoir shoreline

USGS Publications Warehouse

Anteau, M.J.; Sherfy, M.H.; Wiltermuth, M.T.

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006-2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m 2) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

Selection indicates preference in diverse habitats: A ground-nesting bird (Charadrius melodus) using reservoir shoreline

USGS Publications Warehouse

Anteau, Michael J.; Sherfy, Mark H.; Wiltermuth, Mark T.

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006–2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m2) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

Nest suitability, fine-scale population structure and male-mediated dispersal of a solitary ground nesting bee in an urban landscape.

PubMed

López-Uribe, Margarita M; Morreale, Stephen J; Santiago, Christine K; Danforth, Bryan N

2015-01-01

Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei's GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing bee population abundance and connectivity in human dominated habitats and highlights the critical contribution of landscape genetic studies for enhanced conservation and management of native pollinators.

Nest Suitability, Fine-Scale Population Structure and Male-Mediated Dispersal of a Solitary Ground Nesting Bee in an Urban Landscape

PubMed Central

López-Uribe, Margarita M.; Morreale, Stephen J.; Santiago, Christine K.; Danforth, Bryan N.

2015-01-01

Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei’s GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing bee population abundance and connectivity in human dominated habitats and highlights the critical contribution of landscape genetic studies for enhanced conservation and management of native pollinators. PMID:25950429

Selection indicates preference in diverse habitats: a ground-nesting bird (Charadrius melodus) using reservoir shoreline.

PubMed

Anteau, Michael J; Sherfy, Mark H; Wiltermuth, Mark T

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006-2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m(2)) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

Selection Indicates Preference in Diverse Habitats: A Ground-Nesting Bird (Charadrius melodus) Using Reservoir Shoreline

PubMed Central

Anteau, Michael J.; Sherfy, Mark H.; Wiltermuth, Mark T.

2012-01-01

Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006–2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m2) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies. PMID:22299037

Maternal transfer of chlorinated contaminants in the leatherback turtles, Dermochelys coriacea, nesting in French Guiana.

PubMed

Guirlet, Elodie; Das, Krishna; Thomé, Jean-Pierre; Girondot, Marc

2010-04-01

We examined the maternal transfer of organochlorine contaminants (OCs), pesticides (DDTS and HCHs) and polychlorinated biphenyls (PCBs), and the temporal variation of blood and eggs concentrations from 38 leatherback turtles (Dermochelys coriacea) nesting in French Guiana. PCBs were found to be the dominant OCs with respective mean concentrations of 55.14 ng g(-1) lipid-mass for egg and 1.26 ng mL(-1) wet-mass for blood. OC concentrations were lower than concentrations measured in other marine turtles which might be due to the lower trophic position (diet based on gelatinous zooplankton) and to the location of their foraging and nesting grounds. All OCs detected in leatherback blood were detected in eggs, suggesting a maternal transfer of OCs. This transfer was shown to depend on female blood concentration for SigmaDDTs and for the most prevalent PCB congeners, since significant relationships were found between paired blood-egg concentrations. During the nesting season, OC concentrations in eggs and the percentage of lipid in eggs were found to decline in successive clutches, highlighting a process of offloading from females to their eggs and a decreasing investment of lipid from females into their clutches. OCs in eggs tended to be higher in females spending 3 years in the foraging grounds between two nesting seasons than in those spending 2 years, suggesting an impact of time spacing two breeding seasons, called remigration interval, and of location of the foraging grounds. 2010 Elsevier Ltd. All rights reserved.

Nesting habits shape feeding preferences and predatory behavior in an ant genus

NASA Astrophysics Data System (ADS)

Dejean, Alain; Labrière, Nicolas; Touchard, Axel; Petitclerc, Frédéric; Roux, Olivier

2014-04-01

We tested if nesting habits influence ant feeding preferences and predatory behavior in the monophyletic genus Pseudomyrmex (Pseudomyrmecinae) which comprises terrestrial and arboreal species, and, among the latter, plant-ants which are obligate inhabitants of myrmecophytes (i.e., plants sheltering so-called plant-ants in hollow structures). A cafeteria experiment revealed that the diet of ground-nesting Pseudomyrmex consists mostly of prey and that of arboreal species consists mostly of sugary substances, whereas the plant-ants discarded all the food we provided. Workers forage solitarily, detecting prey from a distance thanks to their hypertrophied eyes. Approach is followed by antennal contact, seizure, and the manipulation of the prey to sting it under its thorax (next to the ventral nerve cord). Arboreal species were not more efficient at capturing prey than were ground-nesting species. A large worker size favors prey capture. Workers from ground- and arboreal-nesting species show several uncommon behavioral traits, each known in different ant genera from different subfamilies: leaping abilities, the use of surface tension strengths to transport liquids, short-range recruitment followed by conflicts between nestmates, the consumption of the prey's hemolymph, and the retrieval of entire prey or pieces of prey after having cut it up. Yet, we never noted group ambushing. We also confirmed that Pseudomyrmex plant-ants live in a kind of food autarky as they feed only on rewards produced by their host myrmecophyte, or on honeydew produced by the hemipterans they attend and possibly on the fungi they cultivate.

Sporadic nesting reveals long distance colonisation in the philopatric loggerhead sea turtle (Caretta caretta).

PubMed

Carreras, Carlos; Pascual, Marta; Tomás, Jesús; Marco, Adolfo; Hochscheid, Sandra; Castillo, Juan José; Gozalbes, Patricia; Parga, Mariluz; Piovano, Susanna; Cardona, Luis

2018-01-23

The colonisation of new suitable habitats is crucial for species survival at evolutionary scale under changing environmental conditions. However, colonisation potential may be limited by philopatry that facilitates exploiting successful habitats across generations. We examine the mechanisms of long distance dispersal of the philopatric loggerhead sea turtle (Caretta caretta) by analysing 40 sporadic nesting events in the western Mediterranean. The analysis of a fragment of the mitochondrial DNA and 7 microsatellites of 121 samples from 18 of these nesting events revealed that these nests were colonising events associated with juveniles from distant populations feeding in nearby foraging grounds. Considering the temperature-dependent sex determination of the species, we simulated the effect of the incubation temperature and propagule pressure on a potential colonisation scenario. Our results indicated that colonisation will succeed if warm temperature conditions, already existing in some of the beaches in the area, extend to the whole western Mediterranean. We hypothesize that the sporadic nesting events in developmental foraging grounds may be a mechanism to overcome philopatry limitations thus increasing the dispersal capabilities of the species and the adaptability to changing environments. Sporadic nesting in the western Mediterranean can be viewed as potential new populations in a scenario of rising temperatures.

Snowpack and variation in reproductive ecology of a montane ground-nesting passerine, Junco hyemalis

USGS Publications Warehouse

Smith, Kimberly G.; Andersen, Douglas C.

1985-01-01

Effects of snow depth and rate of snowmelt on reproduction of a montane ground-nesting passerine were examined in a 5-year study of Dark-eyed Juncos Junco hyemalis in northern Utah, USA. Distribution of clucth sizes differed significantly among years. Although most clutches contained four eggs, 3-egg clutches, due primarily to second nestings, were more common during a year of early snowmelt and 5-egg clutches were most common during two years of late snowmelt. Average clutch size was lowest in an early snowmelt year and average clutch size and date at which meadows became snow-free were significantly positively correlated. Average hatching date of 4-egg clutches was also significantly positively correlated with date at which meadows became snow-free demonstrating that most birds tracked the pattern of snowmelt. Early snowmelt may allow more pairs to attempt second nesting, but late-lying snow causes breeding to be delayed, allowing time for only one nesting attempt. During this delay, female juncos continue to feed and some may gain enough reserves to produce larger clutches, accounting for the increase in average clutch size in years of late snowmelt. Three female juncos examined in June 1982, a period of late snowmelt, had significantly more lipid reserves than did six males collected at the same time, suggesting that females are not physiologically stressed while awaiting snowmelt. By tracking snowmelt patterns, juncos synchronize production of young with peak summer insect abundance and potentially decrease risk of predation. Snow depth and rate of snowmelt are thus proximate environmental factors that may influence the reproductive ecology of ground-nesting passerines.

The Foraging Tunnel System of the Namibian Desert Termite, Baucaliotermes hainesi

PubMed Central

Tschinkel, Walter R.

2010-01-01

The harvester termite, Baucaliotermes hainesi (Fuller) (Termitidae: Nasutitermitinae), is an endemic in southern Namibia, where it collects and eats dry grass. At the eastern, landward edge of the Namib Desert, the nests of these termites are sometimes visible above ground surface, and extend at least 60 cm below ground. The termites gain access to foraging areas through underground foraging tunnels that emanate from the nest. The looseness of the desert sand, combined with the hardness of the cemented sand tunnels allowed the use of a gasolinepowered blower and soft brushes to expose tunnels lying 5 to 15 cm below the surface. The tunnels form a complex system that radiates at least 10 to 15 m from the nest with crossconnections between major tunnels. At 50 to 75 cm intervals, the tunnels are connected to the surface by vertical risers that can be opened to gain foraging access to the surrounding area. Foraging termites rarely need to travel more than a meter on the ground surface. The tunnels swoop up and down forming high points at riser locations, and they have a complex architecture. In the center runs a smooth, raised walkway along which termites travel, and along the sides lie pockets that act as depots where foragers deposit grass pieces harvested from the surface. Presumably, these pieces are transported to the nest by a second group of termites. There are also several structures that seem to act as vertical highways to greater depths, possibly even to moist soil. A census of a single nest revealed about 45,000 termites, of which 71% were workers, 9% soldiers and 6% neotenic supplementary reproductives. The nest consisted of a hard outer “carapace” of cemented sand, with a central living space of smooth, sweeping arches and surfaces. A second species of termite, Promirotermes sp. nested in the outer carapace. PMID:20672982

Reproductive ecology of Dusky Flycatchers in western Montana

USGS Publications Warehouse

Sedgwick, James A.

1993-01-01

Breeding ecology of Dusky Flycatchers (Empidonax oberholseri) was studied in western Montana from May-August 1974. Dusky Flycatchers were monogamous and single-brooded although some pairs made renesting attempts after first nests failed. Length of the reproductive cycle for first nesting attempts, from arrival on the breeding grounds to fledging, was about 70 days. All nests were placed in shrubs, primarily ninebark (Physocarpus malvaceus) and Rocky Mountain maple (Acer glabrum), and were an average of 150 cm above the ground. Females incubated a clutch with an average of 4.0 eggs for 15-16 days, and the average nestling period was 17.5 days. Both sexes fed nestlings and fledglings, but only females brooded nestlings. Egg survival was 63.8%, hatching success was 95.4%, and nestling survival was 61.9% for an overall probability of 0.376 percent that an egg produced a fledgling. Predation was the major cause of nest failure. Dusky Flycatchers reared an average of 1.9 fledglings/pair.

GPS tracking for mapping seabird mortality induced by light pollution

PubMed Central

Rodríguez, Airam; Rodríguez, Beneharo; Negro, Juan J.

2015-01-01

Light pollution and its consequences on ecosystems are increasing worldwide. Knowledge on the threshold levels of light pollution at which significant ecological impacts emerge and the size of dark refuges to maintain natural nocturnal processes is crucial to mitigate its negative consequences. Seabird fledglings are attracted by artificial lights when they leave their nest at night, causing high mortality. We used GPS data-loggers to track the flights of Cory’s shearwater Calonectris diomedea fledglings from nest-burrows to ground, and to evaluate the light pollution levels of overflown areas on Tenerife, Canary Islands, using nocturnal, high-resolution satellite imagery. Birds were grounded at locations closer than 16 km from colonies in their maiden flights, and 50% were rescued within a 3 km radius from the nest-site. Most birds left the nests in the first three hours after sunset. Rescue locations showed radiance values greater than colonies, and flight distance was positively related to light pollution levels. Breeding habitat alteration by light pollution was more severe for inland colonies. We provide scientific-based information to manage dark refuges facilitating that fledglings from inland colonies reach the sea successfully. We also offer methodological approaches useful for other critically threatened petrel species grounded by light pollution. PMID:26035530

Observer visitation frequency and success of mourning dove nests: A field experiment

USGS Publications Warehouse

Nichols, J.D.; Percival, H.F.; Coon, R.A.; Conroy, M.J.; Hensler, G.L.; Hines, J.E.

1984-01-01

Field studies of nesting success generally require visits by the investigator to the nests under study. Such visits may themselves influence nesting success, however, and this possibility has been discussed and investigated by a number of workers with a variety of bird species. Livezey (1980) reviewed the relevant literature for duck nests and noted that most studies failed to demonstrate differences in nesting success between visited nests and those not visited. Livezey (1980) found in his own work that nest abandonment may have occurred as a result of disturbance by observers but that nest predation was not related to time spent by observers at nests or number of observers approaching nests. Various components of nesting and breeding success in seabirds are thought to be adversely affected by human disturbance and nest visitation (Gillett et al. 1975, Robert and Ralph 1975, Ollason and Dunnet 1980). Upland, ground-nesting species have also been studied (e.g. Stoddard 1931, Evans and Wolfe 1967, Henry 1969, Roseberry and Klimstra 1970, Klimstra and Roseberry 1975), and, although conclusions have varied, a number of these workers found no effect of observers on nest-predation rates.

Do mammalian nest predators follow human scent trails in the shortgrass prairie?

USGS Publications Warehouse

Skagen, S.K.; Stanley, T.R.; Dillon, M.B.

1999-01-01

Nest predation, the major cause of nest failure in passerines, has exerted a strong influence on the evolution of life history traits of birds. Because human disturbance during nest monitoring may alter predation rates, we investigated whether human scent affected the survival of artificial ground nests in shortgrass prairie. Our experiment consisted of two treatments, one in which there was no attempt to mask human scent along travel routes between artificial nests, and one in which we masked human scent with cow manure, a scent familiar to mammalian predators in the study area. We found no evidence that human scent influenced predation rates, nor that mammalian predators followed human trails between nests. We conclude that scent trails made by investigators do not result in lower nesting success of passerines of the shortgrass prairie where vegetation trampling is minimal, mammalian predators predominate, and avian predators are rare.

Predation and nutrients drive population declines in breeding waders.

PubMed

Møller, Anders Pape; Thorup, Ole; Laursen, Karsten

2018-04-20

Allee effects are defined as a decline in per capita fitness at low population density. We hypothesized that predation reduces population size of breeding waders and thereby the efficiency of predator deterrence, while total nitrogen through its effects on primary and secondary productivity increases population size. Therefore, nest predation could have negative consequences for population size because nest failure generally results in breeding dispersal and hence reduced local population density. To test these predictions, we recorded nest predation in five species of waders for 4,745 nests during 1987-2015 at the nature reserve Tipperne, Denmark. Predation rates were generally negatively related to conspecific and heterospecific population density, but positively related to overall population density of the entire wader community. Nest predation and population density were related to ground water level, management (grazing and mowing), and nutrients. High nest predation with a time lag of one year resulted in low overall breeding population density, while high nutrient levels resulted in higher population density. These two factors accounted for 86% of the variance in population size, presumably due to effects of nest predation on emigration, while nutrient levels increased the level of vegetation cover and the abundance of food in the surrounding brackish water. These findings are consistent with the hypothesis that predation may reduce population density through negative density dependence, while total nitrogen at adjacent shallow water may increase population size. Nest predation rates were reduced by high ground water level in March, grazing by cattle and mowing that affected access to and susceptibility of nests to predators. These effects can be managed to benefit breeding waders. © 2018 by the Ecological Society of America.

Chemical analyses of ground-water samples from the Rio Grande Valley in the vicinity of Albuquerque, New Mexico, October 1993 through January 1994

USGS Publications Warehouse

Wilkins, D.W.; Schlottmann, J.L.; Ferree, D.M.

1996-01-01

A study was conducted to investigate general ground-water- quality conditions and contaminant locations in the Rio Grande Valley in the vicinity of Albuquerque, New Mexico. Water samples from 36 observation wells in 12 well nests were analyzed. The well nests are located along three roads near the Rio Grande--two well nests near Paseo del Norte, five well nests near Monta?o Road, and five well nests near Rio Bravo Boulevard. The water samples were collected from October 19, 1993, through January 18, 1994. Water-quality types by major-ion composition were calcium bicarbonate (found in most samples), sodium sulfate, calcium sulfate, and calcium sulfate chloride. Nutrients were detected in all but one sample. Ammonia was detected in 34 samples, nitrite in 4 samples, and nitrate in 17 samples. Orthophosphate was detected in 31 samples. Organic carbon was detected in all samples collected. The trace elements arsenic and barium were detected in all samples and zinc in 31 samples. Fourteen samples contained detectable copper. Cadmium was detected in one sample, chromium in two samples, lead in four samples, and selenium in two samples. Mercury and silver were not detected.

An Evaluation of the Hoʻouna Pono Curriculum: A Pilot Study of Culturally Grounded Substance Abuse Prevention for Rural Hawaiian Youth

PubMed Central

Okamoto, Scott K.; Kulis, Stephen; Helm, Susana; Lauricella, Michela; Valdez, Jessica K.

2016-01-01

This pilot study evaluated the Hoʻouna Pono curriculum, which is a culturally grounded, school-based, drug prevention curriculum tailored to rural Native Hawaiian youth. The curriculum focuses on culturally relevant drug resistance skills training and is aligned with the State of Hawaiʻi academic standards. Six Hawaiʻi Island public middle/intermediate schools randomly assigned to intervention or treatment-as-usual comparison conditions (N = 213) were evaluated in this study. Paired sample t-tests separating intervention and comparison groups were conducted, as well as mixed models that adjusted for random effects (nesting) at the school level. Findings suggested that the curriculum was effective in maintaining youths’ use of culturally relevant drug resistance skills, as well as decreasing girls’ aggressive behaviors, at six-month follow up. Unanticipated findings also suggested areas for curricular improvement, including more emphasis on normative drug education. Implications for future research and development of the curriculum are discussed. PMID:27180710

A comparison of burn season effects on nesting birds in North Dakota mixed-grass prairie

USGS Publications Warehouse

Higgins, K.F.

1986-01-01

During 1982-1985, the effects of single spring and fall burn treatments on ground nesting birds and residual cover were studied on five paired areas of native mixed-grass prairie in northwestern Stutsman County, ND. Annually, visual obstruction readings to index the height-density of residual cover were taken once and nest searches were made four times on each area. Residual nesting cover on fall burn plots averaged taller and denser than on spring burn plots during post-fire growing years 2-4. A total of 259 duck nests and 63 nests of non-passerine birds were found during the four years. Duck nesting success was significantly greater (P < 0.05) in fall burn plots than in spring burn plots for all species and years combined. Too few nests of other bird species were found for valid comparisons. Results suggest that vegetation structure and duck nesting response to spring and fall burns became similar again by the third post-fire growing season.

Food habits of nesting prairie falcons in Campbell County

Treesearch

John R. Squires; Stanley H. Anderson; Robert Oakleaf

1989-01-01

Fifteen species of prey were utilized by nesting Prairie Falcons (Falco mexicanus) as determined through pellet analysis. Thirteen-lined Ground Squirrels (Spermophilus tridecemlineatus), the most common prey, were present in 91% of the pellets, followed by Western Meadowlarks (Sturnella neglecta) which were present in 56% of pellets. Horned Larks (Eremophila...

KSC-03pd0948

NASA Image and Video Library

2003-04-02

KENNEDY SPACE CENTER, FLA. -- A pair of nesting ospreys now occupy a nest recently constructed on a speaker in the lower parking lot of the Press Site. Eggs have been sighted in the nest. The NASA logo seen in the background is on the nearby Vehicle Assembly Building. Known as a fish hawk, the osprey selects sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States it is found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

KSC-03pd0951

NASA Image and Video Library

2003-04-02

KENNEDY SPACE CENTER, FLA. -- A pair of nesting ospreys now occupy a nest recently constructed on a speaker in the lower parking lot of the Press Site. Eggs have been sighted in the nest. The NASA logo seen in the background is on the nearby Vehicle Assembly Building. Known as a fish hawk, the osprey selects sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States it is found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

BIOLOGICAL REVIEW OF THE VEGETATION REMOVAL ON 218-W-6, 200 West Area, ECR No.2002-200-031

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sackschewsky, Michael R.

2003-06-26

Vegetation will be mechanically removed from the 218-W-6 Low Level Burial Ground (LLBG). The 218-W-6 LLBG consists of shrub-steppe and herbaceous habitats. The Western meadowlark, killdeer, lark sparrow, and loggerhead shrike could nest in the project area, based on known nesting preferences. We recommend that vegetation removal on 218-W-6 occur outside the nesting season (i.e., August 1 through February 28), in order to avoid potential adverse impacts to nesting individuals and/or their young and to comply with the Migratory Bird Treaty Act.

KSC-04pd1215

NASA Image and Video Library

2004-05-18

KENNEDY SPACE CENTER, FLA. -- One of two fledgling ospreys still in the nest stretches its wings to fly away. The stick-built nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-1215

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One of two fledgling ospreys still in the nest stretches its wings to fly away. The stick-built nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

Ground roost resource selection for Merriam's wild turkeys

Treesearch

Chad P. Lehman; Daniel J. Thompson; Mark A. Rumble

2010-01-01

Concealment cover is important for ground-roosting wild turkey (Meleagris gallopavo) poults immediately following hatch during the vulnerable, preflight stage. We compared concealment cover resources selected at ground roosts to those of nest sites and available resources for Merriam's turkeys (Meleagris gallopavo merriami) in the Black Hills of South Dakota, USA...

Population trends and survival of nesting green sea turtles Chelonia mydas on Aves Island, Venezuela

USGS Publications Warehouse

Garcia-Cruz, Marco A.; Lampo, Margarita; Peñaloza, Claudia L.; Kendall, William L.; Solé, Genaro; Rodriguez-Clark, Kathryn M.

2015-01-01

Long-term demographic data are valuable for assessing the effect of anthropogenic impacts on endangered species and evaluating recovery programs. Using a 2-state open robust design model, we analyzed mark-recapture data from green turtles Chelonia mydas sighted between 1979 and 2009 on Aves Island, Venezuela, a rookery heavily impacted by human activities before it was declared a wildlife refuge in 1972. Based on the encounter histories of 7689 nesting females, we estimated the abundance, annual survival, and remigration intervals for this population. Female survival varied from 0.14-0.91, with a mean of 0.79, which is low compared to survival of other populations from the Caribbean (mean = 0.84) and Australia (mean = 0.95), even though we partially corrected for tag loss, which is known to negatively bias survival estimates. This supports prior suggestions that Caribbean populations in general, and the Aves Island population in particular, may be more strongly impacted than populations elsewhere. It is likely that nesters from this rookery are extracted while foraging in remote feeding grounds where hunting still occurs. Despite its relatively low survival, the nesting population at Aves Island increased during the past 30 years from approx. 500 to >1000 nesting females in 2009. Thus, this population, like others in the Caribbean and the Atlantic, seems to be slowly recovering following protective management. Although these findings support the importance of long-term conservation programs aimed at protecting nesting grounds, they also highlight the need to extend management actions to foraging grounds where human activities may still impact green turtle populations.

Does increasing daylength control seasonal changes in clutch sizes of Northern Pintails (Anas acuta)?

USGS Publications Warehouse

Krapu, G.L.; Sargeant, G.A.; Perkins, A.E.H.

2002-01-01

We evaluated spatiotemporal variation in clutch sizes of Northern Pintails (pintails; Anas acuta) nesting in California (1985 to 1996), North Dakota (1982 to 1985), Saskatchewan (1982 to 1985) and Alaska (1991 to 1993) to determine whether seasonal declines in clutch size varied in ways that were consistent with a controlling influence of increasing day length. Pintails began nesting in mid-March in California, mid-April in North Dakota and Saskatchewan, and mid-May in Alaska. Observed durations of nesting were 70 ± 2.6 days (SE) in California, 60 ± 6.3 days in North Dakota, 66 ± 1.3 days in Saskatchewan, and 42 ± 0.7 days in Alaska. Annual differences were the principal source of variation in mean clutch sizes (σ̂Y2 = 0.15, SE = 0.049), which varied little among study locations (σ̂A2 = 0.002, SE = 0.013). Predicted rates of seasonal decline in clutch sizes increased with latitude early in the nesting season, but declined as the nesting season progressed, except in California. Rates of decline in clutch sizes thus were not directly related to rates of increase in day length. Predicted declines in numbers of eggs per clutch over the nesting season were similar for all four locations (range, 3.05–3.12) despite wide variation in durations of nesting. Evidence suggests that reduced nutrient availability during nesting contributes to a higher rate of decline in clutch sizes in Alaska than in temperate regions. Pintails that nest early lay large initial clutches, but thereafter clutch sizes decline rapidly and breeding terminates early. This reproductive strategy is adaptive because young that hatch earliest exhibit the highest survival rates; however, the conversion of grassland to cropland on the primary prairie breeding grounds has reduced hatching rates of clutches laid early in the nesting season. Under these conditions, the limited capacity to renest in late spring on their prairie breeding grounds probably has contributed to Pintail population declines.

Distorting Gene Pools by Conservation: Assessing the Case of Doomed Turtle Eggs

NASA Astrophysics Data System (ADS)

Mrosovsky, N.

2006-10-01

Sea turtles have a high reproductive output and high mortality at early stages of the life cycle. In particular, many nests are laid below or close to high tide lines, and subsequently large numbers of eggs may be inundated and destroyed. A common conservation procedure is to relocate such doomed eggs to higher ground. This article examines this practice in the light of recent data revealing that some individual turtles tend to nest relatively near the water and others relatively higher up the beach. Discussion is focused on the question of why apparently poor placement of nests has not been selected against. Comparison between the ecology of leatherback and hawksbill turtle nesting beaches suggests that predictability of environmental conditions on the nesting beaches has an important influence on patterns of nest-site selection. Options are outlined for the management of nesting beaches where a high proportion of turtle eggs is subject to destruction by flooding.

Distorting gene pools by conservation: Assessing the case of doomed turtle eggs.

PubMed

Mrosovsky, N

2006-10-01

Sea turtles have a high reproductive output and high mortality at early stages of the life cycle. In particular, many nests are laid below or close to high tide lines, and subsequently large numbers of eggs may be inundated and destroyed. A common conservation procedure is to relocate such doomed eggs to higher ground. This article examines this practice in the light of recent data revealing that some individual turtles tend to nest relatively near the water and others relatively higher up the beach. Discussion is focused on the question of why apparently poor placement of nests has not been selected against. Comparison between the ecology of leatherback and hawksbill turtle nesting beaches suggests that predictability of environmental conditions on the nesting beaches has an important influence on patterns of nest-site selection. Options are outlined for the management of nesting beaches where a high proportion of turtle eggs is subject to destruction by flooding.

Breeding biology of the pileated woodpecker—management implications.

Treesearch

Evelyn L. Bull; E. Charles. Meslow

1988-01-01

We located and studied 123 pileated woodpecker (Dryocopus pileatus) nests from 1973 to 1983 in northeastern Oregon. Pileated woodpeckers excavated nest cavities in late March and early April, incubated eggs as early as 13 May and as late as 15 June, and fledged young between 26 June and 13 July. These birds nested at 1 year of age, and some lived...

Nest predation of Abert's Towhees by coachwhips and roadrunners

Treesearch

Deborah M. Finch

1981-01-01

Predation by snakes has been implicated as a major cause of high nesting mortality in many passerine birds (e.g., Willis 1972, Best 1978, Nolan 1978), but predation is rarely observed (e.g., Snow 1962, Lill 1974). Snakes and other predators typically consume the entire contents of a nest during one visit (e.g., Nolan 1978). Nestling starvation caused by sibling...

Sunflower (Helianthus annuus) pollination in California's Central Valley is limited by native bee nest site location.

PubMed

Sardiñas, Hillary S; Tom, Kathleen; Ponisio, Lauren Catherine; Rominger, Andrew; Kremen, Claire

2016-03-01

The delivery of ecosystem services by mobile organisms depends on the distribution of those organisms, which is, in turn, affected by resources at local and landscape scales. Pollinator-dependent crops rely on mobile animals like bees for crop production, and the spatial relationship between floral resources and nest location for these central-place foragers influences the delivery of pollination services. Current models that map pollination coverage in agricultural regions utilize landscape-level estimates of floral availability and nesting incidence inferred from expert opinion, rather than direct assessments. Foraging distance is often derived from proxies of bee body size, rather than direct measurements of foraging that account for behavioral responses to floral resource type and distribution. The lack of direct measurements of nesting incidence and foraging distances may lead to inaccurate mapping of pollination services. We examined the role of local-scale floral resource presence from hedgerow plantings on nest incidence of ground-nesting bees in field margins and within monoculture, conventionally managed sunflower fields in California's Central Valley. We tracked bee movement into fields using fluorescent powder. We then used these data to simulate the distribution of pollination services within a crop field. Contrary to expert opinion, we found that ground-nesting native bees nested both in fields and edges, though nesting rates declined with distance into field. Further, we detected no effect of field-margin floral enhancements on nesting. We found evidence of an exponential decay rate of bee movement into fields, indicating that foraging predominantly occurred in less than 1% of medium-sized bees' predicted typical foraging range. Although we found native bees nesting within agricultural fields, their restricted foraging movements likely centralize pollination near nest sites. Our data thus predict a heterogeneous distribution of pollination services within sunflower fields, with edges receiving higher coverage than field centers. To generate more accurate maps of services, we advocate directly measuring the autecology of ecosystem service providers, which vary by crop system, pollinator species, and region. Improving estimates of the factors affecting pollinator populations can increase the accuracy of pollination service maps and help clarify the influence of farming practices on wild bees occurring in agricultural landscapes.

Stabilities of ant nests and their adjacent soils

NASA Astrophysics Data System (ADS)

Echezona, B. C.; Igwe, C. A.

2012-10-01

Nests habour ants and termites and protect them from harsh environmental conditions. The structural stabilities of nests were studied to ascertain their relative vulnerability to environmental stresses. Arboreal-ant nests were pried from different trees, while epigeous-termite nests were excavated from soil surface within the sample area. Soils without any visible sign of ant or termite activity were also sampled 6 m away from the nests as control. Laboratory analysis result showed that irrespective of the tree hosts, the aggregate stabilities of the ant nests were lower than those of the ground termite, with nests formed on Cola nitida significantly showing lower aggregate stability (19.7%) than other antnest structures. Clay dispersion ratio, moisture content, water stable aggregate class <0.25mm and sand mass were each negatively correlated with aggregate stability, while water stable aggregate class1.00-0.50 mm gave a positive correlation. Nest structures were dominated more by water stable aggregate class >2.00 mm but path analysis demonstrated that water stable aggregate class <0.25 mm contributed most to the higher aggregate stability of the termite nest than the other nest. Nest aggregates had greater structural stability compared to the control soil. The higher structural stability of termite nests over other nest and soil was considered a better adaptive mechanism against body desiccation.

Long-term lesser prairie-chicken nest ecology in response to grassland management

USGS Publications Warehouse

Fritts, Sarah R.; Grisham, Blake A.; Haukos, David A.; Boal, Clint W.; Patten, Michael; Wolfe, Don H.; Dixon, Charles; Cox, Robert D.; Heck, Willard R.

2016-01-01

Long-term population and range declines from habitat loss and fragmentation caused the lesser prairie-chicken (Tympanuchus pallidicinctus) to be a species of concern throughout its range. Current lesser prairie-chicken range in New Mexico and Texas is partially restricted to sand shinnery oak (Quercus havardii; hereafter shinnery oak) prairies, on which cattle grazing is the main socioeconomic driver for private landowners. Cattle producers within shinnery oak prairies often focus land management on shrub eradication using the herbicide tebuthiuron to promote grass production for forage; however, herbicide application alone, and in combination with grazing, may affect nest site selection and nest survival of lesser prairie-chickens through the reduction of shinnery oak and native grasses. We used a controlled, paired, completely randomized design study to assess the influence of grazing and tebuthiuron application and their combined use on nest site selection and nest survival from 2001 to 2010 in Roosevelt County, New Mexico, USA at 2 spatial scales (i.e., treatment and microhabitat) in 4 treatments: tebuthiuron with grazing, tebuthiuron without grazing, no tebuthiuron with grazing, and a control of no tebuthiuron and no grazing. Grazing treatment was a short-duration system in which plots were grazed once during the dormant season and once during the growing season. Stocking rate was calculated each season based on measured forage production and applied to remove ≤25% of available herbaceous material per season. At the treatment scale, we compared nest site selection among treatments using 1-way χ2 tests and nest survival among treatments using a priori candidate nest survival models in Program MARK. At the microhabitat scale, we identified important habitat predictors of nest site selection and nest survival using logistic regression and a priori candidate nest survival models in Program MARK, respectively. Females typically used treatments as expected and we did not detect trends in selection. Nest survival did not differ among treatments. At the microhabitat scale, nest sites had less bare ground (P = 0.001) and greater angles of obstruction (P ≤ 0.001) compared to random sites. There was a high degree of model selection uncertainty among our candidate models at the microhabitat scale and survival estimates were similar among habitat covariates. Results suggest a tebuthiuron application rate of 0.60 kg/ha, short-duration grazing, and a combination of these management techniques were not detrimental to lesser prairie-chicken nest site selection or nest survival. However, intensified management that increases bare ground or reduces overhead cover may negatively affect lesser prairie-chicken nesting habitat and nest survival.

Comparison and assessment of aerial and ground estimates of waterbird colonies

USGS Publications Warehouse

Green, M.C.; Luent, M.C.; Michot, T.C.; Jeske, C.W.; Leberg, P.L.

2008-01-01

Aerial surveys are often used to quantify sizes of waterbird colonies; however, these surveys would benefit from a better understanding of associated biases. We compared estimates of breeding pairs of waterbirds, in colonies across southern Louisiana, USA, made from the ground, fixed-wing aircraft, and a helicopter. We used a marked-subsample method for ground-counting colonies to obtain estimates of error and visibility bias. We made comparisons over 2 sampling periods: 1) surveys conducted on the same colonies using all 3 methods during 3-11 May 2005 and 2) an expanded fixed-wing and ground-survey comparison conducted over 4 periods (May and Jun, 2004-2005). Estimates from fixed-wing aircraft were approximately 65% higher than those from ground counts for overall estimated number of breeding pairs and for both dark and white-plumaged species. The coefficient of determination between estimates based on ground and fixed-wing aircraft was ???0.40 for most species, and based on the assumption that estimates from the ground were closer to the true count, fixed-wing aerial surveys appeared to overestimate numbers of nesting birds of some species; this bias often increased with the size of the colony. Unlike estimates from fixed-wing aircraft, numbers of nesting pairs made from ground and helicopter surveys were very similar for all species we observed. Ground counts by one observer resulted in underestimated number of breeding pairs by 20% on average. The marked-subsample method provided an estimate of the number of missed nests as well as an estimate of precision. These estimates represent a major advantage of marked-subsample ground counts over aerial methods; however, ground counts are difficult in large or remote colonies. Helicopter surveys and ground counts provide less biased, more precise estimates of breeding pairs than do surveys made from fixed-wing aircraft. We recommend managers employ ground counts using double observers for surveying waterbird colonies when feasible. Fixed-wing aerial surveys may be suitable to determine colony activity and composition of common waterbird species. The most appropriate combination of survey approaches will be based on the need for precise and unbiased estimates, balanced with financial and logistical constraints.

Learning Context When Studying Financial Planning in High Schools: Nesting of Student, Teacher, and Classroom Characteristics

ERIC Educational Resources Information Center

Danes, Sharon M.; Rodriguez, Michael C.; Brewton, Katherine E.

2013-01-01

Grounded in social construction theory, the current study investigates the learning context when studying financial planning in high school by analyzing the nesting of student, teacher and classroom characteristics. Key findings were that three student characteristics (initial financial knowledge, gender, senior grade level), one teacher variable…

KSC-04pd1143

NASA Image and Video Library

2004-05-14

KENNEDY SPACE CENTER, FLA. -- - Three osprey fledglings are ready to test their wings from the nest at the NASA News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04PD-1143

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Three osprey fledglings are ready to test their wings from the nest at the NASA News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

Summer bird use of Kansas windbreaks

USGS Publications Warehouse

Cable, T.T.; Schroeder, R.L.; Brack, V.; Cook, P.S.

1992-01-01

Twenty-four windbreaks in Stafford and Pawnee counties in Kansas were censused for birds during the nesting seasons of 1988-1990. Eighty-nine species of birds were found in the windbreaks with 60 species believed to be nesting. Fifteen species used the windbreaks for feeding or as singing perches but did not nest, and 14 species were spring migrants. Species representing 20 taxonomic families and 15 foraging guilds nested in the windbreaks. Fifteen species were members of the omnivore/ground forager guild. Five species considered forest interior or area sensitive were found nesting in the windbreaks. Windbreak area was important in determining which species were present. Windbreaks provide habitat for a large component of the Great Plains' avifauna, including some species whose populations are decreasing in the region.

Colony differences in response to trapping in roseate terns

USGS Publications Warehouse

Burger, J.; Nisbet, I.C.T.; Zingo, James M.; Spendelow, J.A.; Safina, C.; Gochfeld, M.

1995-01-01

Both members of seabird pairs are normally required to fledge young. Seabirds that nest in sites accessible to predators usually have one parent in attendance during the egg/chick phase. Time devoted to foraging can vary with individual skill and age, prey availability and abundance (Seamy 1978), and distance to foraging grounds (Safina 1990). Although average skill of similar-aged individuals should not vary from colony to colony (Ryder 1980), prey availability and abundance, and spatial distribution of foraging grounds may vary. Thus, the percent of time both members of a pair are present at the nest site may vary in different colonies. In this paper, we examine parental behavior in response to trapping in Roseate Terns (Sterna dougallii) nesting in three of the six major colonies in the northeastern United States: Cedar Beach, New York, Falkner Island, Connecticut; and Bird Island, Massachusetts. Roseate Terns were listed on the United States? Endangered Species List in 1987. We were interested in differences among colonies in how often both parents were present, how soon a mate returned to the nest if one parent was temporarily removed, how soon a trapped bird returned to the nest after release, and the time during which the nest was left unguarded. We feel it is important to recognize and make management decisions based on colony differences where they exist. Our study follows directly from earlier work at Cedar Beach on trapping vulnerability of Common Terns (Sterna hirundo) and Roseate Terns. Nisbet reported that Roseate Terns at Bird Island required about three hours to return to the nest after trapping.

Leafcutter bee nests and pupae from the Rancho La Brea Tar Pits of Southern California: implications for understanding the paleoenvironment of the Late Pleistocene.

PubMed

Holden, Anna R; Koch, Jonathan B; Griswold, Terry; Erwin, Diane M; Hall, Justin

2014-01-01

The Rancho La Brea Tar Pits is the world's richest and most important Late Pleistocene fossil locality and best renowned for numerous fossil mammals and birds excavated over the past century. Less researched are insects, even though these specimens frequently serve as the most valuable paleoenvironemental indicators due to their narrow climate restrictions and life cycles. Our goal was to examine fossil material that included insect-plant associations, and thus an even higher potential for significant paleoenviromental data. Micro-CT scans of two exceptionally preserved leafcutter bee nest cells from the Rancho La Brea Tar Pits in Los Angeles, California reveal intact pupae dated between ∼23,000-40,000 radiocarbon years BP. Here identified as best matched to Megachile (Litomegachile) gentilis Cresson (Hymenoptera: Megachilidae) based on environmental niche models as well as morphometrics, the nest cells (LACMRLP 388E) document rare preservation and life-stage. The result of complex plant-insect interactions, they offer new insights into the environment of the Late Pleistocene in southern California. The remarkable preservation of the nest cells suggests they were assembled and nested in the ground where they were excavated. The four different types of dicotyledonous leaves used to construct the cells were likely collected in close proximity to the nest and infer a wooded or riparian habitat with sufficient pollen sources for larval provisions. LACMRLP 388E is the first record of fossil Megachile Latreille cells with pupae. Consequently, it provides a pre-modern age location for a Nearctic group, whose phylogenetic relationships and biogeographic history remain poorly understood. Megachile gentilis appears to respond to climate change as it has expanded its distribution across elevation gradients over time as estimated by habitat suitability comparisons between low and high elevations; it currently inhabits mesic habitats which occurred at a lower elevation during the Last Glacial Maximum ∼21,000 years ago. Nevertheless, the broad ecological niche of M. gentilis appears to have remained stable.

Leafcutter Bee Nests and Pupae from the Rancho La Brea Tar Pits of Southern California: Implications for Understanding the Paleoenvironment of the Late Pleistocene

PubMed Central

Holden, Anna R.; Koch, Jonathan B.; Griswold, Terry; Erwin, Diane M.; Hall, Justin

2014-01-01

The Rancho La Brea Tar Pits is the world’s richest and most important Late Pleistocene fossil locality and best renowned for numerous fossil mammals and birds excavated over the past century. Less researched are insects, even though these specimens frequently serve as the most valuable paleoenvironemental indicators due to their narrow climate restrictions and life cycles. Our goal was to examine fossil material that included insect-plant associations, and thus an even higher potential for significant paleoenviromental data. Micro-CT scans of two exceptionally preserved leafcutter bee nest cells from the Rancho La Brea Tar Pits in Los Angeles, California reveal intact pupae dated between ∼23,000–40,000 radiocarbon years BP. Here identified as best matched to Megachile (Litomegachile) gentilis Cresson (Hymenoptera: Megachilidae) based on environmental niche models as well as morphometrics, the nest cells (LACMRLP 388E) document rare preservation and life-stage. The result of complex plant-insect interactions, they offer new insights into the environment of the Late Pleistocene in southern California. The remarkable preservation of the nest cells suggests they were assembled and nested in the ground where they were excavated. The four different types of dicotyledonous leaves used to construct the cells were likely collected in close proximity to the nest and infer a wooded or riparian habitat with sufficient pollen sources for larval provisions. LACMRLP 388E is the first record of fossil Megachile Latreille cells with pupae. Consequently, it provides a pre-modern age location for a Nearctic group, whose phylogenetic relationships and biogeographic history remain poorly understood. Megachile gentilis appears to respond to climate change as it has expanded its distribution across elevation gradients over time as estimated by habitat suitability comparisons between low and high elevations; it currently inhabits mesic habitats which occurred at a lower elevation during the Last Glacial Maximum ∼21,000 years ago. Nevertheless, the broad ecological niche of M. gentilis appears to have remained stable. PMID:24718701

Estimating populations of nesting brant using aerial videography

USGS Publications Warehouse

Anthony, R. Michael; Anderson, W.H.; Sedinger, J.S.; McDonald, L.L.

1995-01-01

We mounted a video camcorder in a single-engine aircraft to estimate nesting density along 10-m wide strip transects in black brant colonies on the Yukon Delta National Wildlife Refuge, Alaska during 1990-1992. A global positioning system (GPS) receiver was connected to the video recorder and a laptop computer to locate transects and annotate video tape with time and latitude-longitude at 1-second intervals. About 4-5 hours of flight time were required to record 30-40 minutes of video tape needed to survey large (>5,000 nests in > 10 km2)colonies. We conducted ground searches along transects to locate and identify nests for determining detection rates of nests in video images. Counts of nests from video transects were correlated with actual numbers of nests. Resolution of images was sufficient to detect 81% of known nests (with and without incubating females). Of these, 68% were correctly identified as brant nests. The most common misidentification of known nests was failure of viewers to see the nest that the detected bird was incubating. Unattended nests with exposed eggs, down-covered nests, and nesting brant, cackling Canada geese, and emperor geese were identified in video images. Flushing of incubating geese by survey aircraft was not significant. About 10% of known nests were unoccupied in video images compared to 16% unoccupied nests observed from tower blinds during periods without aircraft disturbance.

KSC-03pd0949

NASA Image and Video Library

2003-04-02

KENNEDY SPACE CENTER, FLA. -- A male osprey returns to its nest with a piece of fish in its talons for its mate. The nest was recently constructed on a speaker in the lower parking lot of the Press Site. Eggs have been sighted in the nest. The NASA logo seen in the background is on the nearby Vehicle Assembly Building. Known as a fish hawk, the osprey selects sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

Effects of neonicotinoid insecticide exposure and monofloral diet on nest-founding bumblebee queens.

PubMed

Leza, Mar; Watrous, Kristal M; Bratu, Jade; Woodard, S Hollis

2018-06-13

Bumblebees are among the world's most important groups of pollinating insects in natural and agricultural ecosystems. Each spring, queen bumblebees emerge from overwintering and initiate new nests, which ultimately give rise to workers and new reproductives later in the season. Nest initiation and survival are thus key drivers of both bumblebee pollination services and population dynamics. We performed the first laboratory experiment with the model bumblebee species Bombus impatiens that explores how early nesting success is impacted by the effects of temporary or more sustained exposure to sublethal levels of a neonicotinoid-type insecticide (imidacloprid at 5 ppb in nectar) and by reliance on a monofloral pollen diet, two factors that have been previously implicated in bumblebee decline. We found that queens exhibited increased mortality and dramatically reduced activity levels when exposed to imidacloprid, as well as delayed nest initiation and lower brood numbers in the nest, but partially recovered from these effects when they only received early, temporary exposure. The effects of pollen diet on individual queen- and colony-level responses were overshadowed by effects of the insecticide, although a monofloral pollen diet alone was sufficient to negatively impact brood production. These findings speak to the sensitivity of queen bumblebees during the nest initiation phase of the colony cycle, with implications for how queens and their young nests are uniquely impacted by exposure to threats such as pesticide exposure and foraging habitat unsuitability. © 2018 The Author(s).

Nesting behaviour influences species-specific gas exchange across avian eggshells.

PubMed

Portugal, Steven J; Maurer, Golo; Thomas, Gavin H; Hauber, Mark E; Grim, Tomáš; Cassey, Phillip

2014-09-15

Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (G(H2O)) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell G(H2O) and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in G(H2O) has evolved to maintain optimal water loss across a diverse set of nest environments. We measured gas exchange through eggshell fragments in 151 British breeding bird species and fitted phylogenetically controlled, general linear models to test the relationship between G(H2O) and potential predictor parameters of each species. Of our 17 life-history traits, only two were retained in the final model: wet-incubating parent and nest type. Eggs of species where the parent habitually returned to the nest with wet plumage had significantly higher G(H2O) than those of parents that returned to the nest with dry plumage. Eggs of species nesting in ground burrows, cliffs and arboreal cups had significantly higher G(H2O) than those of species nesting on the ground in open nests or cups, in tree cavities and in shallow arboreal nests. Phylogenetic signal (measured as Pagel's λ) was intermediate in magnitude, suggesting that differences observed in the G(H2O) are dependent upon a combination of shared ancestry and species-specific life history and ecological traits. Although these data are correlational by nature, they are consistent with the hypothesis that parents constrained to return to the nest with wet plumage will increase the humidity of the nest environment, and the eggs of these species have evolved a higher G(H2O) to overcome this constraint and still achieve optimal water loss during incubation. We also suggest that eggs laid in cup nests and burrows may require a higher G(H2O) to overcome the increased humidity as a result from the confined nest microclimate lacking air movements through the nest. Taken together, these comparative data imply that species-specific levels of gas exchange across avian eggshells are variable and evolve in response to ecological and physical variation resulting from parental and nesting behaviours. © 2014. Published by The Company of Biologists Ltd.

Keeping it regular: Development of thermoregulation in four tropical seabird species.

PubMed

Hart, Lorinda A; Downs, Colleen T; Brown, Mark

2017-02-01

The thermoregulatory capacity of a species can determine which climatic niche it occupies. Its development in avian chicks is influenced by numerous factors. Furthermore, it is suggested that altricial chicks develop their thermoregulatory capacity post-hatching, while precocial chicks develop aspects of this in the egg. We investigated the development of thermoregulation of four co-occurring seabird species in the Seychelles; namely white, ground-nesting white-tailed tropicbirds (Phaethon lepturus) and tree-nesting fairy terns (Gygis alba); and dark plumaged, tree-nesting lesser noddies (Anous tenuirostris) and ground- and tree-nesting brown noddies (A. stolidus). White-tailed tropicbirds have semi-altricial chicks, while the remaining species have semi-precocial chicks. Cloacal temperatures (T b ) were measured at five day intervals from newly hatched chicks and compared over time, and with adult T b s. Initial T b s of all chicks, except fairy terns, were lower than those taken when chicks were older. Brooding cessation generally coincided with feather development, as did an increase in T b. Mean chick T b was significantly lower than mean adult T b for all species, but only white-tailed tropicbird and brown noddy chicks in tree nests differed significantly from mean adult T b when chick T b at five day intervals were considered. There was a significant interactive effect of nest site and age on brown noddy chick T b, but chick colour did not have a significant effect on T b . However, brown noddy chicks on dune crests maintained a constant T b sooner than chicks in tree nests. Our results demonstrate that tropical seabird species have a more delayed onset of thermoregulatory capabilities when compared with those in temperate environments, perhaps as nest sites are less thermally challenging. Nest microhabitats and behavioural thermoregulation, are likely more important during early chick development for these species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experimental demonstration of the fitness consequences of an introduced parasite of Darwin's finches.

PubMed

Koop, Jennifer A H; Huber, Sarah K; Laverty, Sean M; Clayton, Dale H

2011-05-11

Introduced parasites are a particular threat to small populations of hosts living on islands because extinction can occur before hosts have a chance to evolve effective defenses. An experimental approach in which parasite abundance is manipulated in the field can be the most informative means of assessing a parasite's impact on the host. The parasitic fly Philornis downsi, recently introduced to the Galápagos Islands, feeds on nestling Darwin's finches and other land birds. Several correlational studies, and one experimental study of mixed species over several years, reported that the flies reduce host fitness. Here we report the results of a larger scale experimental study of a single species at a single site over a single breeding season. We manipulated the abundance of flies in the nests of medium ground finches (Geospiza fortis) and quantified the impact of the parasites on nestling growth and fledging success. We used nylon nest liners to reduce the number of parasites in 24 nests, leaving another 24 nests as controls. A significant reduction in mean parasite abundance led to a significant increase in the number of nests that successfully fledged young. Nestlings in parasite-reduced nests also tended to be larger prior to fledging. Our results confirm that P. downsi has significant negative effects on the fitness of medium ground finches, and they may pose a serious threat to other species of Darwin's finches. These data can help in the design of management plans for controlling P. downsi in Darwin's finch breeding populations.

Individual variation in nest size and nest site features of the Bornean orangutans (Pongo pygmaeus).

PubMed

Rayadin, Yaya; Saitoh, Takashi

2009-05-01

Nest construction is a daily habit of independent orangutans for sleeping or resting. Data on their nests have been used in various ecological studies (e.g., density estimation, ranging behavior, evolution of material culture) because they are the most observable field signs. We investigated nest size and nest site features of Bornean orangutans in the wild during 10 months' fieldwork at three sites in East Kalimantan, Indonesia: Kutai National Park, Birawa, and Meratus. To examine individual variation, we followed 31 individual orangutans and recorded the 92 nests they made for nest size (diameter) and nest site features (height of nest above ground, tree species used for the nest site, the diameter and height of the tree, whether the nest was new or reused, and nest location within the tree). Analyses taking age-sex classes of the focal individuals into consideration showed significant age-sex differences in nest size and location, but not in nest height or nest tree features (diameter, height of tree, and height of lowest branch). Mature orangutans (adult females, unflanged and flanged males) made larger nests than immatures (juveniles and adolescents). Flanged male orangutans with larger nests used stable locations for nesting sites and reused old nests more frequently than immatures. The overall proportion of nests in open (exposed) locations was higher than in closed (sheltered) locations. Flanged males and immatures frequently made open nests, whereas adult females with an infant preferred closed locations. The good correspondence between nest size and age-sex classes indicates that nest size variation may reflect body size and therefore age-sex variation in the population. (c) 2009 Wiley-Liss, Inc.

House Wrens adjust laying dates and clutch size in relation to annual flooding

Treesearch

Deborah M. Finch

1991-01-01

I examined timing of reproduction and productivity in box-nesting House Wrens (Troglodytes aedon) inhabiting three riverbank woodlands subjected to different levels of flooding. In years when the North Platte River flooded its banks submerging ground foraging substrates, dates of nest initiation and egg laying in two wren populations were delayed and nonsynchronized....

Osprey distribution, abundance, and status in western North America: III. The Baja California and Gulf of California population

USGS Publications Warehouse

Henny, C.J.; Anderson, D.W.

1979-01-01

-An estimated 810 ? 55 pairs (minimum estimate) of ospreys (Pandion haliaetus) were nesting in the study area during our survey (24 March-l April 1977). Approximately 174 pairs nested along the Pacific side of Baja California, 255 pairs along the gulf side, 187 pairs on the Midriff Islands, and 194 pairs in coastal Sonora and Sinaloa. Most nested on cliffs adjacent to the sea (59%); some nested on cactus in flat terrain (26%). Seven per cent nested on the ground, three percent nested in mangroves and other trees in the southern portion of the study area,.and four percent nested on man-made structures. The extreme northwestern Baja California population that was extirpated early in this century has not recovered. However, several populations immediately to the south along the Pacific Coast now appear stationary. Pesticide residues in osprey eggs from Mexico were among the lowest reported for the species in North America.

Migrations of Green Turtles (Chelonia mydas) between Nesting and Foraging Grounds across the Coral Sea

PubMed Central

Read, Tyffen C.; Wantiez, Laurent; Werry, Jonathan M.; Farman, Richard; Petro, George; Limpus, Colin J.

2014-01-01

Marine megafauna tend to migrate vast distances, often crossing national borders and pose a significant challenge to managers. This challenge is particularly acute in the Pacific, which contains numerous small island nations and thousands of kilometers of continental margins. The green sea turtle, Chelonia mydas, is one such megafauna that is endangered in Pacific waters due to the overexploitation of eggs and adults for human consumption. Data from long-term tagging programs in Queensland (Australia) and New Caledonia were analysed to investigate the migrations by C. mydas across the Coral Sea between their nesting site and their feeding grounds. A review of data collected over the last 50 years by different projects identified multiple migrations of C. mydas to and from New Caledonia (n = 97) and indicate that turtles foraging in New Caledonia nest in the Great Barrier Reef (Australia) and vice versa. Several explanations exist for turtles exhibiting this energetically costly movement pattern from breeding to distant foraging grounds (1200–2680 km away) despite viable foraging habitat being available in the local vicinity. These include hatchling drift, oceanic movements and food abundance predictability. Most of the tag recoveries in New Caledonia belonged to females from the south Great Barrier Reef genetic stock. Some females (n = 2) even showed fidelity to foraging sites located 1200 km away from the nesting site located in New Caledonia. This study also reveals previously unknown migrations pathways of turtles within the Coral Sea. PMID:24940598

Migrations of green turtles (Chelonia mydas) between nesting and foraging grounds across the Coral Sea.

PubMed

Read, Tyffen C; Wantiez, Laurent; Werry, Jonathan M; Farman, Richard; Petro, George; Limpus, Colin J

2014-01-01

Marine megafauna tend to migrate vast distances, often crossing national borders and pose a significant challenge to managers. This challenge is particularly acute in the Pacific, which contains numerous small island nations and thousands of kilometers of continental margins. The green sea turtle, Chelonia mydas, is one such megafauna that is endangered in Pacific waters due to the overexploitation of eggs and adults for human consumption. Data from long-term tagging programs in Queensland (Australia) and New Caledonia were analysed to investigate the migrations by C. mydas across the Coral Sea between their nesting site and their feeding grounds. A review of data collected over the last 50 years by different projects identified multiple migrations of C. mydas to and from New Caledonia (n = 97) and indicate that turtles foraging in New Caledonia nest in the Great Barrier Reef (Australia) and vice versa. Several explanations exist for turtles exhibiting this energetically costly movement pattern from breeding to distant foraging grounds (1200-2680 km away) despite viable foraging habitat being available in the local vicinity. These include hatchling drift, oceanic movements and food abundance predictability. Most of the tag recoveries in New Caledonia belonged to females from the south Great Barrier Reef genetic stock. Some females (n = 2) even showed fidelity to foraging sites located 1200 km away from the nesting site located in New Caledonia. This study also reveals previously unknown migrations pathways of turtles within the Coral Sea.

Influence of fracture anisotropy on ground water ages and chemistry, Valley and Ridge province, Pennsylvania

USGS Publications Warehouse

Burton, W.C.; Plummer, Niel; Busenberg, E.; Lindsey, B.D.; Gburek, W.J.

2002-01-01

Model ground water ages based on chlorofluorocarbons (CFCs) and tritium/helium-3 (3H/3He) data were obtained from two arrays of nested piezometers located on the north limb of an anticline in fractured sedimentary rocks in the Valley and Ridge geologic province of Pennsylvania. The fracture geometry of the gently east plunging fold is very regular and consists predominately of south dipping to subhorizontal to north dipping bedding-plane parting and east striking, steeply dipping axial-plane spaced cleavage. In the area of the piezometer arrays, which trend north-south on the north limb of the fold, north dipping bedding-plane parting is a more dominant fracture set than is steeply south dipping axial-plane cleavage. The dating of ground water from the piezometer arrays reveals that ground water traveling along paths parallel to the dip direction of bedding-plane parting has younger 3H/3He and CFC model ages, or a greater component of young water, than does ground water traveling along paths opposite to the dip direction. In predominantly unmixed samples there is a strong positive correlation between age of the young fraction of water and dissolved sodium concentration. The travel times inferred from the model ages are significantly longer than those previously calculated by a ground water flow model, which assumed isotropically fractured layers parallel to topography. A revised model factors in the directional anisotropy to produce longer travel times. Ground water travel times in the watershed therefore appear to be more influenced by anisotropic fracture geometry than previously realized. This could have significant implications for ground water models in other areas underlain by similarly tilted or folded sedimentary rock, such as elsewhere in the Valley and Ridge or the early Mesozoic basins.

KSC-03pd0947

NASA Image and Video Library

2003-04-02

KENNEDY SPACE CENTER, FLA. - A female osprey occupies a nest recently constructed on a speaker in the lower parking lot of the Press Site. Eggs have been sighted in the nest. The NASA logo seen in the background is on the nearby Vehicle Assembly Building. Known as a fish hawk, the osprey selects sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States it is found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

KSC-04pd0901

NASA Image and Video Library

2004-04-20

KENNEDY SPACE CENTER, FLA. - Against the background of the NASA logo on the Vehicle Assembly Building, the osprey nest in the nearby parking lot reveals two fledglings and one of the adult ospreys. Known as a fish hawk, they often can be seen flying overhead with a fish in their talons. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-04pd0902

NASA Image and Video Library

2004-04-20

KENNEDY SPACE CENTER, FLA. - Against the background of the NASA logo on the Vehicle Assembly Building, the osprey nest in the nearby parking lot reveals two fledglings and one of the adult ospreys. Known as a fish hawk, they often can be seen flying overhead with a fish in their talons. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-04pd1211

NASA Image and Video Library

2004-05-17

KENNEDY SPACE CENTER, FLA. -- - Two young ospreys flex their wings for flight. Their nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04pd1212

NASA Image and Video Library

2004-05-17

KENNEDY SPACE CENTER, FLA. -- One young osprey tests its wings while another waits nearby. Their nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04pd1216

NASA Image and Video Library

2004-05-18

KENNEDY SPACE CENTER, FLA. -- A fledgling osprey soars above its nest, located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-0901

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Against the background of the NASA logo on the Vehicle Assembly Building, the osprey nest in the nearby parking lot reveals two fledglings and one of the adult ospreys. Known as a fish hawk, they often can be seen flying overhead with a fish in their talons. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-04PD-1211

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Two young ospreys flex their wings for flight. Their nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-1212

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One young osprey tests its wings while another waits nearby. Their nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-0902

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Against the background of the NASA logo on the Vehicle Assembly Building, the osprey nest in the nearby parking lot reveals two fledglings and one of the adult ospreys. Known as a fish hawk, they often can be seen flying overhead with a fish in their talons. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-04PD-1216

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- A fledgling osprey soars above its nest, located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

Detritus cast from heron nests as an indicator of food chain contamination. [Radioactivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rickard, W.H.; Hedlund, J.D.; Schreckhise, R.G.

Approximately 40 pairs of great blue herons nest in a single colony on the Hanford Reservation in south-central Washington. Over a two-month period in the 1975 nesting season, 170 g/m/sup 2/ of detritus, dry weight, were collected on cheesecloth blankets placed on the ground beneath the nesting colony. Seven gamma-emitting radionuclides commonly associated with airborne debris (fallout) were measured in the heron detritus. Cesium-137 was the most abundant man-induced radionuclide measured in the detritus averaging 18 picocuries per gram dry weight. Regular surveillance of heron detritus appears as a useful way to measure contaminants in heron foods gathered from themore » surrounding environment.« less

Pre-nesting and nesting behavior of the Swainson's warbler

USGS Publications Warehouse

Meanley, B.

