Sample records for narwhal habitat associations

  1. Use of Glacial Fronts by Narwhals (Monodon monoceros) in West Greenland

    NASA Astrophysics Data System (ADS)

    Laidre, K. L.

    2015-12-01

    Glacial fronts in Greenland are known to be important summer habitat for narwhals (Monodon monoceros), as freshwater runoff and sediment discharge may aggregate prey at the terminus. We investigated the importance of glacial habitat characteristics in determining narwhal visitation. Narwhals (n=18) were instrumented with satellite transmitters in September 1993-1994 and 2006-2007 in Melville Bay, West Greenland. Daily narwhal locations were interpolated using a correlated random walk based on observed filtered locations and associated positional error. We also compiled a database on physical features of 41 glaciers along the northwest Greenland coast. This covered the entire coastal region with narwhal activity. Parameters included glacier ice velocity (km/yr) from radar satellite data, glacier front advance and retreat, and glacier width (km) at the ice-ocean interface derived using front position data digitized from 20-100m resolution radar image mosaics and Landsat imagery. We also quantified relative volumes and extent of glacial ice discharge, thickness of the glacial ice at the terminus (m), and water depth at the terminus (m) from gravity and airborne radar data, sediment flux from satellite-based analysis, and freshwater runoff from a regional atmospheric climate model (RACMO2.3). We quantified whale visits to glaciers at three distances (5, 7, and 10 km) and conducted proximity analyses on annual and monthly time steps. We estimated 1) narwhal presence or absence, 2) the number of 24 h periods spent at glaciers, and 3) the fraction of study animals that visited each glacier. The use of glacial habitat by narwhals expanded to the north and south between the 1990s (n=9 unique glaciers visited) and the 2000s (n=30 visited), likely due to loss of summer fast ice and later fall freeze-up trends (3.5 weeks later since 1979). We used a generalized linear mixed effects framework to quantify the glacier and fjord habitat characteristics preferred by narwhals.

  2. Use of glacial fronts by narwhals (Monodon monoceros) in West Greenland

    PubMed Central

    Moon, Twila; Hauser, Donna D. W.; McGovern, Richard; Heide-Jørgensen, Mads Peter; Dietz, Rune; Hudson, Ben

    2016-01-01

    Glacial fronts are important summer habitat for narwhals (Monodon monoceros); however, no studies have quantified which glacial properties attract whales. We investigated the importance of glacial habitats using telemetry data from n = 15 whales tagged in September of 1993, 1994, 2006 and 2007 in Melville Bay, West Greenland. For 41 marine-terminating glaciers, we estimated (i) narwhal presence/absence, (ii) number of 24 h periods spent at glaciers and (iii) the fraction of narwhals that visited each glacier (at 5, 7 and 10 km) in autumn. We also compiled data on glacier width, ice thickness, ice velocity, front advance/retreat, area and extent of iceberg discharge, bathymetry, subglacial freshwater run-off and sediment flux. Narwhal use of glacial habitats expanded in the 2000s probably due to reduced summer fast ice and later autumn freeze-up. Using a generalized multivariate framework, glacier ice front thickness (vertical height in the water column) was a significant covariate in all models. A negative relationship with glacier velocity was included in several models and glacier front width was a significant predictor in the 2000s. Results suggest narwhals prefer glaciers with potential for higher ambient freshwater melt over glaciers with silt-laden discharge. This may represent a preference for summer freshwater habitat, similar to other Arctic monodontids. PMID:27784729

  3. Use of glacial fronts by narwhals (Monodon monoceros) in West Greenland.

    PubMed

    Laidre, Kristin L; Moon, Twila; Hauser, Donna D W; McGovern, Richard; Heide-Jørgensen, Mads Peter; Dietz, Rune; Hudson, Ben

    2016-10-01

    Glacial fronts are important summer habitat for narwhals (Monodon monoceros); however, no studies have quantified which glacial properties attract whales. We investigated the importance of glacial habitats using telemetry data from n = 15 whales tagged in September of 1993, 1994, 2006 and 2007 in Melville Bay, West Greenland. For 41 marine-terminating glaciers, we estimated (i) narwhal presence/absence, (ii) number of 24 h periods spent at glaciers and (iii) the fraction of narwhals that visited each glacier (at 5, 7 and 10 km) in autumn. We also compiled data on glacier width, ice thickness, ice velocity, front advance/retreat, area and extent of iceberg discharge, bathymetry, subglacial freshwater run-off and sediment flux. Narwhal use of glacial habitats expanded in the 2000s probably due to reduced summer fast ice and later autumn freeze-up. Using a generalized multivariate framework, glacier ice front thickness (vertical height in the water column) was a significant covariate in all models. A negative relationship with glacier velocity was included in several models and glacier front width was a significant predictor in the 2000s. Results suggest narwhals prefer glaciers with potential for higher ambient freshwater melt over glaciers with silt-laden discharge. This may represent a preference for summer freshwater habitat, similar to other Arctic monodontids. © 2016 The Author(s).

  4. Sustained disruption of narwhal habitat use and behavior in the presence of Arctic killer whales

    PubMed Central

    Breed, Greg A.; Matthews, Cory J. D.; Marcoux, Marianne; Higdon, Jeff W.; LeBlanc, Bernard; Petersen, Stephen D.; Orr, Jack; Reinhart, Natalie R.; Ferguson, Steven H.

    2017-01-01

    Although predators influence behavior of prey, analyses of electronic tracking data in marine environments rarely consider how predators affect the behavior of tracked animals. We collected an unprecedented dataset by synchronously tracking predator (killer whales, N = 1; representing a family group) and prey (narwhal, N = 7) via satellite telemetry in Admiralty Inlet, a large fjord in the Eastern Canadian Arctic. Analyzing the movement data with a switching-state space model and a series of mixed effects models, we show that the presence of killer whales strongly alters the behavior and distribution of narwhal. When killer whales were present (within about 100 km), narwhal moved closer to shore, where they were presumably less vulnerable. Under predation threat, narwhal movement patterns were more likely to be transiting, whereas in the absence of threat, more likely resident. Effects extended beyond discrete predatory events and persisted steadily for 10 d, the duration that killer whales remained in Admiralty Inlet. Our findings have two key consequences. First, given current reductions in sea ice and increases in Arctic killer whale sightings, killer whales have the potential to reshape Arctic marine mammal distributions and behavior. Second and of more general importance, predators have the potential to strongly affect movement behavior of tracked marine animals. Understanding predator effects may be as or more important than relating movement behavior to resource distribution or bottom-up drivers traditionally included in analyses of marine animal tracking data. PMID:28223481

  5. Sustained disruption of narwhal habitat use and behavior in the presence of Arctic killer whales.

    PubMed

    Breed, Greg A; Matthews, Cory J D; Marcoux, Marianne; Higdon, Jeff W; LeBlanc, Bernard; Petersen, Stephen D; Orr, Jack; Reinhart, Natalie R; Ferguson, Steven H

    2017-03-07

    Although predators influence behavior of prey, analyses of electronic tracking data in marine environments rarely consider how predators affect the behavior of tracked animals. We collected an unprecedented dataset by synchronously tracking predator (killer whales, [Formula: see text] = 1; representing a family group) and prey (narwhal, [Formula: see text] = 7) via satellite telemetry in Admiralty Inlet, a large fjord in the Eastern Canadian Arctic. Analyzing the movement data with a switching-state space model and a series of mixed effects models, we show that the presence of killer whales strongly alters the behavior and distribution of narwhal. When killer whales were present (within about 100 km), narwhal moved closer to shore, where they were presumably less vulnerable. Under predation threat, narwhal movement patterns were more likely to be transiting, whereas in the absence of threat, more likely resident. Effects extended beyond discrete predatory events and persisted steadily for 10 d, the duration that killer whales remained in Admiralty Inlet. Our findings have two key consequences. First, given current reductions in sea ice and increases in Arctic killer whale sightings, killer whales have the potential to reshape Arctic marine mammal distributions and behavior. Second and of more general importance, predators have the potential to strongly affect movement behavior of tracked marine animals. Understanding predator effects may be as or more important than relating movement behavior to resource distribution or bottom-up drivers traditionally included in analyses of marine animal tracking data.

  6. Research Spotlight: Narwhals document continued warming of Baffin Bay

    NASA Astrophysics Data System (ADS)

    Kumar, Mohi

    2011-03-01

    Baffin Bay, situated between northern Greenland and Canada, is a major gateway between waters from the North Atlantic and Arctic oceans. Dynamics within the bay help govern how much water from the Arctic flows south and sinks to form North Atlantic Deep Water, a deep current that drives ocean circulation on a global scale. Unfortunately, monitoring the deep reaches of Baffin Bay throughout the year is difficult—most oceanographic data are collected in the summer when the area is ice free. To overcome this inability to collect data in harsh winter conditions, Laidre et al. hit upon a novel solution: mounting instruments on narwhals to collect temperature and depth data. Narwhals, a top predator in this frigid ecosystem, make annual migrations from summering grounds in the Canadian High Arctic and western Greenland to wintering grounds in the dense offshore pack ice of Baffin Bay. Moreover, narwhals, which rank among the deepest-diving whales in the world, dive extensively and repeatedly to depths exceeding 1800 meters under pack ice to reach their major food source, the flatfish that swarm on the seafloor of Baffin Bay. Narwhal dives are nearly vertical, making this whale an ideal platform on which to mount surveying instruments. (Journal of Geophysical Research-Oceans, doi:10.1029/2009JC005820, 2010)

  7. Highly Directional Sonar Beam of Narwhals (Monodon monoceros) Measured with a Vertical 16 Hydrophone Array.

    PubMed

    Koblitz, Jens C; Stilz, Peter; Rasmussen, Marianne H; Laidre, Kristin L

    2016-01-01

    Recordings of narwhal (Monodon monoceros) echolocation signals were made using a linear 16 hydrophone array in the pack ice of Baffin Bay, West Greenland in 2013 at eleven sites. An average -3 dB beam width of 5.0° makes the narwhal click the most directional biosonar signal reported for any species to date. The beam shows a dorsal-ventral asymmetry with a narrower beam above the beam axis. This may be an evolutionary advantage for toothed whales to reduce echoes from the water surface or sea ice surface. Source level measurements show narwhal click intensities of up to 222 dB pp re 1 μPa, with a mean apparent source level of 215 dB pp re 1 μPa. During ascents and descents the narwhals perform scanning in the vertical plane with their sonar beam. This study provides valuable information for reference sonar parameters of narwhals and for the use of acoustic monitoring in the Arctic.

  8. Highly Directional Sonar Beam of Narwhals (Monodon monoceros) Measured with a Vertical 16 Hydrophone Array

    PubMed Central

    Koblitz, Jens C.; Stilz, Peter; Rasmussen, Marianne H.; Laidre, Kristin L.

    2016-01-01

    Recordings of narwhal (Monodon monoceros) echolocation signals were made using a linear 16 hydrophone array in the pack ice of Baffin Bay, West Greenland in 2013 at eleven sites. An average -3 dB beam width of 5.0° makes the narwhal click the most directional biosonar signal reported for any species to date. The beam shows a dorsal-ventral asymmetry with a narrower beam above the beam axis. This may be an evolutionary advantage for toothed whales to reduce echoes from the water surface or sea ice surface. Source level measurements show narwhal click intensities of up to 222 dB pp re 1 μPa, with a mean apparent source level of 215 dB pp re 1 μPa. During ascents and descents the narwhals perform scanning in the vertical plane with their sonar beam. This study provides valuable information for reference sonar parameters of narwhals and for the use of acoustic monitoring in the Arctic. PMID:27828956

  9. Accumulation, metabolism, and food-chain transfer of chlorinated and brominated contaminants in subadult white whales (Delphinapterus leucas) and narwhals (Monodon monoceros) from Svalbard, Norway.

    PubMed

    Wolkers, H; Lydersen, C; Kovacs, K M; Burkow, I; van Bavel, B

    2006-01-01

    The concentrations and patterns of polychlorinated biphenyls (PCBs), chlorinated pesticides, and polybrominated diphenyl ethers (PBDEs) were studied in white whales (Delphinapterus leucas) and narwhals (Monodon monoceros) from Svalbard, Norway. In addition, their main food items were included in the study. In the whales, a broad range of pollutants was found in relatively high concentrations. PCBs and pesticides were approximately 3000 and 8000 ng/g lipid, respectively, for white whales and three times higher for narwhals. PBDEs 47 were approximately 70 ng/g lipid for white whales and 170 ng/g lipid for narwhals. Compared with other marine mammals from the same area, contaminant levels are among the highest levels ever measured. These high levels are likely in part because of a decreased capacity to metabolize contaminants. Metabolic indices indicated that most compounds accumulate to the same degree in white whales and narwhals, but for some toxaphenes and chlordanes, narwhals might have a decreased metabolism and consequently a higher accumulation. The three-times-higher contaminant levels in blubber of narwhals was further explained by substantially higher contaminant levels in their more benthic diet. The high levels and broad pattern of accumulating pollutants make white whales and narwhals excellent indicators for a wide range of contaminants in the Arctic.

  10. Mercury distribution in the skin of beluga (Delphinapterus leucas) and narwhal (Monodon monoceros) from the Canadian Arctic and mercury burdens and excretion by moulting.

    PubMed

    Wagemann, R; Kozlowska, H

    2005-12-01

    Beluga and narwhal skin as a whole (in Inuktitut known as "muktuk") is considered to be a delicacy by native Canadian and Greenland people. Individual strata of the skin, and muscle from 27 beluga from the western, and 20 narwhal from the eastern Canadian Arctic, were analyzed for mercury and the thickness and density of each skin layer was measured. Mercury was not uniformly distributed in the skin, but increased outwardly with each layer. The concentration was only 0.29 and 0.16 microg/g (wet wt) in the innermost layer (dermis) of belugas and narwhal respectively, and 1.5 and 1.4 microg/g (wet wt) in the outermost layer (degenerative epidermis) of beluga and narwhal, respectively. There was a significant (alpha=0.05) association between age and mercury concentration in each skin layer, the regression coefficients progressively increasing from the inner layer (dermis) to the outer layer: 0.011-0.063 microg/g year-1; 0.034 microg/g year-1 for skin as a whole; 0.054 microg/g year-1 for muscle. The concentration of total mercury was 0.84 and 0.59 microg/g (wet wt) in skin as a whole (muktuk) of beluga and narwhal respectively, and 0.12 and 0.03 microg/g in blubber, respectively. The average, total mercury concentration in muscle tissue was 1.4 and 0.81 microg/g wet wt, in beluga and narwhal respectively, exceeding (except for blubber) the Canadian Government's Guideline (0.5 microg/g wet wt) for fish export and consumption. The skin surface area of an average-size beluga and narwhal was estimated (6.10 and 6.50 m2, respectively), as were excretions of mercury through moulting (13,861 and 6721 microg year-1; 14 and 7 mg year-1) for belugas and narwhal, respectively. The whole-body mercury burden (699,300 microg; 700 mg) for a 1000 kg beluga and its various tissues were estimated, as was the fraction of mercury excreted by moulting (2-0.42% of the whole-body burden). Annual mercury burden increments in beluga skin, muscle and the whole body were estimated (2750; 17

  11. The unicorn and the narwhal: a tale of the tooth.

    PubMed

    Christen, Arden G; Christen, Joan A

    2011-01-01

    From as far back as the early Roman era, detailed descriptions and artistic images of the unicorn have been imagined. In Europe, the Mediterranean and the Far East, this creature became accepted as real. Although such an animal had never actually been seen, it was said to have the appearance of a horse, the beard and cloven hooves of a goat, the tail of a lion, and a single, spear-like horn protruding from the center of its forehead. The unicorn myth originated shortly after unidentified horn-like objects, from six to ten feet long, began to appear in ancient European marketplaces. Physicians quickly ascribed outlandish healing properties to these horns, pulverizing them for the treatment of various diseases. In 1638, a Danish zoologist challenged these claims and provided evidence that the so-called "unicorn horn" was actually the tusk (tooth) of the narwhal from the Arctic seas. However, his findings remained unheeded for the next 100 years. This paper explains how the myth of the unicorn and the purported powers contained within the substance of its magical horn evolved from the ages-old spoils of the Arctic fishing trade, where the narwhal was primarily speared for food and secondarily, for the export value of its ivory tusk. This unusually long, pointed and protruding single tooth, which breaks through the upper lip and the left jaw of each male narwhal, became a highly valuable commodity over the following centuries, due to its believed supernatural origins and curative qualities.

  12. Behavioral Ecology of Narwhals in a Changing Arctic

    DTIC Science & Technology

    2015-09-30

    ecology in the pack ice of Baffin Bay. We will collect data on the species’ acoustic , movement, and diving ecology in the offshore pack ice of Baffin...Bay over a 4 year long research program with three ecological focus areas ( acoustic ecology, sea ice ecology, and foraging ecology). Our...questions: 2 1. Acoustic ecology: What are baseline characteristics of the acoustic repertoire of narwhals in the offshore Baffin Bay pack ice

  13. Behavioral Ecology of Narwhals in a Changing Arctic

    DTIC Science & Technology

    2013-09-30

    What are the spatial and temporal trends in the occurrence of killer whales in West Greenland? Given the loss of annual sea ice and purported...increase in killer whales in the Canadian Arctic, do killer whale catch and observation data from West Greenland follow this trend and have narwhals been...sampling in the Northeast Atlantic have documented killer whales (Orcinus orca), the largest delphinid, produce whistles with the highest

  14. NEKTON-HABITAT ASSOCIATIONS IN YAQUINA BAY, OREGON

    EPA Science Inventory

    Habitat-based ecological risk assessments rely, in part, on estimates of the ecological value of the habitats at risk. To estimate estuarine habitat values with respect to the nekton (small fish, crabs and other invertebrates), we determined nekton-habitat associations in four i...

  15. Fractal analysis of narwhal space use patterns.

    PubMed

    Laidre, Kristin L; Heide-Jørgensen, Mads P; Logsdon, Miles L; Hobbs, Roderick C; Dietz, Rune; VanBlaricom, Glenn R

    2004-01-01

    Quantifying animal movement in response to a spatially and temporally heterogeneous environment is critical to understanding the structural and functional landscape influences on population viability. Generalities of landscape structure can easily be extended to the marine environment, as marine predators inhabit a patchy, dynamic system, which influences animal choice and behavior. An innovative use of the fractal measure of complexity, indexing the linearity of movement paths over replicate temporal scales, was applied to satellite tracking data collected from narwhals (Monodon monoceros) (n = 20) in West Greenland and the eastern Canadian high Arctic. Daily movements of individuals were obtained using polar orbiting satellites via the ARGOS data location and collection system. Geographic positions were filtered to obtain a daily good quality position for each whale. The length of total pathway was measured over seven different temporal length scales (step lengths), ranging from one day to one week, and a seasonal mean was calculated. Fractal dimension (D) was significantly different between seasons, highest during summer (D = 1.61, SE 0.04) and winter (D = 1.69, SE 0.06) when whales made convoluted movements in focal areas. Fractal dimension was lowest during fall (D = 1.34, SE 0.03) when whales were migrating south ahead of the forming sea ice. There were no significant effects of size category or sex on fractal dimension by season. The greater linearity of movement during the migration period suggests individuals do not intensively forage on patchy resources until they arrive at summer or winter sites. The highly convoluted movements observed during summer and winter suggest foraging or searching efforts in localized areas. Significant differences between the fractal dimensions on two separate wintering grounds in Baffin Bay suggest differential movement patterns in response to the dynamics of sea ice.

  16. Benthic macrofauna habitat associations in Willapa Bay, Washington, USA

    NASA Astrophysics Data System (ADS)

    Ferraro, Steven P.; Cole, Faith A.

    2007-02-01

    Estuary-wide benthic macrofauna-habitat associations in Willapa Bay, Washington, United States, were determined for 4 habitats (eelgrass [ Zostera marina], Atlantic cordgrass [ Spartina alterniflora], mud shrimp [ Upogebia pugettensis], ghost shrimp [ Neotrypaea californiensis]) in 1996 and 7 habitats (eelgrass, Atlantic cordgrass, mud shrimp, ghost shrimp, oyster [ Crassostrea gigas], bare mud/sand, subtidal) in 1998. Most benthic macrofaunal species inhabited multiple habitats; however, 2 dominants, a fanworm, Manayunkia aestuarina, in Spartina, and a sand dollar, Dendraster excentricus, in subtidal, were rare or absent in all other habitats. Benthic macrofaunal Bray-Curtis similarity varied among all habitats except eelgrass and oyster. There were significant differences among habitats within- and between-years on several of the following ecological indicators: mean number of species ( S), abundance ( A), biomass ( B), abundance of deposit (AD), suspension (AS), and facultative (AF) feeders, Swartz's index (SI), Brillouin's index ( H), and jackknife estimates of habitat species richness (HSR). In the 4 habitats sampled in both years, A was about 2.5× greater in 1996 (a La Niña year) than 1998 (a strong El Niño year) yet relative values of S, A, B, AD, AS, SI, and H among the habitats were not significantly different, indicating strong benthic macrofauna-habitat associations despite considerable climatic and environmental variability. In general, the rank order of habitats on indicators associated with high diversity and productivity (high S, A, B, SI, H, HSR) was eelgrass = oyster ≥ Atlantic cordgrass ≥ mud shrimp ≥ bare mud/sand ≥ ghost shrimp = subtidal. Vegetation, burrowing shrimp, and oyster density and sediment %silt + clay and %total organic carbon were generally poor, temporally inconsistent predictors of ecological indicator variability within habitats. The benthic macrofauna-habitat associations in this study can be used to help identify

  17. A variance-decomposition approach to investigating multiscale habitat associations

    USGS Publications Warehouse

    Lawler, J.J.; Edwards, T.C.

    2006-01-01

    The recognition of the importance of spatial scale in ecology has led many researchers to take multiscale approaches to studying habitat associations. However, few of the studies that investigate habitat associations at multiple spatial scales have considered the potential effects of cross-scale correlations in measured habitat variables. When cross-scale correlations in such studies are strong, conclusions drawn about the relative strength of habitat associations at different spatial scales may be inaccurate. Here we adapt and demonstrate an analytical technique based on variance decomposition for quantifying the influence of cross-scale correlations on multiscale habitat associations. We used the technique to quantify the variation in nest-site locations of Red-naped Sapsuckers (Sphyrapicus nuchalis) and Northern Flickers (Colaptes auratus) associated with habitat descriptors at three spatial scales. We demonstrate how the method can be used to identify components of variation that are associated only with factors at a single spatial scale as well as shared components of variation that represent cross-scale correlations. Despite the fact that no explanatory variables in our models were highly correlated (r < 0.60), we found that shared components of variation reflecting cross-scale correlations accounted for roughly half of the deviance explained by the models. These results highlight the importance of both conducting habitat analyses at multiple spatial scales and of quantifying the effects of cross-scale correlations in such analyses. Given the limits of conventional analytical techniques, we recommend alternative methods, such as the variance-decomposition technique demonstrated here, for analyzing habitat associations at multiple spatial scales. ?? The Cooper Ornithological Society 2006.

  18. NEKTON-HABITAT ASSOCIATIONS IN A PACIFIC NORTHWEST (USA) ESTUARY

    EPA Science Inventory

    Nekton−habitat associations were determined in Yaquina Bay, Oregon, United States, using a stratified-by-habitat, random, estuary-wide sampling design. Three habitats (intertidal eelgrass [Zostera marina], mud shrimp [Upogebia pugettensis], and ghost shrimp [Neotrypaea californie...

  19. Saproxylic Hemiptera Habitat Associations

    Treesearch

    Michael D. Ulyshen; James L. Hanula; Robert L. Blinn; Gene. Kritsky

    2012-01-01

    Understanding the habitat requirements of organisms associated with dead wood is important in order to conserve them in managed forests. Unfortunately, many of the less diverse saproxylic taxa, including Hemiptera, remain largely unstudied. An effort to rear insects from dead wood taken from two forest types (an upland pine-dominated and a bottomland mixed hardwood),...

  20. Chapter 19: Marbled Murrelet Habitat Associations in Oregon

    Treesearch

    Jeffrey J. Grenier; S. Kim Nelson

    1995-01-01

    We described habitat associations of Marbled Murrelet (Brachyramphus marmoratus) nesting (n = 10) and occupied (n = 184) sites in Oregon. We compared habitat characteristics of 177 occupied sites to a random sample of 9,625 sites (n = 531) of unknown murrelet status. In addition, we briefly...

  1. Local-scale habitat associations of grassland birds in southwestern Minnesota

    USGS Publications Warehouse

    Elliott, Lisa H.; Johnson, Douglas H.

    2017-01-01

    Conservation of obligate grassland species requires not only the protection of a sufficiently large area of habitat but also the availability of necessary vegetation characteristics for particular species. As a result land managers must understand which habitat characteristics are important for their target species. To identify the habitat associations of eight species of grassland birds, we conducted bird and vegetation surveys on 66 grassland habitat patches in southwestern Minnesota in 2013 and 2014. Species of interest included sedge wren (Cistothorus platensis), Savannah sparrow (Passerculus sandwichensis), grasshopper sparrow (Ammodramus savannarum), Henslow's sparrow (Ammodramus henslowii), dickcissel (Spiza americana), bobolink (Dolichonyx oryzivorus), and western meadowlark (Sturnella neglecta). We calculated correlation coefficients between vegetation variables and species density as measures of linear association. We assessed curvilinear relationships with loess plots. We found grassland birds on 95.5% of surveyed sites, indicating remnant prairie in southwestern Minnesota is used by grassland birds. In general individual species showed different patterns of association and most species were tolerant of a wide variety of habitat conditions. The most consistent pattern was a negative association with both the quantity and proximity of trees. Our findings that individual species have different habitat preferences suggest that prairie resource managers may need to coordinate management efforts in order to create a mosaic of habitat types to support multiple species, though tree control will be an important and ongoing management activity at the individual site level.

  2. BENTHIC MACROFAUNA-HABITAT ASSOCIATIONS IN WILLAPA BAY, WASHINGTON, USA

    EPA Science Inventory

    Estuary-wide benthic macrofauna-habitat associations in Willapa Bay, Washington, United States, were determined for 4 habitats (eelgrass [Zostera marina], Atlantic cordgrass [Spartina alterniflora], mud shrimp [Upogebia pugettensis], ghost shrimp [Neotrypaea californiensis]) in 1...

  3. The narwhal (Monodon monoceros) cementum-dentin junction: a functionally graded biointerphase.

    PubMed

    Grandfield, Kathryn; Chattah, Netta Lev-Tov; Djomehri, Sabra; Eidelmann, Naomi; Eichmiller, Frederick C; Webb, Samuel; Schuck, P James; Nweeia, Martin; Ho, Sunita P

    2014-08-01

    In nature, an interface between dissimilar tissues is often bridged by a graded zone, and provides functional properties at a whole organ level. A perfect example is a "biological interphase" between stratified cementum and dentin of a narwhal tooth. This study highlights the graded structural, mechanical, and chemical natural characteristics of a biological interphase known as the cementum-dentin junction layer and their effect in resisting mechanical loads. From a structural perspective, light and electron microscopy techniques illustrated the layer as a wide 1000-2000 μm graded zone consisting of higher density continuous collagen fiber bundles from the surface of cementum to dentin, that parallels hygroscopic 50-100 μm wide collagenous region in human teeth. The role of collagen fibers was evident under compression testing during which the layer deformed more compared to cementum and dentin. This behavior is reflected through site-specific nanoindentation indicating a lower elastic modulus of 2.2 ± 0.5 GPa for collagen fiber bundle compared to 3 ± 0.4 GPa for mineralized regions in the layer. Similarly, microindentation technique illustrated lower hardness values of 0.36 ± 0.05 GPa, 0.33 ± 0.03 GPa, and 0.3 ± 0.07 GPa for cementum, dentin, and cementum-dentin layer, respectively. Biochemical analyses including Raman spectroscopy and synchrotron-source microprobe X-ray fluorescence demonstrated a graded composition across the interface, including a decrease in mineral-to-matrix and phosphate-to-carbonate ratios, as well as the presence of tidemark-like bands with Zn. Understanding the structure-function relationships of wider tissue interfaces can provide insights into natural tissue and organ function. © IMechE 2014.

  4. Spawning habitat associations and selection by fishes in a flow-regulated prairie river

    USGS Publications Warehouse

    Brewer, S.K.; Papoulias, D.M.; Rabeni, C.F.

    2006-01-01

    We used histological features to identify the spawning chronologies of river-dwelling populations of slenderhead darter Percina phoxocephala, suckermouth minnow Phenacobius mirabilis, stonecat Noturus flavus, and red shiner Cyprinella lutrensis and to relate their reproductive status to microhabitat associations. We identified spawning and nonspawning differences in habitat associations resulting from I year of field data via logistic regression modeling and identified shifts in microhabitat selection via frequency-of-use and availability histograms. Each species demonstrated different habitat associations between spawning and nonspawning periods. The peak spawning period for slenderhead darters was April to May in high-velocity microhabitats containing cobble. Individuals were associated with similar microhabitats during the postspawn summer and began migrating to deeper habitats in the fall. Most suckermouth minnow spawned from late March through early May in shallow microhabitats. The probability of the presence of these fish in shallow habitats declined postspawn, as fish apparently shifted to deeper habitats. Stonecats conducted prespawn activities in nearshore microhabitats containing large substrates but probably moved to deeper habitats during summer to spawn. Microhabitats with shallow depths containing cobble were associated with the presence of spawning red shiners during the summer. Prespawn fish selected low-velocity microhabitats during the spring, whereas postspawn fish selected habitats similar to the spawning habitat but added a shallow depth component. Hydraulic variables had the most influence on microhabitat models for all of these species, emphasizing the importance of flow in habitat selection by river-dwelling fishes. Histological analyses allowed us to more precisely document the time periods when habitat use is critical to species success. Without evidence demonstrating the functional mechanisms behind habitat associations, protective flows

  5. Seasonal water stress tolerance and habitat associations within four neotropical tree genera.

    PubMed

    Baraloto, Christopher; Morneau, François; Bonal, Damien; Blanc, Lilian; Ferry, Bruno

    2007-02-01

    We investigated the relationship between habitat association and physiological performance in four congeneric species pairs exhibiting contrasting distributions between seasonally flooded and terra firme habitats in lowland tropical rain forests of French Guiana, including Virola and Iryanthera (Myristicaceae), Symphonia (Clusiaceae), and Eperua (Caesalpiniaceae). We analyzed 10-year data sets of mapped and measured saplings (stems >150 cm in height and <10 cm diameter at breast height [dbh]) and trees (stems > or =10 cm dbh) across 37.5 ha of permanent plots covering a 300-ha zone, within which seasonally flooded areas (where the water table never descends below 1 m) have been mapped. Additionally, we tested the response of growth, survival, and leaf functional traits of these species to drought and flood stress in a controlled experiment. We tested for habitat preference using a modification of the torus translation method. Strong contrasting associations of the species pairs of Iryanthera, Virola, and Symphonia were observed at the sapling stage, and these associations strengthened for the tree stage. Neither species of Eperua was significantly associated with flooded habitats at the sapling stage, but E. falcata was significantly and positively associated with flooded forests at the tree stage, and trees of E. grandiflora were found almost exclusively in nonflooded habitats. Differential performance provided limited explanatory support for the observed habitat associations, with only congeners of Iryanthera exhibiting divergent sapling survival and tree growth. Seedlings of species associated with flooded forest tended to have higher photosynthetic capacity than their congeners at field capacity. In addition, they tended to have the largest reductions in leaf gas exchange and growth rate in response to experimental drought stress and the least reductions in response to experimental inundation. The corroboration of habitat association with differences in

  6. Habitat associations of juvenile Burbot in a tributary of the Kootenai River

    USGS Publications Warehouse

    Beard, Zachary S.; Quist, Michael C.; Hardy, Ryan S.; Ross, Tyler J.

    2017-01-01

    Burbot Lota lota in the lower Kootenai River, Idaho, have been the focus of extensive conservation efforts, particularly conservation aquaculture. One of the primary management strategies has been the release of Burbot into small tributaries in the Kootenai River basin, such as Deep Creek. Since 2012, approximately 12,000 juvenile Burbot have been stocked into Deep Creek; however, little is known about the habitat use of stocked Burbot. The objective of this study was to evaluate habitat associations of juvenile Burbot in Deep Creek. Fish and habitat were sampled from 58 reaches of the creek. Regression models suggested that Burbot moved little after stocking and were associated with areas of high mean depth and coarse substrate. This study provides additional knowledge on habitat associations of juvenile Burbot and suggests that managers should consider selecting deep habitats with coarse substrate for stocking locations.

  7. Pervasive Local-Scale Tree-Soil Habitat Association in a Tropical Forest Community.

    PubMed

    Allié, Elodie; Pélissier, Raphaël; Engel, Julien; Petronelli, Pascal; Freycon, Vincent; Deblauwe, Vincent; Soucémarianadin, Laure; Weigel, Jean; Baraloto, Christopher

    2015-01-01

    We examined tree-soil habitat associations in lowland forest communities at Paracou, French Guiana. We analyzed a large dataset assembling six permanent plots totaling 37.5 ha, in which extensive LIDAR-derived topographical data and soil chemical and physical data have been integrated with precise botanical determinations. Map of relative elevation from the nearest stream summarized both soil fertility and hydromorphic characteristics, with seasonally inundated bottomlands having higher soil phosphate content and base saturation, and plateaus having higher soil carbon, nitrogen and aluminum contents. We employed a statistical test of correlations between tree species density and environmental maps, by generating Monte Carlo simulations of random raster images that preserve autocorrelation of the original maps. Nearly three fourths of the 94 taxa with at least one stem per ha showed a significant correlation between tree density and relative elevation, revealing contrasted species-habitat associations in term of abundance, with seasonally inundated bottomlands (24.5% of species) and well-drained plateaus (48.9% of species). We also observed species preferences for environments with or without steep slopes (13.8% and 10.6%, respectively). We observed that closely-related species were frequently associated with different soil habitats in this region (70% of the 14 genera with congeneric species that have a significant association test) suggesting species-habitat associations have arisen multiple times in this tree community. We also tested if species with similar habitat preferences shared functional strategies. We found that seasonally inundated forest specialists tended to have smaller stature (maximum diameter) than species found on plateaus. Our results underline the importance of tree-soil habitat associations in structuring diverse communities at fine spatial scales and suggest that additional studies are needed to disentangle community assembly mechanisms

  8. Pervasive Local-Scale Tree-Soil Habitat Association in a Tropical Forest Community

    PubMed Central

    Allié, Elodie; Pélissier, Raphaël; Engel, Julien; Petronelli, Pascal; Freycon, Vincent; Deblauwe, Vincent; Soucémarianadin, Laure; Weigel, Jean; Baraloto, Christopher

    2015-01-01

    We examined tree-soil habitat associations in lowland forest communities at Paracou, French Guiana. We analyzed a large dataset assembling six permanent plots totaling 37.5 ha, in which extensive LIDAR-derived topographical data and soil chemical and physical data have been integrated with precise botanical determinations. Map of relative elevation from the nearest stream summarized both soil fertility and hydromorphic characteristics, with seasonally inundated bottomlands having higher soil phosphate content and base saturation, and plateaus having higher soil carbon, nitrogen and aluminum contents. We employed a statistical test of correlations between tree species density and environmental maps, by generating Monte Carlo simulations of random raster images that preserve autocorrelation of the original maps. Nearly three fourths of the 94 taxa with at least one stem per ha showed a significant correlation between tree density and relative elevation, revealing contrasted species-habitat associations in term of abundance, with seasonally inundated bottomlands (24.5% of species) and well-drained plateaus (48.9% of species). We also observed species preferences for environments with or without steep slopes (13.8% and 10.6%, respectively). We observed that closely-related species were frequently associated with different soil habitats in this region (70% of the 14 genera with congeneric species that have a significant association test) suggesting species-habitat associations have arisen multiple times in this tree community. We also tested if species with similar habitat preferences shared functional strategies. We found that seasonally inundated forest specialists tended to have smaller stature (maximum diameter) than species found on plateaus. Our results underline the importance of tree-soil habitat associations in structuring diverse communities at fine spatial scales and suggest that additional studies are needed to disentangle community assembly mechanisms

  9. Habitat associations of migrating and overwintering grassland birds in southern Texas

    USGS Publications Warehouse

    Igl, L.D.; Ballard, B.M.

    1999-01-01

    We report on the habitat associations of 21 species of grassland birds overwintering in or migrating through southern Texas, during 1991-1992 and 1992-1993. Ninety percent of our grassland bird observations were made during winter and spring, and only 10% occurred during fall. Grassland species made up a high proportion of the total bird densities in grassland and shrub-grassland habitats, but much lower proportions in the habitats with more woody vegetation. Fewer grassland species were observed in grassland and woodland than in brushland, parkland, and shrub-grassland habitats. Grassland birds generally were found in higher densities in habitats that had woody canopy coverage of < 30%; densities of grassland birds were highest in shrub-grassland habitat and lowest in woodland habitat. Species that are grassland specialists on their breeding grounds tended to be more habitat specific during the nonbreeding season compared to shrub-grassland specialists, which were more general in their nonbreeding-habitat usage. Nonetheless, our data demonstrate that grassland birds occur in a variety of habitats during the nonbreeding season and seem to occupy a broader range of habitats than previously described.

  10. Habitat associations of migrating and overwintering grassland birds in Southern Texas

    USGS Publications Warehouse

    Igl, Lawrence D.; Ballard, Bart M.

    1999-01-01

    We report on the habitat associations of 21 species of grassland birds overwintering in or migrating through southern Texas, during 1991-1992 and 1992-1993. Ninety percent of our grassland bird observations were made during winter and spring, and only 10% occurred during fall. Grassland species made up a high proportion of the total bird densities in grassland and shrub-grassland habitats, but much lower proportions in the habitats with more woody vegetation. Fewer grassland species were observed in grassland and woodland than in brushland, parkland, and shrub-grassland habitats. Grassland birds generally were found in higher densities in habitats that had woody canopy coverage of < 30%; densities of grassland birds were highest in shrub-grassland habitat and lowest in woodland habitat. Species that are grassland specialists on their breeding grounds tended to be more habitat specific during the nonbreeding season compared to shrub-grassland specialists, which were more general in their nonbreeding-habitat usage. Nonetheless, our data demonstrate that grassland birds occur in a variety of habitats during the nonbreeding season and seem to occupy a broader range of habitats than previously described.

  11. Habitat conditions associated with lynx hunting behavior during winter in northern Washington

    Treesearch

    Benjamin T. Maletzke; Gary M. Koehler; Robert B. Wielgus; Keith B. Aubry; Marc A. Evans

    2008-01-01

    Effectively managing habitat for threatened populations of Canada lynx (Lynx canadensis) requires knowledge of habitat conditions that provide for the ecological needs of lynx. We snow-tracked lynx to identify habitat conditions associated with hunting behavior and predation during winters of 2002-2003 and 2003-2004 in the northern Cascade Range in...

  12. A global analysis of bird plumage patterns reveals no association between habitat and camouflage

    PubMed Central

    Marshall, Kate L.A.; Gluckman, Thanh-Lan

    2016-01-01

    Evidence suggests that animal patterns (motifs) function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types—mottled (irregular), scales, bars and spots (regular)—and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species’ geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world’s birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world’s eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis. PMID:27867762

  13. A global analysis of bird plumage patterns reveals no association between habitat and camouflage.

    PubMed

    Somveille, Marius; Marshall, Kate L A; Gluckman, Thanh-Lan

    2016-01-01

    Evidence suggests that animal patterns (motifs) function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types-mottled (irregular), scales, bars and spots (regular)-and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species' geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world's birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world's eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.

  14. Transferability of habitat suitability models for nesting woodpeckers associated with wildfire

    Treesearch

    Quresh S. Latif; Vicki Saab; Jeff P. Hollenbeck; Jonathan G. Dudley

    2016-01-01

    Following wildfire, forest managers are challenged with meeting both socioeconomic demands (e.g., salvage logging) and mandates requiring habitat conservation for disturbance-associated wildlife (e.g., woodpeckers). Habitat suitability models for nesting woodpeckers can be informative, but tests of model transferability are needed to understand how broadly...

  15. Winter habitat associations of diurnal raptors in Californias Central Valley

    USGS Publications Warehouse

    Pandolrno, E.R.; Herzog, M.P.; Hooper, S.L.; Smith, Z.

    2011-01-01

    The wintering raptors of California's Central Valley are abundant and diverse. Despite this, little information exists on the habitats used by these birds in winter. We recorded diurnal raptors along 19 roadside survey routes throughout the Central Valley for three consecutive winters between 2007 and 2010. We obtained data sufficient to determine significant positive and negative habitat associations for the White-tailed Kite (Elanus leucurus), Bald Eagle {Haliaeetus leucocephalus), Northern Harrier (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Ferruginous Hawk (Buteo regalis), Rough-legged Hawk (Buteo lagopus), American Kestrel (Falco sparverius), and Prairie Falcon (Falco mexicanus). The Prairie Falcon and Ferruginous and Rough-legged hawks showed expected strong positive associations with grasslands. The Bald Eagle and Northern Harrier were positively associated not only with wetlands but also with rice. The strongest positive association for the White-tailed Kite was with wetlands. The Red-tailed Hawk was positively associated with a variety of habitat types but most strongly with wetlands and rice. The American Kestrel, Northern Harrier, and White-tailed Kite were positively associated with alfalfa. Nearly all species were negatively associated with urbanized landscapes, orchards, and other intensive forms of agriculture. The White-tailed Kite, Northern Harrier, Redtailed Hawk, Ferruginous Hawk, and American Kestrel showed significant negative associations with oak savanna. Given the rapid conversion of the Central Valley to urban and intensive agricultural uses over the past few decades, these results have important implications for conservation of these wintering raptors in this region.

  16. Large-scale habitat associations of four desert anurans in Big Bend National Park, Texas

    USGS Publications Warehouse

    Dayton, Gage H.; Jung, R.E.; Droege, S.

    2004-01-01

    We used night driving to examine large scale habitat associations of four common desert anurans in Big Bend National Park, Texas. We examined association of soil types and vegetation communities with abundance of Couch's Spadefoots (Scaphiopus couchii), Red-spotted Toads (Bufo punctatus), Texas Toads (Bufo speciosus), and Western Green Toads (Bufo debilis). All four species were disproportionately associated with frequently inundated soils that are relatively high in clay content. Bufo punctatus was associated with rocky soil types more frequently than the other three species. Association between all four species and vegetation types was disproportionate in relation to availability. Bufo debilis and Bufo punctatus were associated with creosote and mixed scrub vegetation. Bufo speciosus and Scaphiopus couchii were associated with mesquite scrub vegetation. Bufo debilis, Scaphiopus couchii, and B. speciosus were more tightly associated with specific habitat types, whereas B. punctatus exhibited a broader distribution across the habitat categories. Examining associations between large-scale habitat categories and species abundance is an important first step in understanding factors that influence species distributions and presence-absence across the landscape.

  17. Cyanobacteria associated with Anopheles albimanus (Diptera: Culicidae) larval habitats in southern Mexico.

    PubMed

    Vázquez-Martínez, M Guadalupe; Rodríguez, Mario H; Arredondo-Jiménez, Juan I; Méndez-Sanchez, José D; Bond-Compeán, J Guillermo; Cold-Morgan, Michelle

    2002-11-01

    Cyanobacteria associated with Anopheles albimanus Wiedemann larval habitats from southern Chiapas, Mexico, were isolated and identified from water samples and larval midguts using selective medium BG-11. Larval breeding sites were classified according to their hydrology and dominant vegetation. Cyanobacteria isolated in water samples were recorded and analyzed according to hydrological and vegetation habitat breeding types, and mosquito larval abundance. In total, 19 cyanobacteria species were isolated from water samples. Overall, the most frequently isolated cyanobacterial taxa were Phormidium sp., Oscillatoria sp., Aphanocapsa cf. littoralis, Lyngbya lutea, P. animalis, and Anabaena cf. spiroides. Cyanobacteria were especially abundant in estuaries, irrigation canals, river margins and mangrove lagoons, and more cyanobacteria were isolated from Brachiaria mutica, Ceratophyllum demersum, and Hymenachne amplexicaulis habitats. Cyanobacteria were found in habitats with low to high An. albimanus larval abundance, but Aphanocapsa cf. littoralis was associated with habitats of low larval abundance. No correlation was found between water chemistry parameters and the presence of cyanobacteria, however, water temperature (29.2-29.4 degrees C) and phosphate concentration (79.8-136.5 ppb) were associated with medium and high mosquito larvae abundance. In An. albimanus larval midguts, only six species of cyanobacteria were isolated, the majority being from the most abundant cyanobacteria in water samples.

  18. Sex-related differences in habitat associations of wintering American Kestrels in California's Central Valley

    USGS Publications Warehouse

    Pandolfino, E.R.; Herzog, M.P.; Smith, Z.

    2011-01-01

    We used roadside survey data collected from 19 routes over three consecutive winters from 200708 to 200910 to compare habitat associations of male and female American Kestrels (Falco sparverius) in the Central Valley of California to determine if segregation by sex was evident across this region. As a species, American Kestrels showed positive associations with alfalfa and other forage crops like hay and winter wheat, as well as grassland, irrigated pasture, and rice. Habitat associations of females were similar, with female densities in all these habitats except rice significantly higher than average. Male American Kestrels showed a positive association only with grassland and were present at densities well below those of females in alfalfa, other forage crops, and grassland. Males were present in higher densities than females in most habitats with negative associations for the species, such as orchards, urbanized areas, and oak savannah. The ratio of females to males for each route was positively correlated with the overall density of American Kestrels on that route. Our findings that females seem to occupy higher quality habitats in winter are consistent with observations from elsewhere in North America. ?? 2011 The Raptor Research Foundation, Inc.

  19. Avifauna in southern California chaparral: seasonal distribution, habitat association, reproductive phenology

    Treesearch

    William O. Wirtz

    1991-01-01

    Dates were obtained between February 1969 and October 1979 on the seasonal occurrence, habitat association, reproductive phenology, and relative abundance of avifauna at two study sites in the chaparral community of the San Gabriel Mountains of southern California. The purpose of the study was to collect information on bird species use of this habitat and to document...

  20. Breeding habitat associations and predicted distribution of an obligate tundra-breeding bird, Smith's Longspur

    USGS Publications Warehouse

    Wild, Teri C.; Kendall, Steven J.; Guldager, Nikki; Powell, Abby N.

    2015-01-01

    Smith's Longspur (Calcarius pictus) is a species of conservation concern which breeds in Arctic habitats that are expected to be especially vulnerable to climate change. We used bird presence and habitat data from point-transect surveys conducted at 12 sites across the Brooks Range, Alaska, 2003–2009, to identify breeding areas, describe local habitat associations, and identify suitable habitat using a predictive model of Smith's Longspur distribution. Smith's Longspurs were observed at seven sites, where they were associated with a variety of sedge–shrub habitats composed primarily of mosses, sedges, tussocks, and dwarf shrubs; erect shrubs were common but sparse. Nonmetric multidimensional scaling ordination of ground cover revealed positive associations of Smith's Longspur presence with sedges and mosses and a negative association with high cover of shrubs. To model predicted distribution, we used boosted regression trees to relate landscape variables to occurrence. Our model predicted that Smith's Longspurs may occur in valleys and foothills of the northeastern and southeastern mountains and in upland plateaus of the western mountains, and farther west than currently documented, over a predicted area no larger than 15% of the Brooks Range. With climate change, shrubs are expected to grow larger and denser, while soil moisture and moss cover are predicted to decrease. These changes may reduce Smith's Longspur habitat quality and limit distribution in the Brooks Range to poorly drained lowlands and alpine plateaus where sedge–shrub tundra is likely to persist. Conversely, northward advance of shrubs into sedge tundra may create suitable habitat, thus supporting a northward longspur distribution shift.

  1. Habitat associations of species show consistent but weak responses to climate

    PubMed Central

    Suggitt, Andrew J.; Stefanescu, Constantí; Páramo, Ferran; Oliver, Tom; Anderson, Barbara J.; Hill, Jane K.; Roy, David B.; Brereton, Tom; Thomas, Chris D.

    2012-01-01

    Different vegetation types can generate variation in microclimates at local scales, potentially buffering species from adverse climates. To determine if species could respond to such microclimates under climatic warming, we evaluated whether ectothermic species (butterflies) can exploit favourable microclimates and alter their use of different habitats in response to year-to-year variation in climate. In both relatively cold (Britain) and warm (Catalonia) regions of their geographical ranges, most species shifted into cooler, closed habitats (e.g. woodland) in hot years, and into warmer, open habitats (e.g. grassland) in cooler years. Additionally, three-quarters of species occurred in closed habitats more frequently in the warm region than in the cool region. Thus, species shift their local distributions and alter their habitat associations to exploit favourable microclimates, although the magnitude of the shift (approx. 1.3% of individuals from open to shade, per degree Celsius) is unlikely to buffer species from impacts of regional climate warming. PMID:22491762

  2. Habitat associations of chorusing anurans in the Lower Mississippi River Alluvial valley

    USGS Publications Warehouse

    Lichtenberg, J.S.; King, S.L.; Grace, J.B.; Walls, S.C.

    2006-01-01

    Amphibian populations have declined worldwide. To pursue conservation efforts adequately, land managers need more information concerning amphibian habitat requirements. To address this need, we examined relationships between anurans and habitat characteristics of wetlands in the Lower Mississippi River Alluvial Valley (LMAV). We surveyed chorusing anurans in 31 wetlands in 2000 and 28 wetlands in 2001, and measured microhabitat variables along the shoreline within the week following each survey. We recorded 12 species of anurans during our study. Species richness was significantly lower in 2000 than 2001 (t-test, P < 0.001) and correlated with an ongoing drought. We found species richness to be significantly greater at lake sites compared to impoundment, swale, and riverine sites (ANOVA, P = 0.002). We used stepwise regression to investigate the wetland types and microhabitat characteristics associated with species richness of chorusing anurans. Microhabitat characteristics associated with species richness included dense herbaceous vegetation and accumulated litter along the shoreline. Individual species showed species-specific habitat associations. The bronze frog, American bullfrog, and northern cricket frog were positively associated with lake sites (Fisher's Exact Test, P < 0.05), however wetland type did not significantly influence any additional species. Using bivariate correlations, we found that six of the seven most common species had significant associations with microhabitat variables. Overall, our findings support the view that conservation and enhancement of amphibian communities in the LMAV and elsewhere requires a matrix of diverse wetland types and habitat conditions. ?? 2006, The Society of Wetland Scientists.

  3. Associations of Dragonflies (Odonata) to Habitat Variables within the Maltese Islands: A Spatio-Temporal Approach

    PubMed Central

    Balzan, Mario V.

    2012-01-01

    Relatively little information is available on environmental associations and the conservation of Odonata in the Maltese Islands. Aquatic habitats are normally spatio-temporally restricted, often located within predominantly rural landscapes, and are thereby susceptible to farmland water management practices, which may create additional pressure on water resources. This study investigates how odonate assemblage structure and diversity are associated with habitat variables of local breeding habitats and the surrounding agricultural landscapes. Standardized survey methodology for adult Odonata involved periodical counts over selected water-bodies (valley systems, semi-natural ponds, constructed agricultural reservoirs). Habitat variables relating to the type of water body, the floristic and physiognomic characteristics of vegetation, and the composition of the surrounding landscape, were studied and analyzed through a multivariate approach. Overall, odonate diversity was associated with a range of factors across multiple spatial scales, and was found to vary with time. Lentic water-bodies are probably of high conservation value, given that larval stages were mainly associated with this habitat category, and that all species were recorded in the adult stage in this habitat type. Comparatively, lentic and lotic seminatural waterbodies were more diverse than agricultural reservoirs and brackish habitats. Overall, different odonate groups were associated with different vegetation life-forms and height categories. The presence of the great reed, Arundo donax L., an invasive alien species that forms dense stands along several water-bodies within the Islands, seems to influence the abundance and/or occurrence of a number of species. At the landscape scale, roads and other ecologically disturbed ground, surface water-bodies, and landscape diversity were associated with particular components of the odonate assemblages. Findings from this study have several implications for the

  4. Associations of dragonflies (Odonata) to habitat variables within the Maltese Islands: a spatio-temporal approach.

    PubMed

    Balzan, Mario V

    2012-01-01

    Relatively little information is available on environmental associations and the conservation of Odonata in the Maltese Islands. Aquatic habitats are normally spatio-temporally restricted, often located within predominantly rural landscapes, and are thereby susceptible to farmland water management practices, which may create additional pressure on water resources. This study investigates how odonate assemblage structure and diversity are associated with habitat variables of local breeding habitats and the surrounding agricultural landscapes. Standardized survey methodology for adult Odonata involved periodical counts over selected water-bodies (valley systems, semi-natural ponds, constructed agricultural reservoirs). Habitat variables relating to the type of water body, the floristic and physiognomic characteristics of vegetation, and the composition of the surrounding landscape, were studied and analyzed through a multivariate approach. Overall, odonate diversity was associated with a range of factors across multiple spatial scales, and was found to vary with time. Lentic water-bodies are probably of high conservation value, given that larval stages were mainly associated with this habitat category, and that all species were recorded in the adult stage in this habitat type. Comparatively, lentic and lotic seminatural waterbodies were more diverse than agricultural reservoirs and brackish habitats. Overall, different odonate groups were associated with different vegetation life-forms and height categories. The presence of the great reed, Arundo donax L., an invasive alien species that forms dense stands along several water-bodies within the Islands, seems to influence the abundance and/or occurrence of a number of species. At the landscape scale, roads and other ecologically disturbed ground, surface water-bodies, and landscape diversity were associated with particular components of the odonate assemblages. Findings from this study have several implications for the

  5. CONTRASTING HABITAT ASSOCIATIONS OF SAGEBRUSH-STEPPE SONGBIRDS IN THE INTERMOUNTAIN WEST

    PubMed Central

    MILLER, ROBERT A.; BOND, LAURA; MIGAS, PATRICK N.; CARLISLE, JAY D.; KALTENECKER, GREGORY S.

    2017-01-01

    Sagebrush (Artemisia spp.) steppe is one of North America’s most imperiled ecosystems, as the result of many factors including grazing, development, fire, and invasion of exotic plants. Threats to sagebrush steppe are expected to increase because of climate change and further human development. Many songbirds use sagebrush steppe opportunistically, but a few obligate species are dependent on it. To quantify the habitat associations of three sagebrush obligates, the Sage Thrasher (Oreoscoptes montanus), Sagebrush Sparrow (Artemisiospiza nevadensis), and Brewer’s Sparrow (Spizella breweri), and nine other songbird species that use this habitat, we surveyed across a broad region of Idaho. At each of 104 sites, we selected three plots, one each in relatively poor, moderate, and good condition, defined qualitatively by the cover of native shrubs. We quantified bird abundance by point counts, described the habitat at these points by a line-intercept method, and at each plot calculated the fraction of a circle (radius 1 km) covered in shrubs or grassland. We compared two-scale occupancy models based on these data by the information-theoretic approach. According to the models, our qualitative assessment of habitat condition within a site distinguished birds’ use of relatively good habitat from their use of poor habitats only, not from those in moderate condition. Thus the sagebrush-obligate species may tolerate some local habitat degradation, at least up to some unidentified threshold. Occurrence of all three sagebrush obligates correlated well with one or more characteristics of sagebrush such as its cover, height, or heterogeneity in height. They differed in the Sage Thrasher being most sensitive to sagebrush cover, the Sagebrush Sparrow being found more often at lower elevations, and the Brewer’s Sparrow being less sensitive to ground cover. The nine other species evaluated were less or negatively associated with attributes of sagebrush. On the basis of these

  6. Habitat and host associations of Craterellus tubaeformis in northwestern Oregon.

    Treesearch

    M.J. Trappe

    2004-01-01

    Knowledge of the habitat and host associations of Craterellus tubaeformis (winter chanterelle) is the key to understanding the ecological characteristics needed for its conservation. In this study, a survey of forest types in northwestern Oregon for mycorrhizal associates is performed and the hypotheses that stand age and the volume of well-decayed...