1969-01-01

The Swainson?s Warbler is one of the least known of southern birds. Although fairly common in some parts of its summer range, observations of its breeding biology have been made by very few persons. The present study was conducted mostly at Macon, Georgia; Pendleton Ferry, Arkansas; and Dismal Swamp, Virginia....In central Georgia and east-central Arkansas, Swainson?s Warblers usually arrive on their territories during the first two weeks in April. Territories in several localities ranged in size from 0.3 to 4.8 acres. A color-marked Arkansas male occupied the same territory for at least four months. Hostile encounters between territorial male Swainson?s Warblers usually take place along the boundary of adjacent territories. Paired males were more aggressive than unpaired males. Toward the end of an encounter one of the two males would usually perform a display in which the wing and tail feathers were spread and the tail vibrated. Following boundary encounters males drifted back onto their territories and usually sang unbroken courses of songs for several minutes.....During pre-nesting at Macon, a mated pair spent the day mostly on the ground within 20 feet of each other, often foragin g 3 to 4 feet apart. What may have been a form of courtship display, in which the male flew from a perch down to the female and either pecked her rump or pounced on her, occurred about three times each hour throughout the day. During this period the male sang less than at other times during the breeding season.....First nests are usually built by the first week in May. Although other investigators reported finding nests of this species outside of the defended territory, all nests that I have found were within the territory. The large, bulky nest of this species usually is placed 2-6 feet above the ground. It is built by the female from materials gathered close to the nest site; and takes two or three days to complete.....Three and occasionally four white eggs are laid. The female incubates for 14-15 days. The Cowbird parasitizes nests in some parts of the breeding range of the Swainson?s Warbler.....During incubation the female spends about 78 per cent of daylight time on the nest. Both sexes feed young and clean nest. Young remain in nest from 10-12 days.

Productivity and breeding habitat of loggerhead shrikes in a southwestern urban environment

USGS Publications Warehouse

Boal, C.W.; Estabrook, T.S.; Duerr, A.E.

2003-01-01

Declines in loggerhead shrike (Lanius ludovicianus) populations have been associated in part with habitat loss and degradation, including that resulting from urbanization. We monitored the productivity and examined nesting habitat of loggerhead shrikes nesting in an urban environment in Tucson, Arizona. We located 22 breeding pairs in 1997 and 26 breeding pairs in 1998, with a 72% breeding area reoccupancy between years. Mean fledgling numbers were 2.28/ nesting attempt and 3.11/successful nest. Although some pairs initially failed and renested, 91% and 73% of shrike pairs successfully fledged young in 1997 and 1998, respectively. Mayfield estimates of nesting success were 78% in 1997 and 65% in 1998. Nest sites were characterized by more trees >3 m in height, taller nest trees than those randomly available, and a greater proportion of bare ground surface than at random sites. Shrike breeding territories had lower proportions of residential and commercial development and greater proportions of open areas with low-growing vegetation than randomly available. Some shrikes nested in school playgrounds, residential front yards, and parking lots, if adjacent open space was available.

Conservation of the yellow-shouldered blackbird, Agelaius xanthomus, an endangered West Indian species

USGS Publications Warehouse

Wiley, J.W.; Post, W.; Cruz, A.

1991-01-01

The yellow-shouldered blackbird Agelaius xanthomus, endemic to Puerto Rico and Mona Island, is endangered, mainly because of brood parasitism by the shiny cowbird Molothrus bonariensis, which reached Puerto Rico at least 30 years ago. The yellow-shouldered blackbird populations have since declined, about 770?1200 remaining (470?900 on Mona Island) by 1982?1986 compared to a population of about 2400 in 1975. Nearly all nests of blackbirds in most of its habitats are parasitized by cowbirds. This significantly reduces nesting success, but blackbirds have evolved no defenses against brood parasitism. Removal of cowbirds from the yellow-shouldered blackbird nesting grounds, modeled after similar programmes for the brown-headed cowbird Molothrus ater on Kirtland's warbler Dendroica kirtlandii nesting areas, significantly increased blackbird production. Blackbirds readily accept nest boxes, and breeding populations can be established in otherwise unusable sites and can be concentrated in mangrove habitats, were they are more easily protected by cowbird removal. Furthermore, yellow-shouldered blackbird pairs using cavities, including nest boxes, fledged more young per nest than pairs using open nests.

Effects of Invasive European Fire Ants (Myrmica rubra) on Herring Gull (Larus argentatus) Reproduction

PubMed Central

DeFisher, Luke E.; Bonter, David N.

2013-01-01

Various invasive ant species have negatively affected reproductive success in birds by disrupting nest site selection, incubation patterns, food supply, and by direct predation on nestlings. Impacts can be particularly severe when non-native ants colonize seabird nesting islands where thousands of birds may nest in high densities on the ground or in burrows or crevices. Here we report on the first documented effects of Myrmica rubra, the European fire ant, on the reproduction of birds in its non-native range. We documented herring gulls (Larus argentatus) on Appledore Island, Maine, engaging in more erratic incubation behaviors at nests infested by the ants. Newly-hatched chicks in some nests were swarmed by ants, leading to rapid chick death. Due to high overall rates of chick mortality, survival probabilities did not vary between nests with and without ant activity, however chick growth rates were slower at nests with ants than at ant-free nests. Ant infestation likely leads to longer-term fitness consequences because slower growth rates early in life may ultimately lead to lower post-fledging survival probabilities. PMID:23691168

Spatial patterns and temporal variability in water quality from City of Albuquerque drinking-water supply wells and piezometer nests, with implications for the ground-water flow system

USGS Publications Warehouse

Bexfield, Laura M.; Anderholm, Scott K.

2002-01-01

Water-quality data for 93 City of Albuquerque drinking-water supply wells, 7 deep piezometer nests, and selected additional wells were examined to improve understanding of the regional ground-water system and its response to pumpage. Plots of median values of several major parameters showed discernible water-quality differences both areally and with depth in the aquifer. Areal differences were sufficiently large to enable delineation of five regions of generally distinct water quality, which are consistent with areas of separate recharge defined by previous investigators. Data for deep piezometer nests indicate that water quality generally degrades somewhat with depth, except in areas where local recharge influenced by evapotranspiration or contamination could be affecting shallow water. The orientations of the five water-quality regions indicate that the direction of ground-water flow has historically been primarily north to south. This is generally consistent with maps of predevelopment hydraulic heads, although some areas lack consistency, possibly because of differences in time scales or depths represented by water quality as opposed to hydraulic head. The primary sources of recharge to ground water in the study area appear to be mountain-front recharge along the Sandia Mountains to the east and the Jemez Mountains to the north, seepage from the Rio Grande, and infiltration through Tijeras Arroyo. Elevated concentrations of many chemical constituents in part of the study area appear to be associated with a source of water having large dissolved solids, possibly moving upward from depth. Hydraulic-head data for deep piezometer nests indicate that vertical head gradients differ in direction and magnitude across the study area. Hydraulic-head gradients are downward in the central and western parts of the study area and upward across much of the eastern part, except at the mountain front. Water-quality data for the piezometers indicate that the ground water is not well mixed, even in areas of large vertical gradients. Water levels in most piezometers respond to short-term variations in ground-water withdrawals and to the cumulative effect of long-term withdrawals throughout the area. In most piezometers screened below the water table, water levels respond clearly to seasonal variations in ground-water withdrawals. Water levels decline from about April through July and rise from about September through January. Water levels seem to be declining in most piezometers at a rate less than 1 foot per year. Water-quality data for unfiltered samples collected over a 10-year period from 93 City of Albuquerque drinking-water supply wells were examined for variability and temporal trends in 10 selected parameters. Variability generally was found to be greatest in the Western and Northeast water-quality regions of the study area. For the 10 parameters investigated, temporal trends were found in 5 to 57 wells. Dissolved-solids, sodium, sulfate, chloride, and silica concentrations showed more increasing than decreasing trends; calcium, bicarbonate, and arsenic concentrations, field pH, and water temperature showed more decreasing than increasing trends. The median magnitudes of most of these trends over a 1-year period were not particularly large (generally less than 1.0 milligram per liter), although the magnitudes for a few individual wells were significant. For the 10 parameters investigated, correlations with monthly pumpage volumes were found in 10 to 32 wells. Calcium and sulfate concentrations, field pH, and water temperature showed more positive than negative correlations with monthly pumpage; dissolved-solids, sodium, bicarbonate, chloride, silica, and arsenic concentrations showed more negative than positive correlations. An increase in pumpage in an individual well appears to increase the contribution

Predation on Artificial Nests in Hurricane-Created Gaps and Adjacent Forest of the Southern Appalachians

Treesearch

Cathryn H. Greenberg; C. Reed Rossell; David B. Johnson

2002-01-01

Predation rates were compared during three 7-day trials on 742 artificial ground nests located in 10 hurricane-created canopy gaps and IO adjacent closed-canopy controls in the southern Appalachian mountains of North Carolina. White northern bobwhite (Colinus virginianus) eggs were used in trials 1 and 2, but brown-speckled Japanese Quail (...

Improvement of individual camouflage through background choice in ground-nesting birds.

PubMed

Stevens, Martin; Troscianko, Jolyon; Wilson-Aggarwal, Jared K; Spottiswoode, Claire N

2017-09-01

Animal camouflage is a longstanding example of adaptation. Much research has tested how camouflage prevents detection and recognition, largely focusing on changes to an animal's own appearance over evolution. However, animals could also substantially alter their camouflage by behaviourally choosing appropriate substrates. Recent studies suggest that individuals from several animal taxa could select backgrounds or positions to improve concealment. Here, we test whether individual wild animals choose backgrounds in complex environments, and whether this improves camouflage against predator vision. We studied nest site selection by nine species of ground-nesting birds (nightjars, plovers and coursers) in Zambia, and used image analysis and vision modeling to quantify egg and plumage camouflage to predator vision. Individual birds chose backgrounds that enhanced their camouflage, being better matched to their chosen backgrounds than to other potential backgrounds with respect to multiple aspects of camouflage. This occurred at all three spatial scales tested (a few cm and five meters from the nest, and compared to other sites chosen by conspecifics), and was the case for the eggs of all bird groups studied, and for adult nightjar plumage. Thus, individual wild animals improve their camouflage through active background choice, with choices highly refined across multiple spatial scales.

Improvement of individual camouflage through background choice in ground-nesting birds

PubMed Central

Stevens, Martin; Troscianko, Jolyon; Wilson-Aggarwal, Jared K.; Spottiswoode, Claire N.

2017-01-01

Animal camouflage is a longstanding example of adaptation. Much research has tested how camouflage prevents detection and recognition, largely focusing on changes to an animal's own appearance over evolution. However, animals could also substantially alter their camouflage by behaviourally choosing appropriate substrates. Recent studies suggest that individuals from several animal taxa could select backgrounds or positions to improve concealment. Here, we test whether individual wild animals choose backgrounds in complex environments, and whether this improves camouflage against predator vision. We studied nest site selection by nine species of ground-nesting birds (nightjars, plovers and coursers) in Zambia, and used image analysis and vision modeling to quantify egg and plumage camouflage to predator vision. Individual birds chose backgrounds that enhanced their camouflage, being better matched to their chosen backgrounds than to other potential backgrounds with respect to multiple aspects of camouflage. This occurred at all three spatial scales tested (a few cm and five meters from the nest, and compared to other sites chosen by conspecifics), and was the case for the eggs of all bird groups studied, and for adult nightjar plumage. Thus, individual wild animals improve their camouflage through active background choice, with choices highly refined across multiple spatial scales. PMID:28890937

Nest site attributes and temporal patterns of northern flicker nest loss: effects of predation and competition.

PubMed

Fisher, Ryan J; Wiebe, Karen L

2006-04-01

To date, most studies of nest site selection have failed to take into account more than one source of nest loss (or have combined all sources in one analysis) when examining nest site characteristics, leaving us with an incomplete understanding of the potential trade-offs that individuals may face when selecting a nest site. Our objectives were to determine whether northern flickers (Colaptes auratus) may experience a trade-off in nest site selection in response to mammalian nest predation and nest loss to a cavity nest competitor (European starling, Sturnus vulgaris). We also document within-season temporal patterns of these two sources of nest loss with the hypothesis that flickers may also be constrained in the timing of reproduction under both predatory and competitive influence. Mammalian predators frequently depredated flicker nests that were: lower to the ground, less concealed by vegetation around the cavity entrance and at the base of the nest tree, closer to coniferous forest edges and in forest clumps with a high percentage of conifer content. Proximity to coniferous edges or coniferous trees increased the probability of nest predation, but nests near conifers were less likely to be lost to starlings. Flickers may thus face a trade-off in nest site selection with respect to safety from predators or competitors. Models suggested that peaks of nest predation and nest loss to eviction occurred at the same time, although a competing model suggested that the peak of nest loss to starlings occurred 5 days earlier than the peak of mammalian predation. Differences in peaks of mammalian predation and loss to starlings may constrain any adjustment in clutch initiation date by flickers to avoid one source of nest loss.

Arboreal nesting as anti-predator adaptation by savanna chimpanzees (Pan troglodytes verus) in southeastern Senegal.

PubMed

Pruetz, J D; Fulton, S J; Marchant, L F; McGrew, W C; Schiel, M; Waller, M

2008-04-01

Chimpanzees (Pan troglodytes) make nests for resting and sleeping, which is unusual for anthropoid primates but common to all great apes. Arboreal nesting has been linked to predation pressure, but few studies have tested the adaptive nature of this behavior. We collected data at two chimpanzee study sites in southeastern Senegal that differed in predator presence to test the hypothesis that elevated sleeping platforms are adaptations for predator defense. At Assirik in the Parc National du Niokolo-Koba, chimpanzees face four species of large carnivore, whereas at Fongoli, outside national park boundaries, humans have exterminated almost all natural predators. We quantified the availability of vegetation at the two sites to test the alternative hypothesis that differences in nesting reflect differences in habitat structure. We also examined possible sex differences in nesting behavior, community demographic differences, seasonality and nest age differences as variables also potentially affecting nest characteristics and nesting behavior between the two sites. Chimpanzees at Fongoli nested at lower heights and farther apart than did chimpanzees at Assirik and sometimes made nests on the ground. The absence of predators outside of the national park may account for the differences in nest characteristics at the two sites, given the similarities in habitat structure between Fongoli and Assirik. However, Fongoli chimpanzees regularly build arboreal nests for sleeping, even under minimal predation pressure, and this requires explanation.

Nest substrate reflects incubation style in extant archosaurs with implications for dinosaur nesting habits.

PubMed

Tanaka, Kohei; Zelenitsky, Darla K; Therrien, François; Kobayashi, Yoshitsugu

2018-03-15

Dinosaurs thrived and reproduced in various regions worldwide, including the Arctic. In order to understand their nesting in diverse or extreme environments, the relationships between nests, nesting environments, and incubation methods in extant archosaurs were investigated. Statistical analyses reveal that species of extant covered nesters (i.e., crocodylians and megapodes) preferentially select specific sediments/substrates as a function of their nesting style and incubation heat sources. Relationships between dinosaur eggs and the sediments in which they occur reveal that hadrosaurs and some sauropods (i.e., megaloolithid eggs) built organic-rich mound nests that relied on microbial decay for incubation, whereas other sauropods (i.e., faveoloolithid eggs) built sandy in-filled hole nests that relied on solar or potentially geothermal heat for incubation. Paleogeographic distribution of mound nests and sandy in-filled hole nests in dinosaurs reveals these nest types produced sufficient incubation heat to be successful up to mid latitudes (≤47°), 10° higher than covered nesters today. However, only mound nesting and likely brooding could have produced sufficient incubation heat for nesting above the polar circle (>66°). As a result, differences in nesting styles may have placed restrictions on the reproduction of dinosaurs and their dispersal at high latitudes.

Reproductive success of migratory birds in habitat sources and sinks

Treesearch

Therese M. Donovan; Frank R. , III Thompson; John Faaborg; John R. Probst

1995-01-01

Fragmentation of breeding habitat in North America has been implicated in the decline of forest-nesting, Neotropical migrant birds. We used a comparative approach to examine the effects of fragmentation on three forest-nesting migrants: Ovenbird (Seiurus aurocapillus), Red-eyed Vireo (Vireo ofivaceus), and Wood Thrush (...

Predicted fates of ground-nesting bees in soil heated by wildfire: Thermal tolerances of life stages and a survey of nesting depths

Treesearch

James H. Cane; John L. Neff

2011-01-01

Periodic wildfire defines plant community composition and dynamics in many of the world's semi-arid biomes, whose climates and floras also favor wild bee diversity. Invasive flammable grasses, deforestation, historical fire suppression and human ignition are increasing fire frequency and intensifying its severity, as well as introducing fire to previously...

Assessing exotic plant species invasions and associated soil characteristics: A case study in eastern Rocky Mountain National Park, Colorado, USA, using the pixel nested plot design

USGS Publications Warehouse

Kalkhan, M.A.; Stafford, E.J.; Woodly, P.J.; Stohlgren, T.J.

2007-01-01

Rocky Mountain National Park (RMNP), Colorado, USA, contains a diversity of plant species. However, many exotic plant species have become established, potentially impacting the structure and function of native plant communities. Our goal was to quantify patterns of exotic plant species in relation to native plant species, soil characteristics, and other abiotic factors that may indicate or predict their establishment and success. Our research approach for field data collection was based on a field plot design called the pixel nested plot. The pixel nested plot provides a link to multi-phase and multi-scale spatial modeling-mapping techniques that can be used to estimate total species richness and patterns of plant diversity at finer landscape scales. Within the eastern region of RMNP, in an area of approximately 35,000 ha, we established a total of 60 pixel nested plots in 9 vegetation types. We used canonical correspondence analysis (CCA) and multiple linear regressions to quantify relationships between soil characteristics and native and exotic plant species richness and cover. We also used linear correlation, spatial autocorrelation and cross correlation statistics to test for the spatial patterns of variables of interest. CCA showed that exotic species were significantly (P < 0.05) associated with photosynthetically active radiation (r = 0.55), soil nitrogen (r = 0.58) and bare ground (r = -0.66). Pearson's correlation statistic showed significant linear relationships between exotic species, organic carbon, soil nitrogen, and bare ground. While spatial autocorrelations indicated that our 60 pixel nested plots were spatially independent, the cross correlation statistics indicated that exotic plant species were spatially associated with bare ground, in general, exotic plant species were most abundant in areas of high native species richness. This indicates that resource managers should focus on the protection of relatively rare native rich sites with little canopy cover, and fertile soils. Using the pixel nested plot approach for data collection can facilitate the ecological monitoring of these vulnerable areas at the landscape scale in a time- and cost-effective manner. ?? 2006 Elsevier B.V. All rights reserved.

Grasshopper sparrow reproductive success and habitat use on reclaimed surface mines varies by age of reclamation

USGS Publications Warehouse

Wood, Petra; Ammer, Frank K.

2015-01-01

We studied 3 mountaintop mining–valley fill (MTMVF) complexes in southern West Virginia, USA to examine grasshopper sparrow (Ammodramus savannarum pratensis) demographic response to different age classes of mine land reclamation. For 71 nests monitored during the 2001–2002 breeding seasons, overall nest success (36%) was within the range of nest success rates previously reported for this species, but it was highest on more recently reclaimed sites (56%). Nest density and clutch size did not differ (P > 0.30) among reclamation age classes, whereas number of fledglings was greater (P = 0.01) on more recently reclaimed sites. We measured vegetation variables at 70 nest subplots and at 96 systematic subplots to compare nest vegetation with vegetation available on the plots. We found that nests occurred in areas with more bare ground near the nest, greater vegetation height–density surrounding the nest site, lower grass height, and fewer woody stems, similar to previous studies. As postreclamation age increased, vegetation height–density and maximum grass height increased, and sericea (Lespedeza cuneata) became more dominant. Nest success declined with increasing vegetation height–density at the nest. The grasslands available on these reclaimed mine complexes are of sufficient quality to support breeding populations of grasshopper sparrows, but nest success decreased on the older reclaimed areas. Without active management, grasslands on reclaimed MTMVF mines become less suitable for nesting grasshopper sparrows about 10 years after reclamation.

Avian nest success in midwestern forests fragmented by agriculture

USGS Publications Warehouse

Knutson, M.G.; Niemi, G.J.; Newton, W.E.; Friberg, M.A.

2004-01-01

We studied how forest-bird nest success varied by landscape context from 1996 to 1998 in an agricultural region of southeastern Minnesota, southwestern Wisconsin, and northeastern Iowa. Nest success was 48% for all nests, 82% for cavity-nesting species, and 42% for cup-nesting species. Mayfield-adjusted nest success for five common species ranged from 23% for the American Redstart (Setophaga ruticilla) to 43% for the Eastern Wood-Pewee (Contopus virens). Nest success was lowest for open-cup nesters, species that reject Brown-headed Cowbird (Molothrus ater) eggs, species that nest near forest edges, and Neo-tropical migrants. The proportion of forest core area in a 5-km radius around the plot had a weakly negative relationship with daily survival rate of nests for all species pooled and for medium or high canopy nesters, species associated with interior and edge habitats, open-cup nesters, and nests located between 75 and 199 m from an edge. The proportion of forest core area was positively related to daily survival rate only for ground and low nesters. Our findings are in contrast to a number of studies from the eastern United States reporting strong positive associations between forest area and nesting success. Supported models of habitat associations changed with the spatial scale of analysis and included variables not often considered in studies of forest birds, including the proportion of water, shrubs, and grasslands in the landscape. Forest area may not be a strong indicator of nest success in landscapes where all the available forests are fragmented.

Facial bristle feather histology and morphology in New Zealand birds: implications for function.

PubMed

Cunningham, Susan J; Alley, Maurice R; Castro, Isabel

2011-01-01

Knowledge of structure in biology may help inform hypotheses about function. Little is known about the histological structure or the function of avian facial bristle feathers. Here we provide information on morphology and histology, with inferences for function, of bristles in five predominantly insectivorous birds from New Zealand. We chose species with differing ecologies, including: brown kiwi (Apteryx mantelli), morepork (Ninox novaezealandae), hihi (Notiomystis cincta), New Zealand robin (Petroica australis), and New Zealand fantail (Rhipidura fuliginosa). Average bristle length corrected for body size was similar across species. Bristles occurred in distinct groups on different parts of the head and upper rictal bristles were generally longest. The lower rictal bristles of the fantail were the longest possessed by that species and were long compared to bristles of other species. Kiwi were the only species with forehead bristles, similar in length to the upper rictal bristles of other species, and the lower rictal bristles of fantails. Herbst corpuscles (vibration and pressure sensitive mechanoreceptors) were found in association with bristle follicles in all species. Nocturnal and hole-nesting birds had more heavily encapsulated corpuscles than diurnal open-nesting species. Our results suggest that avian facial bristles generally have a tactile function in both nocturnal and diurnal species, perhaps playing a role in prey handling, gathering information during flight, navigating in nest cavities and on the ground at night and possibly in prey-detection. These differing roles may help explain the observed differences in capsule thickness of the corpuscles. Copyright © 2010 Wiley-Liss, Inc.

Spring migration of Northern Pintails from Texas and New Mexico, USA

USGS Publications Warehouse

Haukos, D.A.; Miller, M.R.; Orthmeyer, D.L.; Takekawa, John Y.; Fleskes, J.P.; Casazza, Michael L.; Perry, W.M.; Moon, J.A.

2006-01-01

We used satellite transmitters (platform transmitting terminals or PTTs) during 2002 and 2003 to document spring migration timing, routes, stopover sites, and nesting sites of adult female Northern Pintails (Anas acuta) from major wintering areas of the Gulf Coast (N = 20) and Playa Lakes Regions (PLR, N = 20) in Texas, and the Middle Rio Grande Valley, New Mexico (MRGV, N = 15). Some Pintails tagged in the MRGV continued movements into Mexico. Poor winter survival or PTT failure reduced sample size to 15 for PLR Pintails, 5 for Gulf Coast Pintails, and 11 for MRGV Pintails. Apparent winter survival was 66% lower for Texas Gulf Coast PTT-tagged Pintails than for those from the PLR and MRGV. Pintails from each area used different routes to their respective breeding grounds. PTT-tagged Pintails from the MRGV followed the Rio Grande Valley north to southern Colorado, before traveling on to the Dakotas and Canada or traveled northeast and joined the migration of PLR Pintails in Texas or Kansas. The latter made initial stops in Kansas, Nebraska, Colorado, or the Dakotas. Gulf Coast Pintails traveled through north-central Oklahoma or central Kansas. Pintails that had stopped first in Kansas or Nebraska tended to settle to nest in the United States. Wetland availability in the Prairie Pothole Region of the Northern Great Plains influenced nesting destinations of PTT-tagged Pintails, but individuals settled across a wide swath of northern North America. We did not detect any consistently-used spring staging areas. Therefore, negative impacts to any of the marked populations, or their wetland habitats, may have continental implications.

Influence of olfactory and visual cover on nest site selection and nest success for grassland-nesting birds.

PubMed

Fogarty, Dillon T; Elmore, R Dwayne; Fuhlendorf, Samuel D; Loss, Scott R

2017-08-01

Habitat selection by animals is influenced by and mitigates the effects of predation and environmental extremes. For birds, nest site selection is crucial to offspring production because nests are exposed to extreme weather and predation pressure. Predators that forage using olfaction often dominate nest predator communities; therefore, factors that influence olfactory detection (e.g., airflow and weather variables, including turbulence and moisture) should influence nest site selection and survival. However, few studies have assessed the importance of olfactory cover for habitat selection and survival. We assessed whether ground-nesting birds select nest sites based on visual and/or olfactory cover. Additionally, we assessed the importance of visual cover and airflow and weather variables associated with olfactory cover in influencing nest survival. In managed grasslands in Oklahoma, USA, we monitored nests of Northern Bobwhite ( Colinus virginianus ), Eastern Meadowlark ( Sturnella magna ), and Grasshopper Sparrow ( Ammodramus savannarum ) during 2015 and 2016. To assess nest site selection, we compared cover variables between nests and random points. To assess factors influencing nest survival, we used visual cover and olfactory-related measurements (i.e., airflow and weather variables) to model daily nest survival. For nest site selection, nest sites had greater overhead visual cover than random points, but no other significant differences were found. Weather variables hypothesized to influence olfactory detection, specifically precipitation and relative humidity, were the best predictors of and were positively related to daily nest survival. Selection for overhead cover likely contributed to mitigation of thermal extremes and possibly reduced detectability of nests. For daily nest survival, we hypothesize that major nest predators focused on prey other than the monitored species' nests during high moisture conditions, thus increasing nest survival on these days. Our study highlights how mechanistic approaches to studying cover informs which dimensions are perceived and selected by animals and which dimensions confer fitness-related benefits.

Dispersal and Diving Adjustments of the Green Turtle Chelonia mydas in Response to Dynamic Environmental Conditions during Post-Nesting Migration

PubMed Central

Chambault, Philippine; Pinaud, David; Vantrepotte, Vincent; Kelle, Laurent; Entraygues, Mathieu; Guinet, Christophe; Berzins, Rachel; Bilo, Karin; Gaspar, Philippe; de Thoisy, Benoît; Le Maho, Yvon; Chevallier, Damien

2015-01-01

In response to seasonality and spatial segregation of resources, sea turtles undertake long journeys between their nesting sites and foraging grounds. While satellite tracking has made it possible to outline their migration routes, we still have little knowledge of how they select their foraging grounds and adapt their migration to dynamic environmental conditions. Here, we analyzed the trajectories and diving behavior of 19 adult green turtles (Chelonia mydas) during their post-nesting migration from French Guiana and Suriname to their foraging grounds off the coast of Brazil. First Passage Time analysis was used to identify foraging areas located off Ceará state of Brazil, where the associated habitat corresponds to favorable conditions for seagrass growth, i.e. clear and shallow waters. The dispersal and diving patterns of the turtles revealed several behavioral adaptations to the strong hydrodynamic processes induced by both the North Brazil current and the Amazon River plume. All green turtles migrated south-eastward after the nesting season, confirming that they coped with the strong counter North Brazil current by using a tight corridor close to the shore. The time spent within the Amazon plume also altered the location of their feeding habitats as the longer individuals stayed within the plume, the sooner they initiated foraging. The green turtles performed deeper and shorter dives while crossing the mouth of the Amazon, a strategy which would help turtles avoid the most turbulent upper surface layers of the plume. These adjustments reveal the remarkable plasticity of this green turtle population when reducing energy costs induced by migration. PMID:26398528

Dispersal and Diving Adjustments of the Green Turtle Chelonia mydas in Response to Dynamic Environmental Conditions during Post-Nesting Migration.

PubMed

Chambault, Philippine; Pinaud, David; Vantrepotte, Vincent; Kelle, Laurent; Entraygues, Mathieu; Guinet, Christophe; Berzins, Rachel; Bilo, Karin; Gaspar, Philippe; de Thoisy, Benoît; Le Maho, Yvon; Chevallier, Damien

2015-01-01

In response to seasonality and spatial segregation of resources, sea turtles undertake long journeys between their nesting sites and foraging grounds. While satellite tracking has made it possible to outline their migration routes, we still have little knowledge of how they select their foraging grounds and adapt their migration to dynamic environmental conditions. Here, we analyzed the trajectories and diving behavior of 19 adult green turtles (Chelonia mydas) during their post-nesting migration from French Guiana and Suriname to their foraging grounds off the coast of Brazil. First Passage Time analysis was used to identify foraging areas located off Ceará state of Brazil, where the associated habitat corresponds to favorable conditions for seagrass growth, i.e. clear and shallow waters. The dispersal and diving patterns of the turtles revealed several behavioral adaptations to the strong hydrodynamic processes induced by both the North Brazil current and the Amazon River plume. All green turtles migrated south-eastward after the nesting season, confirming that they coped with the strong counter North Brazil current by using a tight corridor close to the shore. The time spent within the Amazon plume also altered the location of their feeding habitats as the longer individuals stayed within the plume, the sooner they initiated foraging. The green turtles performed deeper and shorter dives while crossing the mouth of the Amazon, a strategy which would help turtles avoid the most turbulent upper surface layers of the plume. These adjustments reveal the remarkable plasticity of this green turtle population when reducing energy costs induced by migration.

Migration patterns, use of stopover areas, and austral summer movements of Swainson's hawks

USGS Publications Warehouse

Kocher, Michael N.; Fuller, Mark R.; Schueck, Linda S.; Bond, Laura; Bechard, Marc J.; Woodbridge, Brian; Holroyd, Geoff L.; Martell, Mark S.; Banasch, Ursula

2011-01-01

from 1995 to 1998, we tracked movements of adult Swainson's Hawks (Buteo swainsoni), using satellite telemetry to characterize migration, important stopover areas, and movements in the austral summer. we tagged 46 hawks from July to September on their nesting grounds in seven U.S. states and two Canadian provinces. Swainson's Hawks followed three basic routes south on a broad front, converged along the east coast of cen-tral Mexico, and followed a concentrated corridor to a communal area in central Argentina for the austral summer. North of 20° N, southward and northward tracks differed little for individuals from east of the continental divide but differed greatly (up to 1700 km) for individuals from west of the continental divide. Hawks left the breeding grounds mid-August to mid-October; departure dates did not differ by location, year, or sex. Southbound migra-tion lasted 42 to 98 days, northbound migration 51 to 82 days. Southbound, 36% of the Swainson's Hawks departed the nesting grounds nearly 3 weeks earlier than the other radio-marked hawks and made stopovers 9.0–26.0 days long in seven separate areas, mainly in the southern great Plains, southern Arizona and New Mexico, and north-central Mexico. The birds stayed in their nonbreeding range for 76 to 128 days. All used a core area in central Ar-gentina within 23% of the 738 800-km2 austral summer range, where they frequently moved long distances (up to 1600 km). Conservation of Swainson's Hawks must be an international effort that considers habitats used during nesting and non-nesting seasons, including migration stopovers.

Sampling animal sign in heterogeneous environments: how much is enough?

USGS Publications Warehouse

Holbrook, Joseph D.; Arkle, Robert S.; Rachlow, Janet L.; Vierling, Kerri T.; Pilliod, David S.

2015-01-01

Animal ecologists often use animal sign as a surrogate for direct observation of organisms, especially when species are secretive or difficult to observe. Spatial heterogeneity in arid environments makes it challenging to consistently detect and precisely characterize animal sign, which can bias estimates of animal abundance or habitat use. Piute ground squirrels (Urocitellus mollis) and Owyhee harvester ants (Pogonomyrmex salinus) live in arid environments and are fossorial, which can make them difficult to observe directly. Their relative abundance can be assessed using sign (i.e., burrows and nests). We implemented an over-sampling framework (i.e., recorded an excessive amount of information) with two observers to 1) identify a sampling intensity that balanced precision with our resource constraints, and 2) assess classification and detection of squirrel burrows and ant nests across vegetation conditions. We sampled 20 1-ha plots for ground squirrel burrows and ant nests using six 4 m × 100 m belt transects. Analyses of precision and sampling effort indicated that three belt transects covering 1200 m2 per ha provided sufficient precision, while minimizing effort. Regardless of vegetation conditions, counts by two observers were strongly correlated for ground squirrel burrows (r = 0.99, P < 0.001, df = 18; slope = 0.92) and harvester ant nests (r = 0.99, P < 0.001, df = 18; slope = 1.01) indicating observer consistency and perhaps high detection probability. These findings illustrate an approach for evaluating sampling designs in many ecological contexts.

MIGRATION PATTERNS, USE OF STOPOVER AREAS, AND AUSTRAL SUMMER MOVEMENTS OF SWAINSON'S HAWKS.

PubMed

Kochert, Michael N; Fuller, Mark R; Schueck, Linda S; Bond, Laura; Bechard, Marc J; Woodbridge, Brian; Holroyd, Geoff; Martell, Mark; Banasch, Ursula

From 1995-1998, we tracked movements of adult Swainson's Hawks ( Buteo swainsoni ) using satellite telemetry to characterize migration, important stopover areas, and austral summer movements. We tagged 46 hawks from July - September on their nesting grounds in seven U.S. states and two Canadian provinces. Swainson's Hawks basically followed three routes south on a broad front, converged along the east coast of central Mexico, and followed a concentrated corridor to a communal austral summer area in central Argentina. North of 20° N, southward and northward tracks differed little for individuals from east of the Continental Divide but differed greatly (up to 1700 km) for individuals from west of the Continental Divide. Hawks left the breeding grounds mid-August to mid-October; departure dates did not differ by location, year, or sex. South migration lasted 42 to 98 days, and north migration took 51 to 82 days. On south migration, 36% of the Swainson's Hawks departed the nesting grounds nearly 3 weeks earlier than the other radio marked hawks and made stopovers 9.0 - 26.0 days long in seven separate areas, mainly in the southern Great Plains, southern Arizona and New Mexico, and north-central Mexico. The austral period lasted 76 to 128 days. All Swainson's Hawks used a core area in central Argentina within 23% of the 738800 km 2 austral summer range where they frequently moved long distances (up to 1600 km). Conservation of Swainson's Hawks must be an international effort that considers habitats used during nesting and non-nesting seasons including migration stopovers.

KSC-04pd1218

NASA Image and Video Library

2004-05-18

KENNEDY SPACE CENTER, FLA. -- One of the fledgling ospreys from the nest in the NASA KSC News Center parking lot comes down for a rough landing in the nearby grass. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04pd1217

NASA Image and Video Library

2004-05-18

KENNEDY SPACE CENTER, FLA. -- One of the fledgling ospreys from the nest in the NASA KSC News Center parking lot lands on a sign after testing its wings. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04pd1214

NASA Image and Video Library

2004-05-17

KENNEDY SPACE CENTER, FLA. -- Two fledgling ospreys begin flight lessons with their parent nearby (right). Their nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-1213

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- An adult osprey hovers over two of its fledglings, perhaps encouraging them to fly. Their nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-1214

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Two fledgling ospreys begin flight lessons with their parent nearby (right). Their nest is located in the NASA KSC News Center parking lot. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-1218

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One of the fledgling ospreys from the nest in the NASA KSC News Center parking lot comes down for a rough landing in the nearby grass. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

KSC-04PD-1217

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One of the fledgling ospreys from the nest in the NASA KSC News Center parking lot lands on a sign after testing its wings. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food.

Variability in nest survival rates and implications to nesting studies

USGS Publications Warehouse

Klett, A.T.; Johnson, D.H.

1982-01-01

We used four reasonably large samples (83-213) of Mallard (Anas platyrhynchos) and Blue-winged Teal (A. discors) nests on an interstate highway right-of-way in southcentral North Dakota to evaluate potential biases in hatch-rate estimates. Twelve consecutive, weekly searches for nests were conducted with a cable-chain drag in 1976 and 1977. Nests were revisited at weekly intervals. Four methods were used to estimate hatch rates for the four data sets: the Traditional Method, the Mayfield Method, and two modifications of the Mayfield Method that are sometimes appropriate when daily mortality rates of nests are not constant. Hatch rates and the average age of nests at discovery declined as the interval between searches decreased, suggesting that mortality rates were not constant in our samples. An analysis of variance indicated that daily mortality rates varied with the age of nests in all four samples. Mortality was generally highest during the early laying period, moderately high during the late laying period, and lowest during incubation. We speculate that this relationship of mortality to nest age might be due to the presence of hens at nests or to differences in the vulnerability of nest sites to predation. A modification of the Mayfield Method that accounts for age-related variation in nest mortality was most appropriate for our samples. We suggest methods for conducting nesting studies and estimating nest success for species possessing similar nesting habits.

Leucophora Satellite Flies (Diptera: Anthomyiidae) as Nest Parasites of Sweat Bees (Hymenoptera: Halictidae) in the Neotropics.

PubMed

Polidori, C; Michelsen, V; Nieves-Aldrey, J L

2015-08-01

The biology of the 10 species of Leucophora (Diptera: Anthomyiidae) recorded in the Neotropics remains unknown. The large majority of the studied species so far are kleptoparasites of bees and wasps. Here, we report the first observations of Leucophora andicola (Bigot) and Leucophora peullae (Malloch) visiting the nests of ground-nesting sweat bees Corynura (Hymenoptera: Halictidae) in Chilean Patagonia. Females of both species perch on small stones or sticks within a dense nest aggregation of the bees and then track pollen-loaded bees in flight with great precision, eventually following them into their nests. The overall behavior closely resembles that observed for many other species of the genus. Excavations of some bee nests returned only two dipteran puparia, possibly of Leucophora, suggesting a low parasitism rate. One male of L. peullae was also collected at the bee aggregation. This is the first report of host association for any Leucophora from the Neotropics and the first report of any anthomyiid fly associated with augochlorine bees.

Bumblebee calligraphy: the design and control of flight motifs in the learning and return flights of Bombus terrestris.

PubMed

Philippides, Andrew; de Ibarra, Natalie Hempel; Riabinina, Olena; Collett, Thomas S

2013-03-15

Many wasps and bees learn the position of their nest relative to nearby visual features during elaborate 'learning' flights that they perform on leaving the nest. Return flights to the nest are thought to be patterned so that insects can reach their nest by matching their current view to views of their surroundings stored during learning flights. To understand how ground-nesting bumblebees might implement such a matching process, we have video-recorded the bees' learning and return flights and analysed the similarities and differences between the principal motifs of their flights. Loops that take bees away from and bring them back towards the nest are common during learning flights and less so in return flights. Zigzags are more prominent on return flights. Both motifs tend to be nest based. Bees often both fly towards and face the nest in the middle of loops and at the turns of zigzags. Before and after flight direction and body orientation are aligned, the two diverge from each other so that the nest is held within the bees' fronto-lateral visual field while flight direction relative to the nest can fluctuate more widely. These and other parallels between loops and zigzags suggest that they are stable variations of an underlying pattern, which enable bees to store and reacquire similar nest-focused views during learning and return flights.

Nesting frequency and success: implications for the demography of painted turtles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tinkle, D.W.; Congdon, J.D.; Rosen, P.C.

1981-12-01

Nesting ecology and reproduction of painted turtles (Chrysemys picta) in southeast Michigan were intensively studied from 1975 to 1978. The average clutch size of Michigan painted turtles was 7.55, with body size accounting for only 9-13% of the variance. Data on nesting frequency indicate that from 30 to 50% of the females possibly do not reproduce every year and that approx. =6% reproduce twice in a given year. Predation within 48 h of egg-laying is responsible for the failure of 20% of the nests. An additional 12% nest failure is due to various other causes. These data substantially alter themore » life table previously reported in this population of painted turtles.« less

Nesting frequency and success: implications for the demography of painted turtles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tinkle, D.W.; Congdon, J.D.; Rosen, P.C.

1981-12-01

Nesting ecology and reproduction of painted turtles (Chrysemys picta) in southeast Michigan were intensively studied from 1975 to 1978. The average clutch size of Michigan painted turtles was 7.55, with body size accounting for only 9-13% of the variance. Data on nesting frequency indicate that from 30 to 50% of the females possibly do not reproduce every year and that approx.6% reproduce twice in a given year. Predation within 48 h of egg-laying is responsible for the failure of 20% of the nests. An additional 12% nest failure is due to various other causes. These data substantially alter the lifemore » table previously reported for this population of painted turtles.« less

Seabird species vary in behavioural response to drone census.

PubMed

Brisson-Curadeau, Émile; Bird, David; Burke, Chantelle; Fifield, David A; Pace, Paul; Sherley, Richard B; Elliott, Kyle H

2017-12-20

Unmanned aerial vehicles (UAVs) provide an opportunity to rapidly census wildlife in remote areas while removing some of the hazards. However, wildlife may respond negatively to the UAVs, thereby skewing counts. We surveyed four species of Arctic cliff-nesting seabirds (glaucous gull Larus hyperboreus, Iceland gull Larus glaucoides, common murre Uria aalge and thick-billed murre Uria lomvia) using a UAV and compared censusing techniques to ground photography. An average of 8.5% of murres flew off in response to the UAV, but >99% of those birds were non-breeders. We were unable to detect any impact of the UAV on breeding success of murres, except at a site where aerial predators were abundant and several birds lost their eggs to predators following UAV flights. Furthermore, we found little evidence for habituation by murres to the UAV. Most gulls flew off in response to the UAV, but returned to the nest within five minutes. Counts of gull nests and adults were similar between UAV and ground photography, however the UAV detected up to 52.4% more chicks because chicks were camouflaged and invisible to ground observers. UAVs provide a less hazardous and potentially more accurate method for surveying wildlife. We provide some simple recommendations for their use.

Chimpanzees (Pan troglodytes) Flexibly Use Introduced Species for Nesting and Bark Feeding in a Human-Dominated Habitat.

PubMed

McCarthy, Maureen S; Lester, Jack D; Stanford, Craig B

2017-01-01

As habitat loss and fragmentation place growing pressure on endangered nonhuman primate populations, researchers find increasing evidence for novel responses in behavior. In western Uganda between the Budongo and Bugoma Forests, chimpanzees ( Pan troglodytes schweinfurthii ) inhabit a mosaic landscape comprising forest fragments, human settlements, and agricultural land. We recorded nests and feeding evidence of unhabituated chimpanzees in this region over a 12-mo period. We found extensive evidence of nesting in introduced tree species, including eucalyptus ( Eucalyptus grandis ), guava ( Psidium guajava ), cocoa ( Theobroma cacao ), and Caribbean pine ( Pinus caribaea ). In addition, we found instances of ground nesting, nest reuse, and composite nests constructed from branches of multiple trees. This evidence may indicate a lack of suitable nesting trees or attempts by chimpanzees to nest in areas of riparian forest that allow them to avoid human detection. We also found new evidence for eucalyptus bark feeding by chimpanzees. Such evidence suggests chimpanzees respond flexibly to mitigate anthropogenic pressures in human-dominated landscapes. The limits of such flexibility remain unknown. Further research is needed to examine systematically the factors influencing the use of such resources and to understand better the extent to which chimpanzees can persist while relying on them.

Ecological factors related to the widespread distribution of sylvatic Rhodnius ecuadoriensis populations in southern Ecuador

PubMed Central

2012-01-01

Background Chagas disease transmission risk is a function of the presence of triatomines in domestic habitats. Rhodnius ecuadoriensis is one of the main vectors implicated in transmission of Trypanosoma cruzi in Ecuador. This triatomine species is present in domestic, peridomestic and sylvatic habitats in the country. To determine the distribution of sylvatic populations of R. ecuadoriensis and the factors related to this distribution, triatomine searches were conducted between 2005 and 2009 in southern Ecuador. Methods Manual triatomine searches were conducted by skilled bug collectors in 23 communities. Sylvatic searched sites were selected by a) directed sampling, where microhabitats were selected by the searchers and b) random sampling, where sampling points where randomly generated. Domiciliary triatomine searches were conducted using the one man-hour method. Natural trypanosome infection was determined by microscopic examination and PCR. Generalized linear models were used to test the effect of environmental factors on the presence of sylvatic triatomines. Results In total, 1,923 sylvatic individuals were collected representing a sampling effort of 751 man-hours. Collected sylvatic triatomines were associated with mammal and bird nests. The 1,219 sampled nests presented an infestation index of 11.9%, a crowding of 13 bugs per infested nest, and a colonization of 80% of the nests. Triatomine abundance was significantly higher in squirrel (Sciurus stramineus) nests located above five meters from ground level and close to the houses. In addition, 8.5% of the 820 examined houses in the same localities were infested with triatomines. There was a significant correlation between R. ecuadoriensis infestation rates found in sylvatic and synanthropic environments within communities (p = 0.012). Parasitological analysis revealed that 64.7% and 15.7% of the sylvatic bugs examined (n = 300) were infected with Trypanosoma cruzi and T. rangeli respectively, and 8% of the bugs presented mixed infections. Conclusions The wide distribution of sylvatic R. ecuadoriensis populations may jeopardize the effectiveness of control campaigns conducted to eliminate domestic populations of this species. Also, the high T. cruzi infection rates found in sylvatic R. ecuadoriensis populations in southern Ecuador could constitute a risk for house re-infestation and persistent long-term Chagas disease transmission in the region. PMID:22243930

Ecological factors related to the widespread distribution of sylvatic Rhodnius ecuadoriensis populations in southern Ecuador.

PubMed

Grijalva, Mario J; Suarez-Davalos, Victoria; Villacis, Anita G; Ocaña-Mayorga, Sofia; Dangles, Olivier

2012-01-13

Chagas disease transmission risk is a function of the presence of triatomines in domestic habitats. Rhodnius ecuadoriensis is one of the main vectors implicated in transmission of Trypanosoma cruzi in Ecuador. This triatomine species is present in domestic, peridomestic and sylvatic habitats in the country. To determine the distribution of sylvatic populations of R. ecuadoriensis and the factors related to this distribution, triatomine searches were conducted between 2005 and 2009 in southern Ecuador. Manual triatomine searches were conducted by skilled bug collectors in 23 communities. Sylvatic searched sites were selected by a) directed sampling, where microhabitats were selected by the searchers and b) random sampling, where sampling points where randomly generated. Domiciliary triatomine searches were conducted using the one man-hour method. Natural trypanosome infection was determined by microscopic examination and PCR. Generalized linear models were used to test the effect of environmental factors on the presence of sylvatic triatomines. In total, 1,923 sylvatic individuals were collected representing a sampling effort of 751 man-hours. Collected sylvatic triatomines were associated with mammal and bird nests. The 1,219 sampled nests presented an infestation index of 11.9%, a crowding of 13 bugs per infested nest, and a colonization of 80% of the nests. Triatomine abundance was significantly higher in squirrel (Sciurus stramineus) nests located above five meters from ground level and close to the houses. In addition, 8.5% of the 820 examined houses in the same localities were infested with triatomines. There was a significant correlation between R. ecuadoriensis infestation rates found in sylvatic and synanthropic environments within communities (p = 0.012). Parasitological analysis revealed that 64.7% and 15.7% of the sylvatic bugs examined (n = 300) were infected with Trypanosoma cruzi and T. rangeli respectively, and 8% of the bugs presented mixed infections. The wide distribution of sylvatic R. ecuadoriensis populations may jeopardize the effectiveness of control campaigns conducted to eliminate domestic populations of this species. Also, the high T. cruzi infection rates found in sylvatic R. ecuadoriensis populations in southern Ecuador could constitute a risk for house re-infestation and persistent long-term Chagas disease transmission in the region.

Phenology largely explains taller grass at successful nests in greater sage-grouse.

PubMed

Smith, Joseph T; Tack, Jason D; Doherty, Kevin E; Allred, Brady W; Maestas, Jeremy D; Berkeley, Lorelle I; Dettenmaier, Seth J; Messmer, Terry A; Naugle, David E

2018-01-01

Much interest lies in the identification of manageable habitat variables that affect key vital rates for species of concern. For ground-nesting birds, vegetation surrounding the nest may play an important role in mediating nest success by providing concealment from predators. Height of grasses surrounding the nest is thought to be a driver of nest survival in greater sage-grouse ( Centrocercus urophasianus ; sage-grouse), a species that has experienced widespread population declines throughout their range. However, a growing body of the literature has found that widely used field methods can produce misleading inference on the relationship between grass height and nest success. Specifically, it has been demonstrated that measuring concealment following nest fate (failure or hatch) introduces a temporal bias whereby successful nests are measured later in the season, on average, than failed nests. This sampling bias can produce inference suggesting a positive effect of grass height on nest survival, though the relationship arises due to the confounding effect of plant phenology, not an effect on predation risk. To test the generality of this finding for sage-grouse, we reanalyzed existing datasets comprising >800 sage-grouse nests from three independent studies across the range where there was a positive relationship found between grass height and nest survival, including two using methods now known to be biased. Correcting for phenology produced equivocal relationships between grass height and sage-grouse nest survival. Viewed in total, evidence for a ubiquitous biological effect of grass height on sage-grouse nest success across time and space is lacking. In light of these findings, a reevaluation of land management guidelines emphasizing specific grass height targets to promote nest success may be merited.

Application of ground penetrating radar in detecting the hazards and risks of termites and ants in soil levees.

PubMed

Yang, Xiuhao; Henderson, Gregg; Mao, Lixin; Evans, Ahmad

2009-08-01

A ground penetrating radar (GPR) technique was used to detect Formosan subterranean termite (Coptotermes formosanus) and red imported fire ant (Solenopsis invicta) hazards and risks (targets) in a soil levee at the London Avenue Canal in New Orleans, LA. To make this assessment, GPR signal scans were examined for features produced by termite or ant activities and potential sources of food and shelter such as nests, tree roots, and voids (tunnels). The total scanned length of the soil levee was 4,125 m. The average velocity and effective depth of the radar penetration was 0.080 m/ns and 0.61 m, respectively. Four hundred twenty-seven targets were identified. Tree roots (38), voids (31), fire ant nests (209), and metal objects (149) were detected, but no Formosan termite carton nests were identified. The lack of identified termite nests may be related to drowning events at the time to the flood. Based on the target density (TD), the two new floodwall and levee sections that were rebuilt or reinforced after they were destroyed by Hurricane Katrina in 2005 were determined to be at low potential risk from termites and ants. A merging target density (MTD) method indicated a high potential risk near one of the breached sections still remains. Foraging and nesting activity of Formosan subterranean termites and red imported fire ants may be a contributory factor to the levee failure at the London Avenue Canal.

Effects of radiomarking on prairie falcons: Attachment failures provide insights about survival

USGS Publications Warehouse

Steenhof, Karen; Bates, Kirk K.; Fuller, Mark R.; Kochert, Michael N.; McKinley, James O.; Lukacs, Paul M.

2006-01-01

From 1999–2002, we attached satellite-received platform transmitter terminals (PTTs) to 40 adult female prairie falcons (Falco mexicanus) on their nesting grounds in the Snake River Birds of Prey National Conservation Area (NCA) in southwest Idaho. We used 3 variations of a backpack harness design that had been used previously on raptors. Each radiomarked falcon also received a color leg band with a unique alphanumeric code. We monitored survival of birds using radiotelemetry and searched for marked birds on their nesting grounds during breeding seasons after marking. Because 6 falcons removed their harnesses during the first year, we were able to compare survival rates of birds that shed PTTs with those that retained them. We describe a harness design that failed prematurely as well as designs that proved successful for long-term PTT attachment. We resighted 21 marked individuals on nesting areas 1–5 years after they were radiomarked and documented 13 mortalities of satellite-tracked falcons. We used a Cormack-Jolly-Seber model to estimate apparent survival probability based on band resighting and telemetry data. Platform transmitter terminals had no short-term effects on falcons or their nesting success during the nesting season they were marked, but birds that shed their transmitters increased their probability of survival. Estimated annual survival for birds that shed their transmitters was 87% compared to 49% for birds wearing transmitters. We discuss possible reasons for differences in apparent survival rates and offer recommendations for future marking of falcons.

Effects of radio marking on prairie falcons: Attachment failures provide insights about survival

USGS Publications Warehouse

Steenhof, Karen; Bates, Kirk K.; Fuller, Mark R.; Kochert, Michael N.; McKinley, J.O.; Lukacs, Paul M.

2006-01-01

From 1999-2002, we attached satellite-received platform transmitter terminals (PTTs) to 40 adult female prairie falcons (Falco mexicanus) on their nesting grounds in the Snake River Birds of Prey National Conservation Area (NCA) in southwest Idaho. We used 3 variations of a backpack harness design that had been used previously on raptors. Each radiomarked falcon also received a color leg band with a unique alphanumeric code. We monitored survival of birds using radiotelemetry and searched for marked birds on their nesting grounds during breeding seasons after marking. Because 6 falcons removed their harnesses during the first year, we were able to compare survival rates of birds that shed PTTs with those that retained them. We describe a harness design that failed prematurely as well as designs that proved successful for long-term PTT attachment. We resighted 21 marked individuals on nesting areas 1-5 years after they were radiomarked and documented 13 mortalities of satellite-tracked falcons. We used a Cormack-Jolly-Seber model to estimate apparent survival probability based on band resighting and telemetry data. Platform transmitter terminals had no short-term effects on falcons or their nesting success during the nesting season they were marked, but birds that shed their transmitters increased their probability of survival. Estimated annual survival for birds that shed their transmitters was 87% compared to 49% for birds wearing transmitters. We discuss possible reasons for differences in apparent survival rates and offer recommendations for future marking of falcons.

Landscape and Local Correlates of Bee Abundance and Species Richness in Urban Gardens.

PubMed

Quistberg, Robyn D; Bichier, Peter; Philpott, Stacy M

2016-03-31

Urban gardens may preserve biodiversity as urban population densities increase, but this strongly depends on the characteristics of the gardens and the landscapes in which they are embedded. We investigated whether local and landscape characteristics are important correlates of bee (Hymenoptera: Apiformes) abundance and species richness in urban community gardens. We worked in 19 gardens in the California central coast and sampled bees with aerial nets and pan traps. We measured local characteristics (i.e., vegetation and ground cover) and used the USGS National Land Cover Database to classify the landscape surrounding our garden study sites at 2 km scales. We classified bees according to nesting type (i.e., cavity, ground) and body size and determined which local and landscape characteristics correlate with bee community characteristics. We found 55 bee species. One landscape and several local factors correlated with differences in bee abundance and richness for all bees, cavity-nesting bees, ground-nesting bees, and different sized bees. Generally, bees were more abundant and species rich in bigger gardens, in gardens with higher floral abundance, less mulch cover, more bare ground, and with more grass. Medium bees were less abundant in sites surrounded by more medium intensity developed land within 2 km. The fact that local factors were generally more important drivers of bee abundance and richness indicates a potential for gardeners to promote bee conservation by altering local management practices. In particular, increasing floral abundance, decreasing use of mulch, and providing bare ground may promote bees in urban gardens. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Breeding ecology of Wandering Tattlers Tringa incana: a study from south-central Alaska

USGS Publications Warehouse

Gill, Robert E.; Tomkovich, Pavel S.; Dementyev, Maksim N.

2015-01-01

Montane-nesting shorebirds are arguably the least studied of the Charadriiformes, owing in part to the remoteness of their breeding areas, low nesting densities, and specialized behaviors. We studied a marked population of the Wandering Tattler Tringa incana, during a three-year period (1997–1999) on nesting grounds in south-central Alaska. Two aspects of our results stand out. First is the previously undescribed preference for tattlers to nest several kilometers removed from pre-nesting feeding areas, mostly in association with both small (kettle) lakes and running water (near small distributaries of major drainages). Second is the apparent use of the study area by cohorts of birds of different breeding status, including (1) local breeders, which defended pre-breeding foraging areas, (2) local non-breeding birds, which remained on the area but were not territorial, and (3) transients that were captured later in the season, but not seen again on the area during the season of capture. We also found that (1) birds tended to nest in clusters despite what appeared to be the ample availability of nesting habitat, (2) they employed an inconspicuous’ nesting strategy whereby neither member of a pair betrayed its presence on the nesting area, and (3) females departed the area during early chick-rearing, leaving males to tend broods.

Importance of individual species of predators on nesting success of ducks in the Canadian prairie pothole region

USGS Publications Warehouse

Johnson, Douglas H.; Sargeant, Alan B.; Greenwood, Raymond J.

1989-01-01

We followed 3094 upland nests of several species of ducks. Clutches in most nests were lost to predation. We related daily nest predation rates to indices of activity of eight egg-eating predators, precipitation during the nesting season, and measures of wetland conditions. Activity indices of red fox (Vulpes vulpes), striped skunk (Mephitis mephitis), and raccoon (Procyon lotor) activity were positively correlated, as were activity indices of coyote (Canis latrans), Franklin's ground squirrel (Spermophilus franklinii), and black-billed magpie (Pica pica). Indices of fox and coyote activity were strongly negatively correlated (r = -0.51), as were those of badger (Taxidea taxus) and skunk (r = -0.46). Nest predation rates in the early part of the breeding season were positively related to indices of fox, American crow (Corvus brachyrhynchos), and badger activity. Predation rates in the latter part of the season were positively related to indices of fox and skunk activity. Predation rates on early-season nests were lower in areas and years in which larger fractions of seasonal wetlands contained water. For late-season nests, a similar relationship held involving semipermanent wetlands. We suspect that the wetland measures, which reflect precipitation during some previous period, also indicate vegetation growth and the abundance of buffer prey, factors that may influence nest predation rates.

Mapping forest canopy gaps using air-photo interpretation and ground surveys

USGS Publications Warehouse

Fox, T.J.; Knutson, M.G.; Hines, R.K.

2000-01-01

Canopy gaps are important structural components of forested habitats for many wildlife species. Recent improvements in the spatial accuracy of geographic information system tools facilitate accurate mapping of small canopy features such as gaps. We compared canopy-gap maps generated using ground survey methods with those derived from air-photo interpretation. We found that maps created from high-resolution air photos were more accurate than those created from ground surveys. Errors of omission were 25.6% for the ground-survey method and 4.7% for the air-photo method. One variable of inter est in songbird research is the distance from nests to gap edges. Distances from real and simulated nests to gap edges were longer using the ground-survey maps versus the air-photo maps, indicating that gap omission could potentially bias the assessment of spatial relationships. If research or management goals require location and size of canopy gaps and specific information about vegetation structure, we recommend a 2-fold approach. First, canopy gaps can be located and the perimeters defined using 1:15,000-scale or larger aerial photographs and the methods we describe. Mapped gaps can then be field-surveyed to obtain detailed vegetation data.

Raptor nesting near oil and gas development: an overview of key findings and implications for management based on four reports by HawkWatch International

USGS Publications Warehouse

Fuller, Mark R.

2013-01-01

juniper vegetation communities in the Piceance Basin of Colorado, described basic vegetation and landscape characteristics of nests, and offered recommendations about surveying for accipiter hawks in pinyon–juniper landscapes. Please read the HWI reports for details.

Conservation implications when the next predators are known. Chapter 2

Treesearch

Frank R., III Thompson; Christine A. Ribic

2012-01-01

Conservation and management of passerines has largely focused on habitat manipulation or restoration because the natural communities on which these birds depend have been destroyed and fragmented. However, productivity is another important aspect of avian conservation, and nest predation can be a large source of nesting mortality for passerines. Recent studies using...

A comparison of the seasonal movements of tiger sharks and green turtles provides insight into their predator-prey relationship.

PubMed

Fitzpatrick, Richard; Thums, Michele; Bell, Ian; Meekan, Mark G; Stevens, John D; Barnett, Adam

2012-01-01

During the reproductive season, sea turtles use a restricted area in the vicinity of their nesting beaches, making them vulnerable to predation. At Raine Island (Australia), the highest density green turtle Chelonia mydas rookery in the world, tiger sharks Galeocerdo cuvier have been observed to feed on green turtles, and it has been suggested that they may specialise on such air-breathing prey. However there is little information with which to examine this hypothesis. We compared the spatial and temporal components of movement behaviour of these two potentially interacting species in order to provide insight into the predator-prey relationship. Specifically, we tested the hypothesis that tiger shark movements are more concentrated at Raine Island during the green turtle nesting season than outside the turtle nesting season when turtles are not concentrated at Raine Island. Turtles showed area-restricted search behaviour around Raine Island for ∼3-4 months during the nesting period (November-February). This was followed by direct movement (transit) to putative foraging grounds mostly in the Torres Straight where they switched to area-restricted search mode again, and remained resident for the remainder of the deployment (53-304 days). In contrast, tiger sharks displayed high spatial and temporal variation in movement behaviour which was not closely linked to the movement behaviour of green turtles or recognised turtle foraging grounds. On average, tiger sharks were concentrated around Raine Island throughout the year. While information on diet is required to determine whether tiger sharks are turtle specialists our results support the hypothesis that they target this predictable and plentiful prey during turtle nesting season, but they might not focus on this less predictable food source outside the nesting season.