  7. Soundscapes and Larval Settlement: Larval Bivalve Responses to Habitat-Associated Underwater Sounds.

    PubMed

    Eggleston, David B; Lillis, Ashlee; Bohnenstiehl, DelWayne R

    2016-01-01

    We quantified the effects of habitat-associated sounds on the settlement response of two species of bivalves with contrasting habitat preferences: (1) Crassostrea virginicia (oyster), which prefers to settle on other oysters, and (2) Mercenaria mercenaria (clam), which settles on unstructured habitats. Oyster larval settlement in the laboratory was significantly higher when exposed to oyster reef sound compared with either off-reef or no-sound treatments. Clam larval settlement did not vary according to sound treatments. Similar to laboratory results, field experiments showed that oyster larval settlement in "larval housings" suspended above oyster reefs was significantly higher compared with off-reef sites.

  8. Oyster Larvae Settle in Response to Habitat-Associated Underwater Sounds

    PubMed Central

    Lillis, Ashlee; Eggleston, David B.; Bohnenstiehl, DelWayne R.

    2013-01-01

    Following a planktonic dispersal period of days to months, the larvae of benthic marine organisms must locate suitable seafloor habitat in which to settle and metamorphose. For animals that are sessile or sedentary as adults, settlement onto substrates that are adequate for survival and reproduction is particularly critical, yet represents a challenge since patchily distributed settlement sites may be difficult to find along a coast or within an estuary. Recent studies have demonstrated that the underwater soundscape, the distinct sounds that emanate from habitats and contain information about their biological and physical characteristics, may serve as broad-scale environmental cue for marine larvae to find satisfactory settlement sites. Here, we contrast the acoustic characteristics of oyster reef and off-reef soft bottoms, and investigate the effect of habitat-associated estuarine sound on the settlement patterns of an economically and ecologically important reef-building bivalve, the Eastern oyster (Crassostrea virginica). Subtidal oyster reefs in coastal North Carolina, USA show distinct acoustic signatures compared to adjacent off-reef soft bottom habitats, characterized by consistently higher levels of sound in the 1.5–20 kHz range. Manipulative laboratory playback experiments found increased settlement in larval oyster cultures exposed to oyster reef sound compared to unstructured soft bottom sound or no sound treatments. In field experiments, ambient reef sound produced higher levels of oyster settlement in larval cultures than did off-reef sound treatments. The results suggest that oyster larvae have the ability to respond to sounds indicative of optimal settlement sites, and this is the first evidence that habitat-related differences in estuarine sounds influence the settlement of a mollusk. Habitat-specific sound characteristics may represent an important settlement and habitat selection cue for estuarine invertebrates and could play a role in driving

  9. Oyster larvae settle in response to habitat-associated underwater sounds.

    PubMed

    Lillis, Ashlee; Eggleston, David B; Bohnenstiehl, DelWayne R

    2013-01-01

    Following a planktonic dispersal period of days to months, the larvae of benthic marine organisms must locate suitable seafloor habitat in which to settle and metamorphose. For animals that are sessile or sedentary as adults, settlement onto substrates that are adequate for survival and reproduction is particularly critical, yet represents a challenge since patchily distributed settlement sites may be difficult to find along a coast or within an estuary. Recent studies have demonstrated that the underwater soundscape, the distinct sounds that emanate from habitats and contain information about their biological and physical characteristics, may serve as broad-scale environmental cue for marine larvae to find satisfactory settlement sites. Here, we contrast the acoustic characteristics of oyster reef and off-reef soft bottoms, and investigate the effect of habitat-associated estuarine sound on the settlement patterns of an economically and ecologically important reef-building bivalve, the Eastern oyster (Crassostrea virginica). Subtidal oyster reefs in coastal North Carolina, USA show distinct acoustic signatures compared to adjacent off-reef soft bottom habitats, characterized by consistently higher levels of sound in the 1.5-20 kHz range. Manipulative laboratory playback experiments found increased settlement in larval oyster cultures exposed to oyster reef sound compared to unstructured soft bottom sound or no sound treatments. In field experiments, ambient reef sound produced higher levels of oyster settlement in larval cultures than did off-reef sound treatments. The results suggest that oyster larvae have the ability to respond to sounds indicative of optimal settlement sites, and this is the first evidence that habitat-related differences in estuarine sounds influence the settlement of a mollusk. Habitat-specific sound characteristics may represent an important settlement and habitat selection cue for estuarine invertebrates and could play a role in driving

  10. Habitat associations of bats in south-central West Virginia

    Treesearch

    Michael R. Schirmacher; Steven B. Castleberry; W. Mark Ford; Karl V. Miller

    2007-01-01

    We conducted acoustic surveys at National Park Service and state park properties in south-central West Virginia to create bat habitat association models across a large, topographically complex and relatively intact Appalachian Hardwood landscape representative of the Allegheny Plateau portion of the central Appalachians. We developed generalized and species-specific...

  11. Habitat associations and distribution of the hyperbenthic shrimp, Nauticaris marionis, around the sub-Antarctic Prince Edward Islands

    NASA Astrophysics Data System (ADS)

    Haley, Craig; von der Meden, Charles; Atkinson, Lara; Reed, Cecile

    2017-09-01

    The association of organisms with particular habitats and habitat-forming organisms, can strongly influence species distributions, interactions and wider ecosystem services. At the sub-Antarctic Prince Edward Islands, the caridean shrimp Nauticaris marionis is a principal part of the benthic ecosystem, occurring between ca. 50 m and 600 m. Its role as a trophic link between the primary productivity and higher predators is established, but little is understood of its in situ habitat usage and associations or of how these structure patterns of abundance. We investigated these aspects directly using a benthic camera sled, sampling 27 stations between 50 m and 500 m. Substratum type was characterised, and estimates of percentage cover of the 13 main groups of habitat-forming epibenthic taxa were made, alongside absolute counts of N. marionis within 'digital quadrats' drawn from 300 m transects. The distribution of N. marionis was influenced by depth, substratum type and overall biogenic cover, being limited to habitats between 50 and 160 m depth on mud or gravel substrata only, and having > 50% biogenic cover. The presence/absence of N. marionis related to significantly different epibenthic assemblages (termed biogenic habitats), but this effect was contingent on depth. Likewise, densities of N. marionis were significantly affected by biogenic habitat type, identifying an association with two biogenic habitat groups, one dominated by red-algae, the other by structurally complex bryozoan species. These associations likely relate to the structural complexity of the two habitat groups, rather than the specific taxa involved. The apparent absence of N. marionis at depths > 160 m contrasts with earlier records and poses questions about the trophic importance of the shrimp in deeper habitats.

  12. Macrofaunal communities associated with chemosynthetic habitats from the U.S. Atlantic margin: A comparison among depth and habitat types

    USGS Publications Warehouse

    Bourque, Jill R.; Robertson, Craig M.; Brooke, Sandra; Demopoulos, Amanda W.J.

    2016-01-01

    Hydrocarbon seeps support distinct benthic communities capable of tolerating extreme environmental conditions and utilizing reduced chemical compounds for nutrition. In recent years, several locations of methane seepage have been mapped along the U.S. Atlantic continental slope. In 2012 and 2013, two newly discovered seeps were investigated in this region: a shallow site near Baltimore Canyon (BCS, 366–412 m) and a deep site near Norfolk Canyon (NCS, 1467–1602 m), with both sites containing extensive chemosynthetic mussel bed and microbial mat habitats. Sediment push cores, suction samples, and Ekman box cores were collected to quantify the abundance, diversity, and community structure of benthic macrofauna (>300 μm) in mussel beds, mats, and slope habitats at both sites. Community data from the deep site were also assessed in relation to the associated sediment environment (organic carbon and nitrogen, stable carbon and nitrogen isotopes, grain size, and depth). Infaunal assemblages and densities differed both between depths and among habitat types. Macrofaunal densities in microbial mats were four times greater than those present in mussel beds and slope sediments and were dominated by the annelid families Dorvilleidae, Capitellidae, and Tubificidae, while mussel habitats had higher proportions of crustaceans. Diversity was lower in BCS microbial mat habitats, but higher in mussel and slope sediments compared to NCS habitats. Multivariate statistical analysis revealed specific sediment properties as important for distinguishing the macrofaunal communities, including larger grain sizes present within NCS microbial mat habitats and depleted stable carbon isotopes (δ13C) in sediments present at mussel beds. These results suggest that habitat differences in the quality and source of organic matter are driving the observed patterns in the infaunal assemblages, including high β diversity and high variability in the macrofaunal community composition. This

  13. Macrofaunal communities associated with chemosynthetic habitats from the U.S. Atlantic margin: A comparison among depth and habitat types

    NASA Astrophysics Data System (ADS)

    Bourque, Jill R.; Robertson, Craig M.; Brooke, Sandra; Demopoulos, Amanda W. J.

    2017-03-01

    Hydrocarbon seeps support distinct benthic communities capable of tolerating extreme environmental conditions and utilizing reduced chemical compounds for nutrition. In recent years, several locations of methane seepage have been mapped along the U.S. Atlantic continental slope. In 2012 and 2013, two newly discovered seeps were investigated in this region: a shallow site near Baltimore Canyon (BCS, 366-412 m) and a deep site near Norfolk Canyon (NCS, 1467-1602 m), with both sites containing extensive chemosynthetic mussel bed and microbial mat habitats. Sediment push cores, suction samples, and Ekman box cores were collected to quantify the abundance, diversity, and community structure of benthic macrofauna (>300 μm) in mussel beds, mats, and slope habitats at both sites. Community data from the deep site were also assessed in relation to the associated sediment environment (organic carbon and nitrogen, stable carbon and nitrogen isotopes, grain size, and depth). Infaunal assemblages and densities differed both between depths and among habitat types. Macrofaunal densities in microbial mats were four times greater than those present in mussel beds and slope sediments and were dominated by the annelid families Dorvilleidae, Capitellidae, and Tubificidae, while mussel habitats had higher proportions of crustaceans. Diversity was lower in BCS microbial mat habitats, but higher in mussel and slope sediments compared to NCS habitats. Multivariate statistical analysis revealed specific sediment properties as important for distinguishing the macrofaunal communities, including larger grain sizes present within NCS microbial mat habitats and depleted stable carbon isotopes (δ13C) in sediments present at mussel beds. These results suggest that habitat differences in the quality and source of organic matter are driving the observed patterns in the infaunal assemblages, including high β diversity and high variability in the macrofaunal community composition. This study is

  14. Nearshore habitat and fish community associations of coaster brook trout in Isle Royale, Lake Superior

    USGS Publications Warehouse

    Gorman, O.T.; Moore, S.A.; Carlson, A.J.; Quinlan, H.R.

    2008-01-01

    We characterized the nearshore habitat and fish community composition of approximately 300 km of shoreline within and adjacent to the major embayments of Isle Royale, Lake Superior. Sampling yielded 17 species, of which 12 were widespread and represented a common element of the Lake Superior fish community, including cisco Coregonus artedi, lake whitefish C. clupeaformis, round whitefish Prosopium cylindraceum, lake trout Salvelinus namaycush, rainbow smelt Osmerus mordax, lake chub Couesius plumbeus, longnose sucker Catostomus catostomus, white sucker C. commersonii, trout-perch Percopsis omiscomaycus, ninespine stickleback Pungitius pungitius, burbot Lota lota, and slimy sculpin Cottus cognatus. The presence of brook trout S. fontinalis in an embayment was associated with the common species of the Isle Royale nearshore fish community, particularly cisco, longnose sucker, and round whitefish. However, brook trout were present in only five embayments and were common only in Tobin Harbor. Most Isle Royale embayments had broadly overlapping ranges of nearshore habitats. Within embayments, fish were distributed along a habitat gradient from less-protected rocky habitat near the mouth to highly protected habitat with mixed and finer substrates at the head. Embayments with brook trout had greater mean protection from the open lake, greater variation in depth, greater mean cover, and higher mean frequencies of large substrates (cobble, boulder, and bedrock). Within those embayments, brook trout were associated with habitat patches with higher mean frequencies of small substrates (particularly sand and coarse gravel). Within Tobin Harbor, brook trout were associated with midembayment habitat and species assemblages, especially those locations with a mixture of sand, gravel, and cobble substrates, an absence of bedrock, and the presence of round whitefish, white sucker, and trout-perch. Comparison of embayments with the model, Tobin Harbor, showed that six embayments

  15. Spatial data for Eurycea salamander habitats associated With three aquifers in south-central Texas

    USGS Publications Warehouse

    Heitmuller, Franklin T.; Reece, Brian D.

    2006-01-01

    Eurycea salamander taxa comprise 12 known species that inhabit springs and caves in south-central Texas. Many of these are threatened or endangered species, and some are found only at one location. A number of the neotenic salamanders might be at risk from habitat loss associated with declines in ground-water levels. Eurycea salamander habitats are associated with three aquifers in south-central Texas: (1) the Edwards-Trinity (Plateau) aquifer, (2) the Edwards (Balcones Fault Zone) aquifer, and (3) the Trinity aquifer. The Edwards (Balcones fault zone) aquifer is commonly separated into three segments: from southwest to northeast, the San Antonio segment, the Barton Springs segment, and the northern segment. The Trinity aquifer south of the Colorado River can be divided into three permeable zones, the upper, middle, and lower zone. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, developed this report (geodatabase) to aggregate the spatial data necessary to assess the potential effects of ground-water declines on known Eurycea habitat locations in south-central Texas. The geodatabase provides information about spring habitats, spring flow, cave habitats, aquifers, and projected water levels.

  16. Marine fish community structure and habitat associations on the Canadian Beaufort shelf and slope

    NASA Astrophysics Data System (ADS)

    Majewski, Andrew R.; Atchison, Sheila; MacPhee, Shannon; Eert, Jane; Niemi, Andrea; Michel, Christine; Reist, James D.

    2017-03-01

    Marine fishes in the Canadian Beaufort Sea have complex interactions with habitats and prey, and occupy a pivotal position in the food web by transferring energy between lower- and upper-trophic levels, and also within and among habitats (e.g., benthic-pelagic coupling). The distributions, habitat associations, and community structure of most Beaufort Sea marine fishes, however, are unknown thus precluding effective regulatory management of emerging offshore industries in the region (e.g., hydrocarbon development, shipping, and fisheries). Between 2012 and 2014, Fisheries and Oceans Canada conducted the first baseline survey of offshore marine fishes, their habitats, and ecological relationships in the Canadian Beaufort Sea. Benthic trawling was conducted at 45 stations spanning 18-1001 m depths across shelf and slope habitats. Physical oceanographic variables (depth, salinity, temperature, oxygen), biological variables (benthic chlorophyll and integrated water-column chlorophyll) and sediment composition (grain size) were assessed as potential explanatory variables for fish community structure using a non-parametric statistical approach. Selected stations were re-sampled in 2013 and 2014 for a preliminary assessment of inter-annual variability in the fish community. Four distinct fish assemblages were delineated on the Canadian Beaufort Shelf and slope: 1) Nearshore-shelf: <50 m depth, 2) Offshore-shelf: >50 and ≤200 m depths, 3) Upper-slope: ≥200 and ≤500 m depths, and 4) Lower-slope: ≥500 m depths. Depth was the environmental variable that best explained fish community structure, and each species assemblage was spatially associated with distinct aspects of the vertical water mass profile. Significant differences in the fish community from east to west were not detected, and the species composition of the assemblages on the Canadian Beaufort Shelf have not changed substantially over the past decade. This community analysis provides a framework for testing

  17. Adaptation to reef habitats through selection on the coral animal and its associated microbiome.

    PubMed

    van Oppen, Madeleine J H; Bongaerts, Pim; Frade, Pedro; Peplow, Lesa M; Boyd, Sarah E; Nim, Hieu T; Bay, Line K

    2018-06-13

    Spatially adjacent habitats on coral reefs can represent highly distinct environments, often harbouring different coral communities. Yet, certain coral species thrive across divergent environments. It is unknown whether the forces of selection are sufficiently strong to overcome the counteracting effects of the typically high gene flow over short distances, and for local adaptation to occur. We screened the coral genome (using restriction-site-associated sequencing [RAD-seq]), and characterized both the dinoflagellate photosymbiont and tissue-associated prokaryote microbiomes (using metabarcoding) of a reef flat and slope population of the reef-building coral, Pocillopora damicornis, at two locations on Heron Island in the southern Great Barrier Reef. Reef flat and slope populations were separated by <100 m horizontally and ~5 m vertically and the two study locations were separated by ~1 km. For the coral host, genetic divergence between habitats was much greater than between locations, suggesting limited gene flow between the flat and slope populations. Consistent with environmental selection, outlier loci primarily belonged to the conserved, minimal cellular stress response, likely reflecting adaptation to the different temperature and irradiance regimes on the reef flat and slope. Similarly, the prokaryote community differed across both habitat and, to a lesser extent, location, whereas the dinoflagellate photosymbionts differed by habitat but not location. The observed intra-specific diversity associated with divergent habitats supports that environmental adaptation involves multiple members of the coral holobiont. Adaptive alleles or microbial associations present in coral populations from the environmentally-variable reef flat may provide a source of adaptive variation for assisted evolution approaches, through assisted gene flow, artificial cross-breeding or probiotic inoculations, with the aim to increase climate resilience in the slope populations. This

  18. Quantifying shark distribution patterns and species-habitat associations: implications of marine park zoning.

    PubMed

    Espinoza, Mario; Cappo, Mike; Heupel, Michelle R; Tobin, Andrew J; Simpfendorfer, Colin A

    2014-01-01

    Quantifying shark distribution patterns and species-specific habitat associations in response to geographic and environmental drivers is critical to assessing risk of exposure to fishing, habitat degradation, and the effects of climate change. The present study examined shark distribution patterns, species-habitat associations, and marine reserve use with baited remote underwater video stations (BRUVS) along the entire Great Barrier Reef Marine Park (GBRMP) over a ten year period. Overall, 21 species of sharks from five families and two orders were recorded. Grey reef Carcharhinus amblyrhynchos, silvertip C. albimarginatus, tiger Galeocerdo cuvier, and sliteye Loxodon macrorhinus sharks were the most abundant species (>64% of shark abundances). Multivariate regression trees showed that hard coral cover produced the primary split separating shark assemblages. Four indicator species had consistently higher abundances and contributed to explaining most of the differences in shark assemblages: C. amblyrhynchos, C. albimarginatus, G. cuvier, and whitetip reef Triaenodon obesus sharks. Relative distance along the GBRMP had the greatest influence on shark occurrence and species richness, which increased at both ends of the sampling range (southern and northern sites) relative to intermediate latitudes. Hard coral cover and distance across the shelf were also important predictors of shark distribution. The relative abundance of sharks was significantly higher in non-fished sites, highlighting the conservation value and benefits of the GBRMP zoning. However, our results also showed that hard coral cover had a large effect on the abundance of reef-associated shark species, indicating that coral reef health may be important for the success of marine protected areas. Therefore, understanding shark distribution patterns, species-habitat associations, and the drivers responsible for those patterns is essential for developing sound management and conservation approaches.

  19. Accuracy of gap analysis habitat models in predicting physical features for wildlife-habitat associations in the southwest U.S.

    USGS Publications Warehouse

    Boykin, K.G.; Thompson, B.C.; Propeck-Gray, S.

    2010-01-01

    Despite widespread and long-standing efforts to model wildlife-habitat associations using remotely sensed and other spatially explicit data, there are relatively few evaluations of the performance of variables included in predictive models relative to actual features on the landscape. As part of the National Gap Analysis Program, we specifically examined physical site features at randomly selected sample locations in the Southwestern U.S. to assess degree of concordance with predicted features used in modeling vertebrate habitat distribution. Our analysis considered hypotheses about relative accuracy with respect to 30 vertebrate species selected to represent the spectrum of habitat generalist to specialist and categorization of site by relative degree of conservation emphasis accorded to the site. Overall comparison of 19 variables observed at 382 sample sites indicated ???60% concordance for 12 variables. Directly measured or observed variables (slope, soil composition, rock outcrop) generally displayed high concordance, while variables that required judgments regarding descriptive categories (aspect, ecological system, landform) were less concordant. There were no differences detected in concordance among taxa groups, degree of specialization or generalization of selected taxa, or land conservation categorization of sample sites with respect to all sites. We found no support for the hypothesis that accuracy of habitat models is inversely related to degree of taxa specialization when model features for a habitat specialist could be more difficult to represent spatially. Likewise, we did not find support for the hypothesis that physical features will be predicted with higher accuracy on lands with greater dedication to biodiversity conservation than on other lands because of relative differences regarding available information. Accuracy generally was similar (>60%) to that observed for land cover mapping at the ecological system level. These patterns demonstrate

  20. Fish populations associated with habitat-modified piers and natural woody debris in Piedmont Carolina reservoirs

    USGS Publications Warehouse

    Barwick, R.D.; Kwak, T.J.; Noble, R.L.; Barwick, D.H.

    2004-01-01

    A primary concern associated with reservoir shoreline residential development is reduction of littoral habitat complexity and diversity. One potential approach to compensate for this is the deployment of artificial-habitat modules under existing piers, but the benefit of this practice has not been demonstrated. To evaluate the effect of pier habitat modifications on fish populations in two Piedmont Carolina reservoirs, we studied 77 piers located on forty-seven, 100-m transects that were modified using plastic "fish hab" modules augmented with brush (brushed habs), hab modules alone (habs), or left unaltered for reference purposes. We sampled fish from all piers and transects during April, July, and October 2001 using a boat-mounted electrofisher. With few exceptions, catch rates were higher at brushed-hab piers and piers with habs than at reference piers during all seasons. Similarly, during spring and summer, fish abundance was generally higher on transects containing natural woody debris, brushed habs, and habs than on reference-developed transects; however, during fall, there were exceptions. Therefore, fish abundance associated with shorelines in these reservoirs appears to be related to the structural complexity of available habitat rather than structure composition. One year after installation, 92% of pier owners responding to a mail survey expressed satisfaction with pier modifications. Supplementing piers with habitat structures is recommended to enhance littoral habitat complexity for fishes in residentially developed reservoirs.

  1. Quantifying Shark Distribution Patterns and Species-Habitat Associations: Implications of Marine Park Zoning

    PubMed Central

    Espinoza, Mario; Cappo, Mike; Heupel, Michelle R.; Tobin, Andrew J.; Simpfendorfer, Colin A.

    2014-01-01

    Quantifying shark distribution patterns and species-specific habitat associations in response to geographic and environmental drivers is critical to assessing risk of exposure to fishing, habitat degradation, and the effects of climate change. The present study examined shark distribution patterns, species-habitat associations, and marine reserve use with baited remote underwater video stations (BRUVS) along the entire Great Barrier Reef Marine Park (GBRMP) over a ten year period. Overall, 21 species of sharks from five families and two orders were recorded. Grey reef Carcharhinus amblyrhynchos, silvertip C. albimarginatus, tiger Galeocerdo cuvier, and sliteye Loxodon macrorhinus sharks were the most abundant species (>64% of shark abundances). Multivariate regression trees showed that hard coral cover produced the primary split separating shark assemblages. Four indicator species had consistently higher abundances and contributed to explaining most of the differences in shark assemblages: C. amblyrhynchos, C. albimarginatus, G. cuvier, and whitetip reef Triaenodon obesus sharks. Relative distance along the GBRMP had the greatest influence on shark occurrence and species richness, which increased at both ends of the sampling range (southern and northern sites) relative to intermediate latitudes. Hard coral cover and distance across the shelf were also important predictors of shark distribution. The relative abundance of sharks was significantly higher in non-fished sites, highlighting the conservation value and benefits of the GBRMP zoning. However, our results also showed that hard coral cover had a large effect on the abundance of reef-associated shark species, indicating that coral reef health may be important for the success of marine protected areas. Therefore, understanding shark distribution patterns, species-habitat associations, and the drivers responsible for those patterns is essential for developing sound management and conservation approaches. PMID

  2. Identifying selectively important amino acid positions associated with alternative habitat environments in fish mitochondrial genomes.

    PubMed

    Xia, Jun Hong; Li, Hong Lian; Zhang, Yong; Meng, Zi Ning; Lin, Hao Ran

    2018-05-01

    Fish species inhabitating seawater (SW) or freshwater (FW) habitats have to develop genetic adaptations to alternative environment factors, especially salinity. Functional consequences of the protein variations associated with habitat environments in fish mitochondrial genomes have not yet received much attention. We analyzed 829 complete fish mitochondrial genomes and compared the amino acid differences of 13 mitochondrial protein families between FW and SW fish groups. We identified 47 specificity determining sites (SDS) that associated with FW or SW environments from 12 mitochondrial protein families. Thirty-two (68%) of the SDS sites are hydrophobic, 13 (28%) are neutral, and the remaining sites are acidic or basic. Seven of those SDS from ND1, ND2 and ND5 were scored as probably damaging to the protein structures. Furthermore, phylogenetic tree based Bayes Empirical Bayes analysis also detected 63 positive sites associated with alternative habitat environments across ten mtDNA proteins. These signatures could be important for studying mitochondrial genetic variation relevant to fish physiology and ecology.

  3. Evaluation of habitat quality for selected wildlife species associated with back channels.

    USGS Publications Warehouse

    Anderson, James T.; Zadnik, Andrew K.; Wood, Petra Bohall; Bledsoe, Kerry

    2013-01-01

    The islands and associated back channels on the Ohio River, USA, are believed to provide critical habitat features for several wildlife species. However, few studies have quantitatively evaluated habitat quality in these areas. Our main objective was to evaluate the habitat quality of back and main channel areas for several species using habitat suitability index (HSI) models. To test the effectiveness of these models, we attempted to relate HSI scores and the variables measured for each model with measures of relative abundance for the model species. The mean belted kingfisher (Ceryle alcyon) HSI was greater on the main than back channel. However, the model failed to predict kingfisher abundance. The mean reproduction component of the great blue heron (Ardea herodias) HSI, total common muskrat (Ondatra zibethicus) HSI, winter cover component of the snapping turtle (Chelydra serpentina) HSI, and brood-rearing component of the wood duck (Aix sponsa) HSI were all greater on the back than main channel, and were positively related with the relative abundance of each species. We found that island back channels provide characteristics not found elsewhere on the Ohio River and warrant conservation as important riparian wildlife habitat. The effectiveness of using HSI models to predict species abundance on the river was mixed. Modifications to several of the models are needed to improve their use on the Ohio River and, likely, other large rivers.

  4. Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities.

    PubMed

    Fabricius, K E; De'ath, G; Noonan, S; Uthicke, S

    2014-01-22

    The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO2) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO2 (425-1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO2 tolerances derived from laboratory experiments. High CO2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs.

  5. Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities

    PubMed Central

    Fabricius, K. E.; De'ath, G.; Noonan, S.; Uthicke, S.

    2014-01-01

    The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO2) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO2 (425–1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO2 tolerances derived from laboratory experiments. High CO2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs. PMID:24307670

  6. Associations of wintering birds with habitat in semidesert and plains grasslands in Arizona

    USGS Publications Warehouse

    Ruth, Janet M.; Stanley, Thomas R.; Gordon, Caleb E.

    2014-01-01

    We studied associations with winter habitat for seven species of birds, one species-group (eastern and western meadowlarks combined), and total sparrows at seven sites in the semidesert and plains grasslands of southeastern Arizona from 1999–2001, sampling with mist-nets and survey-transects. We measured structure and composition of vegetation, assessing vegetative differences among sites, and modeled associations between indices of avian abundance and six vegetative variables using generalized linear models. For all vegetative variables, there were significant differences among sites. Numbers of northern harriers (Circus cyaneus) were positively associated with total number of sparrows. Indices of abundance for individual species of birds were statistically correlated with various measures of structure and composition of vegetation. In particular, grasshopper (Ammodramus savannarum) and vesper (Pooecetes gramineus) sparrows were negatively associated with amount of bare ground; horned larks (Eremophila alpestris) were negatively associated with vertical grass density; Baird's sparrows (A. bairdii) were negatively associated with shrub density; meadowlarks (Sturnella magna and S. neglecta combined) were positively associated with native grass. Our results suggest that these species would benefit from management of habitat that affects the vegetative characteristics associated with their abundance.

  7. Wildlife habitat associations in eastern hemlock - birds, smaller mammals, and forest carnivores

    Treesearch

    Mariko Yamasaki; Richard M. DeGraaf; John W. Lanier

    2000-01-01

    Ninety-six bird and forty-seven mammal species are associated with the hemlock type in the northeastern United States. Of these species eight bird and ten mammal species are strongly associated with the hemlock type though none of these species are limited to it. Hemlock species richness appears to be lower than in other conifer or hardwood types. Avian habitat...

  8. Whole-community mutualism: associated invertebrates facilitate a dominant habitat-forming seaweed.

    PubMed

    Bracken, Matthew E S; Gonzalez-Dorantes, Cirse A; Stachowicz, John J

    2007-09-01

    Many habitat-forming, or foundation, species harbor diverse assemblages of associated taxa that benefit from the refuges from predators or harsh physical conditions that foundation species provide. Growing numbers of studies show how specific taxa associated with foundation species can benefit their hosts, but the aggregate effects of the entire community of associated species remain poorly understood. Here, we evaluate the role that a diverse assemblage of invertebrates plays in mediating the dominance of a foundation species, the green filamentous seaweed Cladophora columbiana Collins, in rocky intertidal habitats. Cladophora is a fast-growing seaweed with a high nitrogen demand, and we suggest that it persists in nutrient-limited high-intertidal pools because of local-scale nitrogen excretion by the invertebrate taxa living within its filaments. Removal of associated invertebrates resulted in a fourfold increase in the rate of water-column nitrogen depletion by Cladophora, and ammonium concentrations inside Cladophora turfs with invertebrates present were seven times higher than in the adjacent tide-pool water. The ammonium excreted by invertebrate meiofauna far surpassed the nitrogen used by Cladophora, suggesting that all of Cladophora's nitrogen requirements could be met by the invertebrates associated with it. This study links host performance to the total aggregate biomass of mutualists rather than the particular traits of any one species, suggesting the potential for important feedbacks between individual hosts and the communities of associated species that they support.

  9. The association of Antarctic krill Euphausia superba with the under-ice habitat.

    PubMed

    Flores, Hauke; van Franeker, Jan Andries; Siegel, Volker; Haraldsson, Matilda; Strass, Volker; Meesters, Erik Hubert; Bathmann, Ulrich; Wolff, Willem Jan

    2012-01-01

    The association of Antarctic krill Euphausia superba with the under-ice habitat was investigated in the Lazarev Sea (Southern Ocean) during austral summer, autumn and winter. Data were obtained using novel Surface and Under Ice Trawls (SUIT), which sampled the 0-2 m surface layer both under sea ice and in open water. Average surface layer densities ranged between 0.8 individuals m(-2) in summer and autumn, and 2.7 individuals m(-2) in winter. In summer, under-ice densities of Antarctic krill were significantly higher than in open waters. In autumn, the opposite pattern was observed. Under winter sea ice, densities were often low, but repeatedly far exceeded summer and autumn maxima. Statistical models showed that during summer high densities of Antarctic krill in the 0-2 m layer were associated with high ice coverage and shallow mixed layer depths, among other factors. In autumn and winter, density was related to hydrographical parameters. Average under-ice densities from the 0-2 m layer were higher than corresponding values from the 0-200 m layer collected with Rectangular Midwater Trawls (RMT) in summer. In winter, under-ice densities far surpassed maximum 0-200 m densities on several occasions. This indicates that the importance of the ice-water interface layer may be under-estimated by the pelagic nets and sonars commonly used to estimate the population size of Antarctic krill for management purposes, due to their limited ability to sample this habitat. Our results provide evidence for an almost year-round association of Antarctic krill with the under-ice habitat, hundreds of kilometres into the ice-covered area of the Lazarev Sea. Local concentrations of postlarval Antarctic krill under winter sea ice suggest that sea ice biota are important for their winter survival. These findings emphasise the susceptibility of an ecological key species to changing sea ice habitats, suggesting potential ramifications on Antarctic ecosystems induced by climate change.

  10. The Association of Antarctic Krill Euphausia superba with the Under-Ice Habitat

    PubMed Central

    Flores, Hauke; van Franeker, Jan Andries; Siegel, Volker; Haraldsson, Matilda; Strass, Volker; Meesters, Erik Hubert; Bathmann, Ulrich; Wolff, Willem Jan

    2012-01-01

    The association of Antarctic krill Euphausia superba with the under-ice habitat was investigated in the Lazarev Sea (Southern Ocean) during austral summer, autumn and winter. Data were obtained using novel Surface and Under Ice Trawls (SUIT), which sampled the 0–2 m surface layer both under sea ice and in open water. Average surface layer densities ranged between 0.8 individuals m−2 in summer and autumn, and 2.7 individuals m−2 in winter. In summer, under-ice densities of Antarctic krill were significantly higher than in open waters. In autumn, the opposite pattern was observed. Under winter sea ice, densities were often low, but repeatedly far exceeded summer and autumn maxima. Statistical models showed that during summer high densities of Antarctic krill in the 0–2 m layer were associated with high ice coverage and shallow mixed layer depths, among other factors. In autumn and winter, density was related to hydrographical parameters. Average under-ice densities from the 0–2 m layer were higher than corresponding values from the 0–200 m layer collected with Rectangular Midwater Trawls (RMT) in summer. In winter, under-ice densities far surpassed maximum 0–200 m densities on several occasions. This indicates that the importance of the ice-water interface layer may be under-estimated by the pelagic nets and sonars commonly used to estimate the population size of Antarctic krill for management purposes, due to their limited ability to sample this habitat. Our results provide evidence for an almost year-round association of Antarctic krill with the under-ice habitat, hundreds of kilometres into the ice-covered area of the Lazarev Sea. Local concentrations of postlarval Antarctic krill under winter sea ice suggest that sea ice biota are important for their winter survival. These findings emphasise the susceptibility of an ecological key species to changing sea ice habitats, suggesting potential ramifications on Antarctic ecosystems induced by climate

  11. Echinoid associations with coral habitats differ with taxon in the deep sea and the influence of other echinoids, depth, and fishing history on their distribution

    NASA Astrophysics Data System (ADS)

    Stevenson, Angela; Davies, Jaime S.; Williams, Alan; Althaus, Franziska; Rowden, Ashley A.; Bowden, David A.; Clark, Malcolm R.; Mitchell, Fraser J. G.

    2018-03-01

    Patterns of habitat use by animals and knowledge of the environmental factors affecting these spatial patterns are important for understanding the structure and dynamics of ecological communities. Both aspects are poorly known for deep-sea habitats. The present study investigates echinoid distributions within cold water coral (CWC) habitats on continental margins off France, Australia, and New Zealand. It further examines the influence of habitat-related variables that might help explain the observed distribution of echinoid taxa. Six echinoid taxa were examined from video and photographic transects to reveal taxon-specific distribution patterns and habitat-related influences. The Echinoidea were found in all habitats studied, but tended to aggregate in architecturally complex habitats associated with living cold-water corals. However, a taxon-specific investigation found that such associations were largely an artefact of the dominant taxa observed in a specific region. Despite the food and shelter resources offered to echinoids by matrix-forming coral habitats, not all taxa were associated with these habitats, and some had a random association with the habitats examined, while others displayed non-random associations. Echinoid distribution was correlated with several variables; the presence of other echinoids, depth, and fishing history were the most influential factors. This study indicates that image data can be a useful tool to detect trends in echinoid habitat associations. It also suggests that refinement of the methods, in particular with studies conducted at a more precise taxon and habitat scale, would facilitate better quantitative analyses of habitat associations and paint a more realistic picture of a population's ecology. Most deep-sea ecological studies to date have been conducted at a relatively coarse taxonomic and habitat resolution, and lack sufficient resolution to provide useful information for the conservation of vulnerable deep-sea habitats.

  12. Winter habitat associations of eastern spotted skunks in Virginia

    USGS Publications Warehouse

    Thorne, Emily D.; Waggy, Charles; Jachowski, David S.; Kelly, Marcella J.; Ford, W. Mark

    2017-01-01

    Eastern spotted skunk (Spilogale putorius) populations have declined throughout much of their range in the eastern United States over recent decades. Declines have been attributed to habitat loss or change, increased competition with sympatric mesocarnivore species, or disease. To better understand the extant distribution of spotted skunks in the Appalachian Mountains of western Virginia, USA, we used a detection-non-detection sampling approach using baited camera traps to evaluate the influence of landscape-level environmental covariates on spotted skunk detection probability and site occupancy. We conducted camera trap surveys at 91 sites from January to May in 2014 and 2015. Spotted skunk occupancy was associated with young-aged forest stands at lower elevations and more mature forest stands at higher elevations. Both land cover types in this region can be characterized as having complex forest structure, providing cover that varies with stand age, species composition, elevation, and management regime. Our results provide insight into factors that influence spotted skunk spatial distribution and habitat selection, information that can be used to generate conservation assessments and inform management decisions.

  13. Habitat associated with Barred Owl (Strix varia) locations in southeastern Manitoba: a review of a habitat model

    Treesearch

    James R. Duncan; Amy E. Kearns

    1997-01-01

    A Habitat Suitability Index (HSI) model was developed for the Barred Owl (Strix varia) in southeastern Manitoba. An initial validation of the model was performed within three sizes of circular plots (314, 1,256, and 2,827 ha) centered on 28 Barred Owl locations. The model was able to predict suitable habitat at the 314 ha scale. Forest habitat...

  14. Associations among habitat characteristics and meningeal worm prevalence in eastern South Dakota, USA

    USGS Publications Warehouse

    Jacques, Christopher N.; Jenks, Jonathan A.; Klaver, Robert W.; Dubay, Shelli A.

    2017-01-01

    Few studies have evaluated how wetland and forest characteristics influence the prevalence of meningeal worm (Parelaphostrongylus tenuis) infection of deer throughout the grassland biome of central North America. We used previously collected, county-level prevalence data to evaluate associations between habitat characteristics and probability of meningeal worm infection in white-tailed deer (Odocoileus virginianus) across eastern South Dakota, US. The highest-ranked binomial regression model for detecting probability of meningeal worm infection was spring temperature + summer precipitation + percent wetland; weight of evidence (wi=0.71) favored this model over alternative models, though predictive capability was low (Receiver operating characteristic=0.62). Probability of meningeal worm infection increased by 1.3- and 1.6-fold for each 1-cm and 1-C increase in summer precipitation and spring temperature, respectively. Similarly, probability of infection increased 1.2-fold for each 1% increase in wetland habitat. Our findings highlight the importance of wetland habitat in predicting meningeal worm infection across eastern South Dakota. Future research is warranted to evaluate the relationships between climatic conditions (e.g., drought, wet cycles) and deer habitat selection in maintaining P. tenuis along the western boundary of the parasite.

  15. Demographic consequences of terrestrial habitat loss for pool-breeding amphibians: predicting extinction risks associated with inadequate size of buffer zones.

    PubMed

    Harper, Elizabeth B; Rittenhouse, Tracy A G; Semlitsch, Raymond D

    2008-10-01

    Much of the biodiversity associated with isolated wetlands requires aquatic and terrestrial habitat to maintain viable populations. Current federal wetland regulations in the United States do not protect isolated wetlands or extend protection to surrounding terrestrial habitat. Consequently, some land managers, city planners, and policy makers at the state and local levels are making an effort to protect these wetland and neighboring upland habitats. Balancing human land-use and habitat conservation is challenging, and well-informed land-use policy is hindered by a lack of knowledge of the specific risks of varying amounts of habitat loss. Using projections of wood frog (Rana sylvatica) and spotted salamander (Ambystoma maculatum) populations, we related the amount of high-quality terrestrial habitat surrounding isolated wetlands to the decline and risk of extinction of local amphibian populations. These simulations showed that current state-level wetland regulations protecting 30 m or less of surrounding terrestrial habitat are inadequate to support viable populations of pool-breeding amphibians. We also found that species with different life-history strategies responded differently to the loss and degradation of terrestrial habitat. The wood frog, with a short life span and high fecundity, was most sensitive to habitat loss and isolation, whereas the longer-lived spotted salamander with lower fecundity was most sensitive to habitat degradation that lowered adult survival rates. Our model results demonstrate that a high probability of local amphibian population persistence requires sufficient terrestrial habitat, the maintenance of habitat quality, and connectivity among local populations. Our results emphasize the essential role of adequate terrestrial habitat to the maintenance of wetland biodiversity and ecosystem function and offer a means of quantifying the risks associated with terrestrial habitat loss and degradation.

  16. Diversity and habitat association of small mammals in Aridtsy forest, Awi Zone, Ethiopia.

    PubMed

    Bantihun, Getachew; Bekele, Afework

    2015-03-18

    Here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from August 2011 to February 2012 incorporating both wet and dry seasons in Aridtsy forest, Awi Zone, Ethiopia. Using Sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals (live traps) and 89 rodents of six species (snap traps) were trapped in 2352 and 1200 trap nights, respectively. The trapped small mammals included seven rodents and one insectivore: Lophuromys flavopuntatus (30.6%), Arvicanthis dembeensis (25.8%), Stenocephalemys albipes (20%), Mastomys natalensis (11.6%), Pelomys harringtoni (6.4%), Acomys cahirinus (4.3%), Lemniscomys zebra (0.2%) and the greater red musk shrew (Crocidura flavescens, 1.1%). Analysis showed statistically significant variations in the abundance and habitat preferences of small mammals between habitats during wet and dry seasons.

  17. Fish Assemblages Associated with Natural and Anthropogenically-Modified Habitats in a Marine Embayment: Comparison of Baited Videos and Opera-House Traps

    PubMed Central

    Wakefield, Corey B.; Lewis, Paul D.; Coutts, Teresa B.; Fairclough, David V.; Langlois, Timothy J.

    2013-01-01

    Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment. PMID:23555847

  18. Fish assemblages associated with natural and anthropogenically-modified habitats in a marine embayment: comparison of baited videos and opera-house traps.

    PubMed

    Wakefield, Corey B; Lewis, Paul D; Coutts, Teresa B; Fairclough, David V; Langlois, Timothy J

    2013-01-01

    Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment.

  19. Ichthyoplankton assemblages of coastal west-central Lake Erie and associated habitat characteristics

    USGS Publications Warehouse

    McKenna, J.E.; Hunter, R. Douglas; Fabrizio, M.C.; Savino, J.F.; Todd, T.N.; Bur, M.

    2008-01-01

    Early life stage survival often determines fish cohort strength and that survival is affected by habitat conditions. The structure and dynamics of ichthyoplankton assemblages can tell us much about biodiversity and fish population dynamics, but are poorly understood in nearshore areas of the Great Lakes, where most spawning and nursery habitats exist. Ichthyoplankton samples were collected with a neuston net in waters 2-13 m deep weekly or biweekly from mid-April through August, during 3 years (2000-2002) as part of a study of fish assemblages in west-central Lake Erie. A suite of abiotic variables was simultaneously measured to characterize habitat. Cluster and ordination analyses revealed several distinct ichthyoplankton assemblages that changed seasonally. A lake whitefish (Coregonus clupeaformis) dominated assemblage appeared first in April. In May, assemblages were dominated by several percid species. Summer assemblages were overwhelmingly dominated by emerald shiner (Notropis atherinoides), with large gizzard shad (Dorosoma cepedianum) and alewife (Alosa pseudoharengus) components. This seasonal trend in species assemblages was also associated with increasing temperature and water clarity. Water depth and drift processes may also play a role in structuring these assemblages. The most common and widely distributed assemblages were not associated with substratum type, which we characterized as either hard or soft. The timing of hatch and larval growth separated the major groups in time and may have adaptive significance for the members of each major assemblage. The quality and locations (with reference to lake circulation) of spawning and nursery grounds may determine larval success and affect year class strength.

  20. Polymorphic mountain whitefish (Prosopium williamsoni) in a coastal riverscape: size class assemblages, distribution, and habitat associations

    USGS Publications Warehouse

    Starr, James C.; Torgersen, Christian E.

    2015-01-01

    We compared the assemblage structure, spatial distributions, and habitat associations of mountain whitefish (Prosopium williamsoni) morphotypes and size classes. We hypothesised that morphotypes would have different spatial distributions and would be associated with different habitat features based on feeding behaviour and diet. Spatially continuous sampling was conducted over a broad extent (29 km) in the Calawah River, WA (USA). Whitefish were enumerated via snorkelling in three size classes: small (10–29 cm), medium (30–49 cm), and large (≥50 cm). We identified morphotypes based on head and snout morphology: a pinocchio form that had an elongated snout and a normal form with a blunted snout. Large size classes of both morphotypes were distributed downstream of small and medium size classes, and normal whitefish were distributed downstream of pinocchio whitefish. Ordination of whitefish assemblages with nonmetric multidimensional scaling revealed that normal whitefish size classes were associated with higher gradient and depth, whereas pinocchio whitefish size classes were positively associated with pool area, distance upstream, and depth. Reach-scale generalised additive models indicated that normal whitefish relative density was associated with larger substrate size in downstream reaches (R2 = 0.64), and pinocchio whitefish were associated with greater stream depth in the reaches farther upstream (R2 = 0.87). These results suggest broad-scale spatial segregation (1–10 km), particularly between larger and more phenotypically extreme individuals. These results provide the first perspective on spatial distributions and habitat relationships of polymorphic mountain whitefish.

  1. Clear Creek Watershed Flood Risk Management Habitat Assessments Using Habitat Evaluation Procedures (HEP): Analyses, Results and Documentation

    DTIC Science & Technology

    2013-07-01

    endangered species and their associated habitats as an important goal of ecosystem restoration and management. There is no doubt the determination of...accounting process developed to appraise habitat suitability for fish and wildlife species in response to potential change (USFWS 1980a-c). HEP is an... habitat to a species is likely to exhibit strong thresholds below which the habitat is usually unsuitable and above which further changes in habitat

  2. Seasonal habitat associations of the wolverine in central Idaho

    Treesearch

    Jeffrey P. Copeland; James M. Peek; Craig R. Groves; Wayne E. Melquist; Kevin S. Mckelvey; Gregory W. McDaniel; Clinton D. Long; Charles E. Harris

    2007-01-01

    Although understanding habitat relationships remains fundamental to guiding wildlife management, these basic prerequisites remain vague and largely unstudied for the wolverine. Currently, a study of wolverine ecology conducted in Montana, USA, in the 1970s is the sole source of information on habitat requirements of wolverines in the conterminous United States. The...

  3. Distribution and habitat associations of juvenile Common Snook in the lower Rio Grande, Texas

    USGS Publications Warehouse

    Huber, Caleb G.; Grabowski, Timothy B.; Patino, Reynaldo; Pope, Kevin L.

    2014-01-01

    Common Snook Centropomus undecimalis were once abundant off the Texas coast, but these populations are now characterized by low abundance and erratic recruitment. Most research concerning Common Snook in North America has been conducted in Florida and very little is known about the specific biology and habitat needs of Common Snook in Texas. The primary objective of this study was to describe the habitat use patterns of juvenile Common Snook and their role in the fish assemblage in the lower portion of the Rio Grande, Texas. Secondarily, we documented the relationship between age and juvenile reproductive development. Fish were collected during January–March 2006 from the lower 51.5 km of the Rio Grande using a bottom trawl and boat-mounted electrofisher. Measurements of water quality and other habitat traits were recorded at each sampling site. We captured 225 Common Snook exclusively in freshwater habitats above river kilometer 12.9. The distribution of juvenile Common Snook was not random, but influenced primarily by turbidity and dissolved oxygen. Sex differentiation and gonadal development based on histological examination of gonads established that age-1 and age-2 Common Snook were juvenile, prepubertal males. There was no difference between the age groups in their overall distribution in the river. However, age-2 Common Snook were associated with deeper areas with faster currents, higher conductivity, and steeper banks. Overall, Common Snook in the lower Rio Grande show substantial differences in habitat use than their counterparts in other parts of the range of the species, but it is unclear whether this is due to differences in habitat availability, behavioral plasticity, or some combination thereof.

  4. Forest habitat associations of the golden-mantled ground squirrel: Implications for fuels management

    Treesearch

    Katharine R. Shick; Dean E. Pearson; Leonard F. Ruggiero

    2006-01-01

    Golden-mantled ground squirrels are commonly associated with high-elevation habitats near or above upper timberline. This species also occurs in fire-adapted, low-elevation forests that are targeted for forest health restoration (FHR) treatments intended to remove encroaching understory trees and thin overstory trees. Hence, the golden-mantled ground squirrel...

  5. Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus)

    PubMed Central

    Seebacher, Frank; Webster, Mike M.; James, Rob S.; Tallis, Jason; Ward, Ashley J. W.

    2016-01-01

    Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits. PMID:27429785

  6. Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus).

    PubMed

    Seebacher, Frank; Webster, Mike M; James, Rob S; Tallis, Jason; Ward, Ashley J W

    2016-06-01

    Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits.

  7. Evidence for a plant-associated natural habitat for Cronobacter spp.

    PubMed

    Schmid, Michael; Iversen, Carol; Gontia, Iti; Stephan, Roger; Hofmann, Andreas; Hartmann, Anton; Jha, Bhavanath; Eberl, Leo; Riedel, Kathrin; Lehner, Angelika

    2009-10-01

    Cronobacter (Enterobacter sakazakii) species are responsible for rare cases of necrotising enterocolitis and bacteraemia in infants, as well as cases of meningitis with high case fatality rates in neonates and immunocompromised infants. Some physiological features, such as the production of a yellow pigment, the formation of a gum-like extracellular polysaccharide and the ability to persist in a desiccated state, suggest an environmental niche for these organisms. To date, the natural habitat of Cronobacter spp. remains unknown. In this report, the isolation and characterisation of two Cronobacter sakazakii strains from plant roots is described. Also, the root colonisation behaviour of Cronobacter strains originating from clinical and plant sources is assessed. The nine strains investigated showed features often found in plant-associated and rhizosphere microorganisms, including solubilisation of mineral phosphate and production of indole acetic acid. Siderophore production was observed for all except one strain. In addition, the capability to endophytically colonise tomato and maize roots was demonstrated for several strains, either by fluorescence in situ hybridisation, using fluorescently labelled oligonucleotide probes, or by using strains tagged with green fluorescent protein and confocal laser scanning microscopy. The results provide evidence that plants may be the natural habitat of Cronobacter spp.

  8. A Filifactor alocis-centered co-occurrence group associates with periodontitis across different oral habitats

    PubMed Central

    Chen, Hui; Liu, Ying; Zhang, Menghui; Wang, Guoyang; Qi, Zhengnan; Bridgewater, Laura; Zhao, Liping; Tang, Zisheng; Pang, Xiaoyan

    2015-01-01

    Periodontitis is a highly prevalent polymicrobial disease worldwide, yet the synergistic pattern of the multiple oral pathogens involved is still poorly characterized. Here, saliva, supragingival and subgingival plaque samples from periodontitis patients and periodontally healthy volunteers were collected and profiled with 16S rRNA gene pyrosequencing. Different oral habitats harbored significantly different microbiota, and segregation of microbiota composition between periodontitis and health was observed as well. Two-step redundancy analysis identified twenty-one OTUs, including Porphyromonas gingivalis, Tannerella forsythia and Filifactor alocis, as potential pathogens that were significantly associated with periodontitis and with two periodontitis diagnostic parameters (pocket depth and attachment loss) in both saliva and supragingival plaque habitats. Interestingly, pairwise correlation analysis among the 21 OTUs revealed that Filifactor alocis was positively correlated with seven other putative pathogens (R > 0.6, P < 0.05), forming a co-occurrence group that was remarkably enriched in all three habitats of periodontitis patients. This bacterial cluster showed a higher diagnostic value for periodontitis than did any individual potential pathogens, especially in saliva. Thus, our study identified a potential synergistic ecological pattern involving eight co-infecting pathogens across various oral habitats, providing a new framework for understanding the etiology of periodontitis and developing new diagnoses and therapies. PMID:25761675

  9. Resolution of habitat-associated ecogenomic signatures in bacteriophage genomes and application to microbial source tracking.

    PubMed

    Ogilvie, Lesley A; Nzakizwanayo, Jonathan; Guppy, Fergus M; Dedi, Cinzia; Diston, David; Taylor, Huw; Ebdon, James; Jones, Brian V

    2018-04-01

    Just as the expansion in genome sequencing has revealed and permitted the exploitation of phylogenetic signals embedded in bacterial genomes, the application of metagenomics has begun to provide similar insights at the ecosystem level for microbial communities. However, little is known regarding this aspect of bacteriophage associated with microbial ecosystems, and if phage encode discernible habitat-associated signals diagnostic of underlying microbiomes. Here we demonstrate that individual phage can encode clear habitat-related 'ecogenomic signatures', based on relative representation of phage-encoded gene homologues in metagenomic data sets. Furthermore, we show the ecogenomic signature encoded by the gut-associated ɸB124-14 can be used to segregate metagenomes according to environmental origin, and distinguish 'contaminated' environmental metagenomes (subject to simulated in silico human faecal pollution) from uncontaminated data sets. This indicates phage-encoded ecological signals likely possess sufficient discriminatory power for use in biotechnological applications, such as development of microbial source tracking tools for monitoring water quality.

  10. DISTRIBUTION OF AQUATIC OFF-CHANNEL HABITATS AND ASSOCIATED RIPARIAN VEGETATION, WILLAMETTE RIVER, OREGON, USA

    EPA Science Inventory

    The extent of aquatic off-channel habitats such as secondary and side channels, sloughs, and alcoves, have been reduced more than 50% since the 1850s along the upper main stem of the Willamette River, Oregon, USA. Concurrently, the hydrogeomorphic potential, and associated flood...

  11. Leaf trait variations associated with habitat affinity of tropical karst tree species.

    PubMed

    Geekiyanage, Nalaka; Goodale, Uromi Manage; Cao, Kunfang; Kitajima, Kaoru

    2018-01-01

    Karst hills, that is, jagged topography created by dissolution of limestone and other soluble rocks, are distributed extensively in tropical forest regions, including southern parts of China. They are characterized by a sharp mosaic of water and nutrient availability, from exposed hilltops with poor soil development to valleys with occasional flooding, to which trees show species-specific distributions. Here we report the relationship of leaf functional traits to habitat preference of tropical karst trees. We described leaf traits of 19 tropical tree species in a seasonal karst rainforest in Guangxi Province, China, 12 species in situ and 13 ex situ in a non-karst arboretum, which served as a common garden, with six species sampled in both. We examined how the measured leaf traits differed in relation to species' habitat affinity and evaluated trait consistency between natural habitats vs . the arboretum. Leaf mass per area (LMA) and optical traits (light absorption and reflectance characteristics between 400 and 1,050 nm) showed significant associations with each other and habitats, with hilltop species showing high values of LMA and low values of photochemical reflectance index (PRI). For the six species sampled in both the karst forest and the arboretum, LMA, leaf dry matter content, stomatal density, and vein length per area showed inconsistent within-species variations, whereas some traits (stomatal pore index and lamina thickness) were similar between the two sites. In conclusion, trees specialized in exposed karst hilltops with little soils are characterized by thick leaves with high tissue density indicative of conservative resources use, and this trait syndrome could potentially be sensed remotely with PRI.