Migratory corridors of adult female Kemp’s ridley turtles in the Gulf of Mexico

USGS Publications Warehouse

Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Rubio, Cynthia; Sartain-Iverson, Autumn R.; Pena, Jaime; Gamez, Daniel Gomez; Gonzales Diaz Miron, Raul de Jesus; Burchfield, Patrick M.; Martinez, Hector J.; Ortiz, Jaime

2016-01-01

For many marine species, locations of migratory pathways are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to define the migratory corridor used by Kemp's ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. The turtles were tagged after nesting at Padre Island National Seashore, Texas, USA from 1997 to 2014 (PAIS; n = 80); Rancho Nuevo, Tamaulipas, Mexico from 2010 to 2011 (RN; n = 14); Tecolutla, Veracruz, Mexico from 2012 to 2013 (VC; n = 13); and Gulf Shores, Alabama, USA during 2012 (GS; n = 1). The migratory corridor lies in nearshore Gulf of Mexico waters in the USA and Mexico with mean water depth of 26 m and a mean distance of 20 km from the nearest mainland coast. Migration from the nesting beach is a short phenomenon that occurs from late-May through August, with a peak in June. There was spatial similarity of post-nesting migratory pathways for different turtles over a 16 year period. Thus, our results indicate that these nearshore Gulf waters represent a critical migratory habitat for this species. However, there is a gap in our understanding of the migratory pathways used by this and other species to return from foraging grounds to nesting beaches. Therefore, our results highlight the need for tracking reproductive individuals from foraging grounds to nesting beaches. Continued tracking of adult females from PAIS, RN, and VC nesting beaches will allow further study of environmental and bathymetric components of migratory habitat and threats occurring within our defined corridor. Furthermore, the existence of this migratory corridor in nearshore waters of both the USA and Mexico demonstrates that international cooperation is necessary to protect essential migratory habitat for this imperiled species.

A Comparison of the Seasonal Movements of Tiger Sharks and Green Turtles Provides Insight into Their Predator-Prey Relationship

PubMed Central

Fitzpatrick, Richard; Thums, Michele; Bell, Ian; Meekan, Mark G.; Stevens, John D.; Barnett, Adam

2012-01-01

During the reproductive season, sea turtles use a restricted area in the vicinity of their nesting beaches, making them vulnerable to predation. At Raine Island (Australia), the highest density green turtle Chelonia mydas rookery in the world, tiger sharks Galeocerdo cuvier have been observed to feed on green turtles, and it has been suggested that they may specialise on such air-breathing prey. However there is little information with which to examine this hypothesis. We compared the spatial and temporal components of movement behaviour of these two potentially interacting species in order to provide insight into the predator-prey relationship. Specifically, we tested the hypothesis that tiger shark movements are more concentrated at Raine Island during the green turtle nesting season than outside the turtle nesting season when turtles are not concentrated at Raine Island. Turtles showed area-restricted search behaviour around Raine Island for ∼3–4 months during the nesting period (November–February). This was followed by direct movement (transit) to putative foraging grounds mostly in the Torres Straight where they switched to area-restricted search mode again, and remained resident for the remainder of the deployment (53–304 days). In contrast, tiger sharks displayed high spatial and temporal variation in movement behaviour which was not closely linked to the movement behaviour of green turtles or recognised turtle foraging grounds. On average, tiger sharks were concentrated around Raine Island throughout the year. While information on diet is required to determine whether tiger sharks are turtle specialists our results support the hypothesis that they target this predictable and plentiful prey during turtle nesting season, but they might not focus on this less predictable food source outside the nesting season. PMID:23284819

NASA airborne laser altimetry and ICESat-2 post-launch data validation

NASA Astrophysics Data System (ADS)

Brunt, K. M.; Neumann, T.; Studinger, M.; Hawley, R. L.; Markus, T.

2016-12-01

A series of NASA airborne lidars have made repeated surveys over an 11,000-m ground-based kinematic GPS traverse near Summit Station, Greenland. These ground-based data were used to assess the surface elevation bias and measurement precision of two airborne laser altimeters: Airborne Topographic Mapper (ATM) and Land, Vegetation, and Ice Sensor (LVIS). Data from the ongoing monthly traverses allowed for the assessment of 8 airborne lidar campaigns; elevation biases for these altimeters were less than 12.2 cm, while assessments of surface measurement precision were less than 9.1 cm. Results from the analyses of the Greenland ground-based GPS and airborne lidar data provide guidance for validation strategies for Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) elevation and elevation-change data products. Specifically, a nested approach to validation is required, where ground-based GPS data are used to constrain the bias and measurement precision of the airborne lidar data; airborne surveys can then be designed and conducted on longer length-scales to provide the amount of airborne data required to make more statistically meaningful assessments of satellite elevation data. This nested validation approach will continue for the ground-traverse in Greenland; further, the ICESat-2 Project Science Office has plans to conduct similar coordinated ground-based and airborne data collection in Antarctica.

KSC-04pd0879

NASA Image and Video Library

2004-04-16

KENNEDY SPACE CENTER, FLA. - Two fledgling ospreys occupy a nest near the NASA-KSC News Center, across from the Vehicle Assembly Building. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

Inter-seasonal maintenance of individual nest site preferences in hawksbill sea turtles.

PubMed

Kamel, Stephanie J; Mrosovsky, N

2006-11-01

Within a single population of hawksbill sea turtles (Eretmochelys imbricata), we found a behavioral polymorphism for maternal nest site choice with respect to beach microhabitat characteristics. Some females preferred to nest in littoral forest and in places with overstory vegetation cover, and others preferred to nest in more open, deforested areas. Nest site choice was consistent within and between nesting seasons two years apart. This was not a result of females simply returning to the same location along the shoreline; beach sections used by individual turtles varied between seasons. Nest site choice was not influenced by changes in beach environment (e.g., beach width and foliage cover) or by changes in females' reproductive output (e.g., clutch size), suggesting that fidelity to particular microhabitats is a major determinant of the observed nesting patterns. Because hawksbills exhibit temperature-dependent sex determination, if the behavioral polymorphism in nest site choice has a genetic basis, as is plausible, then this would have implications for sex ratio evolution and offspring survival. By taking an individual-based approach to the study of maternal behavior we reveal previously overlooked individual variation and hope to provide some impetus for more detailed studies of nest site choice.

Factor determining prochard nest predation along a wetland gradient

USGS Publications Warehouse

Albrecht, T.; Horak, D.; Kreisinger, J.; Weidinger, K.; Klvana, P.; Michot, T.C.

2006-01-01

Waterfowl management on breeding grounds focuses on improving nest success, but few studies have compared waterfowl nest success and factors affecting nest survival along a wetland gradient and simultaneously identified nest predators. We monitored nests (n = 195) of common pochards (Aythya ferina) in Trebon Basin Biosphere Reserve, Czech Republic, during 1999-2002. Daily nest survival rates (DSRs, logistic-exposure) declined from island (0.985, 95% confidence interval, 0.978-0.991) to overwater (0.962, 0.950-0.971) and terrestrial (0.844, 0.759-0.904) nests. The most parsimonious model for DSRs included habitat class (DSRs: island > overwater > terrestrial) and nest visibility. Nest survival was improved by reduced nest visibility, increased water depth, and increased distance from the nest to habitat edge in littoral habitats. On islands, nest success increased with advancing date and increased distance to open water. A model of constant nest survival best explained the data for terrestrial nests. There were no observer effects on DSRs in any habitat. In 2003, artificial nests (n = 180; 120 contained a wax-filled egg) were deployed on study plots. The model that best explained variation in DSRs for artificial nests included only 1 variable: habitat class (DSRs: island ??? overwater > terrestrial). Mammalian predation of artificial nests (by foxes [Vulpes vulpes] and martens [Martes spp.]) was more likely in terrestrial habitats than in littoral habitats or on islands. By contrast, corvids and marsh harriers (Circus aeruginosus) prevailed among predators of overwater and island nests. Our data indicate that artificial islands and wide strips of littoral vegetation may represent secure breeding habitats for waterfowl because those habitats allow nests to be placed in areas that are not accessible to, or that are avoided by, mammalian predators. Management actions should be aimed at preserving these habitats. This, along with creation of new artificial islands, could help to enhance breeding productivity of pochards and possibly other waterfowl species inhabiting man-made ponds.

Adaptive nest clustering and density-dependent nest survival in dabbling ducks

USGS Publications Warehouse

Ringelman, Kevin M.; Eadie, John M.; Ackerman, Joshua T.

2014-01-01

Density-dependent population regulation is observed in many taxa, and understanding the mechanisms that generate density dependence is especially important for the conservation of heavily-managed species. In one such system, North American waterfowl, density dependence is often observed at continental scales, and nest predation has long been implicated as a key factor driving this pattern. However, despite extensive research on this topic, it remains unclear if and how nest density influences predation rates. Part of this confusion may have arisen because previous studies have studied density-dependent predation at relatively large spatial and temporal scales. Because the spatial distribution of nests changes throughout the season, which potentially influences predator behavior, nest survival may vary through time at relatively small spatial scales. As such, density-dependent nest predation might be more detectable at a spatially- and temporally-refined scale and this may provide new insights into nest site selection and predator foraging behavior. Here, we used three years of data on nest survival of two species of waterfowl, mallards and gadwall, to more fully explore the relationship between local nest clustering and nest survival. Throughout the season, we found that the distribution of nests was consistently clustered at small spatial scales (˜50–400 m), especially for mallard nests, and that this pattern was robust to yearly variation in nest density and the intensity of predation. We demonstrated further that local nest clustering had positive fitness consequences – nests with closer nearest neighbors were more likely to be successful, a result that is counter to the general assumption that nest predation rates increase with nest density.

Repeated use of an abandoned vehicle by nesting Turkey vultures (Cathartes aura)

USGS Publications Warehouse

Igl, L.D.; Peterson, S.L.

2010-01-01

Turkey Vultures (Cathartes aura) lay their eggs on an existing substrate in the dark recesses of a variety of natural sites (Kirk and Mossman 1998). Although an important requirement of Turkey Vulture nest-site selection is isolation from human disturbances (Kirk and Mossman 1998), their nests have been reported in abandoned buildings since at least the early 1800s (Nuttall 1832). Depopulation of rural areas in North America in recent decades has resulted in many abandoned buildings within the Turkey Vulture's breeding range (Peck 2003). Increased use of abandoned buildings by nesting Turkey Vultures has been implicated in the species' recent northward range expansion (Peck 2003, Nelson et al. 2005, Houston et al. 2007). Although abandoned or inoperative vehicles also are widespread in rural areas, we found no published literature documenting Turkey Vultures' use of these potential nest sites. Herein, we summarize the first documented incidence of a Turkey Vulture nesting in an abandoned vehicle.

Life history attributes of Arizona Grasshopper Sparrow (Ammodramus savannarum ammolegus) and comparisons with other North American subspecies

USGS Publications Warehouse

Ruth, Janet M.

2017-01-01

Ammodramus savannarum ammolegus—commonly referred to as the Arizona Grasshopper Sparrow—occurs in the desert and plains grasslands of southeastern Arizona, southwestern New Mexico, and northern Sonora, Mexico. Although a subspecies of conservation concern, this is the first intensive study of its life history and breeding ecology, providing baseline data and facilitating comparisons with other North American Grasshopper Sparrow subspecies. Specifically, I found A. s. ammolegus males generally weighed less than other subspecies (16.0 ± 0.8 g) but with intermediate exposed culmen length (11.6 ± 0.5 mm) and wing chord length similar to the other two migratory subspecies (62.7 ± 1.5 mm). Territory size for A. s. ammolegus was 0.72 ± 0.37 ha, with some variation between sites and among years, possibly indicating variation in habitat quality across spatial and temporal scales. The return rate for A. s. ammolegus males was 39.2%. Nest initiation for A. s. ammolegus was early to mid-July after the monsoons had begun. Domed nests were constructed on the ground, primarily under native bunch grasses, and frequently with a tunnel extending beyond the nest rim, with nest openings oriented north. Clutch size was 3.97 ± 0.68, with no evidence of Brown-headed Cowbird (Molothrus ater) nest parasitism. Extreme climate factors in the arid Southwest may have affected the life history and morphology of A. s. ammolegus as compared to other subspecies, influencing body size and mass, culmen length, breeding phenology, and nest orientation. Other geographic variation occurred in return rates, clutch size, and nest parasitism rates. The baseline data for A. s. ammolegus obtained in this study will inform future taxonomic and ecological studies as well as conservation planning. Comparisons of A. s. ammolegus morphometrics with those of other subspecies will assist field biologists in distinguishing among subspecies where they overlap, especially on wintering grounds.

Nesting biology of Lesser Canada Geese, Branta canadensis parvipes, along the Tanana River, Alaska

USGS Publications Warehouse

Ely, Craig R.; Pearce, J.M.; Ruess, Roger W.

2008-01-01

Lesser Canada Geese (Branta canadensis parvipes) are widespread throughout interior regions of Alaska and Canada, yet there have been no published studies documenting basic aspects of their nesting biology. We conducted a study to determine reproductive parameters of Lesser Canada Geese nesting along the Tanana River near the city of Fairbanks, in interior Alaska. Fieldwork was conducted in May of 2003, and consisted of locating nests along the riparian corridor between Fairbanks and Northpole, Alaska. Nests were found on gravel islands and shore habitats along the Tanana River, and were most commonly observed among driftwood logs associated with patches of alder (Alnus spp.) and willow (Salix spp.). Peak of nest initiation was 3-8 May, with a range from 27 April to 20 May; renesting was likely. Clutches ranged in size from 2 to 7 eggs and averaged 4.6 eggs. There was a negative correlation between clutch size and date of nest initiation. Egg size (mean mass = 128 g) was similar to other medium-sized Canada Geese. A positive correlation between egg size and clutch size was likely related to female age. Nineteen of 28 nests (68%) were active when visited; nests located on islands with nesting Mew Gulls (Larus canus) were more likely to be active than nests located elsewhere. Evidence at nest sites implicated Bald Eagles (Haliaeetus leucocephalus) and Red Foxes (Vulpes vulpes) as nest predators.

Monitoring arctic habitat and goose production by satellite imagery

USGS Publications Warehouse

Reeves, H.M.; Cooch, F.G.; Munro, R.E.

1976-01-01

Spacecraft imagery, especially from the National Atmospheric and Oceanic Administration's Improved TIROS (Television Infra-Red Observational Satellite) Operational Satellites, permits timely evaluations of snow and ice conditions encountered by arctic nesting geese. Imagery from the TIROS satellite for 5 wide]y scattered locations in arctic North America was obtained for three 3-day intervals in June 1973 and 1974. These pictures were used to expand fragmentary habitat data available from ground observations. Late disappearance of snow and ice may prevent or retard nesting effort and reproductive success. Our immediate aim is to recognize years of catastrophic or very good production; however, supporting information from ground studies, LANDSAT imagery, analyses of banding data, and studies of age ratios in popu]ations and harvests eventua

Bee species-specific nesting material attracts a generalist parasitoid: implications for co-occurring bees in nest box enhancements.

PubMed

Macivor, J Scott; Salehi, Baharak

2014-08-01

Artificial nests (e.g., nest boxes) for bees are increasingly being used to contribute to nesting habitat enhancement for bees that use preexisting cavities to provision brood. They usually incorporate additional nesting materials that vary by species. Cavity-nesting bees are susceptible to brood parasitoids that recognize their host(s) using visual and chemical cues. Understanding the range of cues that attract parasitoids to bee nests, including human-made analogues, is important if we wish to control parasitism and increase the potential value of artificial nests as habitat-enhancement strategies. In this study, we investigated the cues associated with the orientation of the generalist brood parasitoid Monodontomerus obscurus Westwood (Hymenoptera: Torymidae) to the nests of a common cavity-nesting resin bee Megachile campanulae (Robertson) (Megachilidae). The parasitoids were reared from previously infested M. campanulae brood cells and placed into choice trials where they were presented with pairs of different nest material cues. Among different materials tested, we found that Mo. obscurus was most attracted to fresh resin collected directly from Pinus strobus trees followed by previously used resin collected from the bee nest. The parasitoid also attacked other bee species in the same nest boxes, including those that do not use resin for nesting. Our findings suggest that M. campanulae could act as a magnet, drawing parasites away from other bee hosts co-occurring in nest boxes, or, as an attractant of Mo. obscurus to nest boxes, increasing attacks on co-occurring host bee species, potentially undermining bee diversity enhancement initiatives.

KSC-04pd1147

NASA Image and Video Library

2004-05-14

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings exercises its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04pd1146

NASA Image and Video Library

2004-05-14

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings exercises its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04pd0953

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - Against the backdrop of the American flag, painted on the side of the Vehicle Assembly Building, an osprey checks its fledglings in the nest. The young bird seen is one of three hatched this season. The osprey nest sits atop a speaker in the parking lot of the NASA KSC News Center. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-03pd0950

NASA Image and Video Library

2003-04-02

KENNEDY SPACE CENTER, FLA. -- While the female osprey eats fish brought by her mate, the male guards the nest, recently constructed on a speaker in the lower parking lot of the Press Site. Eggs have been sighted in the nest. The NASA logo seen in the background is on the nearby Vehicle Assembly Building. Known as a fish hawk, the osprey selects sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and surrounding Merritt Island National Wildlife Refuge.

KSC-04pd1144

NASA Image and Video Library

2004-05-14

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings spreads its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04pd1145

NASA Image and Video Library

2004-05-14

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings spreads its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04PD-1145

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings spreads its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04PD-1146

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings exercises its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04PD-1147

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings exercises its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04PD-1144

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- One of three osprey fledglings spreads its wings, anticipating flight. The nest is in the NASA News Center parking lot, across from the Vehicle Assembly Building, with its 209-foot-high American flag painted on the south side. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons.

KSC-04PD-0953

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Against the backdrop of the American flag, painted on the side of the Vehicle Assembly Building, an osprey checks its fledglings in the nest. The young bird seen is one of three hatched this season. The osprey nest sits atop a speaker in the parking lot of the NASA KSC News Center. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

MIGRATION PATTERNS, USE OF STOPOVER AREAS, AND AUSTRAL SUMMER MOVEMENTS OF SWAINSON’S HAWKS

PubMed Central

Kochert, Michael N.; Fuller, Mark R.; Schueck, Linda S.; Bond, Laura; Bechard, Marc J.; Woodbridge, Brian; Holroyd, Geoff; Martell, Mark; Banasch, Ursula

2015-01-01

From 1995–1998, we tracked movements of adult Swainson’s Hawks (Buteo swainsoni) using satellite telemetry to characterize migration, important stopover areas, and austral summer movements. We tagged 46 hawks from July - September on their nesting grounds in seven U.S. states and two Canadian provinces. Swainson’s Hawks basically followed three routes south on a broad front, converged along the east coast of central Mexico, and followed a concentrated corridor to a communal austral summer area in central Argentina. North of 20° N, southward and northward tracks differed little for individuals from east of the Continental Divide but differed greatly (up to 1700 km) for individuals from west of the Continental Divide. Hawks left the breeding grounds mid-August to mid-October; departure dates did not differ by location, year, or sex. South migration lasted 42 to 98 days, and north migration took 51 to 82 days. On south migration, 36% of the Swainson’s Hawks departed the nesting grounds nearly 3 weeks earlier than the other radio marked hawks and made stopovers 9.0 – 26.0 days long in seven separate areas, mainly in the southern Great Plains, southern Arizona and New Mexico, and north-central Mexico. The austral period lasted 76 to 128 days. All Swainson’s Hawks used a core area in central Argentina within 23% of the 738800 km2 austral summer range where they frequently moved long distances (up to 1600 km). Conservation of Swainson’s Hawks must be an international effort that considers habitats used during nesting and non-nesting seasons including migration stopovers. PMID:26380528

Florida Harvester Ant Nest Architecture, Nest Relocation and Soil Carbon Dioxide Gradients

PubMed Central

Tschinkel, Walter R.

2013-01-01

Colonies of the Florida harvester ant, Pogonomyrmex badius, excavate species-typical subterranean nests up the 3 m deep with characteristic vertical distribution of chamber area/shape, spacing between levels and vertical arrangement of the ants by age and brood stage. Colonies excavate and occupy a new nest about once a year, and doing so requires that they have information about the depth below ground. Careful excavation and mapping of vacated and new nests revealed that there was no significant difference between the old and new nests in any measure of nest size, shape or arrangement. Colonies essentially built a replicate of the just-vacated nest (although details differed), and they did so in less than a week. The reason for nest relocation is not apparent. Tschinkel noted that the vertical distribution of chamber area, worker age and brood type was strongly correlated to the soil carbon dioxide gradient, and proposed that this gradient serves as a template for nest excavation and vertical distribution. To test this hypothesis, the carbon dioxide gradient of colonies that were just beginning to excavate a new nest was eliminated by boring 6 vent holes around the forming nest, allowing the soil CO2 to diffuse into the atmosphere and eliminating the gradient. Sadly, neither the nest architecture nor the vertical ant distribution of vented nests differed from either unvented control or from their own vacated nest. In a stronger test, workers excavated a new nest under a reversed carbon dioxide gradient (high concentration near the surface, low below). Even under these conditions, the new and old nests did not differ significantly, showing that the soil carbon dioxide gradient does not serve as a template for nest construction or vertical worker distribution. The possible importance of soil CO2 gradients for soil-dwelling animals is discussed. PMID:23555829

KSC-04pd1258

NASA Image and Video Library

2004-06-10

KENNEDY SPACE CENTER, FLA. - An osprey stares intently at prey as it extends its talons. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground, often near water. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-04PD-1258

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. An osprey stares intently at prey as it extends its talons. Known as a fish hawk, ospreys often can be seen flying overhead with a fish in their talons. Fish are their sole source of food. Ospreys select nesting sites of opportunity, from trees and telephone poles to rocks or even flat ground, often near water. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

Head-started Kemp’s ridley turtle (Lepidochelys kempii) nest recorded in Florida: Possible implications

USGS Publications Warehouse

Shaver, Donna J.; Lamont, Margaret M.; Maxwell, Sharon; Walker, Jennifer Shelby; Dillingham, Ted

2016-01-01

A head-started Kemp’s ridley sea turtle (Lepidochelys kempii) was documented nesting on South Walton Beach, Florida on 25 May 2015. This record supports the possibility that exposure to Florida waters after being held in captivity through 1–3 yrs of age during the head-starting process may have influenced future nest site selection of this and perhaps other Kemp’s ridley turtles. Such findings could have important ramifications for marine water experimentation and release site selection for turtles that have been reared in captivity.

Energy dynamics, foraging ecology, and behavior of prenesting greater white-fronted geese

USGS Publications Warehouse

Budeau, D.A.; Ratti, John T.; Ely, Craig R.

1991-01-01

We collected greater white-fronted geese (Anser albifrons frontalis) on their nesting grounds on the Yukon-Kuskokwim Delta, Alaska, when they arrived and again before incubation during 1986 and 1987. Body mass, water content, crude fat, and crude protein increased in female geese between arrival and incubation onset in 1986 and 1987 (P = 0.0001, 0.0002, 0.0329, and 0.0003, respectively). Body mass of male geese during prenesting did not change, but total fat content decreased by about 30%. Crude protein of males was different between years (P = 0.0014). Female geese spent more time feeding than did males (P < 0.001). Primary foods during the prenesting period were pendent grass (Arctophila fulva) shoots and arrowgrass (Triglochin palustris) bulbs. Gizzard contents and orifice staining indicated crowberries (Empetrum nigrum) also were consumed. Of the commonly consumed food items, arrowgrass bulbs had the greatest protein content (21%), and crowberries had the greatest lipid content (10%). Unlike other medium-sized, northern-nesting geese, food (energy) acquired on the nesting grounds by white-fronted geese before incubation increased endogenous reserves necessary for reproduction.

Nests, eggs, and nestlings of the Restinga Antwren Formicivora littoralis (Aves: Thamnophilidae).

PubMed

Chaves, Flávia G; Vecchi, Maurício B; Laurindo, Thiago F S; Alves, Maria Alice S

2013-01-01

We describe the nest, eggs, and nestlings of the Restinga Antwren (Formicivora littoralis), an endangered bird of Restinga ecosystem (sandy coastal plain vegetation) that is endemic to Rio de Janeiro state. Twelve nests were found at the edges of trails or natural gaps at Massambaba Restinga region, in different supporting plants and heights from the ground (X ± SD 1.27 ± 0.97 m, range 0.27 to 3.45 m). Nests were cup-shaped and were in horizontal forks attached to branches at three to five points with whitish, soft, and thin cotton-like vegetable fiber. The nests' cup shape and measurements were similar to congeneric species, but nest material was different. Eggs were white with brown spots concentrated on the large end or around the middle, giving the appearance of a rough brown ring. Their mean (± SD) minimum diameter was 13.1 ± 0.34 mm, with maximum diameter of 18.0 ± 0.38 mm, and mass of 1.7 ± 0.18 g (n = 8). We found two nestlings completely naked on their first day after hatching.

Predator removal and nesting waterbird success at San Francisco Bay, California

USGS Publications Warehouse

Meckstroth, A.M.; Miles, A.K.

2005-01-01

The efficacy of long-term predator removal in urbanized areas is poorly understood. The impact of predation on ground-nesting waterbirds, as well as predator abundance and composition in predator removal versus non-removal or reference sites were examined at South San Francisco Bay. The success of natural nests and predator activity was monitored using track plates, trip cameras, wire haircatchers and simulated nests. Removal sites had higher nest densities, but lower hatching success than reference sites. Predator composition and abundance were not different at the removal and reference sites for any predator other than feral Cat (Felis domesticus). Striped Skunk (Mephitis mephitis) comprised the majority (84%) of predators removed, yet remained the most abundant predators in removal and reference sites. Urban environments provide supplemental food that may influence skunks and other nest predators to immigrate into vacancies created by predator removal. Based on the findings from this study, predator removal should be applied intensively over a larger geographic area in order to be a viable management strategy for some mammalian species in urbanized areas.

Evolution of nesting height in an endangered Hawaiian forest bird in response to a non-native predator.

PubMed

Vanderwerf, Eric A

2012-10-01

The majority of bird extinctions since 1800 have occurred on islands, and non-native predators have been the greatest threat to the persistence of island birds. Island endemic species often lack life-history traits and behaviors that reduce the probability of predation and they can become evolutionarily trapped if they are unable to adapt, but few studies have examined the ability of island species to respond to novel predators. The greatest threat to the persistence of the Oahu Elepaio (Chasiempis ibidis), an endangered Hawaiian forest bird, is nest predation by non-native black rats (Rattus rattus). I examined whether Oahu Elepaio nest placement has changed at the individual and population levels in response to rat predation by measuring nest height and determining whether each nest produced offspring from 1996 to 2011. Average height of Oahu Elepaio nests increased 50% over this 16-year period, from 7.9 m (SE 1.7) to 12.0 m (SE 1.1). There was no net change in height of sequential nests made by individual birds, which means individual elepaios have not learned to place nests higher. Nests ≤3 m off the ground produced offspring less often, and the proportion of such nests declined over time, which suggests that nest-building behavior has evolved through natural selection by predation. Nest success increased over time, which may increase the probability of long-term persistence of the species. Rat control may facilitate the evolution of nesting height by slowing the rate of population decline and providing time for this adaptive response to spread through the population. ©2012 Society for Conservation Biology.

Nest-site selection and nest success of an Arctic-breeding passerine, Smith's Longspur, in a changing climate

USGS Publications Warehouse

McFarland, Heather R.; Kendall, Steve J.; Powell, Abby

2017-01-01

Despite changes in shrub cover and weather patterns associated with climate change in the Arctic, little is known about the breeding requirements of most passerines tied to northern regions. We investigated the nesting biology and nest habitat characteristics of Smith's Longspurs (Calcarius pictus) in 2 study areas in the Brooks Range of Alaska, USA. First, we examined variation in nesting phenology in relation to local temperatures. We then characterized nesting habitat and analyzed nest-site selection for a subset of nests (n = 86) in comparison with paired random points. Finally, we estimated the daily survival rate of 257 nests found in 2007–2013 with respect to both habitat characteristics and weather variables. Nest initiation was delayed in years with snow events, heavy rain, and freezing temperatures early in the breeding season. Nests were typically found in open, low-shrub tundra, and never among tall shrubs (mean shrub height at nests = 26.8 ± 6.7 cm). We observed weak nest-site selection patterns. Considering the similarity between nest sites and paired random points, coupled with the unique social mating system of Smith's Longspurs, we suggest that habitat selection may occur at the neighborhood scale and not at the nest-site scale. The best approximating model explaining nest survival suggested a positive relationship with the numbers of days above 21°C that an individual nest experienced; there was little support for models containing habitat variables. The daily nest survival rate was high (0.972–0.982) compared with that of most passerines in forested or grassland habitats, but similar to that of passerines nesting on tundra. Considering their high nesting success and ability to delay nest initiation during inclement weather, Smith's Longspurs may be resilient to predicted changes in weather regimes on the breeding grounds. Thus, the greatest threat to breeding Smith's Longspurs associated with climate change may be the loss of low-shrub habitat types, which could significantly change the characteristics of breeding areas.

Breeding loggerhead marine turtles Caretta caretta in Dry Tortugas National Park, USA, show high fidelity to diverse habitats near nesting beaches

USGS Publications Warehouse

Hart, Kristen M.; Zawada, David G.; Sartain-Iverson, Autumn R.; Fujisaki, Ikuko

2016-01-01

We used satellite telemetry to identify in-water habitat used by individuals in the smallest North-west Atlantic subpopulation of adult nesting loggerhead turtles Caretta caretta during the breeding season. During 2010, 2011 and 2012 breeding periods, a total of 20 adult females used habitats proximal to nesting beaches with various levels of protection within Dry Tortugas National Park. We then used a rapid, high-resolution, digital imaging system to map habitat adjacent to nesting beaches, revealing the diversity and distribution of available benthic cover. Turtle behaviour showing measurable site-fidelity to these diverse habitats has implications for managing protected areas and human activities within them. Protecting diverse benthic areas adjacent to loggerhead turtle nesting beaches here and elsewhere could provide benefits for overall biodiversity conservation.

Populations and habitat relationships of Piute ground squirrels in southwest Idaho

USGS Publications Warehouse

Steenhof, Karen; Yensen, Eric; Kochert, Michael N.; Gage, K.

2006-01-01

Piute ground squirrels (Spermophilus mollis idahoensis) are normally above ground from late January until late June or early July in the Snake River Birds of Prey National Conservation Area in southwestern Idaho. In 2002 they were rarely seen above ground after early May. Because of the ecological importance of ground squirrels for nesting raptors and other species, we sought to determine the reasons for their early disappearance. We sampled 12 sites from January 2003 through March 2003 to determine if a population crash had occurred in 2002. Tests indicated that Piute ground squirrels had not been exposed to plague within the past year. The presence of yearlings in the population indicated that squirrels reproduced in 2002 and that at least some yearlings survived the winter. Both yearling and adult squirrels appeared to be reproducing at or above normal rates in 2003. The most plausible explanation for the early disappearance of Piute ground squirrels in 2002 is that squirrels entered seasonal torpor early in response to a late spring drought. In addition, the breeding chronology of squirrels may have shifted during the past 2 decades in response to climate change and/or habitat alteration. Shrub habitats provide a more favorable and stable environment for squirrels than grass habitats. Squirrel abundance was higher on live-trapping grids with sagebrush than on grids dominated by grass, and squirrel masses were higher at sites dominated by shrubs and Sandberg bluegrass (Poa secunda). Densities in big sagebrush (Artemisia tridentata) were within the ranges reported for earlier years, but densities in grass were lower than previously reported. Low densities at grassland sites in 2003 support other findings that drought affects squirrels in altered grass communities more than those in native shrub habitats. Long-term shifts in ground squirrel breeding chronology may have implications for raptors that depend on them for food.

Nested variant of the method of moments of coupled cluster equations for vertical excitation energies and excited-state potential energy surfaces.

PubMed

Kowalski, Karol

2009-05-21

In this article we discuss the problem of proper balancing of the noniterative corrections to the ground- and excited-state energies obtained with approximate coupled cluster (CC) and equation-of-motion CC (EOMCC) approaches. It is demonstrated that for a class of excited states dominated by single excitations and for states with medium doubly excited component, the newly introduced nested variant of the method of moments of CC equations provides mathematically rigorous way of balancing the ground- and excited-state correlation effects. The resulting noniterative methodology accounting for the effect of triples is tested using its parallel implementation on the systems, for which iterative CC/EOMCC calculations with full inclusion of triply excited configurations or their most important subset are numerically feasible.

The role of fire and fire management in the invasion of nonnative plants

USGS Publications Warehouse

Merriam, Kyle E.; McGinnis, Thomas W.; Keeley, Jon E.

2004-01-01

Spacecraft imagery, especially from the National Atmospheric and Oceanic Administration's Improved TIROS (Television Infra-Red Observational Satellite) Operational Satellites, permits timely evaluations of snow and ice conditions encountered by arctic nesting geese. Imagery from the TIROS satellite for 5 wide]y scattered locations in arctic North America was obtained for three 3-day intervals in June 1973 and 1974. These pictures were used to expand fragmentary habitat data available from ground observations. Late disappearance of snow and ice may prevent or retard nesting effort and reproductive success. Our immediate aim is to recognize years of catastrophic or very good production; however, supporting information from ground studies, LANDSAT imagery, analyses of banding data, and studies of age ratios in popu]ations and harvests eventua

Female turtles from hot nests: is it duration of incubation or proportion of development at high temperatures that matters?

PubMed

Georges, Arthur

1989-11-01

Mean daily temperature in natural nests of freshwater turtles with temperature-dependent sex determination is known to be a poor predictor of hatchling sex ratios when nest temperatures fluctuate. To account for this, a model was developed on the assumption that females will emerge from eggs when more than half of embryonic development occurs above the threshold temperature for sex determination rather than from eggs that spend more than half their time above the threshold. The model is consistent with previously published data and in particular explains the phenomenon whereby the mean temperature that best distinguishes between male and female nests decreases with increasing variability in nest temperature. The model, if verified by controlled experiments, has important implications for our understanding of temperature-dependent sex determination in natural nests. Both mean nest temperature and "hours spent above the threshold" will be poor predictors of hatchling sex ratios. Studies designed to investigate latitudinal trends and inter-specific differences in the threshold temperature will need to consider latitudinal and inter-specific variation in the magnitude of diel fluctuations in nest temperature, and variation in factors influencing the magnitude of those fluctuations, such as nest depth. Furthermore, any factor that modifies the relationship between developmental rate and temperature can be expected to influence hatchling sex ratios in natural nests, especially when nest temperatures are close to the threshold.

Chapter 7: Breeding and Natal Dispersal, Nest Habitat Loss and Implications for Marbled Murrelet Populations

Treesearch

George J. Divoky; Michael Horton

1995-01-01

Evidence of breeding and natal dispersal in alcids is typically provided by the resightings of banded birds, the establishment of new colonies, and/or evidence of immigration to established colonies. The difficulties in banding, observing, and censusing Marbled Murrelets at nesting areas preclude using any of these methods for this species. Based on the limited number...

Characteristics of aspen infected with heartrot: Implications for cavity-nesting birds

Treesearch

Chris Witt

2010-01-01

Phellinus tremulae is an important fungal decay agent common to aspen and a critical component to the cavity-nesting bird complex found in western aspen stands. Little information exists on the conditions that facilitate infection and spread of P. tremulae in aspen forests. I used Forest Inventory and Analysis (FIA) data to explore the relationships of several tree and...

Breeding biology and success of a reintroduced population of the critically endangered Puaiohi (Myadestes palmeri)

USGS Publications Warehouse

Tweed, E.J.; Foster, J.T.; Woodworth, B.L.; Monahan, W.B.; Kellerman, J.L.; Lieberman, A.

2006-01-01

The ultimate success of reintroduction programs for endangered species depends on the ability of reintroduced animals to breed in the wild. We studied the nesting success and breeding biology of a reintroduced population of Puaiohi (Myadestes palmeri) on the island of Kaua'i, Hawaii. Thirty-four captive-bred Puaiohi were released into the Alaka'i Swamp in 1999-2001 and monitored using radiotelemetry. Ten females and two males paired with wild and other released birds, including one polygynous trio. From March to September, 31 nests were built. Mean clutch size was 2.0 eggs, daily nest survival was 0.97 ± 0.01 (mean ± SE) and overall nest success was 0.40 ± 0.02. We confirmed predation, most probably by rats (Rattus spp.), as the greatest cause of nest failure, occurring at 38% of active nests with known fates, and causing the death of two nesting adult females. Ground-based rodent control proved ineffective at protecting nest attempts. Successful nests fledged an average of 1.4 young each (n = 10), and 85% of fledglings survived at least two weeks. Importantly, breeding behavior and success were comparable to those of wild Puaiohi. This is the first record of breeding in the wild from captive-bred endangered Hawaiian passerines. The ability of captive-bred Puaiohi to survive and breed successfully in the wild bodes well for future releases of this and other endangered passerines, but high predation rates on nests and nesting females highlights the importance of maintaining and restoring safe habitat for recovery.

Thermal fluctuation within nests and predicted sex ratio of Morelet's Crocodile.

PubMed

Escobedo-Galván, Armando H; López-Luna, Marco A; Cupul-Magaña, Fabio G

2016-05-01

Understanding the interplay between thermal variations and sex ratio in reptiles with temperature-dependent sex determination is the first step for developing long-term conservation strategies. In case of crocodilians, the information is fragmentary and insufficient for establishing a general framework to consider how thermal fluctuation influence sex determination under natural conditions. The main goal of this study was to analyze thermal variation in nests of Crocodylus moreletii and to discuss the potential implications for predicting offspring sex ratio. The study was carried out at the Centro de Estudios Tecnológicos del Mar N° 2 and at the Sistemas Productivos Cocodrilo, Campeche, Mexico. Data was collected in the nesting season of Morelet's Crocodiles during three consecutive seasons (2007-2009). Thermal fluctuations for multiple areas of the nest chamber were registered by data loggers. We calculate the constant temperature equivalent based on thermal profiles among nests to assess whether there are differences between the nest temperature and its equivalent to constant temperature. We observed that mean nest temperature was only different among nests, while daily thermal fluctuations vary depending on the depth position within the nest chamber, years and nests. The constant temperature equivalent was different among and within nests, but not among survey years. We observed differences between constant temperature equivalent and mean nest temperature both at the top and in the middle of the nest cavities, but were not significantly different at the bottom of nest cavities. Our results enable examine and discuss the relevance of daily thermal fluctuations to predict sex ratio of the Morelet's Crocodile. Copyright © 2016 Elsevier Ltd. All rights reserved.

Creating raptor benefits from powerline problems

USGS Publications Warehouse

Kochert, Michael N.; Olendorff, R.R.

1999-01-01

Powerlines benefit raptors by providing enhanced nesting and roosting sites. However, they also can kill raptors by electrocution and raptors can interfere with power transmission. The electrocution problem has been reduced by correcting existing lethal lines and implementing electrocution safe designs for new lines. Remedial actions include pole modifications, perch management and insulation of wires and hardware. New line designs provide for proper insulation and adequate spacing of conductors and grounded hardware. Nesting platforms can reduce power transmission problems and enhance the benefits of nesting on powerlines. A combination of perch deterrents and insulator shields is a positive, cost-effective approach to managing bird contamination that allows birds to continue roosting on the towers.

Eggshell Porosity Provides Insight on Evolution of Nesting in Dinosaurs.

PubMed

Tanaka, Kohei; Zelenitsky, Darla K; Therrien, François

2015-01-01

Knowledge about the types of nests built by dinosaurs can provide insight into the evolution of nesting and reproductive behaviors among archosaurs. However, the low preservation potential of their nesting materials and nesting structures means that most information can only be gleaned indirectly through comparison with extant archosaurs. Two general nest types are recognized among living archosaurs: 1) covered nests, in which eggs are incubated while fully covered by nesting material (as in crocodylians and megapodes), and 2) open nests, in which eggs are exposed in the nest and brooded (as in most birds). Previously, dinosaur nest types had been inferred by estimating the water vapor conductance (i.e., diffusive capacity) of their eggs, based on the premise that high conductance corresponds to covered nests and low conductance to open nests. However, a lack of statistical rigor and inconsistencies in this method render its application problematic and its validity questionable. As an alternative we propose a statistically rigorous approach to infer nest type based on large datasets of eggshell porosity and egg mass compiled for over 120 extant archosaur species and 29 archosaur extinct taxa/ootaxa. The presence of a strong correlation between eggshell porosity and nest type among extant archosaurs indicates that eggshell porosity can be used as a proxy for nest type, and thus discriminant analyses can help predict nest type in extinct taxa. Our results suggest that: 1) covered nests are likely the primitive condition for dinosaurs (and probably archosaurs), and 2) open nests first evolved among non-avian theropods more derived than Lourinhanosaurus and were likely widespread in non-avian maniraptorans, well before the appearance of birds. Although taphonomic evidence suggests that basal open nesters (i.e., oviraptorosaurs and troodontids) were potentially the first dinosaurs to brood their clutches, they still partially buried their eggs in sediment. Open nests with fully exposed eggs only became widespread among Euornithes. A potential co-evolution of open nests and brooding behavior among maniraptorans may have freed theropods from the ground-based restrictions inherent to covered nests and allowed the exploitation of alternate nesting locations. These changes in nesting styles and behaviors thus may have played a role in the evolutionary success of maniraptorans (including birds).

Eggshell Porosity Provides Insight on Evolution of Nesting in Dinosaurs

PubMed Central

2015-01-01

Knowledge about the types of nests built by dinosaurs can provide insight into the evolution of nesting and reproductive behaviors among archosaurs. However, the low preservation potential of their nesting materials and nesting structures means that most information can only be gleaned indirectly through comparison with extant archosaurs. Two general nest types are recognized among living archosaurs: 1) covered nests, in which eggs are incubated while fully covered by nesting material (as in crocodylians and megapodes), and 2) open nests, in which eggs are exposed in the nest and brooded (as in most birds). Previously, dinosaur nest types had been inferred by estimating the water vapor conductance (i.e., diffusive capacity) of their eggs, based on the premise that high conductance corresponds to covered nests and low conductance to open nests. However, a lack of statistical rigor and inconsistencies in this method render its application problematic and its validity questionable. As an alternative we propose a statistically rigorous approach to infer nest type based on large datasets of eggshell porosity and egg mass compiled for over 120 extant archosaur species and 29 archosaur extinct taxa/ootaxa. The presence of a strong correlation between eggshell porosity and nest type among extant archosaurs indicates that eggshell porosity can be used as a proxy for nest type, and thus discriminant analyses can help predict nest type in extinct taxa. Our results suggest that: 1) covered nests are likely the primitive condition for dinosaurs (and probably archosaurs), and 2) open nests first evolved among non-avian theropods more derived than Lourinhanosaurus and were likely widespread in non-avian maniraptorans, well before the appearance of birds. Although taphonomic evidence suggests that basal open nesters (i.e., oviraptorosaurs and troodontids) were potentially the first dinosaurs to brood their clutches, they still partially buried their eggs in sediment. Open nests with fully exposed eggs only became widespread among Euornithes. A potential co-evolution of open nests and brooding behavior among maniraptorans may have freed theropods from the ground-based restrictions inherent to covered nests and allowed the exploitation of alternate nesting locations. These changes in nesting styles and behaviors thus may have played a role in the evolutionary success of maniraptorans (including birds). PMID:26605799

Industrious leaf cutter ants and their carbon footprints

NASA Astrophysics Data System (ADS)

Swanson, A. C.; Dierick, D.; Trahan, N. A.; Allen, M. F.; Schwendenmann, L.; Harmon, T. C.; Oberbauer, S. F.; Fernandez Bou, A. S.; Zelikova, T. J.

2017-12-01

Leaf cutter ants (LCA) are considered ecosystem engineers in Neotropical forest ecosystems because they alter physical and environmental conditions for other organisms. LCA excavate large underground nests, maintaining intricate tunnels and fungal and waste chambers, and they continuously bring in vast amounts of fresh leaf material. In order to understand their ecosystem-wide impacts, we set out to determine whether their engineering activities fundamentally alter soil structure, soil nutrient pools, and gas fluxes in a wet tropical rainforest in Costa Rica. To directly compare LCA nest to non-nest sites, we utilized embedded sensor arrays with series of soil moisture, CO2, O2, and temperature sensors placed at four soil depths and automated minirhizotrons (AMR) to measure root and hyphal production and turnover. We also collected soils for biogeochemical analyses and measured soil CO2 fluxes and carbon isotope ratios of below-ground CO2 for two years. Our measurements confirmed that LCA alter their soil environment to regulate internal soil CO2 concentrations, moisture, and temperature, increasing O2 concentrations in the process. There were marked differences in soil structure inside nests relative to non-nests and these were associated with increased root and hyphal production and turnover in nests. Soil C, N, P, and their respective degrading enzymes were highly variable among sites and between nests and controls but N and P increased with soil depth and were generally higher in nests than controls. Contrary to our expectations, C mineralization rates were lower in nests but CO2 fluxes were high from nest vents and similar to non-nests elsewhere. At the system scale, LCA appear to fundamentally change the soil environment inside their nests and create spatial heterogeneity in biogeochemical processes and root and hyphal growth, influencing the overall C balance of Neotropical forests.

Nesting success of birds in different silvicultural treatments in southeastern U.S. Pine Forests

USGS Publications Warehouse

Barber, D.R.; Martin, T.E.; Melchiors, M.A.; Thill, R.E.; Wigley, T.B.

2001-01-01

We examined nesting success and levels of nest predation and cowbird parasitism among five different silvicultural treatments: regenerating (3-6 years old), mid-rotation (12-15 years old), and thinned (17-23 years old) pine plantations, single-tree selection, and late-rotation pine-hardwood stands in the Ouachita Mountains of Arkansas from 1993 to 1995. We monitored 1674 nests. Differences in daily mortality and daily predation rate among two or more treatments were found for 4 and 3 of 12 species, respectively. These differences were lost following Bonferroni adjustments, but thinned stands had higher levels of predation than single-tree selection stands when predation levels were averaged across species. Daily predation rates were positively correlated with the relative abundance of birds, suggesting that nest predators respond to prey availability (i.e., nests) in a density-dependent manner. The relative abundance of cowbirds differed among treatments, with the highest densities in regenerating, thinned, and single-tree selection stands. Field Sparrows (Spizella pusilla) and Yellow-breasted Chats (Icteria virens) experienced higher levels of parasitism in thinned than regenerating plantations, whereas White-eyed Vireos (Vireo griseus) experienced higher parasitism in regenerating plantations than in mid-rotation or thinned plantations. Several shrub-nesting and 1 ground-nesting species had lower nesting success in thinned and regenerating plantations than has been reported in previously published studies. Thus, some seral stages of even-aged management may provide low-quality nesting habitat for several early-successional bird species. In contrast, many species nesting in mid-rotation and single-tree selection stands had nesting success similar to or greater than that found in previous studies, suggesting that some silvicultural treatments, when embedded in a largely forested landscape, may provide suitable habitat for forest land birds without affecting their reproductive success.

Surplus nest boxes and the potential for polygyny affect clutch size and offspring sex ratio in house wrens

PubMed Central

Dubois, Natalie S; Dale Kennedy, E; Getty, Thomas

2006-01-01

Females of many species can gain benefits from being choosy about their mates and even exhibit context-dependent investment in reproduction in response to the quality of their breeding situation. Here, we show that if a male house wren is provided with surplus nest boxes in his territory, his mate lays a larger clutch with a significantly higher proportion of sons. This response to a territory characteristic directly associated with male competitive ability, and ultimately to male reproductive success, suggests that male competition over access to high-quality territories with surplus nest boxes (i.e. those able to support polygyny) may influence female reproductive investment decisions. The results of this study have interesting implications, particularly considering the important role that studies of cavity nesting birds utilizing nest boxes have played in advancing our understanding of behaviour, ecology and evolution. PMID:16790407

Breeding ecology of the redhead duck in western Montana

USGS Publications Warehouse

Lokemoen, J.T.

1966-01-01

The habits of the redhead duck (Aythya americana) were studied in the Flathead Valley of western Montana in 1960 and 1961 to determine their habitat preferences in this pothole breeding ground. The 2,600-acre study area, surrounding the Ninepipe Reservoir, contained 686 potholes. Redheads usually were paired by the time they arrived on the study area in March. The average density of redhead breeding pairs was 25 pairs per square mile. For all spring activities except nesting, the birds used large, deep, open potholes or breeding-pair potholes. The several breeding-pair potholes and the nesting pothole utilized by the pair comprised their home range. Starting in late April, the pairs moved about the home range as the hens selected nesting sites, usually in the dense emergent vegetation of small, shallow potholes. Hard-stem bulrush (Scirpus acutus) and cat-tail (Typha latifolia) were preferred nesting cover. Redhead nesting success was only 15 percent, a low rate apparently caused by degenerate nesting behavior complicated by high redhead density, a lack of suitable nest hosts, and certain habitat deficiencies. By late June most drakes and unsuccessful hens had moved from the potholes to nearby reservoirs. All successful hens led their newly hatched broods from the nesting potholes to larger brood potholes and many eventually moved to the reservoir. By mid-July virtually all redheads had moved from the potholes to the reservoirs, where they remained until fall migration.

Nest predation risk and growth strategies of passerine species: grow fast or develop traits to escape risk?

USGS Publications Warehouse

Cheng, Yi-Ru; Martin, Thomas E.

2012-01-01

Different body components are thought to trade off in their growth and development rates, but the causes for relative prioritization of any trait remains a critical question. Offspring of species at higher risk of predation might prioritize development of locomotor traits that facilitate escaping risky environments over growth of mass. We tested this possibility in 12 altricial passerine species that differed in their risk of nest predation. We found that rates of growth and development of mass, wings, and endothermy increased with nest predation risk across species. In particular, species with higher nest predation risk exhibited relatively faster growth of wings than of mass, fledged with relatively larger wing sizes and smaller mass, and developed endothermy earlier at relatively smaller mass. This differential development can facilitate both escape from predators and survival outside of the nest environment. Tarsus growth was not differentially prioritized with respect to nest predation risk, and instead all species achieved adult tarsus size by age of fledging. We also tested whether different foraging modes (aerial, arboreal, and ground foragers) might explain the variation of differential growth of locomotor modules, but we found that little residual variation was explained. Our results suggest that differences in nest predation risk among species are associated with relative prioritization of body components to facilitate escape from the risky nest environment.

Invasive rats strengthen predation pressure on bird eggs in a South Pacific island rainforest

PubMed Central

Bourguet, Edouard; De Meringo, Hélène; Millon, Alexandre; Vidal, Eric

2017-01-01

Abstract Invasive rats (Rattus spp.) are known to have pervasive impacts on island birds, particularly on their nesting success. To conserve or restore bird populations, numerous invasive rat control or eradication projects are undertaken on islands worldwide. However, such projects represent a huge investment and the decision-making process requires proper assessment of rat impacts. Here, we assessed the influence of two sympatric invasive rats (Rattus rattus and R. exulans) on native bird eggs in a New Caledonian rainforest, using artificial bird-nest monitoring. A total of 178 artificial nests containing two eggs of three different sizes were placed either on the ground or 1.5 m high and monitored at the start of the birds’ breeding season. Overall, 12.4% of the nests were depredated during the first 7 days. At site 1, where nests were monitored during 16 days, 41.8% of the nests were depredated. The main predator was the native crow Corvus moneduloides, responsible for 62.9% of the overall predation events. Rats were responsible for only 22.9% of the events, and ate only small and medium eggs at both heights. Our experiment suggests that in New Caledonia, predation pressure by rats strengthens overall bird-nest predation, adding to that by native predators. Experimental rat control operations may allow reduced predation pressure on nests as well as the recording of biodiversity responses after rat population reduction. PMID:29492018

Invasive rats strengthen predation pressure on bird eggs in a South Pacific island rainforest.

PubMed

Duron, Quiterie; Bourguet, Edouard; De Meringo, Hélène; Millon, Alexandre; Vidal, Eric

2017-12-01

Invasive rats ( Rattus spp.) are known to have pervasive impacts on island birds, particularly on their nesting success. To conserve or restore bird populations, numerous invasive rat control or eradication projects are undertaken on islands worldwide. However, such projects represent a huge investment and the decision-making process requires proper assessment of rat impacts. Here, we assessed the influence of two sympatric invasive rats ( Rattus rattus and R. exulans ) on native bird eggs in a New Caledonian rainforest, using artificial bird-nest monitoring. A total of 178 artificial nests containing two eggs of three different sizes were placed either on the ground or 1.5 m high and monitored at the start of the birds' breeding season. Overall, 12.4% of the nests were depredated during the first 7 days. At site 1, where nests were monitored during 16 days, 41.8% of the nests were depredated. The main predator was the native crow Corvus moneduloides , responsible for 62.9% of the overall predation events. Rats were responsible for only 22.9% of the events, and ate only small and medium eggs at both heights. Our experiment suggests that in New Caledonia, predation pressure by rats strengthens overall bird-nest predation, adding to that by native predators. Experimental rat control operations may allow reduced predation pressure on nests as well as the recording of biodiversity responses after rat population reduction.

Breeding habitat use by sympatric and allopatric populations of Wilson's Warblers and Yellow Warblers

USGS Publications Warehouse

Ruth, J.M.; Stanley, T.R.

2002-01-01

We studied Wilson's Warbler (Wilsonia pusilla) and Yellow Warbler (Dendroica petechia) habitat use in allopatric and sympatric populations in the Rocky Mountains of northern Colorado and southeastern Wyoming in order to better understand the different habitat needs and interactions of these two species. Foraging Wilson's Warblers and Yellow Warblers used very similar habitat, both selecting larger, more open shrubs. In spite of similar foraging habitat, comparisons of habitat use by the two species at the sympatric sites yielded no evidence of foraging habitat partitioning or exclusion. There was evidence of nesting habitat partitioning. Wilson's Warblers nested on the ground, with some evidence that they used smaller, more densely stemmed shrubs under which to nest. Yellow Warblers are shrub nesters and selected larger, more open shrubs in which to nest. Results provide no evidence that Yellow Warblers can be blamed for population declines in Wilson's Warblers.

KSC-06pd0474

NASA Image and Video Library

2006-03-11

KENNEDY SPACE CENTER, FLA. - A bald eagle on the ground may be protecting its food or resting after a hunt for food. This one was spotted near S.R. 3 on Kennedy Space Center, close to its nest. The nest is one of a dozen active nests throughout the Merritt Island National Wildlife Refuge, which shares a boundary with the Center. Eagles' habitats are near lakes, rivers, marshes and seacoasts. Nests are masses of sticks, usually in the top of a tall tree. Even though they are fish eaters, bald eagles will take whatever prey is available and easiest to obtain. Bald eagles which live along the coast and on major lakes and rivers feed mainly on fish. Bald eagles fish in both fresh and salt water. Because of the energy expended during hunting, an eagle has to spend a lot of time resting quietly. It's estimated that only one out of eighteen attacks are successful. Photo credit: NASA/Jim Grossmann

Daily Activity and Nest Occupation Patterns of Fox Squirrels (Sciurus niger) throughout the Year.

PubMed

Wassmer, Thomas; Refinetti, Roberto

2016-01-01

The authors investigated the general activity and nest occupation patterns of fox squirrels in a natural setting using temperature-sensitive data loggers that measure activity as changes in the microenvironment of the animal. Data were obtained from 25 distinct preparations, upon 14 unique squirrels, totaling 1385 recording days. The animals were clearly diurnal, with a predominantly unimodal activity pattern, although individual squirrels occasionally exhibited bimodal patterns, particularly in the spring and summer. Even during the short days of winter (9 hours of light), the squirrels typically left the nest after dawn and returned before dusk, spending only about 7 hours out of the nest each day. Although the duration of the daily active phase did not change with the seasons, the squirrels exited the nest earlier in the day when the days became longer in the summer and exited the nest later in the day when the days became shorter in the winter, thus tracking dawn along the seasons. During the few hours spent outside the nest each day, fox squirrels seemed to spend most of the time sitting or lying. These findings suggest that fox squirrels may have adopted a slow life history strategy that involves long periods of rest on trees and short periods of ground activity each day.

KSC-03pd0775

NASA Image and Video Library

2003-03-19

KENNEDY SPACE CENTER, FLA. - Framed by the NASA insignia, on the outside of the Vehicle Assembly Building, this osprey stares out from the nest it has built on top of speakers in a nearby parking lot. Known as a fish hawk, the osprey selects sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-03pd0776

NASA Image and Video Library

2003-03-19

KENNEDY SPACE CENTER, Fla. - Framed by the NASA insignia, on the outside of the Vehicle Assembly Building, this osprey stares out from the nest it has built on top of speakers in a nearby parking lot. Known as a fish hawk, the osprey selects sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States it is found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

KSC-04pd0952

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - An osprey likes the view atop this American flag, which flies near the NASA KSC News Center. It’s nest is located atop a speaker in the parking lot. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge.

Resource overlap and possible competition between honey bees and wild bees in central Europe.

PubMed

Steffan-Dewenter, I; Tscharntke, T

2000-02-01

Evidence for interspecific competition between honey bees and wild bees was studied on 15 calcareous grasslands with respect to: (1) foraging radius of honey bees, (2) overlap in resource use, and (3) possible honey bee effects on species richness and abundance of flower-visiting, ground-nesting and trap-nesting wild bees. The grasslands greatly differed in the number of honey bee colonies within a radius of 2 km and were surrounded by agricultural habitats. The number of flower-visiting honey bees on both potted mustard plants and small grassland patches declined with increasing distance from the nearest apiary and was almost zero at a distance of 1.5-2.0 km. Wild bees were observed visiting 57 plant species, whereas honey bees visited only 24 plant species. Percentage resource overlap between honey bees and wild bees was 45.5%, and Hurlbert's index of niche overlap was 3.1. In total, 1849 wild bees from 98 species were recorded on the calcareous grasslands. Neither species richness nor abundance of wild bees were negatively correlated with the density of honey bee colonies (within a radius of 2 km) or the density of flower-visiting honey bees per site. Abundance of flower- visiting wild bees was correlated only with the percentage cover of flowering plants. In 240 trap nests, 1292 bee nests with 6066 brood cells were found. Neither the number of bee species nor the number of brood cells per grassland was significantly correlated with the density of honey bees. Significant correlations were found only between the number of brood cells and the percentage cover of shrubs. The number of nest entrances of ground-nesting bees per square metre was not correlated with the density of honey bees but was negatively correlated with the cover of vegetation. Interspecific competition by honey bees for food resources was not shown to be a significant factor determining abundance and species richness of wild bees.

Ghrelin and leptin modulate the feeding behaviour of the hawksbill turtle Eretmochelys imbricata during nesting season

PubMed Central

Goldberg, Daphne Wrobel; Leitão, Santiago Alonso Tobar; Godfrey, Matthew H.; Lopez, Gustave Gilles; Santos, Armando José Barsante; Neves, Fabiana Alves; de Souza, Érica Patrícia Garcia; Moura, Anibal Sanchez; Bastos, Jayme da Cunha; Bastos, Vera Lúcia Freire da Cunha

2013-01-01

Female sea turtles have rarely been observed foraging during the nesting season. This suggests that prior to their migration to nesting beaches the females must store sufficient energy and nutrients at their foraging grounds and must be physiologically capable of undergoing months without feeding. Leptin (an appetite-suppressing protein) and ghrelin (a hunger-stimulating peptide) affect body weight by influencing energy intake in all vertebrates. We investigated the levels of these hormones and other physiological and nutritional parameters in nesting hawksbill sea turtles in Rio Grande do Norte State, Brazil, by collecting consecutive blood samples from 41 turtles during the 2010–2011 and 2011–2012 reproductive seasons. We found that levels of serum leptin decreased over the nesting season, which potentially relaxed suppression of food intake and stimulated females to begin foraging either during or after the post-nesting migration. Concurrently, we recorded an increasing trend in ghrelin, which may have stimulated food intake towards the end of the nesting season. Both findings are consistent with the prediction that post-nesting females will begin to forage, either during or immediately after their post-nesting migration. We observed no seasonal trend for other physiological parameters (values of packed cell volume and serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, low-density lipoprotein, and high-density lipoprotein). The observed downward trends in general serum biochemistry levels were probably due to the physiological challenge of vitellogenesis and nesting in addition to limited energy resources and probable fasting. PMID:27293600

Firewalls in bee nests-survival value of propolis walls of wild Cape honeybee (Apis mellifera capensis).

PubMed

Tribe, Geoff; Tautz, Jürgen; Sternberg, Karin; Cullinan, Jenny

2017-04-01

The Cape bee is endemic to the winter rainfall region of South Africa where fires are an integral part of the ecology of the fynbos (heathland) vegetation. Of the 37 wild nests in pristine Peninsula Sandstone Fynbos in the Cape Point section of Table Mountain National Park that have been analyzed so far, only 22 could be accessed sufficiently to determine the existence of a propolis wall of which 68% had propolis walls which entirely enclosed their openings. The analysis of the 37 wild nests revealed that 78% occurred under boulders or in clefts within rocks, 11% in the ground, 8% in tree cavities, and 3% within shrubs. The analysis of 17 of these nests following a fire within the park revealed that the propolis walls materially protected the nests and retarded the fire with all the colonies surviving. The bees responded to the smoke by imbibing honey and retreating to the furthest recess of their nest cavity. The bees were required to utilize this honey for about 3 weeks after which fire-loving plants appeared and began flowering. Considerable resources were utilized in the construction of the propolis walls, which ranged in thickness from 1.5 to 40 mm (mean 5 mm). Its physical environment determines the nesting behavior of the Cape bee. The prolific use of propolis serves to insulate the nest from extremes of temperature and humidity, restricts entry, camouflages the nest, and acts as an effective fire barrier protecting nests established mostly under rocks in vegetation subjected to periodic fires.