  12. Distribution and habitat association of benthic fish on the Condor seamount (NE Atlantic, Azores) from in situ observations

    NASA Astrophysics Data System (ADS)

    Porteiro, Filipe M.; Gomes-Pereira, José N.; Pham, Christopher K.; Tempera, Fernando; Santos, Ricardo S.

    2013-12-01

    Distribution of fish assemblages and habitat associations of demersal fishes on the Condor seamount were investigated by analyzing in situ video imagery acquired by the Remotely-Operated Vehicles ROV SP300 and Luso 6000. A total of 51 fish taxa from 32 families were inventoried. Zooplanktivores (10 species) were the most abundant group followed by carnivores (23 species) and benthivores (18 species). Non-metric multidimensional scaling (MDS) analyses were performed on dive segments to visualize the spatial relationships between species and habitat type, substrate type or depth, with depth being the most significant parameter influencing fish distribution. Four major fish groups were identified from their vertical distribution alone: summit species (generally to <300 m depth); broad ranging species (ca. from 200 to 800 m); intermediate ranging slope species (ca. from 400 m to 800-850 m); and deeper species (800-850-1100 m). The fish fauna observed at the summit is more abundant (15.2 fish/100 m2) and habitat-specialized than the fish observed along the seamount slope. Down the seamount slope, the summit fish assemblage is gradually replaced as depth increases, with an overall reduction in abundance. On the summit, three species (Callanthias ruber, Anthias anthias and Lappanella fasciata) had higher affinity to coral habitats compared to non-coral habitats. A coherent specialized fish assemblage associated to coral habitats could not be identified, because most species were observed also in non-coral areas. On the seamount's slope (300-1100 m), no relationship between fish and coral habitats could be identified, although these might occur at larger scales. This study shows that in situ video imagery complements traditional fishing surveys, by providing information on unknown or rarely seen species, being fundamental for the development of more comprehensive ecosystem-based management towards a sustainable use of the marine environment.

  13. Habitat associations of age-0 cutthroat trout in a spring stream improved for adult salmonids

    USGS Publications Warehouse

    Hubert, W.A.; Joyce, M.P.

    2005-01-01

    Native cutthroat trout (Oncorhynchus clarki) in the Snake River watershed use streams formed by large springs for spawning and nursery habitat. Several spring streams have been modified to enhance abundance of adult salmonids, but the habitat associations of age-0 cutthroat trout in these systems are undescribed. We assessed the frequency of collection of age-0 cutthroat trout in riffles, riffle margins, pool margins, and backwaters from late June to the middle of August 2000 in a spring stream with such modifications. The proportion of sites in which age-0 cutthroat trout were collected increased up to the middle of July and then decreased. We found substantially lower frequencies of collection of age-0 cutthroat trout in riffles compared to the three stream-margin habitat types. Age-0 cutthroat trout appeared to select shallow, low-velocity, stream-margin habitat with cover that provided protection from piscivorous adult salmonids and avian predators. Our observations suggest that modification of spring streams for production of cutthroat trout should include efforts to manage stream margins so they provide cover in the form of aquatic macrophytes or overhanging vegetation for age-0 fish.

  14. Detours in long-distance migration across the Qinghai-Tibetan Plateau: individual consistency and habitat associations.

    PubMed

    Liu, Dongping; Zhang, Guogang; Jiang, Hongxing; Lu, Jun

    2018-01-01

    Migratory birds often follow detours when confronted with ecological barriers, and understanding the extent and the underlying drivers of such detours can provide important insights into the associated cost to the annual energy budget and the migration strategies. The Qinghai-Tibetan Plateau is the most daunting geographical barrier for migratory birds because the partial pressure of oxygen is dramatically reduced and flight costs greatly increase. We analyzed the repeated migration detours and habitat associations of four Pallas's Gulls Larus ichthyaetus across the Qinghai-Tibetan Plateau over 22 migration seasons. Gulls exhibited notable detours, with the maximum distance being more than double that of the expected shortest route, that extended rather than reduced the passage across the plateau. The extent of longitudinal detours significantly increased with latitude, and detours were longer in autumn than in spring. Compared with the expected shortest routes, proximity to water bodies increased along autumn migration routes, but detour-habitat associations were weak along spring migration routes. Thus, habitat availability was likely one, but not the only, factor shaping the extent of detours, and migration routes were determined by different mechanisms between seasons. Significant between-individual variation but high individual consistency in migration timing and routes were revealed in both seasons, indicating a stronger influence of endogenous schedules than local environmental conditions. Gulls may benefit from repeated use of familiar routes and stopover sites, which may be particularly significant in the challenging environment of the Qinghai-Tibetan Plateau.

  15. Landscape genetics indicate recently increased habitat fragmentation in African forest-associated chafers.

    PubMed

    Eberle, Jonas; Rödder, Dennis; Beckett, Marc; Ahrens, Dirk

    2017-05-01

    Today, indigenous forests cover less than 0.6% of South Africa's land surface and are highly fragmented. Most forest relicts are very small and typically occur in fire-protected gorges along the eastern Great Escarpment. Yet, they hold a unique and valuable fauna with high endemism and ancient phylogenetic lineages, fostered by long-term climatic stability and complex microclimates. Despite numerous studies on southern African vegetation cover, the current state of knowledge about the natural extension of indigenous forests is rather fragmentary. We use an integrated approach of population-level phylogeography and climatic niche modeling of forest-associated chafer species to assess connectivity and extent of forest habitats since the last glacial maximum. Current and past species distribution models ascertained potential fluctuations of forest distribution and supported a much wider potential current extension of forests based on climatic data. Considerable genetic admixture of mitochondrial and nuclear DNA among many populations and an increase in mean population mutation rate in Extended Bayesian Skyline Plots of all species indicated more extended or better connected forests in the recent past (<5 kya). Genetic isolation of certain populations, as revealed by population differentiation statistics (GST'), as well as landscape connectivity statistics and habitat succession scenarios suggests considerable loss of habitat connectivity. As major anthropogenic influence is likely, conservational actions need to be considered. © 2017 John Wiley & Sons Ltd.

  16. Habitat associations of vertebrate prey within the controlled area study zone

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

    Marr, N.V.; Brandt, C.A.; Fitzner, R.E.

    1988-03-01

    Twelve study locations were established in nine habitat types in the vicinity of the proposed reference repository location. Eight species of small mammals were captured. Great Basin pocket mice (Perognathus parvus) comprised the majority of individuals captured, followed by deer mice (Peromyscus maniculatus), Northern pocket gopher (Thomomys talpoides), Western harvest mouse (Reithrodontomys megalotus), Grasshopper mouse (Onychomys leucogaster), Montane vole, (Microtus montanus), House mouse (Mus musculus), and the Bushy-tailed woodrat (Neotoma cinerea). Pocket mice were captured in all habitats sampled; deer mice were obtained in all habitats save hopsage and nearly pure cheatgrass stands. The highese capture rates were found inmore » bitterbrush and riparian habitats. Capture sex ratios for both pocket mice and deer mice were significantly different from equality. Body weights for deer mice and pocket mice exhibited a great deal of heterogeneity across trap sites, although only the heterogeneity for pocket mice was significant. In general, body weights for both species were greater in the sagebrush habitats than elsewhere. These differences are interpreted in light of habitat evaluation methodologies. Six species of reptiles and one species of amphibian were captured. Side-blotched lizards (Uta stansburiana) were by far the most frequently captured species. The predominant snakes captured were the yellow-bellied racer (Coluber constrictor) and the Great Basin gopher snake (Pituophis melanoleucus). Two Great Basin spadefoot toads (Scaphiopus intermontanus) captured at the Rattlesnake Springs trap site. Species diversity was quite low (Shannon-Wiener H )equals) 1.03). Side-blotched lizards were found in all habitats save near the talus on Gable Mountain and on the gravel pad site. The only other lizard species (northern sagebrush lizard (Sceloporus graciosus) and short-horned lizard (Phrynosoma douglasii)) were obtained in bitterbrush habitat. 20 refs., 1 fig

  17. Ghosts of habitats past: Contribution of landscape change to current habitats used by shrubland birds

    USGS Publications Warehouse

    Knick, Steven T.; Rotenberry, J.T.

    2000-01-01

    Models of habitat associations for species often are developed with an implicit assumption that habitats are static, even though recent disturbance may have altered the landscape. We tested our hypothesis that trajectory and magnitude of habitat change influenced observed distribution and abundance of passerine birds breeding in shrubsteppe habitats of southwestern Idaho. Birds in this region live in dynamic landscapes undergoing predominantly large-scale, radical, and unidirectional habitat change because wildfires are converting shrublands into expanses of exotic annual grasslands. We used data from field surveys and satellite image analyses in a series of redundancy analyses to partition variances and to determine the relative contribution of habitat change and current landscapes. Although current habitats explained a greater proportion of total variation, changes in habitat and measures of habitat richness and texture also contributed to variation in abundance of Horned Larks (Eremophila alpestris), Brewera??s Sparrows (Spizella breweri), and Sage Sparrows (Amphispiza belli). Abundance of birds was insensitive to scale for nonspatial habitat variables. In contrast, spatial measures of habitat richness and texture in the landscape were significant only at large spatial scales. Abundance of Horned Larks, Western Meadowlarks (Sturnella neglecta), and Brewera??s Sparrows, but not Sage Thrashers (Oreoscoptes montanus) or Sage Sparrows, was positively correlated with changes toward stable habitats. Because dominant habitat changes were toward less stable conditions, regional declines of those birds in shrubsteppe habitats reflect current landscapes as well as the history, magnitude, and trajectory of habitat change.

  18. Overview of the Distribution, Habitat Association and Impact of Exotic Ants on Native Ant Communities in New Caledonia

    PubMed Central

    Berman, Maïa; Andersen, Alan N.; Hély, Christelle; Gaucherel, Cédric

    2013-01-01

    Ants are among the most ubiquitous and harmful invaders worldwide, but there are few regional studies of their relationships with habitat and native ant communities. New Caledonia has a unique and diverse ant fauna that is threatened by exotic ants, but broad-scale patterns of exotic and native ant community composition in relation to habitat remain poorly documented. We conducted a systematic baiting survey of 56 sites representing the main New Caledonian habitat types: rainforest on ultramafic soils (15 sites), rainforest on volcano-sedimentary soils (13), maquis shrubland (15), Melaleuca-dominated savannas (11) and Acacia spirorbis thickets (2). We collected a total of 49 species, 13 of which were exotic. Only five sites were free of exotic species, and these were all rainforest. The five most abundant exotic species differed in their habitat association, with Pheidole megacephala associated with rainforests, Brachymyrmex cf. obscurior with savanna, and Wasmannia auropunctata and Nylanderia vaga present in most habitats. Anoplolepis gracilipes occurred primarily in maquis-shrubland, which contrasts with its rainforest affinity elsewhere. Multivariate analysis of overall ant species composition showed strong differentiation of sites according to the distribution of exotic species, and these patterns were maintained at the genus and functional group levels. Native ant composition differed at invaded versus uninvaded rainforest sites, in the absence of differences in habitat variables. Generalised Myrmicinae and Forest Opportunists were particularly affected by invasion. There was a strong negative relationship between the abundance of W. auropunctata and native ant abundance and richness. This emphasizes that, in addition to dominating many ant communities numerically, some exotic species, and in particular W. auropunctata, have a marked impact on native ant communities. PMID:23840639

  19. Habitat associations of sympatric red-tailed hawks and northern goshawks on the Kaibab Plateau

    Treesearch

    Frank A. La Sorte; R. William Mannan; Richard T. Reynolds; Teryl G. Grubb

    2004-01-01

    We investigated habitat association of sympatric red-tailed hawks (Buteo jamaicensis) and northern goshawks (Accipiter gentilis) at 2 spatial scales centered on nest sites: (1) fine-scale patterns of forest structure and topography within 16-m radius circles (0.08 ha), and (2) midscale patterns of forested and nonforested areas,...

  20. ANIMAL-HABITAT ASSOCIATIONS IN PACIFIC NORTHWEST ESTUARIES

    EPA Science Inventory

    The mission of the Pacific Coastal Ecology Branch (EPA, Newport, OR) is to determine the effects of habitat alteration by stressors on ecological resources in Pacific Northwest (PNW) estuaries. Research being conducted in support of this mission includes identifying critical hab...

  1. Habitat fragmentation is associated to gut microbiota diversity of an endangered primate: implications for conservation

    PubMed Central

    Barelli, Claudia; Albanese, Davide; Donati, Claudio; Pindo, Massimo; Dallago, Chiara; Rovero, Francesco; Cavalieri, Duccio; Michael Tuohy, Kieran; Christine Hauffe, Heidi; De Filippo, Carlotta

    2015-01-01

    The expansion of agriculture is shrinking pristine forest areas worldwide, jeopardizing the persistence of their wild inhabitants. The Udzungwa red colobus monkey (Procolobus gordonorum) is among the most threatened primate species in Africa. Primarily arboreal and highly sensitive to hunting and habitat destruction, they provide a critical model to understanding whether anthropogenic disturbance impacts gut microbiota diversity. We sampled seven social groups inhabiting two forests (disturbed vs. undisturbed) in the Udzungwa Mountains of Tanzania. While Ruminococcaceae and Lachnospiraceae dominated in all individuals, reflecting their role in extracting energy from folivorous diets, analysis of genus composition showed a marked diversification across habitats, with gut microbiota α-diversity significantly higher in the undisturbed forest. Functional analysis suggests that such variation may be associated with food plant diversity in natural versus human-modified habitats, requiring metabolic pathways to digest xenobiotics. Thus, the effects of changes in gut microbiota should not be ignored to conserve endangered populations. PMID:26445280

  2. Local-Habitat, Watershed, and Biotic Features Associated with Bull Trout Occurrence in Montana Streams

    Treesearch

    C.F. Rich; T.E. McMahon; B.E. Rieman; W.L. Thompson

    2003-01-01

    We evaluated the association of local-habitat features, large-scale watershed factors, the presence of nonnative brook trout Salvelinus fontinalis, and connectivity to neighboring populations with patterns of occurrence of threatened bull trout S. confluentus in 112 first-order to fourthorder streams in the Bitterroot River drainage in western Montana. Species presence...

  3. Nematode-associated microbial taxa do not correlate with host phylogeny, geographic region or feeding morphology in marine sediment habitats.

    PubMed

    Schuelke, Taruna; Pereira, Tiago José; Hardy, Sarah M; Bik, Holly M

    2018-04-01

    Studies of host-associated microbes are critical for advancing our understanding of ecology and evolution across diverse taxa and ecosystems. Nematode worms are ubiquitous across most habitats on earth, yet little is known about host-associated microbial assemblages within the phylum. Free-living nematodes are globally abundant and diverse in marine sediments, with species exhibiting distinct buccal cavity (mouth) morphologies that are thought to play an important role in feeding ecology and life history strategies. Here, we investigated patterns in marine nematode microbiomes, by characterizing host-associated microbial taxa in 281 worms isolated from a range of habitat types (deep-sea, shallow water, methane seeps, Lophelia coral mounds, kelp holdfasts) across three distinct geographic regions (Arctic, Southern California and Gulf of Mexico). Microbiome profiles were generated from single worms spanning 33 distinct morphological genera, using a two-gene metabarcoding approach to amplify the V4 region of the 16S ribosomal RNA (rRNA) gene targeting bacteria/archaea and the V1-V2 region of the 18S rRNA gene targeting microbial eukaryotes. Contrary to our expectations, nematode microbiome profiles demonstrated no distinct patterns either globally (across depths and ocean basins) or locally (within site); prokaryotic and eukaryotic microbial assemblages did not correlate with nematode feeding morphology, host phylogeny or morphological identity, ocean region or marine habitat type. However, fine-scale analysis of nematode microbiomes revealed a variety of novel ecological interactions, including putative parasites and symbionts, and potential associations with bacterial/archaeal taxa involved in nitrogen and methane cycling. Our results suggest that in marine habitats, free-living nematodes may utilize diverse and generalist foraging strategies that are not correlated with host genotype or feeding morphology. Furthermore, some abiotic factors such as geographic region

  4. Epigenetic Differentiation of Natural Populations of Lilium bosniacum Associated with Contrasting Habitat Conditions.

    PubMed

    Zoldoš, Vlatka; Biruš, Ivan; Muratovic, Edina; Šatovic, Zlatko; Vojta, Aleksandar; Robin, Odile; Pustahija, Fatima; Bogunic, Faruk; Vicic Bockor, Vedrana; Siljak-Yakovlev, Sonja

    2018-01-01

    Epigenetic variation in natural populations with contrasting habitats might be an important element, in addition to the genetic variation, in plant adaptation to environmental stress. Here, we assessed genetic, epigenetic, and cytogenetic structure of the three Lilium bosniacum populations growing on distinct habitats. One population was growing under habitual ecological conditions for this species and the other two were growing under stress associated with high altitude and serpentine soil. Amplified fragment length polymorphism and methylation-sensitive amplification polymorphism analyses revealed that the three populations did not differentiate genetically, but were clearly separated in three distinct clusters according to DNA methylation profiles. Principal coordinate analysis showed that overall epigenetic variation was closely related to habitat conditions. A new methylation-sensitive amplification polymorphism scoring approach allowed identification of mainly unmethylated (φST = 0.190) and fully CpG methylated (φST = 0.118) subepiloci playing a role in overall population differentiation, in comparison with hemimethylated sites (φST = 0.073). In addition, unusual rDNA repatterning and the presence of B chromosomes bearing 5S rDNA loci were recorded in the population growing on serpentine soil, suggesting dynamic chromosome rearrangements probably linked to global genome demethylation, which might have reactivated some mobile elements. We discuss our results considering our earlier data on morphology and leaf anatomy of several L. bosniacum populations, and suggest a possible role of epigenetics as a key element in population differentiation associated with environmental stress in these particular lily populations. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  5. Evolution in African tropical trees displaying ploidy-habitat association: The genus Afzelia (Leguminosae).

    PubMed

    Donkpegan, Armel S L; Doucet, Jean-Louis; Migliore, Jérémy; Duminil, Jérôme; Dainou, Kasso; Piñeiro, Rosalía; Wieringa, Jan J; Champluvier, Dominique; Hardy, Olivier J

    2017-02-01

    Polyploidy has rarely been documented in rain forest trees but it has recently been found in African species of the genus Afzelia (Leguminosae), which is composed of four tetraploid rain forest species and two diploid dry forest species. The genus Afzelia thus provides an opportunity to examine how and when polyploidy and habitat shift occurred in Africa, and whether they are associated. In this study, we combined three plastid markers (psbA, trnL, ndhF), two nuclear markers (ribosomal ITS and the single-copy PEPC E7 gene), plastomes (obtained by High Throughput Sequencing) and morphological traits, with an extensive taxonomic and geographic sampling to explore the evolutionary history of Afzelia. Both nuclear DNA and morphological vegetative characters separated diploid from tetraploid lineages. Although the two African diploid species were well differentiated genetically and morphologically, the relationships among the tetraploid species were not resolved. In contrast to the nuclear markers, plastid markers revealed that one of the diploid species forms a well-supported clade with the tetraploids, suggesting historical hybridisation, possibly in relation with genome duplication (polyploidization) and habitat shift from dry to rain forests. Molecular dating based on fossil-anchored gene phylogenies indicates that extant Afzelia started diverging c. 14.5 or 20Ma while extant tetraploid species started diverging c. 7.0 or 9.4Ma according to plastid and nuclear DNA, respectively. Additional studies of tropical polyploid plants are needed to assess whether the ploidy-habitat association observed in African Afzelia would reflect a role of polyploidization in niche divergence in the tropics. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Habitat usage by prairie grouse on the Sheyenne National Grasslands

    Treesearch

    Llewellyn L. Manske; William T. Barker

    1988-01-01

    Prairie grouse habitat usage was observed for six years. Spring and summer habitat usage was primarily in the upland and midland grassland habitat types. Habitat usage shifted during the fall and winter to cropland and associated tree shelterbelts. The switchgrass plant community was the primary concealment cover for nesting and roosting. Cropland and associated tree...

  7. Habitat and fish assemblage associations and current status of northern leatherside chub Lepidomeda copei in western Wyoming

    USGS Publications Warehouse

    Schultz, Luke; Cavalli, Pete; Sexauer, Hilda; Zafft, David

    2016-01-01

    Human activities have extensively altered native fish assemblages and their habitats in the western United States. Conservation and restoration for long-term persistence of these fishes requires knowledge of their distributional patterns and life history requirements. Northern leatherside chub Lepidomeda copei (hereafter northern leatherside) is a cyprinid native to the Snake and Bear River Basins of Wyoming, Idaho, Nevada, and Utah, and it is believed to have declined in distribution relative to historical records. To address information gaps in the species' ecology and assess its status in the state, the objectives of this study were first to document the distribution (2010–2011) of northern leatherside in Wyoming and then to examine habitat factors related to the entire fish assemblage and to evaluate specific habitat associations of northern leatherside in the Bear River Basin, Wyoming. In the Bear River and Upper Snake River Basins, we documented the distribution of northern leatherside and compared it to the previously known distribution. Across the Bear River Basin, we used habitat measurements to assess abiotic features related to the distribution and abundance of northern leatherside. Northern leatherside was found across the Bear River Basin and was present in 2 streams each in the Upper Snake River and Green River Basins in Wyoming. Populations in Wyoming appear to represent the core of northern leatherside range, and our work provided a finer-scale delineation of the species' occurrence. Northern leatherside was collected from a variety of habitats, but multivariate analyses and occurrence modeling indicated it was associated with increased channel depth and depth variability, and positively associated with other native fishes (including mountain sucker Catostomus platyrhynchus, redside shiner Richardsonius balteatus, and speckled dace Rhinichthys osculus). These findings on the distribution and ecology of northern leatherside provide

  8. Habitat and forage associations of a naturally colonising insect pollinator, the tree bumblebee Bombus hypnorum.

    PubMed

    Crowther, Liam P; Hein, Pierre-Louis; Bourke, Andrew F G

    2014-01-01

    Bumblebees (Bombus species) are major pollinators of commercial crops and wildflowers but factors affecting their abundance, including causes of recent population declines, remain unclear. Investigating the ecology of species with expanding ranges provides a potentially powerful means of elucidating these factors. Such species may also bring novel pollination services to their new ranges. We therefore investigated landscape-scale habitat use and foraging preferences of the Tree Bumblebee, B. hypnorum, a recent natural colonist that has rapidly expanded its range in the UK over the past decade. Counts of B. hypnorum and six other Bombus species were made in March-June 2012 within a mixed landscape in south-eastern Norfolk, UK. The extent of different landscape elements around each transect was quantified at three scales (250 m, 500 m and 1500 m). We then identified the landscape elements that best predicted the density of B. hypnorum and other Bombus species. At the best fitting scale (250 m), B. hypnorum density was significantly positively associated with extent of both urban and woodland cover and significantly negatively associated with extent of oilseed rape cover. This combination of landscape predictors was unique to B. hypnorum. Urban and woodland cover were associated with B. hypnorum density at three and two, respectively, of the three scales studied. Relative to other Bombus species, B. hypnorum exhibited a significantly higher foraging preference for two flowering trees, Crataegus monogyna and Prunus spinosa, and significantly lower preferences for Brassica napus, Glechoma hederacea and Lamium album. Our study provides novel, quantitative support for an association of B. hypnorum with urban and woodland landscape elements. Range expansion in B. hypnorum appears to depend, on exploitation of widespread habitats underutilised by native Bombus species, suggesting B. hypnorum will readily co-exist with these species. These findings suggest that management

  9. Spatiotemporal patterns and habitat associations of smallmouth bass (Micropterus dolomieu) invading salmon-rearing habitat

    USGS Publications Warehouse

    Lawrence, David J.; Olden, Julian D.; Torgersen, Christian E.

    2012-01-01

    1. Smallmouth bass (Micropterus dolomieu) have been widely introduced to fresh waters throughout the world to promote recreational fishing opportunities. In the Pacific Northwest (U.S.A.), upstream range expansions of predatory bass, especially into subyearling salmon-rearing grounds, are of increasing conservation concern, yet have received little scientific inquiry. Understanding the habitat characteristics that influence bass distribution and the timing and extent of bass and salmon overlap will facilitate the development of management strategies that mitigate potential ecological impacts of bass.2. We employed a spatially continuous sampling design to determine the extent of bass and subyearling Chinook salmon (Oncorhynchus tshawytscha) sympatry in the North Fork John Day River (NFJDR), a free-flowing river system in the Columbia River Basin that contains an upstream expanding population of non-native bass. Extensive (i.e. 53 km) surveys were conducted over 2 years and during an early and late summer period of each year, because these seasons provide a strong contrast in the river’s water temperature and flow condition. Classification and regression trees were applied to determine the primary habitat correlates of bass abundance at reach and channel-unit scales.3. Our study revealed that bass seasonally occupy up to 22% of the length of the mainstem NFJDR where subyearling Chinook salmon occur, and the primary period of sympatry between these species was in the early summer and not during peak water temperatures in late summer. Where these species co-occurred, bass occupied 60–76% of channel units used by subyearling Chinook salmon in the early summer and 28–46% of the channel units they occupied in the late summer. Because these rearing salmon were well below the gape limitation of bass, this overlap could result in either direct predation or sublethal effects of bass on subyearling Chinook salmon. The upstream extent of bass increased 10–23

  10. Multiscale thermal refugia and stream habitat associations of chinook salmon in northwestern Oregon

    USGS Publications Warehouse

    Torgersen, Christian E.; Price, David M.; Li, Hiram W.; McIntosh, B.A.

    1999-01-01

    We quantified distribution and behavior of adult spring chinook salmon (Oncorhynchus tshawytscha) related to patterns of stream temperature and physical habitat at channel-unit, reach-, and section-level spatial scales in a wilderness stream and a disturbed stream in the John Day River basin in northeastern Oregon. We investigated the effectiveness of thermal remote sensing for analyzing spatial patterns of stream temperature and assessed habitat selection by spring chinook salmon, evaluating whether thermal refugia might be responsible for the persistence of these stocks in rivers where water temperatures frequently exceed their upper tolerance levels (25A?C) during spawning migration. By presenting stream temperature and the ecology of chinook salmon in a historical context, we could evaluate how changes in riverine habitat and thermal spatial structure, which can be caused by land-use practices, may influence distributional patterns of chinook salmon. Thermal remote sensing provided spatially continuous maps of stream temperature for reaches used by chinook salmon in the upper subbasins of the Middle Fork and North Fork John Day River. Electivity analysis and logistic regression were used to test for associations between the longitudinal distribution of salmon and cool-water areas and stream habitat characteristics. Chinook salmon were distributed nonuniformly in reaches throughout each stream. Salmon distribution and cool water temperature patterns were most strongly related at reach-level spatial scales in the warm stream, the Middle Fork (maximum likelihood ratio: P 0.30). Pools were preferred by adult chinook salmon in both subbasins (Bonferroni confidence interval: P a?? 0.05); however, riffles were used proportionately more frequently in the North Fork than in the Middle Fork. Our observations of thermal refugia and their use by chinook salmon at multiple spatial scales reveal that, although heterogeneity in the longitudinal stream temperature profile may

  11. 78 FR 22278 - Proposed Amendment of Habitat Conservation Plan and Associated Documents; Green Diamond Resource...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-15

    ... non-listed species associated with western forests, streams, and wetlands. The northern spotted owl... covered in the existing or proposed amendment to the HCP. Management of northern spotted owls and their... may develop into marbled murrelet and spotted owl habitat over time. No additional buffer areas will...

  12. The forest ecosystem of southeast Alaska: 3. Fish habitats.

    Treesearch

    William R. Meehan

    1974-01-01

    The effects of logging and associated activities on fish habitat in southeastern Alaska are discussed, and fish habitat research applicable to southeast Alaska is summarized. Requirements of salmonids for suitable spawning and rearing areas are presented. Factors associated with timber harvest which may influence these habitats are discussed in detail; e.g., sediment,...

  13. Bee diversity associated with Limnanthes floral patches in California vernal pool habitats

    Treesearch

    Joan M. Leong; Robbin W. Thorp

    2005-01-01

    As with other kinds of wetland habitats in California, approximately 90 percent of vernal pool habitat (estimated) has been lost in California. In southern California, losses are estimated to be even greater. The flora of these endangered habitats is reasonably well known, especially the spring flowering annuals that are found in or at the margins of vernal pools (for...

  14. Invertebrate biomass: Associations with lesser prairie-chicken habitat use and sand sagebrush density in southwestern Kansas

    USGS Publications Warehouse

    Jamison, B.E.; Robel, R.J.; Pontius, J.S.; Applegate, R.D.

    2002-01-01

    Invertebrates are important food sources for lesser prairie-chicken (Tympanuchus pallidicinctus) adults and broods. We compared invertebrate biomass in areas used and not used by lesser prairie-chicken adults and broods. We used radiotelemetry to determine use and non-use areas in sand sagebrush (Artemisia filifolia) prairie in southwestern Kansas and sampled invertebrate populations during summer 1998 and 1999. Sweepnet-collected biomass of short-horned grasshoppers (Acrididae) and total invertebrate biomass generally were greater in habitats used by lesser prairie-chickens than in paired non-use areas. We detected no differences in pitfall-collected biomass of Acrididae (P=0.81) or total invertebrate biomass (P=0.93) among sampling areas with sand sagebrush canopy cover of 0 to 10%, 11 to 30%, and >30%. Results of multivariate analysis and regression model selection suggested that forbs were more strongly associated with invertebrate biomass than shrubs, grasses, or bare ground. We could not separate lesser prairie-chicken selection for areas of forb cover from selection of areas with greater invertebrate biomass associated with forb cover. Regardless of whether the effects of forbs were direct or indirect, their importance in sand sagebrush habitat has management implications. Practices that maintain or increase forb cover likely will increase invertebrate biomass and habitat quality in southwestern Kansas.

  15. Invertebrate biomass: associations with lesser prairie-chicken habitat use and sand sagebrush density in southwestern Kansas

    USGS Publications Warehouse

    Jamison, B.; Robel, R.J.; Pontius, J.S.; Applegate, R.D.

    2002-01-01

    Invertebrates are important food sources for lesser prairie-chicken (Tympanuchus pallidicinctus) adults and broods. We compared invertebrate biomass in areas used and not used by lesser prairie-chicken adults and broods. We used radiotelemetry to determine use and non-use areas in sand sagebrush (Artemisia filifolia) prairie in southwestern Kansas and sampled invertebrate populations during summer 1998 and 1999. Sweepnet-collected biomass of short-horned grasshoppers (Acrididae) and total invertebrate biomass generally were greater in habitats used by lesser prairie-chickens than in paired non-use areas. We detected no differences in pitfall-collected biomass of Acrididae (P=0.81) or total invertebrate biomass (P=0.93) among sampling areas with sand sagebrush canopy cover of 0 to 10%, 11 to 30%, and >30%. Results of multivariate analysis and regression model selection suggested that forbs were more strongly associated with invertebrate biomass than shrubs, grasses, or bare ground. We could not separate lesser prairie-chicken selection for areas of forb cover from selection of areas with greater invertebrate biomass associated with forb cover. Regardless of whether the effects of forbs were direct or indirect, their importance in sand sagebrush habitat has management implications. Practices that maintain or increase forb cover likely will increase invertebrate biomass and habitat quality in southwestern Kansas.

  16. Avian habitat relationships in pinyon-juniper woodland

    USGS Publications Warehouse

    Sedgwick, James A.

    1987-01-01

    Habitat relationships of breeding birds were examined in northwestern Colorado in pinyon-juniper (Pinus edulis-Juniperus osteosperma) woodland and in openings where most overstory trees had been knocked down by anchor chaining. Vegetation characteristics and physical habitat features were measured in 233 0.04-ha circular plots around singing males of 13 species of birds from 15 May to 15 July 1980. Thirteen-group discriminant function analysis ordinated bird species along three habitat dimensions described by (1) canopy height; (2) slope, shrub size, and shrub species diversity; and (3) percentage canopy cover, large tree density, distance from a habitat edge, litter cover, and green cover. Woodland, open-area, and intermediate edge species were clearly segregated along the first discriminant axis, and species' associations with shrubs, inclination, ground cover, and edges were revealed by the ordinations along the second and third discriminant axes. Two-group discriminant analyses comparing occupied and available plots identified additional and more specific habitat associations. For example, Hermit Thrushes (Catharus guttatus) were associated with mature forested habitats and forest interiors, Virginia's Warblers (Vermivora virginiae) favored steep, oak-covered draws, Rock Wrens (Salpinctes obsoletus) selected areas where percentage log cover and small tree density were high, and Dusky Flycatchers (Empidonax oberholseri) preferred shrubby slopes with scattered large trees near woodland edges.

  17. Mass Spectrometry-Based Visualization of Molecules Associated with Human Habitats.

    PubMed

    Petras, Daniel; Nothias, Louis-Félix; Quinn, Robert A; Alexandrov, Theodore; Bandeira, Nuno; Bouslimani, Amina; Castro-Falcón, Gabriel; Chen, Liangyu; Dang, Tam; Floros, Dimitrios J; Hook, Vivian; Garg, Neha; Hoffner, Nicole; Jiang, Yike; Kapono, Clifford A; Koester, Irina; Knight, Rob; Leber, Christopher A; Ling, Tie-Jun; Luzzatto-Knaan, Tal; McCall, Laura-Isobel; McGrath, Aaron P; Meehan, Michael J; Merritt, Jonathan K; Mills, Robert H; Morton, Jamie; Podvin, Sonia; Protsyuk, Ivan; Purdy, Trevor; Satterfield, Kendall; Searles, Stephen; Shah, Sahil; Shires, Sarah; Steffen, Dana; White, Margot; Todoric, Jelena; Tuttle, Robert; Wojnicz, Aneta; Sapp, Valerie; Vargas, Fernando; Yang, Jin; Zhang, Chao; Dorrestein, Pieter C

    2016-11-15

    The cars we drive, the homes we live in, the restaurants we visit, and the laboratories and offices we work in are all a part of the modern human habitat. Remarkably, little is known about the diversity of chemicals present in these environments and to what degree molecules from our bodies influence the built environment that surrounds us and vice versa. We therefore set out to visualize the chemical diversity of five built human habitats together with their occupants, to provide a snapshot of the various molecules to which humans are exposed on a daily basis. The molecular inventory was obtained through untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of samples from each human habitat and from the people that occupy those habitats. Mapping MS-derived data onto 3D models of the environments showed that frequently touched surfaces, such as handles (e.g., door, bicycle), resemble the molecular fingerprint of the human skin more closely than other surfaces that are less frequently in direct contact with humans (e.g., wall, bicycle frame). Approximately 50% of the MS/MS spectra detected were shared between people and the environment. Personal care products, plasticizers, cleaning supplies, food, food additives, and even medications that were found to be a part of the human habitat. The annotations indicate that significant transfer of chemicals takes place between us and our built environment. The workflows applied here will lay the foundation for future studies of molecular distributions in medical, forensic, architectural, space exploration, and environmental applications.

  18. WATERFOWL-HABITAT ASSOCIATIONS DURING WINTER IN A URBAN NORTH ATLANTIC ESTUARY

    EPA Science Inventory

    Coastal habitats near urban centres in North Atlantic estuaries often support substantial numbers of wintering waterfowl, but little is known of the effects of landscape setting and urbanisation on habitat use. We conducted surveys of waterfowl at 32 wintering sites in Narraganse...

  19. Is the microplastic selective according to the habitat? Records in amphioxus sands, Mäerl bed habitats and Cymodocea nodosa habitats.

    PubMed

    Renzi, Monia; Blašković, Andrea; Fastelli, Paolo; Marcelli, Massimiliano; Guerranti, Cristiana; Cannas, Susanna; Barone, Lorenzo; Massara, Francesca

    2018-05-01

    This study estimated for the first time the total loads of plastic litter (macro- meso- and micro-plastics) in sediments of different habitat types from the Northern Adriatic Sea. Samples were collected in March 2016. The sampling sites were settled in shoreline, on the C. nodosa bottoms, Amphioxus sands, and Mäerl bed habitats. Microplastics items were present in all sampling site and ranging within 137-703 items/kg d.w. from Mäerl bed habitat to the shoreline. In C. nodosa bottoms 170 items/kg d.w. were found, while in Amphioxus sands were recorded on average 194 items/kg d.w. Due to the absence of statistical associations among litter levels and abundance of B. lanceolatum in the study area, this research present the needs to develop a new method and more research to for the evaluation of how much the interrelation between sensible habitats and microplastic exist. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. A comparison of avian communities and habitat characteristics in floodplain forests associated with valley plugs and unchannelized streams

    USGS Publications Warehouse

    Pierce, Aaron R.; King, Sammy L.

    2011-01-01

    Channelization of streams associated with floodplain forested wetlands has occurred extensively throughout the world and specifically in the southeastern United States. Channelization of fluvial systems alters the hydrologic and sedimentation processes that sustain these systems. In western Tennessee, channelization and past land-use practices have caused drastic geomorphic and hydrologic changes, resulting in altered habitat conditions that may affect avian communities. The objective of this study was to determine if there were differences in avian communities utilizing floodplain forests along unchannelized streams compared to channelized streams with valley plugs, areas where sediment has completely filled the channel. During point count surveys, 58 bird species were observed at unchannelized sites and 60 species were observed at valley plug sites. Species associated with baldcypress-tupelo (Taxodium-Nyssa) swamps (e.g. Great Egret (Ardea albus) and Black-crowned Night Heron (Nycticorax nycticorax)) and mature hardwood forests with open midstories (e.g. Eastern Wood-Pewee (Contopus virens), Yellow-throated Vireo (Vireo flavifrons), Cerulean Warbler (Dendroica cerulea) and Scarlet Tanager (Piranga olivacea)) were either only found at unchannelized sites or were more abundant at unchannelized sites. Conversely, species associated with open and early successional habitats (e.g. Tree Swallow (Tachycineta bicolor), Northern Mockingbird (Mimus polyglottos) and Blue Grosbeak (Passerina caerulea)) were either only found at valley plug sites or were more abundant at valley plug sites. Results of habitat modelling suggest that the habitat characteristics of floodplain forests at unchannelized sites are more suitable for Neotropical migrant bird species of conservation concern in the region than at valley plug sites. This study, in combination with previous research, demonstrates the ecological impacts of valley plugs span across abiotic and biotic processes and tropic

  1. Modeling sensitive elasmobranch habitats

    NASA Astrophysics Data System (ADS)

    Pennino, M. Grazia; Muñoz, Facundo; Conesa, David; López-Quílez, Antonio; Bellido, José Marí; a

    2013-10-01

    Basic information on the distribution and habitat preferences of ecologically important species is essential for their management and protection. In the Mediterranean Sea there is increasing concern over elasmobranch species because their biological (ecological) characteristics make them highly vulnerable to fishing pressure. Their removal could affect the structure and function of marine ecosystems, inducing changes in trophic interactions at the community level due to the selective elimination of predators or prey species, competitors and species replacement. In this study Bayesian hierarchical spatial models are used to map the sensitive habitats of the three most caught elasmobranch species (Galeus melastomus, Scyliorhinus canicula, Etmopterus spinax) in the western Mediterranean Sea, based on fishery-dependent bottom trawl data. Results show that habitats associated with hard substrata and sandy beds, mainly in deep waters and with a high seabed gradient, have a greater probability registering the presence of the studied species than those associated with muddy shallow waters. Temperature and chlorophyll-α concentration show a negative relationship with S. canicula occurrence. Our results identify some of the sensitive habitats for elasmobranchs in the western Mediterranean Sea (GSA06 South), providing essential and easy-to-use interpretation tools, such as predictive distribution maps, with the final aim of improving management and conservation of these vulnerable species.

  2. Habitat use of the European mudminnow Umbra krameri and association with other fish species in a disconnected Danube side arm.

    PubMed

    Sehr, M; Keckeis, H

    2017-10-01

    Fish assemblages along the longitudinal course of an old, disconnected and modified side arm of the Danube floodplain downstream of Vienna, Austria, as well as habitat structure, hydro-morphological and hydro-chemical factors, were investigated in order to analyse the key environmental determinants of the European mudminnow Umbra krameri. Generally, U. krameri was the most abundant species in the system. It occurred in disconnected ditches, ponds and pools with dense reed belts and comparatively low nutrient content, indicating its natural association with marsh habitats. At infrequently disturbed sites it was associated with a small group of stagnophilious and highly specialized species with adaptations to strong oxygen fluctuations. At frequently flooded sites, the species was absent or occurred in low abundances, indicating its adaptation to water bodies in older successional stages and its low competitive power in permanently connected floodplain habitats. © 2017 The Fisheries Society of the British Isles.

  3. Forest habitat loss, fragmentation, and red-cockaded woodpecker populations

    Treesearch

    Richard N. Conner; D. Craig Rudolph

    1991-01-01

    Loss of mature forest habitat was measured around Red-cockaded Woodpecker (Picoides borealis) cavity tree clusters (colonies) in three National Forests in eastern Texas. Forest removal results in a loss of foraging habitat and causes habitat fragmentation of the remaining mature forest. Habitat loss was negatively associated with woodpecker group size in small...

  4. Assessing juvenile salmon rearing habitat and associated predation risk in a lower Snake River reservoir

    USGS Publications Warehouse

    Tiffan, Kenneth F.; Hatten, James R.; Trachtenbarg, David A

    2015-01-01

    Subyearling fall Chinook salmon (Oncorhynchus tshawytscha) in the Columbia River basin exhibit a transient rearing strategy and depend on connected shoreline habitats during freshwater rearing. Impoundment has greatly reduced the amount of shallow-water rearing habitat that is exacerbated by the steep topography of reservoirs. Periodic dredging creates opportunities to strategically place spoils to increase the amount of shallow-water habitat for subyearlings while at the same time reducing the amount of unsuitable area that is often preferred by predators. We assessed the amount and spatial arrangement of subyearling rearing habitat in Lower Granite Reservoir on the Snake River to guide future habitat improvement efforts. A spatially explicit habitat assessment was conducted using physical habitat data, two-dimensional hydrodynamic modelling and a statistical habitat model in a geographic information system framework. We used field collections of subyearlings and a common predator [smallmouth bass (Micropterus dolomieu)] to draw inferences about predation risk within specific habitat types. Most of the high-probability rearing habitat was located in the upper half of the reservoir where gently sloping landforms created low lateral bed slopes and shallow-water habitats. Only 29% of shorelines were predicted to be suitable (probability >0.5) for subyearlings, and the occurrence of these shorelines decreased in a downstream direction. The remaining, less suitable areas were composed of low-probability habitats in unmodified (25%) and riprapped shorelines (46%). As expected, most subyearlings were found in high-probability habitat, while most smallmouth bass were found in low-probability locations. However, some subyearlings were found in low-probability habitats, such as riprap, where predation risk could be high. Given their transient rearing strategy and dependence on shoreline habitats, subyearlings could benefit from habitat creation efforts in the lower

  5. Fish assemblage structure and habitat associations in a large western river system

    USGS Publications Warehouse

    Smith, C.D.; Quist, Michael C.; Hardy, R. S.

    2016-01-01

    Longitudinal gradients of fish assemblage and habitat structure were investigated in the Kootenai River of northern Idaho. A total of 43 500-m river reaches was sampled repeatedly with several techniques (boat-mounted electrofishing, hoop nets and benthic trawls) in the summers of 2012 and 2013. Differences in habitat and fish assemblage structure were apparent along the longitudinal gradient of the Kootenai River. Habitat characteristics (e.g. depth, substrate composition and water velocity) were related to fish assemblage structure in three different geomorphic river sections. Upper river sections were characterized by native salmonids (e.g. mountain whitefish Prosopium williamsoni), whereas native cyprinids (peamouth Mylocheilus caurinus, northern pikeminnow Ptychocheilus oregonensis) and non-native fishes (pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens) were common in the downstream section. Overall, a general pattern of species addition from upstream to downstream sections was discovered and is likely related to increased habitat complexity and additions of non-native species in downstream sections. Assemblage structure of the upper sections were similar, but were both dissimilar to the lower section of the Kootenai River. Species-specific hurdle regressions indicated the relationships among habitat characteristics and the predicted probability of occurrence and relative abundance varied by species. Understanding fish assemblage structure in relation to habitat could improve conservation efforts of rare fishes and improve management of coldwater river systems.

  6. EXAMINING ASSOCIATIONS BETWEEN FISH ASSEMBLAGES AND PHYSICAL HABITAT

    EPA Science Inventory

    Assessing lotic fish-habitat interactions from regional survey data requires that we consider a comprehensive representation, at the appropriate scale, of the likely controls on fish assemblages. At the scale of stream and river reaches, the important dimensions of physical habi...

  7. Chapter 2. Methods and terminology used with studies of habitat associations

    Treesearch

    D. Archibald McCallum

    1994-01-01

    The forest owl conservation assessments emphasize the relationship between flammulated, boreal, and great gray owls and the forests in which they occur. The habitat requirements of the owls and their principal prey bear strongly on the conservation status of the owls. Establishing the characteristics of the owl/habitat relationship is not a trivial or straightforward...

  8. Diversity and associations between coastal habitats and anurans in southernmost Brazil.

    PubMed

    Oliveira, Mauro C L M; Dos Santos, Maurício B; Loebmann, Daniel; Hartman, Alexandre; Tozetti, Alexandro M

    2013-01-01

    This study aimed to verify the relationship between habitat and the composition of anuran species in dune and restinga habitats in southernmost Brazil. The habitats were sampled between April 2009 and March 2010 using pitfalls with drift fence. We have captured 13,508 individuals of 12 anuran species. Species richness was lower in the dunes and dominance was higher in the resting. Apparently the less complex plant cover, water availability, and wide daily thermal variation in dunes act as an environmental filter for frogs. This hypothesis is reinforced by the fact that the most abundant species (Physalaemus biligonigerus and Odonthoprynus maisuma) bury themselves in the sand, minimizing these environmental stresses. Despite being in the Pampa biome, the studied community was more similar to those of coastal restinga environment of southeast Brazil than with other of the Pampa biome. The number of recorded species is similar to those observed in other open habitats in Brazil, showing the importance of adjacent ones to the shoreline for the maintenance of the diversity of anurans in southernmost Brazil.

  9. Genetic differentiation in Elaeocarpus photiniifolia (Elaeocarpaceae) associated with geographic distribution and habitat variation in the Bonin (Ogasawara) Islands.

    PubMed

    Sugai, Kyoko; Setsuko, Suzuki; Nagamitsu, Teruyoshi; Murakami, Noriaki; Kato, Hidetoshi; Yoshimaru, Hiroshi

    2013-11-01

    Gene flow between populations in different environmental conditions can be limited due to divergent natural selection, thus promoting genetic differentiation. Elaeocarpus photiniifolia, an endemic tree species in the Bonin Islands, is distributed in two types of habitats, dry scrubs and mesic forests. We aim to elucidate the genetic differentiation in E. photiniifolia within and between islands and between the habitat types. We investigated genotypes of 639 individuals from 19 populations of E. photiniifolia and its closely-related E. sylvestris at 24 microsatellite loci derived from expressed sequence tags. The data revealed genetic differentiation (1) between E. photiniifolia and E. sylvestris (0.307 ≤ F ST ≤ 0.470), (2) between the E. photiniifolia populations of the Chichijima and Hahajima Island Groups in the Bonin Islands (0.033 ≤ F ST ≤ 0.121) and (3) between E. photiniifolia populations associated with dry scrubs and mesic forests in the Chichijima Island Group (0.005 ≤ F ST ≤ 0.071). Principal coordinate analysis and Bayesian clustering analysis also showed that genetically distinct groups were associated with the habitat types, and isolation by distance was not responsible for the genetic differentiation. These findings suggest that E. photiniifolia is divided into genetically differentiated groups associated with different environmental conditions in the Bonin Islands.

  10. Physical habitat and water quality correlates of crayfish distributions in a mined watershed

    USGS Publications Warehouse

    Welsh, Stuart A.; Loughman, Zachary J.

    2014-01-01

    In mined watersheds, water quality alters aquatic faunas, but few studies have focused on associations between stream habitat and crayfish distributions. We examined associations of water quality and physical habitat quality on presence/absence of six crayfish species in the upper Kanawha River drainage of southern West Virginia, USA, a region with a long history of surface and mountaintop removal mining of coal. Data supported an association of physical habitat quality with the presence of four species (Cambarus carinirostris, Cambarus robustus, Cambarus cf. sciotensis, and Orconectes sanbornii). Cambarus bartonii cavatus and the non-native Orconectes virilis were associated with lower quality physical habitat than that of the other four species. Relative to other species, C. b. cavatus was associated with the lowest conductivity values, whereas O. virilis was associated with the highest conductivity values. Secondary and tertiary burrowers were generally associated with relatively high-quality physical habitat. However, C. b. cavatus, a crayfish known to burrow extensively in headwater streams, was associated with the lowest quality physical habitat. Physical habitat quality was generally supported over stream conductivity as a variable influencing crayfish distributions. Our data demonstrate the importance of stream habitat quality when assessing crayfish assemblages within mined watersheds.

  11. Evaluation of physicochemical and physical habitat associations for Cambarus callainus (Big Sandy crayfish), an imperilled crayfish endemic to the Central Appalachians

    USGS Publications Warehouse

    Loughman, Zachary J.; Welsh, Stuart A.; Sadecky, Nicole M.; Dillard, Zachary W.; Scott, R. Katie

    2017-01-01

    1. Crayfish represent one of the most imperilled animal groups on the planet. Habitat degradation, destruction and fragmentation, introduction of invasive crayfishes, and a lack of applied biological information have all been identified as agents thwarting crayfish conservation.2. Cambarus callainus was warranted federal protection by the United States Fish and Wildlife Service (USFWS) in April, 2016. As part of the USFWS listing procedure, a survey for C. callainus in the Big Sandy River catchment was conducted to determine points of occurrence with a secondary objective of determining reach level physical habitat and physicochemical correlates of C. callainus presence and absence.3. At each site, physicochemical and physical habitat data were collected to determine the influence of abiotic covariates on the presence of C. callainus. Cambarus callainus presence or absence and associated site covariates were modelled using logistic regression.4. Survey results recorded C. callainus at 39 sites in the Upper Levisa Fork (ULF) and Tug Fork (TF) drainages of the Big Sandy River; no C. callainus were collected in the Lower Levisa Fork (LLF). An additive effects model of physical habitat quality (Basin + Boulder presence/embeddedness) was the only model selected, supporting an association of C. callainus with slab boulders, open interstitial spaces, and moderate to no sedimentation. All sites lacking C. callainus were experiencing some degree of sedimentation. Physicochemical covariates were not supported by the data.5. Results indicated that good quality habitat was lacking in the LLF, but was present in the ULF and TF catchments, with ULF supporting the most robust populations and most suitable habitat. Effective conservation for C. callainus should focus on efforts that limit sedimentation as well as restore good quality instream habitat in the greater Big Sandy catchment.

  12. Secretive marsh aird species co-eccurrences and habitat associations across the midwest, USA

    USGS Publications Warehouse

    Bolenbaugh, Jason R.; Krementz, David G.; Lehnen, Sarah E.

    2011-01-01

    Because secretive marsh birds are difficult to detect, population status and habitat use for these birds are not well known. We conducted repeated surveys for secretive marsh birds across 264 sites in the Upper Mississippi River and Great Lakes Joint Venture region to estimate abundance, occupancy, and detection probabilities during the 2008 and 2009 breeding seasons. We identified species groups based on observed species co-occurrences. Two species, least bittern Ixobrychus exilis and American bittern Botaurus lentiginosus, co-occurred with other species less often than expected by chance, and two species groups, rails (Virginia rail Rallus limicola and sora Porzana carolina) and open-water birds (pied-billed grebe Podilymbus podiceps, common moorhen Gallinula chloropus, and American coot Fulica americana; coots were only surveyed in 2009), co-occurred more often than expected by chance. These groupings were consistent between years. We then estimated the relation of these species and groups to landscape and local site characteristics by using zero-inflated abundance models that accounted for incomplete detection. At the landscape level (5-km radius), the amount of emergent herbaceous wetland was positively associated with least bittern occupancy, whereas the amount of woody wetland was negatively associated with least bittern, rail, and open-water bird occupancy. At the local level, habitat variables that were associated with abundance were not consistent among groups or between years, with the exception that both least bitterns and open-water birds had a strong positive association between abundance and water-vegetation interspersion. Land managers interested in marsh bird management or conservation may want to consider focusing efforts on landscapes with high amounts of emergent herbaceous wetland and low amounts of woody wetland, and managing for high amounts of water-vegetation interspersion within the wetland.

  13. Habitat Association and Seasonality in a Mosaic and Bimodal Hybrid Zone between Chorthippus brunneus and C. jacobsi (Orthoptera: Acrididae)

    PubMed Central

    Tatsuta, Haruki; Butlin, Roger K.

    2012-01-01

    Understanding why some hybrid zones are bimodal and others unimodal can aid in identifying barriers to gene exchange following secondary contact. The hybrid zone between the grasshoppers Chorthippus brunneus and C. jacobsi contains a mix of allopatric parental populations and inter-mingled bimodal and unimodal sympatric populations, and provides an ideal system to examine the roles of local selection and gene flow between populations in maintaining bimodality. However, it is first necessary to confirm, over a larger spatial scale, previously identified associations between population composition and season and habitat. Here we use cline-fitting of one morphological and one song trait along two valley transects, and intervening mountains, to confirm previously identified habitat associations (mountain versus valley) and seasonal changes in population composition. As expected from previous findings of studies on a smaller spatial scale, C. jacobsi dominated mountain habitats and mixed populations dominated valleys, and C. brunneus became more prevalent in August. Controlling for habitat and incorporating into the analysis seasonal changes in cline parameters and the standard errors of parental trait values revealed wider clines than previous studies (best estimates of 6.4 to 24.5 km in our study versus 2.8 to 4.7 km in previous studies) and increased percentage of trait variance explained (52.7% and 61.5% for transects 1 and 2 respectively, versus 17.6%). Revealing such strong and consistent patterns within a complex hybrid zone will allow more focused examination of the causes of variation in bimodality in mixed populations, in particular the roles of local selection versus habitat heterogeneity and gene flow between differentiated populations. PMID:22675485

  14. Geomorphology and Sustainable Subsistence Habitats

    NASA Astrophysics Data System (ADS)

    Johnson, A. C.; Kruger, L. E.

    2016-02-01

    Climatic, tectonic, and human-related impacts are changing the distribution of shoreline habitats and associated species used as food resources. There is a need to summarize current and future shoreline geomorphic - biotic relationships and better understand potential impacts to native customary and traditional gathering patterns. By strategically integrating Native knowledge and observations, we create an inclusive vulnerability assessment strategy resulting in a win-win opportunity for resource users and research scientists alike. We merged the NOAA ShoreZone database with results from over sixty student intern discussions in six southeast Alaska Native communities. Changes in shore width and unit length were derived using near shore bathymetry depths and available isostatic rebound, tectonic movement, and rates of sea level rise. Physical attributes including slope, substrate, and exposure were associated with presence and abundance of specific species. Student interns, selected by Tribes and Tribal associations, conducted resource-based discussions with community members to summarize species use, characteristics of species habitat, transportation used to access collection areas, and potential threats to habitats. Geomorphic trends and community observations were summarized to assess potential threats within a spatial context. Given current measured rates of uplift and sea level rise, 2.4 to 0 m of uplift along with 0.20 m of sea level rise is expected in the next 100 years. Coastlines of southeast Alaska will be subject to both drowning (primarily to the south) and emergence (primarily to the north). We predict decreases in estuary and sediment-dominated shoreline length and an increase in rocky habitats. These geomorphic changes, combined with resident's concerns, highlight six major interrelated coastal vulnerabilities including: (1) reduction of clam and clam habitat quantity and quality, (2) reduction in chiton quality and quantity, (3) harmful expansion of

  15. The influence of habitat on the evolution of plants: a case study across Saxifragales

    PubMed Central

    de Casas, Rafael Rubio; Mort, Mark E.; Soltis, Douglas E.

    2016-01-01

    Background and Aims Organismal evolution tends to be closely associated with ecological conditions. However, the extent to which this association constrains adaptation or diversification into new habitats remains unclear. We studied habitat evolution in the hyper-diverse angiosperm clade Saxifragales. Methods We used species-level phylogenies for approx. 950 species to analyse the evolution of habitat shifts as well as their influence on plant diversification. We combined habitat characterization based on floristic assignments and state-of-the art phylogenetic comparative methods to estimate within- and across-habitat diversification patterns. Key Results Our analyses showed that Saxifragales diversified into multiple habitats from a forest-inhabiting ancestor and that this diversification is governed by relatively rare habitat shifts. Lineages are likely to stay within inferred ancestral ecological conditions. Adaptation to some habitat types (e.g. aquatic, desert) may be canalizing events that lineages do not escape. Although associations between increased diversification rates and shifts in habitat preferences are occasionally observed, extreme macroevolutionary rates are closely associated with specific habitats. Lineages occurring in shrubland, and especially tundra and rock cliffs, exhibit comparatively high diversification, whereas forest, grassland, desert and aquatic habitats are associated with low diversification. Conclusions The likelihood of occupation of new habitats appears to be asymmetric. Shifts to aquatic and desert habitats may be canalizing events. Other habitats, such as tundra, might act as evolutionary sources, while forests provide the only habitat seemingly colonized easily by lineages originating elsewhere. However, habitat shifts are very rare, and any major environmental alteration is expected to have dramatic evolutionary consequences. PMID:27551029

  16. Habitat features and predictive habitat modeling for the Colorado chipmunk in southern New Mexico

    USGS Publications Warehouse

    Rivieccio, M.; Thompson, B.C.; Gould, W.R.; Boykin, K.G.

    2003-01-01

    Two subspecies of Colorado chipmunk (state threatened and federal species of concern) occur in southern New Mexico: Tamias quadrivittatus australis in the Organ Mountains and T. q. oscuraensis in the Oscura Mountains. We developed a GIS model of potentially suitable habitat based on vegetation and elevation features, evaluated site classifications of the GIS model, and determined vegetation and terrain features associated with chipmunk occurrence. We compared GIS model classifications with actual vegetation and elevation features measured at 37 sites. At 60 sites we measured 18 habitat variables regarding slope, aspect, tree species, shrub species, and ground cover. We used logistic regression to analyze habitat variables associated with chipmunk presence/absence. All (100%) 37 sample sites (28 predicted suitable, 9 predicted unsuitable) were classified correctly by the GIS model regarding elevation and vegetation. For 28 sites predicted suitable by the GIS model, 18 sites (64%) appeared visually suitable based on habitat variables selected from logistic regression analyses, of which 10 sites (36%) were specifically predicted as suitable habitat via logistic regression. We detected chipmunks at 70% of sites deemed suitable via the logistic regression models. Shrub cover, tree density, plant proximity, presence of logs, and presence of rock outcrop were retained in the logistic model for the Oscura Mountains; litter, shrub cover, and grass cover were retained in the logistic model for the Organ Mountains. Evaluation of predictive models illustrates the need for multi-stage analyses to best judge performance. Microhabitat analyses indicate prospective needs for different management strategies between the subspecies. Sensitivities of each population of the Colorado chipmunk to natural and prescribed fire suggest that partial burnings of areas inhabited by Colorado chipmunks in southern New Mexico may be beneficial. These partial burnings may later help avoid a fire

  17. Habitat fragmentation in the temperate zone: a perspective for managers

    Treesearch

    John Faaborg; Margaret Brittingham; Therese Donovan; John Blake

    1993-01-01

    Habitat fragmentation occurs when a large, fairly continuous tract of vegetation is converted to other vegetation types such that only scattered fragments of the original type remain. Problems associated with habitat fragmentation include overall habitat loss, increase in edge habitat and edge effects (particularly higher parasitism and nest predation rates), and...

  18. Naturalization of European plants on other continents: The role of donor habitats.

    PubMed

    Kalusová, Veronika; Chytrý, Milan; van Kleunen, Mark; Mucina, Ladislav; Dawson, Wayne; Essl, Franz; Kreft, Holger; Pergl, Jan; Weigelt, Patrick; Winter, Marten; Pyšek, Petr

    2017-12-26

    The success of European plant species as aliens worldwide is thought to reflect their association with human-disturbed environments. However, an explicit test including all human-made, seminatural and natural habitat types of Europe, and their contributions as donor habitats of naturalized species to the rest of the globe, has been missing. Here we combine two databases, the European Vegetation Checklist and the Global Naturalized Alien Flora, to assess how human influence in European habitats affects the probability of naturalization of their plant species on other continents. A total of 9,875 native European vascular plant species were assigned to 39 European habitat types; of these, 2,550 species have become naturalized somewhere in the world. Species that occur in both human-made habitats and seminatural or natural habitats in Europe have the highest probability of naturalization (64.7% and 64.5% of them have naturalized). Species associated only with human-made or seminatural habitats still have a significantly higher probability of becoming naturalized (41.7% and 28.6%, respectively) than species confined to natural habitats (19.4%). Species associated with arable land and human settlements were recorded as naturalized in the largest number of regions worldwide. Our findings highlight that plant species' association with native-range habitats disturbed by human activities, combined with broad habitat range, play an important role in shaping global patterns of plant invasions.

  19. Beyond habitat structure: Landscape heterogeneity explains the monito del monte (Dromiciops gliroides) occurrence and behavior at habitats dominated by exotic trees.

    PubMed

    Salazar, Daniela A; Fontúrbel, Francisco E

    2016-09-01

    Habitat structure determines species occurrence and behavior. However, human activities are altering natural habitat structure, potentially hampering native species due to the loss of nesting cavities, shelter or movement pathways. The South American temperate rainforest is experiencing an accelerated loss and degradation, compromising the persistence of many native species, and particularly of the monito del monte (Dromiciops gliroides Thomas, 1894), an arboreal marsupial that plays a key role as seed disperser. Aiming to compare 2 contrasting habitats (a native forest and a transformed habitat composed of abandoned Eucalyptus plantations and native understory vegetation), we assessed D. gliroides' occurrence using camera traps and measured several structural features (e.g. shrub and bamboo cover, deadwood presence, moss abundance) at 100 camera locations. Complementarily, we used radio telemetry to assess its spatial ecology, aiming to depict a more complete scenario. Moss abundance was the only significant variable explaining D. gliroides occurrence between habitats, and no structural variable explained its occurrence at the transformed habitat. There were no differences in home range, core area or inter-individual overlapping. In the transformed habitats, tracked individuals used native and Eucalyptus-associated vegetation types according to their abundance. Diurnal locations (and, hence, nesting sites) were located exclusively in native vegetation. The landscape heterogeneity resulting from the vicinity of native and Eucalyptus-associated vegetation likely explains D. gliroides occurrence better than the habitat structure itself, as it may be use Eucalyptus-associated vegetation for feeding purposes but depend on native vegetation for nesting. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  20. Habitat assessment, Missouri River at Hermann, Missouri

    USGS Publications Warehouse

    Jacobson, Robert B.; Laustrup, Mark S.; Reuter, Joanna M.

    2002-01-01

    This report documents methods and results of aquatic habitat assessment in the Missouri River near Hermann, Missouri. The assessment is intended to improve understanding of spatial and temporal variability of aquatic habitat, including habitats thought to be critical for the endangered pallid sturgeon (Scaphirhynchus albus). Physical aquatic habitat - depth, velocity, and substrate - was assessed around 9 wing dikes and adjacent to the U.S. Route 19 bridge, at discharges varying from 44,000 cubic feet per second (cfs) to 146, 000 cfs during August 2000-May, 2001. For the river as a whole, velocities are bi-modally distributed with distinct peaks relating to navigation channel and wing-dike environments. Velocities predictably showed an increasing trend with increasing discharge. Substrate within wing dikes was dominated by mud at low discharges, whereas the navigation channel had patches of transporting sand, rippled sand, and coarse sand. Discharges that overtopped the wing dikes (about 93,000 cfs, March 2001) were associated with increases of patchy sand, rippled sand, and coarse sand within the wing dikes. When flows were substantially over the wing dikes (146,000 cfs, May 2001) substrates within most wing dikes showed substantial reorganization and coarsening. The habitat assessment provides a geospatial database that can be used to query wing dikes for distributions of depth, velocity, and substrate for comparison with fish samples collected by US Fish and Wildlife Service biologists (Grady and others, 2001). In addition, the assessment documented spatial and temporal variation in habitat within the Hermann reach and over a range of discharges. Measurable geomorphic change--alteration of substrate conditions plus substantial erosion and deposition--was associated with flows equaled or exceeded 12-40% of the time (40-140 days per year). Documented geomorphic change associated with high-frequency flows underscores the natural temporal variability of physical

  1. The influence of habitat on the evolution of plants: a case study across Saxifragales.

    PubMed

    de Casas, Rafael Rubio; Mort, Mark E; Soltis, Douglas E

    2016-12-01

    Organismal evolution tends to be closely associated with ecological conditions. However, the extent to which this association constrains adaptation or diversification into new habitats remains unclear. We studied habitat evolution in the hyper-diverse angiosperm clade Saxifragales. We used species-level phylogenies for approx. 950 species to analyse the evolution of habitat shifts as well as their influence on plant diversification. We combined habitat characterization based on floristic assignments and state-of-the art phylogenetic comparative methods to estimate within- and across-habitat diversification patterns. Our analyses showed that Saxifragales diversified into multiple habitats from a forest-inhabiting ancestor and that this diversification is governed by relatively rare habitat shifts. Lineages are likely to stay within inferred ancestral ecological conditions. Adaptation to some habitat types (e.g. aquatic, desert) may be canalizing events that lineages do not escape. Although associations between increased diversification rates and shifts in habitat preferences are occasionally observed, extreme macroevolutionary rates are closely associated with specific habitats. Lineages occurring in shrubland, and especially tundra and rock cliffs, exhibit comparatively high diversification, whereas forest, grassland, desert and aquatic habitats are associated with low diversification. The likelihood of occupation of new habitats appears to be asymmetric. Shifts to aquatic and desert habitats may be canalizing events. Other habitats, such as tundra, might act as evolutionary sources, while forests provide the only habitat seemingly colonized easily by lineages originating elsewhere. However, habitat shifts are very rare, and any major environmental alteration is expected to have dramatic evolutionary consequences. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

  2. Habitat Specialization in Tropical Continental Shelf Demersal Fish Assemblages

    PubMed Central

    Fitzpatrick, Ben M.; Harvey, Euan S.; Heyward, Andrew J.; Twiggs, Emily J.; Colquhoun, Jamie

    2012-01-01

    The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1–10 m depth), down the fore reef slope to the reef base (10–30 m depth) then across the adjacent continental shelf (30–110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected

  3. Creating Habitat for the Yellow-Billed Cuckoo (Coccyzus americana)

    Treesearch

    Bertin W. Anderson; Stephen A. Laymon

    1989-01-01

    Yellow-billed Cuckoo numbers have decreased alarmingly in recent decades. This is associated with demise of their riparian habitats. Study of habitat along the lower Colorado River and along the South Fork Kern River led to the conclusion that they require dense habitats dominated by cottonwood (Populus fremontii) and willow (Salix...

  4. Rates of evolution in stress-related genes are associated with habitat preference in two Cardamine lineages

    PubMed Central

    2012-01-01

    pressure between the C. impatiens and C. resedifolia lineages. The within-species analyses also revealed evolutionary patterns associated with habitat preference of two Cardamine species. We conclude that the selective pressures associated with the habitats typical of C. resedifolia may have caused the rapid evolution of genes involved in cold response. PMID:22257588

  5. Habitat specialization through germination cueing: a comparative study of herbs from forests and open habitats.

    PubMed

    Ten Brink, Dirk-Jan; Hendriksma, Harmen Pieter; Bruun, Hans Henrik

    2013-02-01

    This study examined the adaptive association between seed germination ecology and specialization to either forest or open habitats across a range of evolutionary lineages of seed plants, in order to test the hypotheses that (1) species' specialization to open vs. shaded habitats is consistently accompanied by specialization in their regeneration niche; and (2) species are thereby adapted to utilize different windows of opportunity in time (season) and space (habitat). Seed germination response to temperature, light and stratification was tested for 17 congeneric pairs, each consisting of one forest species and one open-habitat species. A factorial design was used with temperature levels and diurnal temperature variation (10 °C constant, 15-5 °C fluctuating, 20 °C constant, 25-15 °C fluctuating), and two light levels (light and darkness) and a cold stratification treatment. The congeneric species pair design took phylogenetic dependence into account. Species from open habitats germinated better at high temperatures, whereas forest species performed equally well at low and high temperatures. Forest species tended to germinate only after a period of cold stratification that could break dormancy, while species from open habitats generally germinated without cold stratification. The empirically derived germination strategies correspond quite well with establishment opportunities for forest and open-habitat plant species in nature. Annual changes in temperature and light regime in temperate forest delimit windows of opportunity for germination and establishment. Germination strategies of forest plants are adaptations to utilize such narrow windows in time. Conversely, lack of fit between germination ecology and environment may explain why species of open habitats generally fail to establish in forests. Germination strategy should be considered an important mechanism for habitat specialization in temperate herbs to forest habitats. The findings strongly suggest that

  6. Unionid habitat and assemblage composition in coastal plain tributaries of the Flint River (Georgia)

    USGS Publications Warehouse

    Gagnon, P.; Michener, W.; Freeman, M.; Brim-Box, J.

    2006-01-01

    Effective conservation of mussels in streams of the lower Flint River basin, southwest Georgia, requires more rigorous understanding of mussel-habitat associations and factors shaping assemblage composition in stream reaches. We surveyed mussels and habitat conditions at 46 locations, and used regression, correlation and multivariate direct gradient analysis (Canonical Correspondence Analyses) to identify species-habitat relationships and characteristic species-assemblage types in Flint basin streams. Riparian wetland and catchment forest cover, average mid-channel depth, and drainage network position accounted for 49% of the variability in mussel species richness, 36% of the variability in unionid abundance, and 32% of the variability observed in Shannon-Wiener diversity across survey sites. Species were grouped into four assemblage types based on their habitat associations: large-river-riffle associates, slackwater associates, habitat generalists, and stream-run associates. Results are broadly concordant with anecdotal reports of mussel-habitat relationships and provide insight into the habitat conservation needs of mussels.

  7. Riparian and Associated Habitat Characteristics Related to Nutrient Concentrations and Biological Responses of Small Streams in Selected Agricultural Areas, United States, 2003-04

    USGS Publications Warehouse

    Zelt, Ronald B.; Munn, Mark D.

    2009-01-01

    Physical factors, including both in-stream and riparian habitat characteristics that limit biomass or otherwise regulate aquatic biological condition, have been identified by previous studies. However, linking the ecological significance of nutrient enrichment to habitat or landscape factors that could allow for improved management of streams has proved to be a challenge in many regions, including agricultural landscapes, where many ecological stressors are strong and the variability among watersheds typically is large. Riparian and associated habitat characteristics were sampled once during 2003-04 for an intensive ecological and nutrients study of small perennial streams in five contrasting agricultural landscapes across the United States to determine how biological communities and ecosystem processes respond to varying levels of nutrient enrichment. Nutrient concentrations were determined in stream water at two different sampling times per site and biological samples were collected once per site near the time of habitat characterization. Data for 141 sampling sites were compiled, representing five study areas, located in parts of the Delmarva Peninsula (Delaware and Maryland), Georgia, Indiana, Ohio, Nebraska, and Washington. This report examines the available data for riparian and associated habitat characteristics to address questions related to study-unit contrasts, spatial scale-related differences, multivariate correlation structure, and bivariate relations between selected habitat characteristics and either stream nutrient conditions or biological responses. Riparian and associated habitat characteristics were summarized and categorized into 22 groups of habitat variables, with 11 groups representing land-use and land-cover characteristics and 11 groups representing other riparian or in-stream habitat characteristics. Principal components analysis was used to identify a reduced set of habitat variables that describe most of the variability among the

  8. Effects of spatial habitat heterogeneity on habitat selection and annual fecundity for a migratory forest songbird

    USGS Publications Warehouse

    Cornell, K.L.; Donovan, T.M.

    2010-01-01

    Understanding how spatial habitat patterns influence abundance and dynamics of animal populations is a primary goal in landscape ecology. We used an information-theoretic approach to investigate the association between habitat patterns at multiple spatial scales and demographic patterns for black-throated blue warblers (Dendroica caerulescens) at 20 study sites in west-central Vermont, USA from 2002 to 2005. Sites were characterized by: (1) territory-scale shrub density, (2) patch-scale shrub density occurring within 25 ha of territories, and (3) landscape-scale habitat patterns occurring within 5 km radius extents of territories. We considered multiple population parameters including abundance, age ratios, and annual fecundity. Territory-scale shrub density was most important for determining abundance and age ratios, but landscape-scale habitat structure strongly influenced reproductive output. Sites with higher territory-scale shrub density had higher abundance, and were more likely to be occupied by older, more experienced individuals compared to sites with lower shrub density. However, annual fecundity was higher on sites located in contiguously forested landscapes where shrub density was lower than the fragmented sites. Further, effects of habitat pattern at one spatial scale depended on habitat conditions at different scales. For example, abundance increased with increasing territory-scale shrub density, but this effect was much stronger in fragmented landscapes than in contiguously forested landscapes. These results suggest that habitat pattern at different spatial scales affect demographic parameters in different ways, and that effects of habitat patterns at one spatial scale depends on habitat conditions at other scales. ?? Springer Science+Business Media B.V. 2009.

  9. The forest ecosystem of Southeast Alaska: 4. Wildlife habitats.

    Treesearch

    William R. Meehan

    1974-01-01

    The effects of logging and associated activities on the habitat of the major forest wildlife species in southeast Alaska are discussed and research results applicable to this region are summarized. Big game, furbearers, and non-game species are considered with respect to their habitat requirements and behavior. Recommendations are made for habitat management with...

  10. Lidar: shedding new light on habitat characterization and modeling.

    Treesearch

    Kerri T. Vierling; Lee A. Vierling; William A. Gould; Sebastian Martinuzzi; Rick M. Clawges

    2008-01-01

    Ecologists need data on animal–habitat associations in terrestrial and aquatic environments to design and implement effective conservation strategies. Habitat characteristics used in models typically incorporate (1) field data of limited spatial extent and/or (2) remote sensing data that do not characterize the vertical habitat structure. Remote sensing tools that...

  11. New England wildlife: habitat, natural history, and distribution

    Treesearch

    Richard M. DeGraaf; Deborah D. Rudis

    1986-01-01

    Describes natural history profiles of New England wildlife species and their associations with forested and nonforested habitats. Provides a database that will enable forest managers or wildlife biologists to describe the species or groups to be found in a given habitat.

  12. Deep-Water Coral Diversity and Habitat Associations: Differences among Northeast Atlantic Submarine Canyons

    NASA Astrophysics Data System (ADS)

    Shank, T. M.

    2016-02-01

    From 2012 to 2015, annual seafloor surveys using the towed camera TowCam were used to characterize benthic ecosystems and habitats to groundtruth recently developed habitat suitability models that predict deep-sea coral locations in northwest Atlantic canyons. Faunal distribution, abundance, and habitat data were obtained from more than 90 towed camera surveys in 21 canyons, specifically Tom's, Hendrickson, Veatch, Gilbert, Ryan, Powell, Munson, Accomac, Leonard, Washington, Wilmington, Lindenkohl, Clipper, Sharpshooter, Welker, Dogbody, Chebacco, Heel Tapper, File Bottom, Carteret, and Spencer Canyons, as well as unnamed minor canyons and inter-canyon areas. We also investigated additional canyons including Block, Alvin, Atlantis, Welker, Heezen, Phoenix, McMaster, Nantucket, and two minor canyons and two intercanyon areas through high-definition ROV image surveys from the NOAA CANEX 2013 and 2014 expeditions. Significant differences in species composition and distribution correlated with specific habitat types, depth, and individual canyons. High abundances and diversity of scleractinians, antipatharians, octocorals and sponges were highly correlated with habitat substrates, includingvertical canyon walls, margins, sediments, cobbles, boulders, and coral rubble habitat. Significant differences in species composition among canyons were observed across similar depths suggesting that many canyons may have their own biological and geological signature. Locating and defining the composition and distribution of vulnerable coral ecosystems in canyons in concert with validating predictive species distribution modeling has resulted in the regional management and conservation recommendations of these living resources and the largest proposed Marine Protected Area in North American waters.

  13. Nekton-habitat associations in Yaquina Bay, Oregon - March 2008

    EPA Science Inventory

    We conducted a 3-year field study to determine the relative nekton usage of 4 intertidal habitats (eelgrass [Zostera marina], mud shrimp [Upogebia pugettensis], ghost shrimp [Neotrypaea californiensis], and unvegetated sand) in Yaquina Bay, Oregon. Nekton samples were collected u...

  14. Habitat association of larval fish assemblages in the northern Persian Gulf.

    PubMed

    Rabbaniha, Mahnaz; Molinero, Juan Carlos; López-López, Lucia; Javidpour, Jamileh; Primo, Ana Ligia; Owfi, Feryadoon; Sommer, Ulrich

    2015-08-15

    We examined the habitat use of fish larvae in the northern Persian Gulf from July 2006 to June 2007. Correspondence Analysis showed significant differences between hydrological seasons in habitat use and structure of larval fish assemblages, while no differences were found regarding abundance among coralline and non-coralline habitats. The observed configuration resulted in part from seasonal reproductive patterns of dominant fish influencing the ratio pelagic:demersal spawned larvae. The ratio increased along with temperature and chlorophyll-a concentration, which likely fostered the reproduction of pelagic spawner fish. The close covariation with temperature throughout hydrographic seasons suggests a leading role of temperature in the seasonal structure of larvae assemblages. Our results provide new insights on fish larval ecology in a traditionally sub-sampled and highly exposed zone to anthropogenic pollution, the northern Persian Gulf, and highlight the potential role of Khark and Kharko Islands in conservation and fishery management in the area. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Habitat Suitability Index Models: Mink

    USGS Publications Warehouse

    Allen, Arthur W.

    1983-01-01

    The mink (Mustela vison) is a predatory, semiaquatic mammal that is generally associated with stream and river banks, lake shores, fresh and saltwater marshes, and marine shore habitats (Gerell 1970).  Mink are chiefly nocturnal and remain active throughout the year (Marshall 1936); Gerell 1969; Burgess 1978).  The species is adaptable in its use of habitat, modifying daily habits according to environmental conditions, particularly prey availability (Wise et al. 1981; Linn and Birds 1981; Birks and Linn 1982).  The species is tolerant of human activity and will inhabit suboptimum habitats as long as an adequate food source is available; however, mink will be more mobile and change home ranges more frequently under such conditions (Linn pers. comm.).

  16. Can Environmental Education Actions Change Public Attitudes? An Example Using the Pond Habitat and Associated Biodiversity

    PubMed Central

    Sousa, Eunice; Quintino, Victor; Palhas, Jael; Rodrigues, Ana Maria; Teixeira, José

    2016-01-01

    Ponds provide vital ecological services. They are biodiversity hotspots and important breading sites for rare and endangered species, including amphibians and dragonflies. Nevertheless, their number is decreasing due to habitat degradation caused by human activities. The “Ponds with Life” environmental education project was developed to raise public awareness and engagement in the study of ponds by promoting the direct contact between the public and nature, researchers and pedagogical hands-on exploration activities. A pre-post- project survey was set-up to assess the effects of the project on the environmental consciousness, knowledge and attitude changes towards ponds and the associated biodiversity of school students aged 15 to 18. The survey questions were based on Likert scales and their pre-post project comparisons used an innovative multivariate hypothesis testing approach. The results showed that the project improved the students’ knowledge and attitudes towards ponds and associated biodiversity, especially the amphibians. Ponds can be found or constructed in urban areas and despite small sized, they proved to be interesting model habitats and living laboratories to foster environmental education, by encompassing a high number of species and a fast ecological succession. PMID:27148879

  17. Can Environmental Education Actions Change Public Attitudes? An Example Using the Pond Habitat and Associated Biodiversity.

    PubMed

    Sousa, Eunice; Quintino, Victor; Palhas, Jael; Rodrigues, Ana Maria; Teixeira, José

    2016-01-01

    Ponds provide vital ecological services. They are biodiversity hotspots and important breading sites for rare and endangered species, including amphibians and dragonflies. Nevertheless, their number is decreasing due to habitat degradation caused by human activities. The "Ponds with Life" environmental education project was developed to raise public awareness and engagement in the study of ponds by promoting the direct contact between the public and nature, researchers and pedagogical hands-on exploration activities. A pre-post- project survey was set-up to assess the effects of the project on the environmental consciousness, knowledge and attitude changes towards ponds and the associated biodiversity of school students aged 15 to 18. The survey questions were based on Likert scales and their pre-post project comparisons used an innovative multivariate hypothesis testing approach. The results showed that the project improved the students' knowledge and attitudes towards ponds and associated biodiversity, especially the amphibians. Ponds can be found or constructed in urban areas and despite small sized, they proved to be interesting model habitats and living laboratories to foster environmental education, by encompassing a high number of species and a fast ecological succession.

  18. Habitat characteristics of larval mosquitoes in zoos of South Carolina, USA.

    PubMed

    Tuten, Holly C

    2011-06-01

    To investigate whether the unique assemblage of habitats in zoos could affect mosquito oviposition behavior and to provide zoos with suggestions for mosquito control, larvae were sampled and associated habitat variables were measured in 2 zoos in South Carolina, U.S.A. Fifty-nine sites were sampled from March 2008 to January 2009. A total of 1630 larvae representing 16 species was collected and identified. The dominant species was Aedes albopictus (46.0%), followed by Ae. triseriatus (23.6%), Culex restuans (12.4%), and Cx. pipiens complex (9.7%). Principal components and multiple logistic regression analyses showed that across both zoos the distribution of Ae. albopictus larvae was predicted by ambient and site temperature, precipitation, dissolved oxygen, and container habitats. The distribution of Ae. triseriatus larvae was predicted by natural containers and shade height < or =2 m. Overall larval mosquito presence (regardless of species) was predicted by ambient and site temperature, precipitation, dissolved oxygen, presence of natural habitats, and absence of aquatic vegetation. Additionally, C8 values of pairwise species associations indicated significant habitat-based relationships between Ae. albopictus and Ae. triseriatus, and Cx. pipiens complex and Cx. restuans. In general, species-habitat associations conformed to previously published studies. Recommendations to zoo personnel include elimination of artificial container habitats, reduction of shade sources < or =2 m over aquatic habitats, use of approved mosquito larvicides, and training in recognizing and mitigating larval mosquito habitats.

  19. Habitat degradation disrupts neophobia in juvenile coral reef fish.

    PubMed

    McCormick, Mark I; Chivers, Douglas P; Allan, Bridie J M; Ferrari, Maud C O

    2017-02-01

    Habitat degradation not only disrupts habitat-forming species, but alters the sensory landscape within which most species must balance behavioural activities against predation risk. Rapidly developing a cautious behavioural phenotype, a condition known as neophobia, is advantageous when entering a novel risky habitat. Many aquatic organisms rely on damage-released conspecific cues (i.e. alarm cues) as an indicator of impending danger and use them to assess general risk and develop neophobia. This study tested whether settlement-stage damselfish associated with degraded coral reef habitats were able to use alarm cues as an indicator of risk and, in turn, develop a neophobic response at the end of their larval phase. Our results indicate that fish in live coral habitats that were exposed to alarm cues developed neophobia, and, in situ, were found to be more cautious, more closely associated with their coral shelters and survived four-times better than non-neophobic control fish. In contrast, fish that settled onto degraded coral habitats did not exhibit neophobia and consequently suffered much greater mortality on the reef, regardless of their history of exposure to alarm cues. Our results show that habitat degradation alters the efficacy of alarm cues with phenotypic and survival consequences for newly settled recruits. © 2016 John Wiley & Sons Ltd.

  20. Habitat segregation of mosquito arbovirus vectors in south Florida.

    PubMed

    Rey, Jorge R; Nishimura, Naoya; Wagner, Billi; Braks, Marieta A H; O'Connell, Sheila M; Lounibos, L Philip

    2006-11-01

    Oviposition traps set in rural to urban environments in three south Florida counties were colonized predominantly by Culex quinquefasciatus Say (35.1%), Aedes albopictus (Skuse) (34.5%), Aedes aegypti (L.) (23.8%), and Culex nigripalpus Theobald (6.6%) during 1 yr of monthly sampling. Significant differences were detected among counties for abundances of Cx. quinquefasciatus and for percentage composition of that species and Ae. albopictus. Aerial images of habitats around each collection site were digitized, and coverages by each of 16 habitat variables were recorded. Abundances ofAe. aegypti were positively related to habitat variables associated with urbanization and negatively correlated to those reflecting rural characteristics. Multiple regression models of habitat selection explained similar proportions of variances in abundance of Ae. aegypti and Ae. albopictus, but signs of significant variables were opposite for these two species. No consistent trends of habitat associations were observed among counties for the two Culex spp. Co-occurrences of the four species in individual traps depended on container type (tub versus cup), and, for Aedes spp. with Culex spp., county. The results underscore the importance of scale in evaluating habitat selection and the utility of quantifiable habitat characteristics of intermediate scale to identify site characteristics favored by the arboviral vectors Ae. aegypti and Ae. albopictus.

  1. Altered juvenile fish communities associated with invasive Halophila stipulacea seagrass habitats in the U.S. Virgin Islands.

    PubMed

    Olinger, Lauren K; Heidmann, Sarah L; Durdall, Allie N; Howe, Colin; Ramseyer, Tanya; Thomas, Sara G; Lasseigne, Danielle N; Brown, Elizabeth J; Cassell, John S; Donihe, Michele M; Duffing Romero, Mareike D; Duke, Mara A; Green, Damon; Hillbrand, Paul; Wilson Grimes, Kristin R; Nemeth, Richard S; Smith, Tyler B; Brandt, Marilyn

    2017-01-01

    Caribbean seagrass habitats provide food and protection for reef-associated juvenile fish. The invasive seagrass Halophila stipulacea is rapidly altering these seascapes. Since its arrival in the Caribbean in 2002, H. stipulacea has colonized and displaced native seagrasses, but the function of this invasive seagrass as a juvenile fish habitat remains unknown. To compare diversity, community structure, and abundance of juvenile fish between H. stipulacea and native seagrass beds, fish traps were deployed in four nearshore bays around St. Thomas, U.S. Virgin Islands. Traps were deployed in Frenchman, Lindbergh, and Sprat Bays for 24 h intervals in patches of bare sand, patches of H. stipulacea and patches of the native Caribbean seagrasses Thalassia testudinum and Syringodium filiforme. Traps were then deployed in Brewers Bay for 12 h intervals in stands of H. stipulacea and S. filiforme. Relative and total abundances of juvenile fish, identified at least to family, were compared across treatment habitats for each trap deployment period. The catch from H. stipulacea, compared to native seagrasses, comprised a greater abundance of nocturnal carnivores Lutjanus synagris (family Lutjanidae) and Haemulon flavolineatum (family Haemulidae). Additionally, the herbivore species Sparisoma aurofrenatum (family Labridae) and Acanthurus bahianus (family Acanthuridae) and the diurnal carnivore species Pseudopeneus maculatus (family Mullidae) were relatively scarce in H. stipulacea. The catch from sand was much smaller, compared to vegetated habitats, and comprised only L. synagris, H. flavolineatum, and H. aurolineatum. These results provide evidence of reduced family diversity and altered juvenile fish assemblages in H. stipulacea, driven by an abundance of some nocturnal carnivores and scarcity of herbivores and diurnal carnivores. The findings from the present work underpin the need for further investigation and mitigation of this invasion, particularly where H. stipulacea is

  2. Altered juvenile fish communities associated with invasive Halophila stipulacea seagrass habitats in the U.S. Virgin Islands

    PubMed Central

    Brown, Elizabeth J.; Cassell, John S.; Donihe, Michele M.; Duffing Romero, Mareike D.; Duke, Mara A.; Green, Damon; Hillbrand, Paul; Wilson Grimes, Kristin R.; Nemeth, Richard S.; Smith, Tyler B.; Brandt, Marilyn

    2017-01-01

    Caribbean seagrass habitats provide food and protection for reef-associated juvenile fish. The invasive seagrass Halophila stipulacea is rapidly altering these seascapes. Since its arrival in the Caribbean in 2002, H. stipulacea has colonized and displaced native seagrasses, but the function of this invasive seagrass as a juvenile fish habitat remains unknown. To compare diversity, community structure, and abundance of juvenile fish between H. stipulacea and native seagrass beds, fish traps were deployed in four nearshore bays around St. Thomas, U.S. Virgin Islands. Traps were deployed in Frenchman, Lindbergh, and Sprat Bays for 24 h intervals in patches of bare sand, patches of H. stipulacea and patches of the native Caribbean seagrasses Thalassia testudinum and Syringodium filiforme. Traps were then deployed in Brewers Bay for 12 h intervals in stands of H. stipulacea and S. filiforme. Relative and total abundances of juvenile fish, identified at least to family, were compared across treatment habitats for each trap deployment period. The catch from H. stipulacea, compared to native seagrasses, comprised a greater abundance of nocturnal carnivores Lutjanus synagris (family Lutjanidae) and Haemulon flavolineatum (family Haemulidae). Additionally, the herbivore species Sparisoma aurofrenatum (family Labridae) and Acanthurus bahianus (family Acanthuridae) and the diurnal carnivore species Pseudopeneus maculatus (family Mullidae) were relatively scarce in H. stipulacea. The catch from sand was much smaller, compared to vegetated habitats, and comprised only L. synagris, H. flavolineatum, and H. aurolineatum. These results provide evidence of reduced family diversity and altered juvenile fish assemblages in H. stipulacea, driven by an abundance of some nocturnal carnivores and scarcity of herbivores and diurnal carnivores. The findings from the present work underpin the need for further investigation and mitigation of this invasion, particularly where H. stipulacea is

  3. Habitat split and the global decline of amphibians.

    PubMed

    Becker, Carlos Guilherme; Fonseca, Carlos Roberto; Haddad, Célio Fernando Baptista; Batista, Rômulo Fernandes; Prado, Paulo Inácio

    2007-12-14

    The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely "habitat split"-defined as human-induced disconnection between habitats used by different life history stages of a species-which forces forest-associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development (the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.

  4. Stratification of habitats for identifying habitat selection by Merriam's turkeys

    Treesearch

    Mark A. Rumble; Stanley H. Anderson

    1992-01-01

    Habitat selection patterns of Merriam’s Turkeys were compared in hierarchical analyses of three levels of habitat stratification. Habitat descriptions in first-level analyses were based on dominant species of vegetation. Habitat descriptions in second-level analyses were based on dominant species of vegetation and overstory canopy cover. Habitat descriptions in third-...

  5. Sensitivity analysis of physiological factors in space habitat design

    NASA Technical Reports Server (NTRS)

    Billingham, J.

    1982-01-01

    The costs incurred by design conservatism in space habitat design are discussed from a structural standpoint, and areas of physiological research into less than earth-normal conditions that offer the greatest potential decrease in habitat construction and operating costs are studied. The established range of human tolerance limits is defined for those physiological conditions which directly affect habitat structural design. These entire ranges or portions thereof are set as habitat design constraints as a function of habitat population and degree of ecological closure. Calculations are performed to determine the structural weight and cost associated with each discrete population size and its selected environmental conditions, on the basis of habitable volume equivalence for four basic habitat configurations: sphere, cylinder with hemispherical ends, torus, and crystal palace.

  6. Habitat Evaluation Procedures Report; Carl Property - Yakama Nation.

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

    Ashley, Paul; Muse, Anthony

    A baseline habitat evaluation procedures (HEP) analysis was conducted on the Carl property (160 acres) in June 2007 to determine the number of habitat units to credit Bonneville Power Administration (BPA) for providing funds to acquire the property as partial mitigation for habitat losses associated with construction of McNary Dam. HEP surveys also helped assess the general ecological condition of the property. The Carl property appeared damaged from livestock grazing and exhibited a high percentage of invasive forbs. Exotic grasses, while present, did not comprise a large percentage of the available cover in most areas. Cover types were primarily grassland/shrubsteppemore » with a limited emergent vegetation component. Baseline HEP surveys generated 356.11 HUs or 2.2 HUs per acre. Habitat units were associated with the following HEP models: California quail (47.69 HUs), western meadowlark (114.78 HUs), mallard (131.93 HUs), Canada goose (60.34 HUs), and mink (1.38 HUs).« less

  7. Sparse ice: Geophysical, biological and Indigenous knowledge perspectives on a habitat for ice-associated fauna

    NASA Astrophysics Data System (ADS)

    Lee, O. A.; Eicken, H.; Weyapuk, W., Jr.; Adams, B.; Mohoney, A. R.

    2015-12-01

    The significance of highly dispersed, remnant Arctic sea ice as a platform for marine mammals and indigenous hunters in spring and summer may have increased disproportionately with changes in the ice cover. As dispersed remnant ice becomes more common in the future it will be increasingly important to understand its ecological role for upper trophic levels such as marine mammals and its role for supporting primary productivity of ice-associated algae. Potential sparse ice habitat at sea ice concentrations below 15% is difficult to detect using remote sensing data alone. A combination of high resolution satellite imagery (including Synthetic Aperture Radar), data from the Barrow sea ice radar, and local observations from indigenous sea ice experts was used to detect sparse sea ice in the Alaska Arctic. Traditional knowledge on sea ice use by marine mammals was used to delimit the scales where sparse ice could still be used as habitat for seals and walrus. Potential sparse ice habitat was quantified with respect to overall spatial extent, size of ice floes, and density of floes. Sparse ice persistence offshore did not prevent the occurrence of large coastal walrus haul outs, but the lack of sparse ice and early sea ice retreat coincided with local observations of ringed seal pup mortality. Observations from indigenous hunters will continue to be an important source of information for validating remote sensing detections of sparse ice, and improving understanding of marine mammal adaptations to sea ice change.

  8. Landscape genetics in the subterranean rodent Ctenomys "chasiquensis" associated with highly disturbed habitats from the southeastern Pampas region, Argentina.

    PubMed

    Mora, Matías Sebastián; Mapelli, Fernando J; López, Aldana; Gómez Fernández, María Jimena; Mirol, Patricia M; Kittlein, Marcelo J

    2017-12-01

    Studies of genetic differentiation in fragmented environments help us to identify those landscape features that most affect gene flow and dispersal patterns. Particularly, the assessment of the relative significance of intrinsic biological and environmental factors affecting the genetic structure of populations becomes crucial. In this work, we assess the current dispersal patterns and population structure of Ctenomys "chasiquensis", a vulnerable and endemic subterranean rodent distributed on a small area in Central Argentina, using 9 polymorphic microsatellite loci. We use landscape genetics approaches to assess the relationship between genetic connectivity among populations and environmental attributes. Our analyses show that populations of C. "chasiquensis" are moderately to highly structured at a regional level. This pattern is most likely the outcome of substantial gene flow on the more homogeneous sand dune habitat of the Northwest of its distributional range, in conjunction with an important degree of isolation of eastern and southwestern populations, where the optimal habitat is surrounded by a highly fragmented landscape. Landscape genetics analysis suggests that habitat quality and longitude were the environmental factors most strongly associated with genetic differentiation/uniqueness of populations. In conclusion, our results indicate an important genetic structure in this species, even at a small spatial scale, suggesting that contemporary habitat fragmentation increases population differentiation.

  9. Specializing on vulnerable habitat: Acropora selectivity among damselfish recruits and the risk of bleaching-induced habitat loss

    NASA Astrophysics Data System (ADS)

    Bonin, M. C.

    2012-03-01

    Coral reef habitats are increasingly being degraded and destroyed by a range of disturbances, most notably climate-induced coral bleaching. Habitat specialists, particularly those associated with susceptible coral species, are clearly among the most vulnerable to population decline or extinction. However, the degree of specialization on coral microhabitats is still unclear for one of the most ubiquitous, abundant and well studied of coral reef fish families—the damselfishes (Pomacentridae). Using high taxonomic resolution surveys of microhabitat use and availability, this study provides the first species-level description of patterns of Acropora selectivity among recruits of 10 damselfish species in order to determine their vulnerability to habitat degradation. In addition, surveys of the bleaching susceptibility of 16 branching coral species revealed which preferred recruitment microhabitats are at highest risk of decline as a result of chronic coral bleaching. Four species (i.e., Chrysiptera parasema, Pomacentrus moluccensis, Dascyllus melanurus and Chromis retrofasciata) were identified as highly vulnerable because they used only branching hard corals as recruitment habitat and primarily associated with only 2-4 coral species. The bleaching surveys revealed that five species of Acropora were highly susceptible to bleaching, with more than 50% of colonies either severely bleached or already dead. These highly susceptible corals included two of the preferred microhabitats of the specialist C. parasema and represented a significant proportion of its total recruitment microhabitat. In contrast, highly susceptible corals were rarely used by another specialist, P. moluccensis, suggesting that this species faces a lower risk of bleaching-induced habitat loss compared to C. parasema. As degradation to coral reef habitats continues, specialists will increasingly be forced to use alternative recruitment microhabitats, and this is likely to reduce population

  10. Earth is a Marine Habitat. Habitat Conservation Program.

    ERIC Educational Resources Information Center

    National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

    This brochure is intended to educate the public about the need to conserve and preserve the earth's environment (man's habitat). It contains an introduction to the ocean world and threats to coastal habitat. Photos and narrative revolve around the theme "Earth is a Marine Habitat." Sections include: "The Web of…

  11. Using landslide risk analysis to protect fish habitat

    Treesearch

    R. M. Rice

    1986-01-01

    The protection of anadromous fish habitat is an important water quslity concern in the Pacific Northwest. Sediment from logging-related debris avalanches can cause habitat degradation. Research on conditions associated with the sites where debris avalanches originate has resulted in a risk assessment methodology based on linear discriminant analysis. The probability...

  12. Species associations and habitat influence the range-wide distribution of breeding Canada Geese (Branta canadensis interior) on Western Hudson Bay

    USGS Publications Warehouse

    Reiter, Matthew E.; Andersen, David E.; Raedeke, Andrew H.; Humburg, Dale D.

    2017-01-01

    Inter- and intra-specific interactions are potentially important factors influencing the distribution of populations. Aerial survey data, collected during range-wide breeding population surveys for Eastern Prairie Population (EPP) Canada Geese (Branta canadensis interior), 1987–2008, were evaluated to assess factors influencing their nesting distribution. Specifically, associations between nesting Lesser Snow Geese (Chen caerulescens caerulescens) and EPP Canada Geese were quantified; and changes in the spatial distribution of EPP Canada Geese were identified. Mixed-effects Poisson regression models of EPP Canada Goose nest counts were evaluated within a cross-validation framework. The total count of EPP Canada Goose nests varied moderately among years between 1987 and 2008 with no long-term trend; however, the total count of nesting Lesser Snow Geese generally increased. Three models containing factors related to previous EPP Canada Goose nest density (representing recruitment), distance to Hudson Bay (representing brood-habitat), nesting habitat type, and Lesser Snow Goose nest density (inter-specific associations) were the most accurate, improving prediction accuracy by 45% when compared to intercept-only models. EPP Canada Goose nest density varied by habitat type, was negatively associated with distance to coastal brood-rearing areas, and suggested density-dependent intra-specific effects on recruitment. However, a non-linear relationship between Lesser Snow and EPP Canada Goose nest density suggests that as nesting Lesser Snow Geese increase, EPP Canada Geese locally decline and subsequently the spatial distribution of EPP Canada Geese on western Hudson Bay has changed.

  13. Aquatic habitat modifications in La Plata River basin, Patagonia and associated marine areas.

    PubMed

    Mugetti, Ana Cristina; Calcagno, Alberto Tomás; Brieva, Carlos Alberto; Giangiobbe, María Silvia; Pagani, Andrea; Gonzalez, Silvia

    2004-02-01

    This paper describes the environmental characteristics and situation of aquatic habitats and communities in southern continental and maritime areas of southeastern South America (Patagonian Shelf GIWA Subregion), resulting from an overall assessment carried out within the framework of a GIWA project, mostly on the basis of publicly available data. The main focus of the analysis was on the current situation of transboundary water resources and anthropogenic impacts. In the inland waters, habitat and community modifications result, principally, from dams and reservoirs built in the main watercourses for hydroelectric power generation and other uses. The transformation of lotic environments into lentic ones have affected habitats and altered biotic communities. In the La Plata River basin, invasive exotic species have displaced native ones. Habitats in the ocean have been degraded, as their biodiversity becomes affected by overfishing and pollution. This article includes a discussion on the causal chain and the policy options elaborated for the Coastal Ecosystem of Buenos Aires province and the Argentinean-Uruguayan Common Fishing Zone, where fishing resources are shared by both countries.

  14. Defining habitat covariates in camera-trap based occupancy studies

    PubMed Central

    Niedballa, Jürgen; Sollmann, Rahel; Mohamed, Azlan bin; Bender, Johannes; Wilting, Andreas

    2015-01-01

    In species-habitat association studies, both the type and spatial scale of habitat covariates need to match the ecology of the focal species. We assessed the potential of high-resolution satellite imagery for generating habitat covariates using camera-trapping data from Sabah, Malaysian Borneo, within an occupancy framework. We tested the predictive power of covariates generated from satellite imagery at different resolutions and extents (focal patch sizes, 10–500 m around sample points) on estimates of occupancy patterns of six small to medium sized mammal species/species groups. High-resolution land cover information had considerably more model support for small, patchily distributed habitat features, whereas it had no advantage for large, homogeneous habitat features. A comparison of different focal patch sizes including remote sensing data and an in-situ measure showed that patches with a 50-m radius had most support for the target species. Thus, high-resolution satellite imagery proved to be particularly useful in heterogeneous landscapes, and can be used as a surrogate for certain in-situ measures, reducing field effort in logistically challenging environments. Additionally, remote sensed data provide more flexibility in defining appropriate spatial scales, which we show to impact estimates of wildlife-habitat associations. PMID:26596779

  15. Selecting habitat management strategies on refuges

    USGS Publications Warehouse

    Schroeder, Richard L.; King, Wayne J.; Cornely, John E.

    1998-01-01

    This report is a joint effort of the Biological Resources Division, U.S. Geological Survey and the U.S. Fish and Wildlife Service (FWS) to provide National Wildlife Refuge (NWR) managers guidance on the selection and evaluation of habitat management strategies to meet stated objectives. The FWS recently completed a handbook on writing refuge management goals and objectives (U.S. Fish and Wildlife Service 1996a). the National Wildlife Refuge System Improvement Act of 1997 requires that National Wildlife Refuge System (NWRS) lands be managed according to approved Comprehensive Conservation Plans to guide management decisions and devise strategies for achieving refuge unit purposes and meeting the NWRS mission. It is expected that over the next several years most refuges will develop new or revised refuge goals and objectives for directing their habitat management strategies. This paper outlines the steps we recommend in selecting and evaluating habitat management strategies to meet specific refuge habitat objectives. We selected two examples to illustrate the process. Although each refuge is unique and will require specific information and solutions, these two examples can be used as guidance when selecting and evaluating habitat management strategies for other refuge resources: Example 1. Management of floodplain woods habitat for forest interior birds. The biological recourse of concern is the quality and quantity of floodplain woods habitat for eastern forest interior birds in the Cypress Creek NWR (U.S. Fish and Wildlife Service 1996b). Example 2. Management of habitat for biodiversity: Historical landscape proportions. The biological resource of concern is the change in diversity associated with man-induced changes in the distribution and abundance of habitat types at the Minnesota Valley NWR (U.S. Fish and Wildlife Service 1996c).

  16. Encroachment of oriental bittersweet into Pitcher’s thistle habitat

    USGS Publications Warehouse

    Leicht-Young, Stacey A.; Pavlovic, Noel B.

    2012-01-01

    Common invasive species and rare endemic species can grow and interact at the ecotone between forested and non-forested dune habitats. To investigate these interactions, a comparison of the proximity and community associates of a sympatric invasive (Celastrus orbiculatus; oriental bittersweet) and native (C. scandens; American bittersweet) liana species to federally threatened Cirsium pitcheri (Pitcher's thistle) in the dunes habitats of Lake Michigan was conducted. Overall, the density of the invasive liana species was significantly greater in proximity to C. pitcheri than the native species. On the basis of composition, the three focal species occurred in both foredune and blowout habitats. The plant communities associated with the three focal species overlapped in ordination space, but there were significant differences in composition. The ability of C. orbiculatus to rapidly grow and change the ecological dynamics of invasion sites adds an additional threat to the successional habitats of C. pitcheri.

  17. Mapping cold-water coral habitats at different scales within the Northern Ionian Sea (Central Mediterranean): an assessment of coral coverage and associated vulnerability.

    PubMed

    Savini, Alessandra; Vertino, Agostina; Marchese, Fabio; Beuck, Lydia; Freiwald, André

    2014-01-01

    In this study, we mapped the distribution of Cold-Water Coral (CWC) habitats on the northern Ionian Margin (Mediterranean Sea), with an emphasis on assessing coral coverage at various spatial scales over an area of 2,000 km(2) between 120 and 1,400 m of water depth. Our work made use of a set of data obtained from ship-based research surveys. Multi-scale seafloor mapping data, video inspections, and previous results from sediment samples were integrated and analyzed using Geographic Information System (GIS)-based tools. Results obtained from the application of spatial and textural analytical techniques to acoustic meso-scale maps (i.e. a Digital Terrain Model (DTM) of the seafloor at a 40 m grid cell size and associated terrain parameters) and large-scale maps (i.e. Side-Scan Sonar (SSS) mosaics of 1 m in resolution ground-truthed using underwater video observations) were integrated and revealed that, at the meso-scale level, the main morphological pattern (i.e. the aggregation of mound-like features) associated with CWC habitat occurrences was widespread over a total area of 600 km(2). Single coral mounds were isolated from the DTM and represented the geomorphic proxies used to model coral distributions within the investigated area. Coral mounds spanned a total area of 68 km(2) where different coral facies (characterized using video analyses and mapped on SSS mosaics) represent the dominant macro-habitat. We also mapped and classified anthropogenic threats that were identifiable within the examined videos, and, here, discuss their relationship to the mapped distribution of coral habitats and mounds. The combined results (from multi-scale habitat mapping and observations of the distribution of anthropogenic threats) provide the first quantitative assessment of CWC coverage for a Mediterranean province and document the relevant role of seafloor geomorphology in influencing habitat vulnerability to different types of human pressures.

  18. Wildlife guilds in Arizona desert habitats

    USGS Publications Warehouse

    Short, Henry L.

    1983-01-01

    This report summarizes information produced from Interagency Agreement No. AA-851-IA1-27 between the Bureau of Land Management (BLM), USDI, and the Fish and Wildlife Service (FWS), USDI. The contract was instrumental in the final development of wildlife guilds for the Hualapai-Aquarius planning area of the BLM in westcentral Arizona, reported herein. The Arizona study area was selected for the application of the guilding technology because a thorough assessment of the floral and faunal resources had recently occurred in conjunction with the development of a grazing Environmental Impact Statement (EIS). Thus, the association of wildlife species with habitat type was well known, which aided in the compilation of the data base necessary for the development of guilds. Some data were also available that described the vegetative structure of habitats. This was useful in the development of a model that evaluated the quality of habitat on the basis of the diversity of cover in those habitats (Short 1982).

  19. Surface Habitat Systems

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.

    2009-01-01

    The Surface Habitat Systems (SHS) Focused Investment Group (FIG) is part of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) effort to provide a focused direction and funding to the various projects that are working on human surface habitat designs and technologies for the planetary exploration missions. The overall SHS-FIG effort focuses on directing and guiding those projects that: 1) develop and demonstrate new surface habitat system concepts, innovations, and technologies to support human exploration missions, 2) improve environmental systems that interact with human habitats, 3) handle and emplace human surface habitats, and 4) focus on supporting humans living and working in habitats on planetary surfaces. The activity areas of the SHS FIG described herein are focused on the surface habitat project near-term objectives as described in this document. The SHS-FIG effort focuses on mitigating surface habitat risks (as identified by the Lunar Surface Systems Project Office (LSSPO) Surface Habitat Element Team; and concentrates on developing surface habitat technologies as identified in the FY08 gap analysis. The surface habitat gap assessment will be updated annually as the surface architecture and surface habitat definition continues to mature. These technologies are mapped to the SHS-FIG Strategic Development Roadmap. The Roadmap will bring to light the areas where additional innovative efforts are needed to support the development of habitat concepts and designs and the development of new technologies to support of the LSSPO Habitation Element development plan. Three specific areas of development that address Lunar Architecture Team (LAT)-2 and Constellation Architecture Team (CxAT) Lunar habitat design issues or risks will be focused on by the SHS-FIG. The SHS-FIG will establish four areas of development that will help the projects prepare in their planning for surface habitat systems development. Those development areas are

  20. Riverine habitat dynamics

    USGS Publications Warehouse

    Jacobson, R.B.

    2013-01-01

    The physical habitat template is a fundamental influence on riverine ecosystem structure and function. Habitat dynamics refers to the variation in habitat through space and time as the result of varying discharge and varying geomorphology. Habitat dynamics can be assessed at spatial scales ranging from the grain (the smallest resolution at which an organism relates to its environment) to the extent (the broadest resolution inclusive of all space occupied during its life cycle). In addition to a potentially broad range of spatial scales, assessments of habitat dynamics may include dynamics of both occupied and nonoccupied habitat patches because of process interactions among patches. Temporal aspects of riverine habitat dynamics can be categorized into hydrodynamics and morphodynamics. Hydrodynamics refers to habitat variation that results from changes in discharge in the absence of significant change of channel morphology and at generally low sediment-transport rates. Hydrodynamic assessments are useful in cases of relatively high flow exceedance (percent of time a flow is equaled or exceeded) or high critical shear stress, conditions that are applicable in many studies of instream flows. Morphodynamics refers to habitat variation resulting from changes to substrate conditions or channel/floodplain morphology. Morphodynamic assessments are necessary when channel and floodplain boundary conditions have been significantly changed, generally by relatively rare flood events or in rivers with low critical shear stress. Morphodynamic habitat variation can be particularly important as disturbance mechanisms that mediate population growth or for providing conditions needed for reproduction, such as channel-migration events that erode cutbanks and provide new pointbar surfaces for germination of riparian trees. Understanding of habitat dynamics is increasing in importance as societal goals shift toward restoration of riverine ecosystems. Effective investment in restoration

  1. Invasion by nonnative brook trout in Panther Creek, Idaho: Roles of local habitat quality, biotic resistance, and connectivity to source habitats

    USGS Publications Warehouse

    Benjamin, Joseph R.; Dunham, Jason B.; Dare, M.R.