What constitutes a nesting attempt? Variation in criteria causes bias and hinders comparisons across studies

USGS Publications Warehouse

Garcia, V.; Conway, C.J.

2009-01-01

Because reliable estimates of nesting success are very important to avian studies, the defnition of a “successful nest” and the use of different analytical methods to estimate success have received much attention. By contrast, variation in the criteria used to determine whether an occupied site that did not produce offspring contained a nesting attempt is a source of bias that has been largely ignored. This problem is especially severe in studies that deal with species whose nest contents are relatively inaccessible because observers cannot determine whether or not an egg was laid for a large proportion of occupied sites. Burrowing Owls (Athene cunicularia) often lay their eggs ≥3 m below ground, so past Burrowing Owl studies have used a variety of criteria to determine whether a nesting attempt was initiated. We searched the literature to document the extent of that variation and examined how that variation influenced estimates of daily nest survival. We found 13 different sets of criteria used by previous authors and applied each criterion to our data set of 1,300 occupied burrows. We found significant variation in estimates of daily nest survival depending on the criteria used. Moreover, differences in daily nest survival among populations were apparent using some sets of criteria but not others. These inconsistencies may lead to incorrect conclusions and invalidate comparisons of the productivity and relative site quality among populations. We encourage future authors working on cavity-, canopy-, or burrow-nesting birds to provide specific details on the criteria they used to identify a nesting attempt.

Ghrelin and leptin modulate the feeding behaviour of the hawksbill turtle Eretmochelys imbricata during nesting season.

PubMed

Goldberg, Daphne Wrobel; Leitão, Santiago Alonso Tobar; Godfrey, Matthew H; Lopez, Gustave Gilles; Santos, Armando José Barsante; Neves, Fabiana Alves; de Souza, Érica Patrícia Garcia; Moura, Anibal Sanchez; Bastos, Jayme da Cunha; Bastos, Vera Lúcia Freire da Cunha

2013-01-01

Female sea turtles have rarely been observed foraging during the nesting season. This suggests that prior to their migration to nesting beaches the females must store sufficient energy and nutrients at their foraging grounds and must be physiologically capable of undergoing months without feeding. Leptin (an appetite-suppressing protein) and ghrelin (a hunger-stimulating peptide) affect body weight by influencing energy intake in all vertebrates. We investigated the levels of these hormones and other physiological and nutritional parameters in nesting hawksbill sea turtles in Rio Grande do Norte State, Brazil, by collecting consecutive blood samples from 41 turtles during the 2010-2011 and 2011-2012 reproductive seasons. We found that levels of serum leptin decreased over the nesting season, which potentially relaxed suppression of food intake and stimulated females to begin foraging either during or after the post-nesting migration. Concurrently, we recorded an increasing trend in ghrelin, which may have stimulated food intake towards the end of the nesting season. Both findings are consistent with the prediction that post-nesting females will begin to forage, either during or immediately after their post-nesting migration. We observed no seasonal trend for other physiological parameters (values of packed cell volume and serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, low-density lipoprotein, and high-density lipoprotein). The observed downward trends in general serum biochemistry levels were probably due to the physiological challenge of vitellogenesis and nesting in addition to limited energy resources and probable fasting.

Beach erosion and nest site selection by the leatherback sea turtle Dermochelys coriacea (Testudines: Dermochelyidae) and implications for management practices at Playa Gandoca, Costa Rica.

PubMed

Spanier, Matthew J

2010-12-01

Leatherback sea turtles (Dermochelys coriacea) nest on dynamic, erosion-prone beaches. Erosive processes and resulting nest loss have long been presumed to be a hindrance to clutch survival. In order to better understand how leatherbacks cope with unstable nesting beaches, I investigated the role of beach erosion in leatherback nest site selection at Playa Gandoca, Costa Rica. I also examined the potential effect of nest relocation, a conservation strategy in place at Playa Gandoca to prevent nest loss to erosion, on the temperature of incubating clutches. I monitored changes in beach structure as a result of erosion at natural nest sites during the time the nest was laid, as well as in subsequent weeks. To investigate slope as a cue for nest site selection, I measured the slope of the beach where turtles ascended from the sea to nest, as well as the slopes at other random locations on the beach for comparison. I examined temperature differences between natural and relocated nest sites with thermocouples placed in the sand at depths typical of leatherback nests. Nests were distributed non-randomly in a clumped distribution along the length of the beach and laid at locations that were not undergoing erosion. The slope at nest sites was significantly different than at randomly chosen locations on the beach. The sand temperature at nest depths was significantly warmer at natural nest sites than at locations of relocated nests. The findings of this study suggest leatherbacks actively select nest sites that are not undergoing erosive processes, with slope potentially being used as a cue for site selection. The relocation of nests appears to be inadvertently cooling the nest environment. Due to the fact that leatherback clutches undergo temperature-dependent sex determination, the relocation of nests may be producing an unnatural male biasing of hatchlings. The results of this study suggest that the necessity of relocation practices, largely in place to protect nests from erosion, should be reevaluated to ensure the proper conservation of this critically endangered species.

Wintering area DDE source to migratory white-faced ibis revealed by satellite telemetry and prey sampling.

PubMed

Yates, Michael A; Fuller, Mark R; Henny, Charles J; Seegar, William S; Garcia, Jaqueline

2010-01-01

Locations of contaminant exposure for nesting migratory species are difficult to fully understand because of possible additional sources encountered during migration or on the wintering grounds. A portion of the migratory white-faced ibis (Plegadis chihi) nesting at Carson Lake, Nevada continues to be exposed to dichloro-diphenyldichloro-ethylene (DDE) with no change, which is unusual, observed in egg concentrations between 1985 and 2000. About 45-63% of the earliest nesting segment shows reduced reproductive success correlated with elevated egg concentrations of >4 microg/g wet weight (ww). Local prey (primarily earthworms) near nests contained little DDE so we tracked the migration and wintering movements of 20 adult males during 2000-2004 to determine the possible source. At various wintering sites, we found a correlation (r (2) = 0.518, P = 0.0125, N = 11) between DDE in earthworm composites and DDE in blood plasma of white-faced ibis wintering there, although the plasma was collected on their breeding grounds soon after arrival. The main source of DDE was wintering areas in the Mexicali Valley of Baja California Norte, Mexico, and probably the adjacent Imperial Valley, California, USA. This unusual continuing DDE problem for white-faced ibis is associated with: the long-term persistence in soil of DDE; the earthworms' ability to bioconcentrate DDE from soil; the proclivity of white-faced ibis to feed on earthworms in agricultural fields; the species's extreme sensitivity to DDE in their eggs; and perhaps its life history strategy of being a "capital breeder". We suggest surveying and sampling white-faced ibis eggs at nesting colonies, especially at Carson Lake, to monitor the continuing influence of DDE.

Wintering area DDE source to migratory white-faced ibis revealed by satellite telemetry and prey sampling

USGS Publications Warehouse

Yates, M.A.; Fuller, M.R.; Henny, C.J.; Seegar, W.S.; Garcia, Jorge H.

2010-01-01

Locations of contaminant exposure for nesting migratory species are difficult to fully understand because of possible additional sources encountered during migration or on the wintering grounds. A portion of the migratory white-faced ibis (Plegadis chihi) nesting at Carson Lake, Nevada continues to be exposed to dichloro-diphenyldichloro-ethylene (DDE) with no change, which is unusual, observed in egg concentrations between 1985 and 2000. About 45-63% of the earliest nesting segment shows reduced reproductive success correlated with elevated egg concentrations of >4 ??g/g wet weight (ww). Local prey (primarily earthworms) near nests contained little DDE so we tracked the migration and wintering movements of 20 adult males during 2000-2004 to determine the possible source. At various wintering sites, we found a correlation (r 2 = 0.518, P = 0.0125, N = 11) between DDE in earthworm composites and DDE in blood plasma of white-faced ibis wintering there, although the plasma was collected on their breeding grounds soon after arrival. The main source of DDE was wintering areas in the Mexicali Valley of Baja California Norte, Mexico, and probably the adjacent Imperial Valley, California, USA. This unusual continuing DDE problem for white-faced ibis is associated with: the long-term persistence in soil of DDE; the earthworms' ability to bioconcentrate DDE from soil; the proclivity of white-faced ibis to feed on earthworms in agricultural fields; the species's extreme sensitivity to DDE in their eggs; and perhaps its life history strategy of being a "capital breeder". We suggest surveying and sampling white-faced ibis eggs at nesting colonies, especially at Carson Lake, to monitor the continuing influence of DDE. ?? 2009 Springer Science+Business Media, LLC.

Effects of shallow natural gas well structures and associated roads on grassland songbird reproductive success in Alberta, Canada

PubMed Central

Koper, Nicola

2017-01-01

Grassland songbird populations across North America have experienced dramatic population declines due to habitat loss and degradation. In Canada, energy development continues to fragment and disturb prairie habitat, but effects of oil and gas development on reproductive success of songbirds in North American mixed-grass prairies remains largely unknown. From 2010–2012, in southeastern Alberta, Canada, we monitored 257 nests of two ground-nesting grassland songbird species, Savannah sparrow (Passerculus sandwichensis) and chestnut-collared longspur (Calcarius ornatus). Nest locations varied with proximity to and density of conventional shallow gas well structures and associated roads in forty-two 258-ha mixed-grass prairie sites. We estimated the probabilities of nest success and clutch size relative to gas well structures and roads. There was little effect of distance to or density of gas well structure on nest success; however, Savannah sparrow experienced lower nest success near roads. Clutch sizes were lower near gas well structures and cattle water sources. Minimizing habitat disturbance surrounding gas well structures, and reducing abundance of roads and trails, would help minimize impacts on reproductive success for some grassland songbirds. PMID:28355241

Effects of shallow natural gas well structures and associated roads on grassland songbird reproductive success in Alberta, Canada.

PubMed

Yoo, Jenny; Koper, Nicola

2017-01-01

Grassland songbird populations across North America have experienced dramatic population declines due to habitat loss and degradation. In Canada, energy development continues to fragment and disturb prairie habitat, but effects of oil and gas development on reproductive success of songbirds in North American mixed-grass prairies remains largely unknown. From 2010-2012, in southeastern Alberta, Canada, we monitored 257 nests of two ground-nesting grassland songbird species, Savannah sparrow (Passerculus sandwichensis) and chestnut-collared longspur (Calcarius ornatus). Nest locations varied with proximity to and density of conventional shallow gas well structures and associated roads in forty-two 258-ha mixed-grass prairie sites. We estimated the probabilities of nest success and clutch size relative to gas well structures and roads. There was little effect of distance to or density of gas well structure on nest success; however, Savannah sparrow experienced lower nest success near roads. Clutch sizes were lower near gas well structures and cattle water sources. Minimizing habitat disturbance surrounding gas well structures, and reducing abundance of roads and trails, would help minimize impacts on reproductive success for some grassland songbirds.

Variability in individual assessment behaviour and its implications for collective decision-making.

PubMed

O'Shea-Wheller, Thomas A; Masuda, Naoki; Sendova-Franks, Ana B; Franks, Nigel R

2017-02-08

Self-organized systems of collective behaviour have been demonstrated in a number of group-living organisms. There is, however, less research relating to how variation in individual assessments may facilitate group decision-making. Here, we investigate this using the decentralized system of collective nest choice behaviour employed by the ant Temnothorax albipennis, combining experimental results with computational modelling. In experiments, isolated workers of this species were allowed to investigate new nest sites of differing quality, and it was found that for any given nest quality, there was wide variation among individuals in the durations that they spent within each nest site. Additionally, individual workers were consistent in spending more time in nest sites of higher quality, and less time in those of lower quality. Hence, the time spent in a new nest site must have included an assessment of nest quality. As nest site visit durations (henceforth termed assessment durations) are linked to recruitment, it is possible that the variability we observed may influence the collective decision-making process of colonies. Thus, we explored this further using a computational model of nest site selection, and found that heterogeneous nest assessments conferred a number of potential benefits. Furthermore, our experiments showed that nest quality assessments were flexible, being influenced by experience of prior options. Our findings help to elucidate the potential mechanisms underlying group behaviour, and highlight the importance of heterogeneity among individuals, rather than precise calibration, in shaping collective decision-making. © 2017 The Author(s).

Weather radar data correlate to hail-induced mortality in grassland birds

USGS Publications Warehouse

Carver, Amber; Ross, Jeremy D.; Augustine, David J.; Skagen, Susan K.; Dwyer, Angela M.; Tomback, Diana F.; Wunder, Michael B.

2017-01-01

Small-bodied terrestrial animals such as songbirds (Order Passeriformes) are especially vulnerable to hail-induced mortality; yet, hail events are challenging to predict, and they often occur in locations where populations are not being studied. Focusing on nesting grassland songbirds, we demonstrate a novel approach to estimate hail-induced mortality. We quantify the relationship between the probability of nests destroyed by hail and measured Level-III Next Generation Radar (NEXRAD) data, including atmospheric base reflectivity, maximum estimated size of hail and maximum estimated azimuthal wind shear. On 22 June 2014, a hailstorm in northern Colorado destroyed 102 out of 203 known nests within our research site. Lark bunting (Calamospiza melanocorys) nests comprised most of the sample (n = 186). Destroyed nests were more likely to be found in areas of higher storm intensity, and distributions of NEXRAD variables differed between failed and surviving nests. For 133 ground nests where nest-site vegetation was measured, we examined the ameliorative influence of woody vegetation, nest cover and vegetation density by comparing results for 13 different logistic regression models incorporating the independent and additive effects of weather and vegetation variables. The most parsimonious model used only the interactive effect of hail size and wind shear to predict the probability of nest survival, and the data provided no support for any of the models without this predictor. We conclude that vegetation structure may not mitigate mortality from severe hailstorms and that weather radar products can be used remotely to estimate potential for hail mortality of nesting grassland birds. These insights will improve the efficacy of grassland bird population models under predicted climate change scenarios.

Major benefits of guarding behavior in subsocial bees: implications for social evolution.

PubMed

Mikát, Michael; Černá, Kateřina; Straka, Jakub

2016-10-01

Parental care is a behavior that increases the growth and survival of offspring, often at a cost to the parents' own survival and/or future reproduction. In this study, we focused on nest guarding, which is one of the most important types of extended parental care; we studied this behavior in two solitary bee species of the genus Ceratina with social ancestors. We performed the experiment of removing the laying female, who usually guards the nest after completing its provisioning, to test the effects of nest guarding on the offspring survival and nest fate. By dissecting natural nests, we found that Ceratina cucurbitina females always guarded their offspring until the offspring reached adulthood. In addition, the females of this species were able to crawl across the nest partitions and inspect the offspring in the brood cells. In contrast, several Ceratina chalybea females guarded their nests until the offspring reached adulthood, but others closed the nest entrance with a plug and deserted the nest. Nests with a low number of provisioned cells were more likely to be plugged and abandoned than nests with a higher number of cells. The female removal experiment had a significantly negative effect on offspring survival in both species. These nests frequently failed due to the attacks of natural enemies (e.g., ants, chalcidoid wasps, and other competing Ceratina bees). Increased offspring survival is the most important benefit of the guarding strategy. The abandonment of a potentially unsuccessful brood might constitute a benefit of the nest plugging behavior. The facultative nest desertion strategy is a derived behavior in the studied bees and constitutes an example of an evolutionary reduction in the extent of parental care.

Non-invasive genetics outperforms morphological methods in faecal dietary analysis, revealing wild boar as a considerable conservation concern for ground-nesting birds.

PubMed

Oja, Ragne; Soe, Egle; Valdmann, Harri; Saarma, Urmas

2017-01-01

Capercaillie (Tetrao urogallus) and other grouse species represent conservation concerns across Europe due to their negative abundance trends. In addition to habitat deterioration, predation is considered a major factor contributing to population declines. While the role of generalist predators on grouse predation is relatively well known, the impact of the omnivorous wild boar has remained elusive. We hypothesize that wild boar is an important predator of ground-nesting birds, but has been neglected as a bird predator because traditional morphological methods underestimate the proportion of birds in wild boar diet. To distinguish between different mammalian predator species, as well as different grouse prey species, we developed a molecular method based on the analysis of mitochondrial DNA that allows accurate species identification. We collected 109 wild boar faeces at protected capercaillie leks and surrounding areas and analysed bird consumption using genetic methods and classical morphological examination. Genetic analysis revealed that the proportion of birds in wild boar faeces was significantly higher (17.3%; 4.5×) than indicated by morphological examination (3.8%). Moreover, the genetic method allowed considerably more precise taxonomic identification of consumed birds compared to morphological analysis. Our results demonstrate: (i) the value of using genetic approaches in faecal dietary analysis due to their higher sensitivity, and (ii) that wild boar is an important predator of ground-nesting birds, deserving serious consideration in conservation planning for capercaillie and other grouse.

Experimental demonstration of a parasite-induced immune response in wild birds: Darwin's finches and introduced nest flies.

PubMed

Koop, Jennifer A H; Owen, Jeb P; Knutie, Sarah A; Aguilar, Maria A; Clayton, Dale H

2013-08-01

Ecological immunology aims to explain variation among hosts in the strength and efficacy of immunological defenses. However, a shortcoming has been the failure to link host immune responses to actual parasites under natural conditions. Here, we present one of the first experimental demonstrations of a parasite-induced immune response in a wild bird population. The recently introduced ectoparasitic nest fly Philornis downsi severely impacts the fitness of Darwin's finches and other land birds in the Galápagos Islands. An earlier study showed that female medium ground finches (Geospiza fortis) had P. downsi-binding antibodies correlating with presumed variation in fly exposure over time. In the current study, we experimentally manipulated fly abundance to test whether the fly does, in fact, cause changes in antibody levels. We manipulated P. downsi abundance in nests and quantified P. downsi-binding antibody levels of medium ground finch mothers, fathers, and nestlings. We also quantified host behaviors, such as preening, which can integrate with antibody-mediated defenses against ectoparasites. Philornis downsi-binding antibody levels were significantly higher among mothers at parasitized nests, compared to mothers at (fumigated) nonparasitized nests. Mothers with higher antibody levels tended to have fewer parasites in their nests, suggesting that antibodies play a role in defense against parasites. Mothers showed no behavioral changes that would enhance the effectiveness of the immune response. Neither adult males, nor nestlings, had P. downsi-induced immunological or behavioral responses that would enhance defense against flies. None of the parasitized nests fledged any offspring, despite the immune response by mothers. Thus, this study shows that, while the immune response of mothers appeared to be defensive, it was not sufficient to rescue current reproductive fitness. This study further shows the importance of testing the fitness consequences of immune defenses, rather than assuming that such responses increase host fitness. Host immune responses can protect against the negative fitness consequences of parasitism; however, the strength and effectiveness of these responses vary among hosts. Strong host immune responses are often assumed to correlate with greater host fitness. This study investigates the relationship between host immune response, parasite load, and host fitness using Darwin's finches and an invasive nest parasite. We found that while the immune response of mothers appeared defensive, it did not rescue current reproductive fitness.

Nest-site competition between invasive and native cavity nesting birds and its implication for conservation.

PubMed

Charter, Motti; Izhaki, Ido; Ben Mocha, Yitzchak; Kark, Salit

2016-10-01

Nesting cavities are often a limited resource that multiple species use. There is an ongoing discussion on whether invasive cavity nesting birds restrict the availability of this key limited resource. While the answer to this question has important conservation implications, little experimental work has been done to examine it. Here, we aimed to experimentally test whether alien cavity nesting birds affect the occupancy of cavities and the resulting breeding success of native cavity breeders in a large urban park located in Tel Aviv, Israel. Over three breeding seasons, we manipulated the entry size of nest boxes and compared the occupancy and breeding success of birds in nest boxes of two treatments. These included nest boxes with large-entrance and small-entrance holes. The large-entrance holes allowed access for both the native and invasive birds (the two main aliens in the park are the common mynas and rose-ringed parakeets). The smaller-entrance boxes, on the other hand, allowed only the smaller sized native cavity breeders (great tits and house sparrows) to enter the boxes but prevented the alien species from entering. We found that the large-entrance nest boxes were occupied by five different bird species, comprising three natives (great tit, house sparrow, Scops owl) and two invasive species (common myna, rose-ringed parakeet) while the small-entrance boxes were only occupied by the two native species. The alien common mynas and rose-ringed parakeets occupied 77.5% of the large-entrance nest boxes whereas native species, mainly great tits, occupied less than 9% of the large-entrance boxes and 36.5% of the small-entrance boxes. When examining the occupancy of those cavities that were not occupied by the aliens, natives occupied both the small and large-entrance nest boxes equally. Three quarters (78%) of the great tits breeding in the large-entrance boxes were usurped by common mynas during the breeding season and as a result breeding success was significantly lower for great tits breeding in the large-entrance boxes compared with the small-entrance boxes. The results of this study suggests that the invasive alien species can reduce the breeding potential of native cavity breeders both by exploiting the limited breeding resource (nest cavities) and by directly usurping cavities already occupied by the native species. Since the majority of large-entrance nest boxes were occupied by the larger alien birds, less native species bred in the limited number of unoccupied large-entrance nest boxes because of exploitation competition. We propose that for management purposes, nest-box programs that alter the entrance size of available natural cavities may be a practical approach, reducing the competition between native cavity breeders and alien invasive birds, and especially benefiting the smaller native cavity breeders. Copyright © 2016 Elsevier Ltd. All rights reserved.

KSC-06pd0846

NASA Image and Video Library

2006-05-17

KENNEDY SPACE CENTER, FLA. -- A baby osprey sits on its nest situated at the top of a pole in the parking lot at the NASA News Center at Kennedy Space Center. Behind the nest can be seen the immense flag painted on the side of the Vehicle Assembly Building. This is the third year the ospreys have raised a family at the News Center. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge, which shares a boundary with the Center. Photo credit: NASA/George Shelton

KSC-2009-1511

NASA Image and Video Library

2009-01-31

CAPE CANAVERAL, Fla. – An osprey flies high near the NASA News Center at NASA's Kennedy Space Center in Florida returning to its nest nearby. The osprey, also called fish hawk, is well adapted for capturing fish, which make up its entire diet. The soles of the birds' feet are equipped with sharp, spiny projections that give the bird a firm grip on its slippery prey. Nests of ospreys are bulky masses of sticks and debris placed in a tree, on rocks, flat ground or telephone poles. Many nests exist around the Launch Complex 39 Area at the center. The bird is one of more than 500 species of birds that co-exist at the center and the surrounding Merritt Island National Wildlife Refuge. Photo credit: NASA/Ben Smelgelsky

The Distribution of Nesting White-bellied Sea-eagle (Haliaeetus leucogaster) in Penang National Park, Malaysia: Conservation and Management Issues

PubMed Central

Azman, Nur Munira; Zainudin, Mohd Syafiq Masduqi Mohd; Sah, Shahrul Anuar Mohd; Latip, Nurul Salmi Abdul

2013-01-01

Taman Negara Pulau Pinang (Penang National Park) is the only site on Pulau Pinang that supports a large population of the White-bellied Sea-eagle (WBSE) Haliaeetus leucogaster; however, the nesting sites of WBSEs have not been widely studied. As information on the location of WBSE nesting sites is very important for conservation works by local authorities, the objective of this study was to determine the distribution of nesting WBSEs in the coastal dipterocarp forest of Penang National Park. Surveys were conducted from December 2007 to July 2008 and October 2008 to April 2009, covering the breeding season of the species (September–July). The nesting sites were observed by boat along the coastline of Penang National Park and by performing ground surveys along the seashore at accessible areas; the nest survey was conducted three days/month from 0900 to 1500. A total of 34 WBSE nesting sites was located. Most of the occupied nests (seven nests) were found at Muka Head and Pantai Kerachut areas, which exhibit the densest concentration of occupied WBSE habitat in Penang National Park. WBSEs preferred to build their nests around Muka Head, which could be due to the frequent occurrence of whirlpools in the water body around that area. Aquatic animals, such as sea snakes and fish, stunned by the whirlpools would emerge to the sea surface, facilitating the foraging and feeding of WBSEs. Our results indicate that it is important to maintain and improve areas of suitable nesting habitat for WBSEs. Management actions should include (1) the yearly monitoring of known breeding sites throughout Penang National Park during the breeding season to determine breeding success over time, (2) recognising the critical habitat or nest-site selection of WBSEs, (3) establishment of a buffer zone surrounding nesting sites and potential habitat from human disturbance, and (4) encouraging on-going research to further understand this species. PMID:24575248

Nest site selection by Kentish plover suggests a trade-off between nest-crypsis and predator detection strategies.

PubMed

Gómez-Serrano, Miguel Ángel; López-López, Pascual

2014-01-01

Predation is one of the main causes of adult mortality and breeding failure for ground-nesting birds. Micro-habitat structure around nests plays a critical role in minimizing predation risk. Plovers nest in sites with little vegetation cover to maximize the incubating adult visibility, but many studies suggest a trade-off between nest-crypsis and predator detection strategies. However, this trade-off has not been explored in detail because methods used so far do not allow estimating the visibility with regards to critical factors such as slope or plant permeability to vision. Here, we tested the hypothesis that Kentish plovers select exposed sites according to a predator detection strategy, and the hypothesis that more concealed nests survive longer according to a crypsis strategy. To this end, we obtained an accurate estimation of the incubating adult's field of vision through a custom built inverted periscope. Our results showed that plovers selected nest sites with higher visibility than control points randomly selected with regards to humans and dogs, although nests located in sites with higher vegetation cover survived longer. In addition, the flushing distance (i.e., the distance at which incubating adults leave the nest when they detect a potential predator) decreased with vegetation cover. Consequently, the advantages of concealing the nest were limited by the ability to detect predators, thus indirectly supporting the existence of the trade-off between crypsis and predator detection. Finally, human disturbance also constrained nest choice, forcing plovers to move to inland sites that were less suitable because of higher vegetation cover, and modulated flushing behavior, since plovers that were habituated to humans left their nests closer to potential predators. This constraint on the width of suitable breeding habitat is particularly relevant for the conservation of Kentish Plover in sand beaches, especially under the current context of coastal regression and increase of recreational activities.

Nest Site Selection by Kentish Plover Suggests a Trade-Off between Nest-Crypsis and Predator Detection Strategies

PubMed Central

Gómez-Serrano, Miguel Ángel; López-López, Pascual

2014-01-01

Predation is one of the main causes of adult mortality and breeding failure for ground-nesting birds. Micro-habitat structure around nests plays a critical role in minimizing predation risk. Plovers nest in sites with little vegetation cover to maximize the incubating adult visibility, but many studies suggest a trade-off between nest-crypsis and predator detection strategies. However, this trade-off has not been explored in detail because methods used so far do not allow estimating the visibility with regards to critical factors such as slope or plant permeability to vision. Here, we tested the hypothesis that Kentish plovers select exposed sites according to a predator detection strategy, and the hypothesis that more concealed nests survive longer according to a crypsis strategy. To this end, we obtained an accurate estimation of the incubating adult's field of vision through a custom built inverted periscope. Our results showed that plovers selected nest sites with higher visibility than control points randomly selected with regards to humans and dogs, although nests located in sites with higher vegetation cover survived longer. In addition, the flushing distance (i.e., the distance at which incubating adults leave the nest when they detect a potential predator) decreased with vegetation cover. Consequently, the advantages of concealing the nest were limited by the ability to detect predators, thus indirectly supporting the existence of the trade-off between crypsis and predator detection. Finally, human disturbance also constrained nest choice, forcing plovers to move to inland sites that were less suitable because of higher vegetation cover, and modulated flushing behavior, since plovers that were habituated to humans left their nests closer to potential predators. This constraint on the width of suitable breeding habitat is particularly relevant for the conservation of Kentish Plover in sand beaches, especially under the current context of coastal regression and increase of recreational activities. PMID:25208045

The Distribution of Nesting White-bellied Sea-eagle (Haliaeetus leucogaster) in Penang National Park, Malaysia: Conservation and Management Issues.

PubMed

Azman, Nur Munira; Zainudin, Mohd Syafiq Masduqi Mohd; Sah, Shahrul Anuar Mohd; Latip, Nurul Salmi Abdul

2013-12-01

Taman Negara Pulau Pinang (Penang National Park) is the only site on Pulau Pinang that supports a large population of the White-bellied Sea-eagle (WBSE) Haliaeetus leucogaster; however, the nesting sites of WBSEs have not been widely studied. As information on the location of WBSE nesting sites is very important for conservation works by local authorities, the objective of this study was to determine the distribution of nesting WBSEs in the coastal dipterocarp forest of Penang National Park. Surveys were conducted from December 2007 to July 2008 and October 2008 to April 2009, covering the breeding season of the species (September-July). The nesting sites were observed by boat along the coastline of Penang National Park and by performing ground surveys along the seashore at accessible areas; the nest survey was conducted three days/month from 0900 to 1500. A total of 34 WBSE nesting sites was located. Most of the occupied nests (seven nests) were found at Muka Head and Pantai Kerachut areas, which exhibit the densest concentration of occupied WBSE habitat in Penang National Park. WBSEs preferred to build their nests around Muka Head, which could be due to the frequent occurrence of whirlpools in the water body around that area. Aquatic animals, such as sea snakes and fish, stunned by the whirlpools would emerge to the sea surface, facilitating the foraging and feeding of WBSEs. Our results indicate that it is important to maintain and improve areas of suitable nesting habitat for WBSEs. Management actions should include (1) the yearly monitoring of known breeding sites throughout Penang National Park during the breeding season to determine breeding success over time, (2) recognising the critical habitat or nest-site selection of WBSEs, (3) establishment of a buffer zone surrounding nesting sites and potential habitat from human disturbance, and (4) encouraging on-going research to further understand this species.

The effect of local and landscape-level characteristics on the abundance of forest birds in early-successional habitats during the post-fledging season in western Massachusetts

Treesearch

Michelle A. Labbe; David I. King; Tim A. Mousseau

2014-01-01

Many species of mature forest-nesting birds ("forest birds") undergo a pronounced shift in habitat use during the post-fledging period and move from their forest nesting sites into areas of early-successional vegetation. Mortality is high during this period, thus understanding the resource requirements of post-fledging birds has implications for conservation...

Population size and trends for nesting ospreys in northwestern Mexico: Region-wide surveys, 1977, 1992/1993 and 2006

USGS Publications Warehouse

Henny, Charles J.; Anderson, Daniel W.; Vera, Aradit Castellanos; Carton, Jean-Luc E.

2007-01-01

We used a double-sampling technique (air plus ground survey) in 2006, with partial double coverage, to estimate the present size of the osprey (Pandion haliaetus) nesting population in northwestern Mexico. With the exception of Natividad, Cedros, and San Benito Islands along the Pacific Coast of Baja California, all three excluded from our coverage in 2006 due to fog, this survey was a repeat of previous surveys conducted by us with the same protocol in 1977 and 1992/1993 (Baja California surveyed in 1992, Sonora and Sinaloa 1993), allowing for estimates of regional population trends. Population estimates at the 'time of aerial survey' include those nesting, but missed from the air. The population estimate for our coverage area in 2006 was 1,343 nesting pairs, or an 81% increase since 1977, but only a 3% increase since 1992/1993. The population on the Gulf side of Baja California generally remained stable during the three surveys (255, 236 and 252 pairs, respectively). The overall Midriff Islands population remained similar from 1992/1993 (308 pairs) to 2006 (289 pairs), but with notable population changes on the largest two islands (Isla Angel de la Guarda: 45 to 105 pairs [+ 60 pairs]; Isla Tiburon: 164 to 109 pairs [- 55 pairs, or -34%]). The estimated osprey population on the Sonora mainland decreased in a manner similar to adjacent Isla Tiburon, i.e., by 26%, from 214 pairs in 1993 to 158 pairs in 2006. In contrast, the population in Sinaloa, which had increased by 150% between 1977 and 1993, grew again by 58% between 1993 and 2006, from 180 to 285 pairs. Our survey confirmed previously described patterns of rapid population changes at a local level, coupled with apparent shifts in spatial distribution. The large ground nesting population that until recently nested on two islands in San Ignacio Lagoon was no longer present on the islands in 2006, but an equivalent number of pairs were found to the north and south of the lagoon, nesting in small towns and along adjoining power-lines, with no overall change in population size for that general area (198 pairs in 1992; 199 in 2006). Use of artificial nesting structures was 4.3% in 1977 and 6.2% in 1992/1993, but jumped to 26.4% in 2006. Use of power poles poses a risk of electrocution to ospreys as well as causes power outages and fires; modification of power poles to safely accommodate osprey nests has been successful in many countries.

Presence of Rhodnius ecuadoriensis in sylvatic habitats in the southern highlands (Loja Province) of Ecuador.

PubMed

Grijalva, M J; Villacis, A G

2009-05-01

The main vectors of Chagas disease in Ecuador are Triatoma dimidiata and Rhodnius ecuadoriensis. The latter species occupies domestic and peridomestic habitats, as well as sylvatic ecotopes--particularly associated with Phytelephas aequatorialis palm trees--in the western coastal region of Ecuador. In the southern highlands, however, such palm tree habitats are uncommon, and sylvatic populations of R. ecuadoriensis have not previously been reported to date. This study was carried out in five rural communities in Loja Province in southern Ecuador, where manual triatomine searches were conducted in various sylvatic habitats. A total of 81 squirrel nests (Sciurus stramineus) and > 200 bird nests and other habitats were searched. One hundred three R. ecuadoriensis individuals were found in 11 squirrel nests (infestation index = 13.6%, density = 2 bugs per nest searched, crowding = 9.5 bugs per infested nest, colonization index = 72.7% of infested nests with nymphs). No triatomines were found in bird nests or other sylvatic habitats. The presence of sylvatic R. ecuadoriensis in the southern highlands of Ecuador has important implications for the long-term control of Chagas disease in the region because of the possibility of reinfestation of dwellings after insecticide-based control interventions.

The influence of a hot environment on parental cooperation of a ground-nesting shorebird, the Kentish plover Charadrius alexandrinus

PubMed Central

2010-01-01

Background Parental care often increases offspring survival, but is costly to the parents. A trade-off between the cost and benefit of care is expected, so that when care provisioning by both parents is essential for the success of young, for instance in extremely cold or hot environments, the parents should rear their young together. We investigated the latter hypothesis in a ground nesting shorebird, the Kentish plover Charadrius alexandrinus in an extremely hot environment, the Arabian Desert. Midday ground temperature was often above 50°C in our study site in Abu Dhabi (United Arab Emirates), thus leaving the eggs unattended even for a few minute risks overheating and death of embryos. Results Through the use of video surveillance systems we recorded incubation routines of male and female Kentish plovers at 28 nests over a full day (24 h). We show that ambient temperature had a significant influence on incubation behaviour of both sexes, and the relationships are often non-linear. Coordinated incubation between parents was particularly strong in midday with incubation shared approximately equally between the male and the female. The enhanced biparental incubation was due to males increasing their nest attendance with ambient temperature. Conclusions Our results suggest biparental care is essential during incubation in the Kentish plover in extremely hot environments. Shared incubation may also help the parents to cope with heat stress themselves: they can relieve each other frequently from incubation duties. We suggest that once the eggs have hatched the risks associated with hot temperature are reduced: the chicks become mobile, and they gradually develop thermoregulation. When biparental care of young is no longer essential one parent may desert the family. The relaxed demand of the offspring may contribute to the diverse breeding systems exhibited by many shorebirds. PMID:20148101

Landscape alterations influence differential habitat use of nesting buteos and ravens within sagebrush ecosystem: implications for transmission line development

USGS Publications Warehouse

Coates, Peter S.; Howe, Kristy B.; Casazza, Michael L.; Delehanty, David J.

2014-01-01

A goal in avian ecology is to understand factors that influence differences in nesting habitat and distribution among species, especially within changing landscapes. Over the past 2 decades, humans have altered sagebrush ecosystems as a result of expansion in energy production and transmission. Our primary study objective was to identify differences in the use of landscape characteristics and natural and anthropogenic features by nesting Common Ravens (Corvus corax) and 3 species of buteo (Swainson's Hawk [Buteo swainsoni], Red-tailed Hawk [B. jamaicensis], and Ferruginous Hawk [B. regalis]) within a sagebrush ecosystem in southeastern Idaho. During 2007–2009, we measured multiple environmental factors associated with 212 nest sites using data collected remotely and in the field. We then developed multinomial models to predict nesting probabilities by each species and predictive response curves based on model-averaged estimates. We found differences among species related to nesting substrate (natural vs. anthropogenic), agriculture, native grassland, and edge (interface of 2 cover types). Most important, ravens had a higher probability of nesting on anthropogenic features (0.80) than the other 3 species (Artemisia spp.), favoring increased numbers of nesting ravens and fewer nesting Ferruginous Hawks. Our results indicate that habitat alterations, fragmentation, and forthcoming disturbances anticipated with continued energy development in sagebrush steppe ecosystems can lead to predictable changes in raptor and raven communities.

Nesting ecology of boreal forest birds following a massive outbreak of spruce beetles

USGS Publications Warehouse

Matsuoka, S.M.; Handel, C.M.

2007-01-01

We studied breeding dark-eyed juncos (Junco hyemalis), yellow-rumped warblers (Dendroica coronata), and spruce-nesting birds from 1997 to 1998 among forests with different levels of spruce (Picea spp.) mortality following an outbreak of spruce beetles (Dendroctonus rufipennis) in Alaska, USA. We identified species using live and beetle-killed spruce for nest sites and monitored nests to determine how the outbreak influenced avian habitat selection and reproduction. We tested predictions that 1) nesting success of ground-nesting juncos would increase with spruce mortality due to proliferation of understory vegetation available to conceal nests from predators, 2) nesting success of canopy-nesting warblers would decrease with spruce mortality due to fewer live spruce in which to conceal nests, and 3) both species would alter nest-site selection in response to disturbance. Juncos did not benefit from changes in understory vegetation; nesting success in highly disturbed stands (46%) was comparable to that in undisturbed habitats throughout their range. In stands with low spruce mortality, nesting success of juncos was low (5%) and corresponded with high densities of red squirrels (Tamiasciurus hudsonicus). Yellow-rumped warblers nested exclusively in spruce, but success did not vary with spruce mortality. As disturbance increased, nesting warblers switched from selecting forest patches with high densities of live white spruce (Picea glauca) to patches with beetle-killed spruce. Warblers also placed nests in large-diameter live or beetle-killed spruce, depending on which was more abundant in the stand, with no differences in nesting success. Five of the 12 other species of spruce-nesting birds also used beetle-killed spruce as nest sites. Because beetle-killed spruce can remain standing for >50 years, even highly disturbed stands provide an important breeding resource for boreal forest birds. We recommend that boreal forest managers preserve uncut blocks of infested forest within managed forest landscapes and practice partial harvest of beetle-killed spruce rather than commercial clear-cutting of infested stands in order to sustain breeding bird populations until natural reforestation occurs. Because breeding densities do not always reflect fitness, assessing impacts of a massive natural disturbance should include measuring impacts of changes in vegetation on both reproductive success and predator–prey dynamics.

Fitness consequences of nest desertion in an endangered host, the least Bell's vireo

USGS Publications Warehouse

Kus, Barbara E.

2002-01-01

Recent analyses of the impact of cowbird parasitism on host productivity suggest that while parasitism reduces productivity on a per-nest basis, the ability of pairs to desert parasitized nests and renest allows them to achieve productivity comparable to that of unparasitized pairs. This has implications for the management of several endangered species that are highly vulnerable to parasitism and consequently the target of cowbird control programs. I calculated seasonal nesting effort (number of nests per pair) and productivity of 568 pairs of Least Bell's Vireos (Vireo bellii pusillus) monitored over 11 years at the San Luis Rey River in San Diego County, California (where cowbird trapping has reduced, but not eliminated, parasitism), assigning pairs to one of three groups: (1) deserters, (2) rescued (parasitized pairs with nests “rescued” from probable failure by the removal of cowbird eggs), and (3) unparasitized. Parasitized pairs attempted significantly more nests per season than did unparasitized pairs, with deserters producing more nests than rescued pairs. However, productivity of deserting pairs was significantly lower than that of both rescued and unparasitized pairs, largely because subsequent nests of deserting pairs were also parasitized. Seasonal productivity of rescued and unparasitized pairs was comparable, indicating that in this species, reduction of cowbird impacts through nest manipulation to remove cowbird eggs is effective. Desertion by Least Bell's Vireos does not appear to be an adequate natural defense against parasitism, suggesting the need for continued cowbird control while vireo populations are re-established.

Nesting tree characteristics of heronry birds of urban ecosystems in peninsular India: implications for habitat management

PubMed Central

Sinu, Palatty Allesh

2017-01-01

Abstract Wetland ecosystems, particularly the mangrove forest, are the primary wild habitat of heronry birds. However, urban ecosystems have become a favorite breeding habitat of these birds. To provide inputs into the habitat management for conservation of these birds, we investigated the quantitative and qualitative characteristics of nesting trees of heronry birds in the urban environment of the North Kerala region of peninsular India. Census on nesting trees was done in 3 major microhabitats of the urban ecosystem: avenues of national highways and towns, nonresidential plots, and residential areas apart from the mangrove islets in the peri-urban locality. The study found that 174 trees of 22 species hosted 1,928 heronry bird nests in the urban habitats; mangrove forests, although plentiful in the study area, hosted only about 20% of the total nests encountered in the study. Rain trees Samanea saman (43.7%) were the most available nesting tree. The greatest number of nests and nesting trees were encountered on the roads of urban areas, followed by nonresidential areas and residential areas. The differences in the observed frequencies of nesting trees in 3 microhabitats and in 3 types of roads (national highways > state highways > small pocket road) were significant. Canopy spread, girth size, and quality of the trees predicted the tree selection of the heronry birds in urban environments. Therefore, we recommend proper management and notification of the identified nesting trees as protected sites for the conservation of herorny birds. PMID:29492020

Nesting tree characteristics of heronry birds of urban ecosystems in peninsular India: implications for habitat management.

PubMed

Roshnath, Ramesh; Sinu, Palatty Allesh

2017-12-01

Wetland ecosystems, particularly the mangrove forest, are the primary wild habitat of heronry birds. However, urban ecosystems have become a favorite breeding habitat of these birds. To provide inputs into the habitat management for conservation of these birds, we investigated the quantitative and qualitative characteristics of nesting trees of heronry birds in the urban environment of the North Kerala region of peninsular India. Census on nesting trees was done in 3 major microhabitats of the urban ecosystem: avenues of national highways and towns, nonresidential plots, and residential areas apart from the mangrove islets in the peri-urban locality. The study found that 174 trees of 22 species hosted 1,928 heronry bird nests in the urban habitats; mangrove forests, although plentiful in the study area, hosted only about 20% of the total nests encountered in the study. Rain trees Samanea saman (43.7%) were the most available nesting tree. The greatest number of nests and nesting trees were encountered on the roads of urban areas, followed by nonresidential areas and residential areas. The differences in the observed frequencies of nesting trees in 3 microhabitats and in 3 types of roads (national highways > state highways > small pocket road) were significant. Canopy spread, girth size, and quality of the trees predicted the tree selection of the heronry birds in urban environments. Therefore, we recommend proper management and notification of the identified nesting trees as protected sites for the conservation of herorny birds.

Firewalls in bee nests—survival value of propolis walls of wild Cape honeybee ( Apis mellifera capensis)

NASA Astrophysics Data System (ADS)

Tribe, Geoff; Tautz, Jürgen; Sternberg, Karin; Cullinan, Jenny

2017-04-01

The Cape bee is endemic to the winter rainfall region of South Africa where fires are an integral part of the ecology of the fynbos (heathland) vegetation. Of the 37 wild nests in pristine Peninsula Sandstone Fynbos in the Cape Point section of Table Mountain National Park that have been analyzed so far, only 22 could be accessed sufficiently to determine the existence of a propolis wall of which 68% had propolis walls which entirely enclosed their openings. The analysis of the 37 wild nests revealed that 78% occurred under boulders or in clefts within rocks, 11% in the ground, 8% in tree cavities, and 3% within shrubs. The analysis of 17 of these nests following a fire within the park revealed that the propolis walls materially protected the nests and retarded the fire with all the colonies surviving. The bees responded to the smoke by imbibing honey and retreating to the furthest recess of their nest cavity. The bees were required to utilize this honey for about 3 weeks after which fire-loving plants appeared and began flowering. Considerable resources were utilized in the construction of the propolis walls, which ranged in thickness from 1.5 to 40 mm (mean 5 mm). Its physical environment determines the nesting behavior of the Cape bee. The prolific use of propolis serves to insulate the nest from extremes of temperature and humidity, restricts entry, camouflages the nest, and acts as an effective fire barrier protecting nests established mostly under rocks in vegetation subjected to periodic fires.

Influences of Species Interactions With Aggressive Ants and Habitat Filtering on Nest Colonization and Community Composition of Arboreal Twig-Nesting Ants.

PubMed

Philpott, Stacy M; Serber, Zachary; De la Mora, Aldo

2018-04-05

Ant community assembly is driven by many factors including species interactions (e.g., competition, predation, parasitism), habitat filtering (e.g., vegetation differences, microclimate, food and nesting resources), and dispersal. Canopy ant communities, including dominant and twig-nesting ants, are structured by all these different factors, but we know less about the impacts of species interactions and habitat filters acting at the colonization or recruitment stage. We examined occupation of artificial twig nests placed in shade trees in coffee agroecosystems. We asked whether species interactions-aggression from the dominant canopy ant, Azteca sericeasur Longino (Hymenoptera: Formicidae)-or habitat filtering-species of tree where nests were placed or surrounding vegetation-influence colonization, species richness, and community composition of twig-nesting ants. We found 20 species of ants occupying artificial nests. Nest occupation was lower on trees with A. sericeasur, but did not differ depending on tree species or surrounding vegetation. Yet, there were species-specific differences in occupation depending on A. sericeasur presence and tree species. Ant species richness did not vary with A. sericeasur presence or tree species. Community composition varied with A. sericeasur presence and surrounding vegetation. Our results suggest that species interactions with dominant ants are important determinants of colonization and community composition of twig-nesting ants. Habitat filtering at the level of tree species did not have strong effects on twig-nesting ants, but changes in coffee management may contribute to differences in community composition with important implications for ant conservation in agricultural landscapes, as well as biological control of coffee pests.

Electrocution

USGS Publications Warehouse

Thomas, N.J.

1999-01-01

Power lines and power poles present a potential electrocution hazard to wild birds. Many birds, especially raptors, select power poles for perching, and, sometimes, for nesting (Figs. 50.1–3). If a bird’s appendages bridge the gap between two energized parts or between an energized and a grounded metal part, electricity flows through the “bridge” that is filling the gap and the bird is electrocuted. Most commonly, birds are electrocuted where conducting wires (conductors) are placed closer together than the wingspan of birds that frequent the poles (Fig. 50.2). Feathers are poor electrical conductors, but if contact is made between points on the skin, talons, or beak, or if the feathers are wet, conduction can occur. Common anatomical sites of contact include conduction between the wrists of each wing or between the skin of one wing and a foot or leg. The resulting shock causes severe, usually fatal, cardiovascular injury. Because conductors on distribution lines are placed closer together than high voltage transmission lines, birds are more frequently electrocuted on distribution lines despite their lower voltage. In addition to one to three conductors, power poles may also carry ground wires, transformers, or grounded metal crossarm braces. Complicated wiring configurations that put multiple energized and grounded metal parts near attractive perching or nesting sites are the most hazardous configurations (Fig. 50.3).

Population genetic analysis of Mountain Plover using mitochondrial DNA sequence data

USGS Publications Warehouse

Oyler-McCance, S.J.; St. John, J.; Knopf, F.L.; Quinn, T.W.

2005-01-01

Mountain Plover (Charadrius montanus) distribution and abundance have been reduced drastically in the past 30 years and the conversion of shortgrass prairie to agriculture has caused breeding populations to become geographically isolated. This, coupled with the fact that Mountain Plovers are thought to show fidelity to breeding grounds, leads to the prediction that the isolated breeding populations would be genetically distinct. This pattern, if observed, would have important management implications for a species at risk of extinction. Our study examined genetic variation at two mitochondrial regions for 20–30 individuals from each of four breeding sites. We found no evidence of significant population differentiation in the data from the control region or the ATPase 6/8 region. Nested-clade analysis revealed no relationship between haplotype phylogeny, and geography among the 47 control region haplotypes. In the ATPase 6/8 region, however, one of the two clades provided information suggesting that, historically, there has been continuous range expansion. Analysis of mismatch distributions and Tajima's D suggest that the Mountain Plover underwent a population expansion, following the Pleistocene glacial period. To explain the lack of detectable genetic differentiation among populations, despite their geographic isolation and fidelity to breeding locations, we speculate that there is sufficient female-mediated gene flow to homogenize gene pools among populations. Such gene flow might ensue if pair bonds are formed in mixed flocks on wintering grounds rather than on the summer breeding grounds.

Camouflage predicts survival in ground-nesting birds

PubMed Central

Troscianko, Jolyon; Wilson-Aggarwal, Jared; Stevens, Martin; Spottiswoode, Claire N.

2016-01-01

Evading detection by predators is crucial for survival. Camouflage is therefore a widespread adaptation, but despite substantial research effort our understanding of different camouflage strategies has relied predominantly on artificial systems and on experiments disregarding how camouflage is perceived by predators. Here we show for the first time in a natural system, that survival probability of wild animals is directly related to their level of camouflage as perceived by the visual systems of their main predators. Ground-nesting plovers and coursers flee as threats approach, and their clutches were more likely to survive when their egg contrast matched their surrounds. In nightjars – which remain motionless as threats approach – clutch survival depended on plumage pattern matching between the incubating bird and its surrounds. Our findings highlight the importance of pattern and luminance based camouflage properties, and the effectiveness of modern techniques in capturing the adaptive properties of visual phenotypes. PMID:26822039

Camouflage predicts survival in ground-nesting birds.

PubMed

Troscianko, Jolyon; Wilson-Aggarwal, Jared; Stevens, Martin; Spottiswoode, Claire N

2016-01-29

Evading detection by predators is crucial for survival. Camouflage is therefore a widespread adaptation, but despite substantial research effort our understanding of different camouflage strategies has relied predominantly on artificial systems and on experiments disregarding how camouflage is perceived by predators. Here we show for the first time in a natural system, that survival probability of wild animals is directly related to their level of camouflage as perceived by the visual systems of their main predators. Ground-nesting plovers and coursers flee as threats approach, and their clutches were more likely to survive when their egg contrast matched their surrounds. In nightjars - which remain motionless as threats approach - clutch survival depended on plumage pattern matching between the incubating bird and its surrounds. Our findings highlight the importance of pattern and luminance based camouflage properties, and the effectiveness of modern techniques in capturing the adaptive properties of visual phenotypes.

Probability of detection of nests and implications for survey design

USGS Publications Warehouse

Smith, P.A.; Bart, J.; Lanctot, Richard B.; McCaffery, B.J.; Brown, S.

2009-01-01

Surveys based on double sampling include a correction for the probability of detection by assuming complete enumeration of birds in an intensively surveyed subsample of plots. To evaluate this assumption, we calculated the probability of detecting active shorebird nests by using information from observers who searched the same plots independently. Our results demonstrate that this probability varies substantially by species and stage of the nesting cycle but less by site or density of nests. Among the species we studied, the estimated single-visit probability of nest detection during the incubation period varied from 0.21 for the White-rumped Sandpiper (Calidris fuscicollis), the most difficult species to detect, to 0.64 for the Western Sandpiper (Calidris mauri), the most easily detected species, with a mean across species of 0.46. We used these detection probabilities to predict the fraction of persistent nests found over repeated nest searches. For a species with the mean value for detectability, the detection rate exceeded 0.85 after four visits. This level of nest detection was exceeded in only three visits for the Western Sandpiper, but six to nine visits were required for the White-rumped Sandpiper, depending on the type of survey employed. Our results suggest that the double-sampling method's requirement of nearly complete counts of birds in the intensively surveyed plots is likely to be met for birds with nests that survive over several visits of nest searching. Individuals with nests that fail quickly or individuals that do not breed can be detected with high probability only if territorial behavior is used to identify likely nesting pairs. ?? The Cooper Ornithological Society, 2009.

Impact of nest predators, competitors, and ectoparasites on Pearly-eyed Thrashers, with comments on the potential implications for Puerto Rican Parrot recovery

Treesearch

Wayne J. Arendt

2000-01-01

Over the past 17 years, research on a rain forest population of the Pearly-eyed Thrasher (Margarops fuscatus), with additional observations on nesting Puerto Rican Parrots (Amazona vittata) within the Sierra de Luquillo, Puerto Rico, has shown that reproductive success of thrashers and parrots is often greatly reduced as a result of the additive effects of a diverse...

A Miocene termite nest from southern Argentina and its paleoclimatological implications

USGS Publications Warehouse

Bown, Thomas M.; Laza, José H.

1990-01-01

A Miocene termitarium attributable to the extant termite Syntermes (Isoptera: Termitidae, Nasutitermitinae) is the first fossil termite nest reported from South America and possibly the oldest record of the Isoptera from that continent. The fossil remains consist of most of the periphery of the subterranean portion of a single Syntermes nest, including chambers and both major and minor systems of anastomosed galleries. The nest occurs in the upper part of a mature paleosol near the base of the pyroclastic and eolian Miocene Pinturas Formation.A new ichnogenus and ichnospecies, Syntermesichnus fon‐tanae, is proposed for this distinctive trace fossil. It differs from nests constructed by other members of the Nasutitermitinae in its architectural organization and its large size. The type locality is situated 20° south of the southernmost dispersion of extant Syntermes.The modern distribution of this termite is wholly neotropical, suggesting that at least part of southern Patagonia experienced a tropical to subtropical climate as late as the late‐early Miocene.

KSC-06pd0847

NASA Image and Video Library

2006-05-17

KENNEDY SPACE CENTER, FLA. -- A mother osprey (left) sits protectively next to one of her chicks in the nest situated at the top of a pole in the parking lot at the NASA News Center at Kennedy Space Center. Behind the nest can be seen the immense flag painted on the side of the Vehicle Assembly Building. This is the third year the ospreys have raised a family at the News Center. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge, which shares a boundary with the Center. Photo credit: NASA/George Shelton

KSC-2009-1510

NASA Image and Video Library

2009-01-31

CAPE CANAVERAL, Fla. – An osprey carries its food in its talons as it flies to its nest near the NASA News Center at NASA's Kennedy Space Center in Florida. The osprey, also called fish hawk, is well adapted for capturing fish, which make up its entire diet. The soles of the birds' feet are equipped with sharp, spiny projections that give the bird a firm grip on its slippery prey. Nests of ospreys are bulky masses of sticks and debris placed in a tree, on rocks, flat ground or telephone poles. Many nests exist around the Launch Complex 39 Area at the center. The bird is one of more than 500 species of birds that co-exist at the center and the surrounding Merritt Island National Wildlife Refuge. Photo credit: NASA/Ben Smelgelsky

Grassland bird productivity in warm season grass fields in southwest Wisconsin

USGS Publications Warehouse

Byers, Carolyn M.; Ribic, Christine; Sample, David W.; Dadisman, John D.; Guttery, Michael

2017-01-01

Surrogate grasslands established through federal set-aside programs, such as U.S. Department of Agriculture's Conservation Reserve Program (CRP), provide important habitat for grassland birds. Warm season grass CRP fields as a group have the potential for providing a continuum of habitat structure for breeding birds, depending on how the fields are managed and their floristic composition. We studied the nesting activity of four obligate grassland bird species, Bobolink (Dolichonyx oryzivorus), Eastern Meadowlark (Sturnella magna), Grasshopper Sparrow (Ammodramus savannarum), and Henslow's Sparrow (A. henslowii), in relation to vegetative composition and fire management in warm season CRP fields in southwest Wisconsin during 2009–2011. Intraspecific variation in apparent nest density was related to the number of years since the field was burned. Apparent Grasshopper Sparrow nest density was highest in the breeding season immediately following spring burns, apparent Henslow's Sparrow nest density was highest 1 y post burn, and apparent Bobolink and Eastern Meadowlark nest densities were higher in post fire years one to three. Grasshopper Sparrow nest density was highest on sites with more diverse vegetation, specifically prairie forbs, and on sites with shorter less dense vegetation. Bobolink, Eastern Meadowlark, and Henslow's Sparrow apparent nest densities were higher on sites with deeper litter; litter was the vegetative component that was most affected by spring burns. Overall nest success was 0.487 for Bobolink (22 d nesting period), 0.478 for Eastern Meadowlark (25 d nesting period), 0.507 for Grasshopper Sparrow (22 d nesting period), and 0.151 for Henslow's Sparrow (21 d nesting period). The major nest predators were grassland-associated species: thirteen-lined ground squirrel (Ictidomys tridecemlineatus), striped skunk (Mephitis mephitis), milk snake (Lampropeltis triangulum), American badger (Taxidea taxus), and western fox snake (Elaphe vulpina). Overall depredation rate was not affected by the number of years since the site had been burned. The diversity of vegetation on warm season CRP fields created by management using fire provides a continuum of structure for obligate grassland birds to use for breeding and habitat for a diversity of nest predators.

Climate change has indirect effects on resource use and overlap among coexisting bird species with negative consequences for their reproductive success

USGS Publications Warehouse

Martin, Thomas E.; Auer, Sonya K.

2013-01-01

Climate change can modify ecological interactions, but whether it can have cascading effects throughout ecological networks of multiple interacting species remains poorly studied. Climate-driven alterations in the intensity of plant–herbivore interactions may have particularly profound effects on the larger community because plants provide habitat for a wide diversity of organisms. Here we show that changes in vegetation over the last 21 years, due to climate effects on plant–herbivore interactions, have consequences for songbird nest site overlap and breeding success. Browsing-induced reductions in the availability of preferred nesting sites for two of three ground nesting songbirds led to increasing overlap in nest site characteristics among all three bird species with increasingly negative consequences for reproductive success over the long term. These results demonstrate that changes in the vegetation community from effects of climate change on plant–herbivore interactions can cause subtle shifts in ecological interactions that have critical demographic ramifications for other species in the larger community.

Redefining reproductive success in songbirds: Moving beyond the nest success paradigm

USGS Publications Warehouse

Streby, Henry M.; Refsnider, Jeanine M.; Andersen, David E.

2014-01-01

One of the most commonly estimated parameters in studies of songbird ecology is reproductive success, as a measure of either individual fitness or population productivity. Traditionally, the “success” in reproductive success refers to whether, or how many, nestlings leave nests. Here, we advocate that “reproductive success” in songbirds be redefined as full-season productivity, or the number of young raised to independence from adult care in a breeding season. A growing body of evidence demonstrates interdependence between nest success and fledgling survival, and emphasizes that data from either life stage alone can produce misleading measures of individual fitness and population productivity. Nest success, therefore, is an insufficient measure of reproductive success, and songbird ecology needs to progress beyond this long-standing paradigm. Full-season productivity, an evolutionarily rational measure of reproductive success, provides the framework for appropriately addressing unresolved questions about the adaptive significance of many breeding behaviors and within which effective breeding-grounds conservation and management can be designed.

Swooping in the Suburbs; Parental Defence of an Abundant Aggressive Urban Bird against Humans.

PubMed

Lees, Daniel; Sherman, Craig D H; Maguire, Grainne S; Dann, Peter; Cardilini, Adam P A; Weston, Michael A

2013-08-13

Masked Lapwings, Vanellus miles, often come into 'conflict' with humans, because they often breed in close proximity to humans and actively defend their ground nests through aggressive behaviour, which typically involves swooping. This study examined whether defensive responses differed when nesting birds were confronted with different human stimuli ('pedestrian alone' vs. 'person pushing a lawn mower' approaches to nests) and tested the effectiveness of a commonly used deterrent (mock eyes positioned on the top or back of a person's head) on the defensive response. Masked Lapwings did not swoop closer to a person with a lawn mower compared with a pedestrian, but flushed closer and remained closer to the nest in the presence of a lawn mower. The presence of eye stickers decreased (pedestrians) and increased (lawn mowers) swooping behaviour. Masked Lapwings can discriminate between different human activities and adjust their defensive behaviour accordingly. We also conclude that the use of eye stickers is an effective method to mitigate the human-lapwing 'conflict' in some, but not all, circumstances.

Making Your School Site an Environmental Smorgasboard.

ERIC Educational Resources Information Center

Carman, Sam

1986-01-01

Describes ways to enhance a school's outdoor facilities to provide more educational opportunities: nesting boxes, ground water monitoring holes, nature's "swamp shop," soil studies, weather stations, wildlife habitat improvement, forestry practices, aquatic resources, archaeological dig sites, horticulture demonstration areas, outdoor…

Housing Projects.

ERIC Educational Resources Information Center

Schmalz, Georgann

1985-01-01

Building specifications for birdhouses (nesting boxes) are given for 11 species (chickadee, titmouse, nuthatch, Carolina wren, house wren, downy woodpecker, hairy woodpecker, flicker, bluebird, screech owl, and wood duck) including length, width, depth, entrance diameter, and height above the ground. Pointers for construction, materials, and…

Selection of nest-site habitat by interior least terns in relation to sandbar construction

USGS Publications Warehouse

Sherfy, M.H.; Stucker, J.H.; Buhl, D.A.