    2007-01-01

    Theoretical models and empirical evidence suggest that the invasion of nonnative species in freshwaters is facilitated through the interaction of three factors: habitat quality, biotic resistance, and connectivity. We measured variables that represented each factor to determine which were associated with the occurrence of nonnative brook trout Salvelinus fontinalis in Panther Creek, a tributary to the Salmon River, Idaho. Habitat variables included measures of summer and winter temperature, instream cover, and channel size. The abundance of native rainbow trout Oncorhynchus mykiss within sampled sites was used as a measure of biotic resistance. We also considered the connectivity of sample sites to unconfined valley bottoms, which were considered habitats that may serve as sources for the spread of established populations of brook trout. We analyzed the occurrence of small (<150‐mm [fork length]) and large (≥150‐mm) brook trout separately, assuming that the former represents an established invasion while accounting for the higher potential mobility of the latter. The occurrence of small brook trout was strongly associated with the proximity of sites to large, unconstrained valley bottoms, providing evidence that such habitats may serve as sources for the spread of brook trout invasion. Within sites, winter degree‐days and maximum summer temperature were positively associated with the occurrence of small brook trout. The occurrence of large brook trout was not related to any of the variables considered, perhaps due to the difficulty of linking site‐specific habitat factors to larger and more mobile individuals. The abundance of rainbow trout was not conclusively associated with the occurrence of either small or large brook trout, providing little support for the role of biotic resistance. Overall, our results suggest that source connectivity and local habitat characteristics, but not biotic resistance, influence the establishment and spread of

  2. Sonoran pronghorn habitat use on landscapes disturbed by military activities

    USGS Publications Warehouse

    Krausman, P.R.; Harris, L.K.; Haas, S.K.; Koenen, Kiana K. G.; Devers, P.; Bunting, D.; Barb, M.

    2005-01-01

    The Sonoran pronghorn (Antilocapra americana sonoriensis) population in the United States declined to ???33 animals in January 2003. Low population numbers and unstable recruitment are concerns for biologists managing this subspecies. We examined habitat use by pronghorn from 1999 to 2002 on a portion of the Barry M. Goldwater Range (BMGR) used for military exercises. We overlaid locations of pronghorn (n= 1,203) on 377 1-km2 blocks within the North (NTAC) and South Tactical Ranges (STAC), BMGR; we classified vegetation associations and disturbance status (e.g., airfields, targets, roads) for each block. Locations of pronghorn were distributed in proportion to vegetation associations on NTAC and STAC. Sightings of pronghorns were biased toward disturbed blocks, with 73% of locations of pronghorn occurring in proximity to mock airfields, high-explosive hills (e.g., targets for live high-explosive bombs and rockets), other targets, and roads. Disturbed landscapes on the BMGR may attract Sonoran pronghorn by creating favorable forage. Habitat manipulations simulating the effects of military disturbances on the landscape (e.g., improved forage) may improve remaining Sonoran pronghorn habitat. Antilocapra americana sonoriensis, Barry M. Goldwater Air Force Range, disturbed habitat, habitat availability, habitat use, military activity, Sonoran pronghorn.

  3. Habitat selection and management of the Hawaiian crow

    USGS Publications Warehouse

    Giffen, J.G.; Scott, J.M.; Mountainspring, S.

    1987-01-01

    The abundance and range of the Hawaiian crow, or alala, (Corvus hawaiiensis) have decreased drastically since the 1890's. Fewer than 10 breeding pairs remained in the wild in 1985. A sample of 82 nests during 1970-82 were used to determine habitat associations. Two hundred firty-nine alala observations were used to estimate densities occurring in different vegetation types in 1978. Compared to available habitat, more nests and higher bird densities during the breeding season occurred in areas where: (1) canopy cover was > 60%; (2) koa (Acacia koa) and ohia (Metrosideros polymorpha) were dominant species in the crown layer; (3) native plants constituted > 75% of the understory cover; and (4) the elevation was 1,100-1,500 m. Compared to breeding habitat, nonbreeding habitat tended to lie at lower elevations and in wetter forests having the crown layer dominated by ohia but lacking koa. Habitat loss is a major factor underlying the decline of this species although predation on fledgings, avian disease, and shooting also have reduced the population. Remaining key habitat areas have little or no legal protection through zoning and land ownership. Preserves should be established to encompass the location of existing pairs and to assure the provision of optimum breeding habitat and suitable nonbreeding habitat.

  4. Stomach nematodes (Mastophorus muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) habitat at Palmyra Atoll.

    PubMed

    Lafferty, Kevin D; Hathaway, Stacie A; Wegmann, Alex S; Shipley, Frank S; Backlin, Adam R; Helm, Joel; Fisher, Robert N

    2010-02-01

    Black rats ( Rattus rattus ) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59%) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll.

  5. Comparative habitat ecology of Texas and masked bobwhites

    USGS Publications Warehouse

    Guthery, F.S.; King, N.M.; Nolte, K.R.; Kuvlesky, W.P.; DeStefano, S.; Gall, S.A.; Silvy, N.J.

    2000-01-01

    The habitat ecology of masked bobwhites (Colinus virginianus ridgwayi) is poorly understood, which hampers recovery efforts for this endangered bird. During 1994-96, we analyzed the habitat ecology of masked bobwhites in Sonora, Mexico, and Arizona, and compared these findings with the habitat ecology of Texas bobwhites (C. v. texanus) in southern Texas. Mean values for the quantity of low screening cover (<50 cm aboveground), operative temperature (??C), and exposure to aerial predators were relatively constant across regions (CV <14.2%), indicating these variables are important in adaptive habitat-use decisions by bobwhites. Bobwhites exhibited preference in all regions for higher canopy coverage of woody vegetation, lower exposure to aerial predators, and lower operative temperatures in comparison with randomly available conditions. The major habitat deficiencies for masked bobwhites were lack of woody and herbaceous cover, which led to high exposure to aerial predators in Sonora and Arizona. High operative temperatures at quail level were associated with the loss of ???24% of potential habitat space-time in Texas, Sonora, and Arizona. Management to improve habitat for masked bobwhites includes any practice that increases canopy coverage of woody vegetation, and height and coverage of herbaceous vegetation.

  6. Habitat-related specialization of lateral-line system morphology in a habitat-generalist and a habitat-specialist New Zealand eleotrid.

    PubMed

    Vanderpham, J P; Nakagawa, S; Senior, A M; Closs, G P

    2016-04-01

    An investigation of intraspecific habitat-related patterns of variation in oculoscapular lateral-line superficial neuromasts (SN) identified a decrease in the ratio of total SNs to pores, and a trend towards decreased asymmetry in SNs in the habitat-generalist common bully Gobiomorphus cotidianus from fluvial habitats compared to lacustrine habitats, suggesting habitat-related phenotypic variability. A greater ratio of pores to SNs, as well as less variation in the total number and asymmetry of SNs observed in the fluvial habitat-specialist redfin bully Gobiomorphus huttoni may provide further evidence of variations in the oculoscapular lateral-line morphology of fluvial habitat G. cotidianus individuals serving as adaptations to more turbulent environments. © 2016 The Fisheries Society of the British Isles.

  7. Evolutionary consequences of habitat loss for Pacific anadromous salmonids

    PubMed Central

    McClure, Michelle M; Carlson, Stephanie M; Beechie, Timothy J; Pess, George R; Jorgensen, Jeffrey C; Sogard, Susan M; Sultan, Sonia E; Holzer, Damon M; Travis, Joseph; Sanderson, Beth L; Power, Mary E; Carmichael, Richard W

    2008-01-01

    Large portions of anadromous salmonid habitat in the western United States has been lost because of dams and other blockages. This loss has the potential to affect salmonid evolution through natural selection if the loss is biased, affecting certain types of habitat differentially, and if phenotypic traits correlated with those habitat types are heritable. Habitat loss can also affect salmonid evolution indirectly, by reducing genetic variation and changing its distribution within and among populations. In this paper, we compare the characteristics of lost habitats with currently accessible habitats and review the heritability of traits which show correlations with habitat/environmental gradients. We find that although there is some regional variation, inaccessible habitats tend to be higher in elevation, wetter and both warmer in the summer and colder in the winter than habitats currently available to anadromous salmonids. We present several case studies that demonstrate either a change in phenotypic or life history expression or an apparent reduction in genetic variation associated with habitat blockages. These results suggest that loss of habitat will alter evolutionary trajectories in salmonid populations and Evolutionarily Significant Units. Changes in both selective regime and standing genetic diversity might affect the ability of these taxa to respond to subsequent environmental perturbations. Both natural and anthropogenic and should be considered seriously in developing management and conservation strategies. PMID:25567633

  8. An approach of habitat degradation assessment for characterization on coastal habitat conservation tendency.

    PubMed

    Zhou, Xi-Yin; Lei, Kun; Meng, Wei

    2017-09-01

    Coastal zones are population and economy highly intensity regions all over the world, and coastal habitat supports the sustainable development of human society. The accurate assessment of coastal habitat degradation is the essential prerequisite for coastal zone protection. In this study, an integrated framework of coastal habitat degradation assessment including landuse classification, habitat classifying and zoning, evaluation criterion of coastal habitat degradation and coastal habitat degradation index has been established for better regional coastal habitat assessment. Through establishment of detailed three-class landuse classification, the fine landscape change is revealed, the evaluation criterion of coastal habitat degradation through internal comparison based on the results of habitat classifying and zoning could indicate the levels of habitat degradation and distinguish the intensity of human disturbances in different habitat subareas under the same habitat classification. Finally, the results of coastal habitat degradation assessment could be achieved through coastal habitat degradation index (CHI). A case study of the framework is carried out in the Circum-Bohai-Sea-Coast, China, and the main results show the following: (1) The accuracy of all land use classes are above 90%, which indicates a satisfactory accuracy for the classification map. (2) The Circum-Bohai-Sea-Coast is divided into 3 kinds of habitats and 5 subareas. (3) In the five subareas of the Circum-Bohai-Sea-Coast, the levels of coastal habitat degradation own significant difference. The whole Circum-Bohai-Sea-Coast generally is in a worse state according to area weighting of each habitat subarea. This assessment framework of coastal habitat degradation would characterize the landuse change trend, realize better coastal habitat degradation assessment, reveal the habitat conservation tendency and distinguish intensity of human disturbances. Furthermore, it would support for accurate coastal

  9. 77 FR 41147 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-12

    ... segments and associated flycatcher habitat are anticipated to support the strategy, rationale, and science... strategy, rationale, and science of flycatcher conservation in order to meet territory and habitat-related... costs associated with monitoring and education activities, fencing, habitat restoration and creation...

  10. Molecular typing of Escherichia coli strains associated with threatened sea ducks and near-shore marine habitats of south-west Alaska

    USGS Publications Warehouse

    Hollmén, Tuula E.; DebRoy, Chitrita; Flint, Paul L.; Safine, David E.; Schamber, Jason L.; Riddle, Ann E.; Trust, Kimberly A.

    2011-01-01

    In Alaska, sea ducks winter in coastal habitats at remote, non-industrialized areas, as well as in proximity to human communities and industrial activity. We evaluated prevalence and characteristics of Escherichia coli strains in faecal samples of Steller's eiders (Polysticta stelleri; n = 122) and harlequin ducks (Histrionicus histrionicus; n = 21) at an industrialized site and Steller's eiders (n = 48) at a reference site, and compared these strains with those isolated from water samples from near-shore habitats of ducks. The overall prevalence of E. coli was 16% and 67% in Steller's eiders and harlequin ducks, respectively, at the industrialized study site, and 2% in Steller's eiders at the reference site. Based on O and H antigen subtyping and genetic characterization by enterobacterial repetitive intergenic consensus polymerase chain reaction and pulsed-field gel electrophoresis, we found evidence of avian pathogenic E. coli (APEC) strains associated with both species and detected E. coli strains carrying virulence genes associated with mammals in harlequin ducks. Steller's eiders that carried APEC had lower serum total protein and albumin concentrations, providing further evidence of pathogenicity. The genetic profile of two E. coli strains from water matched an isolate from a Steller's eider providing evidence of transmission between near-shore habitats and birds.

  11. Molecular typing of Escherichia coli strains associated with threatened sea ducks and near-shore marine habitats of south-west Alaska.

    PubMed

    Hollmén, Tuula E; Debroy, Chitrita; Flint, Paul L; Safine, David E; Schamber, Jason L; Riddle, Ann E; Trust, Kimberly A

    2011-04-01

    In Alaska, sea ducks winter in coastal habitats at remote, non-industrialized areas, as well as in proximity to human communities and industrial activity. We evaluated prevalence and characteristics of Escherichia coli strains in faecal samples of Steller's eiders (Polysticta stelleri; n = 122) and harlequin ducks (Histrionicus histrionicus; n = 21) at an industrialized site and Steller's eiders (n = 48) at a reference site, and compared these strains with those isolated from water samples from near-shore habitats of ducks. The overall prevalence of E. coli was 16% and 67% in Steller's eiders and harlequin ducks, respectively, at the industrialized study site, and 2% in Steller's eiders at the reference site. Based on O and H antigen subtyping and genetic characterization by enterobacterial repetitive intergenic consensus polymerase chain reaction and pulsed-field gel electrophoresis, we found evidence of avian pathogenic E. coli (APEC) strains associated with both species and detected E. coli strains carrying virulence genes associated with mammals in harlequin ducks. Steller's eiders that carried APEC had lower serum total protein and albumin concentrations, providing further evidence of pathogenicity. The genetic profile of two E. coli strains from water matched an isolate from a Steller's eider providing evidence of transmission between near-shore habitats and birds. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  12. Ecomorphology and phylogenetic risk: Implications for habitat reconstruction using fossil bovids.

    PubMed

    Scott, Robert S; Barr, W Andrew

    2014-08-01

    Reconstructions of paleohabitats are necessary aids in understanding hominin evolution. The morphology of species from relevant sites, understood in terms of functional relationships to habitat (termed ecomorphology), offers a direct link to habitat. Bovids are a speciose radiation that includes many habitat specialists and are abundant in the fossil record. Thus, bovids are extremely common in ecomorphological analyses. However, bovid phylogeny and habitat preference are related, which raises the possibility that analyses linking habitat with morphology are not 'taxon free' but 'taxon-dependent.' Here we analyze eight relative dimensions and one shape index of the metatarsal for a sample of 72 bovid species and one antilocaprid. The selected variables have been previously shown to have strong associations with habitat and to have functional explanations for these associations. Phylogenetic generalized least squares analyses of these variables, including habitat and size, resulted in estimates for the parameter lambda (used to model phylogenetic signal) varying from zero to one. Thus, while phylogeny, morphology, and habitat all march together among the bovids, the odds that phylogeny confounds ecomorphological analyses may vary depending on particular morphological characteristics. While large values of lambda do not necessarily indicate that habitat differences are unimportant drivers of morphology, we consider the low value of lambda for relative metatarsal width suggestive that conclusions about habitat built on observations of this particular morphology carry with them less 'phylogenetic risk.' We suggest that the way forward for ecomorphology is grounded in functionally relevant observations and careful consideration of phylogeny designed to bracket probable habitat preferences appropriately. Separate consideration of different morphological variables may help to determine the level of 'phylogenetic risk' attached to conclusions linking habitat and morphology

  13. Habitat degradation affects the summer activity of polar bears.

    PubMed

    Ware, Jasmine V; Rode, Karyn D; Bromaghin, Jeffrey F; Douglas, David C; Wilson, Ryan R; Regehr, Eric V; Amstrup, Steven C; Durner, George M; Pagano, Anthony M; Olson, Jay; Robbins, Charles T; Jansen, Heiko T

    2017-05-01

    Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species' distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using activity data. Location and activity sensor data collected from 1989 to 2014 for 202 adult female polar bears in the Southern Beaufort Sea (SB) and Chukchi Sea (CS) subpopulations were used to compare activity in three habitat types varying in prey availability: (1) land; (2) ice over shallow, biologically productive waters; and (3) ice over deeper, less productive waters. Bears varied activity across and within habitats with the highest activity at 50-75% sea ice concentration over shallow waters. On land, SB bears exhibited variable but relatively high activity associated with the use of subsistence-harvested bowhead whale carcasses, whereas CS bears exhibited low activity consistent with minimal feeding. Both subpopulations had fewer observations in their preferred shallow-water sea ice habitats in recent years, corresponding with declines in availability of this substrate. The substantially higher use of marginal habitats by SB bears is an additional mechanism potentially explaining why this subpopulation has experienced negative effects of sea ice loss compared to the still-productive CS subpopulation. Variability in activity among, and within, habitats suggests that bears alter their behavior in response to habitat conditions, presumably in an attempt to balance prey availability with energy costs.

  14. Convergent Evolution Associated with Habitat Decouples Phenotype from Phylogeny in a Clade of Lizards

    PubMed Central

    Edwards, Shelley; Vanhooydonck, Bieke; Herrel, Anthony; Measey, G. John; Tolley, Krystal A.

    2012-01-01

    Convergent evolution can explain similarity in morphology between species, due to selection on a fitness-enhancing phenotype in response to local environmental conditions. As selective pressures on body morphology may be strong, these have confounded our understanding of the evolutionary relationships between species. Within the speciose African radiation of lacertid lizards (Eremiadini), some species occupy a narrow habitat range (e.g. open habitat, cluttered habitat, strictly rupicolous, or strictly psammophilic), which may exert strong selective pressures on lizard body morphology. Here we show that the overall body plan is unrelated to shared ancestry in the African radiation of Eremiadini, but is instead coupled to habitat use. Comprehensive Bayesian and likelihood phylogenies using multiple representatives from all genera (2 nuclear, 2 mitochondrial markers) show that morphologically convergent species thought to represent sister taxa within the same genus are distantly related evolutionary lineages (Ichnotropis squamulosa and Ichnotropis spp.; Australolacerta rupicola and A. australis). Hierarchical clustering and multivariate analysis of morphological characters suggest that body, and head, width and height (stockiness), all of which are ecologically relevant with respect to movement through habitat, are similar between the genetically distant species. Our data show that convergence in morphology, due to adaptation to similar environments, has confounded the assignment of species leading to misidentification of the taxonomic position of I. squamulosa and the Australolacerta species. PMID:23251601

  15. The global distribution of deep-water Antipatharia habitat

    NASA Astrophysics Data System (ADS)

    Yesson, Chris; Bedford, Faye; Rogers, Alex D.; Taylor, Michelle L.

    2017-11-01

    Antipatharia are a diverse group of corals with many species found in deep water. Many Antipatharia are habitat for associates, have extreme longevity and some species can occur beyond 8500 m depth. As they are major constituents of'coral gardens', which are Vulnerable Marine Ecosystems (VMEs), knowledge of their distribution and environmental requirements is an important pre-requisite for informed conservation planning particularly where the expense and difficulty of deep-sea sampling prohibits comprehensive surveys. This study uses a global database of Antipatharia distribution data to perform habitat suitability modelling using the Maxent methodology to estimate the global extent of black coral habitat suitability. The model of habitat suitability is driven by temperature but there is notable influence from other variables of topography, surface productivity and oxygen levels. This model can be used to predict areas of suitable habitat, which can be useful for conservation planning. The global distribution of Antipatharia habitat suitability shows a marked contrast with the distribution of specimen observations, indicating that many potentially suitable areas have not been sampled, and that sampling effort has been disproportionate to shallow, accessible areas inside marine protected areas (MPAs). Although 25% of Antipatharia observations are located in MPAs, only 7-8% of predicted suitable habitat is protected, which is short of the Convention on Biological Diversity target to protect 10% of ocean habitats by 2020.

  16. Effect of pesticides on microbial communities in container aquatic habitats

    USDA-ARS?s Scientific Manuscript database

    Mosquitoes develop in a variety of aquatic habitats and feed on microbial communities associated with decaying organic matter. These aquatic habitats are often embedded within and around agricultural lands and are frequently exposed to agricultural chemicals. We used a microcosm approach to examine ...

  17. Shallow-water habitats as sources of fallback foods for hominins.

    PubMed

    Wrangham, Richard; Cheney, Dorothy; Seyfarth, Robert; Sarmiento, Esteban

    2009-12-01

    Underground storage organs (USOs) have been proposed as critical fallback foods for early hominins in savanna, but there has been little discussion as to which habitats would have been important sources of USOs. USOs consumed by hominins could have included both underwater and underground storage organs, i.e., from both aquatic and terrestrial habitats. Shallow aquatic habitats tend to offer high plant growth rates, high USO densities, and relatively continuous USO availability throughout the year. Baboons in the Okavango delta use aquatic USOs as a fallback food, and aquatic or semiaquatic USOs support high-density human populations in various parts of the world. As expected given fossilization requisites, the African early- to mid-Pleistocene shows an association of Homo and Paranthropus fossils with shallow-water and flooded habitats where high densities of plant-bearing USOs are likely to have occurred. Given that early hominins in the tropics lived in relatively dry habitats, while others occupied temperate latitudes, ripe, fleshy fruits of the type preferred by African apes would not normally have been available year round. We therefore suggest that water-associated USOs were likely to have been key fallback foods, and that dry-season access to aquatic habitats would have been an important predictor of hominin home range quality. This study differs from traditional savanna chimpanzee models of hominin origins by proposing that access to aquatic habitats was a necessary condition for adaptation to savanna habitats. It also raises the possibility that harvesting efficiency in shallow water promoted adaptations for habitual bipedality in early hominins.

  18. The Importance of Ambient Sound Level to Characterise Anuran Habitat

    PubMed Central

    Goutte, Sandra; Dubois, Alain; Legendre, Frédéric

    2013-01-01

    Habitat characterisation is a pivotal step of any animal ecology study. The choice of variables used to describe habitats is crucial and need to be relevant to the ecology and behaviour of the species, in order to reflect biologically meaningful distribution patterns. In many species, acoustic communication is critical to individuals’ interactions, and it is expected that ambient acoustic conditions impact their local distribution. Yet, classic animal ecology rarely integrates an acoustic dimension in habitat descriptions. Here we show that ambient sound pressure level (SPL) is a strong predictor of calling site selection in acoustically active frog species. In comparison to six other habitat-related variables (i.e. air and water temperature, depth, width and slope of the stream, substrate), SPL had the most important explanatory power in microhabitat selection for the 34 sampled species. Ambient noise was particularly useful in differentiating two stream-associated guilds: torrents and calmer streams dwelling species. Guild definitions were strongly supported by SPL, whereas slope, which is commonly used in stream-associated habitat, had a weak explanatory power. Moreover, slope measures are non-standardized across studies and are difficult to assess at small scale. We argue that including an acoustic descriptor will improve habitat-species analyses for many acoustically active taxa. SPL integrates habitat topology and temporal information (such as weather and hour of the day, for example) and is a simple and precise measure. We suggest that habitat description in animal ecology should include an acoustic measure such as noise level because it may explain previously misunderstood distribution patterns. PMID:24205070

  19. Stomach nematodes (Mastophorus Muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) Habitat at palmyra atoll

    USGS Publications Warehouse

    Lafferty, K.D.; Hathaway, S.A.; Wegmann, A.S.; Shipley, F.S.; Backlin, A.R.; Helm, J.; Fisher, R.N.

    2010-01-01

    Black rats (Rattus rattus) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll. ?? American Society of Parasitologists 2010.

  20. Distribution, abundance, diversity and habitat associations of fishes across a bioregion experiencing rapid coastal development

    NASA Astrophysics Data System (ADS)

    McLean, Dianne L.; Langlois, Tim J.; Newman, Stephen J.; Holmes, Thomas H.; Birt, Matthew J.; Bornt, Katrina R.; Bond, Todd; Collins, Danielle L.; Evans, Scott N.; Travers, Michael J.; Wakefield, Corey B.; Babcock, Russ C.; Fisher, Rebecca

    2016-09-01

    Knowledge of the factors that influence spatial patterns in fish abundance, distribution and diversity are essential for informing fisheries and conservation management. The present study was conducted in the nearshore Pilbara bioregion of north-western Australia where the dynamic marine environment is characterised by large embayments, numerous islands and islets, coexisting with globally significant petrochemical and mineral industries. Within Western Australia, this nearshore bioregion has high biodiversity and is considered to play an essential role in the recruitment of species of commercial importance. To better inform future investigations into both ecological processes and planning scenarios for management, a rapid assessment of the distribution, abundance and associations with nearshore habitats of fishes across the region was conducted. Baited remote underwater stereo-video systems (stereo-BRUVs) were used to simultaneously sample the fish assemblage and habitat composition. Generalised additive mixed models (GAMMs) were used to determine whether the abundance of fishes were related to habitat and a range of environmental variables (visibility, depth, distance to 30 m and 200 m depth isobars, boat ramps and the nearest large embayment (Exmouth Gulf). A diverse fish assemblage comprising 343 species from 58 families was recorded. The abundance and distribution patterns of fishery-target species and of the five most common and abundant species and families were linked positively with areas of high relief, hard coral cover, reef and macroalgae and negatively with the distance to the nearest oceanic waters (200 m depth isobar). This study provides information that can contribute to future marine spatial planning scenarios for management of the Pilbara using a unique, analytical approach that has broad application in biogeography.

  1. Physical habitat classification and instream flow modeling to determine habitat availability during low-flow periods, North Fork Shenandoah River, Virginia

    USGS Publications Warehouse

    Krstolic, Jennifer L.; Hayes, Donald C.; Ruhl, Peter M.

    2006-01-01

    streamflow-gaging stations were used to characterize the flow regime: North Fork Shenandoah River at Cootes Store, Va. (1925-2002), North Fork Shenandoah River at Mount Jackson, Va. (1943-2002), and North Fork Shenandoah River near Strasburg, Va. (1925-2002). The predominant mesohabitat types (14 percent riffle, 67.3 percent run, and 18.7 percent pool) were classified along the entire river (100 miles) to assist in the selection of reaches for hydraulic and fish community data collection. The upper section has predominantly particle substrate, ranging in size from sand to boulders, and the shortest habitat units. The middle section is a transitional section with increased bedrock substrate and habitat unit length. The lower section has predominantly bedrock substrate and the longest habitat units in the river. The model simulations show that weighted usable-habitat area in the upper management section is highest at flows higher than the 25-percent exceedance flow for July, August, and September. During these three months, total weighted usable-habitat area in this section is often less than the simulated maximum weighted usable-habitat area. Habitat area in the middle management section is highest at flows between the 25- and 75-percent exceedance flows for July, August, and September. In the middle section during these months, both the actual weighted usable-habitat area and the simulated maximum weighted usable-habitat area are associated with this flow range. Weighted usable-habitat area in the lower management section is highest at flows lower than the 75-percent exceedance flow for July, August, and September. In the lower section during these three months, some weighted usable-habitat area is available, but the normal range of flows does not include the simulated maximum weighted usable-habitat area. A time-series habitat analysis associated with the historic streamflow, zero water withdrawals, and doubled water withdrawals was completed. During s

  2. Habitat conditions of montane meadows associated with restored and unrestored stream channels of California

    Treesearch

    K. L. Pope; D. S. Montoya; J. N. Brownlee; J. Dierks; T. E. Lisle

    2015-01-01

    Mountain meadow habitats are valued for their ecological importance. They attenuate floods, improve water quality, and support high biodiversity. Many meadow habitats in the western US are degraded, and efforts are increasing to restore these montane meadow ecosystems. Rewatering projects such as pond-and-plug quickly raise the water table by blocking the existing...

  3. Effect of environmental parameters on habitat structural weight and cost

    NASA Technical Reports Server (NTRS)

    Bock, E.; Lambrou, F., Jr.; Simon, M.

    1979-01-01

    Space-settlement conceptual designs were previously accomplished using earth-normal physiological conditions. The habitat weight and cost penalties associated with this conservative design approach are quantified. These penalties are identified by comparison of conservative earth-normal designs with habitats designed to less than earth-normal conditions. Physiological research areas are also recommended as a necessary prerequisite to realizing these potential weight and cost savings. Major habitat structural elements, that is, pressure shell and radiation shielding, for populations of 100, 10,000, and 1,000,000, are evaluated for effects of atmospheric pressure, pseudogravity level, radiation shielding thickness, and habitat configuration.

  4. Distribution of black-tailed jackrabbit habitat determined by GIS in southwestern Idaho

    USGS Publications Warehouse

    Knick, Steven T.; Dyer, D.L.

    1997-01-01

    We developed a multivariate description of black-tailed jackrabbit (Lepus californicus) habitat associations from Geographical Information Systems (GIS) signatures surrounding known jackrabbit locations in the Snake River Birds of Prey National Conservation Area (NCA), in southwestern Idaho. Habitat associations were determined for characteristics within a 1-km radius (approx home range size) of jackrabbits sighted on night spotlight surveys conducted from 1987 through 1995. Predictive habitat variables were number of shrub, agriculture, and hydrography cells, mean and standard deviation of shrub patch size, habitat richness, and a measure of spatial heterogeneity. In winter, jackrabbits used smaller and less variable sizes of shrub patches and areas of higher spatial heterogeneity when compared to summer observations (P 0.05), differed significantly between high and low population phase. We used the Mahalanobis distance statistic to rank all 50-m cells in a 440,000-ha region relative to the multivariate mean habitat vector. On verification surveys to test predicted models, we sighted jackrabbits in areas ranked close to the mean habitat vector. Areas burned by large-scale fires between 1980 and 1992 or in an area repeatedly burned by military training activities had greater Mahalanobis distances from the mean habitat vector than unburned areas and were less likely to contain habitats used by jackrabbits.

  5. 2008 High-Flow Experiment at Glen Canyon Dam-Morphologic Response of Eddy-Deposited Sandbars and Associated Aquatic Backwater Habitats along the Colorado River in Grand Canyon National Park

    USGS Publications Warehouse

    Grams, Paul E.; Schmidt, John C.; Andersen, Matthew E.

    2010-01-01

    The March 2008 high-flow experiment (HFE) at Glen Canyon Dam resulted in sandbar deposition and sandbar reshaping such that the area and volume of associated backwater aquatic habitat in Grand Canyon National Park was greater following the HFE. Analysis of backwater habitat area and volume for 116 locations at 86 study sites, comparing one month before and one month after the HFE, shows that total habitat area increased by 30 percent to as much as a factor of 3 and that volume increased by 80 percent to as much as a factor of 15. These changes resulted from an increase in the area and elevation of sandbars, which isolate backwaters from the main channel, and the scour of eddy return-current channels along the bank where the habitat occurs. Because of this greater relief on the sandbars, backwaters were present across a broader range of flows following the HFE than before the experiment. Reworking of sandbars during diurnal fluctuating flow operations in the first 6 months following the HFE caused sandbar erosion and a reduction of backwater size and abundance to conditions that were 5 to 14 percent greater than existed before the HFE. In the months following the HFE, erosion of sandbars and deposition in eddy return-current channels caused reductions of backwater area and volume. However, sandbar relief was still greater in October 2008 such that backwaters were present across a broader range of discharges than in February 2008. Topographic analyses of the sandbar and backwater morphologic data collected in this study demonstrate that steady flows are associated with a greater amount of continuously available backwater habitat than fluctuating flows, which result in a greater amount of intermittently available habitat. With the exception of the period immediately following the HFE, backwater habitat in 2008 was greater for steady flows associated with dam operations of relatively lower monthly volume (about 227 m3/s) than steady flows associated with dam operations

  6. Evidence for habitat-driven segregation of an estuarine fish assemblage.

    PubMed

    Loureiro, S N; Reis-Filho, J A; Giarrizzo, T

    2016-07-01

    This study examined the spatio-temporal variability in fish assemblage structure and composition following monthly sampling (August 2006 to July 2007). Three estuarine zones (upper, middle and lower) of the unvegetated intertidal and subtidal channel habitats located in the Marapanim Estuary were investigated. In each of these zones, salinity, organic matter and sediment types were measured to assess any correlation between habitat types and the fish fauna. A total of 41 496 fishes, belonging to 76 species and 29 families, was recorded. Recurring changes in both species composition and trophic structure were attributed to seasonal variations, while habitat type played a more permanent role in modifying the structure of fish assemblages. Zooplanktivores (e.g. Lycengraulis grossidens) and herbivores (e.g. Cetengraulis edentulus) used the intertidal habitat almost exclusively and were associated with salinity and substratum composition (gravel, silt and mud). In contrast, benthophages (e.g. Cathorops spixii) and benthophage-ichthyophages (e.g. Cynoscion leiarchus) were primarily associated with the subtidal habitat throughout the estuary and were highly related to the presence of sandy substrata. This study highlighted the intricate roles that local factors (such as habitat connectivity) may have on the distribution of fishes at the assemblage level. As such, incorporating habitat sharing or segregation between species should be viewed as essential for any comparisons of estuaries over large geographic scales, and in particular for conservation planning and management measures. © 2016 The Fisheries Society of the British Isles.

  7. Evaluation of a habitat suitability index model

    USGS Publications Warehouse

    Farmer, A.H.; Cade, B.S.; Stauffer, D.F.

    2002-01-01

    We assisted with development of a model for maternity habitat of the Indiana bat (Myotis soda/is), for use in conducting assessments of projects potentially impacting this endangered species. We started with an existing model, modified that model in a workshop, and evaluated the revised model, using data previously collected by others. Our analyses showed that higher indices of habitat suitability were associated with sites where Indiana bats were present and, thus, the model may be useful for identifying suitable habitat. Utility of the model, however, was based on a single component-density of suitable roost trees. Percentage of landscape in forest did not allow differentiation between sites occupied and not occupied by Indiana bats. Moreover, in spite of a general opinion by participants in the workshop that bodies of water were highly productive feeding areas and that a diversity of feeding habitats was optimal, we found no evidence to support either hypothesis.

  8. Global patterns of fragmentation and connectivity of mammalian carnivore habitat.

    PubMed

    Crooks, Kevin R; Burdett, Christopher L; Theobald, David M; Rondinini, Carlo; Boitani, Luigi

    2011-09-27

    Although mammalian carnivores are vulnerable to habitat fragmentation and require landscape connectivity, their global patterns of fragmentation and connectivity have not been examined. We use recently developed high-resolution habitat suitability models to conduct comparative analyses and to identify global hotspots of fragmentation and connectivity for the world's terrestrial carnivores. Species with less fragmentation (i.e. more interior high-quality habitat) had larger geographical ranges, a greater proportion of habitat within their range, greater habitat connectivity and a lower risk of extinction. Species with higher connectivity (i.e. less habitat isolation) also had a greater proportion of high-quality habitat, but had smaller, not larger, ranges, probably reflecting shorter distances between habitat patches for species with restricted distributions; such species were also more threatened, as would be expected given the negative relationship between range size and extinction risk. Fragmentation and connectivity did not differ among Carnivora families, and body mass was associated with connectivity but not fragmentation. On average, only 54.3 per cent of a species' geographical range comprised high-quality habitat, and more troubling, only 5.2 per cent of the range comprised such habitat within protected areas. Identification of global hotspots of fragmentation and connectivity will help guide strategic priorities for carnivore conservation.

  9. Global patterns of fragmentation and connectivity of mammalian carnivore habitat

    PubMed Central

    Crooks, Kevin R.; Burdett, Christopher L.; Theobald, David M.; Rondinini, Carlo; Boitani, Luigi

    2011-01-01

    Although mammalian carnivores are vulnerable to habitat fragmentation and require landscape connectivity, their global patterns of fragmentation and connectivity have not been examined. We use recently developed high-resolution habitat suitability models to conduct comparative analyses and to identify global hotspots of fragmentation and connectivity for the world's terrestrial carnivores. Species with less fragmentation (i.e. more interior high-quality habitat) had larger geographical ranges, a greater proportion of habitat within their range, greater habitat connectivity and a lower risk of extinction. Species with higher connectivity (i.e. less habitat isolation) also had a greater proportion of high-quality habitat, but had smaller, not larger, ranges, probably reflecting shorter distances between habitat patches for species with restricted distributions; such species were also more threatened, as would be expected given the negative relationship between range size and extinction risk. Fragmentation and connectivity did not differ among Carnivora families, and body mass was associated with connectivity but not fragmentation. On average, only 54.3 per cent of a species' geographical range comprised high-quality habitat, and more troubling, only 5.2 per cent of the range comprised such habitat within protected areas. Identification of global hotspots of fragmentation and connectivity will help guide strategic priorities for carnivore conservation. PMID:21844043

  10. Habitat degradation affects the summer activity of polar bears

    USGS Publications Warehouse

    Ware, Jasmine V.; Rode, Karyn D.; Bromaghin, Jeffrey F.; Douglas, David C.; Wilson, Ryan R.; Regehr, Eric V.; Amstrup, Steven C.; Durner, George M.; Pagano, Anthony M.; Olson, Jay; Robbins, Charles T.; Jansen, Heiko T

    2017-01-01

    Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species’ distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using activity data. Location and activity sensor data collected from 1989 to 2014 for 202 adult female polar bears in the Southern Beaufort Sea (SB) and Chukchi Sea (CS) subpopulations were used to compare activity in three habitat types varying in prey availability: (1) land; (2) ice over shallow, biologically productive waters; and (3) ice over deeper, less productive waters. Bears varied activity across and within habitats with the highest activity at 50–75% sea ice concentration over shallow waters. On land, SB bears exhibited variable but relatively high activity associated with the use of subsistence-harvested bowhead whale carcasses, whereas CS bears exhibited low activity consistent with minimal feeding. Both subpopulations had fewer observations in their preferred shallow-water sea ice habitats in recent years, corresponding with declines in availability of this substrate. The substantially higher use of marginal habitats by SB bears is an additional mechanism potentially explaining why this subpopulation has experienced negative effects of sea ice loss compared to the still-productive CS subpopulation. Variability in activity among, and within, habitats suggests that bears alter their behavior in response to habitat conditions, presumably in an attempt to balance prey availability with energy costs.

  11. Indicators: Shallow Water Habitat/In-stream Fish Habitat

    EPA Pesticide Factsheets

    Shallow water habitat, also referred to as in-stream fish habitat, refers to areas that fish and other aquatic organisms need for concealment, breeding and feeding. This includes large woody snags, boulders, rock ledges, and undercut banks.

  12. The Habitat Connection.

    ERIC Educational Resources Information Center

    Naturescope, 1987

    1987-01-01

    Consists of activities which address the causes of habitat destruction and the effects of habitat loss on animals and plants. Identifies habitat loss as the major reason for the endangerment and extinction of plant and animal species. (ML)

  13. Impacts of Surrounding Land Cover on Headwater Wetland Edaphic Habitat Types and Their Associated Microbial Communities

    NASA Astrophysics Data System (ADS)

    Moon, J. B.; Wardrop, D. H.; Smithwick, E. A.

    2010-12-01

    Although small in size, headwater wetland complexes provide a disproportionate share of microbially mediated ecosystem services to the surrounding landscape and hydroscape. Two services that are of current interest to scientists and managers, given their role in regulating climate and water quality, are the retention and transformation of carbon and nitrogen pools. Although it is the wetland complex’s geographic position between the landscape and hydroscape that creates these hotspots of ecosystem function, continuous shifts in the surrounding scapes can also affect the complex’s transformational capacity through changes to its natural hydrologic disturbance regime and subsequent material fluxes. We have begun to investigate the influence of surrounding land cover and associated differences in hydrology on wetland edaphic habitats and their associated microbial communities. These studies are taking place in wetland complexes located in the headwaters of the Chesapeake Bay Watershed, within the Ridge and Valley Region of central Pennsylvania. Within this region, surrounding land cover ranges from intact forested buffers to a matrix of land cover types (e.g., mixed forest, grassland, and impermeable surfaces). Over a preliminary six-month collection period we found higher frequency and intensity of hydrologic fluctuations in wetlands surrounded by a matrix of land cover types, compared to highly stable saturated conditions of wetland complexes with intact forested buffers. Differences were also found in both the abundances of edaphic habitats as well as in the types of habitats present within these surrounding land cover groups. Wetlands with intact forested buffers had (1) fresh organic residue soils with high overall microbial biomasses and relatively high abundances of microeukaryotic groups, (2) reduced muck soils with relatively large proportions of branched fatty acid microbial groups, and (3) carbon and nutrient depleted sandy mineral soils with relatively

  14. NASA Habitat Demonstration Unit (HDU) Deep Space Habitat Analog

    NASA Technical Reports Server (NTRS)

    Howe, A. Scott; Kennedy, Kriss J.; Gill, Tracy

    2013-01-01

    The NASA Habitat Demonstration Unit (HDU) vertical cylinder habitat was established as a exploration habitat testbed platform for integration and testing of a variety of technologies and subsystems that will be required in a human-occupied planetary surface outpost or Deep Space Habitat (DSH). The HDU functioned as a medium-fidelity habitat prototype from 2010-2012 and allowed teams from all over NASA to collaborate on field analog missions, mission operations tests, and system integration tests to help shake out equipment and provide feedback for technology development cycles and crew training. This paper documents the final 2012 configuration of the HDU, and discusses some of the testing that took place. Though much of the higher-fidelity functionality has 'graduated' into other NASA programs, as of this writing the HDU, renamed Human Exploration Research Analog (HERA), will continue to be available as a volumetric and operational mockup for NASA Human Research Program (HRP) research from 2013 onward.

  15. Chapter 5. Using Habitat Models for Habitat Mapping and Monitoring

    Treesearch

    Samuel A. Cushman; Timothy J. Mersmann; Gretchen G. Moisen; Kevin S. McKelvey; Christina D. Vojta

    2013-01-01

    This chapter provides guidance for applying existing habitat models to map and monitor wildlife habitat. Chapter 2 addresses the use of conceptual models to create a solid foundation for selecting habitat attributes to monitor and to translate these attributes into quantifiable and reportable monitoring measures. Most wildlife species, however, require a complex suite...

  16. 50 CFR 226.202 - Critical habitat for Stellar sea lions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Critical habitat for Stellar sea lions... Critical habitat for Stellar sea lions. Steller Sea Lion (Eumetopias jubatus) (a) Alaska rookeries, haulouts, and associated areas. In Alaska, all major Steller sea lion rookeries identified in Table 1 and...

  17. 50 CFR 226.202 - Critical habitat for Steller sea lions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Critical habitat for Steller sea lions... Critical habitat for Steller sea lions. Steller Sea Lion (Eumetopias jubatus) (a) Alaska rookeries, haulouts, and associated areas. In Alaska, all major Steller sea lion rookeries identified in Table 1 and...

  18. 50 CFR 226.202 - Critical habitat for Stellar sea lions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Critical habitat for Stellar sea lions... Critical habitat for Stellar sea lions. Steller Sea Lion (Eumetopias jubatus) (a) Alaska rookeries, haulouts, and associated areas. In Alaska, all major Steller sea lion rookeries identified in Table 1 and...

  19. 50 CFR 226.202 - Critical habitat for Stellar sea lions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Critical habitat for Stellar sea lions... Critical habitat for Stellar sea lions. Steller Sea Lion (Eumetopias jubatus) (a) Alaska rookeries, haulouts, and associated areas. In Alaska, all major Steller sea lion rookeries identified in Table 1 and...

  20. 50 CFR 226.202 - Critical habitat for Stellar sea lions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Critical habitat for Stellar sea lions... Critical habitat for Stellar sea lions. Steller Sea Lion (Eumetopias jubatus) (a) Alaska rookeries, haulouts, and associated areas. In Alaska, all major Steller sea lion rookeries identified in Table 1 and...

  1. Habitat classification modeling with incomplete data: Pushing the habitat envelope

    USGS Publications Warehouse

    Zarnetske, P.L.; Edwards, T.C.; Moisen, Gretchen G.

    2007-01-01

    Habitat classification models (HCMs) are invaluable tools for species conservation, land-use planning, reserve design, and metapopulation assessments, particularly at broad spatial scales. However, species occurrence data are often lacking and typically limited to presence points at broad scales. This lack of absence data precludes the use of many statistical techniques for HCMs. One option is to generate pseudo-absence points so that the many available statistical modeling tools can be used. Traditional techniques generate pseudoabsence points at random across broadly defined species ranges, often failing to include biological knowledge concerning the species-habitat relationship. We incorporated biological knowledge of the species-habitat relationship into pseudo-absence points by creating habitat envelopes that constrain the region from which points were randomly selected. We define a habitat envelope as an ecological representation of a species, or species feature's (e.g., nest) observed distribution (i.e., realized niche) based on a single attribute, or the spatial intersection of multiple attributes. We created HCMs for Northern Goshawk (Accipiter gentilis atricapillus) nest habitat during the breeding season across Utah forests with extant nest presence points and ecologically based pseudo-absence points using logistic regression. Predictor variables were derived from 30-m USDA Landfire and 250-m Forest Inventory and Analysis (FIA) map products. These habitat-envelope-based models were then compared to null envelope models which use traditional practices for generating pseudo-absences. Models were assessed for fit and predictive capability using metrics such as kappa, thresholdindependent receiver operating characteristic (ROC) plots, adjusted deviance (Dadj2), and cross-validation, and were also assessed for ecological relevance. For all cases, habitat envelope-based models outperformed null envelope models and were more ecologically relevant, suggesting

  2. Biodiversity: Habitat Suitability

    EPA Science Inventory

    Habitat suitability quantifies the relationship between species and habitat, and is evaluated according to the species’ fitness (i.e. proportion of birth rate to death rate). Even though it might maximize evolutionary success, species are not always in habitat that optimizes fit...

  3. The relevance of morphology for habitat use and locomotion in two species of wall lizards

    NASA Astrophysics Data System (ADS)

    Gomes, Verónica; Carretero, Miguel A.; Kaliontzopoulou, Antigoni

    2016-01-01

    Understanding if morphological differences between organisms that occupy different environments are associated to differences in functional performance can suggest a functional link between environmental and morphological variation. In this study we examined three components of the ecomorphological paradigm - morphology, locomotor performance and habitat use - using two syntopic wall lizards endemic to the Iberian Peninsula as a case study to establish whether morphological variation is associated with habitat use and determine the potential relevance of locomotor performance for such an association. Differences in habitat use between both lizards matched patterns of morphological variation. Indeed, individuals of Podarcis guadarramae lusitanicus, which are more flattened, used more rocky environments, whereas Podarcis bocagei, which have higher heads, used more vegetation than rocks. These patterns translated into a significant association between morphology and habitat use. Nevertheless, the two species were only differentiated in some of the functional traits quantified, and locomotor performance did not exhibit an association with morphological traits. Our results suggest that the link between morphology and habitat use is mediated by refuge use, rather than locomotor performance, in this system, and advise caution when extrapolating morphology-performance-environment associations across organisms.

  4. Biodiversity and community composition of sediment macrofauna associated with deep-sea Lophelia pertusa habitats in the Gulf of Mexico

    USGS Publications Warehouse

    Demopoulos, Amanda W.J.; Bourque, Jill R.; Frometa, Janessy

    2014-01-01

    Scleractinian corals create three-dimensional reefs that provide sheltered refuges, facilitate sediment accumulation, and enhance colonization of encrusting fauna. While heterogeneous coral habitats can harbor high levels of biodiversity, their effect on the community composition within nearby sediments remains unclear, particularly in the deep sea. Sediment macrofauna from deep-sea coral habitats (Lophelia pertusa) and non-coral, background sediments were examined at three sites in the northern Gulf of Mexico (VK826, VK906, MC751, 350–500 m depth) to determine whether macrofaunal abundance, diversity, and community composition near corals differed from background soft-sediments. Macrofaunal densities ranged from 26 to 125 individuals 32 cm−2 and were significantly greater near coral versus background sediments only at VK826. Of the 86 benthic invertebrate taxa identified, 16 were exclusive to near-coral habitats, while 14 were found only in background sediments. Diversity (Fisher’s α) and evenness were significantly higher within near-coral sediments only at MC751 while taxon richness was similar among all habitats. Community composition was significantly different both between near-coral and background sediments and among the three primary sites. Polychaetes numerically dominated all samples, accounting for up to 70% of the total individuals near coral, whereas peracarid crustaceans were proportionally more abundant in background sediments (18%) than in those near coral (10%). The reef effect differed among sites, with community patterns potentially influenced by the size of reef habitat. Taxon turnover occurred with distance from the reef, suggesting that reef extent may represent an important factor in structuring sediment communities near L. pertusa. Polychaete communities in both habitats differed from other Gulf of Mexico (GOM) soft sediments based on data from previous studies, and we hypothesize that local environmental conditions found near L

  5. Songbird use of regenerating forest, glade, and edge habitat types

    Treesearch

    Alix D. Fink; Frank R., III Thompson; April A. Tudor

    2006-01-01

    Population numbers of many bird species associated with early-successional or disturbance-dependent habitat types are declining. We used an information-theoretic approach to evaluate hypotheses concerning factors affecting breeding bird densities in different early-successional habitat types. We studied shrubland bird communities in 3- to 5-year-old regenerating forest...

  6. Habitat use and habitat overlap of riparian birds in three elevational zones

    Treesearch

    Deborah M. Finch

    1989-01-01

    I examined patterns of variance in habitat use and habitat overlap in 20 breeding bird species found along a riparian vegetational gradient in southeastern Wyoming to test whether habitat use in species differed (1) from availability of random habitat resources, (2) among elevational zones, and (3) between species that inhabited only one zone and species that occupied...

  7. HABITAT ASSESSMENT METHODS

    EPA Science Inventory

    This chapter summarizes and evaluated the habitat assessment protocols of five agencies, USEPA/EMAP/SW, USGS/NAWQA, USEPA/RBP, Ohio EPA, and MDNR/MBSS. It begins with a description of the origin of the habitat indices most widely used by these agencies. Then the habitat assessmen...

  8. Chinook salmon use of spawning patches: relative roles of habitat quality, size, and connectivity.

    PubMed

    Isaak, Daniel J; Thurow, Russell F; Rieman, Bruce E; Dunham, Jason B

    2007-03-01

    Declines in many native fish populations have led to reassessments of management goals and shifted priorities from consumptive uses to species preservation. As management has shifted, relevant environmental characteristics have evolved from traditional metrics that described local habitat quality to characterizations of habitat size and connectivity. Despite the implications this shift has for how habitats may be prioritized for conservation, it has been rare to assess the relative importance of these habitat components. We used an information-theoretic approach to select the best models from sets of logistic regressions that linked habitat quality, size, and connectivity to the occurrence of chinook salmon (Oncorhynchus tshawytscha) nests. Spawning distributions were censused annually from 1995 to 2004, and data were complemented with field measurements that described habitat quality in 43 suitable spawning patches across a stream network that drained 1150 km2 in central Idaho. Results indicated that the most plausible models were dominated by measures of habitat size and connectivity, whereas habitat quality was of minor importance. Connectivity was the strongest predictor of nest occurrence, but connectivity interacted with habitat size, which became relatively more important when populations were reduced. Comparison of observed nest distributions to null model predictions confirmed that the habitat size association was driven by a biological mechanism when populations were small, but this association may have been an area-related sampling artifact at higher abundances. The implications for habitat management are that the size and connectivity of existing habitat networks should be maintained whenever possible. In situations where habitat restoration is occurring, expansion of existing areas or creation of new habitats in key areas that increase connectivity may be beneficial. Information about habitat size and connectivity also could be used to strategically

  9. Microbial diversity of extreme habitats in human homes.

    PubMed

    Savage, Amy M; Hills, Justin; Driscoll, Katherine; Fergus, Daniel J; Grunden, Amy M; Dunn, Robert R

    2016-01-01

    High-throughput sequencing techniques have opened up the world of microbial diversity to scientists, and a flurry of studies in the most remote and extreme habitats on earth have begun to elucidate the key roles of microbes in ecosystems with extreme conditions. These same environmental extremes can also be found closer to humans, even in our homes. Here, we used high-throughput sequencing techniques to assess bacterial and archaeal diversity in the extreme environments inside human homes (e.g., dishwashers, hot water heaters, washing machine bleach reservoirs, etc.). We focused on habitats in the home with extreme temperature, pH, and chemical environmental conditions. We found a lower diversity of microbes in these extreme home environments compared to less extreme habitats in the home. However, we were nonetheless able to detect sequences from a relatively diverse array of bacteria and archaea. Habitats with extreme temperatures alone appeared to be able to support a greater diversity of microbes than habitats with extreme pH or extreme chemical environments alone. Microbial diversity was lowest when habitats had both extreme temperature and one of these other extremes. In habitats with both extreme temperatures and extreme pH, taxa with known associations with extreme conditions dominated. Our findings highlight the importance of examining interactive effects of multiple environmental extremes on microbial communities. Inasmuch as taxa from extreme environments can be both beneficial and harmful to humans, our findings also suggest future work to understand both the threats and opportunities posed by the life in these habitats.

  10. Habitat-specific foraging of prothonotary warblers: Deducing habitat quality

    USGS Publications Warehouse

    Lyons, J.E.

    2005-01-01

    Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.

  11. Diurnal stream habitat use of juvenile Atlantic salmon, brown trout and rainbow trout in winter

    USGS Publications Warehouse

    Johnson, J. H.; Douglass, K.A.

    2009-01-01

    The diurnal winter habitat of three species of juvenile salmonids was examined in a tributary of Skaneateles Lake, NY to compare habitat differences among species and to determine if species/age classes were selecting specific habitats. A total of 792 observations were made on the depth, velocity, substrate and cover (amount and type) used by sympatric subyearling Atlantic salmon, subyearling brown trout and subyearling and yearling rainbow trout. Subyearling Atlantic salmon occurred in shallower areas with faster velocities and less cover than the other salmonid groups. Subyearling salmon was also the only group associated with substrate of a size larger than the average size substrate in the study reach during both winters. Subyearling brown trout exhibited a preference for vegetative cover. Compared with available habitat, yearling rainbow trout were the most selective in their habitat use. All salmonid groups were associated with more substrate cover in 2002 under high flow conditions. Differences in the winter habitat use of these salmonid groups have important management implications in terms of both habitat protection and habitat enhancement.

  12. Natural or Artificial? Habitat-Use by the Bull Shark, Carcharhinus leucas

    PubMed Central

    Werry, Jonathan M.; Lee, Shing Y.; Lemckert, Charles J.; Otway, Nicholas M.

    2012-01-01

    Background Despite accelerated global population declines due to targeted and illegal fishing pressure for many top-level shark species, the impacts of coastal habitat modification have been largely overlooked. We present the first direct comparison of the use of natural versus artificial habitats for the bull shark, Carcharhinus leucas, an IUCN ‘Near-threatened’ species - one of the few truly euryhaline sharks that utilises natural rivers and estuaries as nursery grounds before migrating offshore as adults. Understanding the value of alternate artificial coastal habitats to the lifecycle of the bull shark is crucial for determining the impact of coastal development on this threatened but potentially dangerous species. Methodology/Findings We used longline surveys and long-term passive acoustic tracking of neonate and juvenile bull sharks to determine the ontogenetic value of natural and artificial habitats to bull sharks associated with the Nerang River and adjoining canals on the Gold Coast, Australia. Long-term movements of tagged sharks suggested a preference for the natural river over artificial habitat (canals). Neonates and juveniles spent the majority of their time in the upper tidal reaches of the Nerang River and undertook excursions into adjoining canals. Larger bull sharks ranged further and frequented the canals closer to the river mouth. Conclusions/Significance Our work suggests with increased destruction of natural habitats, artificial coastal habitat may become increasingly important to large juvenile bull sharks with associated risk of attack on humans. In this system, neonate and juvenile bull sharks utilised the natural and artificial habitats, but the latter was not the preferred habitat of neonates. The upper reaches of tidal rivers, often under significant modification pressure, serve as nursery sites for neonates. Analogous studies are needed in similar systems elsewhere to assess the spatial and temporal generality of this research

  13. Natural or artificial? Habitat-use by the bull shark, Carcharhinus leucas.

    PubMed

    Werry, Jonathan M; Lee, Shing Y; Lemckert, Charles J; Otway, Nicholas M

    2012-01-01

    Despite accelerated global population declines due to targeted and illegal fishing pressure for many top-level shark species, the impacts of coastal habitat modification have been largely overlooked. We present the first direct comparison of the use of natural versus artificial habitats for the bull shark, Carcharhinus leucas, an IUCN 'Near-threatened' species--one of the few truly euryhaline sharks that utilises natural rivers and estuaries as nursery grounds before migrating offshore as adults. Understanding the value of alternate artificial coastal habitats to the lifecycle of the bull shark is crucial for determining the impact of coastal development on this threatened but potentially dangerous species. We used longline surveys and long-term passive acoustic tracking of neonate and juvenile bull sharks to determine the ontogenetic value of natural and artificial habitats to bull sharks associated with the Nerang River and adjoining canals on the Gold Coast, Australia. Long-term movements of tagged sharks suggested a preference for the natural river over artificial habitat (canals). Neonates and juveniles spent the majority of their time in the upper tidal reaches of the Nerang River and undertook excursions into adjoining canals. Larger bull sharks ranged further and frequented the canals closer to the river mouth. Our work suggests with increased destruction of natural habitats, artificial coastal habitat may become increasingly important to large juvenile bull sharks with associated risk of attack on humans. In this system, neonate and juvenile bull sharks utilised the natural and artificial habitats, but the latter was not the preferred habitat of neonates. The upper reaches of tidal rivers, often under significant modification pressure, serve as nursery sites for neonates. Analogous studies are needed in similar systems elsewhere to assess the spatial and temporal generality of this research.