2012-01-01

Federally endangered interior least terns (Sternula antillarum) nest on bare or sparsely vegetated sandbars on midcontinent river systems. Loss of nesting habitat has been implicated as a cause of population declines, and managing these habitats is a major initiative in population recovery. One such initiative involves construction of mid-channel sandbars on the Missouri River, where natural sandbar habitat has declined in quantity and quality since the late 1990s. We evaluated nest-site habitat selection by least terns on constructed and natural sandbars by comparing vegetation, substrate, and debris variables at nest sites (na =a 798) and random points (na =a 1,113) in bare or sparsely vegetated habitats. Our logistic regression models revealed that a broader suite of habitat features was important in nest-site selection on constructed than on natural sandbars. Odds ratios for habitat variables indicated that avoidance of habitat features was the dominant nest-site selection process on both sandbar types, with nesting terns being attracted to nest-site habitat features (gravel and debris) and avoiding vegetation only on constructed sandbars, and avoiding silt and leaf litter on both sandbar types. Despite the seemingly uniform nature of these habitats, our results suggest that a complex suite of habitat features influences nest-site choice by least terns. However, nest-site selection in this social, colonially nesting species may be influenced by other factors, including spatial arrangement of bare sand habitat, proximity to other least terns, and prior habitat occupancy by piping plovers (Charadrius melodus). We found that nest-site selection was sensitive to subtle variation in habitat features, suggesting that rigor in maintaining habitat condition will be necessary in managing sandbars for the benefit of least terns. Further, management strategies that reduce habitat features that are avoided by least terns may be the most beneficial to nesting least terns. ?? 2011 The Wildlife Society.

Selection of nest-site habitat by interior least terns in relation to sandbar construction

USGS Publications Warehouse

Sherfy, Mark H.; Stucker, Jennifer H.; Buhl, Deborah A.

2012-01-01

Federally endangered interior least terns (Sternula antillarum) nest on bare or sparsely vegetated sandbars on midcontinent river systems. Loss of nesting habitat has been implicated as a cause of population declines, and managing these habitats is a major initiative in population recovery. One such initiative involves construction of mid-channel sandbars on the Missouri River, where natural sandbar habitat has declined in quantity and quality since the late 1990s. We evaluated nest-site habitat selection by least terns on constructed and natural sandbars by comparing vegetation, substrate, and debris variables at nest sites (n = 798) and random points (n = 1,113) in bare or sparsely vegetated habitats. Our logistic regression models revealed that a broader suite of habitat features was important in nest-site selection on constructed than on natural sandbars. Odds ratios for habitat variables indicated that avoidance of habitat features was the dominant nest-site selection process on both sandbar types, with nesting terns being attracted to nest-site habitat features (gravel and debris) and avoiding vegetation only on constructed sandbars, and avoiding silt and leaf litter on both sandbar types. Despite the seemingly uniform nature of these habitats, our results suggest that a complex suite of habitat features influences nest-site choice by least terns. However, nest-site selection in this social, colonially nesting species may be influenced by other factors, including spatial arrangement of bare sand habitat, proximity to other least terns, and prior habitat occupancy by piping plovers (Charadrius melodus). We found that nest-site selection was sensitive to subtle variation in habitat features, suggesting that rigor in maintaining habitat condition will be necessary in managing sandbars for the benefit of least terns. Further, management strategies that reduce habitat features that are avoided by least terns may be the most beneficial to nesting least terns.

Loggerhead sea turtle environmental sex determination: implications of moisture and temperature for climate change based predictions for species survival.

PubMed

Wyneken, Jeanette; Lolavar, Alexandra

2015-05-01

It has been proposed that because marine turtles have environmentally determined sex by incubation temperature, elevated temperatures might skew sex ratios to unsustainable levels, leading to extinction. Elevated temperatures may also reduce availability of suitable nesting sites via sea level rise. Increased tropical storm activity can directly affect nest site moisture, embryonic development, and the probability that nests will survive. Here, we question some of these assumptions and review the limits of sex ratio estimates. Sea turtles may be more resilient to climate change than previously thought, in part because of hitherto unappreciated mechanisms for coping with variable incubation conditions. © 2015 Wiley Periodicals, Inc.

Ecology of a nesting red-shouldered hawk population

USGS Publications Warehouse

Stewart, R.E.

1949-01-01

An ecological study of a nesting Red-shouldered Hawk population was made over a 185 square mile area on the Coastal Plain of Maryland in 1947. The courting and nesting season extended from late February until late June.....During the nesting season a combination of fairly extensive flood-plain forest with adjacent clearings appears to meet the major ecological requirements of the Red-shouldered Hawk in this region. A total of 51 pairs was found in the study area, occupying about 42 square miles or 23% of the total area studied. The population density on the land that was suitable for this species was about 1 pair per .8 of a square mile, while the density for the entire study area would be only about 1 pair per 3.6 square miles.....Nests were spaced fairly evenly over most of the flood-plain forests, especially in areas where the width.of the flood plain was relatively constant. There was an inverse correlation between the width of the flood plain and the distances between nests in adjacent territories. The nests were all situated in fairly large trees and were from 28 feet to 77 feet above the ground, averaging 50. They were found in 14 different species of trees, all deciduous.....The Barred Owl and Red-shouldered Hawk were commonly associated together in the same lowland habitats. Other raptores were all largely restricted to upland habitats....The average number of young in 47 occupied nests following the hatching period was 2.7 with extremes of 1 and 4. Only 3 out of 52 nests (6%) were found deserted at this time....The food habits of nestling Red-shouldered Hawks are very diversified. They feed on many types of warm-blooded and cold-blooded vertebrates as well as invertebrates.

Seasonal trends in nesting leatherback turtle (Dermochelys coriacea) serum proteins further verify capital breeding hypothesis

PubMed Central

Perrault, Justin R.; Wyneken, Jeanette; Page-Karjian, Annie; Merrill, Anita; Miller, Debra L.

2014-01-01

Serum protein concentrations provide insight into the nutritional and immune status of organisms. It has been suggested that some marine turtles are capital breeders that fast during the nesting season. In this study, we documented serum proteins in neophyte and remigrant nesting leatherback sea turtles (Dermochelys coriacea). This allowed us to establish trends across the nesting season to determine whether these physiological parameters indicate if leatherbacks forage or fast while on nesting grounds. Using the biuret method and agarose gel electrophoresis, total serum protein (median = 5.0 g/dl) and protein fractions were quantified and include pre-albumin (median = 0.0 g/dl), albumin (median = 1.81 g/dl), α1-globulin (median = 0.90 g/dl), α2-globulin (median = 0.74 g/dl), total α-globulin (median = 1.64 g/dl), β-globulin (median = 0.56 g/dl), γ-globulin (median = 0.81 g/dl) and total globulin (median = 3.12 g/dl). The albumin:globulin ratio (median = 0.59) was also calculated. Confidence intervals (90%) were used to establish reference intervals. Total protein, albumin and total globulin concentrations declined in successive nesting events. Protein fractions declined at less significant rates or remained relatively constant during the nesting season. Here, we show that leatherbacks are most likely fasting during the nesting season. A minimal threshold of total serum protein concentrations of around 3.5–4.5 g/dl may physiologically signal the end of the season's nesting for individual leatherbacks. The results presented here lend further insight into the interaction between reproduction, fasting and energy reserves and will potentially improve the conservation and management of this imperiled species. PMID:27293623

Impacts of tree rows on grassland birds and potential nest predators: a removal experiment.

PubMed

Ellison, Kevin S; Ribic, Christine A; Sample, David W; Fawcett, Megan J; Dadisman, John D

2013-01-01

Globally, grasslands and the wildlife that inhabit them are widely imperiled. Encroachment by shrubs and trees has widely impacted grasslands in the past 150 years. In North America, most grassland birds avoid nesting near woody vegetation. Because woody vegetation fragments grasslands and potential nest predator diversity and abundance is often greater along wooded edge and grassland transitions, we measured the impacts of removing rows of trees and shrubs that intersected grasslands on potential nest predators and the three most abundant grassland bird species (Henslow's sparrow [Ammodramus henslowii], Eastern meadowlark [Sturnella magna], and bobolink [Dolichonyx oryzivorus]) at sites in Wisconsin, U.S.A. We monitored 3 control and 3 treatment sites, for 1 yr prior to and 3 yr after tree row removal at the treatment sites. Grassland bird densities increased (2-4 times for bobolink and Henslow's sparrow) and nesting densities increased (all 3 species) in the removal areas compared to control areas. After removals, Henslow's sparrows nested within ≤50 m of the treatment area, where they did not occur when tree rows were present. Most dramatically, activity by woodland-associated predators nearly ceased (nine-fold decrease for raccoon [Procyon lotor]) at the removals and grassland predators increased (up to 27 times activity for thirteen-lined ground squirrel [Ictidomys tridecemlineatus]). Nest success did not increase, likely reflecting the increase in grassland predators. However, more nests were attempted by all 3 species (175 versus 116) and the number of successful nests for bobolinks and Henslow's sparrows increased. Because of gains in habitat, increased use by birds, greater production of young, and the effective removal of woodland-associated predators, tree row removal, where appropriate based on the predator community, can be a beneficial management action for conserving grassland birds and improving fragmented and degraded grassland ecosystems.

Patterns of variation in clutch sizes in a guild of temperate-nesting dabbling ducks

USGS Publications Warehouse

Krapu, G.L.; Reynolds, R.E.; Sargeant, G.A.; Renner, R.W.

2004-01-01

Clutch sizes of temperate-nesting dabbling ducks vary widely within and between years. Biologists have long been interested in why such patterns exist but have had difficulty separating intrinsic effects from environmental influences. In an attempt to gain greater insight into the roles of intrinsic and environmental influences on clutch sizes of dabbling ducks, we compared clutch-size patterns of mallard, northern pintail, gadwall, northern shoveler, and blue-winged teal in North Dakota and South Dakota over a 3-year period. The study was conducted during 1993-1995 when wetland habitat conditions were exceptionally consistent within time intervals but varied widely from the onset to the end of the study. We found that clutch sizes of gadwall and blue-winged teal were significantly smaller at the onset of nesting in 1993, when water conditions remained relatively poor following a 5-year drought (1988-1992), and pintail clutch sizes were larger late in the breeding season in 1993 after wetland conditions became exceptionally productive following heavy rains in late May and June. These findings were associated with gadwall and teal relying primarily on nutrients acquired on the breeding grounds to produce early clutches, and pintails using an exceptionally high proportion of their body lipids to produce early clutches, making this species highly dependent on abundant local sources of lipids for clutches produced later. Mallard, pintail, and shoveler rely largely on endogenous lipids carried to the breeding grounds to produce early clutches, and at least in the years of study, clutch sizes exhibited minimal variation at the onset of nesting. Our findings, when examined in context with existing information, suggest that interspecific variation in clutch sizes results from innate differences in several traits -- including body size, diet, timing of lipid acquisition, and nesting-- that affect the amount of lipid available for egg production. Annual differences in clutch sizes of all five species were not significant when effects of annual variation in nest initiation dates was accounted for, reflecting the key role of environmental influences on intraspecific variation among years.

Analysis of sugarcane herbicides in marine turtle nesting areas and assessment of risk using in vitro toxicity assays.

PubMed

Allan, Hannah L; van de Merwe, Jason P; Finlayson, Kimberly A; O'Brien, Jake W; Mueller, Jochen F; Leusch, Frederic D L

2017-10-01

Agricultural processes are associated with many different herbicides that can contaminate surrounding environments. In Queensland, Australia, herbicides applied to agricultural crops may pose a threat to valuable coastal habitats including nesting beaches for threatened loggerhead turtles (Caretta caretta). This study 1) measured concentrations of herbicides in the beach sand of Mon Repos, an important marine turtle nesting beach in Australia that is adjacent to significant sugarcane crops, and 2) investigated the toxicity of these herbicides to marine turtles using a cell-based assay. Samples of sand from turtle nest depth and water from surrounding agricultural drains and wetlands were collected during the wet season when herbicide runoff was expected to be the greatest and turtles were nesting. Samples were extracted using solid phase extraction and extracts were analysed using chemical analysis targeting herbicides, as well as bioanalytical techniques (IPAM-assay and loggerhead turtle skin cell cytotoxicity assay). Twenty herbicides were detected in areas between sugarcane crops and the nesting beach, seven of which were also detected in the sand extracts. Herbicides present in the nearby wetland were also detected in the beach sand, indicating potential contamination of the nesting beach via the river outlet as well as ground water. Although herbicides were detected in nesting sand, bioassays using loggerhead turtle skin cells indicated a low risk of acute toxicity at measured environmental concentrations. Further research should investigate potentially more subtle effects, such as endocrine disruption and mixture effects, to better assess the threat that herbicides pose to this population of marine turtles. Copyright © 2017 Elsevier Ltd. All rights reserved.

KSC-2010-1350

NASA Image and Video Library

2010-01-19

CAPE CANAVERAL, Fla. - Brown pelicans sun themselves along the edges of the Turn Basin in Launch Complex 39 at NASA's Kennedy Space Center in Florida. Docked nearby is the Pegasus barge, often enlisted to bring the space shuttle's external tanks to the basin. The brown pelican is found along the coast in California and from North Carolina to Texas, Mexico, the West Indies and many Caribbean Islands, as well as Guyana and Venezuela in South America. It is listed as endangered only in Louisiana, Mississippi, and in the Caribbean. The species is considered to be long-lived. One pelican captured in Edgewater, Fla., in November 1964, was found to have been banded in September 1933, over 31 years previously. Individuals can weigh up to eight pounds, with larger pelicans having wing spreads of over seven feet. Their nests are usually built in mangrove trees, but ground nesting may also occur. Nesting takes place mostly in early spring or summer with the male carrying nesting materials to the female. Although the female builds the nest, both share in incubation and rearing duties. The Merritt Island National Wildlife Refuge coexists with Kennedy Space Center and provides a habitat for 330 species of birds including brown pelicans. Photo credit: NASA/Jack Pfaller

KSC-2010-1351

NASA Image and Video Library

2010-01-19

CAPE CANAVERAL, Fla. - Brown pelicans make unlikely companions for the Pegasus barge in the Turn Basin in Launch Complex 39 at NASA's Kennedy Space Center in Florida. The barge often transports the space shuttle's external tanks into the basin. The brown pelican is found along the coast in California and from North Carolina to Texas, Mexico, the West Indies and many Caribbean Islands, as well as Guyana and Venezuela in South America. It is listed as endangered only in Louisiana, Mississippi, and in the Caribbean. The species is considered to be long-lived. One pelican captured in Edgewater, Fla., in November 1964, was found to have been banded in September 1933, over 31 years previously. Individuals can weigh up to eight pounds, with larger pelicans having wing spreads of over seven feet. Their nests are usually built in mangrove trees, but ground nesting may also occur. Nesting takes place mostly in early spring or summer with the male carrying nesting materials to the female. Although the female builds the nest, both share in incubation and rearing duties. The Merritt Island National Wildlife Refuge coexists with Kennedy Space Center and provides a habitat for 330 species of birds including brown pelicans. Photo credit: NASA/Jack Pfaller

KSC-2010-1349

NASA Image and Video Library

2010-01-19

CAPE CANAVERAL, Fla. - A colony of brown pelicans enjoys a respite from the winter temperatures with a dip in the Turn Basin in Launch Complex 39 at NASA's Kennedy Space Center in Florida. The brown pelican is found along the coast in California and from North Carolina to Texas, Mexico, the West Indies and many Caribbean Islands, as well as Guyana and Venezuela in South America. It is listed as endangered only in Louisiana, Mississippi, and in the Caribbean. The species is considered to be long-lived. One pelican captured in Edgewater, Fla., in November 1964, was found to have been banded in September 1933, over 31 years previously. Individuals can weigh up to eight pounds, with larger pelicans having wing spreads of over seven feet. Their nests are usually built in mangrove trees, but ground nesting may also occur. Nesting takes place mostly in early spring or summer with the male carrying nesting materials to the female. Although the female builds the nest, both share in incubation and rearing duties. The Merritt Island National Wildlife Refuge coexists with Kennedy Space Center and provides a habitat for 330 species of birds including brown pelicans. Photo credit: NASA/Jack Pfaller

KSC-2010-1348

NASA Image and Video Library

2010-01-19

CAPE CANAVERAL, Fla. - A colony of brown pelicans takes advantage of a respite from winter temperatures to sun themselves along the edges of the Turn Basin in Launch Complex 39 at NASA's Kennedy Space Center in Florida. The brown pelican is found along the coast in California and from North Carolina to Texas, Mexico, the West Indies and many Caribbean Islands, as well as Guyana and Venezuela in South America. It is listed as endangered only in Louisiana, Mississippi, and in the Caribbean. The species is considered to be long-lived. One pelican captured in Edgewater, Fla., in November 1964, was found to have been banded in September 1933, over 31 years previously. Individuals can weigh up to eight pounds, with larger pelicans having wing spreads of over seven feet. Their nests are usually built in mangrove trees, but ground nesting may also occur. Nesting takes place mostly in early spring or summer with the male carrying nesting materials to the female. Although the female builds the nest, both share in incubation and rearing duties. The Merritt Island National Wildlife Refuge coexists with Kennedy Space Center and provides a habitat for 330 species of birds including brown pelicans. Photo credit: NASA/Jack Pfaller

Preliminary raptor surveys in western Mongolia

USGS Publications Warehouse

Ellis, D.H.; Ellis, Merlin H.; Tsengeg, Pu

1995-01-01

Raptors were observed on a 5200 km expedition from Ulaan Baatar through the Hangay Mountains to the Russian Altay Mountains with return through the Gobi Altay Mountains. The focus of the expedition was on nesting ecology of the Saker (Falco cherrug) and Altay falcons (F. altaicus) (25 eyries were located), but nests were also found for seven other species including more than 30 nests found of the upland buzzard (Buteo hemilasius). We conducted 21 day-long counts and 10 more formal raptor road counts. Raptors were concentrated in areas where perches were common and where food was most abundant. Western Mongolia remains a vast undeveloped land where camel trains and yak carts are normal. No developed highway network exists. Raptor work in the interior must be supported by four-wheel drive vehicles traveling cross country. Food and fuel for a research team are difficult to procure, but raptor populations are largely unexploited. Raptors frequently nest on the ground or on very low cliffs and tress, and often nest in close proximity of pairs of their own and other species. Several areas of special significance to raptors are discussed including the Taleen Ulaan (Red Steppe) areas of granite dells which we recommend for status as an international reserve.

Collective fluid mechanics of honeybee nest ventilation

NASA Astrophysics Data System (ADS)

Gravish, Nick; Combes, Stacey; Wood, Robert J.; Peters, Jacob

2014-11-01

Honeybees thermoregulate their brood in the warm summer months by collectively fanning their wings and creating air flow through the nest. During nest ventilation workers flap their wings in close proximity in which wings continuously operate in unsteady oncoming flows (i.e. the wake of neighboring worker bees) and near the ground. The fluid mechanics of this collective aerodynamic phenomena are unstudied and may play an important role in the physiology of colony life. We have performed field and laboratory observations of the nest ventilation wing kinematics and air flow generated by individuals and groups of honeybee workers. Inspired from these field observations we describe here a robotic model system to study collective flapping wing aerodynamics. We microfabricate arrays of 1.4 cm long flapping wings and observe the air flow generated by arrays of two or more fanning robotic wings. We vary phase, frequency, and separation distance among wings and find that net output flow is enhanced when wings operate at the appropriate phase-distance relationship to catch shed vortices from neighboring wings. These results suggest that by varying position within the fanning array honeybee workers may benefit from collective aerodynamic interactions during nest ventilation.

Edge, height and visibility effects on nest predation by birds and mammals in the Brazilian cerrado

NASA Astrophysics Data System (ADS)

Dodonov, Pavel; Paneczko, Ingrid Toledo; Telles, Marina

2017-08-01

Edge influence is one of the main impacts in fragmented landscapes; yet, most of studies on edge influence have focused on high-contrast edges, and the impacts of low-contrast edges and narrow linear openings are less understood. Edge influence often affects bird nest predation, but these effects are not ubiquitous and may depend on characteristics such as nest height and visibility. We performed an experiment on nest predation in a migratory passerine, Elaenia chiriquensis (Lesser Elaenia; Passeriformes: Tyrannidae), in a savanna vegetation of the Brazilian Cerrado biome in South-Eastern Brazil. We used 89 real E. chiriquensis nests, collected during previous reproductive seasons, with two plasticine eggs in each, and randomly distributed them at two locations (edge - up to 20 m from a firebreak edge and interior - approx. 150-350 m from the edge) and two heights (low - 60-175 cm and high - 190-315 cm above ground). We also measured leaf and branch density around each nest. We performed this study on two 15-days campaigns, checking the nests every 2-3 days and removing those with predation marks. We sorted the predation marks into those made by birds, mammals, or unidentified predators, and used generalized linear models to assess the effects of location, height and leaf density on survival time and predator type. Only four nests had not been predated during the experiment; 55 nests were predated by birds, 7 by mammals, and 23 by unidentified predators. Low nests in the interior tended to have larger survival times whereas high nests at the edge tended to be more predated by birds and less predated by mammals. Thus, even a low-contrast (firebreak) edge may significantly increase nest predation, which is also affected by the nest's height, mainly due to predation by birds. These effects may be due to predator movement along the edge as well as to edge-related changes in vegetation structure. We suggest that higher-contrast edges which may also be used as movement conduits, for example powerline openings, may have even stronger effects, demanding further studies.

Nest trampling and ground nesting birds: Quantifying temporal and spatial overlap between cattle activity and breeding redshank.

PubMed

Sharps, Elwyn; Smart, Jennifer; Mason, Lucy R; Jones, Kate; Skov, Martin W; Garbutt, Angus; Hiddink, Jan G

2017-08-01

Conservation grazing for breeding birds needs to balance the positive effects on vegetation structure and negative effects of nest trampling. In the UK, populations of Common redshank Tringa totanus breeding on saltmarshes declined by >50% between 1985 and 2011. These declines have been linked to changes in grazing management. The highest breeding densities of redshank on saltmarshes are found in lightly grazed areas. Conservation initiatives have encouraged low-intensity grazing at <1 cattle/ha, but even these levels of grazing can result in high levels of nest trampling. If livestock distribution is not spatially or temporally homogenous but concentrated where and when redshank breed, rates of nest trampling may be much higher than expected based on livestock density alone. By GPS tracking cattle on saltmarshes and monitoring trampling of dummy nests, this study quantified (i) the spatial and temporal distribution of cattle in relation to the distribution of redshank nesting habitats and (ii) trampling rates of dummy nests. The distribution of livestock was highly variable depending on both time in the season and the saltmarsh under study, with cattle using between 3% and 42% of the saltmarsh extent and spending most their time on higher elevation habitat within 500 m of the sea wall, but moving further onto the saltmarsh as the season progressed. Breeding redshank also nest on these higher elevation zones, and this breeding coincides with the early period of grazing. Probability of nest trampling was correlated to livestock density and was up to six times higher in the areas where redshank breed. This overlap in both space and time of the habitat use of cattle and redshank means that the trampling probability of a nest can be much higher than would be expected based on standard measures of cattle density. Synthesis and applications : Because saltmarsh grazing is required to maintain a favorable vegetation structure for redshank breeding, grazing management should aim to keep livestock away from redshank nesting habitat between mid-April and mid-July when nests are active, through delaying the onset of grazing or introducing a rotational grazing system.

Natal foraging philopatry in eastern Pacific hawksbill turtles.

PubMed

Gaos, Alexander R; Lewison, Rebecca L; Jensen, Michael P; Liles, Michael J; Henriquez, Ana; Chavarria, Sofia; Pacheco, Carlos Mario; Valle, Melissa; Melero, David; Gadea, Velkiss; Altamirano, Eduardo; Torres, Perla; Vallejo, Felipe; Miranda, Cristina; LeMarie, Carolina; Lucero, Jesus; Oceguera, Karen; Chácon, Didiher; Fonseca, Luis; Abrego, Marino; Seminoff, Jeffrey A; Flores, Eric E; Llamas, Israel; Donadi, Rodrigo; Peña, Bernardo; Muñoz, Juan Pablo; Ruales, Daniela Alarcòn; Chaves, Jaime A; Otterstrom, Sarah; Zavala, Alan; Hart, Catherine E; Brittain, Rachel; Alfaro-Shigueto, Joanna; Mangel, Jeffrey; Yañez, Ingrid L; Dutton, Peter H

2017-08-01

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles ( Eretmochelys imbricata ) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.

Natal foraging philopatry in eastern Pacific hawksbill turtles

PubMed Central

Lewison, Rebecca L.; Jensen, Michael P.; Liles, Michael J.; Henriquez, Ana; Chavarria, Sofia; Pacheco, Carlos Mario; Valle, Melissa; Melero, David; Gadea, Velkiss; Altamirano, Eduardo; Torres, Perla; Vallejo, Felipe; Miranda, Cristina; LeMarie, Carolina; Lucero, Jesus; Oceguera, Karen; Chácon, Didiher; Fonseca, Luis; Abrego, Marino; Seminoff, Jeffrey A.; Flores, Eric E.; Llamas, Israel; Donadi, Rodrigo; Peña, Bernardo; Muñoz, Juan Pablo; Ruales, Daniela Alarcòn; Chaves, Jaime A.; Otterstrom, Sarah; Zavala, Alan; Hart, Catherine E.; Brittain, Rachel; Alfaro-Shigueto, Joanna; Mangel, Jeffrey; Yañez, Ingrid L.; Dutton, Peter H.

2017-01-01

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles (Eretmochelys imbricata) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry. PMID:28878969

Toroidal converter core

NASA Technical Reports Server (NTRS)

Mclyman, W. T.

1977-01-01

Improved approach consists of cut and uncut cores nested in concentric configuration. Cores are made by winding steel ribbon on mandrel and impregnating with epoxy to bond layers together. Gap is made by cutting across wound and bonded core. Rough ends are ground or lapped.

Seasonal infestation of birds with immature stages of Ixodes ricinus and Ixodes arboricola.

PubMed

Kocianová, Elena; Rusňáková Tarageľová, Veronika; Haruštiaková, Danka; Špitalská, Eva

2017-03-01

This study assessed the parasitization of cavity-nesting birds and ground-nesting/foraging birds with larvae and nymphs of two Ixodes species, Ixodes ricinus and Ixodes arboricola. Totals of 679 (52.3%) I. ricinus and 619 (47.7%) I. arboricola ticks were collected from 15 species of passerine birds which were caught during the nesting and non-nesting periods of 2003-2006, in the south-eastern part of the Czech Republic, the Drahanská Vrchovina Uplands. In the non-nesting period from October to March, 6.8% (101/1492) of birds were infested with ticks, mainly with I. arboricola larvae. In the non-nesting period, the average intensity of infestation by I. arboricola and I. ricinus was 8.5 and 1.5 individuals per infested bird, respectively. In the nesting period from April to June, 21.6% (50/232) of birds were infested by both tick species but mainly with I. ricinus nymphs. The average intensity of infestation by I. ricinus and I. arboricola was 13.3 and 10.8 individuals per infested bird, respectively. Altogether, 23.2% of the infested birds were parasitized by both immature life stages of one or both tick species. From an enzootic perspective, co-feeding and co-infestation of I. ricinus and I. arboricola subadults on passerine birds might happen and may be important for the dissemination of tick-borne agents. Copyright © 2017 Elsevier GmbH. All rights reserved.

Managing native predators: Evidence from a partial removal of raccoons (Procyon lotor) on the Outer Banks of North Carolina, USA

USGS Publications Warehouse

Stocking, Jessica J.; Simons, Theodore R.; Parsons, Arielle W.; O'Connell, Allan F.

2017-01-01

Raccoons (Procyon lotor) are important predators of ground-nesting species in coastal systems. They have been identified as a primary cause of nest failure for the American Oystercatcher (Haematopus palliatus) throughout its range. Concerns over the long-term effects of raccoon predation and increased nest success following a hurricane inspired a mark-resight study of the raccoon population on a barrier island off North Carolina, USA. Approximately half of the raccoons were experimentally removed in 2008. Nests (n = 700) were monitored on two adjacent barrier islands during 2004–2013. Daily nest survival estimates were highest for 2004 (0.974 ± 0.005) and lowest for 2007 and 2008 (0.925 ± 0.009 and 0.925 ± 0.010, respectively). The only model in our candidate set that received any support included island and time of season, along with a diminishing effect of the hurricane and a constant, 5-year effect of the raccoon removal. For both hurricane and raccoon removal, however, the support for island-specific effects was weak (β = -0.204 ± 0.116 and 0.146 ± 0.349, respectively). We conclude that either the raccoon reduction was inadequate, or factors other than predation cause more variation in nest success than previously recognized. A multi-faceted approach to management aimed at reducing nest losses to storm overwash, predation, and human disturbance is likely to yield the largest population level benefits.

Effects of Supplementary Feeding on the Breeding Ecology of the Buff-Throated Partridge in a Tibetan Sacred Site, China.

PubMed

Yang, Nan; Moermond, Timothy C; Lloyd, Huw; Xu, Yu; Dou, Liang; Zhang, Kai; Yue, Bisong; Ran, Jianghong

2016-01-01

Our goal was to document effects of year-round supplemental feeding on breeding ecology of the Buff-throated Partridge, Tetraophasis szechenyii, within a Tibetan sacred site. We evaluated effects of supplemental feeding used as religious/cultural practices which could potentially aid conservation of endangered phasianids. We compared fed breeding groups to neighboring nonfed groups. Fed groups initiated first clutches significantly earlier than nonfed groups. Earlier laying groups within fed and nonfed groups showed significantly lower hatching rates than later groups; however, fed groups showed significantly higher hatching rates than nonfed groups laying in the same period. Earlier laying increased opportunities to renest. All six fed groups with clutch failures renested compared to only one of five nonfed groups with clutch failures. Fed female breeders showed significantly greater investment in their young with larger clutches and larger eggs, which likely increased survivability of early hatchlings. We observed no predation on birds at feeding sites and recorded only four cases of predation on incubating females, which showed no detectable difference between fed and nonfed groups. Ground-nesting birds typically face high risks of predation. Ten of the 48 groups nested in trees, which occurs in few phasianid species. Tree nests showed significantly higher hatching rates compared to ground nests; however, we found no significant difference in tree nesting between fed and nonfed groups. This partridge is one of four gallinaceous species with cooperative breeding. Breeding groups with helpers had significantly greater reproductive success than single pairs, and fed female breeders with helpers laid bigger eggs than single pairs. Comparing annual reproductive output per group, fed groups not only produced significantly more independent young (≥ 150 days post-hatching), their young hatched significantly earlier, which likely have greater reproductive value over later hatched young of nonfed groups. Supplemental feeding year-round is likely what enabled the successes of the fed partridges.

Unusual sleeping site selection by southern bamboo lemurs.

PubMed

Eppley, Timothy M; Donati, Giuseppe; Ganzhorn, Jörg U

2016-04-01

Selection of sleeping sites has consequences for individual fitness. Non-human primates often bias their selection towards arboreal sites, and the lemurs of Madagascar typically rest/sleep in trees, tree holes, and/or constructed nests. Three non-mutually exclusive hypotheses to explain sleeping site selection include protection from predators, avoidance of parasitic vectors, and improved thermoregulation. Here, we examine these hypotheses for the unusual sleeping site selections by the southern bamboo lemur (Hapalemur meridionalis). Within the Mandena littoral forest of southeast Madagascar, the southern bamboo lemur is known for its ecological flexibility compared to other bamboo lemur species, including a dietary niche expansion to feeding on the ground. Between October 2012 and December 2013, we observed bamboo lemurs from three social groups for 1778.67 h, conducting full-day focal follows on 11 adult individuals (five males, six females). During this period, all three groups were observed to sleep on the ground, with one of these groups also using an abandoned nest of a Madagascar crested ibis (Lophotibis cristata). We collected habitat and temperature data to examine whether selection was influenced by environmental variables. Terrestrial sleeping (N = 17) was observed in all individuals but one adult female, with individuals burrowing under thick vegetation more often during the hot austral summer. While difficult to rigorously test, it is possible that terrestrial sleep sites and/or sleeping in a bird nest may impair visual detection by some aerial and terrestrial predators. Neither of these sites (i.e., terrestrial sleeping or use of a bird nest), however, is likely to minimize exposure to parasites/vectors. Terrestrial sleeping appears to support a thermoregulatory strategy, whereas the use of a bird nest could not be empirically tested. Our observations of unique sleeping site locations used by southern bamboo lemurs further the complexity of their natural history and that of Malagasy strepsirrhines.

The causes of dispersal and the cost of carry-over effects for an endangered bird in a dynamic wetland landscape.

PubMed

Robertson, Ellen P; Fletcher, Robert J; Austin, James D

2017-07-01

The decision to disperse or remain philopatric between breeding seasons has important implications for both ecology and evolution, including the potential for carry-over effects, where an individual's previous history affects its current performance. Carry-over effects are increasingly documented although underlying mechanisms remain unclear. Here we test for potential carry-over effects and their mechanisms by uniting hypotheses for the causes and consequences of habitat selection and dispersal across space and time. We linked hypotheses regarding different types of factors and information (environmental conditions, personal and public information) predicted to impact reproductive success and dispersal for an endangered, wetland-dependent bird, the snail kite (Rostrhamus sociabilis plumbeus). To do so, we coupled structural equation modelling with 20 years of mark-recapture and nesting data across the breeding range of this species to isolate potential direct and indirect effects of these factors. We found that water depth at nest sites explained subsequent emigration rates via an indirect path through the use of personal, not public, information. Importantly, we found that these dispersers tended to initiate nests later the following breeding season. This pattern explained a phenological mismatch of nesting with hydrological conditions, whereby immigrants tended to nest later, late nesters tended to experience lower water depths, higher nest failure occurred at lower water depths and higher nest failure explained subsequent breeding dispersal. These results identified a novel potential mechanism for carry-over effects: a phenological mismatch with environmental conditions (water depth) that occurred potentially due to time costs of dispersal. Our results also highlighted a substantial benefit of philopatry - earlier initiation of reproduction - which allows philopatric individuals to better coincide with environmental conditions that are beneficial for successful reproduction. These results have implications for our mechanistic understanding and prediction of carryover effects, and emphasize that local conservation strategies, such as water management, can explain future demography at distant sites connected through dispersal. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

KSC-2009-1512

NASA Image and Video Library

2009-01-31

CAPE CANAVERAL, Fla. – A pair of ospreys perform an aerial dance around their nest near the NASA News Center at NASA's Kennedy Space Center in Florida. The bird at right is carrying a fish in its talons, the sole source of its diet. The osprey, also called fish hawk, is well adapted for capturing fish, which make up its entire diet. The soles of the birds' feet are equipped with sharp, spiny projections that give the bird a firm grip on its slippery prey. Nests of ospreys are bulky masses of sticks and debris placed in a tree, on rocks, flat ground or telephone poles. Many nests exist around the Launch Complex 39 Area at the center. The bird is one of more than 500 species of birds that co-exist at the center and the surrounding Merritt Island National Wildlife Refuge. Photo credit: NASA/Ben Smelgelsky

KSC-06pd0688

NASA Image and Video Library

2006-04-20

KENNEDY SPACE CENTER, FLA. -- A mother osprey watches over her chicks in a nest near the NASA News Center at Kennedy Space Center. This is the third year the ospreys have raised a family at the site. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge, which shares a boundary with the Center. Photo credit: NASA/George Shelton

Installation Restoration Program Records Search for Mountain Home Air Force Base, Idaho.

DTIC Science & Technology

1983-07-01

ornamental plantings. Mammals found on and around the base include coyote, black-tailed jackrabbit, cottontail, Franklin’s ground squirrel, and yellow - bellied ...Water Well Location Map. ::HILLI L - -- - • Depthin Feet Natural Ground Level Top Soil & Yellow Clay Subsoil Grey Basalt Rock-Medium Hardi30" Casing Grey... marmot as well as several varieties of small rodents. Birds which commonly nest on the base include American robin, house finch, English sparrow

Ecological consequences of mountain pine beetle outbreaks for wildlife in western North American forests

USGS Publications Warehouse

Saab, Victoria A.; Latif, Quresh S.; Rowland, Mary M.; Johnson, Tracey N.; Chalfoun, Anna D.; Buskirk, Steven W.; Heyward, Joslin E.; Dresser, Matthew A.

2014-01-01

Mountain pine beetle (Dendroctonus ponderosae) (MPB) outbreaks are increasingly prevalent in western North America, causing considerable ecological change in pine (Pinus spp.) forests with important implications for wildlife. We reviewed studies examining wildlife responses to MPB outbreaks and postoutbreak salvage logging to inform forest management and guide future research. Our review included 16 studies describing MPB outbreak relationships with 89 bird species and 6 studies describing relationships with 11 mammalian species, but no studies of reptiles or amphibians. We included studies that compared wildlife response metrics temporally (before versus after the outbreak) and spatially (across sites that varied in severity of outbreak) in relation to beetle outbreaks. Outbreaks ranged in size from 20,600 to ≥107 ha and studies occurred 1‐30 years after the peak MPB outbreak, but most studies were conducted over the short-term (i.e., ≤6 years after the peak of MPB-induced tree mortality). Birds were the only taxa studied frequently; however, high variability existed among those studies to allow many inferences, although some patterns were evident. Avian studies concluded that cavity-nesting species responded more favorably to beetle-killed forests than species with open-cup nests, and species nesting in the shrub layer favored outbreak forests compared with ground and open-cup canopy nesters that generally showed mixed relationships. Bark-drilling species as a group clearly demonstrated a positive short-term association with MPB epidemics compared with that of other foraging assemblages. Cavity-nesting birds that do not consume bark beetles (i.e., secondary cavity-nesting species and nonbark-drilling woodpeckers) also exhibited some positive responses to MPB outbreaks, although not as pronounced or consistent as those of bark-drilling woodpeckers. Mammalian responses to MPB outbreaks were mixed. Studies consistently reported negative effects of MPB outbreaks on red squirrels (Tamiasciurus hudsonicus). However, there is evidence that red squirrels can persist after an outbreak under some conditions, e.g., when nonhost tree species are present. For small mammal species associated with forest understories, responses may be most pronounced during the postepidemic period (>6 years after the peak of beetle-induced tree mortality) when snags fall to produce coarse woody debris. Postoutbreak salvage logging studies (n = 6) reported results that lacked consensus. Postoutbreak salvage logging may have an impact on fewer wildlife species than postfire salvage logging, probably because only host-specific tree species are removed after beetle outbreaks.

Landscapes for Energy and Wildlife: Conservation Prioritization for Golden Eagles across Large Spatial Scales

PubMed Central

Tack, Jason D.; Fedy, Bradley C.

2015-01-01

Proactive conservation planning for species requires the identification of important spatial attributes across ecologically relevant scales in a model-based framework. However, it is often difficult to develop predictive models, as the explanatory data required for model development across regional management scales is rarely available. Golden eagles are a large-ranging predator of conservation concern in the United States that may be negatively affected by wind energy development. Thus, identifying landscapes least likely to pose conflict between eagles and wind development via shared space prior to development will be critical for conserving populations in the face of imposing development. We used publically available data on golden eagle nests to generate predictive models of golden eagle nesting sites in Wyoming, USA, using a suite of environmental and anthropogenic variables. By overlaying predictive models of golden eagle nesting habitat with wind energy resource maps, we highlight areas of potential conflict among eagle nesting habitat and wind development. However, our results suggest that wind potential and the relative probability of golden eagle nesting are not necessarily spatially correlated. Indeed, the majority of our sample frame includes areas with disparate predictions between suitable nesting habitat and potential for developing wind energy resources. Map predictions cannot replace on-the-ground monitoring for potential risk of wind turbines on wildlife populations, though they provide industry and managers a useful framework to first assess potential development. PMID:26262876

Landscapes for energy and wildlife: conservation prioritization for golden eagles across large spatial scales

USGS Publications Warehouse

Tack, Jason D.; Fedy, Bradley C.

2015-01-01

Proactive conservation planning for species requires the identification of important spatial attributes across ecologically relevant scales in a model-based framework. However, it is often difficult to develop predictive models, as the explanatory data required for model development across regional management scales is rarely available. Golden eagles are a large-ranging predator of conservation concern in the United States that may be negatively affected by wind energy development. Thus, identifying landscapes least likely to pose conflict between eagles and wind development via shared space prior to development will be critical for conserving populations in the face of imposing development. We used publically available data on golden eagle nests to generate predictive models of golden eagle nesting sites in Wyoming, USA, using a suite of environmental and anthropogenic variables. By overlaying predictive models of golden eagle nesting habitat with wind energy resource maps, we highlight areas of potential conflict among eagle nesting habitat and wind development. However, our results suggest that wind potential and the relative probability of golden eagle nesting are not necessarily spatially correlated. Indeed, the majority of our sample frame includes areas with disparate predictions between suitable nesting habitat and potential for developing wind energy resources. Map predictions cannot replace on-the-ground monitoring for potential risk of wind turbines on wildlife populations, though they provide industry and managers a useful framework to first assess potential development.

Landscapes for Energy and Wildlife: Conservation Prioritization for Golden Eagles across Large Spatial Scales.

PubMed

Tack, Jason D; Fedy, Bradley C

2015-01-01

Proactive conservation planning for species requires the identification of important spatial attributes across ecologically relevant scales in a model-based framework. However, it is often difficult to develop predictive models, as the explanatory data required for model development across regional management scales is rarely available. Golden eagles are a large-ranging predator of conservation concern in the United States that may be negatively affected by wind energy development. Thus, identifying landscapes least likely to pose conflict between eagles and wind development via shared space prior to development will be critical for conserving populations in the face of imposing development. We used publically available data on golden eagle nests to generate predictive models of golden eagle nesting sites in Wyoming, USA, using a suite of environmental and anthropogenic variables. By overlaying predictive models of golden eagle nesting habitat with wind energy resource maps, we highlight areas of potential conflict among eagle nesting habitat and wind development. However, our results suggest that wind potential and the relative probability of golden eagle nesting are not necessarily spatially correlated. Indeed, the majority of our sample frame includes areas with disparate predictions between suitable nesting habitat and potential for developing wind energy resources. Map predictions cannot replace on-the-ground monitoring for potential risk of wind turbines on wildlife populations, though they provide industry and managers a useful framework to first assess potential development.

Microhabitat Conditions in Wyoming's Sage-Grouse Core Areas: Effects on Nest Site Selection and Success.

PubMed

Dinkins, Jonathan B; Smith, Kurt T; Beck, Jeffrey L; Kirol, Christopher P; Pratt, Aaron C; Conover, Michael R

2016-01-01

The purpose of our study was to identify microhabitat characteristics of greater sage-grouse (Centrocercus urophasianus) nest site selection and survival to determine the quality of sage-grouse habitat in 5 regions of central and southwest Wyoming associated with Wyoming's Core Area Policy. Wyoming's Core Area Policy was enacted in 2008 to reduce human disturbance near the greatest densities of sage-grouse. Our analyses aimed to assess sage-grouse nest selection and success at multiple micro-spatial scales. We obtained microhabitat data from 928 sage-grouse nest locations and 819 random microhabitat locations from 2008-2014. Nest success was estimated from 924 nests with survival data. Sage-grouse selected nests with greater sagebrush cover and height, visual obstruction, and number of small gaps between shrubs (gap size ≥0.5 m and <1.0 m), while selecting for less bare ground and rock. With the exception of more small gaps between shrubs, we did not find any differences in availability of these microhabitat characteristics between locations within and outside of Core Areas. In addition, we found little supporting evidence that sage-grouse were selecting different nest sites in Core Areas relative to areas outside of Core. The Kaplan-Meier nest success estimate for a 27-day incubation period was 42.0% (95% CI: 38.4-45.9%). Risk of nest failure was negatively associated with greater rock and more medium-sized gaps between shrubs (gap size ≥2.0 m and <3.0 m). Within our study areas, Wyoming's Core Areas did not have differing microhabitat quality compared to outside of Core Areas. The close proximity of our locations within and outside of Core Areas likely explained our lack of finding differences in microhabitat quality among locations within these landscapes. However, the Core Area Policy is most likely to conserve high quality habitat at larger spatial scales, which over decades may have cascading effects on microhabitat quality available between areas within and outside of Core Areas.

Impacts of Water Levels on Breeding Canada Geese and Methods for Mitigation and Management in the Southern Flathead Valley, Montana, 1983-1987 Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mackey, Dennis L.; Gregory, Shari K.; Matthews, William C. Jr.

Kerr Hydroelectric Dam is located at the south end of Flathead Lake, controls water levels on the lake and the Flathead River below the dam, and is currently operated as a load control facility. Current operation of Kerr Dam creates the greatest yearly water level fluctuations on both the lake and river during the Canada goose (Branta canadensis moffitti) brood and nesting period. Data collected from 1980-1982 indicated that goose nest numbers on the river were lower than during the 1950's, and that brood habitat on the lake may be limiting the goose population there. Our study was conducted frommore » 1983-1987 to determine the effects of Kerr Dam operation on Canada goose populations and habitat on the south half of Flathead Lake and the Flathead River, and to formulate management and mitigation recommendations. Nesting geese on the river appeared to be negatively affected by a lack of nest sites free from predators, and responded to available artificial nest structures with an increase in nest numbers and nesting success. Under current dam operation, river channel depths and widths do not discourage access to nesting islands by mammalian predators during some years and high predation on ground nests occurs. Intensively used brood areas on the lake and river were identified and described. Brood habitat on the lake was lower in quality and quantity than on the river due to dam operations. Gosling mortality on the lake was high, almost 2 times higher than on the river. Lake broods expended more energy obtaining food than river broods. Losses of brood habitat in the form of wet meadow marshes were documented and mitigation options developed. Management/mitigation alternatives and monitoring methods for nesting and brooding geese were identified.« less

Disentangling endogenous versus exogenous pattern formation in spatial ecology: a case study of the ant Azteca sericeasur in southern Mexico.

PubMed

Li, Kevin; Vandermeer, John H; Perfecto, Ivette

2016-05-01

Spatial patterns in ecology can be described as reflective of environmental heterogeneity (exogenous), or emergent from dynamic relationships between interacting species (endogenous), but few empirical studies focus on the combination. The spatial distribution of the nests of Azteca sericeasur, a keystone tropical arboreal ant, is thought to form endogenous spatial patterns among the shade trees of a coffee plantation through self-regulating interactions with controlling agents (i.e. natural enemies). Using inhomogeneous point process models, we found evidence for both types of processes in the spatial distribution of A. sericeasur. Each year's nest distribution was determined mainly by a density-dependent relationship with the previous year's lagged nest density; but using a novel application of a Thomas cluster process to account for the effects of nest clustering, we found that nest distribution also correlated significantly with tree density in the later years of the study. This coincided with the initiation of agricultural intensification and tree felling on the coffee farm. The emergence of this significant exogenous effect, along with the changing character of the density-dependent effect of lagged nest density, provides clues to the mechanism behind a unique phenomenon observed in the plot, that of an increase in nest population despite resource limitation in nest sites. Our results have implications in coffee agroecological management, as this system provides important biocontrol ecosystem services. Further research is needed, however, to understand the effective scales at which these relationships occur.

[Reservation forms of plague infectious agent in Tuva natural focus].

PubMed

Bazanova, L P; Innokent'eva, T I

2012-01-01

Data characterizing the reservation forms of plague infectious agent in Tuva natural focus are presented in the review. Yersinia pestis was shown to persist most of the year in Citellophilus tesquorum altaicus imago --the main carrier, getting into the animal organism only for a short time. An increased ability to aggregate in autumn and accumulate in clumps of C. tesquorum altaicus females that are more adapted to survive the cold season compared with males promote the persistence of the microorganism. The plague infectious agent in the altered form survives in the organism of females not only the winter period but also longer periods of time that is demonstrated by the facts of detection of it after 646 days of staying in the carrier. Moreover Yersinia pestis can persist for more than 400 days in the substrate of the nest of long-tailed ground squirrel infected by excrements and corpses of plague fleas. The substrate of the nest infected in summer-autumn period of the previous year may determine the primary infection of ground squirrels by plague infectious agent in the next epizootic season. On ground squirrels infected during contact with nest substrate, infection of intact fleas may be possible, and so the initiation of a new cycle of transmission of the infectious agent. Adaptation of the plague infectious agent to unfavorable existence conditions in the carrier is expressed in the changes of its morphology and ultrastructure that is evidenced by the facts of isolation of the infectious agent from corpses of fleas situated in the substrate, in the L-form, as well as results of phase-contrast and electron microscopy of the digestive tract of C. tesquorum altaicus.

[Nesting habitat characterization for Amazona oratrix (Psittaciformes: Psittacidae) in the Central Pacific, Mexico].

PubMed

Monterrubio-Rico, Tiberio C; Álvarez-Jara, Margarito; Tellez-Garcia, Loreno; Tena-Morelos, Carlos

2014-09-01

The nesting requirements of the Yellow-headed Parrot (Amazona oratrix) are poorly understood, despite their broad historical distribution, high demand for pet trade and current endangered status. Information concerning their nesting requirements is required in order to design specific restoration and conser- vation actions. To assess this, we studied their nesting ecology in the Central Pacific, Michoacan, Mexico during a ten year period. The analyzed variables ranged from local scale nest site characteristics such as nesting tree species, dimensions, geographic positions, diet and nesting forest patches structure, to large scale features such as vegetation use and climatic variables associated to the nesting tree distributions by an ecological niche model using Maxent. We also evaluated the parrot tolerance to land management regimes, and compared the Pacific nest trees with 18 nest trees recorded in an intensively managed private ranch in Tamaulipas, Gulf of Mexico. Parrots nested in tall trees with canopy level cavities in 92 nest-trees recorded from 11 tree species. The 72.8% of nesting occurred in trees of Astronium graveolens, and Enterolobium cyclocarpum which qualified as key- stone trees. The forests where the parrots nested, presented a maximum of 54 tree species, 50% of which were identified as food source; besides, these areas also had a high abundance of trees used as food supply. The lowest number of tree species and trees to forage occurred in an active cattle ranch, whereas the highest species rich- ness was observed in areas with natural recovery. The nesting cavity entrance height from above ground of the Pacific nesting trees resulted higher than those found in the Gulf of Mexico. We hypothesize that the differences may be attributed to Parrot behavioral differences adapting to differential poaching pressure and cavity avail- ability. Nesting trees were found in six vegetation types; however the parrots preferred conserved and riparian semi-deciduous forest for nesting, with fewer nests in deciduous forest, while nesting in transformed agricultural fields was avoided. The main climatic variables associated with the potential distribution of nests were: mean temperature of wettest quarter, mean diurnal temperature range, and precipitation of wettest month. Suitable cli- matic conditions for the potential presence of nesting trees were present in 61% of the region; however, most of the area consisted of tropical deciduous forests (55.8%), while semi-deciduous tropical forests covered only 17% of the region. These results indicated the importance to conserve semi-deciduous forests as breeding habitats for the Yellow-headed Parrot, and revealed the urgent need to implement conservation and restoration actions. These should include a total ban of land use change in tropical semi-deciduous forest areas, and for selective logging of all keystone tree species; besides, we recommend the establishment of wildlife sanctuaries in important nesting areas, and a series of tropical forest restoration programs in the Central Pacific coast.

Assessing species habitat using Google Street View: a case study of cliff-nesting vultures.

PubMed

Olea, Pedro P; Mateo-Tomás, Patricia

2013-01-01

The assessment of a species' habitat is a crucial issue in ecology and conservation. While the collection of habitat data has been boosted by the availability of remote sensing technologies, certain habitat types have yet to be collected through costly, on-ground surveys, limiting study over large areas. Cliffs are ecosystems that provide habitat for a rich biodiversity, especially raptors. Because of their principally vertical structure, however, cliffs are not easy to study by remote sensing technologies, posing a challenge for many researches and managers working with cliff-related biodiversity. We explore the feasibility of Google Street View, a freely available on-line tool, to remotely identify and assess the nesting habitat of two cliff-nesting vultures (the griffon vulture and the globally endangered Egyptian vulture) in northwestern Spain. Two main usefulness of Google Street View to ecologists and conservation biologists were evaluated: i) remotely identifying a species' potential habitat and ii) extracting fine-scale habitat information. Google Street View imagery covered 49% (1,907 km) of the roads of our study area (7,000 km²). The potential visibility covered by on-ground surveys was significantly greater (mean: 97.4%) than that of Google Street View (48.1%). However, incorporating Google Street View to the vulture's habitat survey would save, on average, 36% in time and 49.5% in funds with respect to the on-ground survey only. The ability of Google Street View to identify cliffs (overall accuracy = 100%) outperformed the classification maps derived from digital elevation models (DEMs) (62-95%). Nonetheless, high-performance DEM maps may be useful to compensate Google Street View coverage limitations. Through Google Street View we could examine 66% of the vultures' nesting-cliffs existing in the study area (n = 148): 64% from griffon vultures and 65% from Egyptian vultures. It also allowed us the extraction of fine-scale features of cliffs. This World Wide Web-based methodology may be a useful, complementary tool to remotely map and assess the potential habitat of cliff-dependent biodiversity over large geographic areas, saving survey-related costs.

Assessing Species Habitat Using Google Street View: A Case Study of Cliff-Nesting Vultures

PubMed Central

Olea, Pedro P.; Mateo-Tomás, Patricia

2013-01-01

The assessment of a species’ habitat is a crucial issue in ecology and conservation. While the collection of habitat data has been boosted by the availability of remote sensing technologies, certain habitat types have yet to be collected through costly, on-ground surveys, limiting study over large areas. Cliffs are ecosystems that provide habitat for a rich biodiversity, especially raptors. Because of their principally vertical structure, however, cliffs are not easy to study by remote sensing technologies, posing a challenge for many researches and managers working with cliff-related biodiversity. We explore the feasibility of Google Street View, a freely available on-line tool, to remotely identify and assess the nesting habitat of two cliff-nesting vultures (the griffon vulture and the globally endangered Egyptian vulture) in northwestern Spain. Two main usefulness of Google Street View to ecologists and conservation biologists were evaluated: i) remotely identifying a species’ potential habitat and ii) extracting fine-scale habitat information. Google Street View imagery covered 49% (1,907 km) of the roads of our study area (7,000 km2). The potential visibility covered by on-ground surveys was significantly greater (mean: 97.4%) than that of Google Street View (48.1%). However, incorporating Google Street View to the vulture’s habitat survey would save, on average, 36% in time and 49.5% in funds with respect to the on-ground survey only. The ability of Google Street View to identify cliffs (overall accuracy = 100%) outperformed the classification maps derived from digital elevation models (DEMs) (62–95%). Nonetheless, high-performance DEM maps may be useful to compensate Google Street View coverage limitations. Through Google Street View we could examine 66% of the vultures’ nesting-cliffs existing in the study area (n = 148): 64% from griffon vultures and 65% from Egyptian vultures. It also allowed us the extraction of fine-scale features of cliffs. This World Wide Web-based methodology may be a useful, complementary tool to remotely map and assess the potential habitat of cliff-dependent biodiversity over large geographic areas, saving survey-related costs. PMID:23355880

Uruguay Roselli 1938 and Rosellichnus, N. Ichnogenus: Two ichnogenera for clusters of fossil bee cells

USGS Publications Warehouse

Genise, Jorge F.; Bown, Thomas M.

1996-01-01

The systematics of the fossil bee nest ichnogenus Uruguay from the Uruguayan Cretaceous or lower Tertiary is reviewed and two new ichnospecies of a new ichnogenus, Rosellichnus, are proposed for fossil bee nests from the Miocene of the United Arab Emirates and Patagonian Argentina. Uruguay contains U. auroranormae(the ich‐notype) and U. rivasi, which differs from the type ichnospecies in having clustered cells arranged in three rows, with one central and two marginal rows of subparallel cells. No bee nest architecture known to us unequivocally fits with any ichnospecies described herein. Uruguay was constructed in the subsoil and may be of halictid origin; however, its large cell size, thick cell walls, and the presence of a vestibular cell do not fit the architecture of nests of extant halictids. Rosellichnus arabicus lacks the complete cavity surrounding the cell cluster that is typical in nests of Old World halictids, but it may, nonetheless, still be of halictid origin. R. pa‐tagonicus has an architecture more similar to nests of anthophorine bees than to those of Neotropical Halictidae. Therefore, the ichnogenus Rosellichnus may include both halictid and anthophorine constructions. Although the smooth inner cell walls, spiral cell caps, and clustering of cells indicate that both Uruguay and Rosellichnus are trace fossils of bee origin, it is likely that both represent nest architectures that are no longer employed by extant bees, or those that are as yet unknown. The paleoenvironments of both the Argentine and Emirates species of Rosellichnus indicate that the trace‐makers of this ichnogenus constructed their nests in open ground sandy soils.

Global Distribution of Two Fungal Pathogens Threatening Endangered Sea Turtles

PubMed Central

Sarmiento-Ramírez, Jullie M.; Abella-Pérez, Elena; Phillott, Andrea D.; Sim, Jolene; van West, Pieter; Martín, María P.; Marco, Adolfo; Diéguez-Uribeondo, Javier

2014-01-01

Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are implicated in low hatch success. These two fungi possess key biological features that are similar to emerging pathogens leading to host extinction, e.g., high virulence, and a broad host range style of life. Their optimal growth temperature overlap with the optimal incubation temperature for eggs, and they are able to kill up to 90% of the embryos. Environmental forcing, e.g., tidal inundation and clay/silt content of nests, were correlated to disease development. Thus, these Fusarium species constitute a major threat to sea turtle nests, especially to those experiencing environmental stressors. These findings have serious implications for the survival of endangered sea turtle populations and the success of conservation programs worldwide. PMID:24465748

Global distribution of two fungal pathogens threatening endangered sea turtles.

PubMed

Sarmiento-Ramírez, Jullie M; Abella-Pérez, Elena; Phillott, Andrea D; Sim, Jolene; van West, Pieter; Martín, María P; Marco, Adolfo; Diéguez-Uribeondo, Javier

2014-01-01

Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are implicated in low hatch success. These two fungi possess key biological features that are similar to emerging pathogens leading to host extinction, e.g., high virulence, and a broad host range style of life. Their optimal growth temperature overlap with the optimal incubation temperature for eggs, and they are able to kill up to 90% of the embryos. Environmental forcing, e.g., tidal inundation and clay/silt content of nests, were correlated to disease development. Thus, these Fusarium species constitute a major threat to sea turtle nests, especially to those experiencing environmental stressors. These findings have serious implications for the survival of endangered sea turtle populations and the success of conservation programs worldwide.

Climate change has indirect effects on resource use and overlap among coexisting bird species with negative consequences for their reproductive success.

PubMed

Auer, Sonya K; Martin, Thomas E

2013-02-01

Climate change can modify ecological interactions, but whether it can have cascading effects throughout ecological networks of multiple interacting species remains poorly studied. Climate-driven alterations in the intensity of plant-herbivore interactions may have particularly profound effects on the larger community because plants provide habitat for a wide diversity of organisms. Here we show that changes in vegetation over the last 21 years, due to climate effects on plant-herbivore interactions, have consequences for songbird nest site overlap and breeding success. Browsing-induced reductions in the availability of preferred nesting sites for two of three ground nesting songbirds led to increasing overlap in nest site characteristics among all three bird species with increasingly negative consequences for reproductive success over the long term. These results demonstrate that changes in the vegetation community from effects of climate change on plant-herbivore interactions can cause subtle shifts in ecological interactions that have critical demographic ramifications for other species in the larger community. © 2012 Blackwell Publishing Ltd.

Snakes in the Eagle’s Nest: A History of Ground Attacks on Air Bases,

DTIC Science & Technology

1995-01-01

CRETE The New Zealand Division (7,700 personnel) was deployed in the Maleme-Canea-Suda Bay area. Although its 5th Brigade was re- sponsible for the...forces. In contrast, the New Zealand defense of Maleme was hampered by their obsession with the seaborne threat to Suda Bay . The New Zealand ...attack on Crete. • New Zealand ground commanders on Crete failed to devote suf- ficient resources to the defense of Maleme Airfield. • German

Seasonal changes in serum gonadal steroids associated with migration, mating, and nesting in the loggerhead sea turtle (Caretta caretta).

PubMed

Wibbels, T; Owens, D W; Limpus, C J; Reed, P C; Amoss, M S

1990-07-01

Adult male loggerhead sea turtles, Caretta caretta, exhibited a "prenuptial" spermatogenic cycle that was coincident with increased concentrations of serum testosterone (T). Serum T was high during the months when migration and mating have been recorded for males. In contrast to females, males appear to be annual breeders. Nine reproductively active female C. caretta (as verified through laparoscopy) were tagged with sonic transmitters and were repeatedly bled prior to migration. Four months prior to the nesting season, the ovaries of reproductively active females had hundreds of vitellogenic follicles of approximately 1.5 cm in diameter (i.e., half the size of ovulatory follicles). Approximately 4-6 weeks prior to migration from feeding grounds to mating and nesting areas, serum estradiol-17 beta (E2) concentrations increased significantly and remained high for approximately 4 weeks, suggesting a period of increased vitellogenesis. During a 1- to 2-week period prior to migration, serum E2 decreased significantly, while serum T concentrations increased (at least) until the time of migration. Serum T, E2, and progesterone (PRO) were elevated during nesting if a turtle was going to nest again during that nesting season. During the last nesting of a season, turtles had low serum concentrations of T, E2, and Pro. The prenuptial pattern of gonadal recrudescence and gonadal steroid production in both male and female C. caretta contrasts with those of many temperate freshwater turtles, and this type of reproductive pattern may have been facilitated by adaptation to a tropical marine environment.

Long-range movements and breeding dispersal of Prairie Falcons from southwest Idaho

USGS Publications Warehouse

Steenhof, K.; Fuller, M.R.; Kochert, M.N.; Bates, K.K.

2005-01-01

From 1999-2003, we tracked movements of adult female Prairie Falcons (Falco mexicanus) using satellite telemetry to characterize long-range movement patterns and breeding dispersal. We radio marked 40 falcons from April-May on their nesting grounds in the Snake River Birds of Prey National Conservation Area in southwest Idaho. All falcons with functioning transmitters left the Snake River Canyon from late June through mid-July. Most headed northeast across the Continental Divide to summering areas in Montana, Alberta, Saskatchewan, and the Dakotas. Prairie Falcons stayed at their northern summer areas for 1-4 months before heading to the southern Great Plains or to southwest Idaho. The Great Plains was a key migration pathway. Important wintering areas included the Texas Panhandle and southwest Idaho. Most falcons completed their seasonal migrations within 2 weeks. Use of widely separated nesting, summering, and wintering areas appears to be a strategy to exploit seasonally abundant prey resources. Most falcons had three or fewer use areas during the nonbreeding season, and falcons showed a high degree of fidelity to their use areas during each season. At least 21 falcons returned to nest within 2.5 km of where they nested in the previous year, but one falcon moved to a new nesting area 124 km south of her previous breeding area. Prairie Falcon movements suggest large-scale connectivity of grassland and shrubsteppe landscapes throughout western North America. Conservation of Prairie Falcons must be an international effort that considers habitats used during both nesting and non-nesting seasons. ?? The Cooper Ornithological Society 2005.

Effects of hydropeaking on the spawning behaviour of Atlantic salmon Salmo salar and brown trout Salmo trutta.

PubMed

Vollset, K W; Skoglund, H; Wiers, T; Barlaup, B T

2016-06-01

An in situ camera set-up was used to study the spawning activity of Atlantic salmon Salmo salar and brown trout Salmo trutta throughout two consecutive seasons in a spawning area affected by hydropower-related pulse flows due to hydropeaking. The purpose was to test whether the flow variation discouraged spawning in shallow areas or motivated spawning into areas with elevated risk of incubation mortality. There were more S. salar observed on the spawning ground during days with high discharge. The presence of S. salar in the spawning grounds was not affected by the hydropeaking cycles of the preceding night. Female S. salar were observed preparing nests within the first hour after water discharge had increased to levels suitable for spawning. In contrast, the number of S. trutta was not correlated with flow and nest preparation was also observed at a discharge corresponding to the lowest discharge levels during a hydropeaking cycle. Survival was generally high in nests excavated the following winter, with only 5·4% suffering mortality due to dewatering. The results suggest that S. salar may respond rapidly to variable-flow conditions and utilize short windows with suitable flows for spawning. Smaller S. trutta may utilize low-flow conditions to spawn in areas that are not habitable by larger S. salar during low flow. © 2016 The Fisheries Society of the British Isles.

Interphyletic relationships in the use of nesting cavities: mutualism, competition and amensalism among hymenopterans and vertebrates

NASA Astrophysics Data System (ADS)

Veiga, José P.; Wamiti, Wanyoike; Polo, Vicente; Muchai, Muchane

2013-09-01

Although competition is usually assumed to be the most common interaction between closely related organisms that share limiting resources, the relationships linking distant taxa that use the same nesting sites are poorly understood. In the present study, we examine the interactions among social hymenopterans (honeybees and wasps) and vertebrates in tropical ecosystems of East Africa. By analysing the preferences of these three groups for nest boxes that were empty or previously occupied by a different taxon, we try to establish whether the relationships among them are commensal, mutualistic, competitive or amensal. Vertebrates and honeybees selected nest boxes that had previously been occupied by the other, which suggests that each obtains some benefit from the other. This relationship can be considered mutualistic, although a mutual preference for each others' nests does not exclude a competitive interaction. Vertebrates and wasps preferred nest boxes not previously occupied by the other, which suggests that they compete for tree cavities. Finally, wasps seemed to completely refuse cavities previously used by honeybees, while the bees occupied cavities regardless of whether they had been previously used by wasps, an apparently amensal relationship. These results indicate that the interdependence between distantly related taxa is stronger and more complex than previously described, which may have important implications for population dynamics and community structure.

Fine-scale thermal adaptation in a green turtle nesting population

PubMed Central

Weber, Sam B.; Broderick, Annette C.; Groothuis, Ton G. G.; Ellick, Jacqui; Godley, Brendan J.; Blount, Jonathan D.

2012-01-01

The effect of climate warming on the reproductive success of ectothermic animals is currently a subject of major conservation concern. However, for many threatened species, we still know surprisingly little about the extent of naturally occurring adaptive variation in heat-tolerance. Here, we show that the thermal tolerances of green turtle (Chelonia mydas) embryos in a single, island-breeding population have diverged in response to the contrasting incubation temperatures of nesting beaches just a few kilometres apart. In natural nests and in a common-garden rearing experiment, the offspring of females nesting on a naturally hot (black sand) beach survived better and grew larger at hot incubation temperatures compared with the offspring of females nesting on a cooler (pale sand) beach nearby. These differences were owing to shallower thermal reaction norms in the hot beach population, rather than shifts in thermal optima, and could not be explained by egg-mediated maternal effects. Our results suggest that marine turtle nesting behaviour can drive adaptive differentiation at remarkably fine spatial scales, and have important implications for how we define conservation units for protection. In particular, previous studies may have underestimated the extent of adaptive structuring in marine turtle populations that may significantly affect their capacity to respond to environmental change. PMID:21937495

Egg accumulation with 3D embryos provides insight into the life history of a pterosaur.

PubMed

Wang, Xiaolin; Kellner, Alexander W A; Jiang, Shunxing; Cheng, Xin; Wang, Qiang; Ma, Yingxia; Paidoula, Yahefujiang; Rodrigues, Taissa; Chen, He; Sayão, Juliana M; Li, Ning; Zhang, Jialiang; Bantim, Renan A M; Meng, Xi; Zhang, Xinjun; Qiu, Rui; Zhou, Zhonghe

2017-12-01

Fossil eggs and embryos that provide unique information about the reproduction and early growth of vertebrates are exceedingly rare, particularly for pterosaurs. Here we report on hundreds of three-dimensional (3D) eggs of the species Hamipterus tianshanensis from a Lower Cretaceous site in China, 16 of which contain embryonic remains. Computed tomography scanning, osteohistology, and micropreparation reveal that some bones lack extensive ossification in potentially late-term embryos, suggesting that hatchlings might have been flightless and less precocious than previously assumed. The geological context, including at least four levels with embryos and eggs, indicates that this deposit was formed by a rare combination of events, with storms acting on a nesting ground. This discovery supports colonial nesting behavior and potential nesting site fidelity in the Pterosauria. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Tool use by Amazonian capuchin monkeys during predation on caiman nests in a high-productivity forest.

PubMed

Torralvo, Kelly; Rabelo, Rafael M; Andrade, Alfredo; Botero-Arias, Robinson

2017-04-01

Descriptions of new tool-use events are important for understanding how ecological context may drive the evolution of tool use among primate traditions. Here, we report a possible case of the first record of tool use by wild Amazonian capuchin monkeys (Sapajus macrocephalus). The record was made by a camera trap, while we were monitoring caiman nest predation at Mamirauá Reserve in Central Amazonia. An adult individual was registered in a bipedal posture, apparently using a branch as a shovel to dig eggs out of a nest. Caiman eggs are frequently depredated by opportunistic animals, such as the capuchin monkeys. As the Mamirauá Reserve is covered by a high-productivity forest, and caiman eggs are a high-quality food resource seasonally available on the ground, we believe that tool use by capuchins is more likely to be opportunity driven, rather than necessity driven, in our study site.

Estimating population size of Pygoscelid Penguins from TM data

NASA Technical Reports Server (NTRS)

Olson, Charles E., Jr.; Schwaller, Mathew R.; Dahmer, Paul A.

1987-01-01

An estimate was made toward a continent wide population of penguins. The results indicate that Thematic Mapper data can be used to identify penguin rookeries due to the unique reflectance properties of guano. Strong correlations exist between nesting populations and rookery area occupied by the birds. These correlations allow estimation of the number of nesting pairs in colonies. The success of remote sensing and biometric analyses leads one to believe that a continent wide estimate of penguin populations is possible based on a timely sample employing ground based and remote sensing techniques. Satellite remote sensing along the coastline may well locate previously undiscovered penguin nesting sites, or locate rookeries which have been assumed to exist for over a half century, but never located. Observations which found that penguins are one of the most sensitive elements in the complex of Southern Ocean ecosystems motivated this study.

KSC-2010-1352

NASA Image and Video Library

2010-01-19

CAPE CANAVERAL, Fla. - Brown pelicans enjoy a respite from the winter temperatures at the Turn Basin in Launch Complex 39 at NASA's Kennedy Space Center in Florida. Behind them is the Pegasus barge, often used to transport the space shuttle's external tanks into the basin, and NASA's News Center. The brown pelican is found along the coast in California and from North Carolina to Texas, Mexico, the West Indies and many Caribbean Islands, as well as Guyana and Venezuela in South America. It is listed as endangered only in Louisiana, Mississippi, and in the Caribbean. The species is considered to be long-lived. One pelican captured in Edgewater, Fla., in November 1964, was found to have been banded in September 1933, over 31 years previously. Individuals can weigh up to eight pounds, with larger pelicans having wing spreads of over seven feet. Their nests are usually built in mangrove trees, but ground nesting may also occur. Nesting takes place mostly in early spring or summer with the male carrying nesting materials to the female. Although the female builds the nest, both share in incubation and rearing duties. The Merritt Island National Wildlife Refuge coexists with Kennedy Space Center and provides a habitat for 330 species of birds including brown pelicans. Photo credit: NASA/Jack Pfaller

Abiotic vs. biotic influences on habitat selection of coexisting species: Climate change impacts?

USGS Publications Warehouse

Martin, T.E.

2001-01-01

Species are commonly segregated along gradients of microclimate and vegetation. I explore the question of whether segregation is the result of microhabitat partitioning (biotic effects) or choice of differing microclimates (abiotic effects). I explored this question for four ground-nesting bird species that are segregated along a microclimate and vegetation gradient in Arizona. Birds shifted position of their nests on the microhabitat and microclimate gradient in response to changing precipitation over nine years. Similarly, annual bird abundance varied with precipitation across 12 yr. Those shifts in abundance and nesting microhabitat with changing precipitation demonstrate the importance of abiotic influences on bird distributions and habitat choice. However, nest-site shifts and microhabitat use also appear to be influenced by interactions among coexisting species. Moreover, shifts in habitat use by all species caused nest predation (i.e., biotic) costs that increased with increasing distance along the microclimate gradient. These results indicate that abiotic and biotic costs can strongly interact to influence microhabitat choice and abundances of coexisting species. Global climate change impacts have been considered largely in terms of simple distributional shifts, but these results indicate that shifts can also increase biotic costs when species move into habitat types for which they are poorly adapted or that create new biotic interactions.

Mechanistic understanding of the effects of natural gas development on sagebrush-obligate songbird nest predation rates

NASA Astrophysics Data System (ADS)

Hethcoat, Matthew G.

Natural gas development has rapidly increased within sagebrush ( Artemisia spp.) dominated landscapes of the Intermountain West. Prior research in the Upper Green River Basin, Wyoming demonstrated increased nest predation of sagebrush-obligate songbirds with higher densities of natural gas wells. To better understand the mechanisms underlying this pattern, I assessed this commonly used index of oil and gas development intensity (well density) for estimating habitat transformation and predicting nest survival for songbirds breeding in energy fields during 2008- 2009 and 2011-2012. We calculated landscape metrics (habitat loss, amount of edge, patch shape complexity, and mean patch size) to identify the aspect of landscape transformation most captured by well density. Well density was most positively associated with the amount of habitat loss within 1 square kilometer. Daily nest survival was relatively invariant with respect to well density for all three species. In contrast, nest survival rates of all three species consistently decreased with increased surrounding habitat loss due to energy development. Thus, although well density and habitat loss were strongly correlated, at times they provided contrasting estimates of nest survival probability. Additionally, we tested the hypothesis that surrounding habitat loss influenced local nest predation rates via increased predator activity. During 2011- 2012, we surveyed predators and monitored songbird nests at twelve sites in western Wyoming. Nine species, representing four mammalian and three avian families, were video-recorded depredating eggs and nestlings. Approximately 75% of depredation events were caused by rodents. While chipmunk (Tamias minimus) detections were negatively associated with increased habitat loss, mice (Peromyscus maniculatus and Reithrodontomys megalotis) and ground squirrels (Ictidomys tridecemlineatus and Urocitellus armatus) increased with greater surrounding habitat loss. Consistent with our predictions, nest survival significantly declined at study locations with greater predator activity for Brewer's Sparrows (Spizella breweri) and Sagebrush Sparrows (Artemisiospiza nevadensis ). Our work is among the few studies which have identified mechanisms underlying increased nest predation rates, linking predation patterns, nest predators, and human-induced habitat alteration. Our results demonstrate the importance of simultaneous study of habitat change, predators, and prey in understanding the mechanisms by which evolved predator-prey relationships can be affected by human-induced rapid environmental change.

Region-wide trends of nesting ospreys in northwestern Mexico: a three-decade perspective

USGS Publications Warehouse

Henny, Charles J.; Anderson, Daniel W.; Vera, Aradit Castellanos; Cartron, Jean-Luc E.

2008-01-01

We used a double-sampling technique (air plus ground survey) in 2006, with partial double coverage, to estimate the present size of the Osprey (Pandion haliaetus) nesting population in northwestern Mexico (coastal Baja California, islands in the Gulf of California, and coastal Sonora and Sinaloa). With the exception of Natividad, Cedros, and San Benitos islands along the Pacific coast of Baja California (all three excluded from our coverage in 2006 due to fog), this survey was a repeat of previous surveys conducted by us with the same protocol in 1977 and 1992/1993, allowing for estimates of regional population trends. The minimum population estimate for the area we surveyed in 2006 was 1343 nesting pairs, an 81% increase since 1977, but only a 3% increase since 1992/1993. The population on the Gulf side of Baja California generally remained stable during the three surveys (255, 236, and 252 pairs, respectively). The population of the Midriff Islands (Gulf of California in the vicinity of 29°N latitude) remained similar from 1992/1993 (308 pairs) to 2006 (289 pairs), but with notable population changes on the largest two islands (Guardian Angel: 45 to 105 pairs [133% increase]; Tiburón: 164 to 109 pairs [34% decrease]). The minimum estimated Osprey population on the Sonora mainland decreased in a manner similar to adjacent Isla Tiburón, i.e., by 26%, from 214 pairs in 1993 to 158 pairs in 2006. In contrast, the population in coastal Sinaloa, which had increased by 150% between 1977 and 1993, grew again by 58% between 1993 and 2006, from 180 to 285 pairs. Our survey confirmed previously described patterns of rapid population changes at a local level, coupled with apparent shifts in spatial distribution. The large ground-nesting population that until recently nested on two islands in San Ignacio Lagoon ( Pacific Ocean side, Baja California) was no longer present on the islands in 2006, but an equivalent number of pairs were found to the north and south of the lagoon, nesting in small towns and along adjoining overhead electric lines, with no overall change in population size for that general area (198 pairs in 1992; 199 in 2006). Use of artificial nesting structures was 4.3% in 1977 and 6.2% in 1992/1993, but jumped to 26.4% in 2006. Use of poles that support overhead electric lines poses a risk of electrocution to Ospreys and also causes power outages and fires. We recommend modification of these poles to safely accommodate Osprey nests, as has been successfully accomplished in many countries.

The Greening of St Patrick's.

ERIC Educational Resources Information Center

Barron, Jennie

1993-01-01

The grade 6-7 class at St. Patrick's School in Hamilton (Ontario) engages in outdoor environmental projects to enhance classroom learning. Some student activities have been (1) worm composting; (2) tree planting; (3) restoring tern nesting areas; and (4) planning and cultivating a sophisticated garden on school grounds. (KS)

A life history study of the yellow throat

USGS Publications Warehouse

Stewart, R.E.

1953-01-01

Investigations concerning the life history of the Yellow-throat were made in southern Michigan during the spring and summer of 1938. Supplementary information was also obtained at Arlington, Virginia, in 1940 and at the Patuxent Research Refuge, Maryland, in 1947.....Resident males established territories almost immediately upon arrival in spring. In southern Michigan some resident males arrived at least as soon as, if not before, transient males. Most females appeared on their nesting ground about a week later. Adults were engaged in nesting activities from the time of their arrival in spring until the advent of the post-nuptial molt in late summer.....Typical Yellow-throat habitat consists of a mixture of a dense herbaceous vegetation and small woody plants in damp or wet situations. At Ann Arbor, the Yellow-throat was a common breeding species in its restricted suitable habitat. The population density in one area of suitable habitat was about 69 territorial males per 100 acres. Of 11 territorial males that were intensively studied, one was polygamous (with two mates), nine were monogamous, and one was probably monogamous (with at least one mate).....The song of the individual Yellow-throat was heard throughout the breeding season except for the courtship period. Two major types of song were the common song given while perched, and an occasional, more elaborate, flight song. Most males sing in spurts, singing at fairly regular intervals for a considerable period and then abruptly ceasing for another period. The vocabulary of both sexes included several types of call notes that appeared either to have special functions or to represent outward expressions of distinct emotional states of the bird.....Resident males were antagonistic toward each other throughout the breeding season. Most remained on well-established territories during this period. Territories of 10 monogamous males ranged in size from .8 to 1.8 acres but the territory of one polygamous male occupied. 3.4 acres. The behavior of males during inter-territorial encounters was similar in some respects to their behavior when courting females.....While courting females, the males are very attentive and seldom sing for about one week. During the courtship period the female locates the nesting site and builds the nest without assistance from the male.....Nests, constructed of dried plant materials, were situated on or near the ground and were supported on all sides by stems of herbaceous plants or limbs of shrubs. Many nests were composed of three layers with the coarser materials being used in the outer layer.....The full clutch of eggs in 12 nests ranged from 4 to 6 (average, 4.6). Early clutches seem to be larger than later ones. After the first egg is laid, one is laid on each succeeding day until the clutch is complete. Incubation period is about 12 days. Incubation is only by the female. Records of daytime incubation schedules of three females about half way through incubation indicate that the periods spent on and off the nests average about 61 and 16 minutes, respectively.....Young Yellow-throats usually remain in the nest for eight or nine days. During this period they grow and develop rapidly. Their weight quintuples in six days. Both sexes are active in feeding the young and in removing excreta from the nest. Records of feeding at three nests showed a range of one feeding per 5 1/2 minutes to one feeding per 22 minutes, the rate increasing with age of young. Adults care for the young for at least two weeks after the young leave the nest.....Ten of 12 females that were intensively studied were successful in raising young beyond the nestling stage. Only one of these raised two broods, although three females built at least three nests each. In 19 nests, 11 (58 per cent) produced nestlings and 7 (37 per cent) produced fledglings. In total, the 19 nests produced an average of one fledgling Yellow-throat per nest. Of 22 nests that were found near Ann Arbor, 10 (45

Cowbird removals unexpectedly increase productivity of a brood parasite and the songbird host.

PubMed

Kosciuch, Karl L; Sandercock, Brett K

2008-03-01

Generalist brood parasites reduce productivity and population growth of avian hosts and have been implicated in population declines of several songbirds of conservation concern. To estimate the demographic effects of brood parasitism on Bell's Vireos (Vireo bellii), we removed Brown-headed Cowbirds (Molothrus ater) in a replicated switchback experimental design. Cowbird removals decreased parasitism frequency from 77% and 85% at unmanipulated plots to 58% and 47% at removal plots in 2004 and 2005, respectively. Vireo productivity per pair was higher at cowbird removal plots when years were pooled (mean = 2.6 +/- 0.2 [SE] young per pair) compared to unmanipulated plots (1.2 +/- 0.1). Nest desertion frequency was lower at cowbird removal plots (35% of parasitized nests) compared to unmanipulated plots (69%) because removal of host eggs was the proximate cue for nest desertion, and vireos experienced lower rates of egg loss at cowbird removal plots. Nest success was higher among unparasitized than parasitized nests, and parasitized nests at cowbird removal plots had a higher probability of success than parasitized nests at unmanipulated plots. Unexpectedly, cowbird productivity from vireo pairs was higher at cowbird removal plots (mean = 0.3 +/- 0.06 young per pair) than at unmanipulated plots (0.1 +/- 0.03) because fewer parasitized nests were deserted and the probability of nest success was higher. Our study provides the first evidence that increases in cowbird productivity may be an unintended consequence of cowbird control programs, especially during the initial years of trapping when parasitism may only be moderately reduced. Thus, understanding the demographic impacts of cowbird removals requires an informed understanding of the behavioral ecology of host-parasite interactions.

Impacts of tree rows on grassland birds & potential nest predators: A removal experiment

USGS Publications Warehouse

Ellison, Kevin S.; Ribic, Christine; Sample, David W.; Fawcett, Megan J.; Dadisman, John D.

2013-01-01

Globally, grasslands and the wildlife that inhabit them are widely imperiled. Encroachment by shrubs and trees has widely impacted grasslands in the past 150 years. In North America, most grassland birds avoid nesting near woody vegetation. Because woody vegetation fragments grasslands and potential nest predator diversity and abundance is often greater along wooded edge and grassland transitions, we measured the impacts of removing rows of trees and shrubs that intersected grasslands on potential nest predators and the three most abundant grassland bird species (Henslow’s sparrow [Ammodramus henslowii], Eastern meadowlark [Sturnella magna], and bobolink [Dolichonyx oryzivorus]) at sites in Wisconsin, U.S.A. We monitored 3 control and 3 treatment sites, for 1 yr prior to and 3 yr after tree row removal at the treatment sites. Grassland bird densities increased (2–4 times for bobolink and Henslow’s sparrow) and nesting densities increased (all 3 species) in the removal areas compared to control areas. After removals, Henslow’s sparrows nested within ≤50 m of the treatment area, where they did not occur when tree rows were present. Most dramatically, activity by woodland-associated predators nearly ceased (nine-fold decrease for raccoon [Procyon lotor]) at the removals and grassland predators increased (up to 27 times activity for thirteen-lined ground squirrel [Ictidomys tridecemlineatus]). Nest success did not increase, likely reflecting the increase in grassland predators. However, more nests were attempted by all 3 species (175 versus 116) and the number of successful nests for bobolinks and Henslow’s sparrows increased. Because of gains in habitat, increased use by birds, greater production of young, and the effective removal of woodland-associated predators, tree row removal, where appropriate based on the predator community, can be a beneficial management action for conserving grassland birds and improving fragmented and degraded grassland ecosystems.

Impacts of Tree Rows on Grassland Birds and Potential Nest Predators: A Removal Experiment

PubMed Central

Ellison, Kevin S.; Ribic, Christine A.; Sample, David W.; Fawcett, Megan J.; Dadisman, John D.

2013-01-01

Globally, grasslands and the wildlife that inhabit them are widely imperiled. Encroachment by shrubs and trees has widely impacted grasslands in the past 150 years. In North America, most grassland birds avoid nesting near woody vegetation. Because woody vegetation fragments grasslands and potential nest predator diversity and abundance is often greater along wooded edge and grassland transitions, we measured the impacts of removing rows of trees and shrubs that intersected grasslands on potential nest predators and the three most abundant grassland bird species (Henslow’s sparrow [Ammodramus henslowii], Eastern meadowlark [Sturnella magna], and bobolink [Dolichonyx oryzivorus]) at sites in Wisconsin, U.S.A. We monitored 3 control and 3 treatment sites, for 1 yr prior to and 3 yr after tree row removal at the treatment sites. Grassland bird densities increased (2–4 times for bobolink and Henslow’s sparrow) and nesting densities increased (all 3 species) in the removal areas compared to control areas. After removals, Henslow’s sparrows nested within ≤50 m of the treatment area, where they did not occur when tree rows were present. Most dramatically, activity by woodland-associated predators nearly ceased (nine-fold decrease for raccoon [Procyon lotor]) at the removals and grassland predators increased (up to 27 times activity for thirteen-lined ground squirrel [Ictidomys tridecemlineatus]). Nest success did not increase, likely reflecting the increase in grassland predators. However, more nests were attempted by all 3 species (175 versus 116) and the number of successful nests for bobolinks and Henslow’s sparrows increased. Because of gains in habitat, increased use by birds, greater production of young, and the effective removal of woodland-associated predators, tree row removal, where appropriate based on the predator community, can be a beneficial management action for conserving grassland birds and improving fragmented and degraded grassland ecosystems. PMID:23565144

Quantitative analysis of American woodcock nest and brood habitat

USGS Publications Warehouse

Bourgeois, A.; Keppie, Daniel M.; Owen, Ray B.

1977-01-01

Sixteen nest and 19 brood sites of American woodcock (Philohela minoI) were examined in northern lower Michigan between 15 April and 15 June 1974 to determine habitat structure associated with these sites. Woodcock hens utilized young, second-growth forest stands which were similar in species composition for both nesting and brood rearing. A multi-varIate discriminant function analysis revealed a significant (P< 0.05) difference, however, in habitat structure. Nest habitat was characterized by lower tree density (2176 trees/ha) and basal area (8.6 m2/ha), by being close to forest openings (7 m) and by being situated on dry, relatively well drained sites. In contrast, woodcock broods were located in sites that had nearly twice the tree density (3934 trees/hal and basal area (16.5 m2/ha), was located over twice as far from forest openings (18 m) and generally occurred on damp sites, near (8 m) standing water. Importance of the habitat features to the species and possible management implications are discussed.

A Nutritional Profile of the Trap-Nesting Wasp Trypoxylon lactitarse (Hymenoptera: Crabronidae): Comparison of Sexes and Overwintering and Non-Overwintering Generations

PubMed Central

Judd, Timothy M.; Fasnacht, Matthew P.

2017-01-01

The wasp Trypoxylon lactitarse Saussure is a bivoltine trap-nesting species that possesses a non-overwintering generation (G1) and a generation that overwinters as a prepupa (G2). Thus, the nutritional needs of the G1 individuals were predicted to be different than the G2 because the latter generation needs to store energy prior to diapause. Trap-nesting Trypoxylon are also of interest because, unlike most Hymenoptera, the males guard the nest while females forage. Thus, males may lose nutrients as they stay and guard the nest. In this study, a nutritional profile was created for T. lactitarse to compare the macronutrient (protein, carbohydrates, and lipids) and micronutrient (Ca, Cu, Fe, K, Mg, Mn, Na, and Zn) levels of the different life stages of the wasp and compare individuals of the G1 and G2 generations. There were distinct changes in the nutrient levels relative to the original food source as individuals metamorphosed into larvae, pupae, and adults. G1 larvae had higher levels of carbohydrates than G2 larvae. G2 larvae had higher levels of lipids and K than G1 larvae, indicating possible differences in energy storage. In adults, there was an increase in levels of carbohydrates and Mn. Parental males, which stay and guard the nest, were found to have higher levels of carbohydrates at the end of the nesting period than females and emerging adults. One possible implication is that females may feed males during the nesting period, as the females are the only individuals to forage. PMID:28054943

A Nutritional Profile of the Trap-Nesting Wasp Trypoxylon lactitarse (Hymenoptera: Crabronidae): Comparison of Sexes and Overwintering and Non-Overwintering Generations.

PubMed

Judd, Timothy M; Fasnacht, Matthew P

2017-01-03

The wasp Trypoxylon lactitarse Saussure is a bivoltine trap-nesting species that possesses a non-overwintering generation (G1) and a generation that overwinters as a prepupa (G2). Thus, the nutritional needs of the G1 individuals were predicted to be different than the G2 because the latter generation needs to store energy prior to diapause. Trap-nesting Trypoxylon are also of interest because, unlike most Hymenoptera, the males guard the nest while females forage. Thus, males may lose nutrients as they stay and guard the nest. In this study, a nutritional profile was created for T. lactitarse to compare the macronutrient (protein, carbohydrates, and lipids) and micronutrient (Ca, Cu, Fe, K, Mg, Mn, Na, and Zn) levels of the different life stages of the wasp and compare individuals of the G1 and G2 generations. There were distinct changes in the nutrient levels relative to the original food source as individuals metamorphosed into larvae, pupae, and adults. G1 larvae had higher levels of carbohydrates than G2 larvae. G2 larvae had higher levels of lipids and K than G1 larvae, indicating possible differences in energy storage. In adults, there was an increase in levels of carbohydrates and Mn. Parental males, which stay and guard the nest, were found to have higher levels of carbohydrates at the end of the nesting period than females and emerging adults. One possible implication is that females may feed males during the nesting period, as the females are the only individuals to forage.

Species-specific differences in the fine structure of learning walk elements in Cataglyphis ants.

PubMed

Fleischmann, Pauline N; Grob, Robin; Wehner, Rüdiger; Rössler, Wolfgang

2017-07-01

Cataglyphis desert ants are famous navigators. Like all central place foragers, they are confronted with the challenge to return home, i.e. relocate an inconspicuous nest entrance in the ground, after their extensive foraging trips. When leaving the underground nest for the first time, desert ants perform a striking behavior, so-called learning walks that are well structured. However, it is still unclear how the ants initially acquire the information needed for sky- and landmark-based navigation, in particular how they calibrate their compass system at the beginning of their foraging careers. Using high-speed video analyses, we show that different Cataglyphis species include different types of characteristic turns in their learning walks. Pirouettes are full or partial rotations (tight turns about the vertical body axis) during which the ants frequently stop and gaze back in the direction of the nest entrance during the longest stopping phases. In contrast, voltes are small walked circles without directed stopping phases. Interestingly, only Cataglyphis ant species living in a cluttered, and therefore visually rich, environment (i.e. C. noda and C. aenescens in southern Greece) perform both voltes and pirouettes. They look back to the nest entrance during pirouettes, most probably to take snapshots of the surroundings. In contrast, C. fortis inhabiting featureless saltpans in Tunisia perform only voltes and do not stop during these turns to gaze back at the nest - even if a set of artificial landmarks surrounds the nest entrance. © 2017. Published by The Company of Biologists Ltd.

Growth and survival of Mountain Plovers

USGS Publications Warehouse

Miller, Brian J.; Knopf, Fritz L.

1993-01-01

Growth and survival rates of Mountain Plovers (Charadrius montanus) were monitored using radiotelemetry from hatching until birds left the breeding grounds on the Pawnee National Grassland, Weld County, Colorado. Chick weights increased logarithmically (r) = 0.961) and tarsus length linearly (r = 0.948) with age. Using the average fledgling weight of 69.8 g and an age/weight regression we predicted that the average age at fledging was 36 d. Fourteen Mountain Plover nests each had three effs; an average of 2.6 eggs hatched in seven nests, whereas remaining nests were lost to predation, storms, or trampling by a cow. Twenty-four adult Mountain Plovers were monitored for 275 telemetry days with no mortalities. Twenty flightless chicks had a calculated daily survival rate of 0.979 for 233 telemetry-days. Mortalities of flightless chicks were due to predation or unknown causes. The daily survival rate predicted that 1.2 of the 2.6 chicks hatched per nest lived to fly. Eight fledged chicks were monitored for 74 telemetry-days, with a daily survival rate of 0.974. Mortalities of fledglings were all attributed to predation. The combined survival rates predicted that 0.7 or the 2.6 hatched chicks lived to leave the nesting area. Survival rates of flightless chicks were similar to those reported 20 yr ago, implying that recent declines in Mountain Plover numbers on the continent are not attributable to either longer-term declines in nesting productivity or phenomena occurring at non-breeding locales.

The decline of an adaptation in the absence of a presumed selection pressure

USGS Publications Warehouse

Cruz, A.; Wiley, J.W.

1989-01-01

The colonial nesting Village Weaver (Ploceus cucullatus) lays eggs that vary in ground color and pattern, but individual females lay similar eggs each time. Tests on captive African stocks have shown that females reject eggs of other cohorts if such eggs are sufficiently different.

Plant guide: Munro's globemallow (Sphaeralcea munroana)

Treesearch

Pamela L. S. Pavek; James H. Cane; Olga A. Kildisheva; Anthony S. Davis

2011-01-01

Munro's globemallow attracts many species of bees, a few of which are specialists, requiring pollen and nectar only from Sphaeralcea and related genera. These include the ground-nesting bees Diadasia diminuta, D. lutzi, and Colletes sphaeralcea. The Diadasia are proficient and dedicated pollinators, and have been found colonizing trial plots on research farms (...

Hawksbill satellite-tracking case study: Implications for remigration interval and population estimates

USGS Publications Warehouse

Sartain-Iverson, Autumn R.; Hart, Kristen M.; Fujisaki, Ikuko; Cherkiss, Michael S.; Pollock, Clayton; Lundgren, Ian; Hillis-Starr, Zandy

2016-01-01

Hawksbill sea turtles (Eretmochelys imbricata) are circumtropically distributed and listed as Critically Endangered by the IUCN (Meylan & Donnelly 1999; NMFS & USFWS 1993). To aid in population recovery and protection, the Hawksbill Recovery Plan identified the need to determine demographic information for hawksbills, such as distribution, abundance, seasonal movements, foraging areas (sections 121 and 2211), growth rates, and survivorship (section 2213, NMFS & USFWS 1993). Mark-recapture analyses are helpful in estimating demographic parameters and have been used for hawksbills throughout the Caribbean (e.g., Richardson et al. 1999; Velez-Zuazo et al. 2008); integral to these studies are recaptures at the nesting site as well as remigration interval estimates (Hays 2000). Estimates of remigration intervals (the duration between nesting seasons) are critical to marine turtle population estimates and measures of nesting success (Hays 2000; Richardson et al. 1999). Although hawksbills in the Caribbean generally show natal philopatry and nesting-site fidelity (Bass et al. 1996; Bowen et al. 2007), exceptions to this have been observed for hawksbills and other marine turtles (Bowen & Karl 2007; Diamond 1976; Esteban et al. 2015; Hart et al. 2013). This flexibility in choosing a nesting beach could therefore affect the apparent remigration interval and subsequently, region-wide population counts.

Beyond harm’s reach? Submersion of river turtle nesting areas and implications for restoration actions after Amazon hydropower development

PubMed Central

Michalski, Fernanda; Gibbs, James P.

2018-01-01

The global expansion of energy demands combined with abundant rainfall, large water volumes and high flow in tropical rivers have led to an unprecedented expansion of dam constructions in the Amazon. This expansion generates an urgent need for refined approaches to river management; specifically a move away from decision-making governed by overly generalized guidelines. For the first time we quantify direct impacts of hydropower reservoir establishment on an Amazon fresh water turtle. We conducted surveys along 150 km of rivers upstream of a new dam construction during the low water months that correspond to the nesting season of Podocnemis unifilis in the study area. Comparison of nest-areas before (2011, 2015) and after (2016) reservoir filling show that reservoir impacts extend 13% beyond legally defined limits. The submerged nesting areas accounted for a total of 3.8 ha of nesting habitat that was inundated as a direct result of the reservoir filling in 2016. Our findings highlight limitations in the development and implementation of existing Brazilian environmental impact assessment process. We also propose potential ways to mitigate the negative impacts of dams on freshwater turtles and the Amazonian freshwater ecosystems they inhabit. PMID:29333347

Beyond harm's reach? Submersion of river turtle nesting areas and implications for restoration actions after Amazon hydropower development.

PubMed

Norris, Darren; Michalski, Fernanda; Gibbs, James P

2018-01-01

The global expansion of energy demands combined with abundant rainfall, large water volumes and high flow in tropical rivers have led to an unprecedented expansion of dam constructions in the Amazon. This expansion generates an urgent need for refined approaches to river management; specifically a move away from decision-making governed by overly generalized guidelines. For the first time we quantify direct impacts of hydropower reservoir establishment on an Amazon fresh water turtle. We conducted surveys along 150 km of rivers upstream of a new dam construction during the low water months that correspond to the nesting season of Podocnemis unifilis in the study area. Comparison of nest-areas before (2011, 2015) and after (2016) reservoir filling show that reservoir impacts extend 13% beyond legally defined limits. The submerged nesting areas accounted for a total of 3.8 ha of nesting habitat that was inundated as a direct result of the reservoir filling in 2016. Our findings highlight limitations in the development and implementation of existing Brazilian environmental impact assessment process. We also propose potential ways to mitigate the negative impacts of dams on freshwater turtles and the Amazonian freshwater ecosystems they inhabit.

A risk assessment approach to manage inundation of Elseya albagula nests in impounded waters: a win-win situation?

PubMed

McDougall, A J; Espinoza, T; Hollier, C; Limpus, D J; Limpus, C J

2015-03-01

A risk assessment process was used to trial the impact of potential new operating rules on the frequency of nest inundation for the White-throated snapping turtle, Elseya albagula, in the impounded waters of the Burnett River, Queensland, Australia. The proposed operating rules would increase the barrage storage level during the turtle nesting season (May-July) and then would be allowed to reduce to a lower level for incubation for the rest of the year. These proposed operating rules reduce rates of nest inundation by altering water levels in the Ben Anderson Barrage impoundment of the Burnett River. The rules operate throughout the turtle reproductive period and concomitantly improve stability of littoral habitat and fishway operation. Additionally, the proposed rules are expected to have positive socio-economic benefits within the region. While regulated water resources will inherently have a number of negative environmental implications, these potential new operating rules have the capacity to benefit the environment while managing resources in a more sustainable manner. The operating rules have now been enacted in subordinate legislation and require the operator to maintain water levels to minimize turtle nest inundation.

A Risk Assessment Approach to Manage Inundation of Elseya albagula Nests in Impounded Waters: A Win-Win Situation?

NASA Astrophysics Data System (ADS)

McDougall, A. J.; Espinoza, T.; Hollier, C.; Limpus, D. J.; Limpus, C. J.

2015-03-01

A risk assessment process was used to trial the impact of potential new operating rules on the frequency of nest inundation for the White-throated snapping turtle, Elseya albagula, in the impounded waters of the Burnett River, Queensland, Australia. The proposed operating rules would increase the barrage storage level during the turtle nesting season (May-July) and then would be allowed to reduce to a lower level for incubation for the rest of the year. These proposed operating rules reduce rates of nest inundation by altering water levels in the Ben Anderson Barrage impoundment of the Burnett River. The rules operate throughout the turtle reproductive period and concomitantly improve stability of littoral habitat and fishway operation. Additionally, the proposed rules are expected to have positive socio-economic benefits within the region. While regulated water resources will inherently have a number of negative environmental implications, these potential new operating rules have the capacity to benefit the environment while managing resources in a more sustainable manner. The operating rules have now been enacted in subordinate legislation and require the operator to maintain water levels to minimize turtle nest inundation.

Ecology and behavior of the zenaida dove

USGS Publications Warehouse

Wiley, J.W.

1991-01-01

Data are summarized from a 10 year study of the Zenaida Dove (Zenaida aurita) in Puerto Rico and its offshore islands. The dove displays sexual size dimorphism, with males generally larger than females: Most activities (feeding, courtship, fighting) occurred in mornings and afternoons, whereas loafing and maintenance activities were more prevalent at mid-day. I recorded 77 plant species used as food by Zenaida Doves in Puerto Rico. Major food species uncluded Scleria lithosperma, Argemone mexicana, Croton rigidus, Phyllanthus amarus, Cordia angustifolia, Zanthoxylum martinicense, Euphorbia heterophylla, and several species of legumes. Zenaida Doves have two major vocalizations: the 'Coo', or Advertisement Call, given in assertive and sexual contexts, and the Nest Call, primarily used at or near the nest. Doves nested in a wide variety of habitats, including forest edge, mangrove forest, dry scrub, and mixed agriculture-urban areas. Nests were generally placed in trees, but doves nested on the ground where certain terrestrial predators were absent. Nests were found in all months of the year, although a breeding peak occurred from March through Mayor July. Doves replaced clutches when nests were destroyed, and recycled up to four times in a season. Males selected nest sites and initiated building. Eggs (2) were laid on alternate days, beginning about two days after the nest was completed. Incubation and nestling stages averaged 13.9 :t 0.5 [SE] and 14.3 :t 0.6 days. The male attended the nest from mid-morning (X = 08:59 hr) through mid-afternoon (x = 16:53), then the female took over incubation and brooding duties for the night. Nests were continuously covered from the laying of the first egg through day seven of the nestling stage. Thereafter, adult attendance dropped steadily until day 14, when they carne to the nest only for chick feedings. Chicks (days 0-15) showed a mean daily weight gain of 18.3% and attained a fledging weight of about 120g (81% of adult weight). The mean daily growth (culmen, tarsometatarsus, ulna) was 6.8% (range = 4.0-9.8% daily). Dove productivity varied among and within study areas over the 10 years. Mean number of chicks hatched per nest that held eggs ranged from 0.3 to 1.6 for 3 study areas. Mean number fledged per nest ranged from 0.3 to 1.4. Productivity was lowest in the dry southwestern Puerto Rico study area (Susua and Guanica forests; x = 0.7 chicks fledged per nest) and was highest for the lower montane mixed agriculture/urban area (Cidra; 1.2). Populations nesting in scrub and mangrove forests (Roosevelt Roads Naval Station) fledged an average of 0.9 chicks/nest. Nest success followed a similar geographic pattern: southwestern Puerto Rico -40.9% of nests with eggs were successful, Cidra -62.6%, and Roosevelt Roads -52.0%. The most important sources of dove egg and chick loss were Pearly-eyed Thrashers (Margarops fuscatus -49% of losses) and roof rats (Rattus rattus -16%).

Species-specific variation in nesting and postfledging resource selection for two forest breeding migrant songbirds.

PubMed

Jenkins, Julianna M A; Thompson, Frank R; Faaborg, John

2017-01-01

Habitat selection is a fundamental component of community ecology, population ecology, and evolutionary biology and can be especially important to species with complex annual habitat requirements, such as migratory birds. Resource preferences on the breeding grounds may change during the postfledging period for migrant songbirds, however, the degree to which selection changes, timing of change, and whether all or only a few species alter their resource use is unclear. We compared resource selection for nest sites and resource selection by postfledging juvenile ovenbirds (Seiurus aurocapilla) and Acadian flycatchers (Empidonax virescens) followed with radio telemetry in Missouri mature forest fragments from 2012-2015. We used Bayesian discrete choice modeling to evaluate support for local vegetation characteristics on the probability of selection for nest sites and locations utilized by different ages of postfledging juveniles. Patterns of resource selection variation were species-specific. Resource selection models indicated that Acadian flycatcher habitat selection criteria were similar for nesting and dependent postfledging juveniles and selection criteria diverged when juveniles became independent from adults. After independence, flycatcher resource selection was more associated with understory foliage density. Ovenbirds differed in selection criteria between the nesting and postfledging periods. Fledgling ovenbirds selected areas with higher densities of understory structure compared to nest sites, and the effect of foliage density on selection increased as juveniles aged and gained independence. The differences observed between two sympatric forest nesting species, in both the timing and degree of change in resource selection criteria over the course of the breeding season, illustrates the importance of considering species-specific traits and postfledging requirements when developing conservation efforts, especially when foraging guilds or prey bases differ. We recommend that postfledging habitat selection be considered in future conservation efforts dealing with Neotropical migrants and other forest breeding songbirds.

Parasitism at the landscape scale: Cowbirds prefer forests

USGS Publications Warehouse

Hahn, D.C.; Hatfield, J.S.

1995-01-01

Landscape-scale examination of parasitism patterns of Brown-headed Cowbirds (Molothrus ater) revealed heterogeneous parasitism rates across the mosaic of a forest and associated oldfield communities. In a two-year study in Dutchess County, New York, we found a significantly higher parasitism rate in the forest-interior community (n = 301 nests; 17 species) than on the species in the adjacent and nearby old-field and edge (n = 328 nests; 15 species; 32.3% versus 6.5%; p lt 0.0001). Cowbirds invaded a mature 1300-ha forest stand even when their traditional host species were available in adjacent old-field and edge habitats. The forest and old field study areas were located in a 38,000-ha township with 55% forest cover and contained numerous agriculture, dairy, and horse farms that provided favorable habitat for cowbirds, within-forest examination of parasitism patterns revealed four aspects of cowbird parasitism that contrasted with patterns described in other regions; (1) parasitism was concentrated significantly more often on ground and low-nesting (nests ltoreq 1 m) forest species than on medium- and high nesting species (nests gt 1 m; 35. 01 % versus 2993%; p = 0.0393); (2) parasitism was not significantly greater on Neotropical migrant species than on short-distance migrants and residents; (3) the parasitism rate was not higher in nests close to edges; and (4) the parasitism level was low on certain forest species (such as Wood Thrush) that have experienced high parasitism levels in the Midwest. From a management perspective these data suggest that cowbirds exhibit regional differences in host and habitat use; the target host community of a particular cowbird population is unpredictable at the landscape scale; and a landscape scale should be used in designing cowbird studies to accurately assess local population dynamics.

Degradation of mangrove tissues by arboreal termites (Nasutitermes acajutlae) and their role in the mangrove C cycle (Puerto Rico): Chemical characterization and organic matter provenance using bulk δ13C, C/N, alkaline CuO oxidation-GC/MS, and solid-state 13C NMR

NASA Astrophysics Data System (ADS)

Vane, Christopher H.; Kim, Alexander W.; Moss-Hayes, Vicky; Snape, Colin E.; Diaz, Miguel Castro; Khan, Nicole S.; Engelhart, Simon E.; Horton, Benjamin P.

2013-08-01

Arboreal termites are wood decaying organisms that play an important role in the first stages of C cycling in mangrove systems. The chemical composition of Rhizophora mangle, Avicennia germinans, and Laguncularia racemosa leaf, stem, and pneumatophore tissues as well as associated sediments was compared to that of nests of the termite Nasutitermes acajutlae. Nests gave δ13C values of -26.1 to -27.2‰ (±0.1) and C/N of 43.3 (±2.0) to 98.6 (±16.2) which were similar to all stem and pneumatophores but distinct from mangrove leaves or sediments. Organic matter processed by termites yielded lignin phenol concentrations (Λ, lambda) that were 2-4 times higher than stem or pneumatophores and 10-20 times higher than that of leaves or sediments, suggesting that the nests were more resistant to biodegradation than the mangrove vegetation source. 13C NMR revealed that polysaccharide content of mangrove tissues (50-69% C) was higher than that of the nests (46-51% C). Conversely, lignin accounted for 16.2-19.6% C of nest material, a threefold increase relative to living mangrove tissues; a similar increase in aromatic methoxyl content was also observed in the nests. Lipids (aliphatic and paraffinic moieties) were also important but rather variable chemical components of all three mangrove species, representing between 13.5 and 28.3% of the C content. Termite nests contained 3.14 Mg C ha-1 which represents approximately 2% of above ground C storage in mangroves, a value that is likely to increase upon burial due to their refractory chemical composition.

The ethological trap: functional and numerical responses of highly efficient invasive predators driving prey extinctions.

PubMed

Spencer, Ricky-John; Van Dyke, James U; Thompson, Michael B

2016-10-01

Ecological traps are threats to organisms, and exist in a range of biological systems. A subset of ecological trap theory is the "ethological trap," whereby behaviors canalized by past natural selection become traps when environments change rapidly. Invasive predators are major threats to imperiled species and their ability to exploit canalized behaviors of naive prey is particularly important for the establishment of the predator and the decline of the native prey. Our study uses ecological theory to demonstrate that invasive predator controls require shifts in management priorities. Total predation rate (i.e., total response) is the product of both the functional response and numerical response of predators to prey. Functional responses are the changes in the rate of prey consumption by individual predators, relative to prey abundance. Numerical responses are the aggregative rates of prey consumption by all predators relative to prey density, which change with predator density via reproduction or migration, in response to changes in prey density. Traditional invasive predator management methods focus on reducing predator populations, and thus manage for numerical responses. These management efforts fail to manage for functional responses, and may not eliminate impacts of highly efficient individual predators. We explore this problem by modeling the impacts of functional and numerical responses of invasive foxes depredating imperiled Australian turtle nests. Foxes exhibit exceptionally efficient functional responses. A single fox can destroy >95% of turtle nests in a nesting area, which eliminates juvenile recruitment. In this case, the ethological trap is the "Arribada" nesting strategy, an emergent behavior whereby most turtles in a population nest simultaneously in the same nesting grounds. Our models show that Arribada nesting events do not oversaturate foxes, and small numbers of foxes depredate all of the nests in a given Arribada. Widely scattering nests may reduce fox predation rates, but the long generation times of turtles combined with their rapid recent decline suggests that evolutionary responses in nesting strategy may be unlikely. Our study demonstrates that reducing populations of highly efficient invasive predators is insufficient for preserving native prey species. Instead, management must reduce individual predator efficiency, independent of reducing predator population size. © 2016 by the Ecological Society of America.

Microhabitat Conditions in Wyoming’s Sage-Grouse Core Areas: Effects on Nest Site Selection and Success

PubMed Central

Beck, Jeffrey L.; Kirol, Christopher P.; Pratt, Aaron C.; Conover, Michael R.

2016-01-01

The purpose of our study was to identify microhabitat characteristics of greater sage-grouse (Centrocercus urophasianus) nest site selection and survival to determine the quality of sage-grouse habitat in 5 regions of central and southwest Wyoming associated with Wyoming’s Core Area Policy. Wyoming’s Core Area Policy was enacted in 2008 to reduce human disturbance near the greatest densities of sage-grouse. Our analyses aimed to assess sage-grouse nest selection and success at multiple micro-spatial scales. We obtained microhabitat data from 928 sage-grouse nest locations and 819 random microhabitat locations from 2008–2014. Nest success was estimated from 924 nests with survival data. Sage-grouse selected nests with greater sagebrush cover and height, visual obstruction, and number of small gaps between shrubs (gap size ≥0.5 m and <1.0 m), while selecting for less bare ground and rock. With the exception of more small gaps between shrubs, we did not find any differences in availability of these microhabitat characteristics between locations within and outside of Core Areas. In addition, we found little supporting evidence that sage-grouse were selecting different nest sites in Core Areas relative to areas outside of Core. The Kaplan-Meier nest success estimate for a 27-day incubation period was 42.0% (95% CI: 38.4–45.9%). Risk of nest failure was negatively associated with greater rock and more medium-sized gaps between shrubs (gap size ≥2.0 m and <3.0 m). Within our study areas, Wyoming’s Core Areas did not have differing microhabitat quality compared to outside of Core Areas. The close proximity of our locations within and outside of Core Areas likely explained our lack of finding differences in microhabitat quality among locations within these landscapes. However, the Core Area Policy is most likely to conserve high quality habitat at larger spatial scales, which over decades may have cascading effects on microhabitat quality available between areas within and outside of Core Areas. PMID:27002531

Identification of Naegleria fowleri in warm ground water aquifers.

PubMed

Laseke, Ian; Korte, Jill; Lamendella, Regina; Kaneshiro, Edna S; Marciano-Cabral, Francine; Oerther, Daniel B

2010-01-01

The free-living amoeba Naegleria fowleri was identified as the etiological agent of primary amoebic meningoencephalitis that caused the deaths of two children in Peoria, Arizona, in autumn of 2002. It was suspected that the source of N. fowleri was the domestic water supply, which originates from ground water sources. In this study, ground water from the greater Phoenix Metropolitan area was tested for the presence of N. fowleri using a nested polymerase chain reaction approach. Phylogenetic analyses of 16S rRNA sequences of bacterial populations in the ground water were performed to examine the potential link between the presence of N. fowleri and bacterial groups inhabiting water wells. The results showed the presence of N. fowleri in five out of six wells sampled and in 26.6% of all ground water samples tested. Phylogenetic analyses showed that beta- and gamma-proteobacteria were the dominant bacterial populations present in the ground water. Bacterial community analyses revealed a very diverse community structure in ground water samples testing positive for N. fowleri.

Habitat Selection and Behaviour of a Reintroduced Passerine: Linking Experimental Restoration, Behaviour and Habitat Ecology

PubMed Central

Bennett, Victoria A.; Doerr, Veronica A. J.; Doerr, Erik D.; Manning, Adrian D.; Lindenmayer, David B.; Yoon, Hwan-Jin

2013-01-01

Habitat restoration can play an important role in recovering functioning ecosystems and improving biodiversity. Restoration may be particularly important in improving habitat prior to species reintroductions. We reintroduced seven brown treecreeper (Climacteris picumnus) social groups into two nature reserves in the Australian Capital Territory in south-eastern Australia. This study provided a unique opportunity to understand the interactions between restoration ecology, behavioural ecology and habitat ecology. We examined how experimental restoration treatments (addition of coarse woody debris, variations in ground vegetation cover and nest box installation) influenced the behaviour and microhabitat use of radio-tracked individuals to evaluate the success of restoration treatments. The addition of coarse woody debris benefited the brown treecreeper through increasing the probability of foraging on a log or on the ground. This demonstrated the value of using behaviour as a bio-indicator for restoration success. Based on previous research, we predicted that variations in levels of ground vegetation cover would influence behaviour and substrate use, particularly that brown treecreepers would choose sites with sparse ground cover because this allows better access to food and better vigilance for predators. However, there was little effect of this treatment, which was likely influenced by the limited overall use of the ground layer. There was also little effect of nest boxes on behaviour or substrate use. These results somewhat confound our understanding of the species based on research from extant populations. Our results also have a significant impact regarding using existing knowledge on a species to inform how it will respond to reintroduction and habitat restoration. This study also places great emphasis on the value of applying an experimental framework to ecological restoration, particularly when reintroductions produce unexpected outcomes. PMID:23349923

Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs

USGS Publications Warehouse

Eagles-Smith, Collin A.; Ackerman, Joshua T.

2009-01-01

Small fish are commonly used to assess mercury (Hg) risk to wildlife and monitor Hg in wetlands. However, limited research has evaluated short-term Hg variability in small fish, which can have important implications for monitoring programs and risk assessment. We conducted a time-series study of Hg concentrations in two small fish species representing benthic (longjaw mudsuckers [Gillichthys mirabilis]) and pelagic (threespine sticklebacks [Gasterosteus aculeatus]) food-webs within three wetland habitats in San Francisco Bay Estuary. We simultaneously monitored prey deliveries, nest initiation, and chick hatching dates of breeding Forster's terns (Sterna forsteri), the most abundant nesting piscivore in the region. Mudsuckers and sticklebacks were the predominant prey fish, comprising 36% and 25% of tern diet, and Hg concentrations averaged (geometric mean ?? SE, ??g/g dw) 0.44 ?? 0.01 and 0.68 ?? 0.03, respectively. Fish Hg concentrations varied substantially over time following a quadratic form in both species, increasing 40% between March and May then decreasing 40% between May and July. Importantly, Forster's terns initiated 68% of nests and 31% of chicks hatched during the period of peak Hg concentrations in prey fish. These results illustrate the importance of short-term temporal variation in small fish Hg concentrations for both Hg monitoring programs and assessing wildlife risk.

An assessment of the efficacy and peak catch rates of emergence tents for measuring bee nesting.

PubMed

Pane, Alexander M; Harmon-Threatt, Alexandra N

2017-06-01

Emergence tents are a new tool used to understand nesting ecology of ground nesting bee species. However, many questions remain about how to use tents effectively. We assessed (a) variance in tent capture rates over time, (b) the effects of site characteristics on proportion of tents capturing bees, and (c) the effect of soil characteristics on nest site choice. Emergence tents were placed out for one week in May, June, and August and checked daily. Soil, bee, and floral characteristics were recorded. Across all sites and months the average number of tents capturing bees was less than 20% during one week of sampling, but this varied between sites. Tent captures decreased after 48 h deployment, but accumulation differed seasonally, with slower accumulation of total bees caught in May than in June or August. Although capture rates were not affected by bee or floral abundance, soil moisture beneath a tent influenced where bees were captured. Effective use of emergence tents may require adjusting the length of deployment depending on season and will require a minimum of 48 h installation to help maximize efficacy. The overall low capture rates demonstrate the need to optimize emergence tent use.

Effects of harness-attached transmitters on premigration and reproduction of Brant

USGS Publications Warehouse

Ward, David H.; Flint, Paul L.

1995-01-01

Radio transmitters are an important tool in waterfowl ecology studies, but little is known about their effects on free-ranging geese. We attached transmitters to female brant (Branta bernicla nigricans) to investigate migration schedules at a fall staging area, return rates to nesting grounds, and nesting rates of returning females in subsequent breeding seasons. Radio-tagged females (n = 62) carried either 35-g back-mounted transmitters attached with ribbon harnesses, or 26- or 32-g back-mounted transmitters affixed with plastic-coated wire harnesses (Dwyer 1972). Arrival and departure schedules at Izembek Lagoon, Alaska, did not differ (P > 0.05) between radio-tagged females and the entire population in 1987-89. Color-banded females with transmitters returned to the breeding colony in subsequent nesting seasons (1988-92) at a lower (P ≤ 0.003) rate (≤4%) than color-banded females without transmitters (57-83%). The 1 returning color-banded female with a transmitter did not breed, while an average 90% of the returning color-banded females without transmitters nested in subsequent breeding seasons (P = 0.005). Back-mounted, harness-attached transmitters may bias data in studies of waterfowl behavior, productivity, and survival.

Local habitat and landscape influence predation of bird nests on afforested Mediterranean cropland

NASA Astrophysics Data System (ADS)

Sánchez-Oliver, J. S.; Rey Benayas, J. M.; Carrascal, L. M.

2014-07-01

Afforestation programs such as the one promoted by the EU Common Agrarian Policy have contributed to spread tree plantations on former cropland. Nevertheless these afforestations may cause severe damage to open habitat species, especially birds of high conservation value. We investigated predation of artificial bird nests at young tree plantations and at the open farmland habitat adjacent to the tree plantations in central Spain. Predation rates were very high at both tree plantations (95.6%) and open farmland habitat (94.2%) after two and three week exposure. Plantation edge/area ratio and development of the tree canopy decreased predation rates and plantation area and magpie (Pica pica) abundance increased predation rates within tree plantations, which were also affected by land use types around plantations. The area of nearby tree plantations (positive effect), distance to the tree plantation edge (negative effect), and habitat type (mainly attributable to the location of nests in vineyards) explained predation rates at open farmland habitat. We conclude that predation rates on artificial nests were particularly high and rapid at or nearby large plantations, with high numbers of magpies and low tree development, and located in homogenous landscapes dominated by herbaceous crops and pastures with no remnants of semi-natural woody vegetation. Landscape planning should not favour tree plantations as the ones studied here in Mediterranean agricultural areas that are highly valuable for ground-nesting bird species.

Crucial nesting habitat for gunnison sage-grouse: A spatially explicit hierarchical approach

USGS Publications Warehouse

Aldridge, Cameron L.; Saher, D.J.; Childers, T.M.; Stahlnecker, K.E.; Bowen, Z.H.

2012-01-01

Gunnison sage-grouse (Centrocercus minimus) is a species of special concern and is currently considered a candidate species under Endangered Species Act. Careful management is therefore required to ensure that suitable habitat is maintained, particularly because much of the species' current distribution is faced with exurban development pressures. We assessed hierarchical nest site selection patterns of Gunnison sage-grouse inhabiting the western portion of the Gunnison Basin, Colorado, USA, at multiple spatial scales, using logistic regression-based resource selection functions. Models were selected using Akaike Information Criterion corrected for small sample sizes (AIC c) and predictive surfaces were generated using model averaged relative probabilities. Landscape-scale factors that had the most influence on nest site selection included the proportion of sagebrush cover >5%, mean productivity, and density of 2 wheel-drive roads. The landscape-scale predictive surface captured 97% of known Gunnison sage-grouse nests within the top 5 of 10 prediction bins, implicating 57% of the basin as crucial nesting habitat. Crucial habitat identified by the landscape model was used to define the extent for patch-scale modeling efforts. Patch-scale variables that had the greatest influence on nest site selection were the proportion of big sagebrush cover >10%, distance to residential development, distance to high volume paved roads, and mean productivity. This model accurately predicted independent nest locations. The unique hierarchical structure of our models more accurately captures the nested nature of habitat selection, and allowed for increased discrimination within larger landscapes of suitable habitat. We extrapolated the landscape-scale model to the entire Gunnison Basin because of conservation concerns for this species. We believe this predictive surface is a valuable tool which can be incorporated into land use and conservation planning as well the assessment of future land-use scenarios. ?? 2011 The Wildlife Society.

Simulating correction of adjustable optics for an x-ray telescope

NASA Astrophysics Data System (ADS)

Aldcroft, Thomas L.; Schwartz, Daniel A.; Reid, Paul B.; Cotroneo, Vincenzo; Davis, William N.

2012-10-01

The next generation of large X-ray telescopes with sub-arcsecond resolution will require very thin, highly nested grazing incidence optics. To correct the low order figure errors resulting from initial manufacture, the mounting process, and the effects of going from 1 g during ground alignment to zero g on-orbit, we plan to adjust the shapes via piezoelectric "cells" deposited on the backs of the reflecting surfaces. This presentation investigates how well the corrections might be made. We take a benchmark conical glass element, 410×205 mm, with a 20×20 array of piezoelectric cells 19×9 mm in size. We use finite element analysis to calculate the influence function of each cell. We then simulate the correction via pseudo matrix inversion to calculate the stress to be applied by each cell, considering distortion due to gravity as calculated by finite element analysis, and by putative low order manufacturing distortions described by Legendre polynomials. We describe our algorithm and its performance, and the implications for the sensitivity of the resulting slope errors to the optimization strategy.

Isotope analysis reveals foraging area dichotomy for atlantic leatherback turtles.