  14. West Foster Creek 2007 Follow-up Habitat Evaluation Procedures (HEP) Report.

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

    Ashley, Paul R.

    A follow-up habitat evaluation procedures (HEP) analysis was conducted on the West Foster Creek (Smith acquisition) wildlife mitigation site in May 2007 to determine the number of additional habitat units to credit Bonneville Power Administration (BPA) for providing funds to enhance and maintain the project site as partial mitigation for habitat losses associated with construction of Grand Coulee Dam. The West Foster Creek 2007 follow-up HEP survey generated 2,981.96 habitat units (HU) or 1.51 HUs per acre for a 34% increase (+751.34 HUs) above baseline HU credit (the 1999 baseline HEP survey generated 2,230.62 habitat units or 1.13 HUs permore » acre). The 2007 follow-up HEP analysis yielded 1,380.26 sharp-tailed grouse (Tympanuchus phasianellus) habitat units, 879.40 mule deer (Odocoileus hemionus) HUs, and 722.29 western meadowlark (Sturnella neglecta) habitat units. Mule deer and sharp-tailed grouse habitat units increased by 346.42 HUs and 470.62 HUs respectively over baseline (1999) survey results due largely to cessation of livestock grazing and subsequent passive restoration. In contrast, the western meadowlark generated slightly fewer habitat units in 2007 (-67.31) than in 1999, because of increased shrub cover, which lowers habitat suitability for that species.« less

  15. Camouflage and individual variation in shore crabs (Carcinus maenas) from different habitats.

    PubMed

    Stevens, Martin; Lown, Alice E; Wood, Louisa E

    2014-01-01

    Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this.

  16. Camouflage and Individual Variation in Shore Crabs (Carcinus maenas) from Different Habitats

    PubMed Central

    Stevens, Martin; Lown, Alice E.; Wood, Louisa E.

    2014-01-01

    Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this. PMID:25551233

  17. Discrete choice modeling of shovelnose sturgeon habitat selection in the Lower Missouri River

    USGS Publications Warehouse

    Bonnot, T.W.; Wildhaber, M.L.; Millspaugh, J.J.; DeLonay, A.J.; Jacobson, R.B.; Bryan, J.L.

    2011-01-01

    Substantive changes to physical habitat in the Lower Missouri River, resulting from intensive management, have been implicated in the decline of pallid (Scaphirhynchus albus) and shovelnose (S. platorynchus) sturgeon. To aid in habitat rehabilitation efforts, we evaluated habitat selection of gravid, female shovelnose sturgeon during the spawning season in two sections (lower and upper) of the Lower Missouri River in 2005 and in the upper section in 2007. We fit discrete choice models within an information theoretic framework to identify selection of means and variability in three components of physical habitat. Characterizing habitat within divisions around fish better explained selection than habitat values at the fish locations. In general, female shovelnose sturgeon were negatively associated with mean velocity between them and the bank and positively associated with variability in surrounding depths. For example, in the upper section in 2005, a 0.5 m s-1 decrease in velocity within 10 m in the bank direction increased the relative probability of selection 70%. In the upper section fish also selected sites with surrounding structure in depth (e.g., change in relief). Differences in models between sections and years, which are reinforced by validation rates, suggest that changes in habitat due to geomorphology, hydrology, and their interactions over time need to be addressed when evaluating habitat selection. Because of the importance of variability in surrounding depths, these results support an emphasis on restoring channel complexity as an objective of habitat restoration for shovelnose sturgeon in the Lower Missouri River.

  18. Habitat Utilization Assessment - Building in Behaviors

    NASA Technical Reports Server (NTRS)

    Whitmore, Mihriban; Blume, Jennifer

    2004-01-01

    Habitability, and the associated architectural and design attributes of an environment, is a powerful performance shaping factor. By identifying how inhabitants use an area, we can draw conclusions about what design or architectural attributes cause what behaviors and systematically design in desired human performance. We are analyzing how a crew uses a long duration habitat and work environment during a four-day underwater mission and identifying certain architectural and design attributes that are related to, and potential enablers of, certain crew behaviors. By identifying how inhabitants use the habitat, we can draw conclusions about what habitability attributes cause what behaviors and systematically design in desired human performance (applicable to NASA's Bioastronautics Human Behavior and Performance Critical Path Roadmap question 6.12). This assessment replicates a methodology reported in a chapter titled "Sociokinetic Analysis as a Tool for Optimization of Environmental Design" by C. Adams.' That study collected video imagery of certain areas of a closed habitat during a 91 day test and from that data calculated time spent in different volumes during the mission, and characterized the behaviors occurring in certain habitat volumes thus concluding various rules for design of such habitats. This study assesses the utilization of the Aquarius Habitat, an underwater station, which will support six Aquanauts for a fourteen-day mission during which the crew will perform specific scientific and engineering studies. Video is recorded for long uninterrupted periods of time during the mission and from that data the time spent in each area is calculated. In addition, qualitative and descriptive analysis of the types of behaviors in each area is performed with the purpose of identifying any behaviors that are not typical of a certain area. If a participant uses an area in a way different from expected, a subsequent analysis of the features of that area may result in

  19. Avian use of Sheyenne Lake and associated habitats in central North Dakota

    USGS Publications Warehouse

    Faanes, Craig A.

    1982-01-01

    A study of avian use of various habitats was conducted in the Sheyenne Lake region of central North Dakota during April-June 1980. Population counts of birds were made in wetlands of various classes, prairie thickets, upland native prairie, shelterbelts, and cropland. About 22,000 breeding bird pairs including 92 species that nested occupied the area. Population means for most species were equal to or greater than statewide means. Red-winged blackbird (Agelaius phoeniceus), yellow-headed blackbird (Xanthocephalus xanthocephalus), mourning dove (Zenaida macroura), and blue-winged teal (Anas discors) were the most numerous species, and made up 32.9% of the total population . Highest densities of breeding birds occurred in shelterbelts, semipermanent wetlands, and prairie thickets. Lowest densities occurred in upland native prairie and cropland. The study area was used by 49.6% of the total avifauna of the State, and 51% of the breeding avifauna of North Dakota probably nested in the study area. The diversity of birds using the area was unusual in that such a large number of species occupied a relatively small area. The close interspersion of many native habitats, several of which are unique in North Dakota, probably accounted for this diversity. Data on dates of occurrence, nesting records, and habitat use are presented for the 175 species recorded in 1980. Observations of significance by refuge staff are also provided.

  20. Bird population and habitat surveys in urban areas

    USGS Publications Warehouse

    DeGraaf, R.M.; Geis, A.D.; Healy, P.A.

    1991-01-01

    Breeding bird populations in six habitats in Columbia. MD, were studied to develop procedures suitable for measuring bird use of residential areas and to identify habitat characteristics that define the distribution of various common bird species. A procedure to measure bird use based on 4-min transect counts on plots measuring 91 m ? 91 m proved better than point counts. Transect counts reduced many of the problems associated with counting birds in urban areas, such as varying noise and visibility. Eighty percent of observations were recorded in the first 4 min. Habitat measurement procedures were examined also. It was found that a subsample of woody tree and shrub crown volumes made on 0.2 ha was highly correlated with similar measures made on 0.8-ha plots.

  1. Habitat use by fishes in coral reefs, seagrass beds and mangrove habitats in the Philippines.

    PubMed

    Honda, Kentaro; Nakamura, Yohei; Nakaoka, Masahiro; Uy, Wilfredo H; Fortes, Miguel D

    2013-01-01

    Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010-2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region.

  2. Habitat Use by Fishes in Coral Reefs, Seagrass Beds and Mangrove Habitats in the Philippines

    PubMed Central

    Honda, Kentaro; Nakamura, Yohei; Nakaoka, Masahiro; Uy, Wilfredo H.; Fortes, Miguel D.

    2013-01-01

    Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010–2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region. PMID:23976940

  3. From ground pools to treeholes: convergent evolution of habitat and phenotype in Aedes mosquitoes.

    PubMed

    Soghigian, John; Andreadis, Theodore G; Livdahl, Todd P

    2017-12-19

    Invasive mosquito species are responsible for millions of vector-borne disease cases annually. The global invasive success of Aedes mosquitoes such as Aedes aegypti and Aedes albopictus has relied on the human transport of immature stages in container habitats. However, despite the importance of these mosquitoes and this ecological specialization to their widespread dispersal, evolution of habitat specialization in this group has remained largely unstudied. We use comparative methods to evaluate the evolution of habitat specialization and its potential influence on larval morphology, and evaluate whether container dwelling and invasiveness are monophyletic in Aedes. We show that habitat specialization has evolved repeatedly from ancestral ground pool usage to specialization in container habitats. Furthermore, we find that larval morphological scores are significantly associated with larval habitat when accounting for evolutionary relationships. We find that Ornstein-Uhleinbeck models with unique optima for each larval habitat type are preferred over several other models based predominantly on neutral processes, and that OU models can reliably simulate real morphological data. Our results demonstrate that multiple lineages of Aedes have convergently evolved a key trait associated with invasive success: the use of container habitats for immature stages. Moreover, our results demonstrate convergence in morphological characteristics as well, and suggest a role of adaptation to habitat specialization in driving phenotypic diversity in this mosquito lineage. Finally, our results highlight that the genus Aedes is not monophyletic.

  4. Data Collection and Simulation of Ecological Habitat and Recreational Habitat in the Shenandoah River, Virginia

    USGS Publications Warehouse

    Krstolic, Jennifer L.

    2015-01-01

    Time-series analyses were used to investigate changes in habitat availability with increased water withdrawals of 10, 20, and almost 50 percent (48.6 percent) up to the 2040 amounts projected by local water supply plans. Adult and sub-adult smallmouth bass frequently had habitat availability outside the normal range for habitat conditions during drought years, yet 10- or 20-percent increases in withdrawals did not contribute to a large reduction in habitat. When withdrawals were increased by 50 percent, there was an additional decrease in habitat. During 2002 drought scenarios, reduced habitat availability for sub-adult redbreast sunfish or river chub was only slightly evident with 50-percent increased withdrawal scenarios. Recreational habitat represented by canoeing decreased lower than normal during the 2002 drought. For a recent normal year, like 2012, increased water-withdrawal scenarios did not affect habitat availability for fish such as adult and sub-adult smallmouth bass, sub-adult redbreast sunfish, or river chub. Canoeing habitat availability was within the normal range most of 2012, and increased water-withdrawal scenarios showed almost no affect. For both ecological fish habitat and recreational canoeing habitat, the antecedent conditions (habitat within normal range of habitat or below normal) appear to govern whether additional water withdrawals will affect habitat availability. As human populations and water demands increase, many of the ecological or recreational stresses may be lessened by managing the timing of water withdrawals from the system.

  5. Sensitivity of wildlife habitat models to uncertainties in GIS data

    NASA Technical Reports Server (NTRS)

    Stoms, David M.; Davis, Frank W.; Cogan, Christopher B.

    1992-01-01

    Decision makers need to know the reliability of output products from GIS analysis. For many GIS applications, it is not possible to compare these products to an independent measure of 'truth'. Sensitivity analysis offers an alternative means of estimating reliability. In this paper, we present a CIS-based statistical procedure for estimating the sensitivity of wildlife habitat models to uncertainties in input data and model assumptions. The approach is demonstrated in an analysis of habitat associations derived from a GIS database for the endangered California condor. Alternative data sets were generated to compare results over a reasonable range of assumptions about several sources of uncertainty. Sensitivity analysis indicated that condor habitat associations are relatively robust, and the results have increased our confidence in our initial findings. Uncertainties and methods described in the paper have general relevance for many GIS applications.

  6. Habitat use by fishes in groundwater-dependent streams of southern Oklahoma

    USGS Publications Warehouse

    Seilheimer, Titus S.; Fisher, William L.

    2010-01-01

    Habitat use by fishes in groundwater-dependent ecosystems with springs and spring-fed creeks is not widely studied or well understood. We evaluated habitat use by three disjunct populations of fish species (Phoxinus erythrogaster, Nocomis asper and Etheostoma microperca) and, a widespread species, E. spectabile in spring-fed streams draining the Arbuckle-Simpson aquifer of southern Oklahoma. Habitat preference for each species was classified based on depth, velocity, substrate and cover. Phoxinus erthyrogaster and N. asper were associated with pools with little cover, while E. microperca was found in heavily vegetated areas. Etheostoma spectabile used habitat in riffles with rapid velocity and large substrate types. We classified habitat selection and avoidance with Chesson's α and observed significant differences in habitat use among species in the study sites. Overall differences in habitat use for P. erythrogaster among the three study sites were primarily related to differences in available habitat between springs. Our study provides vital ecological information about disjunct populations of groundwater-dependent fishes in an aquifer that is experiencing development pressure for water abstraction.

  7. Characterisation of larval habitats, species composition and factors associated with the seasonal abundance of mosquito fauna in Gezira, Sudan.

    PubMed

    Mahgoub, Mostafa M; Kweka, Eliningaya J; Himeidan, Yousif E

    2017-02-08

    Larval source management (LSM), which requires an understanding of the ecology and composition of the local mosquito fauna, is an important parameter in successful vector control programmes. The present study was conducted to understand the distribution of larval habitats, species composition and factors associated with the seasonal abundance of mosquito larvae in Gezira irrigation Scheme in Gezira state, central Sudan. Cross-sectional larval surveys were carried out in the communities of Barakat (urban) and El-Kareiba (semi-urban), in Wad Madani, Gezira. A standard dipper was used for sampling larvae in all possible breeding sites and enamel bowls were employed for larvae sorting. Habitats were characterised using physical features and all larvae specimens were identified morphologically. A total of 331 larval habitats were surveyed, out of which 166 were found to be positive breeding sites for Anopheles (56.78%), Culicinae (29.67%) and Aedes (13.55%) species. A total of 5 525 larvae collected were categorised as Culex (2 617, 47.37%), Anopheles (2 600, 47.06%) and Aedes (308, 5.57%). There was a high number of positive habitats during the rainy season, while the lowest proportion was reported during the hot dry season, in both study sites (Barakat [χ 2  = 10.641, P = 0.0090], El-Kareiba [χ 2  = 23.765, P = 0.0001]). The main breeding site for Anopheles larvae was leaking water pipes (51.5%), followed by irrigation channels (34.2%), hoof prints (6.4%), tyre tracks (5.5%) and water tanks (2.4%). A logistic regression analysis showed that the abundance of Anopheles larvae was reduced by the presence of predators (backswimmers, tadpoles) and grass cover. Adult productivity (number of adult females emerged/m 2 ) was not homogeneousfor all habitats; the highest productivity was found in irrigation channels (0.78 females/m 2 ) for Anopheles, and in septic tanks (2.86 females/m 2 ) for Culicinae and (0.86 females/m 2 ) for Aedes. Anopheles arabiensis

  8. Wildlife Habitat Restoration: Chapter 12

    USGS Publications Warehouse

    Conway, Courtney J.; Borgmann, Kathi L.; Morrison, Michael L.; Mathewson, Heather A.

    2015-01-01

    As the preceding chapters point out, many wildlife species and the habitat they depend on are in peril. However, opportunities exist to restore habitat for many imperiled wildlife species. But what is wildlife habitat restoration? We begin this chapter by defining habitat restoration and then provide recommendations on how to maximize success of future habitat restoration efforts for wildlife. Finally, we evaluate whether we have been successful in restoring wildlife habitat and supply recommendations to advance habitat restoration. Successful restoration requires clear and explicit goals that are based on our best understanding of what the habitat was like prior to the disturbing event. Ideally, a restoration project would include: (1) a summary of prerestoration conditions that define the existing status of wildlife populations and their habitat; (2) a description of habitat features required by the focal or indicator species for persistence; (3) an a priori description of measurable, quantitative metrics that define restoration goals and measures of success; (4) a monitoring plan; (5) postrestoration comparisons of habitat features and wildlife populations with adjacent unmodified areas that are similar to the restoration site; and (6) expert review of the entire restoration plan (i.e., the five aforementioned components).

  9. Differential habitat use or intraguild interactions: What structures a carnivore community?

    Treesearch

    Matthew E. Gompper; Damon B. Lesmeister; Justina C. Ray; Jay R. Malcolm; Roland Kays; Aaron W. Reed

    2016-01-01

    Differential habitat use and intraguild competition are both thought to be important drivers of animal population sizes and distributions. Habitat associations for individual species are well-established, and interactions between particular pairs of species have been highlighted in many focal studies. However, community-wide assessments of the relative strengths of...

  10. Chinook salmon use of spawning patches: Relative roles of habitat quality, size, and connectivity

    USGS Publications Warehouse

    Isaak, D.J.; Thurow, R.F.; Rieman, B.E.; Dunham, J.B.

    2007-01-01

    Declines in many native fish populations have led to reassessments of management goals and shifted priorities from consumptive uses to species preservation. As management has shifted, relevant environmental characteristics have evolved from traditional metrics that described local habitat quality to characterizations of habitat size and connectivity. Despite the implications this shift has for how habitats may be prioritized for conservation, it has been rare to assess the relative importance of these habitat components. We used an information-theoretic approach to select the best models from sets of logistic regressions that linked habitat quality, size, and connectivity to the occurrence of chinook salmon (Oncorhynchus tshawytscha) nests. Spawning distributions were censused annually from 1995 to 2004, and data were complemented with field measurements that described habitat quality in 43 suitable spawning patches across a stream network that drained 1150 km 2 in central Idaho. Results indicated that the most plausible models were dominated by measures of habitat size and connectivity, whereas habitat quality was of minor importance. Connectivity was the strongest predictor of nest occurrence, but connectivity interacted with habitat size, which became relatively more important when populations were reduced. Comparison of observed nest distributions to null model predictions confirmed that the habitat size association was driven by a biological mechanism when populations were small, but this association may have been an area-related sampling artifact at higher abundances. The implications for habitat management are that the size and connectivity of existing habitat networks should be maintained whenever possible. In situations where habitat restoration is occurring, expansion of existing areas or creation of new habitats in key areas that increase connectivity may be beneficial. Information about habitat size and connectivity also could be used to strategically

  11. An evaluation of powerline rights-of-way as habitat for early-successional shrubland birds

    Treesearch

    David I. King; Bruce E. Byers

    2002-01-01

    Recent population declines among bird species that breed in early-successional shrubland habitats in the eastern United States have been associated with declines in habitat availability. Forest succession has eliminated shrublands in many locations, but powerline rights-of-way constitute a potential reservoir of shrubland habitat for birds. We studied 2 populations of...

  12. Ord's kangaroo rats living in floodplain habitats: Factors contributing to habitat attraction

    USGS Publications Warehouse

    Miller, M.S.; Wilson, K.R.; Andersen, D.C.

    2003-01-01

    High densities of an aridland granivore, Ord's kangaroo rat (Dipodomys ordii), have been documented in floodplain habitats along the Yampa River in northwestern Colorado. Despite a high probability of inundation and attendant high mortality during the spring flood period, the habitat is consistently recolonized. To understand factors that potentially make riparian habitats attractive to D. ordii, we compared density and spatial pattern of seeds, density of a competitor (western harvester ant, Pogonomyrmex occidentalis), and digging energetics within floodplain habitats and between floodplain and adjacent upland habitats. Seed density within the floodplain was greatest in the topographically high (rarely flooded) floodplain and lowest immediately after a spring flood in the topographically low (frequently flooded) floodplain. Seed densities in adjacent upland habitat that never floods were higher than the lowest floodplain habitat. In the low floodplain prior to flooding, seeds had a clumped spatial pattern, which D. ordii is adept at exploiting; after spring flooding, a more random pattern resulted. Populations of the western harvester ant were low in the floodplain relative to the upland. Digging by D. ordii was energetically less expensive in floodplain areas than in upland areas. Despite the potential for mortality due to annual spring flooding, the combination of less competition from harvester ants and lower energetic costs of digging might promote the use of floodplain habitat by D. ordii.

  13. Herpetofauna of the cedar glades and associated habitats of the Inner Central Basin of middle Tennessee

    USGS Publications Warehouse

    Niemiller, M.L.; Graham, Reynolds R.; Glorioso, B.M.; Spiess, J.; Miller, B.T.

    2011-01-01

    The cedar glades and barrens of the Inner Central Basin (ICB) of middle Tennessee support a unique and diverse flora and fauna and represent some of the state's most valued natural areas. We conducted herpetofaunal inventories of the cedar glades, associated barrens, cedar-hardwood forest, and adjacent aquatic habitats of the Stones River drainage of Middle Tennessee, focusing our sampling effort primarily at seven state- or federally owned properties in Rutherford and Wilson counties. These properties included Stones River National Battlefield (SRNB), Flat Rock State Natural Area (FRSNA), Vesta Cedar Glade State Natural Area (VSNA), Fall Creek Recreation Area (FCRA) on J. Percy Priest Wildlife Management Area, Cedars of Lebanon State Forest (CLSF), Cedars of Lebanon State Forest Natural Area (CLSNA), and Cedars of Lebanon State Park (CLSP). We used a variety of inventory techniques in terrestrial, aquatic, and subterranean habitats to survey these properties periodically from 1989 to 2010. We documented 49 species (22 amphibian and 27 reptile) accounting for 75.4% of the 65 herpetofaunal species thought to occur in the ICB, including records for Cemophora coccinea, Aneides aeneus, Gyrinophilus palleucus, Ambystoma barbouri, and Pseudotriton montanus. We found differences in alpha and beta diversity between sites, with the CLSF complex containing a high of 41 herpetofaunal species and FRSNA containing a low of 23 species. Beta diversity comparisons indicated similarity in amphibian species composition between FRSNA and CLSF and between SRNB and CLSF (9 shared species), and in reptile species composition between VSNA and the CLSF complex (16 shared species). We compare the results of our inventory with two previous studies conducted in the area and discuss the relative abundance, conservation, and threats to the herpetofaunal community of these habitats.

  14. Migrating birds’ use of stopover habitat in the southwestern United States

    USGS Publications Warehouse

    Ruth, Janet M.; Diehl, R.H.; Felix, R.K.

    2012-01-01

    In the arid Southwest, migratory birds are known to use riparian stopover habitats; we know less about how migrants use other habitat types during migratory stopover. Using radar data and satellite land-cover data, we determined the habitats with which birds are associated during migration stopover. Bird densities differed significantly by habitat type at all sites in at least one season. In parts of Arizona and New Mexico upland forest supported high densities of migrants, especially in fall. Developed habitat, in areas with little upland forest, also supported high densities of migrants. Scrub/shrub and grassland habitats supported low to intermediate densities, but because these habitat types dominate the Southwestern landscape, they may provide stopover habitat for larger numbers of migratory birds than previously recognized. These results are complicated by continuing challenges related to target identity (i.e., distinguishing among birds, arthropods and bats). Our results suggest that it is too simplistic to (1) consider the arid West as a largely inhospitable landscape in which there are only relatively small oases of habitat that provide the resources needed by all migrants, (2) think of western riparian and upland forests as supporting the majority of migrants in all cases, and (3) consider a particular habitat unimportant for stopover solely on the basis of low densities of migrants.

  15. Relationships between human disturbance and wildlife land use in urban habitat fragments.

    PubMed

    Markovchick-Nicholls, Lisa; Regan, Helen M; Deutschman, Douglas H; Widyanata, Astrid; Martin, Barry; Noreke, Lani; Hunt, Timothy Ann

    2008-02-01

    Habitat remnants in urbanized areas typically conserve biodiversity and serve the recreation and urban open-space needs of human populations. Nevertheless, these goals can be in conflict if human activity negatively affects wildlife. Hence, when considering habitat remnants as conservation refuges it is crucial to understand how human activities and land uses affect wildlife use of those and adjacent areas. We used tracking data (animal tracks and den or bed sites) on 10 animal species and information on human activity and environmental factors associated with anthropogenic disturbance in 12 habitat fragments across San Diego County, California, to examine the relationships among habitat fragment characteristics, human activity, and wildlife presence. There were no significant correlations of species presence and abundance with percent plant cover for all species or with different land-use intensities for all species, except the opossum (Didelphis virginiana), which preferred areas with intensive development. Woodrats (Neotoma spp.) and cougars (Puma concolor) were associated significantly and positively and significantly and negatively, respectively, with the presence and prominence of utilities. Woodrats were also negatively associated with the presence of horses. Raccoons (Procyon lotor) and coyotes (Canis latrans) were associated significantly and negatively and significantly and positively, respectively, with plant bulk and permanence. Cougars and gray foxes (Urocyon cinereoargenteus) were negatively associated with the presence of roads. Roadrunners (Geococcyx californianus) were positively associated with litter. The only species that had no significant correlations with any of the environmental variables were black-tailed jackrabbits (Lepus californicus) and mule deer (Odocoileus hemionus). Bobcat tracks were observed more often than gray foxes in the study area and bobcats correlated significantly only with water availability, contrasting with results from

  16. Estimating the effects of habitat and biological interactions in an avian community

    USGS Publications Warehouse

    Dorazio, Robert M.; Connor, Edward F.; Askins, Robert A.

    2015-01-01

    We used repeated sightings of individual birds encountered in community-level surveys to investigate the relative roles of habitat and biological interactions in determining the distribution and abundance of each species. To analyze these data, we developed a multispecies N-mixture model that allowed estimation of both positive and negative correlations between abundances of different species while also estimating the effects of habitat and the effects of errors in detection of each species. Using a combination of single- and multispecies N-mixture modeling, we examined for each species whether our measures of habitat were sufficient to account for the variation in encounter histories of individual birds or whether other habitat variables or interactions with other species needed to be considered. In the community that we studied, habitat appeared to be more influential than biological interactions in determining the distribution and abundance of most avian species. Our results lend support to the hypothesis that abundances of forest specialists are negatively affected by forest fragmentation. Our results also suggest that many species were associated with particular types of vegetation as measured by structural attributes of the forests. The abundances of 6 of the 73 species observed in our study were strongly correlated. These species included large birds (American Crow and Red-winged Blackbird) that forage on the ground in open habitats and small birds (Red-eyed Vireo, House Wren, Hooded Warbler, and Prairie Warbler) that are associated with dense shrub cover. Species abundances were positively correlated within each size group and negatively correlated between groups. Except for the American Crow, which preys on eggs and nestlings of small song birds, none of the other 5 species is known to display direct interactions, so we suspect that the correlations may have been associated with species-specific responses to habitat components not adequately measured by

  17. Guild-specific responses of avian species richness to LiDAR-derived habitat heterogeneity

    USGS Publications Warehouse

    Weisberg, Peter J.; Dilts, Thomas E.; Becker, Miles E.; Young, Jock S.; Wong-Kone, Diane C.; Newton, Wesley E.; Ammon, Elisabeth M.

    2014-01-01

    Ecological niche theory implies that more heterogeneous habitats have the potential to support greater biodiversity. Positive heterogeneity-diversity relationships have been found for most studies investigating animal taxa, although negative relationships also occur and the scale dependence of heterogeneity-diversity relationships is little known. We investigated multi-scale, heterogeneity-diversity relationships for bird communities in a semi-arid riparian landscape, using airborne LiDAR data to derive key measures of structural habitat complexity. Habitat heterogeneity-diversity relationships were generally positive, although the overall strength of relationships varied across avian life history guilds (R2 range: 0.03–0.41). Best predicted were the species richness indices of cavity nesters, habitat generalists, woodland specialists, and foliage foragers. Heterogeneity-diversity relationships were also strongly scale-dependent, with strongest associations at the 200-m scale (4 ha) and weakest associations at the 50-m scale (0.25 ha). Our results underscore the value of LiDAR data for fine-grained quantification of habitat structure, as well as the need for biodiversity studies to incorporate variation among life-history guilds and to simultaneously consider multiple guild functional types (e.g. nesting, foraging, habitat). Results suggest that certain life-history guilds (foliage foragers, cavity nesters, woodland specialists) are more susceptible than others (ground foragers, ground nesters, low nesters) to experiencing declines in local species richness if functional elements of habitat heterogeneity are lost. Positive heterogeneity-diversity relationships imply that riparian conservation efforts need to not only provide high-quality riparian habitat locally, but also to provide habitat heterogeneity across multiple scales.

  18. Guild-specific responses of avian species richness to LiDAR-derived habitat heterogeneity

    NASA Astrophysics Data System (ADS)

    Weisberg, Peter J.; Dilts, Thomas E.; Becker, Miles E.; Young, Jock S.; Wong-Kone, Diane C.; Newton, Wesley E.; Ammon, Elisabeth M.

    2014-08-01

    Ecological niche theory implies that more heterogeneous habitats have the potential to support greater biodiversity. Positive heterogeneity-diversity relationships have been found for most studies investigating animal taxa, although negative relationships also occur and the scale dependence of heterogeneity-diversity relationships is little known. We investigated multi-scale, heterogeneity-diversity relationships for bird communities in a semi-arid riparian landscape, using airborne LiDAR data to derive key measures of structural habitat complexity. Habitat heterogeneity-diversity relationships were generally positive, although the overall strength of relationships varied across avian life history guilds (R2 range: 0.03-0.41). Best predicted were the species richness indices of cavity nesters, habitat generalists, woodland specialists, and foliage foragers. Heterogeneity-diversity relationships were also strongly scale-dependent, with strongest associations at the 200-m scale (4 ha) and weakest associations at the 50-m scale (0.25 ha). Our results underscore the value of LiDAR data for fine-grained quantification of habitat structure, as well as the need for biodiversity studies to incorporate variation among life-history guilds and to simultaneously consider multiple guild functional types (e.g. nesting, foraging, habitat). Results suggest that certain life-history guilds (foliage foragers, cavity nesters, woodland specialists) are more susceptible than others (ground foragers, ground nesters, low nesters) to experiencing declines in local species richness if functional elements of habitat heterogeneity are lost. Positive heterogeneity-diversity relationships imply that riparian conservation efforts need to not only provide high-quality riparian habitat locally, but also to provide habitat heterogeneity across multiple scales.

  19. Habitat fragmentation in coastal southern California disrupts genetic connectivity in the cactus wren (Campylorhynchus brunneicapillus)

    USGS Publications Warehouse

    Barr, Kelly R.; Kus, Barbara E.; Preston, Kristine; Howell, Scarlett; Perkins, Emily; Vandergast, Amy

    2015-01-01

    Achieving long-term persistence of species in urbanized landscapes requires characterizing population genetic structure to understand and manage the effects of anthropogenic disturbance on connectivity. Urbanization over the past century in coastal southern California has caused both precipitous loss of coastal sage scrub habitat and declines in populations of the cactus wren (Campylorhynchus brunneicapillus). Using 22 microsatellite loci, we found that remnant cactus wren aggregations in coastal southern California comprised 20 populations based on strict exact tests for population differentiation, and 12 genetic clusters with hierarchical Bayesian clustering analyses. Genetic structure patterns largely mirrored underlying habitat availability, with cluster and population boundaries coinciding with fragmentation caused primarily by urbanization. Using a habitat model we developed, we detected stronger associations between habitat-based distances and genetic distances than Euclidean geographic distance. Within populations, we detected a positive association between available local habitat and allelic richness and a negative association with relatedness. Isolation-by-distance patterns varied over the study area, which we attribute to temporal differences in anthropogenic landscape development. We also found that genetic bottleneck signals were associated with wildfire frequency. These results indicate that habitat fragmentation and alterations have reduced genetic connectivity and diversity of cactus wren populations in coastal southern California. Management efforts focused on improving connectivity among remaining populations may help to ensure population persistence.

  20. Lunar base habitat designs: Characterizing the environment, and selecting habitat designs for future trade-offs

    NASA Technical Reports Server (NTRS)

    Ganapathi, Gani B.; Ferrall, Joseph; Seshan, P. K.

    1993-01-01

    A survey of distinct conceptual lunar habitat designs covering the pre- and post-Apollo era is presented. The impact of the significant lunar environmental challenges such as temperature, atmosphere, radiation, soil properties, meteorites, and seismic activity on the habitat design parameters are outlined. Over twenty habitat designs were identified and classified according to mission type, crew size; total duration of stay, modularity, environmental protection measures, and emplacement. Simple selection criteria of (1) post-Apollo design, (2) uniqueness of the habitat design, (3) level of thoroughness in design layout, (4) habitat dimensions are provided, and (5) materials of construction for the habitat shell are specified, are used to select five habitats for future trade studies. Habitat emplacement scenarios are created to examine the possible impact of emplacement of the habitat in different locations, such as lunar poles vs. equatorial, above ground vs. below ground, etc.

  1. Habitat assessment for giant pandas in the Qinling Mountain region of China

    USGS Publications Warehouse

    Feng, Tian-Tian; Van Manen, Frank T.; Zhao, Na-Xun; Li, Ming; Wei, Fu-Wen

    2009-01-01

    Because habitat loss and fragmentation threaten giant pandas (Ailuropoda melanoleuca), habitat protection and restoration are important conservation measures for this endangered species. However, distribution and value of potential habitat to giant pandas on a regional scale are not fully known. Therefore, we identified and ranked giant panda habitat in Foping Nature Reserve, Guanyinshan Nature Reserve, and adjacent areas in the Qinling Mountains of China. We used Mahalanobis distance and 11 digital habitat layers to develop a multivariate habitat signature associated with 247 surveyed giant panda locations, which we then applied to the study region. We identified approximately 128 km2 of giant panda habitat in Foping Nature Reserve (43.6% of the reserve) and 49 km2 in Guanyinshan Nature Reserve (33.6% of the reserve). We defined core habitat areas by incorporating a minimum patch-size criterion (5.5 km2) based on home-range size. Percentage of core habitat area was higher in Foping Nature Reserve (41.8% of the reserve) than Guanyinshan Nature Reserve (26.3% of the reserve). Within the larger analysis region, Foping Nature Reserve contained 32.7% of all core habitat areas we identified, indicating regional importance of the reserve. We observed a negative relationship between distribution of core areas and presence of roads and small villages. Protection of giant panda habitat at lower elevations and improvement of habitat linkages among core habitat areas are important in a regional approach to giant panda conservation.

  2. Do management actions to restore rare habitat benefit native fish conservation? Distribution of juvenile native fish among shoreline habitats of the Colorado River

    USGS Publications Warehouse

    Dodrill, Michael J.; Yackulic, Charles B.; Gerig, Brandon; Pine, William E.; Korman, Josh; Finch, Colton

    2015-01-01

    Many management actions in aquatic ecosystems are directed at restoring or improving specific habitats to benefit fish populations. In the Grand Canyon reach of the Colorado River, experimental flow operations as part of the Glen Canyon Dam Adaptive Management Program have been designed to restore sandbars and associated backwater habitats. Backwaters can have warmer water temperatures than other habitats, and native fish, including the federally endangered humpback chub Gila cypha, are frequently observed in backwaters, leading to a common perception that this habitat is critical for juvenile native fish conservation. However, it is unknown how fish densities in backwaters compare with that in other habitats or what proportion of juvenile fish populations reside in backwaters. Here, we develop and fit multi-species hierarchical models to estimate habitat-specific abundances and densities of juvenile humpback chub, bluehead suckerCatostomus discobolus, flannelmouth sucker Catostomus latipinnis and speckled dace Rhinichthys osculus in a portion of the Colorado River. Densities of all four native fish were greatest in backwater habitats in 2009 and 2010. However, backwaters are rare and ephemeral habitats, so they contain only a small portion of the overall population. For example, the total abundance of juvenile humpback chub in this study was much higher in talus than in backwater habitats. Moreover, when we extrapolated relative densities based on estimates of backwater prevalence directly after a controlled flood, the majority of juvenile humpback chub were still found outside of backwaters. This suggests that the role of controlled floods in influencing native fish population trends may be limited in this section of the Colorado River. 

  3. The airspace is habitat

    USGS Publications Warehouse

    Diehl, Robert H.

    2013-01-01

    A preconception concerning habitat persists and has gone unrecognized since use of the term first entered the lexicon of ecological and evolutionary biology many decades ago. Specifically, land and water are considered habitats, while the airspace is not. This might at first seem a reasonable, if unintended, demarcation, since years of education and personal experience as well as limits to perception predispose a traditional view of habitat. Nevertheless, the airspace satisfies the definition and functional role of a habitat, and its recognition as habitat may have implications for policy where expanding anthropogenic development of airspace could impact the conservation of species and subject parts of the airspace to formalized legal protection.

  4. Evaluating habitat associations of a fish assemblage at multiple spatial scales in a minimally disturbed stream using low-cost remote sensing

    USGS Publications Warehouse

    Cheek, Brandon D.; Grabowski, Timothy B.; Bean, Preston T.; Groeschel, Jillian R.; Magnelia, Stephan J.

    2016-01-01

    Habitat heterogeneity at multiple scales is a major factor affecting fish assemblage structure. However, assessments that examine these relationships at multiple scales concurrently are lacking. The lack of assessments at these scales is a critical gap in understanding as conservation and restoration efforts typically work at these levels.A combination of low-cost side-scan sonar surveys, aerial imagery using an unmanned aerial vehicle, and fish collections were used to evaluate the relationship between physicochemical and landscape variables at various spatial scales (e.g. micro-mesohabitat, mesohabitat, channel unit, stream reach) and stream–fish assemblage structure and habitat associations in the South Llano River, a spring-fed second-order stream on the Edwards Plateau in central Texas during 2012–2013.Low-cost side-scan sonar surveys have not typically been used to generate data for riverscape assessments of assemblage structure, thus the secondary objective was to assess the efficacy of this approach.The finest spatial scale (micro-mesohabitat) and the intermediate scale (channel unit) had the greatest explanatory power for variation in fish assemblage structure.Many of the fish endemic to the Edwards Plateau showed similar associations with physicochemical and landscape variables suggesting that conservation and restoration actions targeting a single endemic species may provide benefits to a large proportion of the endemic species in this system.Low-cost side-scan sonar proved to be a cost-effective means of acquiring information on the habitat availability of the entire river length and allowed the assessment of how a full suite of riverscape-level variables influenced local fish assemblage structure.

  5. Assessment and management of dead-wood habitat

    USGS Publications Warehouse

    Hagar, Joan

    2007-01-01

    The Bureau of Land Management (BLM) is in the process of revising its resource management plans for six districts in western and southern Oregon as the result of the settlement of a lawsuit brought by the American Forest Resource Council. A range of management alternatives is being considered and evaluated including at least one that will minimize reserves on O&C lands. In order to develop the bases for evaluating management alternatives, the agency needs to derive a reasonable range of objectives for key issues and resources. Dead-wood habitat for wildlife has been identified as a key resource for which decision-making tools and techniques need to be refined and clarified. Under the Northwest Forest Plan, reserves were to play an important role in providing habitat for species associated with dead wood (U.S. Department of Agriculture Forest Service and U.S. Department of the Interior Bureau of Land Management, 1994). Thus, the BLM needs to: 1) address the question of how dead wood will be provided if reserves are not included as a management strategy in the revised Resource Management Plan, and 2) be able to evaluate the effects of alternative land management approaches. Dead wood has become an increasingly important conservation issue in managed forests, as awareness of its function in providing wildlife habitat and in basic ecological processes has dramatically increased over the last several decades (Laudenslayer et al., 2002). A major concern of forest managers is providing dead wood habitat for terrestrial wildlife. Wildlife in Pacific Northwest forests have evolved with disturbances that create large amounts of dead wood; so, it is not surprising that many species are closely associated with standing (snags) or down, dead wood. In general, the occurrence or abundance of one-quarter to one-third of forest-dwelling vertebrate wildlife species, is strongly associated with availability of suitable dead-wood habitat (Bunnell et al., 1999; Rose et al., 2001). In

  6. Habitat predictors of genetic diversity for two sympatric wetland-breeding amphibian species.

    PubMed

    McKee, Anna M; Maerz, John C; Smith, Lora L; Glenn, Travis C

    2017-08-01

    Population genetic diversity is widely accepted as important to the conservation and management of wildlife. However, habitat features may differentially affect evolutionary processes that facilitate population genetic diversity among sympatric species. We measured genetic diversity for two pond-breeding amphibian species (Dwarf salamanders, Eurycea quadridigitata ; and Southern Leopard frogs, Lithobates sphenocephalus ) to understand how habitat characteristics and spatial scale affect genetic diversity across a landscape. Samples were collected from wetlands on a longleaf pine reserve in Georgia. We genotyped microsatellite loci for both species to assess population structures and determine which habitat features were most closely associated with observed heterozygosity and rarefied allelic richness. Both species exhibited significant population genetic structure; however, structure in Southern Leopard frogs was driven primarily by one outlier site. Dwarf salamander allelic richness was greater at sites with less surrounding road area within 0.5 km and more wetland area within 1.0 and 2.5 km, and heterozygosity was greater at sites with more wetland area within 0.5 km. In contrast, neither measure of Southern Leopard frog genetic diversity was associated with any habitat features at any scale we evaluated. Genetic diversity in the Dwarf salamander was strongly associated with land cover variables up to 2.5 km away from breeding wetlands, and/or results suggest that minimizing roads in wetland buffers may be beneficial to the maintenance of population genetic diversity. This study suggests that patterns of genetic differentiation and genetic diversity have associations with different habitat features across different spatial scales for two syntopic pond-breeding amphibian species.

  7. Correlated factors in amphibian decline: Exotic species and habitat change in western Washington

    USGS Publications Warehouse

    Adams, Michael J.

    1999-01-01

    Amphibian declines may frequently be associated with multiple, correlated factors. In western North America, exotic species and hydrological changes are often correlated and are considered 2 of the greatest threats to freshwater systems. Bullfrog (Rana catesbeiana) introductions are frequently cited as a threat to lentic-breeding anurans native to western North America and are a suspected factor in the decline of red-legged frogs (Rana aurora) in California. Introduced fish and habitat change are cited less frequently but are equally viable hypotheses. I examined the relation among introduced species, habitat, and the distribution and abundance of red-legged frogs in western Washington. Red-legged frog occurrence in the Puget Lowlands was more closely associated with habitat structure and the presence of exotic fish than with the presence of bull-frogs. The spread of exotics is correlated with a shift toward greater permanence in wetland habitats regionally. Conservation of more ephemeral wetland habitats may have direct benefits for some native amphibians and may also reduce the threat of exotic fish and bullfrogs, both of which were associated with permanent wetlands. Research and conservation efforts for lowland anurans in the West should emphasize the complexities of multiple contributing factors to amphibian losses.

  8. Habitat Suitability Index Models: Beaver

    USGS Publications Warehouse

    Allen, Arthur W.

    1982-01-01

    Habitat preferences of the beaver (Castor canadensis) are described in this publication, which is one of a series of Habitat Suitability Index (HSI) models. Habitat use information is presented in a synthesis of the literature on the species-habitat requirements of the beaver, followed by the development of the HSI model. The model is designed to provide information for use in impact assessment and habitat management activities, and should be used in conjunction with habitat evaluation procedures previously developed by the Fish and Wildlife Service. This revised model updates the original publication dated September 1982.

  9. The influence of urban heat islands and socioeconomic factors on the spatial distribution of Aedes aegypti larval habitats.

    PubMed

    De Azevedo, Thiago S; Bourke, Brian Patrick; Piovezan, Rafael; Sallum, Maria Anice M

    2018-05-08

    We addressed the potential associations among the temporal and spatial distribution of larval habitats of Aedes (Stegomyia) aegypti, the presence of urban heat islands and socioeconomic factors. Data on larval habitats were collected in Santa Bárbara d'Oeste, São Paulo, Brazil, from 2004 to 2006, and spatial and temporal variations were analysed using a wavelet-based approach. We quantified urban heat islands by calculating surface temperatures using the results of wavelet analyses and grey level transformation from Thematic Mapper images (Landsat 5). Ae. aegypti larval habitats were geo-referenced corresponding to the wavelet analyses to test the potential association between geographical distribution of habitats and surface temperature. In an inhomogeneous spatial point process, we estimated the frequency of occurrence of larval habitats in relation to temperature. The São Paulo State Social Vulnerability Index in the municipality of Santa Barbára d'Oeste was used to test the potential association between presence of larval habitats and social vulnerability. We found abundant Ae. aegypti larval habitats in areas of higher surface temperature and social vulnerability and fewer larval habitats in areas with lower surface temperature and social vulnerability.

  10. Distributions and habitat associations of deep-water corals in Norfolk and Baltimore Canyons, Mid-Atlantic Bight, USA

    NASA Astrophysics Data System (ADS)

    Brooke, S. D.; Watts, M. W.; Heil, A. D.; Rhode, M.; Mienis, F.; Duineveld, G. C. A.; Davies, A. J.; Ross, S. W.

    2017-03-01

    A multi-disciplinary study of two major submarine canyons, Baltimore Canyon and Norfolk Canyon, off the US mid-Atlantic coast focused on the ecology and biology of canyon habitats, particularly those supporting deep-sea corals. Historical data on deep-sea corals from these canyons were sparse with less than 750 records for the mid-Atlantic region, with most being soft sediment species. This study substantially increased the number of deep-sea coral records for the target canyons and the region. Large gorgonians were the dominant structure-forming coral taxa on exposed hard substrates, but several species of scleractinians were also documented, including first observations of Lophelia pertusa in the mid-Atlantic Bight region. Coral distribution varied within and between the two canyons, with greater abundance of the octocoral Paragorgia arborea in Baltimore Canyon, and higher occurrence of stony corals in Norfolk Canyon; these observations reflect the differences in environmental conditions, particularly turbidity, between the canyons. Some species have a wide distribution (e.g., P. arborea, Primnoa resedaeformis, Anthothela grandiflora), while others are limited to certain habitat types and/or depth zones (e.g., Paramuricea placomus, L. pertusa, Solenosmilia variabilis). The distribution of a species is driven by a combination of factors, which include availability of appropriate physical structure and environmental conditions. Although the diversity of the structure-forming corals (gorgonians, branching scleractinians and large anemones) was low, many areas of both canyons supported high coral abundance and a diverse coral-associated community. The canyons provide suitable habitat for the development of deep-sea coral communities that is not readily available elsewhere on the sedimented shelf and slope of the Mid-Atlantic Bight.

  11. Aquatic habitats of Canaan Valley, West Virginia: Diversity and environmental threats

    USGS Publications Warehouse

    Snyder, C.D.; Young, J.A.; Stout, B. M.

    2006-01-01

    We conducted surveys of aquatic habitats during the spring and summer of 1995 in Canaan Valley, WV, to describe the diversity of aquatic habitats in the valley and identify issues that may threaten the viability of aquatic species. We assessed physical habitat and water chemistry of 126 ponds and 82 stream sites, and related habitat characteristics to landscape variables such as geology and terrain. Based on our analyses, we found two issues likely to affect the viability of aquatic populations in the valley. The first issue was acid rain and the extent to which it potentially limits the distribution of aquatic and semi-aquatic species, particularly in headwater portions of the watershed. We estimate that nearly 46%, or 56 kilometers of stream, had pH levels that would not support survival and reproduction of Salvelinuw fontinalis (brook trout), one of the most acid-tolerant fishes in the eastern US. The second issue was the influence of Castor canadensis (beaver) activity. In the Canaan Valley State Park portion of the valley, beaver have transformed 4.7 kilometers of stream (approximately 17% of the total) to pond habitat through their dam building. This has resulted in an increase in pond habitat, a decrease in stream habitat, and a fragmented stream network (i.e., beaver ponds dispersed among stream reaches). In addition, beaver have eliminated an undetermined amount of forested riparian area through their foraging activities. Depending on the perspective, beaver-mediated changes can be viewed as positive or negative. Increases in pond habitat may increase habitat heterogeneity with consequent increases in biological diversity. In contrast, flooding associated with beaver activity may eliminate lowland wetlands and associated species, create barriers to fish dispersal, and possibly contribute to low dissolved oxygen levels in the Blackwater River. We recommend that future management strategies for the wildlife refuge be viewed in the context of these two issues

  12. Lunar Surface Habitat Configuration Assessment: Methodology and Observations

    NASA Technical Reports Server (NTRS)

    Carpenter, Amanda

    2008-01-01

    The Lunar Habitat Configuration Assessment evaluated the major habitat approaches that were conceptually developed during the Lunar Architecture Team II Study. The objective of the configuration assessment was to identify desired features, operational considerations, and risks to derive habitat requirements. This assessment only considered operations pertaining to the lunar surface and did not consider all habitat conceptual designs developed. To examine multiple architectures, the Habitation Focus Element Team defined several adequate concepts which warranted the need for a method to assess the various configurations. The fundamental requirement designed into each concept included the functional and operational capability to support a crew of four on a six-month lunar surface mission; however, other conceptual aspects were diverse in comparison. The methodology utilized for this assessment consisted of defining figure of merits, providing relevant information, and establishing a scoring system. In summary, the assessment considered the geometric configuration of each concept to determine the complexity of unloading, handling, mobility, leveling, aligning, mating to other elements, and the accessibility to the lunar surface. In theory, the assessment was designed to derive habitat requirements, potential technology development needs and identify risks associated with living and working on the lunar surface. Although the results were more subjective opposed to objective, the assessment provided insightful observations for further assessments and trade studies of lunar surface habitats. This overall methodology and resulting observations will be describe in detail and illustrative examples will be discussed.

  13. Habitat preferences of baleen whales in a mid-latitude habitat

    NASA Astrophysics Data System (ADS)

    Prieto, Rui; Tobeña, Marta; Silva, Mónica A.

    2017-07-01

    Understanding the dynamics of baleen whale distribution is essential to predict how environmental changes can affect their ecology and, in turn, ecosystem functioning. Recent work showed that mid-latitude habitats along migratory routes may play an important role on the feeding ecology of baleen whales. This study aimed to investigate the function of a mid-latitude habitat for blue (Balaenoptera musculus), fin (Balaenoptera physalus) and sei (Balaenoptera borealis) whales occurring in sympatry during spring and summer months and to what extent their environmental niches overlap. We addressed those questions by developing environmental niche models (ENM) for each species and then making pairwise comparisons of niche overlap and relative habitat patch importance among the three species. ENMs were created using sightings from the Azorean Fisheries Observer Program from May to November, between 2004 and 2009, and a set of 18 predictor environmental variables. We then assessed monthly (April-July) overlap among ENMs using a modified Hellinger's distance metric (I). Results show that the habitat niches of blue and fin whales are strongly influenced by primary productivity and sea surface temperature and are highly dynamic both spatially and temporally due to the oceanography of the region. Niche overlap analyses show that blue and fin whale environmental niches are similar and that the suitable habitats for the two species have high degree of spatial coincidence. These results in combination suggest that this habitat may function as a mid-latitude feeding ground to both species while conditions are adequate. The sei whale model, on the other hand, did not include variables considered to be proxies for prey distribution and little environmental niche overlap was found between this species and the other two. We argue that these results suggest that the region holds little importance as a foraging habitat for the sei whale.

  14. Wildlife habitats in managed rangelands—the Great Basin of southeastern Oregon: manmade habitats.

    Treesearch

    Chris Maser; Jack Ward Thomas; Ira David Luman; Ralph. Anderson

    1979-01-01

    Manmade structures on rangelands provide specialized habitats for some species. These habitats and how they function as specialized habitat features are examined in this publication. The relationships of the wildlife of the Great Basin to such structures are detailed.

  15. ASSOCIATION AMONG INVERTEBRATES AND HABITAT INDICATORS FOR LARGE RIVERS IN THE MIDWEST

    EPA Science Inventory

    Six reaches in each of two large rivers (one each in Kentucky and Ohio) were sampled using a prototype benthic macroinvertebrate sampling technique. The intent was to better understand the relationship between large river macroinvertebrate assemblages and habitat features. This...

  16. Detroit River habitat inventory

    USGS Publications Warehouse

    Manny, Bruce A.

    2003-01-01

    This inventory complements a previous survey of habitat in Ontario waters of the Detroit River (OMNR,1993). It is a starting point for balanced and sustained use of the river for natural resource conservation and economic development. The objectives of the inventory were to: (1) locate candidate sites for protection and restoration of fish and wildlife habitat in Michigan waters of the Detroit River; (2) describe the ownership and size of each site, as well as its potential for habitat protection and restoration; and (3) subjectively assess the extent to which existing habitat along the river is productive of fish and wildlife and protected from land uses that have degraded or destroyed such habitat.

  17. Drought sensitivity predicts habitat size sensitivity in an aquatic ecosystem.

    PubMed

    Amundrud, Sarah L; Srivastava, Diane S

    2015-07-01

    Species and trophic richness often increase with habitat size. Although many ecological processes have been evoked to explain both patterns, the environmental stress associated with small habitats has rarely been considered. We propose that larger habitats may be species rich simply because their environmental conditions are within the fundamental niche of more species; larger habitats may also have more trophic levels if traits of predators render them vulnerable to environmental stress. We test this hypothesis using the aquatic insect larvae in water-filled bromeliads. In bromeliads, the probability of desiccation is greatest in small plants. For the 10 most common bromeliad insect taxa, we ask whether differences in drought tolerance and regional abundances between taxa predict community and trophic composition over a gradient of bromeliad size. First, we used bromeliad survey data to calculate the mean habitat size of occurrence of each taxon. Comparing the observed mean habitat size of occurrence to that expected from random species assembly based on differences in their regional abundances allowed us to obtain habitat size sensitivity indices (as Z scores) for the various insect taxa. Second, we obtained drought sensitivity indices by subjecting individual insects to drought and measuring the effects on relative growth rates in a mesocosm experiment. We found that drought sensitivity strongly, predicts habitat size sensitivity in bromeliad insects. However, an increase in trophic richness with habitat size could not be explained by an increased sensitivity of predators to drought, but rather by sampling effects, as predators were rare compared to lower trophic levels. This finding suggests that physiological tolerance to environmental stress can be relevant in explaining the universal increase in species with habitat size.

  18. Clackamas/Hood River Habitat Enhancement Program, 1987 Annual Report.

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

    MacDonald, Ken; Cain, Thomas C.; Heller, David A.

    1988-03-01

    a variety of species and age group: of salmon and trout can rear. It also results in the sorting of gravel, rubble, and boulders being transported downstream, creating high quality spawning and rearing habitats, and food producing areas. In 1987, a total of 11.0 miles of stream were treated; 334 log structures (Including: ''deflector'', ''digger'', ''sill'', and ''cover'' logs) and 141 boulder structures (including: single boulder placement, ''berms'', ''alcoves'', and ''clusters'') were completed to meet habitat improvement objectives. In addition to these direct habitat improvement activities, BPA and the Forest Service financed a number of project and program assessment activities that have improved the efficiency and effectiveness of the Forest's fisheries management program. Notable findings relate to the durability of habitat improvement structures, the associated changes in physical habitat, and biological response to the improvement activities. A discussion of the 1987 habitat monitoring and evaluation program results can be found in the supplemental document, Appendix: Monitoring and Evaluation of Mt. Hood National Forest Stream Habitat Improvement and Rehabilitation Projects: 1987 Annual Report (Forsgren, Heller, and Ober, 1988).« less

  19. Faunal communities and habitat characteristics of the Big Bend seagrass meadows, 2009-2010.

    EPA Science Inventory

    Seagrass meadows are important habitats that serve as nursery, feeding, and sheltering grounds for many marine species. In addition to the ecosystem functions and services they provide, seagrass habitats and associated fauna are commonly observed to have naturally high levels of...