PubMed

Caut, Stéphane; Fossette, Sabrina; Guirlet, Elodie; Angulo, Elena; Das, Krishna; Girondot, Marc; Georges, Jean-Yves

2008-03-26

The leatherback turtle (Dermochelys coriacea) has undergone a dramatic decline over the last 25 years, and this is believed to be primarily the result of mortality associated with fisheries bycatch followed by egg and nesting female harvest. Atlantic leatherback turtles undertake long migrations across ocean basins from subtropical and tropical nesting beaches to productive frontal areas. Migration between two nesting seasons can last 2 or 3 years, a time period termed the remigration interval (RI). Recent satellite transmitter data revealed that Atlantic leatherbacks follow two major dispersion patterns after nesting season, through the North Gulf Stream area or more eastward across the North Equatorial Current. However, information on the whole RI is lacking, precluding the accurate identification of feeding areas where conservation measures may need to be applied. Using stable isotopes as dietary tracers we determined the characteristics of feeding grounds of leatherback females nesting in French Guiana. During migration, 3-year RI females differed from 2-year RI females in their isotope values, implying differences in their choice of feeding habitats (offshore vs. more coastal) and foraging latitude (North Atlantic vs. West African coasts, respectively). Egg-yolk and blood isotope values are correlated in nesting females, indicating that egg analysis is a useful tool for assessing isotope values in these turtles, including adults when not available. Our results complement previous data on turtle movements during the first year following the nesting season, integrating the diet consumed during the year before nesting. We suggest that the French Guiana leatherback population segregates into two distinct isotopic groupings, and highlight the urgent need to determine the feeding habitats of the turtle in the Atlantic in order to protect this species from incidental take by commercial fisheries. Our results also emphasize the use of eggs, a less-invasive sampling material than blood, to assess isotopic data and feeding habits for adult female leatherbacks.

Isotope Analysis Reveals Foraging Area Dichotomy for Atlantic Leatherback Turtles

PubMed Central

Angulo, Elena; Das, Krishna; Girondot, Marc

2008-01-01

Background The leatherback turtle (Dermochelys coriacea) has undergone a dramatic decline over the last 25 years, and this is believed to be primarily the result of mortality associated with fisheries bycatch followed by egg and nesting female harvest. Atlantic leatherback turtles undertake long migrations across ocean basins from subtropical and tropical nesting beaches to productive frontal areas. Migration between two nesting seasons can last 2 or 3 years, a time period termed the remigration interval (RI). Recent satellite transmitter data revealed that Atlantic leatherbacks follow two major dispersion patterns after nesting season, through the North Gulf Stream area or more eastward across the North Equatorial Current. However, information on the whole RI is lacking, precluding the accurate identification of feeding areas where conservation measures may need to be applied. Methodology/Principal Findings Using stable isotopes as dietary tracers we determined the characteristics of feeding grounds of leatherback females nesting in French Guiana. During migration, 3-year RI females differed from 2-year RI females in their isotope values, implying differences in their choice of feeding habitats (offshore vs. more coastal) and foraging latitude (North Atlantic vs. West African coasts, respectively). Egg-yolk and blood isotope values are correlated in nesting females, indicating that egg analysis is a useful tool for assessing isotope values in these turtles, including adults when not available. Conclusions/Significance Our results complement previous data on turtle movements during the first year following the nesting season, integrating the diet consumed during the year before nesting. We suggest that the French Guiana leatherback population segregates into two distinct isotopic groupings, and highlight the urgent need to determine the feeding habitats of the turtle in the Atlantic in order to protect this species from incidental take by commercial fisheries. Our results also emphasize the use of eggs, a less-invasive sampling material than blood, to assess isotopic data and feeding habits for adult female leatherbacks. PMID:18365003

KSC-06pd0836

NASA Image and Video Library

2006-05-15

KENNEDY SPACE CENTER, FLA. -- These osprey chicks wait for lunch from one of their parents (look for the fish in the claws of the upper osprey). The nest is located on a pole in the parking lot of the NASA News Center. This is the third year the ospreys have raised a family at the site. Known as a fish hawk, ospreys select sites of opportunity, from trees and telephone poles to rocks or even flat ground. In the United States they are found from Alaska and Newfoundland to Florida and the Gulf Coast. Osprey nests are found throughout the Kennedy Space Center and nearby Merritt Island National Wildlife Refuge, which shares a boundary with the Center. Photo credit: NASA/George Shelton

78 FR 47612 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Sharpnose...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-06

... (primary constituent elements such as roost sites, nesting grounds, seasonal wetlands, water quality, tide... individual and population growth and for normal behavior; (2) Food, water, air, light, minerals, or other... Growth and for Normal Behavior Sharpnose shiners occur in fairly shallow, flowing water, often less than...

Systemic Change for RTI: Key Shifts for Practice

ERIC Educational Resources Information Center

Kozleski, Elizabeth B.; Huber, Jennifer J.

2010-01-01

RTI has the potential to meet the challenges of increasing diversity in student populations and the need for increasingly complex systems of instructional design. Three fundamental shifts in understanding systems and systems change must ground RTI policy and implementation work. First, RTI must be seen as an activity system nested within a larger…

Sisyphean Neoliberal Reforms: The Intractable Mythology of Student Growth and Achievement Master Narratives within the Testing and TFA Era

ERIC Educational Resources Information Center

Fisher-Ari, Teresa; Kavanagh, Kara M.; Martin, Anne

2017-01-01

Neoliberal discourses defining and measuring "student achievement" and "teacher success" through myopic high-stakes testing-driven criteria for "accountability," can perpetuate the very inequities these reforms purport to address. Nested within a five-year inquiry using grounded theory to investigate experiences of…

Food for early succession birds: relationships among arthropods, shrub vegetation, and soil

Treesearch

Richard N. Conner; Daniel Saenz; D. Brent Burt

2006-01-01

During spring and early summer, shrub- and herbaceous-level vegetation provides nesting and foraging habitat for many shrub-habitat birds. We examined relationships among arthropod biomass and abundance, foliage leaf surface area and weight, vegetation ground cover, soil characteristics, relative humidity, and temperature to evaluate what factors may influence...

78 FR 47831 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Graham's...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-06

... roost sites, nesting grounds, seasonal wetlands, water quality, tide, soil type) that are essential to... Federal Register on July 1, 1994 (59 FR 34271)), the Information Quality Act (section 515 of the Treasury... associated Information Quality Guidelines, provide criteria, establish procedures, and provide guidance to...

Landscape Simplification Constrains Adult Size in a Native Ground-Nesting Bee

PubMed Central

Renauld, Miles; Hutchinson, Alena; Loeb, Gregory; Poveda, Katja; Connelly, Heather

2016-01-01

Bees provide critical pollination services to 87% of angiosperm plants; however, the reliability of these services may become threatened as bee populations decline. Agricultural intensification, resulting in the simplification of environments at the landscape scale, greatly changes the quality and quantity of resources available for female bees to provision their offspring. These changes may alter or constrain the tradeoffs in maternal investment allocation between offspring size, number and sex required to maximize fitness. Here we investigate the relationship between landscape scale agricultural intensification and the size and number of individuals within a wild ground nesting bee species, Andrena nasonii. We show that agricultural intensification at the landscape scale was associated with a reduction in the average size of field collected A. nasonii adults in highly agricultural landscapes but not with the number of individuals collected. Small females carried significantly smaller (40%) pollen loads than large females, which is likely to have consequences for subsequent offspring production and fitness. Thus, landscape simplification is likely to constrain allocation of resources to offspring through a reduction in the overall quantity, quality and distribution of resources. PMID:26943127

Landscape Simplification Constrains Adult Size in a Native Ground-Nesting Bee.

PubMed

Renauld, Miles; Hutchinson, Alena; Loeb, Gregory; Poveda, Katja; Connelly, Heather

2016-01-01

Bees provide critical pollination services to 87% of angiosperm plants; however, the reliability of these services may become threatened as bee populations decline. Agricultural intensification, resulting in the simplification of environments at the landscape scale, greatly changes the quality and quantity of resources available for female bees to provision their offspring. These changes may alter or constrain the tradeoffs in maternal investment allocation between offspring size, number and sex required to maximize fitness. Here we investigate the relationship between landscape scale agricultural intensification and the size and number of individuals within a wild ground nesting bee species, Andrena nasonii. We show that agricultural intensification at the landscape scale was associated with a reduction in the average size of field collected A. nasonii adults in highly agricultural landscapes but not with the number of individuals collected. Small females carried significantly smaller (40%) pollen loads than large females, which is likely to have consequences for subsequent offspring production and fitness. Thus, landscape simplification is likely to constrain allocation of resources to offspring through a reduction in the overall quantity, quality and distribution of resources.

Common Starlings (Sturnus vulgaris) increasingly select for grazed areas with increasing distance-to-nest.

PubMed

Heldbjerg, Henning; Fox, Anthony D; Thellesen, Peder V; Dalby, Lars; Sunde, Peter

2017-01-01

The abundant and widespread Common Starling (Sturnus vulgaris) is currently declining across much of Europe due to landscape changes caused by agricultural intensification. The proximate mechanisms causing adverse effects to breeding Starlings are unclear, hampering our ability to implement cost-efficient agri-environmental schemes to restore populations to former levels. This study aimed to show how this central foraging farmland bird uses and selects land cover types in general and how use of foraging habitat changes in relation to distance from the nest. We attached GPS-loggers to 17 breeding Starlings at a Danish dairy cattle farm in 2015 and 2016 and analysed their use of different land cover types as a function of distance intervals from the nest and their relative availability. As expected for a central place forager, Starlings increasingly avoided potential foraging areas with greater distance-to-nest: areas ≥ 500 m were selected > 100 times less frequently than areas within 100 m. On average, Starlings selected the land cover category Grazed most frequently, followed by Short Grass, Bare Ground, Meadow and Winter Crops. Starlings compensated for elevated travel costs by showing increasing habitat selection the further they foraged from the nest. Our results highlight the importance of Grazed foraging habitats close to the nest site of breeding Starlings. The ecological capacity of intensively managed farmlands for insectivorous birds like the Starling is decreasing through conversion of the most strongly selected land cover type (Grazed) to the least selected (Winter Crops) which may be further exacerbated through spatial segregation of foraging and breeding habitats.

Common Starlings (Sturnus vulgaris) increasingly select for grazed areas with increasing distance-to-nest

PubMed Central

Fox, Anthony D.; Thellesen, Peder V.; Dalby, Lars; Sunde, Peter

2017-01-01

The abundant and widespread Common Starling (Sturnus vulgaris) is currently declining across much of Europe due to landscape changes caused by agricultural intensification. The proximate mechanisms causing adverse effects to breeding Starlings are unclear, hampering our ability to implement cost-efficient agri-environmental schemes to restore populations to former levels. This study aimed to show how this central foraging farmland bird uses and selects land cover types in general and how use of foraging habitat changes in relation to distance from the nest. We attached GPS-loggers to 17 breeding Starlings at a Danish dairy cattle farm in 2015 and 2016 and analysed their use of different land cover types as a function of distance intervals from the nest and their relative availability. As expected for a central place forager, Starlings increasingly avoided potential foraging areas with greater distance-to-nest: areas ≥ 500 m were selected > 100 times less frequently than areas within 100 m. On average, Starlings selected the land cover category Grazed most frequently, followed by Short Grass, Bare Ground, Meadow and Winter Crops. Starlings compensated for elevated travel costs by showing increasing habitat selection the further they foraged from the nest. Our results highlight the importance of Grazed foraging habitats close to the nest site of breeding Starlings. The ecological capacity of intensively managed farmlands for insectivorous birds like the Starling is decreasing through conversion of the most strongly selected land cover type (Grazed) to the least selected (Winter Crops) which may be further exacerbated through spatial segregation of foraging and breeding habitats. PMID:28771556

Foods and foraging of prairie striped skunks during the avian nesting season

USGS Publications Warehouse

Greenwood, R.J.; Sargeant, A.B.; Piehl, J.L.; Buhl, D.A.; Hanson, B.A.

1999-01-01

Food habits of prairie skunks are not well understood, yet such knowledge might provide insight into factors influencing nest depredation. We studied food habits of radiocollared adult striped skunks (Mephitis mephitis) during 1976-78 in North Dakota, where skunks are regarded as important predators of ground-nesting birds. Plant foods, primarily grain and sunflower seeds, occurred in a larger percentage of scats in spring (15 Apr 31 May) than summer (1 Jun 15 July, P=0.04), but overall, plant foods were a minor part of skunk diets. Animal foods, primarily birds (including eggs), small rodents, and insects occurred annually in a large percentage of scats of all skunks. These foods were acquired nearly exclusively in grasslands. Percentage of scats containing animal foods was similar, irrespective of sex, season, or year (P>0.45). In spring, vertebrates occurred in a smaller percentage of scats of females than males (P0.15). Insects were mostly adult and larval Coleoptera, larval Lepidoptera, and adult and nymph Orthoptera.

[Association of Constrictotermes cyphergaster Silvestri (Isoptera: Termitidae) with trees in the Brazilian Cerrado].

PubMed

Lima-Ribeiro, Matheus de S; Pinto, Míriam P; Costa, Shirley S; Nabout, João C; Rangel, Thiago F L V B; de Melo, Tatiana L; de Moura, Iona'i O

2006-01-01

Termites usually build nests differently shaped and characterized according to each species, to protect and keep society cohesion. Some species build nests in the ground, some prefer tree thunks or branches as support, whereas other dig galleries in the wood. The purpose of this study is to analyze the relationship between the occurrence of arboreal termites Constrictotermes cyphergaster Silvestri and tree species that support the nest of this species, in a Cerrado sensu strictu of the Serra de Caldas Novas, GO. Data suggest a association relationship between C. Cyphergaster and the tree species Qualea grandiflora Mart., Annona crassiflora Mart., Caryocar brasiliense Camb. and Plathymenia reticulata Benth., shown by high Qui-squared values (chi2 = 214.986, gl. = 20, P < 0.001). This relationship may be found among other termites and tree species, including Cerrado biome, and may be due to several factors, such as natural competitors and predators, toxin production by other tree species or benefits between associated species (facultative mutualism or facilitation).

Marine turtles used to assist Austronesian sailors reaching new islands.

PubMed

Wilmé, Lucienne; Waeber, Patrick O; Ganzhorn, Joerg U

2016-02-01

Austronesians colonized the islands of Rapa Nui, Hawaii, the Marquesas and Madagascar. All of these islands have been found to harbor Austronesian artifacts and also, all of them are known nesting sites for marine turtles. Turtles are well known for their transoceanic migrations, sometimes totalling thousands of miles, between feeding and nesting grounds. All marine turtles require land for nesting. Ancient Austronesians are known to have had outstanding navigation skills, which they used to adjust course directions. But these skills will have been insufficient to locate tiny, remote islands in the vast Indo-Pacific oceans. We postulate that the Austronesians must have had an understanding of the marine turtles' migration patterns and used this knowledge to locate remote and unknown islands. The depth and speed at which marine turtles migrate makes following them by outrigger canoes feasible. Humans have long capitalized on knowledge of animal behavior. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

The influence of habitat, prey abundance, sex, and breeding success on the ranging behavior of Prairie Falcons

USGS Publications Warehouse

Marzluff, J.M.; Kimsey, Bryan A.; Schueck, Linda S.; McFadzen, Mary E.; Vekasy, M.S.; Bednarz, James C.

1997-01-01

We studied the ranging behavior and habitat selection of radio-tagged Prairie Falcons (Falco mexicanus) during the breeding season in southwestern Idaho. The distribution and numbers of Townsend's ground squirrels (Spermophilus townsendii), the primary prey of Prairie Falcons in our study area, varied in response to drought during the study period. Prairie Falcons ranged over large areas (ca. 300 km2) and increased their foraging ranges in response to declining ground squirrels. Reptiles and birds were preyed upon most frequently when squirrels were rare. Males and females differed little in their use of space. Successful pairs ranged over smaller areas than non-nesters and unsuccessful pairs. Falcons nesting near habitat most suitable for ground squirrels ranged over smaller areas than those nesting farther from such habitat. Home ranges contained significantly more winterfat (Ceratoides lanata) and native perennial grasses (especially Poa secunda), and significantly less salt desert shrubs and exotic annual grasses than expected based on availability. Salt desert shrubs were found less than expected, based on availability in core areas within home ranges. Selection for winterfat and bluegrass in core areas was contingent upon selection at the larger scale of the home range; falcons with home ranges containing more winterfat and bluegrass than expected based on availability were less selective in their placement of core areas with respect to these habitats. We believe salient features of Prairie Falcon home ranges result largely from patchy distribution of landscape features associated with different densities and availabilities of Townsend's ground squirrels.

The First Occurrence in the Fossil Record of an Aquatic Avian Twig-Nest with Phoenicopteriformes Eggs: Evolutionary Implications

PubMed Central

Grellet-Tinner, Gerald; Murelaga, Xabier; Larrasoaña, Juan C.; Silveira, Luis F.; Olivares, Maitane; Ortega, Luis A.; Trimby, Patrick W.; Pascual, Ana

2012-01-01

Background We describe the first occurrence in the fossil record of an aquatic avian twig-nest with five eggs in situ (Early Miocene Tudela Formation, Ebro Basin, Spain). Extensive outcrops of this formation reveal autochthonous avian osteological and oological fossils that represent a single taxon identified as a basal phoenicopterid. Although the eggshell structure is definitively phoenicopterid, the characteristics of both the nest and the eggs are similar to those of modern grebes. These observations allow us to address the origin of the disparities between the sister taxa Podicipedidae and Phoenicopteridae crown clades, and traces the evolution of the nesting and reproductive environments for phoenicopteriforms. Methodology/Principal Findings Multi-disciplinary analyses performed on fossilized vegetation and eggshells from the eggs in the nest and its embedding sediments indicate that this new phoenicopterid thrived under a semi-arid climate in an oligohaline (seasonally mesohaline) shallow endorheic lacustine environment. High-end microcharacterizations including SEM, TEM, and EBSD techniques were pivotal to identifying these phoenicopterid eggshells. Anatomical comparisons of the fossil bones with those of Phoenicopteriformes and Podicipediformes crown clades and extinct palaelodids confirm that this avian fossil assemblage belongs to a new and basal phoenicopterid. Conclusions/Significance Although the Podicipediformes-Phoenicopteriformes sister group relationship is now well supported, flamingos and grebes exhibit feeding, reproductive, and nesting strategies that diverge significantly. Our multi-disciplinary study is the first to reveal that the phoenicopteriform reproductive behaviour, nesting ecology and nest characteristics derived from grebe-like type strategies to reach the extremely specialized conditions observed in modern flamingo crown groups. Furthermore, our study enables us to map ecological and reproductive characters on the Phoenicopteriformes evolutionary lineage. Our results demonstrate that the nesting paleoenvironments of flamingos were closely linked to the unique ecology of this locality, which is a direct result of special climatic (high evaporitic regime) and geological (fault system) conditions. PMID:23082136

Wired: impacts of increasing power line use by a growing bird population

NASA Astrophysics Data System (ADS)

Moreira, Francisco; Encarnação, Vitor; Rosa, Gonçalo; Gilbert, Nathalie; Infante, Samuel; Costa, Julieta; D'Amico, Marcello; Martins, Ricardo C.; Catry, Inês

2017-02-01

Power lines are increasingly widespread across many regions of the planet. Although these linear infrastructures are known for their negative impacts on bird populations, through collision and electrocution, some species take advantage of electricity pylons for nesting. In this case, estimation of the net impact of these infrastructures at the population level requires an assessment of trade-offs between positive and negative impacts. We compiled historical information (1958-2014) of the Portuguese white stork Ciconia ciconia population to analyze long-term changes in numbers, distribution range and use of nesting structures. White stork population size increased 660% up to 12000 breeding pairs between 1984 and 2014. In the same period, the proportion of nests on electricity pylons increased from 1% to 25%, likely facilitated by the 60% increase in the length of the very high tension power line grid (holding the majority of the nests) in the stork’s distribution range. No differences in breeding success were registered for storks nesting on electricity pylons versus other structures, but a high risk of mortality by collision and electrocution with power lines was estimated. We discuss the implications of this behavioral change, and of the management responses by power line companies, both for stork populations and for managers.

Estimates of vital rates for a declining loggerhead turtle (Caretta caretta) subpopulation: implications for management

USGS Publications Warehouse

Lamont, Margaret M.; Fujisaki, Ikuko; Carthy, Raymond R.

2014-01-01

Because subpopulations can differ geographically, genetically and/or phenotypically, using data from one subpopulation to derive vital rates for another, while often unavoidable, is not optimal. We used a two-state open robust design model to analyze a 14-year dataset (1998–2011) from the St. Joseph Peninsula, Florida (USA; 29.748°, −85.400°) which is the densest loggerhead (Caretta caretta) nesting beach in the Northern Gulf of Mexico subpopulation. For these analyses, 433 individuals were marked of which only 7.2 % were observed re-nesting in the study area in subsequent years during the study period. Survival was estimated at 0.86 and is among the highest estimates for all subpopulations in the Northwest Atlantic population. The robust model estimated a nesting assemblage size that ranged from 32 to 230 individuals each year with an annual average of 110. The model estimates indicated an overall population decline of 17 %. The results presented here for this nesting group represent the first estimates for this subpopulation. These data provide managers with information specific to this subpopulation that can be used to develop recovery plans and conduct subpopulation-specific modeling exercises explicit to the challenges faced by turtles nesting in this region.

Northern Pintail

USGS Publications Warehouse

Clark, Robert G.; Fleskes, Joseph P.; Guyn, Karla L.; Haukos, David A.; Austin, Jane E.; Miller, Michael R.

2014-01-01

This medium-sized dabbling duck of slender, elegant lines and conservative plumage coloration is circumpolar in distribution and abundant in North America, with core nesting habitat in Alaska and the Prairie Pothole Region of southern Canada and the northern Great Plains. Breeders favor shallow wetlands interspersed throughout prairie grasslands or arctic tundra. An early fall migrant, the species arrives on wintering areas beginning in August, after wing molt, often forming large roosting and feeding flocks on open, shallow wetlands and flooded agricultural fields. The birds consume grains, marsh plant seeds, and aquatic invertebrates throughout fall and winter.Northern Pintails are among the earliest nesting ducks in North America, beginning shortly after ice-out in many northern areas. Individuals form new pair bonds each winter but are highly promiscuous during the nesting season, with mated and unmated males often involved in vigorous, acrobatic Pursuit Flights. Annual nest success and productivity vary with water conditions, predation, and weather. Females build nests on the ground, often far from water. Only the female incubates; her mate leaves shortly after incubation begins. Ducklings hatch together in one day, follow the female to water after a day in the nest, and fledge by July or August. Adults and ducklings consume mainly aquatic invertebrates during the breeding season.Predators and farming operations destroy many thousands of Northern Pintail nests annually; farming has also greatly reduced the amount of quality nesting cover available. Winter habitats are threatened by water shortages, agricultural development, contamination, and urbanization. Periods of extended drought in prairie nesting regions have caused dramatic population declines, usually followed by periods of recovery. Over the long term, however, the continental population of Northern Pintails has declined significantly from 6 million birds in the early 1970s to less than 3 million in the late 1980s and early 1990s. Since then, the population appears to have stabilized; in 2013, the estimate was 3.3 million birds, a large number but below conservation goals despite favorable wetland conditions in much of the prairie breeding region. Ongoing conservation measures, however, such as habitat restoration and enhancement of agricultural lands, as well as prudent harvest management, suggest that Northern Pintails should have a secure future in North America.

Identification of distinct movement patterns in Pacific leatherback turtle populations influenced by ocean conditions.

PubMed

Bailey, Helen; Benson, Scott R; Shillinger, George L; Bograd, Steven J; Dutton, Peter H; Eckert, Scott A; Morreale, Stephen J; Paladino, Frank V; Eguchi, Tomoharu; Foley, David G; Block, Barbara A; Piedra, Rotney; Hitipeuw, Creusa; Tapilatu, Ricardo F; Spotila, James R

2012-04-01

Interactions with fisheries are believed to be a major cause of mortality for adult leatherback turtles (Dermochelys coriacea), which is of particular concern in the Pacific Ocean, where they have been rapidly declining. In order to identify where these interactions are occurring and how they may be reduced, it is essential first to understand the movements and behavior of leatherback turtles. There are two regional nesting populations in the East Pacific (EP) and West Pacific (WP), comprising multiple nesting sites. We synthesized tracking data from the two populations and compared their movement patterns. A switching state-space model was applied to 135 Argos satellite tracks to account for observation error, and to distinguish between migratory and area-restricted search behaviors. The tracking data, from the largest leatherback data set ever assembled, indicated that there was a high degree of spatial segregation between EP and WP leatherbacks. Area-restricted search behavior mainly occurred in the southeast Pacific for the EP leatherbacks, whereas the WP leatherbacks had several different search areas in the California Current, central North Pacific, South China Sea, off eastern Indonesia, and off southeastern Australia. We also extracted remotely sensed oceanographic data and applied a generalized linear mixed model to determine if leatherbacks exhibited different behavior in relation to environmental variables. For the WP population, the probability of area-restricted search behavior was positively correlated with chlorophyll-a concentration. This response was less strong in the EP population, but these turtles had a higher probability of search behavior where there was greater Ekman upwelling, which may increase the transport of nutrients and consequently prey availability. These divergent responses to oceanographic conditions have implications for leatherback vulnerability to fisheries interactions and to the effects of climate change. The occurrence of leatherback turtles within both coastal and pelagic areas means they have a high risk of exposure to many different fisheries, which may be very distant from their nesting sites. The EP leatherbacks have more limited foraging grounds than the WP leatherbacks, which could make them more susceptible to any temperature or prey changes that occur in response to climate change.

Cavity types and microclimate: implications for ecological, evolutionary, and conservation studies.

PubMed

Amat-Valero, M; Calero-Torralbo, M A; Václav, R; Valera, F

2014-11-01

The abiotic conditions of the immediate environment of organisms are key factors for a better understanding of ecological and evolutionary processes. Yet, information in this regard is biased towards some habitat types, landscapes, and organisms. Here, we present a 2-year comparative study of the microclimatic properties (temperature, relative humidity, and their fluctuation) of three cavity types (nest boxes, cavities in bridges, and burrows in sandy cliffs) in an arid environment. We found marked and consistent months-long differences in microclimate among the three cavity types. Nest boxes were colder than the other cavity types, with temperature oscillations being an order of magnitude higher than in other cavity types. In contrast, microclimate was very stable in burrows and cavities in bridges, the former being generally warmer and drier than the latter. We also discuss the biological implications of microclimatic conditions and its variation in different cavity types by presenting two case studies, namely the temperature-humidity index and water vapor pressure during the hatching period of an endotherm and the chilling period during the diapause of an ectotherm ectoparasite. We stress the need for comparative studies of the same organisms subjected to different microclimates given the important ecological, evolutionary, and conservation implications.

Post-fledging movements of white-tailed eagles: Conservation implications for wind-energy development.

PubMed

Balotari-Chiebao, Fabio; Villers, Alexandre; Ijäs, Asko; Ovaskainen, Otso; Repka, Sari; Laaksonen, Toni

2016-11-01

The presence of poorly sited wind farms raises concerns for wildlife, including birds of prey. Therefore, there is a need to extend the knowledge of the potential human-wildlife conflicts associated with wind energy. Here, we report on the movements and habitat use of post-fledging satellite-tagged white-tailed eagles in Finland, where wind-energy development is expected to increase in the near future. In particular, we examine the probability of a fledgling approaching a hypothetical turbine that is placed at different distances from the nest. We found that this probability is high at short distances but considerably decreases with increasing distances to the nest. A utilisation-availability analysis showed that the coast was the preferred habitat. We argue that avoiding construction between active nests and the shoreline, as well as adopting the currently 2-km buffer zone for turbine deployment, can avoid or minimise potential impacts on post-fledging white-tailed eagles.

Lesser prairie-chicken nest site selection, microclimate, and nest survival in association with vegetation response to a grassland restoration program

USGS Publications Warehouse

Boal, Clint W.; Grisham, Blake A.; Haukos, David A.; Zavaleta, Jennifer C.; Dixon, Charles

2014-01-01

Climate models predict that the region of the Great Plains Landscape Conservation Cooperative (GPLCC) will experience increased maximum and minimum temperatures, reduced frequency but greater intensity of precipitation events, and earlier springs. These climate changes along with different landscape management techniques may influence the persistence of the lesser prairie-chicken (Tympanuchus pallidicinctus), a candidate for protection under the Endangered Species Act and a priority species under the GPLCC, in positive or negative ways. The objectives of this study were to conduct (1) a literature review of lesser prairie-chicken nesting phenology and ecology, (2) an analysis of thermal aspects of lesser prairie-chicken nest microclimate data, and (3) an analysis of nest site selection, nest survival, and vegetation response to 10 years of tebuthiuron and/or grazing treatments. We found few reports in the literature containing useful data on the nesting phenology of lesser prairie-chickens; therefore, managers must rely on short-term observations and measurements of parameters that provide some predictive insight into climate impacts on nesting ecology. Our field studies showed that prairie-chickens on nests were able to maintain relatively consistent average nest temperature of 31 °C and nest humidities of 56.8 percent whereas average external temperatures (20.3–35.0 °C) and humidities (35.2–74.9 percent) varied widely throughout the 24 hour (hr) cycle. Grazing and herbicide treatments within our experimental areas were designed to be less intensive than in common practice. We determined nest locations by radio-tagging hen lesser prairie-chickens captured at leks, which are display grounds at which male lesser prairie-chickens aggregate and attempt to attract a female for mating. Because nest locations selected by hen lesser prairie-chicken are strongly associated with the lek at which they were captured, we assessed nesting habitat use on the basis of hens captured at individual leks, and then for all leks pooled. There was no clear pattern of selection for treatment type for nest placement among hens associated with individual leks; however, when hens from all leks were pooled, we found nesting lesser prairie-chickens selected control plots for nesting over plots that were grazed, treated with tebuthiuron, or were both grazed and treated with tebuthiuron. Overall, the probability of a nest surviving the incubation period was 0.57 for this study and did not vary significantly among treatment types. In contrast to nesting preference for untreated habitats, lek use exhibited no noticeable selection of treatment type. Over the 10 years of the habitat management study, there was 91 percent less sand shinnery oak (Quercus havardii) in treated areas than untreated areas. The removal of sand shinnery oak made environmental soil moisture more available for grasses and forbs to germinate and grow. Grasses increased by 149 percent and forbs increased by 257 percent in treated areas as compared to untreated areas throughout the study period. Our combined results, including our habitat selection analysis at the individual lek level, indicated that reduced rates of herbicide and short-duration grazing treatments were not detrimental to nesting lesser prairie-chickens and that populations of lesser prairie-chickens in shrub-dominated ecosystems may benefit from reduced rates of herbicide application and short duration of grazing that results in increased habitat heterogeneity.

Deforestation: risk of sex ratio distortion in hawksbill sea turtles.

PubMed

Kamel, Stephanie Jill; Mrosovsky, N

2006-06-01

Phenotypic sex in sea turtles is determined by nest incubation temperatures, with warmer temperatures producing females and cooler temperatures producing males. The common finding of highly skewed female-biased hatchling sex ratios in sea turtle populations could have serious repercussions for the long-term survival of these species and prompted us to examine the thermal profile of a relatively pristine hawksbill nesting beach in Guadeloupe, French West Indies. Data loggers placed at nest depth revealed that temperatures in the forested areas were significantly cooler than temperatures in the more open, deforested areas. Using these temperatures as a predictor of sex ratio, we were able to assess the relative contributions of the different beach zones to the primary sex ratio: significantly more males were likely to be produced in the forested areas. Coastal forests are therefore important male-producing areas for the hawksbill sea turtle, and this has urgent conservation implications. On Guadeloupe, as on many Caribbean islands, deforestation rates are high and show few signs of slowing, as there is continual pressure to develop beachfront areas. The destruction of coastal forest could have serious consequences both in terms of local nesting behavior and of regional demography through the effects on population sex ratios. Human alterations to nesting habitat in other reptile taxa have been shown to modify the thermal properties of nest sites in ways that can disrupt their ecology by allowing parasite transmission, increasing vulnerability to climate change, or rendering existing habitat unsuitable.

Effects of streambank fencing of pasture land on benthic macroinvertebrates and the quality of surface water and shallow ground water in the Big Spring Run basin of Mill Creek watershed, Lancaster County, Pennsylvania, 1993-2001

USGS Publications Warehouse

Galeone, Daniel G.; Brightbill, Robin A.; Low, Dennis J.; O'Brien, David L.

2006-01-01

Streambank fencing along stream channels in pastured areas and the exclusion of pasture animals from the channel are best-management practices designed to reduce nutrient and suspended-sediment yields from drainage basins. Establishment of vegetation in the fenced area helps to stabilize streambanks and provides better habitat for wildlife in and near the stream. This study documented the effectiveness of a 5- to 12-foot-wide buffer strip on the quality of surface water and near-stream ground water in a 1.42-mi2 treatment basin in Lancaster County, Pa. Two miles of stream were fenced in the basin in 1997 following a 3- to 4-year pre-treatment period of monitoring surface- and ground-water variables in the treatment and control basins. Changes in surface- and ground-water quality were monitored for about 4 years after fence installation. To alleviate problems in result interpretation associated with climatic and hydrologic variation over the study period, a nested experimental design including paired-basin and upstream/downstream components was used to study the effects of fencing on surface-water quality and benthic-macroinvertebrate communities. Five surface-water sites, one at the outlet of a 1.77-mi2 control basin (C-1), two sites in the treatment basin (T-3 and T-4) that were above any fence installation, and two sites (one at an upstream tributary site (T-2) and one at the outlet (T-1)) that were treated, were sampled intensively. Low-flow samples were collected at each site (approximately 25-30 per year at each site), and stormflow was sampled with automatic samplers at all sites except T-3. For each site where stormflow was sampled, from 35 to 60 percent of the storm events were sampled over the entire study period. Surface-water sites were sampled for analyses of nutrients, suspended sediment, and fecal streptococcus (only low-flow samples), with field parameters (only low-flow samples) measured during sample collection. Benthic-macroinvertebrate samples were collected in May and September of each year; samples were collected at the outlet of the control and treatment basins and at three upstream sites, two in the treatment basin and one in the control basin. For each benthic-macroinvertebrate sample: Stream riffles and pools were sampled using the kick-net method; habitat was characterized using Rapid Bioassessment Protocols (RBP); water-quality samples were collected for nutrients and suspended sediment; stream field parameters were measured; and multiple biological metrics were calculated. The experimental design to study the effects of fencing on the quality of near-stream shallow ground water involved a nested well approach. Two well nests were in the treatment basin, one each at surface-water sites T-1 and T-2. Within each well nest, the data from one deep well and three shallow wells (no greater than 12 ft deep) were used for regional characterization of ground-water quality. At each site, two of the shallow wells were inside the eventual fence (treated wells); the other shallow well was outside the eventual fence (control well). The wells were sampled monthly, primarily during periods with little to no recharge, for laboratory analysis of nutrients and fecal streptococcus; field parameters of water quality also were measured.

Paleobiological implications of dinosaur egg-bearing deposits in the Cretaceous Gyeongsang Supergroup of Korea

NASA Astrophysics Data System (ADS)

Paik, In Sung; Kim, Hyun Joo; Huh, Min

2010-05-01

Dinosaur egg-bearing deposits in the Cretaceous Gyeongsang Basin in Korea is described in taphonomic aspect, their paleoenvironments are interpreted, and geobiological implications of dinosaur egg-bearing deposits in the world and Korea are analyzed in geographic occurrences, geological ages, paleoenvironments, and lithology. Dinosaur eggs with spheroolithids, faveoloolithid, and elongatoolithid structural types occur in several stratigraphic formations of the Cretaceous Gyeongsang Basin in South Korea, and most of the egg-bearing formations are the Late Cretaceous. The dinosaur eggs usually occur as clutches in purple sandy mudstone of floodplain deposits preserved as calcic paleosol with association of vertic paleosol features in places. Most of the eggs are top-broken and filled with surrounding sediments. The general depositional environment of dinosaur egg deposits in the Gyeongsang Supergroup are interpreted as a dried floodplain where volcanic activity occurred intermittently in the vicinity of the nesting sites. Their depositional settings on which floodplains developed are diverse from fluvial plain with meandering rivers to alluvial plain with episodic sheet flooding. The nesting areas in the Gyeongsang Basin are deemed to have been under semi-arid climate, which resulted in formation of calcic soils facilitating preservation of the dinosaur eggs. The geochronologic occurrences of dinosaur egg-bearing deposits are mostly restricted to the Late Cretaceous in the world as well as in Korea. If it has not been resulted from biased discoveries and reports of dinosaur eggs, biological rather than physical and chemical conditions for preservation of dinosaur eggs might be related with the restricted occurrences in the Late Cretaceous. Two hypotheses are suggested for probable biological causes to the geochronologically restricted occurrences of dinosaur egg-bearing deposits. One is related with the appearance of angiosperms in the Late Jurassic and the spreading of angiosperm trees in ecological range through swamps and floodplains during the Late Cretaceous and subsequent change of herbivorous dinosaurs' dietary habit and the increase of volcanic activity in the Cretaceous. The other is related with the nesting behaviour in the Cretaceous. By contrast to the geochronologically restricted occurrence of dinosaur eggs, paleoenvironments of nesting areas of dinosaurs are varying from inland areas (alluvial fan, fluvial plain, desert, lake, etc.) to coastal areas (coastal plain, beach, lagoon), suggesting that dinosaurs avoided competition in sharing nesting areas. Little change in lithology from nested deposits to subsequent burying sediments indicates that dinosaurs preferred stable environment in terms of sedimentation as nesting sites. Key words: Dinosaur eggs, Cretaceous, Paleobiological occurrence, Korea

Minimizing yellow-bellied sapsucker damage

Treesearch

Gayne G. Erdmann; Ralph M., Jr. Peterson

1992-01-01

The yellow-bellied sapsucker is a migratory woodpecker that feeds on a wide variety of orchard, shade, and forest trees. Instead of drilling holes to find insects like other woodpeckers, sapsuckers drill holes in living trees to feed on sap and phloem tissues. Yellow and paper birches are their favorite summer food sources on their nesting grounds in Upper Michigan and...

PCBs and DDE in Tree Swallow (Tachycineta bicolor) Eggs and Nestlings from an Estuarine PCB Superfund Site, New Bedford Harbor, MA, U.S.A.

EPA Science Inventory

While breeding tree swallows (Tachycineta bicolor) have been used as biomonitors for freshwater sites, we report the first use of this species to assess the transfer of breeding ground contaminants from an estuarine system. Eggs and nestlings were collected from nest boxes locat...

Species-specific variation in nesting and postfledging resource selection for two forest breeding migrant songbirds

Treesearch

Julianna M. A. Jenkins; Frank R. Thompson; John Faaborg; Andrew J. Kroll

2017-01-01

Habitat selection is a fundamental component of community ecology, population ecology, and evolutionary biology and can be especially important to species with complex annual habitat requirements, such as migratory birds. Resource preferences on the breeding grounds may change during the postfledging period for migrant songbirds, however, the degree to which selection...

Food provisioning and parental status in songbirds: can occupancy models be used to estimate nesting performance?

PubMed

Corbani, Aude Catherine; Hachey, Marie-Hélène; Desrochers, André

2014-01-01

Indirect methods to estimate parental status, such as the observation of parental provisioning, have been problematic due to potential biases associated with imperfect detection. We developed a method to evaluate parental status based on a novel combination of parental provisioning observations and hierarchical modeling. In the summers of 2009 to 2011, we surveyed 393 sites, each on three to four consecutive days at Forêt Montmorency, Québec, Canada. We assessed parental status of 2331 adult songbirds based on parental food provisioning. To account for imperfect detection of parental status, we applied MacKenzie et al.'s (2002) two-state hierarchical model to obtain unbiased estimates of the proportion of sites with successfully nesting birds, and the proportion of adults with offspring. To obtain an independent evaluation of detection probability, we monitored 16 active nests in 2010 and conducted parental provisioning observations away from them. The probability of detecting food provisioning was 0.31 when using nest monitoring, a value within the 0.11 to 0.38 range that was estimated by two-state models. The proportion of adults or sites with broods approached 0.90 and varied depending on date during the sampling season and year, exemplifying the role of eastern boreal forests as highly productive nesting grounds for songbirds. This study offers a simple and effective sampling design for studying avian reproductive performance that could be implemented in national surveys such as breeding bird atlases.

Food Provisioning and Parental Status in Songbirds: Can Occupancy Models Be Used to Estimate Nesting Performance?

PubMed Central

Corbani, Aude Catherine; Hachey, Marie-Hélène; Desrochers, André

2014-01-01

Indirect methods to estimate parental status, such as the observation of parental provisioning, have been problematic due to potential biases associated with imperfect detection. We developed a method to evaluate parental status based on a novel combination of parental provisioning observations and hierarchical modeling. In the summers of 2009 to 2011, we surveyed 393 sites, each on three to four consecutive days at Forêt Montmorency, Québec, Canada. We assessed parental status of 2331 adult songbirds based on parental food provisioning. To account for imperfect detection of parental status, we applied MacKenzie et al.'s (2002) two-state hierarchical model to obtain unbiased estimates of the proportion of sites with successfully nesting birds, and the proportion of adults with offspring. To obtain an independent evaluation of detection probability, we monitored 16 active nests in 2010 and conducted parental provisioning observations away from them. The probability of detecting food provisioning was 0.31 when using nest monitoring, a value within the 0.11 to 0.38 range that was estimated by two-state models. The proportion of adults or sites with broods approached 0.90 and varied depending on date during the sampling season and year, exemplifying the role of eastern boreal forests as highly productive nesting grounds for songbirds. This study offers a simple and effective sampling design for studying avian reproductive performance that could be implemented in national surveys such as breeding bird atlases. PMID:24999969

Demographic differences of black-capped vireos in 2 habitat types in central Texas

USGS Publications Warehouse

Noa, L.A.; Hirth, D.H.; Donovan, T.M.; Cimprich, D.

2007-01-01

To understand the effects of habitat selection, we analyzed differences in abundance, age structure, and nesting success of black-capped vireos (Vireo atricapilla) in 2 early successional habitat types found on Fort Hood, a 87,890-ha Military Reservation in central Texas, USA. These habitats were 1) large areas of continuously shrubby vegetation (both natural and mechanically made), referred to as shrubland habitat, and 2) anthropogenically created small patches of shrubby vegetation centered on one or several large trees, known locally as donut habitat. The objectives of our study were to determine whether there were differences in abundance, age structure, and daily nest survival in these 2 habitat types and to determine whether donut habitat is high- or low-quality habitat. Donut habitat had a lower abundance of vireos (half as many as shrubland/point count) and a higher percentage of second-year males, suggesting donut habitat was lower-quality habitat than shrubland. Analyses of daily nest survival indicated that habitat, nest height, and year were all important variables. Nests initiated in 2004, located in shrubland habitats, and higher from the ground were more likely to succeed. Our study provided evidence that habitat is a limiting factor for this federally endangered species. Because habitat is limiting, wildlife biologists at Fort Hood should focus on managing higher quality, contiguous shrubland habitat. Wildlife biologists should also continue to monitor areas of donut habitat to determine whether they represent potential population sinks.

Agricultural management affects evolutionary processes in a migratory songbird

USGS Publications Warehouse

Perlut, N.G.; Freeman-Gallant, C. R.; Strong, A.M.; Donovan, T.M.; Kilpatrick, C.W.; Zalik, N.J.

2008-01-01

Hay harvests have detrimental ecological effects on breeding songbirds, as harvesting results in nest failure. Importantly, whether harvesting also affects evolutionary processes is not known. We explored how hay harvest affected social and genetic mating patterns, and thus, the overall opportunity for sexual selection and evolutionary processes for a ground-nesting songbird, the Savannah sparrow (Passerculus sandwichensis). On an unharvested field, 55% of females were in polygynous associations, and social polygyny was associated with greater rates of extra-pair paternity (EPP). In this treatment, synchrony explained variation in EPP rates, as broods by more synchronous females had more EPP than broods by asynchronous females. In contrast, on a harvested field, simultaneous nest failure caused by haying dramatically decreased the overall incidence of EPP by increasing the occurrence of social monogamy and, apparently, the ability of polygynous males to maintain paternity in their own nests. Despite increased social and genetic monogamy, these haying-mediated changes in mating systems resulted in greater than twofold increase in the opportunity for sexual selection. This effect arose, in part, from a 30% increase in the variance associated with within-pair fertilization success, relative to the unharvested field. This effect was caused by a notable increase (+110%) in variance associated with the quality of social mates following simultaneous nest failure. Because up to 40% of regional habitat is harvested by early June, these data may demonstrate a strong population-level effect on mating systems, sexual selection, and consequently, evolutionary processes. ?? 2008 The Authors.

Reduction in sea lamprey hatching success due to release of sterilized males

USGS Publications Warehouse

Bergstedt, Roger A.; McDonald, Rodney B.; Twohey, Michael B.; Mullett, Katherine M.; Young, Robert J.; Heinrich, John W.

2003-01-01

Male sea lampreys (Petromyzon marinus), sterilized by injection with bisazir, were released in Lake Superior tributaries from 1991 to 1996 and exclusively in the St. Marys River (the outflow from Lake Superior to Lake Huron) since 1997 as an alternative to chemical control. To determine effectiveness in reducing reproductive potential through the time of hatch, males were observed on nests and egg viability was determined in nests in selected Lake Superior tributaries and the St. Marys River. The proportions of sterilized males observed on nests were not significantly different than their estimated proportion in the population for all streams and years combined or for the St. Marys River alone. It was concluded that sterilized males survive, appear on the spawning grounds, and nest at near their estimated proportion in the population. There was a significant reduction in egg viability corresponding with release of sterilized males for all streams and years combined or for the St. Marys River alone. In the St. Marys River from 1993 to 2000, the percent reduction in egg viability was significantly correlated with the observed proportion of sterile males on nests. It was further concluded that sterilized males remain sterile through nesting and attract and mate with females. Reduction in reproductive potential in the St. Marys River due to both removal of females by traps and sterile-male-release ranged from 34 to 92% from 1993 to 2001 and averaged 64%. From 1999 to 2001, when the program stabilized, reductions ranged from 71 to 92% and averaged 81%. The current release of sterile males in the St. Marys River effectively reduced reproductive potential through the time of hatch and did so near theoretical levels based on numbers released, estimates of population size, and the assumptions of full sterility and competitiveness.

"Up" or "down" that makes the difference. How giant honeybees (Apis dorsata) see the world.

PubMed

Koeniger, Nikolaus; Kurze, Christoph; Phiancharoen, Mananya; Koeniger, Gudrun

2017-01-01

A. dorsata builds its large exposed comb high in trees or under ledges of high rocks. The "open" nest of A. dorsata, shielded (only!) by multiple layers of bees, is highly vulnerable to any kind of direct contact or close range attacks from predators. Therefore, guard bees of the outer layer of A. dorsata's nest monitor the vicinity for possible hazards and an effective risk assessment is required. Guard bees, however, are frequently exposed to different objects like leaves, twigs and other tree litter passing the nest from above and falling to the ground. Thus, downward movement of objects past the nest might be used by A. dorsata to classify these visual stimuli near the nest as "harmless". To test the effect of movement direction on defensive responses, we used circular black discs that were moved down or up in front of colonies and recorded the number of guard bees flying towards the disc. The size of the disc (diameter from 8 cm to 50 cm) had an effect on the number of guard bees responding, the bigger the plate the more bees started from the nest. The direction of a disc's movement had a dramatic effect on the attraction. We found a significantly higher number of attacks, when discs were moved upwards compared to downward movements (GLMM (estimate ± s.e.) 1.872 ± 0.149, P < 0.001). Our results demonstrate for the first time that the vertical direction of movement of an object can be important for releasing defensive behaviour. Upward movement of dark objects near the colony might be an innate releaser of attack flights. At the same time, downward movement is perceived as a "harmless" stimulus.

Experimental removal of woody vegetation does not increase nesting success or fledgling production in two grassland sparrows (Ammodramus) in Pennsylvania

USGS Publications Warehouse

Hill, Jason M.; Diefenbach, Duane R.

2013-01-01

The influence of vegetation structure on the probability of daily nest survival (DNS) for grassland passerines has received considerable attention. Some correlative studies suggest that the presence of woody vegetation lowers DNS. Over 3 years (2009–2011), we monitored 215 nests of the Grasshopper Sparrow (Ammodramus savannarum) and Henslow's Sparrow (A. henslowii) on 162 ha of reclaimed surface-mine grasslands in Pennsylvania. We removed shrubs from treatment plots with ≤36% areal coverage of woody vegetation in a before-after-control-impact-pairs (BACIP) design framework. Daily nest survival (95% CI: 0.94–0.96) was as high as previous studies have reported but was not associated with woody vegetative cover, proximity to woody vegetation, or woody stem density. Variation in DNS was best explained by increasing nonwoody-vegetation height. Grasshopper Sparrow fledgling production on treatment plots in 2010 (95% CI: 3.3–4.7) and 2011 (95% CI: 3.8–5.0) was similar to baseline conditions of treatment plots (95% CI: 3.4–4.9) and control plots (95% CI: 3.2–4.5) in 2009. Fledgling production was associated with thatch depth (β ± SE = 0.13 ± 0.09) and bare ground (β ± SE = -2.62 ± 1.29) adjacent to the nest and plot woody vegetative cover ( ± SE = -3.09 ± 1.02). Our experimental research suggests that overall reproductive success of Grasshopper and Henslow's sparrows on reclaimed surfacemine grasslands is driven by a suite of largely nonwoody—vegetation components, and both species can successfully nest and produce young in habitats with greater amounts of scattered woody vegetation than has generally been considered.

Nest site preference depends on the relative density of conspecifics and heterospecifics in wild birds.

PubMed

Samplonius, Jelmer M; Kromhout Van Der Meer, Iris M; Both, Christiaan

2017-01-01

Social learning allows animals to eavesdrop on ecologically relevant knowledge of competitors in their environment. This is especially important when selecting a habitat if individuals have relatively little personal information on habitat quality. It is known that birds can use both conspecific and heterospecific information for social learning, but little is known about the relative importance of each information type. If provided with the choice between them, we expected that animals should copy the behaviour of conspecifics, as these confer the best information for that species. We tested this hypothesis in the field for Pied Flycatchers Ficedula hypoleuca arriving at their breeding grounds to select a nest box for breeding. We assigned arbitrary symbols to nest boxes of breeding pied flycatchers (conspecifics) and blue and great tits, Cyanistes caeruleus and Parus major (heterospecifics), in 2014 and 2016 in two areas with different densities of tits and flycatchers. After ca 50% of flycatchers had returned and a flycatcher symbol was assigned to their nest box, we gave the later arriving flycatchers the choice between empty nest boxes with either a conspecific (flycatcher) or a heterospecific (tit) symbol. As expected, Pied Flycatchers copied the perceived nest box choice of conspecifics, but only in areas that were dominated by flycatchers. Against our initial expectation, flycatchers copied the perceived choice of heterospecifics in the area heavily dominated by tits, even though conspecific minority information was present. Our results confirm that the relative density of conspecifics and heterospecifics modulates the propensity to copy or reject novel behavioural traits. By contrasting conspecific and heterospecific ecology in the same study design we were able to draw more general conclusions about the role of fluctuating densities on social information use.

Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs.

PubMed

Lockley, Martin G; McCrea, Richard T; Buckley, Lisa G; Lim, Jong Deock; Matthews, Neffra A; Breithaupt, Brent H; Houck, Karen J; Gierliński, Gerard D; Surmik, Dawid; Kim, Kyung Soo; Xing, Lida; Kong, Dal Yong; Cart, Ken; Martin, Jason; Hadden, Glade

2016-01-07

Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of "display arenas" or leks, and consistent with "nest scrape display" behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred.

KSC-07pd0926

NASA Image and Video Library

2007-04-20

KENNEDY SPACE CENTER, FLA. -- This adult bald eagle rests on the ground near a pond close to S.R. 3 in NASA's Kennedy Space Center. Bald eagles live near large bodies of open water such as lakes, marshes, seacoasts and rivers, where there are plenty of fish to eat and tall trees for nesting and roosting. Bald eagles feed primarily on fish, but also eat small animals (ducks, coots, muskrats, turtles, rabbits, snakes, etc.) and occasional carrion (dead animals). They are sometimes seen among a gathering of vultures at the site of a fresh meal. Bald eagles have a presence in every U. S. state except Hawaii. Bald eagles use a specific territory for nesting (they mate for life), winter feeding or a year-round residence. Its natural domain is from Alaska to Baja, California, and from Maine to Florida. There are a dozen eagle nests both in KSC and in the Merritt Island National Wildlife Refuge, which surrounds KSC. The refuge includes several wading bird rookeries, many osprey nests, up to 400 manatees during the spring, and approximately 2,500 Florida scrub jays. It also is a major wintering area for migratory birds. More than 500 species of wildlife inhabit the refuge, with 15 considered federally threatened or endangered. Photo credit: NASA/George Shelton

KSC-07pd0925

NASA Image and Video Library

2007-04-20

KENNEDY SPACE CENTER, FLA. -- This adult bald eagle rests on the ground near a pond close to S.R. 3 in NASA's Kennedy Space Center. Bald eagles live near large bodies of open water such as lakes, marshes, seacoasts and rivers, where there are plenty of fish to eat and tall trees for nesting and roosting. Bald eagles feed primarily on fish, but also eat small animals (ducks, coots, muskrats, turtles, rabbits, snakes, etc.) and occasional carrion (dead animals). They are sometimes seen among a gathering of vultures at the site of a fresh meal. Bald eagles have a presence in every U. S. state except Hawaii. Bald eagles use a specific territory for nesting (they mate for life), winter feeding or a year-round residence. Its natural domain is from Alaska to Baja, California, and from Maine to Florida. There are a dozen eagle nests both in KSC and in the Merritt Island National Wildlife Refuge, which surrounds KSC. The refuge includes several wading bird rookeries, many osprey nests, up to 400 manatees during the spring, and approximately 2,500 Florida scrub jays. It also is a major wintering area for migratory birds. More than 500 species of wildlife inhabit the refuge, with 15 considered federally threatened or endangered. Photo credit: NASA/George Shelton

Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs

NASA Astrophysics Data System (ADS)

Lockley, Martin G.; McCrea, Richard T.; Buckley, Lisa G.; Deock Lim, Jong; Matthews, Neffra A.; Breithaupt, Brent H.; Houck, Karen J.; Gierliński, Gerard D.; Surmik, Dawid; Soo Kim, Kyung; Xing, Lida; Yong Kong, Dal; Cart, Ken; Martin, Jason; Hadden, Glade

2016-01-01

Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of “display arenas” or leks, and consistent with “nest scrape display” behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred.

Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs

PubMed Central

Lockley, Martin G.; McCrea, Richard T.; Buckley, Lisa G.; Deock Lim, Jong; Matthews, Neffra A.; Breithaupt, Brent H.; Houck, Karen J.; Gierliński, Gerard D.; Surmik, Dawid; Soo Kim, Kyung; Xing, Lida; Yong Kong, Dal; Cart, Ken; Martin, Jason; Hadden, Glade

2016-01-01

Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of “display arenas” or leks, and consistent with “nest scrape display” behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred. PMID:26741567

Ground water in the southeastern Uinta Basin, Utah and Colorado

USGS Publications Warehouse

Holmes, Walter F.; Kimball, Briant A.

1987-01-01

The potential for developing oil-shale resources in the southeastern Uinta Basin of Utah and Colorado has created the need for information on the quantity and quality of water available in the area. This report describes the availability and chemical quality of ground water, which might provide a source or supplement of water supply for an oil-shale industry. Ground water in the southeastern Uinta Basin occurs in three major aquifers. Alluvial aquifers of small areal extent are present i n val ley-f i 11 deposits of six major drainages. Consolidated-rock aquifers include the birds's-nest aquifer i n the Parachute Creek Member of the G reen River Formation, which is limited to the central part of the study area; and the Douglas Creek aquifer, which includes parts of the Douglas Creek Member of the Green River Formation and parts of the intertonguing Renegade Tongue of the Wasatch Formation; this aquifer underlies most of the study area.The alluvial aquifers are recharged by infiltration of streamflow and leakage from consolidated-rock aquifers. Recharge is estimated to average about 32,000 acre-feet per year. Discharge from alluvial aquifers, primarily by evapotranspiration, also averages about 32,000 acre-feet per year. The estimated volume of recoverable water in storage in alluvial aquifers is about 200,000 acre-feet. Maximum yields to individual wells are less than 1,000 gallons per minute.Recharge to the bird's-nest aquifer, primarily from stream infiltration and downward leakage from the overlying Uinta Formation, is estimated to average 670 acre-feet per year. Discharge from the bird's-nest aquifer, which is primarily by seepage to Bitter Creek and the White River, is estimated to be at 670 acre-feet per year. The estimated volume of recoverable water in storage in the bird's-nest aquifer is 1.9 million acre-feet. Maximum yields to individual wells in some areas may be as much as 5,000 gallons per minute. A digital-computer model of the flow system was used to evaluate the effects of oil-shale development on the bird's-nest aquifer at the Federal lease tracts Ua and Ub. Results of model simulations indicate that during construction of a vertical access shaft, a pumping rate of about 900 gallons per minute would be required to dewaterthe aquifer. The model also indicates that the construction of a proposed reservoir on the White River may raise water levels in the bird's-nest aquifer near the reservoir site by as much as 45 feet.The flow model was used to evaluate the potential ground-water supply available for oil-shale development in the vicinity of the Federal lease tracts Ua and Ub. The results of the simulation indicate that bird's-nest aquifer could supply about 10,000 acre-feet of water per year at that site, for a period of 20 years. Downdraw after 20 years of pumping would exceed 250 feet near the simulated well field. Based on the results of the model simulation, it is estimated that the aquifer could simultaneously supply another 10,000 acre-feet of water per year in the northern part of the study area, but some interference between well fields could be expected.The Douglas Creek aquifer is recharged by precipitation and stream infiltration at an average rate of about 20.000 acre-feet per year. Discharge is estimated to be about the same and is primarily through springs and diffuse seepage. The estimated volume of recoverable water in storage is 16 million acre-feet. Maximum yields to individual wells are estimated to be less than 500 gallons per minute.A model of the flow system in the Douglas Creek aquifer indicates that the aquifer could supply about 700 acre-feet of water per year for oil-shale development at Federal lease tracts Ua and Ub and at the TOSCO Corp. site. After 20 years of pumping, water levels in production wells would be near the base of the aquifer. Based on the results of the model simulation, it is estimated that the aquifer could supply another 700 acre-feet of water per year in the southern part of the modeled area, but some interference between wells could be expected. Chemical quality of the ground water in the southeastern Uinta Basin varies considerably. Water from alluvial wells ranges from about 440 to 27,800 milligrams per liter of dissolved solids. Water from two consolidated-rock aquifers has dissolved-solids concentrations ranging from 870 to 5,810 milligrams per liter in the bird's-nest aquifer, and from 640 to 6,100 milligrams per liter in the Douglas Creek aquifer. Water from alluvial wells generally is a sodium sulfate type, whereas water in both the consolidated-rock aquifers generally changes from a sodium sulfate type to a sodium bicarbonate type. All ground water is very alkaline, and the alluvial aquifers contain very hard water. None of the water is suitable for public supply, but all the water could be used for industrial purposes such as washing and cooling.Changes in chemical composition of the ground water can be attributed to several physiochemical processes, including mineral precipitation and dissolution, oxidation and reduction, mixing, ion exchange, and evaporative concentration. Mass-transfer modeling of these processes shows how they can account for the variability in the ground-water quality. The mass-transfer model of the Bitter Creek alluvial aquifer shows that evaporative concentration, combined with precipitation of calcite, dolomite, gypsum, and release of carbon dioxide to the atmosphere results in the documented changes in the pH and dissolved solids in the water. The water-quality changes in the consolidated-rock aquifers are a result of precipitation of calcium carbonate and perhaps dolomite (calcium magnesium carbonate) with the reduction of sulfate by organic carbon, as well as ion exchange of magnesium for sodium. These processes result in large values of pH and alkalinity in the water.

Association between nighttime artificial light pollution and sea turtle nest density along Florida coast: A geospatial study using VIIRS remote sensing data.

PubMed

Hu, Zhiyong; Hu, Hongda; Huang, Yuxia

2018-08-01

Artificial lighting at night has becoming a new type of pollution posing an important anthropogenic environmental pressure on organisms. The objective of this research was to examine the potential association between nighttime artificial light pollution and nest densities of the three main sea turtle species along Florida beaches, including green turtles, loggerheads, and leatherbacks. Sea turtle survey data was obtained from the "Florida Statewide Nesting Beach Survey program". We used the new generation of satellite sensor "Visible Infrared Imaging Radiometer Suite (VIIRS)" (version 1 D/N Band) nighttime annual average radiance composite image data. We defined light pollution as artificial light brightness greater than 10% of the natural sky brightness above 45° of elevation (>1.14 × 10 -11 Wm -2 sr -1 ). We fitted a generalized linear model (GLM), a GLM with eigenvectors spatial filtering (GLM-ESF), and a generalized estimating equations (GEE) approach for each species to examine the potential correlation of nest density with light pollution. Our models are robust and reliable in terms of the ability to deal with data distribution and spatial autocorrelation (SA) issues violating model assumptions. All three models found that nest density is significantly negatively correlated with light pollution for each sea turtle species: the higher light pollution, the lower nest density. The two spatially extended models (GLM-ESF and GEE) show that light pollution influences nest density in a descending order from green turtles, to loggerheads, and then to leatherbacks. The research findings have an implication for sea turtle conservation policy and ordinance making. Near-coastal lights-out ordinances and other approaches to shield lights can protect sea turtles and their nests. The VIIRS DNB light data, having significant improvements over comparable data by its predecessor, the DMSP-OLS, shows promise for continued and improved research about ecological effects of artificial light pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Parentage of overlapping offspring of an arboreal-breeding frog with no nest defense: implications for nest site selection and reproductive strategy.