  20. Wetland habitats for wildlife of the Chesapeake Bay

    USGS Publications Warehouse

    Perry, M.C.; Majumdar, S.K.; Miller, E.W.; Brenner, Fred J.

    1998-01-01

    The wetlands of Chesapeake Bay have provided the vital habitats that have sustained the impressive wildlife populations that have brought international fame to the Bay. As these wetland habitats decrease in quantity and quality we will continue to see the decline in the wildlife populations that started when European settlers first came to this continent. These declines have accelerated significantly in this century. As the human population continues to increase in the Bay watershed, one can expect that wetland habitats will continue to decline, resulting in declines in species diversity and population numbers. Although federal, state, and local governments are striving for 'no net loss' of wetlands, the results to date are not encouraging. It is unrealistic to believe that human populations and associated development can continue to increase and not adversely affect the wetland resources of the Bay. Restrictions on human population growth in the Chesapeake area is clearly the best way to protect wetland habitats and the wildlife that are dependent on these habitats. In addition, there should be more aggressive approaches to protect wetland habitats from continued perturbations from humans. More sanctuary areas should be created and there should be greater use of enhancement and management techniques that will benefit the full complement of species that potentially exist in these wetlands. The present trend in wetland loss can be expected to continue as human populations increase with resultant increases in roads, shopping malls, and housing developments. Creation of habitat for mitigation of these losses will not result in 'no net loss'. More innovative approaches should be employed to reverse the long-term trend in wetland loss by humans.

  1. Coefficients of productivity for Yellowstone's grizzly bear habitat

    USGS Publications Warehouse

    Mattson, David John; Barber, Kim; Maw, Ralene; Renkin, Roy

    2004-01-01

    This report describes methods for calculating coefficients used to depict habitat productivity for grizzly bears in the Yellowstone ecosystem. Calculations based on these coefficients are used in the Yellowstone Grizzly Bear Cumulative Effects Model to map the distribution of habitat productivity and account for the impacts of human facilities. The coefficients of habitat productivity incorporate detailed information that was collected over a 20-year period (1977-96) on the foraging behavior of Yellowstone's bears and include records of what bears were feeding on, when and where they fed, the extent of that feeding activity, and relative measures of the quantity consumed. The coefficients also incorporate information, collected primarily from 1986 to 1992, on the nutrient content of foods that were consumed, their digestibility, characteristic bite sizes, and the energy required to extract and handle each food. Coefficients were calculated for different time periods and different habitat types, specific to different parts of the Yellowstone ecosystem. Stratifications included four seasons of bear activity (spring, estrus, early hyperphagia, late hyperphagia), years when ungulate carrion and whitebark pine seed crops were abundant versus not, areas adjacent to (< 100 m) or far away from forest/nonforest edges, and areas inside or outside of ungulate winter ranges. Densities of bear activity in each region, habitat type, and time period were incorporated into calculations, controlling for the effects of proximity to human facilities. The coefficients described in this report and associated estimates of grizzly bear habitat productivity are unique among many efforts to model the conditions of bear habitat because calculations include information on energetics derived from the observed behavior of radio-marked bears.

  2. Habitat Suitability Index Models: Veery

    USGS Publications Warehouse

    Sousa, Patrick J.

    1982-01-01

    Habitat preferences and species characteristics of the veery (Catharus fuscesens) are described in this publication. It is one of a series of Habitat Suitability Index (HSI) models and was developed through an analysis of available scientific data on the habitat requirements of the veery. Habitat use information is presented in a review of the literature, followed by the development of an HSI model. The model is presented in three formats: graphic; word; and mathematical. Suitability index graphs quantify the species-habitat relationship. These data are synthesized into a model designed to provide information for use in impact assessment and habitat management.

  3. Spatial variability of Chinook salmon spawning distribution and habitat preferences

    USGS Publications Warehouse

    Cram, Jeremy M.; Torgersen, Christian E.; Klett, Ryan S.; Pess, George R.; May, Darran; Pearsons, Todd N.; Dittman, Andrew H.

    2017-01-01

    We investigated physical habitat conditions associated with the spawning sites of Chinook Salmon Oncorhynchus tshawytscha and the interannual consistency of spawning distribution across multiple spatial scales using a combination of spatially continuous and discrete sampling methods. We conducted a census of aquatic habitat in 76 km of the upper main-stem Yakima River in Washington and evaluated spawning site distribution using redd survey data from 2004 to 2008. Interannual reoccupation of spawning areas was high, ranging from an average Pearson’s correlation of 0.62 to 0.98 in channel subunits and 10-km reaches, respectively. Annual variance in the interannual correlation of spawning distribution was highest in channel units and subunits, but it was low at reach scales. In 13 of 15 models developed for individual years (2004–2008) and reach lengths (800 m, 3 km, 6 km), stream power and depth were the primary predictors of redd abundance. Multiple channels and overhead cover were patchy but were important secondary and tertiary predictors of reach-scale spawning site selection. Within channel units and subunits, pool tails and thermal variability, which may be associated with hyporheic exchange, were important predictors of spawning. We identified spawning habitat preferences within reaches and channel units that are relevant for salmonid habitat restoration planning. We also identified a threshold (i.e., 2-km reaches) beyond which interannual spawning distribution was markedly consistent, which may be informative for prioritizing habitat restoration or conservation. Management actions may be improved through enhanced understanding of spawning habitat preferences and the consistency with which Chinook Salmon reoccupy spawning areas at different spatial scales.

  4. Eder Acquisition 2007 Habitat Evaluation Procedures Report.

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

    Ashley, Paul R.

    A habitat evaluation procedures (HEP) analysis was conducted on the Eder acquisition in July 2007 to determine how many protection habitat units to credit Bonneville Power Administration (BPA) for providing funds to acquire the project site as partial mitigation for habitat losses associated with construction of Grand Coulee and Chief Joseph Dams. Baseline HEP surveys generated 3,857.64 habitat units or 1.16 HUs per acre. HEP surveys also served to document general habitat conditions. Survey results indicated that the herbaceous plant community lacked forbs species, which may be due to both livestock grazing and the late timing of the surveys. Moreover,more » the herbaceous plant community lacked structure based on lower than expected visual obstruction readings (VOR); likely a direct result of livestock impacts. In addition, introduced herbaceous vegetation including cultivated pasture grasses, e.g. crested wheatgrass and/or invader species such as cheatgrass and mustard, were present on most areas surveyed. The shrub element within the shrubsteppe cover type was generally a mosaic of moderate to dense shrubby areas interspersed with open grassland communities while the 'steppe' component was almost entirely devoid of shrubs. Riparian shrub and forest areas were somewhat stressed by livestock. Moreover, shrub and tree communities along the lower reaches of Nine Mile Creek suffered from lack of water due to the previous landowners 'piping' water out of the stream channel.« less

  5. Habitat Suitability Index Models: Pronghorn

    USGS Publications Warehouse

    Allen, Arthur W.; Cook, John G.; Armbruster, Michael J.

    1984-01-01

    This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the pronghorn (Antilocapra americana) are synthesized. These data are subsequently used to develop Habitat Suitability Index (HSI) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

  6. Habitat Suitability Index Models: Muskellunge

    USGS Publications Warehouse

    Cook, Mark F.; Solomon, R. Charles

    1987-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the muskellunge (Esox masquinongy Mitchell). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  7. Habitat selection by postbreeding female diving ducks: Influence of habitat attributes and conspecifics

    USGS Publications Warehouse

    Austin, Jane E.; O'Neil, Shawn T.; Warren, Jeffrey M.

    2017-01-01

    Habitat selection studies of postbreeding waterfowl have rarely focused on within-wetland attributes such as water depth, escape cover, and food availability. Flightless waterfowl must balance habitat selection between avoiding predation risks and feeding. Reproductively successful female ducks face the greatest challenges because they begin the definitive prebasic molt at or near the end of brood rearing, when their body condition is at a low point. We assessed the relative importance of habitat attributes and group effects in habitat selection by postbreeding female lesser scaup Aythya affinis on a 2332-ha montane wetland complex during the peak flightless period (August) over seven years. Hypothesis-based habitat attributes included percent open water, open water:emergent edge density, water depth, percent flooded bare substrate, fetch (distance wind can travel unobstructed), group size, and several interactions representing functional responses to interannual variation in water levels. Surveys of uniquely marked females were conducted within randomly ordered survey blocks. We fitted two-part generalized linear mixed-effects models to counts of marked females within survey blocks, which allowed us to relate habitat attributes to relative probability of occurrence and, given the presence of a marked female, abundance of marked individuals. Postbreeding female scaup selected areas with water depths > 40 cm, large open areas, and intermediate edge densities but showed no relation to flooded bare substrate, suggesting their habitat preferences were more influenced by avoiding predation risks and disturbances than in meeting foraging needs. Grouping behavior by postbreeding scaup suggests habitat selection is influenced in part by behavioral components and/or social information, conferring energetic and survival benefits (predation and disturbance risks) but potentially also contributing to competition for food resources. This study demonstrates the importance of

  8. Fuels planning: science synthesis and integration; environmental consequences fact sheet 15: The Wildlife Habitat Response Model

    Treesearch

    David Pilliod

    2005-01-01

    The Wildlife Habitat Response Model (WHRM) is a Web-based computer tool for evaluating the potential effects of fuel-reduction projects on terrestrial wildlife habitats. It uses species-habitat associations in ponderosa pine (Pinus ponderosa), dry-type Douglas-fir (Pseudotsuga menziesii), lodgepole pine (Pinus...

  9. Interconnected microbiomes and resistomes in low-income human habitats

    PubMed Central

    Pehrsson, Erica C.; Tsukayama, Pablo; Patel, Sanket; Mejía-Bautista, Melissa; Sosa-Soto, Giordano; Navarrete, Karla M.; Calderon, Maritza; Cabrera, Lilia; Hoyos-Arango, William; Bertoli, M. Teresita; Berg, Douglas E.; Gilman, Robert H.; Dantas, Gautam

    2016-01-01

    Summary Antibiotic-resistant infections annually claim hundreds of thousands of lives worldwide. This problem is exacerbated by resistance gene exchange between pathogens and benign microbes from diverse habitats. Mapping resistance gene dissemination between humans and their environment is a public health priority. We characterized the bacterial community structure and resistance exchange networks of hundreds of interconnected human fecal and environmental samples from two low-income Latin American communities. We found that resistomes across habitats are generally structured by bacterial phylogeny along ecological gradients, but identified key resistance genes that cross habitat boundaries and determined their association with mobile genetic elements. We also assessed the effectiveness of widely-used excreta management strategies in reducing fecal bacteria and resistance genes in these settings representative of low- and middle-income countries. Our results lay the foundation for quantitative risk assessment and surveillance of resistance dissemination across interconnected habitats in settings representing over two-thirds of the world’s population. PMID:27172044

  10. Parallel Evolution of Larval Feeding Behavior, Morphology, and Habitat in the Snail-Kiling fly Genus Tetanocera

    NASA Astrophysics Data System (ADS)

    Chapman, E. G.; Foote, B. A.; Malukiewicz, J.; Hoeh, W. R.

    2005-05-01

    Sciomyzid larvae (Diptera: Acalyptratae) display a wide range of feeding behaviors, typically preying on a wide variety of gastropods. The genus Tetanocera is particularly interesting because its species occupy five larval feeding groups with each species' larvae living in one of two habitat types (aquatic or terrestrial). We constructed a molecular phylogeny for Tetanocera, estimated evolutionary transitions in larval feeding behaviors and habitats that occurred during Tetanocera phylogenesis, and investigated potential correlations among larval habitat and morphological characteristics. Approximately 3800 base pairs (both mitochondrial and nuclear) of sequence data were used to build the phylogeny. Larval feeding groups and habitat type were mapped onto the phylogeny and pair-wise comparisons were used to evaluate potential associations between habitat and morphology. Feeding and habitat groups within Tetanocera were usually not monophyletic and it was estimated that Tetanocera lineages made at least three independent aquatic to terrestrial transitions. These parallel habitat shifts were typically accompanied by parallel character state changes in four morphological characteristics (larval color and three posterior spiracular disc characters). These larval habitat-morphology associations were statistically significant and consistent with the action of natural selection in facilitating the morphological changes that occurred during aquatic to terrestrial habitat transitions in Tetanocera.

  11. The relationships of seabird assemblages to physical habitat features in Pacific equatorial waters during spring 1984-1991

    USGS Publications Warehouse

    Ribic, C.A.; Ainley, D.G.

    1997-01-01

    The association of seabird species groups with physical habitat was investigated in the eastern tropical Pacific Ocean, far from any breeding colonies. This avoided birds that commute between colony and feeding habitat, behaviour that confuses associations with specific water types and current systems. Seabirds were counted on duplicate tracks in the eastern tropical Pacific each spring from 1984-1991. On each cruise, seabird habitat was measured on the basis of six factors and focused on three species groups: (A) black-winged petrel and white-winged petrel, (B) Juan Fernandez petrel, wedge-tailed shearwater, and sooty tern, and (C) Leach's storm-petrel and wedge-rumped storm-petrel. Group A was associated with the South Equatorial Current, particularly in cooler waters (median of 26.4??C); both petrel species followed this assemblage association with current. Group B was associated with areas characterized by deep thermoclines (median of 60 m) and low salinities (median of 34.33). Within Group B, two of the three species' responses were consistent with the group pattern; Juan Fernandez petrel differed by occurring more often where thermocline slopes were steep (median of 9.8 deg C m-1). Group C was not associated with any physical habitat variable. This was due to species in the group being associated with different habitats: Leach's storm-petrel with the tropical and equatorial surface water masses and wedge-rumped storm-petrel with waters having shallower thermocline depths (median of 22 m). Overall, two of the three assemblages appeared to be associated with physical habitat during spring with consistency among the species in the group. An association with thermocline depth may indicate that productivity was an important predictor of assemblage presence.

  12. Lemur habitat and dental senescence in Ranomafana National Park, Madagascar.

    PubMed

    King, Stephen J; Boyer, Doug M; Tecot, Stacey; Strait, Suzanne G; Zohdy, Sarah; Blanco, Marina B; Wright, Patricia C; Jernvall, Jukka

    2012-06-01

    Not only can teeth provide clues about diet, but they also can be indicators of habitat quality. Conspecific groups living in different habitats with different kinds of foods may exhibit different rates of dental attrition because their teeth are less well adapted to some foods than to others. Ecological disequilibrium describes the situation in which animals live in habitats to which they are relatively poorly adapted. We test whether dental senescence, the wear-related decrease in dental functionality that is associated with decreased survival of infants born to older Propithecus edwardsi females, can be explained by ecological disequilibrium. Specifically, we compare the rates of dental wear in sifaka groups living in nearby habitats that differ in the degree of anthropogenically induced disturbance. We hypothesize that sifakas living in disturbed areas have an unusual rate of tooth wear compared to those living in a more pristine area, and that dental senescence is a consequence of an atypically high wear rate in a degraded habitat. To test whether habitat quality affects tooth wear more generally, we compare rates of use-wear in two subsets of Microcebus rufus living in either relatively undisturbed or disturbed habitats. Contrary to our predictions, we did not detect different rates of tooth wear in disturbed versus undisturbed habitats for either species and consider that reproductively detrimental dental senescence in P. edwardsi females is unlikely to be a pathological consequence of ecological disequilibrium. Copyright © 2012 Wiley Periodicals, Inc.

  13. Habitat fragmentation in coastal southern California disrupts genetic connectivity in the cactus wren (Campylorhynchus brunneicapillus).

    PubMed

    Barr, Kelly R; Kus, Barbara E; Preston, Kristine L; Howell, Scarlett; Perkins, Emily; Vandergast, Amy G

    2015-05-01

    Achieving long-term persistence of species in urbanized landscapes requires characterizing population genetic structure to understand and manage the effects of anthropogenic disturbance on connectivity. Urbanization over the past century in coastal southern California has caused both precipitous loss of coastal sage scrub habitat and declines in populations of the cactus wren (Campylorhynchus brunneicapillus). Using 22 microsatellite loci, we found that remnant cactus wren aggregations in coastal southern California comprised 20 populations based on strict exact tests for population differentiation, and 12 genetic clusters with hierarchical Bayesian clustering analyses. Genetic structure patterns largely mirrored underlying habitat availability, with cluster and population boundaries coinciding with fragmentation caused primarily by urbanization. Using a habitat model we developed, we detected stronger associations between habitat-based distances and genetic distances than Euclidean geographic distance. Within populations, we detected a positive association between available local habitat and allelic richness and a negative association with relatedness. Isolation-by-distance patterns varied over the study area, which we attribute to temporal differences in anthropogenic landscape development. We also found that genetic bottleneck signals were associated with wildfire frequency. These results indicate that habitat fragmentation and alterations have reduced genetic connectivity and diversity of cactus wren populations in coastal southern California. Management efforts focused on improving connectivity among remaining populations may help to ensure population persistence. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  14. Plausible Martian Habitats

    NASA Image and Video Library

    2009-10-13

    Unfrozen brine in cryopegs and fracture networks provides habitats for the survival and growth of organisms both within and under frozen rocky materials on Earth and, by analogy, could provide habitats on Mars.

  15. Inter-annual variability of North Sea plaice spawning habitat

    NASA Astrophysics Data System (ADS)

    Loots, C.; Vaz, S.; Koubbi, P.; Planque, B.; Coppin, F.; Verin, Y.

    2010-11-01

    Potential spawning habitat is defined as the area where environmental conditions are suitable for spawning to occur. Spawning adult data from the first quarter (January-March) of the International Bottom Trawl Survey have been used to study the inter-annual variability of the potential spawning habitat of North Sea plaice from 1980 to 2007. Generalised additive models (GAM) were used to create a model that related five environmental variables (depth, bottom temperature and salinity, seabed stress and sediment type) to presence-absence and abundance of spawning adults. Then, the habitat model was applied each year from 1970 to 2007 to predict inter-annual variability of the potential spawning habitat. Predicted responses obtained by GAM for each year were mapped using kriging. A hierarchical classification associated with a correspondence analysis was performed to cluster spawning suitable areas and to determine how they evolved across years. The potential spawning habitat was consistent with historical spawning ground locations described in the literature from eggs surveys. It was also found that the potential spawning habitat varied across years. Suitable areas were located in the southern part of the North Sea and along the eastern coast of England and Scotland in the eighties; they expanded further north from the nineties. Annual survey distributions did not show such northward expansion and remained located in the southern North Sea. This suggests that this species' actual spatial distribution remains stable against changing environmental conditions, and that the potential spawning habitat is not fully occupied. Changes in environmental conditions appear to remain within plaice environmental ranges, meaning that other factors may control the spatial distribution of plaice spawning habitat.

  16. Habitat Suitability Index Models: Marten

    USGS Publications Warehouse

    Allen, Arthur W.

    1982-01-01

    Habitat preferences and species characteristics of the pine marten (Martes americana) are described in this publication. It is one of a series of Habitat Suitability Index (HSI) models and was developed through an analysis of available scientific data on the species-habitat requirements of the pine marten. Habitat use information is presented in a review of the literature, followed by the development of a HSI model. The model is presented in three formats: graphic, word and mathematical. Suitability index graphs quantify the species-habitat relationship. These data are then synthesized into a model which is designed to provide information for use in impact assessment and habitat management activities.

  17. Using forest inventory data to assess fisher resting habitat suitability in California.

    Treesearch

    William J. Zielinski; Richard L. Truex; Jeffrey R. Dunk; Tom Gaman

    2006-01-01

    The fisher (Martes pennanti) is a forest-dwelling carnivore whose current distribution and association with late-seral forest conditions make it vulnerable to stand-altering human activities or natural disturbances. Fishers select a variety of structures for daily resting bouts. These habitat elements, together with foraging and reproductive (denning) habitat,...

  18. Landscape habitat suitability index software

    Treesearch

    William D. Dijak; Chadwick D. Rittenhouse; Michael A. Larson; Frank R. III Thompson; Joshua J. Millspaugh

    2007-01-01

    Habitat suitability index (HSI) models are traditionally used to evaluate habitat quality for wildlife at a local scale. Rarely have such models incorporated spatial relationships of habitat components. We introduce Landscape HSImodels, a new Microsoft Windowst (Microsoft, Redmond, WA)-based program that incorporates local habitat as well as landscape-scale attributes...

  19. Adjacent Habitat Influence on Stink Bug (Hemiptera: Pentatomidae) Densities and the Associated Damage at Field Corn and Soybean Edges

    PubMed Central

    Venugopal, P. Dilip; Coffey, Peter L.; Dively, Galen P.; Lamp, William O.

    2014-01-01

    The local dispersal of polyphagous, mobile insects within agricultural systems impacts pest management. In the mid-Atlantic region of the United States, stink bugs, especially the invasive Halyomorpha halys (Stål 1855), contribute to economic losses across a range of cropping systems. Here, we characterized the density of stink bugs along the field edges of field corn and soybean at different study sites. Specifically, we examined the influence of adjacent managed and natural habitats on the density of stink bugs in corn and soybean fields at different distances along transects from the field edge. We also quantified damage to corn grain, and to soybean pods and seeds, and measured yield in relation to the observed stink bug densities at different distances from field edge. Highest density of stink bugs was limited to the edge of both corn and soybean fields. Fields adjacent to wooded, crop and building habitats harbored higher densities of stink bugs than those adjacent to open habitats. Damage to corn kernels and to soybean pods and seeds increased with stink bug density in plots and was highest at the field edges. Stink bug density was also negatively associated with yield per plant in soybean. The spatial pattern of stink bugs in both corn and soybeans, with significant edge effects, suggests the use of pest management strategies for crop placement in the landscape, as well as spatially targeted pest suppression within fields. PMID:25295593

  20. Adjacent habitat influence on stink bug (Hemiptera: Pentatomidae) densities and the associated damage at field corn and soybean edges.

    PubMed

    Venugopal, P Dilip; Coffey, Peter L; Dively, Galen P; Lamp, William O

    2014-01-01

    The local dispersal of polyphagous, mobile insects within agricultural systems impacts pest management. In the mid-Atlantic region of the United States, stink bugs, especially the invasive Halyomorpha halys (Stål 1855), contribute to economic losses across a range of cropping systems. Here, we characterized the density of stink bugs along the field edges of field corn and soybean at different study sites. Specifically, we examined the influence of adjacent managed and natural habitats on the density of stink bugs in corn and soybean fields at different distances along transects from the field edge. We also quantified damage to corn grain, and to soybean pods and seeds, and measured yield in relation to the observed stink bug densities at different distances from field edge. Highest density of stink bugs was limited to the edge of both corn and soybean fields. Fields adjacent to wooded, crop and building habitats harbored higher densities of stink bugs than those adjacent to open habitats. Damage to corn kernels and to soybean pods and seeds increased with stink bug density in plots and was highest at the field edges. Stink bug density was also negatively associated with yield per plant in soybean. The spatial pattern of stink bugs in both corn and soybeans, with significant edge effects, suggests the use of pest management strategies for crop placement in the landscape, as well as spatially targeted pest suppression within fields.

  1. Wetlands reserve program: a partnership to restore wetlands and associated habitat

    Treesearch

    Randall L. Gray

    2005-01-01

    The 1990 Farm Bill created the Wetlands Reserve Program (WRP) to restore and protect wetland, which as of 2002 has enrolled over 1.4 million acres of wetland and upland habitat in 49 states and Puerto Rico. The program is administered by the U. S. Department of Agriculture Natural Resource Conservation Service and delivered in cooperation with many partners from the...

  2. Habitat Selectivity and Reliance on Live Corals for Indo-Pacific Hawkfishes (Family: Cirrhitidae).

    PubMed

    Coker, Darren J; Hoey, Andrew S; Wilson, Shaun K; Depczynski, Martial; Graham, Nicholas A J; Hobbs, Jean-Paul A; Holmes, Thomas H; Pratchett, Morgan S

    2015-01-01

    Hawkfishes (family: Cirrhitidae) are small conspicuous reef predators that commonly perch on, or shelter within, the branches of coral colonies. This study examined habitat associations of hawkfishes, and explicitly tested whether hawkfishes associate with specific types of live coral. Live coral use and habitat selectivity of hawkfishes was explored at six locations from Chagos in the central Indian Ocean extending east to Fiji in the Pacific Ocean. A total of 529 hawkfishes from seven species were recorded across all locations with 63% of individuals observed perching on, or sheltering within, live coral colonies. Five species (all except Cirrhitus pinnulatus and Cirrhitichthys oxycephalus) associated with live coral habitats. Cirrhitichthys falco selected for species of Pocillopora while Paracirrhites arcatus and P. forsteri selected for both Pocillopora and Acropora, revealing that these habitats are used disproportionately more than expected based on the local cover of these coral genera. Habitat selection was consistent across geographic locations, and species of Pocillopora were the most frequently used and most consistently selected even though this coral genus never comprised more than 6% of the total coral cover at any of the locations. Across locations, Paracirrhites arcatus and P. forsteri were the most abundant species and variation in their abundance corresponded with local patterns of live coral cover and abundance of Pocilloporid corals, respectively. These findings demonstrate the link between small predatory fishes and live coral habitats adding to the growing body of literature highlighting that live corals (especially erect branching corals) are critically important for sustaining high abundance and diversity of fishes on coral reefs.

  3. Tradeoffs between homing and habitat quality for spawning site selection by hatchery-origin Chinook salmon

    USGS Publications Warehouse

    Cram, Jeremy M.; Torgersen, Christian E.; Klett, Ryan S.; Pess, George R.; May, Darran; Pearsons, Todd N.; Dittman, Andrew H.

    2013-01-01

    Spawning site selection by female salmon is based on complex and poorly understood tradeoffs between the homing instinct and the availability of appropriate habitat for successful reproduction. Previous studies have shown that hatchery-origin Chinook salmon (Oncorhynchus tshawytscha) released from different acclimation sites return with varying degrees of fidelity to these areas. To investigate the possibility that homing fidelity is associated with aquatic habitat conditions, we quantified physical habitat throughout 165 km in the upper Yakima River basin (Washington, USA) and mapped redd and carcass locations from 2004 to 2008. Principal components analysis identified differences in substrate, cover, stream width, and gradient among reaches surrounding acclimation sites, and canonical correspondence analysis revealed that these differences in habitat characteristics were associated with spatial patterns of spawning (p < 0.01). These analyses indicated that female salmon may forego spawning near their acclimation area if the surrounding habitat is unsuitable. Evaluating the spatial context of acclimation areas in relation to surrounding habitat may provide essential information for effectively managing supplementation programs and prioritizing restoration actions.

  4. Habitat Suitability Index Models: Yellow perch

    USGS Publications Warehouse

    Krieger, Douglas A.; Terrell, James W.; Nelson, Patrick C.

    1983-01-01

    A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for yellow perch (Perca flavescens). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for riverine, lacustrine, and palustrine habitat in the 48 contiguous United States. Habitat Suitability Indexes (HSI's) are designed for use with the Habitat Evaluation Procedures developed by the U.S. Fish and Wildlife Service. Also included are discussions of Suitability Index (SI) curves as used in the Instream Flow Incremental Methodology (IFIM) and SI curves available for an IFIM analysis of yellow perch habitat.

  5. Smartphone technologies and Bayesian networks to assess shorebird habitat selection

    USGS Publications Warehouse

    Zeigler, Sara; Thieler, E. Robert; Gutierrez, Ben; Plant, Nathaniel G.; Hines, Megan K.; Fraser, James D.; Catlin, Daniel H.; Karpanty, Sarah M.

    2017-01-01

    Understanding patterns of habitat selection across a species’ geographic distribution can be critical for adequately managing populations and planning for habitat loss and related threats. However, studies of habitat selection can be time consuming and expensive over broad spatial scales, and a lack of standardized monitoring targets or methods can impede the generalization of site-based studies. Our objective was to collaborate with natural resource managers to define available nesting habitat for piping plovers (Charadrius melodus) throughout their U.S. Atlantic coast distribution from Maine to North Carolina, with a goal of providing science that could inform habitat management in response to sea-level rise. We characterized a data collection and analysis approach as being effective if it provided low-cost collection of standardized habitat-selection data across the species’ breeding range within 1–2 nesting seasons and accurate nesting location predictions. In the method developed, >30 managers and conservation practitioners from government agencies and private organizations used a smartphone application, “iPlover,” to collect data on landcover characteristics at piping plover nest locations and random points on 83 beaches and barrier islands in 2014 and 2015. We analyzed these data with a Bayesian network that predicted the probability a specific combination of landcover variables would be associated with a nesting site. Although we focused on a shorebird, our approach can be modified for other taxa. Results showed that the Bayesian network performed well in predicting habitat availability and confirmed predicted habitat preferences across the Atlantic coast breeding range of the piping plover. We used the Bayesian network to map areas with a high probability of containing nesting habitat on the Rockaway Peninsula in New York, USA, as an example application. Our approach facilitated the collation of evidence-based information on habitat selection

  6. Habitat suitability index models: Black crappie

    USGS Publications Warehouse

    Edwards, Elizabeth A.; Krieger, Douglas A.; Bacteller, Mary; Maughan, O. Eugene

    1982-01-01

    Characteristics and habitat requirements of the black crappie (Pomoxis nigromaculatus) are described in a review of Habitat Suitability Index models. This is one in a series of publications to provide information on the habitat requirements of selected fish and wildlife species. Numerous literature sources have been consulted in an effort to consolidate scientific data on species-habitat relationships. These data have subsequently been synthesized into explicit Habitat Suitability Index (HSI) models. The models are based on suitability indices indicating habitat preferences. Indices have been formulated for variables found to affect the life cycle and survival of each species. Habitat Suitability Index (HSI) models are designed to provide information for use in impact assessment and habitat management activities. The HSI technique is a corollary to the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures.

  7. Migratory bird habitat in relation to tile drainage and poorly drained hydrologic soil groups

    USGS Publications Warehouse

    Kastner, Brandi; Christensen, Victoria G.; Williamson, Tanja N.; Sanocki, Chris A.

    2016-01-01

    The Prairie Pothole Region (PPR) is home to more than 50% of the migratory waterfowl in North America. Although the PPR provides an abundance of temporary and permanent wetlands for nesting and feeding, increases in commodity prices and agricultural drainage practices have led to a trend of wetland drainage. The Northern Shoveler is a migratory dabbling duck species that uses wetland habitats and cultivated croplands in the PPR. Richland County in North Dakota and Roberts County in South Dakota have an abundance of wetlands and croplands and were chosen as the study areas for this research to assess the wetland size and cultivated cropland in relation to hydrologic soil groups for the Northern Shoveler habitat. This study used geographic information system data to analyze Northern Shoveler habitats in association with Natural Resource Conservation Service soil data. Habitats, which are spatially associated with certain hydrologic soil groups, may be at risk of artificial drainage installations because of their proximity to cultivated croplands and soil lacking in natural drainage that may become wet or inundated. Findings indicate that most wetlands that are part of Northern Shoveler habitats were within or adjacent to cultivated croplands. The results also revealed soil hydrologic groups with high runoff potential and low water transmission rates account for most of the soil within the Northern Shoveler‘s wetland and cropland habitats. Habitats near agriculture with high runoff potential are likely to be drained and this has the potential of reducing Northern Shoveler habitat.

  8. Habitat Evaluation Procedures (HEP) Report : Rainwater Wildlife Area, 1998-2001 Technical Report.

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

    Childs, Allen

    The 8,768 acre Rainwater Wildlife Area was acquired in September 1998 by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) through an agreement with Bonneville Power Administration (BPA) to partially offset habitat losses associated with construction of the John Day and McNary hydroelectric facilities on the mainstem Columbia River. U.S. Fish and Wildlife Service (USFWS) Habitat Evaluation Procedures (HEP) were used to determine the number of habitat units credited to BPA for acquired lands. Upland and riparian forest, upland and riparian shrub, and grassland rover types are evaluated in this study. Targeted wildlife species include downy woodpecker (Picoides pubescens),more » black-capped chickadee (Parus atricopillus), blue grouse (Dendragapus obscurus), great blue heron (Ardea herodias), yellow warbler (Dendroica petechia), mink (Mustela vison), and Western meadowlark (Sturnella neglects). Habitat surveys were conducted in 1998 and 1999 in accordance with published HEP protocols and included 65,300, 594m{sup 2} plots, and 112 one-tenth-acre plots. Between 153.3 and 7,187.46 acres were evaluated for each target wildlife mitigation species. Derived habitat suitability indices were multiplied by corresponding cover-type acreages to determine the number of habitat units for each species. The total baseline habitat units credited to BPA for the Rainwater Wildlife Area and its seven target species is 5,185.3 habitat units. Factors limiting habitat suitability are related to the direct, indirect, and cumulative effects of past livestock grazing, road construction, and timber harvest which have simplified the structure, composition, and diversity of native plant communities. Alternatives for protecting and improving habitat suitability include exclusion of livestock grazing, road de-commissioning/obliteration, reforestation and thinning, control of competing and unwanted vegetation (including noxious weeds), reestablishing displaced or reduced native

  9. Effects of tide cycles on habitat selection and habitat partitioning by migrating shorebirds

    USGS Publications Warehouse

    Burger, J.; Howe, M.A.; Hahn, D.C.; Chase, J.

    1977-01-01

    We studied assemblages of feeding shorebirds in three intertidal habitats on the coast of New Jersey during August to document how species segregate spatially both among and within habitats and to determine the effects of tidal cycles on these patterns. The habitats were a sandy beach facing the ocean proper (outer beach), a sandy beach on the mainland side of a barrier island (inner beach), and a small mudflat adjacent to a Spartina alterniflora salt marsh. We were able to identify several microhabitats on the outer beach and mudflat. Most species fed in more than one habitat, but only two, Charadrius semipalmatus and Calidris canutus, used all three habitats regularly. Within habitats, most species exhibited strong preferences for the wettest areas, but we found differences among species in degrees of preference. The least amount of partitioning occurred on the inner beach, where birds crowded into a small zone near the water's edge and had frequent agonistic encounters suggesting intense competition. Shorebird feeding activity was partly a function of tide time: each habitat had a characteristic temporal pattern of use by shorebirds related to tide time rather than diel time; within habitats, we found species-characteristic feeding activity rhythms that were also a function of tide time. Feeding by most species peaked during the first 2 hours after low tide on the outer beach and mudflat. The results are discussed in terms of feeding strategies and interspecific competition.

  10. Urban Areas. Habitat Pac.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    The materials in this educational packet are designed for use with students in grades 4 through 7. They consist of an overview, teaching guides and student data sheets for three activities, and a poster. The overview discusses the city as an ecosystem, changing urban habitats, urban wildlife habitats, values of wildlife, habitat management, and…

  11. Stopover habitat: management implications and guidelines

    Treesearch

    Frank R. Moore; Sidney A. Gauthreaux; Paul Kerlinger; Ted R. Simons

    1993-01-01

    If persistence of migrant populations depends on the ability to find favorable conditions for survival throughout the annual cycle, factors associated with the en-route ecology of migrants must figure in any analysis of population change and in development of a comprehensive conservation "strategy." We view en-route habitat selection as a hierarchical process...

  12. Principles of wildlife habitat management

    Treesearch

    Ernie P. Wiggers

    1989-01-01

    Simply stated, habitat is where an animal lives and must include all the resources an animal needs to survive and reproduce. An animal's habitat has to provide five essential factors: food, cover, water, space, and interspersion. Habitat management is identifying which factors are scarce enough to limit populations, and then improving the habitat to remove the...

  13. Expandable Lunar Habitat (X-Hab)

    NASA Image and Video Library

    2010-09-23

    Expandable Lunar Habitat (X-Hab).ILC Dover, under contract by NASA Langley Research Center, and in cooperation with NASA Johnson Space Center has designed and manufactured an expandable lunar habitat. This cylindrical habitat, or Expandable Lunar Habitat (X-Hab) is a hybrid system with two hard end caps and a deployable softgoods section in the center.

  14. Habitat associations of three crayfish endemic to the Ouachita Mountain Ecoregion

    USGS Publications Warehouse

    Dyer, Joseph J.; Brewer, Shannon K.

    2018-01-01

    Many crayfish are of conservation concern because of their use of unique habitats and often narrow ranges. In this study, we determined fine-scale habitat use by 3 crayfishes that are endemic to the Ouachita Mountains, in Oklahoma and Arkansas. We sampled Faxonius menae (Mena Crayfish), F. leptogonopodus (Little River Creek Crayfish), and Fallicambarus tenuis (Ouachita Mountain Crayfish) from wet and dry erosional channel units of 29 reaches within the Little River catchment. We compared channel-unit and microhabitat selection for each species. Crayfish of all species and life stages selected erosional channel units more often than depositional units, even though these sites were often dry. Accordingly, crayfish at all life stages typically selected the shallowest available microhabitats. Adult crayfish of all species and juvenile Little River Creek Crayfish selected patches of coarse substrate, and all crayfish tended to use the lowest amount of bedrock available. In general, we showed that these endemic crayfish used erosional channel units of streams, even when the channel units were dry. Conservation efforts that protect erosional channel units and mitigate actions that cause channel downcutting to bedrock would benefit these crayfish, particularly during harsh, summer drying periods.

  15. ESTUARINE HABITAT RESTORATION

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

    Thom, Ronald M.; Borde, Amy B.

    2015-09-01

    Restoring estuarine habitats generally means repairing damages caused by humans and natural forces. Because of the extensive human occupation, development, and use of coastal areas for centuries, the extensive estuarine habitats have been either destroyed or significantly impaired.

  16. Long-term habitat changes in a protected area: Implications for herpetofauna habitat management and restoration.

    PubMed

    Markle, Chantel E; Chow-Fraser, Gillian; Chow-Fraser, Patricia

    2018-01-01

    Point Pelee National Park, located at the southern-most tip of Canada's mainland, historically supported a large number of herpetofauna species; however, despite nearly a century of protection, six snake and five amphibian species have disappeared, and remaining species-at-risk populations are thought to be in decline. We hypothesized that long-term changes in availability and distribution of critical habitat types may have contributed to the disappearance of herpetofauna. To track habitat changes we used aerial image data spanning 85 years (1931-2015) and manually digitized and classified image data using a standardized framework. Change-detection analyses were used to evaluate the relative importance of proportionate loss and fragmentation of 17 habitat types. Marsh habitat diversity and aquatic connectivity has declined since 1931. The marsh matrix transitioned from a graminoid and forb shallow marsh interspersed with water to a cattail dominated marsh, altering critical breeding, foraging, and overwintering habitat. Reduced diversity of marsh habitats appears to be linked to the expansion of invasive Phragmites australis, which invaded prior to 2000. Loss of open habitats such as savanna and meadow has reduced availability of high quality thermoregulation habitat for reptiles. Restoration of the northwestern region and tip of Point Pelee National Park to a mixed landscape of shallow wetlands (cattail, graminoid, forb, open water) and eradication of dense Phragmites stands should improve habitat diversity. Our results suggest that long-term landscape changes resulting from habitat succession and invasive species can negatively affect habitat suitability for herpetofauna and protection of land alone does not necessarily equate to protection of sensitive herpetofauna.

  17. Thermal biology mediates responses of amphibians and reptiles to habitat modification.

    PubMed

    Nowakowski, A Justin; Watling, James I; Thompson, Michelle E; Brusch, George A; Catenazzi, Alessandro; Whitfield, Steven M; Kurz, David J; Suárez-Mayorga, Ángela; Aponte-Gutiérrez, Andrés; Donnelly, Maureen A; Todd, Brian D

    2018-03-01

    Human activities often replace native forests with warmer, modified habitats that represent novel thermal environments for biodiversity. Reducing biodiversity loss hinges upon identifying which species are most sensitive to the environmental conditions that result from habitat modification. Drawing on case studies and a meta-analysis, we examined whether observed and modelled thermal traits, including heat tolerances, variation in body temperatures, and evaporative water loss, explained variation in sensitivity of ectotherms to habitat modification. Low heat tolerances of lizards and amphibians and high evaporative water loss of amphibians were associated with increased sensitivity to habitat modification, often explaining more variation than non-thermal traits. Heat tolerances alone explained 24-66% (mean = 38%) of the variation in species responses, and these trends were largely consistent across geographic locations and spatial scales. As habitat modification alters local microclimates, the thermal biology of species will likely play a key role in the reassembly of terrestrial communities. © 2018 John Wiley & Sons Ltd/CNRS.

  18. Estimating the Effects of Habitat and Biological Interactions in an Avian Community

    PubMed Central

    Dorazio, Robert M.; Connor, Edward F.; Askins, Robert A.

    2015-01-01

    We used repeated sightings of individual birds encountered in community-level surveys to investigate the relative roles of habitat and biological interactions in determining the distribution and abundance of each species. To analyze these data, we developed a multispecies N-mixture model that allowed estimation of both positive and negative correlations between abundances of different species while also estimating the effects of habitat and the effects of errors in detection of each species. Using a combination of single- and multispecies N-mixture modeling, we examined for each species whether our measures of habitat were sufficient to account for the variation in encounter histories of individual birds or whether other habitat variables or interactions with other species needed to be considered. In the community that we studied, habitat appeared to be more influential than biological interactions in determining the distribution and abundance of most avian species. Our results lend support to the hypothesis that abundances of forest specialists are negatively affected by forest fragmentation. Our results also suggest that many species were associated with particular types of vegetation as measured by structural attributes of the forests. The abundances of 6 of the 73 species observed in our study were strongly correlated. These species included large birds (American Crow (Corvus brachyrhynchos) and Red-winged Blackbird (Agelaius phoeniceus)) that forage on the ground in open habitats and small birds (Red-eyed Vireo (Vireo olivaceus), House Wren (Troglodytes aedon), Hooded Warbler (Setophaga citrina), and Prairie Warbler (Setophaga discolor)) that are associated with dense shrub cover. Species abundances were positively correlated within each size group and negatively correlated between groups. Except for the American Crow, which preys on eggs and nestlings of small song birds, none of the other 5 species is known to display direct interactions, so we suspect that

  19. Partial gravity habitat study

    NASA Technical Reports Server (NTRS)

    Capps, Stephen; Lorandos, Jason; Akhidime, Eval; Bunch, Michael; Lund, Denise; Moore, Nathan; Murakawa, Kiosuke

    1989-01-01

    The purpose of this study is to investigate comprehensive design requirements associated with designing habitats for humans in a partial gravity environment, then to apply them to a lunar base design. Other potential sites for application include planetary surfaces such as Mars, variable-gravity research facilities, and a rotating spacecraft. Design requirements for partial gravity environments include locomotion changes in less than normal earth gravity; facility design issues, such as interior configuration, module diameter, and geometry; and volumetric requirements based on the previous as well as psychological issues involved in prolonged isolation. For application to a lunar base, it is necessary to study the exterior architecture and configuration to insure optimum circulation patterns while providing dual egress; radiation protection issues are addressed to provide a safe and healthy environment for the crew; and finally, the overall site is studied to locate all associated facilities in context with the habitat. Mission planning is not the purpose of this study; therefore, a Lockheed scenario is used as an outline for the lunar base application, which is then modified to meet the project needs. The goal of this report is to formulate facts on human reactions to partial gravity environments, derive design requirements based on these facts, and apply the requirements to a partial gravity situation which, for this study, was a lunar base.

  20. Rainwater Wildlife Area Habitat Evaluation Procedures Report; A Columbia Basin Wildlife Mitigation Project.

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

    Childs, Allen B.

    The 8,768 acre Rainwater Wildlife Area was acquired in September 1998 by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) through an agreement with Bonneville Power Administration (BPA) to partially offset habitat losses associated with construction of the John Day and McNary hydroelectric facilities on the mainstem Columbia River. U.S. Fish and Wildlife Service (USFWS) Habitat Evaluation Procedures (HEP) were used to determine the number of habitat units credited to BPA for acquired lands. Upland and riparian forest, upland and riparian shrub, and grassland cover types are evaluated in this study. Targeted wildlife species include downy woodpecker (Picoides pubescens),more » black-capped chickadee (Parus atricopillus), blue grouse (Dendragapus obscurus), great blue heron (Ardea herodias), yellow warbler (Dendroica petechia), mink (Mustela vison), and Western meadowlark (Sturnella neglecta). Habitat surveys were conducted in 1998 and 1999 in accordance with published HEP protocols and included 65,300, 594m{sup 2}2 plots, and 112 one-tenth-acre plots. Between 153.3 and 7,187.46 acres were evaluated for each target wildlife mitigation species. Derived habitat suitability indices were multiplied by corresponding cover-type acreages to determine the number of habitat units for each species. The total baseline habitat units credited to BPA for the Rainwater Wildlife Area and its seven target species is 5,185.3 habitat units. Factors limiting habitat suitability are related to the direct, indirect, and cumulative effects of past livestock grazing, road construction, and timber harvest which have simplified the structure, composition, and diversity of native plant communities. Alternatives for protecting and improving habitat suitability include exclusion of livestock grazing, road de-commissioning/obliteration, reforestation and thinning, control of competing and unwanted vegetation (including noxious weeds), reestablishing displaced or reduced native

  1. Habitat capability model for birds wintering in the Black Hills, South Dakota

    Treesearch

    Mark A. Rumble; Todd R. Mills; Lester D. Flake

    1999-01-01

    Birds are sensitive indicators of vegetation conditions because they have relatively narrow habitat requirements (Martin and Finch 1995). Resident bird populations are relatively stable in winter (Ralph et al. 1993) and more closely associated with specific habitats than during summer (Huff et al. 1991, Manuwal and Huff 1987). Winter can be critical for birds in...

  2. 75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration Strategy; Request... interagency Estuary Habitat Restoration Council, is providing notice of the Council's intent to revise the ''Estuary Habitat Restoration Strategy'' and requesting public comments to guide its revision. DATES...

  3. Vacant habitats in the Universe.

    PubMed

    Cockell, Charles S

    2011-02-01

    The search for life on other planets usually makes the assumption that where there is a habitat, it will contain life. On the present-day Earth, uninhabited habitats (or vacant habitats) are rare, but might occur, for example, in subsurface oils or impact craters that have been thermally sterilized in the past. Beyond Earth, vacant habitats might similarly exist on inhabited planets or on uninhabited planets, for example on a habitable planet where life never originated. The hypothesis that vacant habitats are abundant in the Universe is testable by studying other planets. In this review, I discuss how the study of vacant habitats might ultimately inform an understanding of how life has influenced geochemical conditions on Earth. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. A habitat assessment for Florida panther population expansion into central Florida

    USGS Publications Warehouse

    Thatcher, C.A.; Van Manen, F.T.; Clark, J.D.

    2009-01-01

    One of the goals of the Florida panther (Puma concolor coryi) recovery plan is to expand panther range north of the Caloosahatchee River in central Florida. Our objective was to evaluate the potential of that region to support panthers. We used a geographic information system and the Mahalanobis distance statistic to develop a habitat model based on landscape characteristics associated with panther home ranges. We used cross-validation and an independent telemetry data set to test the habitat model. We also conducted a least-cost path analysis to identify potential habitat linkages and to provide a relative measure of connectivity among habitat patches. Variables in our model were paved road density, major highways, human population density, percentage of the area permanently or semipermanently flooded, and percentage of the area in natural land cover. Our model clearly identified habitat typical of that found within panther home ranges based on model testing with recent telemetry data. We identified 4 potential translocation sites that may support a total of approximately 36 panthers. Although we identified potential habitat linkages, our least-cost path analyses highlighted the extreme isolation of panther habitat in portions of the study area. Human intervention will likely be required if the goal is to establish female panthers north of the Caloosahatchee in the near term.

  5. Habitat quality affects the incidence of morphological abnormalities in the endangered salamander Ambystoma ordinarium

    PubMed Central

    2017-01-01

    Identification of early warning signals previous to the occurrence of population decline or extinction is a major challenge for the conservation of animal species. Prevalence of morphological abnormalities in a population can be one of these signals. We registered morphological abnormalities in the salamander Ambystoma ordinarium. We also evaluated the relation between habitat quality and the prevalence of abnormalities in this species. We used scores from rapid bioassessment protocols (RBPs) to assess the habitat quality of streams inhabited by A. ordinarium. A preliminary survey indicated that of 29 streams where this species has been historically registered, 13 might have few or no A. ordinarium. The association between habitat quality and the incidence of morphological abnormalities was evaluated in these 16 streams. Of 502 sampled individuals, 224 (44.62%) had at least one body abnormality. Of the 224 individuals with body abnormalities, 84 (37.5%) presented more than one abnormality. Of a total of 5,522 evaluated morphological characters, 344 (6.74%) were abnormal. Partial loss of gills and missing digits were the most frequent abnormalities. Results of a binomial logistic regression indicated that the probability of a character of an individual to be abnormal was significantly associated with habitat quality; as the levels of the quality of the habitat increased, the prevalence of morphological abnormalities decreased. These results suggest that RBPs are a quick and useful method for assessing the habitat quality of streams inhabited by A. ordinarium. Given that RBPs provide rapid and cost-effective assessments of the ecological health of aquatic ecosystems, it will be important to test if the RBPs protocols can be used to rapidly assess habitat quality for other species of stream amphibians. The negative association between habitat quality and the prevalence of morpohological abnormalities that we found indicates that habitat condition plays an important

  6. Multi-species genetic connectivity in a terrestrial habitat network.

    PubMed

    Marrotte, Robby R; Bowman, Jeff; Brown, Michael G C; Cordes, Chad; Morris, Kimberley Y; Prentice, Melanie B; Wilson, Paul J

    2017-01-01

    Habitat fragmentation reduces genetic connectivity for multiple species, yet conservation efforts tend to rely heavily on single-species connectivity estimates to inform land-use planning. Such conservation activities may benefit from multi-species connectivity estimates, which provide a simple and practical means to mitigate the effects of habitat fragmentation for a larger number of species. To test the validity of a multi-species connectivity model, we used neutral microsatellite genetic datasets of Canada lynx ( Lynx canadensis ), American marten ( Martes americana ), fisher ( Pekania pennanti ), and southern flying squirrel ( Glaucomys volans ) to evaluate multi-species genetic connectivity across Ontario, Canada. We used linear models to compare node-based estimates of genetic connectivity for each species to point-based estimates of landscape connectivity (current density) derived from circuit theory. To our knowledge, we are the first to evaluate current density as a measure of genetic connectivity. Our results depended on landscape context: habitat amount was more important than current density in explaining multi-species genetic connectivity in the northern part of our study area, where habitat was abundant and fragmentation was low. In the south however, where fragmentation was prevalent, genetic connectivity was correlated with current density. Contrary to our expectations however, locations with a high probability of movement as reflected by high current density were negatively associated with gene flow. Subsequent analyses of circuit theory outputs showed that high current density was also associated with high effective resistance, underscoring that the presence of pinch points is not necessarily indicative of gene flow. Overall, our study appears to provide support for the hypothesis that landscape pattern is important when habitat amount is low. We also conclude that while current density is proportional to the probability of movement per unit area

  7. Ecological periodic tables for benthic macrofaunal usage of estuarine habitats in the US Pacific Northwest

    EPA Science Inventory

    Estuary-wide benthic macrofauna─habitat associations were determined for 9 habitats (intertidal eelgrass [Zostera marina], dwarf eelgrass [Zostera japonica], oyster [Crassostrea gigas], mud shrimp [Upogebia pugettensis], ghost shrimp [Neotrypaea californiensis], shell, sand, mud,...

  8. The relative influence of road characteristics and habitat on adjacent lizard populations in arid shrublands

    USGS Publications Warehouse

    Hubbard, Kaylan A.; Chalfoun, Anna D.; Gerow, Kenneth G.

    2016-01-01

    As road networks continue to expand globally, indirect impacts to adjacent wildlife populations remain largely unknown. Simultaneously, reptile populations are declining worldwide and anthropogenic habitat loss and fragmentation are frequently cited causes. We evaluated the relative influence of three different road characteristics (surface treatment, width, and traffic volume) and habitat features on adjacent populations of Northern Sagebrush Lizards (Sceloporus graciosus graciosus), Plateau Fence Lizards (S. tristichus), and Greater Short-Horned Lizards (Phrynosoma hernandesi) in mixed arid shrubland habitats in southwest Wyoming. Neither odds of lizard presence nor relative abundance was significantly related to any of the assessed road characteristics, although there was a trend for higher Sceloporus spp. abundance adjacent to paved roads. Sceloporus spp. relative abundance did not vary systematically with distance to the nearest road. Rather, both Sceloporus spp. and Greater Short-Horned Lizards were associated strongly with particular habitat characteristics adjacent to roads. Sceloporus spp. presence and relative abundance increased with rock cover, relative abundance was associated positively with shrub cover, and presence was associated negatively with grass cover. Greater Short-Horned Lizard presence increased with bare ground and decreased marginally with shrub cover. Our results suggest that habitat attributes are stronger correlates of lizard presence and relative abundance than individual characteristics of adjacent roads, at least in our system. Therefore, an effective conservation approach for these species may be to consider the landscape through which new roads and their associated development would occur, and the impact that placement could have on fragment size and key habitat elements.

  9. Invasive exotic shrub modifies a classic animal-habitat relationship and alters patterns of vertebrate seed predation.

    PubMed

    Guiden, Peter W; Orrock, John L

    2017-02-01

    Recent evidence suggests that invasive exotic plants can provide novel habitats that alter animal behavior. However, it remains unclear whether classic animal-habitat associations that influence the spatial distribution of plant-animal interactions, such as small mammal use of downed woody debris, persist in invaded habitats. We removed an invasive exotic shrub (buckthorn, Rhamnus cathartica) from 7 of 15 plots in Wisconsin. In each plot, we deployed 200 tagged Quercus rubra seeds in November 2014. After five months, tags were recovered to track spatial patterns of small mammal seed predation. Most recovered tags were associated with consumed seeds (95%); live-trapping, ancillary camera-trapping, and previous behavioral studies suggest that white-footed mice (Peromyscus leucopus) were responsible for most seed predation. In habitats without R. cathartica, most seed predation occurred near woody debris. In habitats with R. cathartica, small mammals rarely consumed seeds near woody debris, and seed predation occurred farther from the plot center and was less spatially clustered. Our results illustrate that invasive exotic shrubs can disrupt an otherwise common animal-habitat relationship. Failing to account for changes in habitat use may diminish our ability to predict animal distributions and outcomes of species interactions in novel habitats created by invasive exotic plants. © 2016 by the Ecological Society of America.

  10. Stress physiology of migrant birds during stopover in natural and anthropogenic woodland habitats of the Northern Prairie region.