PubMed

Tung, Wan-Ping; Chen, Yi-Huey; Cheng, Wei-Chun; Chuang, Ming-Feng; Hsu, Wan-Tso; Kam, Yeong-Choy; Lehtinen, Richard M

2015-01-01

Overlapping offspring occurs when eggs are laid in a nest containing offspring from earlier reproduction. Earlier studies showed that the parentage is not always obvious due to difficulties in field observation and/or alternative breeding tactics. To unveil the parentage between overlapping offspring and parents is critical in understanding oviposition site selection and the reproductive strategies of parents. Amplectant pairs of an arboreal-breeding frog, Kurixalus eiffingeri, lay eggs in tadpole-occupied nests where offspring of different life stages (embryos and tadpoles) coexist. We used five microsatellite DNA markers to assess the parentage between parents and overlapping offspring. We also tested the hypothesis that the male or female frog would breed in the same breeding site because of the scarcity of nest sites. Results showed varied parentage patterns, which may differ from the phenomenon of overlapping egg clutches reported earlier. Parentage analyses showed that only 58 and 25% of the tadpole-occupied stumps were reused by the same male and female respectively, partially confirming our prediction. Re-nesting by the same individual was more common in males than females, which is most likely related to the cost of tadpole feeding and/or feeding schemes of females. On the other hand, results of parentage analyses showed that about 42 and 75% of male and female respectively bred in tadpole-occupied stumps where tadpoles were genetically unrelated. Results of a nest-choice experiment revealed that 40% of frogs chose tadpole-occupied bamboo cups when we presented identical stumps, without or with tadpoles, suggesting that the habitat saturation hypothesis does not fully explain why frogs used the tadpole-occupied stumps. Several possible benefits of overlapping offspring with different life stages were proposed. Our study highlights the importance of integrating molecular data with field observations to better understand the reproductive biology and nest site selection of anuran amphibians.

Hydraulic properties of three types of glacial deposits in Ohio

USGS Publications Warehouse

Strobel, M.L.

1993-01-01

The effects of thickness, grain size, fractures, weathering, and atmosphericconditions on vertical ground-water flow in glacial deposits were studied at three sites that represent ground moraine, end moraine, and lacustrine depositional environments. Vertical hydraulic conductivities computed from pumped-well tests were 3.24 x 10-1 to 6.47 x 10-1 ft/d (feet per day) at the site representing end moraine and 1.17 ft/d at the site representing lacustrine deposits. Analysis of test data for the ground moraine site did not yield estimates of hydraulic conductivities, but did indicate that ground water flows through the total thickness of deposits in response to discharge from a lower gravel unit. Vertical hydraulic conductivities computed from pumped-well tests of nested wells and data from drill-core analyses indicate that fractures affect the migration of ground water downward through the glacial deposits at these sites. Flow through glacial deposits is complex; it is controlled by fractures, gram-size distribution, clay content, thickness, and degree of weathering, and atmospheric conditions.

Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada

PubMed Central

Longstaffe, Fred J.; Zazula, Grant

2018-01-01

A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ13C and δ15N for vegetation and bone collagen and structural carbonate of some modern, Yukon, arctic ground squirrels with vegetation and bones from Late Pleistocene fossil arctic ground squirrel nests preserved in Yukon loess deposits. The isotopic discrimination between arctic ground squirrel bone collagen and their diet was measured using modern samples, as were isotopic changes during plant decomposition; Over-wintering decomposition of typical vegetation following senescence resulted in a minor change (~0–1 ‰) in δ13C of modern Yukon grasses. A major change (~2–10 ‰) in δ15N was measured for decomposing Yukon grasses thinly covered by loess. As expected, the collagen-diet C-isotope discrimination measured for modern samples confirms that modern vegetation δ13C is a suitable proxy for the Late Pleistocene vegetation in Yukon Territory, after correction for the Suess effect. The N-isotope composition of vegetation from the fossil arctic ground squirrel nests, however, is determined to be ~2.8 ‰ higher than modern grasslands in the region, after correction for decomposition effects. This result suggests a change in N dynamics in this region between the Late Pleistocene and modern time. PMID:29447202

Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada.

PubMed

Tahmasebi, Farnoush; Longstaffe, Fred J; Zazula, Grant

2018-01-01

A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ13C and δ15N for vegetation and bone collagen and structural carbonate of some modern, Yukon, arctic ground squirrels with vegetation and bones from Late Pleistocene fossil arctic ground squirrel nests preserved in Yukon loess deposits. The isotopic discrimination between arctic ground squirrel bone collagen and their diet was measured using modern samples, as were isotopic changes during plant decomposition; Over-wintering decomposition of typical vegetation following senescence resulted in a minor change (~0-1 ‰) in δ13C of modern Yukon grasses. A major change (~2-10 ‰) in δ15N was measured for decomposing Yukon grasses thinly covered by loess. As expected, the collagen-diet C-isotope discrimination measured for modern samples confirms that modern vegetation δ13C is a suitable proxy for the Late Pleistocene vegetation in Yukon Territory, after correction for the Suess effect. The N-isotope composition of vegetation from the fossil arctic ground squirrel nests, however, is determined to be ~2.8 ‰ higher than modern grasslands in the region, after correction for decomposition effects. This result suggests a change in N dynamics in this region between the Late Pleistocene and modern time.

Bird populations in logged and unlogged western larch/Douglas-fir forest in northwestern Montana

Treesearch

Bret W. Tobalske; Raymond C. Shearer; Richard L. Hutto

1991-01-01

Of 32 species of abundant breeding birds, populations of 10 species differed significantly between small cutting units and adjacent uncut forest. Foliage foragers and tree gleaners were less abundant in cutting units, while flycatching species and ground foragers were more common there. Of nesting guilds, conifer tree nesters were least abundant in cutting units, and...

Escape Distance in Ground-Nesting Birds Differs with Individual Level of Camouflage.

PubMed

Wilson-Aggarwal, Jared K; Troscianko, Jolyon T; Stevens, Martin; Spottiswoode, Claire N

2016-08-01

Camouflage is one of the most widespread antipredator strategies in the animal kingdom, yet no animal can match its background perfectly in a complex environment. Therefore, selection should favor individuals that use information on how effective their camouflage is in their immediate habitat when responding to an approaching threat. In a field study of African ground-nesting birds (plovers, coursers, and nightjars), we tested the hypothesis that individuals adaptively modulate their escape behavior in relation to their degree of background matching. We used digital imaging and models of predator vision to quantify differences in color, luminance, and pattern between eggs and their background, as well as the plumage of incubating adult nightjars. We found that plovers and coursers showed greater escape distances when their eggs were a poorer pattern match to the background. Nightjars sit on their eggs until a potential threat is nearby, and, correspondingly, they showed greater escape distances when the pattern and color match of the incubating adult's plumage-rather than its eggs-was a poorer match to the background. Finally, escape distances were shorter in the middle of the day, suggesting that escape behavior is mediated by both camouflage and thermoregulation.

Reproduction, mortality, and heavy metal concentrations in great blue herons from three colonies in Washington and Idaho

USGS Publications Warehouse

Blus, L.J.; Henny, C.J.; Anderson, A.; Fitzner, R.E.

1985-01-01

We collected eggs in nests, hatchlings and eggs with advanced embryos on the ground, and prefledgling young of Great Blue Herons (Ardea herodias) at three nesting colonies in Washington and Idaho. Intact fish were also collected on the ground at the Idaho colony. The Ft. Lewis colony near Puget Sound in Washington and the Lake Chatcolet colony in northern Idaho were located near areas extensively polluted with heavy metals from minning or smelting activities. The Hanford Reservation colony near Richland, Washington was located some distance from point sources of heavy metal pollution. Heavy metals in heron samples were generally low and were all below concentrations known to induce mortality or adversely affect reproductive success. The elevated copper in one of three prefledglings from Ft. Lewis paralleled that found in an occasional nestling of several species of birds in other studies; the significance of this relationship is unclear. Breeding herons apparently fed near their colonies in areas removed from the sites of heaviest contamination, but birds in the Lake Chatcolet colony were preying on fish containing as much as 6 mu-g/g lead.

Videographic evidence of endangered species depredation by feral cat

USGS Publications Warehouse

Judge, Seth; Lippert, Jill S.; Misajon, Kathleen; Hu, Darcy; Hess, Steven C.

2012-01-01

Feral cats (Felis cafus) have long been implicated as nest predators of endangered 'Ua'u (Hawaiian Petrel; Pterodroma sandwichensis) on Hawaii Island, but until recently, visual confirmation has been limited by available technology. 'Ua'u nest out of view, deep inside small cavities, on alpine lava flows. During the breeding seasons of 2007 and 2008, we monitored known burrows within Hawai'i Volcanoes National Park. Digital infrared video cameras assisted in determining the breeding behaviour and nesting success at the most isolated of burrows. With 7 cameras, we collected a total of 819 videos and 89 still photographs of adult and nestling 'Ua'u at 14 burrows. Videos also confirmed the presence of rats (Rattus spp.) at 2 burrows, 'Ōmao (Myadestes obscurus) at 8 burrows, and feral cats at 6 burrows. A sequence of videos showed a feral cat taking a downy 'Ua'u chick from its burrow, representing the first direct evidence of 'Ua'u depredation by feral cat in Hawai'i. This technique provides greater understanding of feral cat behaviour in 'Ua'u colonies, which may assist in the development of more targeted management strategies to reduce nest predation on endangered insular bird species.

Inferential reasoning and egg rejection in a cooperatively breeding cuckoo.

PubMed

Riehl, Christina; Strong, Meghan J; Edwards, Scott V

2015-01-01

Inferential reasoning-associating a visible consequence with an imagined event-has been demonstrated in several bird species in captivity, but few studies have tested wild birds in ecologically relevant contexts. Here, we investigate inferential reasoning by the greater ani, a cooperatively breeding cuckoo in which several females lay eggs in one nest. Prior to laying her first egg, each female removes any eggs that have already been laid by other females in the shared nest. After laying her first egg, however, each female stops removing eggs, presumably in order to avoid accidentally rejecting her own. But are anis using inferential reasoning to track the fate of their eggs in the communal nest, or is egg ejection governed by non-cognitive determinants? We experimentally removed eggs from two-female nests after both females had laid at least one egg and used video recording to verify that both females viewed the empty nest. We waited until one female (A) laid an egg in the nest, and video recorded the behavior of the female that had not yet re-laid (B). We predicted that if capable of inferential reasoning, female B should infer that the new egg could not be her own and she should remove it. Five out of five females tested failed to make this inference, suggesting that egg removal is either determined by the female's reproductive status or by the amount of time elapsed between egg removal and re-laying. This apparent cognitive constraint may have implications for the evolutionary stability of the anis' unusual breeding system.

Toxic elements and associations with hematology, plasma biochemistry, and protein electrophoresis in nesting loggerhead sea turtles (Caretta caretta) from Casey Key, Florida.

PubMed

Perrault, Justin R; Stacy, Nicole I; Lehner, Andreas F; Poor, Savannah K; Buchweitz, John P; Walsh, Catherine J

2017-12-01

Toxic elements (arsenic, cadmium, lead, mercury, selenium, thallium) are a group of contaminants that are known to elicit developmental, reproductive, general health, and immune system effects in reptiles, even at low concentrations. Reptiles, including marine turtles, are susceptible to accumulation of toxic elements due to their long life span, low metabolic rate, and highly efficient conversion of prey into biomass. The objectives of this study were to (1) document concentrations of arsenic, cadmium, lead, mercury, selenium, and thallium in whole blood and keratin from nesting loggerhead sea turtles (Caretta caretta) from Casey Key, Florida and document correlations thereof and (2) correlate whole blood toxic element concentrations to various hematological and plasma biochemistry analytes. Baselines for various hematological and plasma analytes and toxic elements in whole blood and keratin (i.e., scute) in nesting loggerheads are documented. Various correlations between the toxic elements and hematological and plasma biochemistry analytes were identified; however, the most intriguing were negative correlations between arsenic, cadmium, lead, and selenium with and α- and γ-globulins. Although various extrinsic and intrinsic variables such as dietary and feeding changes in nesting loggerheads need to be considered, this finding may suggest a link to altered humoral immunity. This study documents a suite of health variables of nesting loggerheads in correlation to contaminants and identifies the potential of toxic elements to impact the overall health of nesting turtles, thus presenting important implications for the conservation and management of this species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multinational tagging efforts illustrate regional scale of distribution and threats for east pacific green turtles (Chelonia mydas agassizii).

PubMed

Hart, Catherine E; Blanco, Gabriela S; Coyne, Michael S; Delgado-Trejo, Carlos; Godley, Brendan J; Jones, T Todd; Resendiz, Antonio; Seminoff, Jeffrey A; Witt, Matthew J; Nichols, Wallace J

2015-01-01

To further describe movement patterns and distribution of East Pacific green turtles (Chelonia mydas agassizii) and to determine threat levels for this species within the Eastern Pacific. In order to do this we combined published data from existing flipper tagging and early satellite tracking studies with data from an additional 12 satellite tracked green turtles (1996-2006). Three of these were tracked from their foraging grounds in the Gulf of California along the east coast of the Baja California peninsula to their breeding grounds in Michoacán (1337-2928 km). In addition, three post-nesting females were satellite tracked from Colola beach, Michoacán to their foraging grounds in southern Mexico and Central America (941.3-3020 km). A further six turtles were tracked in the Gulf of California within their foraging grounds giving insights into the scale of ranging behaviour. Turtles undertaking long-distance migrations showed a tendency to follow the coastline. Turtles tracked within foraging grounds showed that foraging individuals typically ranged up to 691.6 km (maximum) from release site location. Additionally, we carried out threat analysis (using the cumulative global human impact in the Eastern Pacific) clustering pre-existing satellite tracking studies from Galapagos, Costa Rica, and data obtained from this study; this indicated that turtles foraging and nesting in Central American waters are subject to the highest anthropogenic impact. Considering that turtles from all three rookeries were found to migrate towards Central America, it is highly important to implement conservation plans in Central American coastal areas to ensure the survival of the remaining green turtles in the Eastern Pacific. Finally, by combining satellite tracking data from this and previous studies, and data of tag returns we created the best available distributional patterns for this particular sea turtle species, which emphasized that conservation measures in key areas may have positive consequences on a regional scale.

Multinational Tagging Efforts Illustrate Regional Scale of Distribution and Threats for East Pacific Green Turtles (Chelonia mydas agassizii)

PubMed Central

Hart, Catherine E.; Blanco, Gabriela S.; Coyne, Michael S.; Delgado-Trejo, Carlos; Godley, Brendan J.; Jones, T. Todd; Resendiz, Antonio; Seminoff, Jeffrey A.; Witt, Matthew J.; Nichols, Wallace J.

2015-01-01

To further describe movement patterns and distribution of East Pacific green turtles (Chelonia mydas agassizii) and to determine threat levels for this species within the Eastern Pacific. In order to do this we combined published data from existing flipper tagging and early satellite tracking studies with data from an additional 12 satellite tracked green turtles (1996-2006). Three of these were tracked from their foraging grounds in the Gulf of California along the east coast of the Baja California peninsula to their breeding grounds in Michoacán (1337-2928 km). In addition, three post-nesting females were satellite tracked from Colola beach, Michoacán to their foraging grounds in southern Mexico and Central America (941.3-3020 km). A further six turtles were tracked in the Gulf of California within their foraging grounds giving insights into the scale of ranging behaviour. Turtles undertaking long-distance migrations showed a tendency to follow the coastline. Turtles tracked within foraging grounds showed that foraging individuals typically ranged up to 691.6 km (maximum) from release site location. Additionally, we carried out threat analysis (using the cumulative global human impact in the Eastern Pacific) clustering pre-existing satellite tracking studies from Galapagos, Costa Rica, and data obtained from this study; this indicated that turtles foraging and nesting in Central American waters are subject to the highest anthropogenic impact. Considering that turtles from all three rookeries were found to migrate towards Central America, it is highly important to implement conservation plans in Central American coastal areas to ensure the survival of the remaining green turtles in the Eastern Pacific. Finally, by combining satellite tracking data from this and previous studies, and data of tag returns we created the best available distributional patterns for this particular sea turtle species, which emphasized that conservation measures in key areas may have positive consequences on a regional scale. PMID:25646803

Small and large wetland fragments are equally suited breeding sites for a ground-nesting passerine.

PubMed

Pasinelli, Gilberto; Mayer, Christian; Gouskov, Alexandre; Schiegg, Karin

2008-06-01

Large habitat fragments are generally thought to host more species and to offer more diverse and/or better quality habitats than small fragments. However, the importance of small fragments for population dynamics in general and for reproductive performance in particular is highly controversial. Using an information-theoretic approach, we examined reproductive performance and probability of local recruitment of color-banded reed buntings Emberiza schoeniclus in relation to the size of 18 wetland fragments in northeastern Switzerland over 4 years. We also investigated if reproductive performance and recruitment probability were density-dependent. None of the four measures of reproductive performance (laying date, nest failure probability, fledgling production per territory, fledgling condition) nor recruitment probability were found to be related to wetland fragment size. In terms of fledgling production, however, fragment size interacted with year, indicating that small fragments were better reproductive grounds in some years than large fragments. Reproductive performance and recruitment probability were not density-dependent. Our results suggest that small fragments are equally suited as breeding grounds for the reed bunting as large fragments and should therefore be managed to provide a habitat for this and other specialists occurring in the same habitat. Moreover, large fragments may represent sinks in specific years because a substantial percentage of all breeding pairs in our study area breed in large fragments, and reproductive failure in these fragments due to the regularly occurring floods may have a much stronger impact on regional population dynamics than comparable events in small fragments.

Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation

USDA-ARS?s Scientific Manuscript database

Recent reports of global declines in pollinator species imply an urgent need to assess native pollinator population sizes and density dependent benefits for linked plants. Here, we estimated effective population sizes (Ne) of four native bumblebee species, Bombus balteatus, B. flavifrons, B. bifariu...

Numbers and distribution of Double-crested Cormorants on the upper Mississippi river

USGS Publications Warehouse

Kirsch, E.M.

1997-01-01

Historic records indicate that Double-crested Cormorants (Phalacrocorax auritus) were common breeders and abundant during migration on the Upper Mississippi River from St. Paul, Minnesota, to St. Louis, Missouri, during the 1940s and 1950s. Their numbers declined in the mid- to late-1950s, remained low through the 1970s, and began to increase somewhat in the late 1980s. Aerial surveys of migrating cormorants and ground surveys at cormorant colonies during 1991-1993, indicate that numbers have not returned to historic levels. Only 500-2,000 cormorants were seen during spring migration 1992-1993; and 5,000-7,000 during fall migration 1991-1992; whereas, tens of thousands were reported in the 1940s and 1950s. Four hundred ninety-six nests were counted at 4 colonies in 1992, and 545 nests were counted in 9 colonies in 1993; whereas, during the 1940s and 1950s, about 2,500 birds were reported nesting in 4 locations. Pools 6 and 13 have always attracted breeding and migrating cormorants, currently attract the largest numbers of cormorants during migration, and still support breeding colonies.

Numbers and distribution of double-crested cormorants on the upper Mississippi River

USGS Publications Warehouse

Kirsch, E.M.

1997-01-01

Historic records indicate that Double-crested Cormorants (Phalacrocorax auritus) were common breeders and abundant during migration on the Upper Mississippi River from St. Paul, Minnesota, to St. Louis, Missouri, during the 1940s and 1950s. Their numbers declined in the mid-to late-1950s, remained low through the 1970s, and began to increase somewhat in the late 1980s. Aerial surveys of migrating cormorants and ground surveys at cormorant colonies during 1991-1993, indicate that numbers have not returned to historic levels. Only 500-2,000 cormorants were seen during spring migration 1992-1993; and 5,000-7,000 during fall migration 1991-1992; whereas, tens of thousands were reported in the 1940s and 1950s. Four hundred ninety-six nests were counted at 4 colonies in 1992, and 545 nests were counted in 9 colonies in 1993; whereas, during the 1940s and 1950s, about 2,500 birds were reported nesting in 4 locations. Pools 6 and 13 have always attracted breeding and migrating cormorants, currently attract the largest numbers of cormorants during migration, and still support breeding colonies.

Conventional oil and natural gas infrastructure increases brown-headed cowbird (Molothrus ater) relative abundance and parasitism in mixed-grass prairie.

PubMed

Bernath-Plaisted, Jacy; Nenninger, Heather; Koper, Nicola

2017-07-01

The rapid expansion of oil and natural gas development across the Northern Great Plains has contributed to habitat fragmentation, which may facilitate brood parasitism of ground-nesting grassland songbird nests by brown-headed cowbirds ( Molothrus ater ), an obligate brood parasite, through the introduction of perches and anthropogenic edges. We tested this hypothesis by measuring brown-headed cowbird relative abundance and brood parasitism rates of Savannah sparrow ( Passerculus sandwichensis ) nests in relation to the presence of infrastructure features and proximity to potential perches and edge habitat. The presence of oil and natural gas infrastructure increased brown-headed cowbird relative abundance by a magnitude of four times, which resulted in four times greater brood parasitism rates at infrastructure sites. While the presence of infrastructure and the proximity to roads were influential in predicting brood parasitism rates, the proximity of perch sites was not. This suggests that brood parasitism associated with oil and natural gas infrastructure may result in additional pressures that reduce productivity of this declining grassland songbird.

Conventional oil and natural gas infrastructure increases brown-headed cowbird (Molothrus ater) relative abundance and parasitism in mixed-grass prairie

PubMed Central

Nenninger, Heather; Koper, Nicola

2017-01-01

The rapid expansion of oil and natural gas development across the Northern Great Plains has contributed to habitat fragmentation, which may facilitate brood parasitism of ground-nesting grassland songbird nests by brown-headed cowbirds (Molothrus ater), an obligate brood parasite, through the introduction of perches and anthropogenic edges. We tested this hypothesis by measuring brown-headed cowbird relative abundance and brood parasitism rates of Savannah sparrow (Passerculus sandwichensis) nests in relation to the presence of infrastructure features and proximity to potential perches and edge habitat. The presence of oil and natural gas infrastructure increased brown-headed cowbird relative abundance by a magnitude of four times, which resulted in four times greater brood parasitism rates at infrastructure sites. While the presence of infrastructure and the proximity to roads were influential in predicting brood parasitism rates, the proximity of perch sites was not. This suggests that brood parasitism associated with oil and natural gas infrastructure may result in additional pressures that reduce productivity of this declining grassland songbird. PMID:28791134

KSC-2009-1513

NASA Image and Video Library

2009-01-31

CAPE CANAVERAL, Fla. – Near the NASA News Center at NASA's Kennedy Space Center in Florida, the osprey prepares to land on a pole with its meal in its talons. The osprey, also called fish hawk, is well adapted for capturing fish, which make up its entire diet. The soles of the birds' feet are equipped with sharp, spiny projections that give the bird a firm grip on its slippery prey. Nests of ospreys are bulky masses of sticks and debris placed in a tree, on rocks, flat ground or telephone poles. Many nests exist around the Launch Complex 39 Area at the center. The bird is one of more than 500 species of birds that co-exist at the center and the surrounding Merritt Island National Wildlife Refuge. Photo credit: NASA/Ben Smelgelsky

Breeding bird response to juniper woodland expansion

USGS Publications Warehouse

Rosenstock, Steven S.; van Riper, Charles

2001-01-01

In recent times, pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands have expanded into large portions of the Southwest historically occupied by grassland vegetation. From 1997-1998, we studied responses of breeding birds to one-seed juniper (J. monosperma) woodland expansion at 2 grassland study areas in northern Arizona. We sampled breeding birds in 3 successional stages along a grassland-woodland gradient: un-invaded grassland, grassland undergoing early stages of juniper establishment, and developing woodland. Species composition varied greatly among successional stages and was most different between endpoints of the gradient. Ground-nesting grassland species predominated in uninvaded grassland but declined dramatically as tree density increased. Tree- and cavity-nesting species increased with tree density and were most abundant in developing woodland. Restoration of juniper-invaded grasslands will benefit grassland-obligate birds and other wildlife.

The role of nutrient reserves in mallard reproduction

USGS Publications Warehouse

Krapu, Gary L.

1981-01-01

Mallard (Anas platyrhynchos) populations breeding in temperate North America obtain a significant part of the energy and lipid requirements of reproduction at sites occupied prior to arrival on the breeding grounds. Protein for egg formation, however, is obtained principally from the diet during the nesting period. Both sexes arrive heavy and fat in North Dakota but experience substantial weight loss and lipid depletion during the nesting cycle. Weight loss is most pronounced among females and averages 25% from prelaying to late incubation. Body weights of both sexes are positively correlated with carcass lipid content. The paired male draws upon lipids early in the nesting season when an activity center is being established and defended and when females are preparing to nest. The female's lipid reserves are utilized primarily during laying and early incubation. The significance of lipid reserves diminishes as the nesting season progresses, and females do not acquire substantial lipid stores prior to renesting when the initial clutch is destroyed. The magnitude of lipid reserves carried in female carcasses is positively correlated with clutch size from mid-April to early June. Protein transfer for egg formation from flight and leg muscle and body organs can account for only a small part of the protein requirement for the clutch. By utilizing lipid reserves to meet energy requirements, the female can acquire sufficient protein from the diet to produce a large initial clutch even when foods are relatively scarce, whereas the renesting female must rely entirely upon food resources available at the breeding site for its nutrient and energy requirements.

Suicide by people in a community justice pathway: population-based nested case–control study

PubMed Central

King, Carlene; Senior, Jane; Webb, Roger T.; Millar, Tim; Piper, Mary; Pearsall, Alison; Humber, Naomi; Appleby, Louis; Shaw, Jenny

2015-01-01

The elevated risk of suicide in prison and after release is a well-recognised and serious problem. Despite this, evidence concerning community-based offenders' suicide risk is sparse. We conducted a population-based nested case–control study of all people in a community justice pathway in England and Wales. Our data show 13% of general population suicides were in community justice pathways before death. Suicide risks were highest among individuals receiving police cautions, and those having recent, or impending prosecution for sexual offences. Findings have implications for the training and practice of clinicians identifying and assessing suicidality, and offering support to those at elevated risk. PMID:26159602

Evaluating the efficacy of a landscape scale feral cat control program using camera traps and occupancy models.

PubMed

Comer, Sarah; Speldewinde, Peter; Tiller, Cameron; Clausen, Lucy; Pinder, Jeff; Cowen, Saul; Algar, Dave

2018-03-28

The impact of introduced predators is a major factor limiting survivorship and recruitment of many native Australian species. In particular, the feral cat and red fox have been implicated in range reductions and population declines of many conservation dependent species across Australia, including ground-nesting birds and small to medium-sized mammals. The impact of predation by feral cats since their introduction some 200 years ago has altered the structure of native fauna communities and led to the development of landscape-scale threat abatement via baiting programs with the feral cat bait, Eradicat. Demonstrating the effectiveness of broad-scale programs is essential for managers to fine tune delivery and timing of baiting. Efficacy of feral cat baiting at the Fortescue Marsh in the Pilbara, Western Australia was tested using camera traps and occupancy models. There was a significant decrease in probability of site occupancy in baited sites in each of the five years of this study, demonstrating both the effectiveness of aerial baiting for landscape-scale removal of feral cats, and the validity of camera trap monitoring techniques for detecting changes in feral cat occupancy during a five-year baiting program.

Comparison of the chemical compositions of the cuticle and the Dufour's gland of two solitary bee species from laboratory and field conditions

USDA-ARS?s Scientific Manuscript database

The biochemistry, morphology, and function of the Dufour’s glands have been investigated for social bees and some non-social bee families. This is a gland associated with the female bee stinger but does not deliver any poison. Most of the solitary bees examined previously are ground-nesting bees t...

Interspecific differences in hematozoan infection in Sonoran desert Aimophila sparrows.

PubMed

Deviche, Pierre; McGraw, Kevin; Greiner, Ellis C

2005-07-01

Numerous studies have identified factors that control avian hematozoan infections, but the mechanisms that account for host differences in parasitemia remain largely speculative. To address this issue, we compared the prevalence of these parasites in stained blood smears from four conspecific Sonoran desert Aimophila sparrow species sampled during their breeding season: rufous-winged (Aimophila carpalis; RWSP), rufous-crowned (Aimophila ruficeps; RCSP), Cassin's (Aimophila cassinii, CASP), and Botteri's (Aimophila botterii; BOSP) sparrows. Blood smears contained Haemoproteus fringillae (RWSP), Trypanosoma everetti (RWSP, RCSP, BOSP), Trypanosoma avium (CASP), and microfilariae (all species). Most (92.5%) RWSP (n=40) were infected with Haemoproteus, but this parasite was not detected in RCSP (n=20) or BOSP (n=20) and was found only in one (2.5%) CASP (n=40). Trypanosoma spp. and microfilariae were detected in all species, but prevalence differed between these four sparrow species. Species differences in parasite prevalence were not due to difference in sex, age, adult body mass, incubation period, breeding habitat, or plumage colorfulness. However, differences in Haemoproteus sp. prevalence correlated with preferred nesting height, as RWSP generally nest above ground, whereas the other species nest on or close to the ground. Elevated H. fringillae prevalence in breeding-condition RWSP presumably does not result from a seasonal relapse associated with breeding or require new infection because 1) this prevalence did not differ in males sampled during and outside (n=21) the breeding season, and 2) all male RWSP (n=25) that we held in captivity and shielded from new infections and influence of natural photoperiod for 1 yr had viable blood H. fringillae gametocytes. H. fringillae prevalence in fall-sampled hatch-year male RWSP (n=11) was 63.6%, demonstrating that this parasite can be transmitted on the breeding grounds and during the first months of life. T. everetti prevalence in RWSP was lower in winter than in summer and also in long-term captive than in free-ranging adults. Presence of this parasite in the blood of breeding males may depend on recrudescence of existing infections or new infections.

Observations on distribution, diet, and breeding of the Hawaiian thrush

USGS Publications Warehouse

van Riper, Charles; Scott, J. Michael

1979-01-01

Distribution, breeding habits, and diet of the Hawaiian Thrush were recorded over seven years on the island of Hawaii. The range has been much reduced, with the result that today the species occupies approximately 30% of its former range, no longer being found in the Kohala Mountains or in the Kona area....Data on food preferences indicate the species subsists chiefly on fruits of native trees, when in season, and various insects. Comparison of present feeding habits with observations of earlier workers indicates that the diet has changed. This probably has been a consequence of the loss of suitable habitat at lower elevations....One of the earliest and latest daily singers in Hawaii, the Omao has a repertoire of at least three songs and a number of calls. The species exhibits courtship feeding. Five nests averaged 6.4 m from the ground; nesting materials include small twigs, leaves, grasses mosses, and fern pieces. For the first time the species was found to nest either in cavities or on protected platforms. One or two eggs, each marked with large lavender splotches, compose the clutch. Nestlings have flesh-colored skin, black down, and a bright yellow gape pattern. Time from building of the nest to fledging of the young is about 30 days, and the overall breeding season of the species extends at least from February to October.

Blood parasites in noddies and boobies from Brazilian offshore islands - differences between species and influence of nesting habitat.

PubMed

Quillfeldt, Petra; Martínez, Javier; Bugoni, Leandro; Mancini, Patrícia L; Merino, Santiago

2014-03-01

Seabirds are often free from blood parasites, and a recent review suggested that phylogenetic, ecological and life-history parameters can determine the prevalence of blood parasites in seabirds. However, there is a lack of data available from many seabird groups, and a larger database is needed to understand prevalence patterns of blood parasites. We used a molecular screening approach to detect parasites of the genera Plasmodium, Haemoproteus, Leucocytozoon and Babesia in five species of two genera of seabirds that breed on Atlantic Ocean islands off Brazil. The observed patterns differed between the two bird genera. Like other Laridae, brown noddy, Anous stolidus adults were infected with Haemoproteus with low prevalence. Masked boobies, Sula dactylatra and brown boobies, Sula leucogaster were infected with Babesia. Of the latter, mainly juveniles were infected. In all species, intensity of infection (i.e. number of infected erythrocytes) was so low that parasites remained undetected in blood smears. This may explain the absence of major effects on the body condition of birds, although infected juvenile masked boobies were lighter than juveniles that were not infected with Babesia. Two tree-nesting species; black noddy, Anous minutus and red-footed booby, Sula sula did not have blood parasites, suggesting that tree-nesting may reduce the exposure to arthropod vectors compared with ground nesting in these species.

Do male breeding displays function to attract mates or defend territories? The explanatory role of mate and site fidelity

USGS Publications Warehouse

Lanctot, Richard B.; Sandercock, B.K.; Kempenaers, Bart

2000-01-01

Many shorebirds show elaborate breeding displays that include aerial flights and ground displays accompanied by song. The mate attraction hypothesis suggests that breeding displays function to attract mates and maintain pair bonds, whereas the territory defense hypothesis suggests breeding displays function in defining and defending nesting and feeding territories. We tested these hypotheses in the Western Sandpiper (Calidris mauri) by contrasting the duration and level of male breeding displays among pairs that differed in their mate and site fidelity. As predicted by the mate attraction hypothesis, males performed the highest number of song sequences during pair formation, and males paired with their mate of a prior year sang less than males paired to new mates. Further, sitefaithful males mated to a new but experienced mate displayed significantly more than remated males or males new to the area. This suggests a male's prior familiarity with an area and his neighbors does not lessen his display rate as was predicted under the territory defense hypothesis. Limited support for the territory defense hypothesis came from observations of males performing breeding displays with neighboring males along nest territory boundaries. This behavior was short-lived, however, as males abandoned nesting areas after pair-formation and used adjacent or disjointed feeding areas during egg-laying and incubation. Male aggression (i.e., aerial and ground chases), as opposed to breeding displays, appeared to be the principal means of maintaining territory boundaries. Indeed, the rate at which males chased other males remained fairly constant and high throughout the breeding season. Male chasing behavior may also serve as a paternity guard to protect against extra-pair copulations. Our study also found that a female's prior breeding experience in an area correlated with a reduced display rate by her mate, particularly if that mate was new to the area. This indicates female characteristics may not only drive nest initiation, as has been shown in other studies, but are important in determining the duration and extent of male display.

A case of learning to teach elementary science: Investigating beliefs, experiences, and tensions

NASA Astrophysics Data System (ADS)

Bryan, Lynn Ann

This study examines how preservice elementary teacher beliefs and experiences within the context of reflective science teacher education influence the development of professional knowledge. From a cognitive constructivist theoretical perspective, I conducted a case analysis to investigate the beliefs about science teaching and learning held by a preservice teacher (Barbara), identify the tensions she encountered in learning to teach elementary science, understand the frames from which she identified problems of practice, and discern how her experiences influenced the process of reflecting on her own science teaching. From an analysis of interviews, observation, and written documents, I constructed a profile of Barbara's beliefs that consisted of three foundational and three dualistic beliefs about science teaching and learning. Her foundational beliefs concerned: (a) the value of science and science teaching, (b) the nature of scientific concepts and goals of science instruction, and (c) control in the science classroom. Barbara held dualistic beliefs about: (a) how children learn science, (b) the science students' role, and (c) the science teacher's role. The dualistic beliefs formed two contradictory nests of beliefs. One nest, grounded in life-long science learner experiences, reflected a didactic teaching orientation and predominantly guided her practice. The second nest, not well-grounded in experience, embraced a hands-on approach and predominantly guided her vision of practice. Barbara encountered tensions in thinking about science teaching and learning as a result of inconsistencies between her vision of science teaching and her actual practice. Confronting these tensions prompted Barbara to rethink the connections between her classroom actions and students' learning, create new perspectives for viewing her practice, and consider alternative practices more resonant with her visionary beliefs. However, the self-reinforcing belief system created by her didactic nest of beliefs, control beliefs, and belief about the goals of science instruction prevented Barbara from enacting new frames in practice. The findings contribute to an understanding of the relationship between beliefs and experiences in learning to teach and indicate that reframing is crucial in developing professional knowledge. Furthermore, the findings underscore the significance of (a) identifying prospective teachers' beliefs for designing teacher preparation programs, and (b) offering experiences as professionals early in the careers of prospective teachers.

Chemical disguise of myrmecophilous cockroaches and its implications for understanding nestmate recognition mechanisms in leaf-cutting ants.

PubMed

Nehring, Volker; Dani, Francesca R; Calamai, Luca; Turillazzi, Stefano; Bohn, Horst; Klass, Klaus-Dieter; d'Ettorre, Patrizia

2016-08-05

Cockroaches of the genus Attaphila regularly occur in leaf-cutting ant colonies. The ants farm a fungus that the cockroaches also appear to feed on. Cockroaches disperse between colonies horizontally (via foraging trails) and vertically (attached to queens on their mating flights). We analysed the chemical strategies used by the cockroaches to integrate into colonies of Atta colombica and Acromyrmex octospinosus. Analysing cockroaches from nests of two host species further allowed us to test the hypothesis that nestmate recognition is based on an asymmetric mechanism. Specifically, we test the U-present nestmate recognition model, which assumes that detection of undesirable cues (non-nestmate specific substances) leads to strong rejection of the cue-bearers, while absence of desirable cues (nestmate-specific substances) does not necessarily trigger aggression. We found that nests of Atta and Acromyrmex contained cockroaches of two different and not yet described Attaphila species. The cockroaches share the cuticular chemical substances of their specific host species and copy their host nest's colony-specific cuticular profile. Indeed, the cockroaches are accepted by nestmate but attacked by non-nestmate ant workers. Cockroaches from Acromyrmex colonies bear a lower concentration of cuticular substances and are less likely to be attacked by non-nestmate ants than cockroaches from Atta colonies. Nest-specific recognition of Attaphila cockroaches by host workers in combination with nest-specific cuticular chemical profiles suggest that the cockroaches mimic their host's recognition labels, either by synthesizing nest-specific substances or by substance transfer from ants. Our finding that the cockroach species with lower concentration of cuticular substances receives less aggression by both host species fully supports the U-present nestmate recognition model. Leaf-cutting ant nestmate recognition is thus asymmetric, responding more strongly to differences than to similarities.

Origin and Loss of Nested LRRTM/α-Catenin Genes during Vertebrate Evolution

PubMed Central

Uvarov, Pavel; Kajander, Tommi; Airaksinen, Matti S.

2014-01-01

Leucine-rich repeat transmembrane neuronal proteins (LRRTMs) form in mammals a family of four postsynaptic adhesion proteins, which have been shown to bind neurexins and heparan sulphate proteoglycan (HSPG) glypican on the presynaptic side. Mutations in the genes encoding LRRTMs and neurexins are implicated in human cognitive disorders such as schizophrenia and autism. Our analysis shows that in most jawed vertebrates, lrrtm1, lrrtm2, and lrrtm3 genes are nested on opposite strands of large conserved intron of α-catenin genes ctnna2, ctnna1, and ctnna3, respectively. No lrrtm genes could be found in tunicates or lancelets, while two lrrtm genes are found in the lamprey genome, one of which is adjacent to a single ctnna homolog. Based on similar highly positive net charge of lamprey LRRTMs and the HSPG-binding LRRTM3 and LRRTM4 proteins, we speculate that the ancestral LRRTM might have bound HSPG before acquiring neurexins as binding partners. Our model suggests that lrrtm gene translocated into the large ctnna intron in early vertebrates, and that subsequent duplications resulted in three lrrtm/ctnna gene pairs present in most jawed vertebrates. However, we detected three prominent exceptions: (1) the lrrtm3/ctnna3 gene structure is absent in the ray-finned fish genomes, (2) the genomes of clawed frogs contain ctnna1 but lack the corresponding nested (lrrtm2) gene, and (3) contain lrrtm3 gene in the syntenic position but lack the corresponding host (ctnna3) gene. We identified several other protein-coding nested gene structures of which either the host or the nested gene has presumably been lost in the frog or chicken lineages. Interestingly, majority of these nested genes comprise LRR domains. PMID:24587117

Determinants of Spatial Distribution in a Bee Community: Nesting Resources, Flower Resources, and Body Size

PubMed Central

Torné-Noguera, Anna; Rodrigo, Anselm; Arnan, Xavier; Osorio, Sergio; Barril-Graells, Helena; da Rocha-Filho, Léo Correia; Bosch, Jordi

2014-01-01

Understanding biodiversity distribution is a primary goal of community ecology. At a landscape scale, bee communities are affected by habitat composition, anthropogenic land use, and fragmentation. However, little information is available on local-scale spatial distribution of bee communities within habitats that are uniform at the landscape scale. We studied a bee community along with floral and nesting resources over a 32 km2 area of uninterrupted Mediterranean scrubland. Our objectives were (i) to analyze floral and nesting resource composition at the habitat scale. We ask whether these resources follow a geographical pattern across the scrubland at bee-foraging relevant distances; (ii) to analyze the distribution of bee composition across the scrubland. Bees being highly mobile organisms, we ask whether bee composition shows a homogeneous distribution or else varies spatially. If so, we ask whether this variation is irregular or follows a geographical pattern and whether bees respond primarily to flower or to nesting resources; and (iii) to establish whether body size influences the response to local resource availability and ultimately spatial distribution. We obtained 6580 specimens belonging to 98 species. Despite bee mobility and the absence of environmental barriers, our bee community shows a clear geographical pattern. This pattern is mostly attributable to heterogeneous distribution of small (<55 mg) species (with presumed smaller foraging ranges), and is mostly explained by flower resources rather than nesting substrates. Even then, a large proportion (54.8%) of spatial variability remains unexplained by flower or nesting resources. We conclude that bee communities are strongly conditioned by local effects and may exhibit spatial heterogeneity patterns at a scale as low as 500–1000 m in patches of homogeneous habitat. These results have important implications for local pollination dynamics and spatial variation of plant-pollinator networks. PMID:24824445

Is there a weekend bias in clutch-initiation dates from citizen science? Implications for studies of avian breeding phenology.

PubMed

Cooper, Caren B

2014-09-01

Accurate phenology data, such as the timing of migration and reproduction, is important for understanding how climate change influences birds. Given contradictory findings among localized studies regarding mismatches in timing of reproduction and peak food supply, broader-scale information is needed to understand how whole species respond to environmental change. Citizen science-participation of the public in genuine research-increases the geographic scale of research. Recent studies, however, showed weekend bias in reported first-arrival dates for migratory songbirds in databases created by citizen-science projects. I investigated whether weekend bias existed for clutch-initiation dates for common species in US citizen-science projects. Participants visited nests on Saturdays more frequently than other days. When participants visited nests during the laying stage, biased timing of visits did not translate into bias in estimated clutch-initiation dates, based on back-dating with the assumption of one egg laid per day. Participants, however, only visited nests during the laying stage for 25% of attempts of cup-nesting species and 58% of attempts in nest boxes. In some years, in lieu of visit data, participants provided their own estimates of clutch-initiation dates and were asked "did you visit the nest during the laying period?" Those participants who answered the question provided estimates of clutch-initiation dates with no day-of-week bias, irrespective of their answer. Those who did not answer the question were more likely to estimate clutch initiation on a Saturday. Data from citizen-science projects are useful in phenological studies when temporal biases can be checked and corrected through protocols and/or analytical methods.

Determinants of spatial distribution in a bee community: nesting resources, flower resources, and body size.

PubMed

Torné-Noguera, Anna; Rodrigo, Anselm; Arnan, Xavier; Osorio, Sergio; Barril-Graells, Helena; da Rocha-Filho, Léo Correia; Bosch, Jordi

2014-01-01

Understanding biodiversity distribution is a primary goal of community ecology. At a landscape scale, bee communities are affected by habitat composition, anthropogenic land use, and fragmentation. However, little information is available on local-scale spatial distribution of bee communities within habitats that are uniform at the landscape scale. We studied a bee community along with floral and nesting resources over a 32 km2 area of uninterrupted Mediterranean scrubland. Our objectives were (i) to analyze floral and nesting resource composition at the habitat scale. We ask whether these resources follow a geographical pattern across the scrubland at bee-foraging relevant distances; (ii) to analyze the distribution of bee composition across the scrubland. Bees being highly mobile organisms, we ask whether bee composition shows a homogeneous distribution or else varies spatially. If so, we ask whether this variation is irregular or follows a geographical pattern and whether bees respond primarily to flower or to nesting resources; and (iii) to establish whether body size influences the response to local resource availability and ultimately spatial distribution. We obtained 6580 specimens belonging to 98 species. Despite bee mobility and the absence of environmental barriers, our bee community shows a clear geographical pattern. This pattern is mostly attributable to heterogeneous distribution of small (<55 mg) species (with presumed smaller foraging ranges), and is mostly explained by flower resources rather than nesting substrates. Even then, a large proportion (54.8%) of spatial variability remains unexplained by flower or nesting resources. We conclude that bee communities are strongly conditioned by local effects and may exhibit spatial heterogeneity patterns at a scale as low as 500-1000 m in patches of homogeneous habitat. These results have important implications for local pollination dynamics and spatial variation of plant-pollinator networks.

Is there a weekend bias in clutch-initiation dates from citizen science? Implications for studies of avian breeding phenology

NASA Astrophysics Data System (ADS)

Cooper, Caren B.

2014-09-01

Accurate phenology data, such as the timing of migration and reproduction, is important for understanding how climate change influences birds. Given contradictory findings among localized studies regarding mismatches in timing of reproduction and peak food supply, broader-scale information is needed to understand how whole species respond to environmental change. Citizen science—participation of the public in genuine research—increases the geographic scale of research. Recent studies, however, showed weekend bias in reported first-arrival dates for migratory songbirds in databases created by citizen-science projects. I investigated whether weekend bias existed for clutch-initiation dates for common species in US citizen-science projects. Participants visited nests on Saturdays more frequently than other days. When participants visited nests during the laying stage, biased timing of visits did not translate into bias in estimated clutch-initiation dates, based on back-dating with the assumption of one egg laid per day. Participants, however, only visited nests during the laying stage for 25 % of attempts of cup-nesting species and 58 % of attempts in nest boxes. In some years, in lieu of visit data, participants provided their own estimates of clutch-initiation dates and were asked "did you visit the nest during the laying period?" Those participants who answered the question provided estimates of clutch-initiation dates with no day-of-week bias, irrespective of their answer. Those who did not answer the question were more likely to estimate clutch initiation on a Saturday. Data from citizen-science projects are useful in phenological studies when temporal biases can be checked and corrected through protocols and/or analytical methods.

Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation.

PubMed

Geib, Jennifer C; Strange, James P; Galenj, Candace

2015-04-01

Recent reports of global declines in pollinator species imply an urgent need to assess the abundance of native pollinators and density-dependent benefits for linked plants. In this study, we investigated (1) pollinator nest distributions and estimated colony abundances, (2) the relationship between abundances of foraging workers and the number of nests they represent, (3) pollinator foraging ranges, and (4) the relationship between pollinator abundance and plant reproduction. We examined these questions in an alpine ecosystem in the Colorado Rocky Mountains, focusing on four alpine bumble bee species (Bombus balteatus, B. flavifrons, B. bifarius, and B. sylvicola), and two host plants that differ in their degrees of pollinator specialization (Trifolium dasyphyllum and T. parryi). Using microsatellites, we found that estimated colony abundances among Bombus species ranged from ~18 to 78 colonies/0.01 km2. The long-tongued species B. balteatus was most common, especially high above treeline, but the subalpine species B. bifarius was unexpectedly abundant for this elevation range. Nests detected among sampled foragers of each species were correlated with the number of foragers caught. Foraging ranges were smaller than expected for all Bombus species, ranging from 25 to 110 m. Fruit set for the specialized plant, Trifolium parryi, was positively related to the abundance of its Bombus pollinator. In contrast, fruit set for the generalized plant, T. dasyphyllum, was related to abundance of all Bombus species. Because forager abundance was related to nest abundance of each Bombus species and was an equally effective predictor of plant fecundity, forager inventories are probably suitable for assessing the health of outcrossing plant populations. However, nest abundance, rather than forager abundance, better reflects demographic and genetic health in populations of eusocial pollinators such as bumble bees. Development of models incorporating the parameters we have measured here (nest abundance, forager abundance, and foraging distance) could increase the usefulness of foraging worker inventories in nionitoring, managing, and conserving pollinator populations.

Male hatchling production in sea turtles from one of the world’s largest marine protected areas, the Chagos Archipelago

PubMed Central

Esteban, Nicole; Laloë, Jacques-Olivier; Mortimer, Jeanne A.; Guzman, Antenor N.; Hays, Graeme C.

2016-01-01

Sand temperatures at nest depths and implications for hatchling sex ratios of hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) nesting in the Chagos Archipelago, Indian Ocean are reported and compared to similar measurements at rookeries in the Atlantic and Caribbean. During 2012–2014, temperature loggers were buried at depths and in beach zones representative of turtle nesting sites. Data collected for 12,546 days revealed seasonal and spatial patterns of sand temperature. Depth effects were minimal, perhaps modulated by shade from vegetation. Coolest and warmest temperatures were recorded in the sites heavily shaded in vegetation during the austral winter and in sites partially shaded in vegetation during summer respectively. Overall, sand temperatures were relatively cool during the nesting seasons of both species which would likely produce fairly balanced hatchling sex ratios of 53% and 63% male hatchlings, respectively, for hawksbill and green turtles. This result contrasts with the predominantly high female skew reported for offspring at most rookeries around the globe and highlights how local beach characteristics can drive incubation temperatures. Our evidence suggests that sites characterized by heavy shade associated with intact natural vegetation are likely to provide conditions suitable for male hatchling production in a warming world. PMID:26832230

Male hatchling production in sea turtles from one of the world’s largest marine protected areas, the Chagos Archipelago

NASA Astrophysics Data System (ADS)

Esteban, Nicole; Laloë, Jacques-Olivier; Mortimer, Jeanne A.; Guzman, Antenor N.; Hays, Graeme C.

2016-02-01

Sand temperatures at nest depths and implications for hatchling sex ratios of hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) nesting in the Chagos Archipelago, Indian Ocean are reported and compared to similar measurements at rookeries in the Atlantic and Caribbean. During 2012-2014, temperature loggers were buried at depths and in beach zones representative of turtle nesting sites. Data collected for 12,546 days revealed seasonal and spatial patterns of sand temperature. Depth effects were minimal, perhaps modulated by shade from vegetation. Coolest and warmest temperatures were recorded in the sites heavily shaded in vegetation during the austral winter and in sites partially shaded in vegetation during summer respectively. Overall, sand temperatures were relatively cool during the nesting seasons of both species which would likely produce fairly balanced hatchling sex ratios of 53% and 63% male hatchlings, respectively, for hawksbill and green turtles. This result contrasts with the predominantly high female skew reported for offspring at most rookeries around the globe and highlights how local beach characteristics can drive incubation temperatures. Our evidence suggests that sites characterized by heavy shade associated with intact natural vegetation are likely to provide conditions suitable for male hatchling production in a warming world.

Mediation of a corticosterone-induced reproductive conflict.

PubMed

Love, Oliver P; Breuner, Creagh W; Vézina, François; Williams, Tony D

2004-06-01

Current research in birds suggests that a conflict should exist during reproduction for the role of the glucocorticoid corticosterone (CORT). While elevated levels have been correlated with the increased energetic demand of raising offspring, elevated CORT levels have traditionally been implicated in reproductive abandonment. We examined the relationship between CORT and nest desertion in breeding wild female European starlings (Sturnus vulgaris) incorporating analyses of both total circulating levels and 'free', unbound CORT through analysis of corticosteroid-binding globulin (CBG). Free baseline CORT levels of nest-abandoning birds were significantly higher than nonabandoning birds within each stage, with chick-rearing birds exhibiting the highest free baseline CORT levels, while concurrently remaining the most resistant stage to nest desertion. Elevated free baseline CORT levels in chick-rearing birds were not due to increased total CORT secretion, but rather to a decrease in CBG levels. Overall, our results suggest that CORT and CBG interact to play a role in mediating the increased energetic demand of offspring, while minimizing the chances of nest desertion, thereby alleviating any potential behavioral conflict for CORT during reproduction. Furthermore, these results demonstrate that the traditional view of the role of CORT during reproduction is much more complex than previously appreciated. Together with mounting evidence, we suggest that elevated corticosteroid levels are an inherent and necessary part of reproduction in nonmammalian tetrapods.

Male hatchling production in sea turtles from one of the world's largest marine protected areas, the Chagos Archipelago.

PubMed

Esteban, Nicole; Laloë, Jacques-Olivier; Mortimer, Jeanne A; Guzman, Antenor N; Hays, Graeme C

2016-02-02

Sand temperatures at nest depths and implications for hatchling sex ratios of hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) nesting in the Chagos Archipelago, Indian Ocean are reported and compared to similar measurements at rookeries in the Atlantic and Caribbean. During 2012-2014, temperature loggers were buried at depths and in beach zones representative of turtle nesting sites. Data collected for 12,546 days revealed seasonal and spatial patterns of sand temperature. Depth effects were minimal, perhaps modulated by shade from vegetation. Coolest and warmest temperatures were recorded in the sites heavily shaded in vegetation during the austral winter and in sites partially shaded in vegetation during summer respectively. Overall, sand temperatures were relatively cool during the nesting seasons of both species which would likely produce fairly balanced hatchling sex ratios of 53% and 63% male hatchlings, respectively, for hawksbill and green turtles. This result contrasts with the predominantly high female skew reported for offspring at most rookeries around the globe and highlights how local beach characteristics can drive incubation temperatures. Our evidence suggests that sites characterized by heavy shade associated with intact natural vegetation are likely to provide conditions suitable for male hatchling production in a warming world.

Occurrence and Distribution of Mercury in the SurficialAquifer, Long Neck Peninsula, Sussex County, Delaware, 2003-04

USGS Publications Warehouse

Koterba, Michael T.; Andres, A. Scott; Vrabel, Joseph; Crilley, Dianna M.; Szabo, Zoltan; DeWild, John F.; Aiken, George R.; Reyes-Padro, Betzaida

2006-01-01

In January 2001, mercury (Hg) was detected (500 nanograms per liter, ng/L, or greater) in the distribution system of the Long Neck Water Company (LNWC), Pot Nets, Delaware. By April 2001, two LNWC production wells had been taken off-line because discharge concentrations of total mercury (HgT) either had exceeded or approached the Federal limit of 2,000 ng/L. From October 2003 through January 2005, the U.S. Geological Survey, Delaware Geological Survey, and Delaware Department of Natural Resources and Environmental Control conducted a cooperative study to (a) determine if the Hg contamination was widespread, (b) identify possible forms of Hg in ground water, and (c) examine Hg occurrence in relation to (geo)chemical conditions and characteristics of ground water and sediment in the surficial aquifer on the Long Neck Peninsula, Sussex County, Delaware. An initial water-quality survey conducted with samples from 22 production wells revealed that concentrations of HgT in ground water in the surficial aquifer ranged from 0.11 to 1,820 ng/L. Shallow ground water (less than 120 feet below land surface) throughout most of the peninsula, including that which contained elevated concentrations of HgT (exceeding 100 ng/L), appeared to be affected by human activities. All samples contained volatile organic compounds (VOCs) and elevated nitrate-nitrogen (NO3-N, exceeding 0.4 milligrams per liter, mg/L). Most (16 of 22) samples had elevated specific conductance (SC, in excess of 100 microsiemens per centimeter at 25 degrees Celsius). Elevated concentrations of HgT, however, only occurred in five production wells in the Pot Nets Bayside and Lakeside communities. The vertical distribution of HgT in shallow ground water (less than 80 feet below land surface) was determined with samples collected at 5 to 6 vertical-nest short-screened (2 - 5-foot length) monitoring wells installed near Bayside and Lakeside production wells with the highest HgT concentrations (exceeding 1,000 ng/L). Elevated concentrations ofHgT (100-6,380 ng/L) occurred in the shallow aquifer near each well at different depths. Chemical analyses of selected soil, fill, and aquifer sediment samples, obtained during the installation of nested wells, indicated that little HgT occurred in soil or fill at either site (40 micrograms per kilogram, ?g/kg, or less). No HgT was detected (less than 20 ?g/kg) in aquifer sediment samples. These low HgT concentrations imply that neither the soil, fill, nor aquifer sediment was a likely source of the elevated Hg in ground water. Given Hg occurrence appeared to be a ground-water transport phenomenon, the forms of Hg in transport were investigated. Differences in HgT concentrations between raw and filtered (0.1- and (or) 0.4-absolute micrometer pore size) samples from nested wells were random in sign and similar in magnitude to the variability in measuring HgT attributed to field and laboratory methods (? 5-10 percent, for HgT concentrations exceeding 100 ng/L). Thus, Hg transport likely occurred in a dissolved or fine-colloidal nonparticulate phase. Methyl mercury (HgMe) only was detected at low concentrations (0.06 ng/L or less) in nested-well samples with low to moderate concentrations of HgT (less than 366 ng/L). Whether HgMe occurred at similar concentrations in samples with high HgT concentrations was unresolved due to a sample-matrix interference problem. Potential complex forms of Hg were investigated in relation to the occurrence of selected ligands (organic carbon, sulfide, and chloride concentrations) and geochemical conditions (for example, pH and dissolved oxygen concentrations). Only dissolved organic carbon (DOC) appeared directly related to Hg occurrence. Elevated concentrations of HgT and DOC co-occurred in ground water at both Pot Nets sites. The average concentration of DOC was about four times greater in samples from the Pot Nets wells with the highest HgT concentrations (exceeding 1,000 ng/L) than in most Pot Nets o

Swooping in the Suburbs; Parental Defence of an Abundant Aggressive Urban Bird against Humans

PubMed Central

Lees, Daniel; Sherman, Craig D. H.; Maguire, Grainne S.; Dann, Peter; Cardilini, Adam P. A.; Weston, Michael A.

2013-01-01

Simple Summary We studied the defensive behaviour of 94 pairs of nesting Masked Lapwings, Vanellus miles, in response to two types of human stimuli: a pedestrian and a person pushing a lawn mower. We also examined the effectiveness of a commonly promoted deterrent to swooping (the presence of mock eyes placed on the back of a person’s head) for each stimulus type. Masked Lapwings responded more aggressively to a person pushing a lawn mower compared with pedestrians. Birds also remained closer to the nest in the presence of a lawn mower. The presence of eye stickers on the back of a pedestrian’s head decreased swooping behaviour; however, the presence of eye stickers worn by a person pushing a lawn mower increased swooping behaviour. Abstract Masked Lapwings, Vanellus miles, often come into ‘conflict’ with humans, because they often breed in close proximity to humans and actively defend their ground nests through aggressive behaviour, which typically involves swooping. This study examined whether defensive responses differed when nesting birds were confronted with different human stimuli (‘pedestrian alone’ vs. ‘person pushing a lawn mower’ approaches to nests) and tested the effectiveness of a commonly used deterrent (mock eyes positioned on the top or back of a person’s head) on the defensive response. Masked Lapwings did not swoop closer to a person with a lawn mower compared with a pedestrian, but flushed closer and remained closer to the nest in the presence of a lawn mower. The presence of eye stickers decreased (pedestrians) and increased (lawn mowers) swooping behaviour. Masked Lapwings can discriminate between different human activities and adjust their defensive behaviour accordingly. We also conclude that the use of eye stickers is an effective method to mitigate the human-lapwing ‘conflict’ in some, but not all, circumstances. PMID:26479532

Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic

USGS Publications Warehouse

Ross, Megan V.; Alisaukas, Ray T.; Douglas, David C.; Kellett, Dana K.

2017-01-01

A full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. The process of recruitment in particular may be protracted over several years, and can depend on numerous ecological complexities until sexually mature adulthood is attained. We addressed long-term declines (23 breeding seasons, 1992–2014) in the per capita production of young by both Ross's Geese (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) nesting at Karrak Lake in Canada's central Arctic. During this period, there was a contemporaneous increase from 0.4 to 1.1 million adults nesting at this colony. We evaluated whether (1) density-dependent nutritional deficiencies of pre-breeding females or (2) phenological mismatch between peak gosling hatch and peak forage quality, inferred from NDVI on the brood-rearing areas, may have been behind decadal declines in the per capita production of goslings. We found that, in years when pre-breeding females arrived to the nesting grounds with diminished nutrient reserves, the proportional composition of young during brood-rearing was reduced for both species. Furthermore, increased mismatch between peak gosling hatch and peak forage quality contributed additively to further declines in gosling production, in addition to declines caused by delayed nesting with associated subsequent negative effects on clutch size and nest success. The degree of mismatch increased over the course of our study because of advanced vegetation phenology without a corresponding advance in Goose nesting phenology. Vegetation phenology was significantly earlier in years with warm surface air temperatures measured in spring (i.e., 25 May–30 June). We suggest that both increased phenological mismatch and reduced nutritional condition of arriving females were behind declines in population-level recruitment, leading to the recent attenuation in population growth of Snow Geese.