    PubMed

    Liu, Ming; Swanson, David L

    2014-01-01

    Anthropogenic alterations of woodland habitat may influence stopover biology, which in turn could alter the stress physiology of migratory landbirds. Woodland stopover habitats are scarce in the Northern Prairie region of North America and consist of native riparian corridor woodlands (corridors) and smaller, more isolated woodlots of anthropogenic origin around farmsteads (woodlots). Corridor habitats have been greatly reduced since the time of European settlement, but woodlot habitats have appeared over this same time period. In this study, we compared stopover biology and stress physiology of migratory landbirds using natural and anthropogenic woodland habitats. We first tested for differences between birds in the two habitats for baseline corticosterone (CORTB) and the magnitude of the stress response for individual species, taxonomic families and foraging guilds. Plasma corticosterone increased significantly for all bird groups in both habitats following 30 min of restraint stress (CORT30), and neither CORTB nor the magnitude of the stress response (CORT30 - CORTB) differed significantly between birds in the two habitats. Secondly, because CORTB levels are often elevated and CORT secretion following a stressor is often suppressed for birds in poor body condition, we hypothesized that woodland migrants with higher fattening rates would show reduced CORTB and a robust stress response. We tested this hypothesis by assessing the relationships between plasma corticosterone and plasma metabolites associated with refuelling. We found that CORTB was negatively associated and the magnitude of the stress response positively associated with plasma triglycerides (an indicator of fat deposition), with opposite patterns for corticosterone and plasma β-hydroxybutyrate (an indicator of fat catabolism). These data suggest that both corridor and woodlot habitats serve as effective stopover habitat and that the reduction of corridor habitat and increased reliance on

  11. No net loss of fish habitat: a review and analysis of habitat compensation in Canada.

    PubMed

    Harper, D J; Quigley, J T

    2005-09-01

    The achievement of No Net Loss (NNL) through habitat compensation has rarely been assessed in Canada. Files relating to 124 Fisheries Act Section 35(2) authorizations issued by Fisheries and Oceans Canada for the harmful alteration, disruption, and destruction of fish habitat (HADD) were collected and reviewed. Data extracted from these files were pooled and analyzed to provide an indication of the types of HADDs that have been authorized in Canada, what habitats have been affected, and what habitat management approaches have been used when compensating for HADDs and monitoring and ensuring the success of the compensation. Determinations regarding the effectiveness of habitat compensation in achieving NNL were made. Impacts to 419,562 m2 of fish habitat from the 124 authorized HADDs were offset by 1,020,388 m2 of compensatory habitat. Eighty percent of the authorizations had compensation ratios (compensation area:HADD area) of 2:1 or less, and 25% of the authorizations had a compensation ratio that was less than 1:1. In-channel and riparian habitat were the most frequently impacted habitats. Urban development and roads and highways resulted in the greatest areal loss of habitat. The compensation option that was most often selected was the creation of in-kind habitat. The mean duration of post-construction monitoring programs was 3.7 years. Determinations of NNL could only be made for 17 authorizations as a result of poor proponent compliance with monitoring requirements and the qualitative assessment procedures used by the monitoring programs. Adequate resources, proper training, and standardized approaches to data management and monitoring programs are required to ensure that the conservation goal of NNL can be achieved in Canada.

  12. Long-term habitat changes in a protected area: Implications for herpetofauna habitat management and restoration

    PubMed Central

    Chow-Fraser, Gillian; Chow-Fraser, Patricia

    2018-01-01

    Point Pelee National Park, located at the southern-most tip of Canada’s mainland, historically supported a large number of herpetofauna species; however, despite nearly a century of protection, six snake and five amphibian species have disappeared, and remaining species-at-risk populations are thought to be in decline. We hypothesized that long-term changes in availability and distribution of critical habitat types may have contributed to the disappearance of herpetofauna. To track habitat changes we used aerial image data spanning 85 years (1931–2015) and manually digitized and classified image data using a standardized framework. Change-detection analyses were used to evaluate the relative importance of proportionate loss and fragmentation of 17 habitat types. Marsh habitat diversity and aquatic connectivity has declined since 1931. The marsh matrix transitioned from a graminoid and forb shallow marsh interspersed with water to a cattail dominated marsh, altering critical breeding, foraging, and overwintering habitat. Reduced diversity of marsh habitats appears to be linked to the expansion of invasive Phragmites australis, which invaded prior to 2000. Loss of open habitats such as savanna and meadow has reduced availability of high quality thermoregulation habitat for reptiles. Restoration of the northwestern region and tip of Point Pelee National Park to a mixed landscape of shallow wetlands (cattail, graminoid, forb, open water) and eradication of dense Phragmites stands should improve habitat diversity. Our results suggest that long-term landscape changes resulting from habitat succession and invasive species can negatively affect habitat suitability for herpetofauna and protection of land alone does not necessarily equate to protection of sensitive herpetofauna. PMID:29444129

  13. Delineation and mapping of coastal shark habitat within a shallow lagoonal estuary.

    PubMed

    Bangley, Charles W; Paramore, Lee; Dedman, Simon; Rulifson, Roger A

    2018-01-01

    Estuaries function as important nursery and foraging habitats for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and provides a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitats within Pamlico Sound, shark catch and environmental data were analyzed from the 2007-2014 North Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys conducted within the estuary. Principal species were identified and environmental data recorded at survey sites (depth, temperature, salinity, dissolved oxygen, submerged aquatic vegetation (SAV) distance, and inlet distance) were interpolated across Pamlico Sound to create seasonal environmental grids with a 90-m2 cell size. Boosted Regression Tree (BRT) analysis was used to identify the most important environmental factors and ranges associated with presence of each principal species, and the resulting models were used to predict shark capture probability based on the environmental values within the grid cells. The Atlantic Sharpnose Shark (Rhizoprionodon terraenovae), Blacktip Shark (Carcharhinus limbatus), Bull Shark (Carcharhinus leucas), Sandbar Shark (Carcharhinus plumbeus), Smooth Dogfish (Mustelus canis), and Spiny Dogfish (Squalus acanthias) were the principal species in Pamlico Sound. Most species were associated with proximity to the inlet and/or high salinity, and warm temperatures, but the Bull Shark preferred greater inlet distances and the Spiny Dogfish preferred lower temperatures than the other species. Extensive Smooth Dogfish habitat overlap with seagrass beds suggests that seagrass may be a critical part of nursery habitat for this species. Spatial delineation of shark habitat within the estuary will allow for better protection of essential habitat and assessment of potential interactions with other species.

  14. Assessing predation risks for small fish in a large river ecosystem between contrasting habitats and turbidity conditions

    USGS Publications Warehouse

    Dodrill, Michael J.; Yard, Mike; Pine, William E.

    2016-01-01

    This study examined predation risk for juvenile native fish between two riverine shoreline habitats, backwater and debris fan, across three discrete turbidity levels (low, intermediate, high) to understand environmental risks associated with habitat use in a section of the Colorado River in Grand Canyon, AZ. Inferences are particularly important to juvenile native fish, including the federally endangered humpback chub Gila cypha. This species uses a variety of habitats including backwaters which are often considered important rearing areas. Densities of two likely predators, adult rainbow trout Oncorhynchus mykiss and adult humpback chub, were estimated between habitats using binomial mixture models to examine whether higher predator density was associated with patterns of predation risk. Tethering experiments were used to quantify relative predation risk between habitats and turbidity conditions. Under low and intermediate turbidity conditions, debris fan habitat showed higher relative predation risk compared to backwaters. In both habitats the highest predation risk was observed during intermediate turbidity conditions. Density of likely predators did not significantly differ between these habitats. This information can help managers in Grand Canyon weigh flow policy options designed to increase backwater availability or extant turbidity conditions.

  15. Simulated effects of habitat loss and fragmentation on a solitary, mustellid predator

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

    Jager, Yetta; Carr, Eric A; Efroymson, Rebecca Ann

    2005-01-01

    Brine spills associated with petroleum extraction can reduce the amount of suitable habitat and increase habitat fragmentation for many terrestrial animals. We conducted a simulation study to quantify the effects of habitat loss and fragmentation on a solitary mammal predator. To provide focus, we adopted biological attributes of the American badger (Taxidea taxus) and environmental attributes of the Tallgrass Prairie Preserve in Oklahoma. We simulated badger activities on landscapes with different degrees of habitat loss and fragmentation using a spatially explicit and individual-based population model. Both habitat loss and fragmentation increased the incidence of habitat-related mortality and decreased the proportionmore » of eligible females that mated, which decreased final population sizes and the likelihood of persistence. Parameter exploration suggested that steep, threshold-like, responses to habitat loss occurred when animals included high-risk habitat in their territories. Badger populations showed a steeper decline with increasing habitat loss on landscapes fragmented by spills than on less fragmented landscapes. Habitat fragmentation made it difficult for badgers to form high-quality territories, and exposed individuals to higher risk while seeking to establish a territory. Our simulations also suggest that an inability to find mates (an Allee effect) becomes increasingly important for landscapes that support a sparse distribution of territories. Thus, the presence of unmated females with territories may foreshadow population decline in solitary species that do not normally tolerate marginal adults.« less

  16. Foraging habitat for shorebirds in southeastern Missouri and its predicted future availability

    USGS Publications Warehouse

    Twedt, Daniel J.

    2013-01-01

    Water management to protect agriculture in alluvial floodplains often conflicts with wildlife use of seasonal floodwater. Such is the case along the Mississippi River in southeastern Missouri where migrating shorebirds forage in shallow-flooded fields. I estimated the current availability of habitat for foraging shorebirds within the New Madrid and St. Johns Basins based on daily river elevations (1943–2009), under assumptions that shorebirds forage in open habitat with water depth <15 cm and use mudflats for 3 days after exposure. The area of shorebird foraging habitat, based on replicated 50-year random samples, averaged 975 ha per day during spring and 33 ha per day during fall. Adjustments to account for habitat quality associated with different water depths, duration of mudflat exposure, intra-seasonal availability, and state of agricultural crops, indicated the equivalent of 494 ha daily of optimal habitat during spring and 11 ha during fall. Proposed levees and pumps to protect cropland would reduce shorebird foraging habitat by 80 %: to 211 ha (108 optimal ha) per day during spring and 9 ha (<3 optimal ha) per day during fall. Alternative water management that allows natural flooding below a prescribed elevation would retain nearly all existing shorebird foraging habitat during fall and about 60 % of extant habitat during spring.

  17. Can we enhance amphibians' habitat restoration in the post-mining areas?

    PubMed

    Klimaszewski, Krzysztof; Pacholik, Ewa; Snopek, Adam

    2016-09-01

    The study was aimed to evaluate the selected improvements of nature restoration in a depleted gravel pit. The study site consisted of four water reservoirs of different shapes and sizes, flooded after the gravel extraction ended. Ecological succession monitoring, conducted by the Warsaw University of Life Sciences students associated in the Student Scientific Association of Animal Sciences Faculty since the completion of mining, have focused on amphibians. A twofold approach upheld amphibian species population dynamics, as well as selected habitat elements. The restoration practices dedicated to habitat conditions enhancing have been proved to be definitely effective and useful for similar sites.

  18. Desired future condition: Fish habitat in southwestern riparian-stream habitats

    Treesearch

    John N. Rinne

    1996-01-01

    Riparian ecosystems in the southwestern United States provide valuable habitats for many living organisms including native fishes. An analysis of habitat components important to native fishes was made based on the literature, case histories, and unpublished and observational data. Results suggest a natural, surface water hydrograph and lack of introduced species of...

  19. Use of non-alpine anthropogenic habitats by American pikas (Ochotona princeps) in western Oregon, USA

    USGS Publications Warehouse

    Manning, Tom; Hagar, Joan C.

    2011-01-01

    The American pika (Ochotona princeps Richardson) has long been characterized in field guides and popular literature as an obligate inhabitant of alpine talus and as having relatively low dispersal capability. However, recent work reveals pikas to have broader habitat associations than previously reported. Over a large portion of the western slope of the Cascade Range in Oregon, pikas inhabit relatively low-elevation sites far from alpine areas and frequently occur in rocky man-made habitats such as roadcuts or rock quarries. We present observations of pikas in these previously overlooked habitats and discuss implications for (1) the proposed listing of the American pika as an endangered or threatened species; (2) furthering our understanding of pika population dynamics, habitat associations, and dispersal capabilites; and (3) management of federal, state, and private forest lands.

  20. Assessing critical habitat: Evaluating the relative contribution of habitats to population

    EPA Science Inventory

    A principal challenge of species conservation is to identify the specific habitats that are essential for long-term persistence or recovery of imperiled species. However, many approaches to identifying important habitats do not provide direct insight into the contribution of hab...

  1. Coherence between harvest and habitat management -- Joint venture perspectives

    USGS Publications Warehouse

    Baxter, C.K.; Nelson, J.W.; Reinecke, K.J.; Stephens, S.E.

    2006-01-01

    Introduction: In recent months, an ad hoc group of waterfowl scientists, representing the International Association of Fish and Wildlife Agencies (IAFWA) Adaptive Harvest Management (ARM) Task Force and the North American Waterfowl Management Plan (NAWMP) Committee, have collaborated as a Joint Task Group (JTG) to assess options for unifying the population goals guiding waterfowl harvest management and habitat management. The JTG has been charged with bringing coherence to the population goals of the two programs. Characterizing the problem as one of coherence indicates value judgments exist regarding its significance or perhaps existence. For purposes of this paper, we characterize the lack of coherence as the absence of consistent population goals in the two related components of waterfowl conservation habitat and harvest management. Our purpose is to support continued dialogue on the respective goals of these programs and the possible implications of discordant goals to habitat joint ventures. Our objectives are two-fold: (1) illustrate how NAWMP habitat management goals and strategies have been interpreted and pursued in both breeding and wintering areas, and (2) provide perspectives on the linkages between regional habitat management programs and harvest management. The Lower Mississippi Valley and the Prairie Pothole joint ventures (LMVJV and PPJV, respectively) will be used as examples.

  2. Habitat typing versus advanced vegetation classification in western forests

    Treesearch

    Tony Kusbach; John Shaw; James Long; Helga Van Miegroet

    2012-01-01

    Major habitat and community types in northern Utah were compared with plant alliances and associations that were derived from fidelity- and diagnostic-species classification concepts. Each of these classification approaches was associated with important environmental factors. Within a 20,000-ha watershed, 103 forest ecosystems were described by physiographic features,...

  3. The Habitat Project

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2011-01-01

    The Habitat Project is a multiday, differentiated, interdisciplinary environmental science lesson that incorporates skill-building and motivational strategies to internalize ecosystem vocabulary. Middle school students research an animal, display its physical characteristics on a poster, build a three-dimensional habitat and present their work…

  4. Assessing range-wide habitat suitability for the Lesser Prairie-Chicken

    USGS Publications Warehouse

    Jarnevich, Catherine S.; Holcombe, Tracy R.; Grisham, Blake A.; Timmer, Jennifer M.; Boal, Clint W.; Butler, Matthew; Pitman, James C.; Kyle, Sean; Klute, David; Beauprez, Grant M.; Janus, Allan; Van Pelt, William E.

    2016-01-01

    Population declines of many wildlife species have been linked to habitat loss incurred through land-use change. Incorporation of conservation planning into development planning may mitigate these impacts. The threatened Lesser Prairie-Chicken (Tympanuchus pallidicinctus) is experiencing loss of native habitat and high levels of energy development across its multijurisdictional range. Our goal was to explore relationships of the species occurrence with landscape characteristics and anthropogenic effects influencing its distribution through evaluation of habitat suitability associated with one particular habitat usage, lekking. Lekking has been relatively well-surveyed, though not consistently, in all jurisdictions. All five states in which Lesser Prairie-Chickens occur cooperated in development of a Maxent habitat suitability model. We created two models, one with state as a factor and one without state. When state was included it was the most important predictor, followed by percent of land cover consisting of known or suspected used vegetation classes within a 5000 m area around a lek. Without state, land cover was the most important predictor of relative habitat suitability for leks. Among the anthropogenic predictors, landscape condition, a measure of human impact integrated across several factors, was most important, ranking third in importance without state. These results quantify the relative suitability of the landscape within the current occupied range of Lesser Prairie-Chickens. These models, combined with other landscape information, form the basis of a habitat assessment tool that can be used to guide siting of development projects and targeting of areas for conservation.

  5. 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.

  6. Habitat Suitability Index Models: Laughing gull

    USGS Publications Warehouse

    Zale, Alexander V.; Mulholland, Rosemarie

    1985-01-01

    A review and synthesis of existing information were used to develop a habitat model for laughing gull (Larus atricilla). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimally suitable habitat) for areas along the Gulf of Mexico coast. Habitat suitability indices are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for application of the model and techniques for measuring model variables are described.

  7. Mosquito vector-associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod-borne diseases.

    PubMed

    Thongsripong, Panpim; Chandler, James Angus; Green, Amy B; Kittayapong, Pattamaporn; Wilcox, Bruce A; Kapan, Durrell D; Bennett, Shannon N

    2018-01-01

    Vector-borne diseases are a major health burden, yet factors affecting their spread are only partially understood. For example, microbial symbionts can impact mosquito reproduction, survival, and vectorial capacity, and hence affect disease transmission. Nonetheless, current knowledge of mosquito-associated microbial communities is limited. To characterize the bacterial and eukaryotic microbial communities of multiple vector species collected from different habitat types in disease endemic areas, we employed next-generation 454 pyrosequencing of 16S and 18S rRNA amplicon libraries, also known as metabarcoding. We investigated pooled whole adult mosquitoes of three medically important vectors, Aedes aegypti , Ae. albopictus , and Culex quinquefasciatus, collected from different habitats across central Thailand where we previously characterized mosquito diversity. Our results indicate that diversity within the mosquito microbiota is low, with the majority of microbes assigned to one or a few taxa. Two of the most common eukaryotic and bacterial genera recovered ( Ascogregarina and Wolbachia, respectively) are known mosquito endosymbionts with potentially parasitic and long evolutionary relationships with their hosts. Patterns of microbial composition and diversity appeared to differ by both vector species and habitat for a given species, although high variability between samples suggests a strong stochastic element to microbiota assembly. In general, our findings suggest that multiple factors, such as habitat condition and mosquito species identity, may influence overall microbial community composition, and thus provide a basis for further investigations into the interactions between vectors, their microbial communities, and human-impacted landscapes that may ultimately affect vector-borne disease risk.

  8. Determining habitat quality for species that demonstrate dynamic habitat selection

    USGS Publications Warehouse

    Beerens, James M.; Frederick, Peter C; Noonburg, Erik G; Gawlik, Dale E.

    2015-01-01

    Determining habitat quality for wildlife populations requires relating a species' habitat to its survival and reproduction. Within a season, species occurrence and density can be disconnected from measures of habitat quality when resources are highly seasonal, unpredictable over time, and patchy. Here we establish an explicit link among dynamic selection of changing resources, spatio-temporal species distributions, and fitness for predictive abundance and occurrence models that are used for short-term water management and long-term restoration planning. We used the wading bird distribution and evaluation models (WADEM) that estimate (1) daily changes in selection across resource gradients, (2) landscape abundance of flocks and individuals, (3) conspecific foraging aggregation, and (4) resource unit occurrence (at fixed 400 m cells) to quantify habitat quality and its consequences on reproduction for wetland indicator species. We linked maximum annual numbers of nests detected across the study area and nesting success of Great Egrets (Ardea alba), White Ibises (Eudocimus albus), and Wood Storks (Mycteria americana) over a 20-year period to estimated daily dynamics of food resources produced by WADEM over a 7490 km2 area. For all species, increases in predicted species abundance in March and high abundance in April were strongly linked to breeding responses. Great Egret nesting effort and success were higher when birds also showed greater conspecific foraging aggregation. Synthesis and applications: This study provides the first empirical evidence that dynamic habitat selection processes and distributions of wading birds over environmental gradients are linked with reproductive measures over periods of decades. Further, predictor variables at a variety of temporal (daily-multiannual) resolutions and spatial (400 m to regional) scales effectively explained variation in ecological processes that change habitat quality. The process used here allows managers to develop

  9. Diversity and Community Composition of Vertebrates in Desert River Habitats

    PubMed Central

    Free, C. L.; Baxter, G. S.; Dickman, C. R.; Lisle, A.; Leung, L. K.-P.

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  10. Quantifying fish habitat associated with stream simulation design culverts in northern Wisconsin

    Treesearch

    A. Timm; D. Higgins; J. Stanovick; R. Kolka; S. Eggert

    2017-01-01

    This study investigated the effects of culvert replacement design on fish habitat and fish weight by comparing substrate diversity and weight at three stream simulation (SS)-design and three bankfull and backwater (BB)-design sites on the Chequamegon-Nicolet National Forest, Wisconsin. Stream channel cross-sections, Wolman substrate particle counts, and single-pass...

  11. Integrating SAS and GIS software to improve habitat-use estimates from radiotelemetry data

    USGS Publications Warehouse

    Kenow, K.P.; Wright, R.G.; Samuel, M.D.; Rasmussen, P.W.

    2001-01-01

    Radiotelemetry has been used commonly to remotely determine habitat use by a variety of wildlife species. However, habitat misclassification can occur because the true location of a radiomarked animal can only be estimated. Analytical methods that provide improved estimates of habitat use from radiotelemetry location data using a subsampling approach have been proposed previously. We developed software, based on these methods, to conduct improved habitat-use analyses. A Statistical Analysis System (SAS)-executable file generates a random subsample of points from the error distribution of an estimated animal location and formats the output into ARC/INFO-compatible coordinate and attribute files. An associated ARC/INFO Arc Macro Language (AML) creates a coverage of the random points, determines the habitat type at each random point from an existing habitat coverage, sums the number of subsample points by habitat type for each location, and outputs tile results in ASCII format. The proportion and precision of habitat types used is calculated from the subsample of points generated for each radiotelemetry location. We illustrate the method and software by analysis of radiotelemetry data for a female wild turkey (Meleagris gallopavo).

  12. Relative Importance of Coral Cover, Habitat Complexity and Diversity in Determining the Structure of Reef Fish Communities

    PubMed Central

    Komyakova, Valeriya; Munday, Philip L.; Jones, Geoffrey P.

    2013-01-01

    The structure of coral reef habitat has a pronounced influence on the diversity, composition and abundance of reef-associated fishes. However, the particular features of the habitat that are most critical are not always known. Coral habitats can vary in many characteristics, notably live coral cover, topographic complexity and coral diversity, but the relative effects of these habitat characteristics are often not distinguished. Here, we investigate the strength of the relationships between these habitat features and local fish diversity, abundance and community structure in the lagoon of Lizard Island, Great Barrier Reef. In a spatial comparison using sixty-six 2m2 quadrats, fish species richness, total abundance and community structure were examined in relation to a wide range of habitat variables, including topographic complexity, habitat diversity, coral diversity, coral species richness, hard coral cover, branching coral cover and the cover of corymbose corals. Fish species richness and total abundance were strongly associated with coral species richness and cover, but only weakly associated with topographic complexity. Regression tree analysis showed that coral species richness accounted for most of the variation in fish species richness (63.6%), while hard coral cover explained more variation in total fish abundance (17.4%), than any other variable. In contrast, topographic complexity accounted for little spatial variation in reef fish assemblages. In degrading coral reef environments, the potential effects of loss of coral cover and topographic complexity are often emphasized, but these findings suggest that reduced coral biodiversity may ultimately have an equal, or greater, impact on reef-associated fish communities. PMID:24349455

  13. Relative importance of coral cover, habitat complexity and diversity in determining the structure of reef fish communities.

    PubMed

    Komyakova, Valeriya; Munday, Philip L; Jones, Geoffrey P

    2013-01-01

    The structure of coral reef habitat has a pronounced influence on the diversity, composition and abundance of reef-associated fishes. However, the particular features of the habitat that are most critical are not always known. Coral habitats can vary in many characteristics, notably live coral cover, topographic complexity and coral diversity, but the relative effects of these habitat characteristics are often not distinguished. Here, we investigate the strength of the relationships between these habitat features and local fish diversity, abundance and community structure in the lagoon of Lizard Island, Great Barrier Reef. In a spatial comparison using sixty-six 2m(2) quadrats, fish species richness, total abundance and community structure were examined in relation to a wide range of habitat variables, including topographic complexity, habitat diversity, coral diversity, coral species richness, hard coral cover, branching coral cover and the cover of corymbose corals. Fish species richness and total abundance were strongly associated with coral species richness and cover, but only weakly associated with topographic complexity. Regression tree analysis showed that coral species richness accounted for most of the variation in fish species richness (63.6%), while hard coral cover explained more variation in total fish abundance (17.4%), than any other variable. In contrast, topographic complexity accounted for little spatial variation in reef fish assemblages. In degrading coral reef environments, the potential effects of loss of coral cover and topographic complexity are often emphasized, but these findings suggest that reduced coral biodiversity may ultimately have an equal, or greater, impact on reef-associated fish communities.

  14. CTUIR Umatilla Anadromous Fisheries Habitat Project : A Columbia River Basin Fish Habitat Project 2008 Annual Report.

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

    Hoverson, Eric D.; Amonette, Alexandra

    The Umatilla Anadromous Fisheries Habitat Project (UAFHP) is an ongoing effort to protect, enhance, and restore riparian and instream habitat for the natural production of anadromous salmonids in the Umatilla River Basin, Northeast Oregon. Flow quantity, water temperature, passage, and lack of in-stream channel complexity have been identified as the key limiting factors in the basin. During the 2008 Fiscal Year (FY) reporting period (February 1, 2008-January 31, 2009) primary project activities focused on improving instream and riparian habitat complexity, migrational passage, and restoring natural channel morphology and floodplain function. Eight primary fisheries habitat enhancement projects were implemented on Meachammore » Creek, Birch Creek, West Birch Creek, McKay Creek, West Fork Spring Hollow, and the Umatilla River. Specific restoration actions included: (1) rectifying one fish passage barrier on West Birch Creek; (2) participating in six projects planting 10,000 trees and seeding 3225 pounds of native grasses; (3) donating 1000 ft of fencing and 1208 fence posts and associated hardware for 3.6 miles of livestock exclusion fencing projects in riparian areas of West Birch and Meacham Creek, and for tree screens to protect against beaver damage on West Fork Spring Hollow Creek; (4) using biological control (insects) to reduce noxious weeds on three treatment areas covering five acres on Meacham Creek; (5) planning activities for a levee setback project on Meacham Creek. We participated in additional secondary projects as opportunities arose. Baseline and ongoing monitoring and evaluation activities were also completed on major project areas such as conducting photo point monitoring strategies activities at the Meacham Creek Large Wood Implementation Project site (FY2006) and at additional easements and planned project sites. Fish surveys and aquatic habitat inventories were conducted at project sites prior to implementation. Proper selection and

  15. Temporal segmentation of animal trajectories informed by habitat use

    USGS Publications Warehouse

    van Toor, Marielle L.; Newman, Scott H.; Takekawa, John Y.; Wegmann, Martin; Safi, Kamran

    2016-01-01

    Most animals live in seasonal environments and experience very different conditions throughout the year. Behavioral strategies like migration, hibernation, and a life cycle adapted to the local seasonality help to cope with fluctuations in environmental conditions. Thus, how an individual utilizes the environment depends both on the current availability of habitat and the behavioral prerequisites of the individual at that time. While the increasing availability and richness of animal movement data has facilitated the development of algorithms that classify behavior by movement geometry, changes in the environmental correlates of animal movement have so far not been exploited for a behavioral annotation. Here, we suggest a method that uses these changes in individual–environment associations to divide animal location data into segments of higher ecological coherence, which we term niche segmentation. We use time series of random forest models to evaluate the transferability of habitat use over time to cluster observational data accordingly. We show that our method is able to identify relevant changes in habitat use corresponding to both changes in the availability of habitat and how it was used using simulated data, and apply our method to a tracking data set of common teal (Anas crecca). The niche segmentation proved to be robust, and segmented habitat suitability outperformed models neglecting the temporal dynamics of habitat use. Overall, we show that it is possible to classify animal trajectories based on changes of habitat use similar to geometric segmentation algorithms. We conclude that such an environmentally informed classification of animal trajectories can provide new insights into an individuals' behavior and enables us to make sensible predictions of how suitable areas might be connected by movement in space and time.

  16. Habitat quality influences population distribution, individual space use and functional responses in habitat selection by a large herbivore.

    PubMed

    Bjørneraas, Kari; Herfindal, Ivar; Solberg, Erling Johan; Sæther, Bernt-Erik; van Moorter, Bram; Rolandsen, Christer Moe

    2012-01-01

    Identifying factors shaping variation in resource selection is central for our understanding of the behaviour and distribution of animals. We examined summer habitat selection and space use by 108 Global Positioning System (GPS)-collared moose in Norway in relation to sex, reproductive status, habitat quality, and availability. Moose selected habitat types based on a combination of forage quality and availability of suitable habitat types. Selection of protective cover was strongest for reproducing females, likely reflecting the need to protect young. Males showed strong selection for habitat types with high quality forage, possibly due to higher energy requirements. Selection for preferred habitat types providing food and cover was a positive function of their availability within home ranges (i.e. not proportional use) indicating functional response in habitat selection. This relationship was not found for unproductive habitat types. Moreover, home ranges with high cover of unproductive habitat types were larger, and smaller home ranges contained higher proportions of the most preferred habitat type. The distribution of moose within the study area was partly related to the distribution of different habitat types. Our study shows how distribution and availability of habitat types providing cover and high-quality food shape ungulate habitat selection and space use.

  17. Ocean acidification alters fish populations indirectly through habitat modification

    NASA Astrophysics Data System (ADS)

    Nagelkerken, Ivan; Russell, Bayden D.; Gillanders, Bronwyn M.; Connell, Sean D.

    2016-01-01

    Ocean ecosystems are predicted to lose biodiversity and productivity from increasing ocean acidification. Although laboratory experiments reveal negative effects of acidification on the behaviour and performance of species, more comprehensive predictions have been hampered by a lack of in situ studies that incorporate the complexity of interactions between species and their environment. We studied CO2 vents from both Northern and Southern hemispheres, using such natural laboratories to investigate the effect of ocean acidification on plant-animal associations embedded within all their natural complexity. Although we substantiate simple direct effects of reduced predator-avoidance behaviour by fishes, as observed in laboratory experiments, we here show that this negative effect is naturally dampened when fish reside in shelter-rich habitats. Importantly, elevated CO2 drove strong increases in the abundance of some fish species through major habitat shifts, associated increases in resources such as habitat and prey availability, and reduced predator abundances. The indirect effects of acidification via resource and predator alterations may have far-reaching consequences for population abundances, and its study provides a framework for a more comprehensive understanding of increasing CO2 emissions as a driver of ecological change.

  18. Landscape responses of bats to habitat fragmentation in Atlantic forest of paraguay

    USGS Publications Warehouse

    Gorresen, P.M.; Willig, M.R.

    2004-01-01

    Understanding effects of habitat loss and fragmentation on populations or communities is critical to effective conservation and restoration. This is particularly important for bats because they provide vital services to ecosystems via pollination and seed dispersal, especially in tropical and subtropical habitats. Based on more than 1,000 h of survey during a 15-month period, we quantified species abundances and community structure of phyllostomid bats at 14 sites in a 3,000-km2 region of eastern Paraguay. Abundance was highest for Artibeus lituratus in deforested landscapes and for Chrotopterus auritus in forested habitats. In contrast, Artibeus fimbriatus, Carollia perspicillata, Glossophaga soricina, Platyrrhinus lineatus, Pygoderma bilabiatum, and Sturnira lilium attained highest abundance in moderately fragmented forest landscapes. Forest cover, patch size, and patch density frequently were associated with abundance of species. At the community level, species richness was highest in partly deforested landscapes, whereas evenness was greatest in forested habitat. In general, the highest diversity of bats occurred in landscapes comprising moderately fragmented forest habitat. This underscores the importance of remnant habitat patches to conservation strategies.

  19. Comparative Genomic Analysis of Bacillus amyloliquefaciens and Bacillus subtilis Reveals Evolutional Traits for Adaptation to Plant-Associated Habitats

    PubMed Central

    Zhang, Nan; Yang, Dongqing; Kendall, Joshua R. A.; Borriss, Rainer; Druzhinina, Irina S.; Kubicek, Christian P.; Shen, Qirong; Zhang, Ruifu

    2016-01-01

    Bacillus subtilis and its sister species B. amyloliquefaciens comprise an evolutionary compact but physiologically versatile group of bacteria that includes strains isolated from diverse habitats. Many of these strains are used as plant growth-promoting rhizobacteria (PGPR) in agriculture and a plant-specialized subspecies of B. amyloliquefaciens—B. amyloliquefaciens subsp. plantarum, has recently been recognized, here we used 31 whole genomes [including two newly sequenced PGPR strains: B. amyloliquefaciens NJN-6 isolated from Musa sp. (banana) and B. subtilis HJ5 from Gossypium sp. (cotton)] to perform comparative analysis and investigate the genomic characteristics and evolution traits of both species in different niches. Phylogenomic analysis indicated that strains isolated from plant-associated (PA) habitats could be distinguished from those from non-plant-associated (nPA) niches in both species. The core genomes of PA strains are more abundant in genes relevant to intermediary metabolism and secondary metabolites biosynthesis as compared with those of nPA strains, and they also possess additional specific genes involved in utilization of plant-derived substrates and synthesis of antibiotics. A further gene gain/loss analysis indicated that only a few of these specific genes (18/192 for B. amyloliquefaciens and 53/688 for B. subtilis) were acquired by PA strains at the initial divergence event, but most were obtained successively by different subgroups of PA stains during the evolutional process. This study demonstrated the genomic differences between PA and nPA B. amyloliquefaciens and B. subtilis from different niches and the involved evolutional traits, and has implications for screening of PGPR strains in agricultural production. PMID:28066362

  20. Genetic effects of landscape, habitat preference and demography on three co-occurring turtle species.

    PubMed

    Reid, Brendan N; Mladenoff, David J; Peery, M Zachariah

    2017-02-01

    Expanding the scope of landscape genetics beyond the level of single species can help to reveal how species traits influence responses to environmental change. Multispecies studies are particularly valuable in highly threatened taxa, such as turtles, in which the impacts of anthropogenic change are strongly influenced by interspecific differences in life history strategies, habitat preferences and mobility. We sampled approximately 1500 individuals of three co-occurring turtle species across a gradient of habitat change (including varying loss of wetlands and agricultural conversion of upland habitats) in the Midwestern USA. We used genetic clustering and multiple regression methods to identify associations between genetic structure and permanent landscape features, past landscape composition and landscape change in each species. Two aquatic generalists (the painted turtle, Chrysemys picta, and the snapping turtle Chelydra serpentina) both exhibited population genetic structure consistent with isolation by distance, modulated by aquatic landscape features. Genetic divergence for the more terrestrial Blanding's turtle (Emydoidea blandingii), on the other hand, was not strongly associated with geographic distance or aquatic features, and Bayesian clustering analysis indicated that many Emydoidea populations were genetically isolated. Despite long generation times, all three species exhibited associations between genetic structure and postsettlement habitat change, indicating that long generation times may not be sufficient to delay genetic drift resulting from recent habitat fragmentation. The concordances in genetic structure observed between aquatic species, as well as isolation in the endangered, long-lived Emydoidea, reinforce the need to consider both landscape composition and demographic factors in assessing differential responses to habitat change in co-occurring species. © 2016 John Wiley & Sons Ltd.

  1. 78 FR 33282 - Endangered and Threatened Wildlife and Plants; Revision of Critical Habitat for Salt Creek Tiger...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... habitat includes saline wetlands and streams associated with Little Salt Creek and encompasses all three habitat areas occupied by the subspecies at the time of listing. It also includes saline wetlands and... beetle is endemic to saline wetlands associated with the Salt Creek watershed and some of its tributaries...

  2. Winter habitat selection patterns of Merriam's turkeys in the southern Black Hills, South Dakota

    Treesearch

    Chad P. Lehman; Mark A. Rumble; Lester D. Flake

    2007-01-01

    In northern areas of their expanded range, information on Merriam's turkeys (Meleagris gallopavo merriami) is lacking, specifically pertaining to wintering behavior and factors associated with winter habitat selection. Forest managers need detailed quantification of the effects of logging and other management practices on wintering habitats...

  3. Habitat loss and gain: Influence on habitat attractiveness for estuarine fish communities

    NASA Astrophysics Data System (ADS)

    Amorim, Eva; Ramos, Sandra; Elliott, Michael; Franco, Anita; Bordalo, Adriano A.

    2017-10-01

    Habitat structure and complexity influence the structuring and functioning of fish communities. Habitat changes are one of the main pressures affecting estuarine systems worldwide, yet the degree and rate of change and its impact on fish communities is still poorly understood. In order to quantify historical modifications in habitat structure, an ecohydrological classification system using physiotopes, i.e. units with homogenous abiotic characteristics, was developed for the lower Lima estuary (NW Portugal). Field data, aerial imagery, historical maps and interpolation methods were used to map input variables, including bathymetry, substratum (hard/soft), sediment composition, hydrodynamics (current velocity) and vegetation coverage. Physiotopes were then mapped for the years of 1933 and 2013 and the areas lost and gained over the 80 years were quantified. The implications of changes for the benthic and demersal fish communities using the lower estuary were estimated using the attractiveness to those communities of each physiotope, while considering the main estuarine habitat functions for fish, namely spawning, nursery, feeding and refuge areas and migratory routes. The lower estuary was highly affected due to urbanisation and development and, following a port/harbour expansion, its boundary moved seaward causing an increase in total area. Modifications led to the loss of most of its sandy and saltmarsh intertidal physiotopes, which were replaced by deeper subtidal physiotopes. The most attractive physiotopes for fish (defined as the way in which they supported the fish ecological features) decreased in area while less attractive ones increased, producing an overall lower attractiveness of the studied area in 2013 compared to 1933. The implications of habitat alterations for the fish using the estuary include potential changes in the nursery carrying capacity and the functioning of the fish community. The study also highlighted the poor knowledge of the impacts of

  4. Strategies for monitoring terrestrial animals and habitats

    Treesearch

    Richard Holthausen; Raymond L. Czaplewski; Don DeLorenzo; Greg Hayward; Winifred B. Kessler; Pat Manley; Kevin S. McKelvey; Douglas S. Powell; Leonard F. Ruggiero; Michael K. Schwartz; Bea Van Horne; Christina D. Vojta

    2005-01-01

    This General Technical Report (GTR) addresses monitoring strategies for terrestrial animals and habitats. It focuses on monitoring associated with National Forest Management Act planning and is intended to apply primarily to monitoring efforts that are broader than individual National Forests. Primary topics covered in the GTR are monitoring requirements; ongoing...

  5. Characterization of Anopheles darlingi (Diptera: Culicidae) larval habitats in Belize, Central America

    NASA Technical Reports Server (NTRS)

    Manguin, S.; Roberts, D. R.; Andre, R. G.; Rejmankova, E.; Hakre, S.

    1996-01-01

    Surveys for larvae of Anopheles darlingi Root were conducted in April, May, and August 1994 in riverine habitats of central Belize (Cayo and Belize districts). An. darlingi was present during both the dry and wet seasons. Larvae were encountered most frequently in patches of floating debris along river margins. The floating mats were often formed by bamboo hanging over the banks and dense submersed bamboo roots. Larvae were found less frequently in lake margins, small lagoons, and ground pools with submersed roots and patches of floating leaves or vegetation. In addition to their association with floating debris, larvae of An. darlingi were associated positively with shade and submersed plants in riverine environments. Samples from river habitats showed the larvae of Anopheles albimanus Wiedemann to be strongly associated with sun-exposed sites containing green or blue-green algae. Unlike An. darlingi, An. albimanus was an ubiquitous mosquito, the immatures of which occurred in a wide variety of riverine and nonriverine aquatic habitats. Based on published reports and our experience, the association of An. darlingi with river systems was verified, and its distribution in Central America and Mexico was mapped.

  6. The interplay between habitat structure and chemical contaminants on biotic responses of benthic organisms

    PubMed Central

    Matias, Miguel G.; Coleman, Ross A.

    2016-01-01

    Habitat structure influences the diversity and distribution of organisms, potentially affecting their response to disturbances by either affecting their ‘susceptibility’ or through the provision of resources that can mitigate impacts of disturbances. Chemical disturbances due to contamination are associated with decreases in diversity and functioning of systems and are also likely to increase due to coastal urbanisation. Understanding how habitat structure interacts with contaminants is essential to predict and therefore manage such effects, minimising their consequences to marine systems. Here, we manipulated two structurally different habitats and exposed them to different types of contaminants. The effects of contamination and habitat structure interacted, affecting species richness. More complex experimental habitats were colonized by a greater diversity of organisms than the less complex habitats. These differences disappeared, however, when habitats were exposed to contaminants, suggesting that contaminants can override effects of habitats structure at small spatial scales. These results provide insight into the complex ways that habitat structure and contamination interact and the need to incorporate evidence of biotic responses from individual disturbances to multiple stressors. Such effects need to be taken into account when designing and planning management and conservation strategies to natural systems. PMID:27168991

  7. Anopheline larval habitats seasonality and species distribution: a prerequisite for effective targeted larval habitats control programmes.

    PubMed

    Kweka, Eliningaya J; Zhou, Guofa; Munga, Stephen; Lee, Ming-Chieh; Atieli, Harrysone E; Nyindo, Mramba; Githeko, Andrew K; Yan, Guiyun

    2012-01-01

    Larval control is of paramount importance in the reduction of malaria vector abundance and subsequent disease transmission reduction. Understanding larval habitat succession and its ecology in different land use managements and cropping systems can give an insight for effective larval source management practices. This study investigated larval habitat succession and ecological parameters which influence larval abundance in malaria epidemic prone areas of western Kenya. A total of 51 aquatic habitats positive for anopheline larvae were surveyed and visited once a week for a period of 85 weeks in succession. Habitats were selected and identified. Mosquito larval species, physico-chemical parameters, habitat size, grass cover, crop cycle and distance to nearest house were recorded. Polymerase chain reaction revealed that An. gambiae s.l was the most dominant vector species comprised of An.gambiae s.s (77.60%) and An.arabiensis (18.34%), the remaining 4.06% had no amplification by polymerase chain reaction. Physico-chemical parameters and habitat size significantly influenced abundance of An. gambiae s.s (P = 0.024) and An. arabiensis (P = 0.002) larvae. Further, larval species abundance was influenced by crop cycle (P≤0.001), grass cover (P≤0.001), while distance to nearest houses significantly influenced the abundance of mosquito species larvae (r = 0.920;P≤0.001). The number of predator species influenced mosquito larval abundance in different habitat types. Crop weeding significantly influenced with the abundance of An.gambiae s.l (P≤0.001) when preceded with fertilizer application. Significantly higher anopheline larval abundance was recorded in habitats in pasture compared to farmland (P = 0.002). When habitat stability and habitat types were considered, hoof print were the most productive followed by disused goldmines. These findings suggest that implementation of effective larval control programme should be targeted with larval habitats

  8. Patterns of fish assemblage structure and habitat use among main- and side-channel environments in the lower Kootenai River, Idaho

    USGS Publications Warehouse

    Watkins, Carson J.; Stevens, Bryan S.; Quist, Michael C.; Shepard, Bradley B.; Ireland, Susan C.

    2015-01-01

    The lower Kootenai River, Idaho, was sampled during the summers of 2012 and 2013 to evaluate its fish assemblage structure at seven sites within main- and side-channel habitats where large-scale habitat rehabilitation was undertaken. Understanding the current patterns of fish assemblage structure and their relationships with habitat is important for evaluating the effects of past and future rehabilitation projects on the river. Species-specific habitat associations were modeled, and the variables that best explained the occurrence and relative abundance of fish were identified in order to guide future habitat rehabilitation so that it benefits native species. The results indicated that the side-channel habitats supported higher species richness than the main-channel habitats and that nonnative fishes were closely associated with newly rehabilitated habitats. This research provides valuable insight on the current fish assemblages in the Kootenai River and the assemblage-level responses that may occur as a result of future rehabilitation activities.

  9. Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot

    PubMed Central

    2012-01-01

    Background Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor. Results Elevation, slope, stream size, depth and water temperature were identified by both approaches as the most important causal factors for the spatial distribution of the fishes. However, the species showed marked differences in their responses to these environmental variables. Elevation and slope were of primary importance for the laterally compressed Sandelia spp. which had an upstream boundary below 430 m above sea level. The fusiform shaped Pseudobarbus ‘Breede’ was strongly influenced by stream width and water temperature. The small anguilliform shaped Galaxias ‘nebula’ was more sensitive to stream size and depth, and also penetrated into reaches at higher elevation than Sandelia spp. and Pseudobarbus ‘Breede’. Conclusions The hypothesis that stream fishes have a common response to environmental descriptors is rejected. The contrasting habitat associations of stream fishes considered in this study could be a reflection of their morphological divergence which may allow them to exploit specific habitats that differ in their environmental stressors. Findings of this study encourage wider application of complementary methods in ecological studies, as they provide more confidence and deeper insights into the variables that should be managed to achieve desired

  10. Brackish habitat dictates cultivable Actinobacterial diversity from marine sponges

    PubMed Central

    Chanana, Shaurya; Adnani, Navid; Szachowicz, Emily; Braun, Doug R.; Harper, Mary Kay; Wyche, Thomas P.; Bugni, Tim S.

    2017-01-01

    Bacterial communities associated with marine invertebrates such as sponges and ascidians have demonstrated potential as sources of bio-medically relevant small molecules. Metagenomic analysis has shown that many of these invertebrates harbor populations of Actinobacteria, many of which are cultivable. While some populations within invertebrates are transmitted vertically, others are obtained from the environment. We hypothesized that cultivable diversity from sponges living in brackish mangrove habitats have associations with Actinobacterial populations that differ from those found in clear tropical waters. In this study, we analyzed the cultivable Actinobacterial populations from sponges found in these two distinct habitats with the aim of understanding the secondary metabolite potential. Importantly, we wanted to broadly evaluate the potential differences among these groups to guide future Actinobacterial collection strategies for the purposes of drug discovery. PMID:28692665

  11. Reproductive habitat selection in alien and native populations of the genus Discoglossus

    NASA Astrophysics Data System (ADS)

    Escoriza, Daniel; Boix, Dani

    2014-08-01

    The existence of suitable breeding habitats is an important factor explaining the regional presence of an anuran species. This study examined patterns of habitat selection in populations of three species of the genus Discoglossus: Discoglossusgalganoi (south-western Iberian Peninsula), Discoglossusscovazzi (Morocco) and Discoglossuspictus (three different areas were included in the study: Sicily, Tunisia and north-eastern Iberian Peninsula). The populations of D. pictus on the Iberian Peninsula are allochthonous, and analysis of these patterns may provide insights into the processes that regulate the invasion phase. The hypotheses tested were: (i) congeneric species show the same patterns of habitat selection, and alien species have been established following these patterns; (ii) there are differences in species associations between assemblages structured deterministically and by chance, i.e. native versus invaded assemblages. The larval habitats of three species of this genus were characterized by measuring physical and chemical parameters of the water bodies. We examined the covariation between the presence of Discoglossus species and the species richness of sympatric anurans, and investigated a possible relationship between morphological similarity (as a proxy of functional group) and overlap in habitat use. The results showed that congeneric species are morphologically conservative and also select very similar types of aquatic habitat. The alien population and other sympatric species showed a high degree of overlap in habitat use, which was greater than that observed in the native assemblage with a similar functional richness. Species associations were not structured on the basis of morphological similarity in any of the assemblages. Among native populations, the presence of Discoglossus was either negatively correlated or not significantly correlated with species richness. Only the alien population showed a positive correlation between its presence and species

  12. Delineation and mapping of coastal shark habitat within a shallow lagoonal estuary

    PubMed Central

    Paramore, Lee; Dedman, Simon; Rulifson, Roger A.

    2018-01-01

    Estuaries function as important nursery and foraging habitats for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and provides a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitats within Pamlico Sound, shark catch and environmental data were analyzed from the 2007–2014 North Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys conducted within the estuary. Principal species were identified and environmental data recorded at survey sites (depth, temperature, salinity, dissolved oxygen, submerged aquatic vegetation (SAV) distance, and inlet distance) were interpolated across Pamlico Sound to create seasonal environmental grids with a 90-m2 cell size. Boosted Regression Tree (BRT) analysis was used to identify the most important environmental factors and ranges associated with presence of each principal species, and the resulting models were used to predict shark capture probability based on the environmental values within the grid cells. The Atlantic Sharpnose Shark (Rhizoprionodon terraenovae), Blacktip Shark (Carcharhinus limbatus), Bull Shark (Carcharhinus leucas), Sandbar Shark (Carcharhinus plumbeus), Smooth Dogfish (Mustelus canis), and Spiny Dogfish (Squalus acanthias) were the principal species in Pamlico Sound. Most species were associated with proximity to the inlet and/or high salinity, and warm temperatures, but the Bull Shark preferred greater inlet distances and the Spiny Dogfish preferred lower temperatures than the other species. Extensive Smooth Dogfish habitat overlap with seagrass beds suggests that seagrass may be a critical part of nursery habitat for this species. Spatial delineation of shark habitat within the estuary will allow for better protection of essential habitat and assessment of potential interactions with other species. PMID:29649261

  13. Functional proteomic analyses of Bothrops atrox venom reveals phenotypes associated with habitat variation in the Amazon.

    PubMed

    Sousa, Leijiane F; Portes-Junior, José A; Nicolau, Carolina A; Bernardoni, Juliana L; Nishiyama, Milton Y; Amazonas, Diana R; Freitas-de-Sousa, Luciana A; Mourão, Rosa Hv; Chalkidis, Hipócrates M; Valente, Richard H; Moura-da-Silva, Ana M

    2017-04-21

    Venom variability is commonly reported for venomous snakes including Bothrops atrox. Here, we compared the composition of venoms from B. atrox snakes collected at Amazonian conserved habitats (terra-firme upland forest and várzea) and human modified areas (pasture and degraded areas). Venom samples were submitted to shotgun proteomic analysis as a whole or compared after fractionation by reversed-phase chromatography. Whole venom proteomes revealed a similar composition among the venoms with predominance of SVMPs, CTLs, and SVSPs and intermediate amounts of PLA 2 s and LAAOs. However, when distribution of particular isoforms was analyzed by either method, the venom from várzea snakes showed a decrease in hemorrhagic SVMPs and an increase in SVSPs, and procoagulant SVMPs and PLA 2 s. These differences were validated by experimental approaches including both enzymatic and in vivo assays, and indicated restrictions in respect to antivenom efficacy to variable components. Thus, proteomic analysis at the isoform level combined to in silico prediction of functional properties may indicate venom biological activity. These results also suggest that the prevalence of functionally distinct isoforms contributes to the variability of the venoms and could reflect the adaptation of B. atrox to distinct prey communities in different Amazon habitats. In this report, we compared isoforms present in venoms from snakes collected at different Amazonian habitats. By means of a species venom gland transcriptome and the in silico functional prediction of each isoform, we were able to predict the principal venom activities in vitro and in animal models. We also showed remarkable differences in the venom pools from snakes collected at the floodplain (várzea habitat) compared to other habitats. Not only was this venom less hemorrhagic and more procoagulant, when compared to the venom pools from the other three habitats studied, but also this enhanced procoagulant activity was not

  14. The importance of sea ice for exchange of habitat-specific protist communities in the Central Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Hardge, Kristin; Peeken, Ilka; Neuhaus, Stefan; Lange, Benjamin A.; Stock, Alexandra; Stoeck, Thorsten; Weinisch, Lea; Metfies, Katja

    2017-01-01

    Sea ice is one of the main features influencing the Arctic marine protist community composition and diversity in sea ice and sea water. We analyzed protist communities within sea ice, melt pond water, under-ice water and deep-chlorophyll maximum water at eight sea ice stations sampled during summer of the 2012 record sea ice minimum year. Using Illumina sequencing, we identified characteristic communities associated with specific habitats and investigated protist exchange between these habitats. The highest abundance and diversity of unique taxa were found in sea ice, particularly in multi-year ice (MYI), highlighting the importance of sea ice as a unique habitat for sea ice protists. Melting of sea ice was associated with increased exchange of communities between sea ice and the underlying water column. In contrast, sea ice formation was associated with increased exchange between all four habitats, suggesting that brine rejection from the ice is an important factor for species redistribution in the Central Arctic. Ubiquitous taxa (e.g. Gymnodinium) that occurred in all habitats still had habitat-preferences. This demonstrates a limited ability to survive in adjacent but different environments. Our results suggest that the continued reduction of sea ice extent, and particularly of MYI, will likely lead to diminished protist exchange and subsequently, could reduce species diversity in all habitats of the Central Arctic Ocean. An important component of the unique sea ice protist community could be endangered because specialized taxa restricted to this habitat may not be able to adapt to rapid environmental changes.

  15. Diet composition of age-0 fishes in created habitats of the Lower Missouri River

    USGS Publications Warehouse

    Starks, Trevor A.; Long, James M.

    2017-01-01

    Channelization of the Missouri River has greatly reduced the availability of shallow water habitats used by many larval and juvenile fishes and contributed to imperilment of floodplain-dependent biota. Creation of small side channels, or chutes, is being used to restore shallow water habitat and reverse negative environmental effects associated with channelization. In the summer of 2012, the U.S. Army Corps of Engineers collected early life stages of fishes from constructed chutes and nearby unrestored shallow habitats at six sites on the Missouri River between Rulo, Nebraska and St. Louis, Missouri. We compared the diets of two abundant species of fishes to test the hypothesis that created shallow chutes provided better foraging habitat for early life stages than nearby unrestored shallow habitats. Graphical analysis of feeding patterns of freshwater drum indicated specialization on chironomid larvae, which were consumed in greater numbers in unrestored mainstem reaches compared to chutes. Hiodon spp. were more generalist feeders with no differences in prey use between habitat types. Significantly greater numbers of individuals with empty stomachs were observed in chute shallow-water habitats, indicating poor foraging habitat. For these two species, constructed chute shallow-water habitat does not appear to provide the hypothesized benefits of higher quality foraging habitat.

  16. Habitat Suitability Index Models: Hairy woodpecker

    USGS Publications Warehouse

    Sousa, Patrick J.

    1987-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the hairy woodpecker (Picoides villosus). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  17. Habitat Suitability Index Models: Snapping turtle

    USGS Publications Warehouse

    Graves, Brent M.; Anderson, Stanley H.

    1987-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the snapping turtle (Chelydra serpentina). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) and 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  18. Habitat Suitability Index Models: Spotted owl

    USGS Publications Warehouse

    Laymon, Stephen A.; Salwasser, Hal; Barrett, Reginald H.

    1985-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the spotted owl (Strix occidentalis). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  19. Serengeti real estate: density vs. fitness-based indicators of lion habitat quality.

    PubMed

    Mosser, Anna; Fryxell, John M; Eberly, Lynn; Packer, Craig

    2009-10-01

    Habitat quality is typically inferred by assuming a direct relationship between consumer density and resource abundance, although it has been suggested that consumer fitness may be a more accurate measure of habitat quality. We examined density vs. fitness-based measures of habitat quality for lions in the Serengeti National Park, Tanzania. A 40-year average of female reproductive success (yearling cubs per female) was best explained by proximity to river confluences, whereas patterns of productivity (yearling cubs per km(2)) and adult female density (individuals per km(2)) were associated with more general measures of habitat quality and areas of shelter in poor habitat. This suggests that density may not accurately distinguish between high-quality 'source' areas and low-quality sites that merely provide refuges for effectively non-reproductive individuals. Our results indicate that density may be a misleading indicator of real estate value, particularly for populations that do not conform to an ideal free distribution.

  20. Projected gains and losses of wildlife habitat from bioenergy-induced landscape change

    USGS Publications Warehouse

    Tarr, Nathan M.; Rubino, Matthew J.; Costanza, Jennifer K.; McKerrow, Alexa; Collazo, Jaime A.; Abt, Robert C.

    2016-01-01

    Domestic and foreign renewable energy targets and financial incentives have increased demand for woody biomass and bioenergy in the southeastern United States. This demand is expected to be met through purpose-grown agricultural bioenergy crops, short-rotation tree plantations, thinning and harvest of planted and natural forests, and forest harvest residues. With results from a forest economics model, spatially explicit state-and-transition simulation models, and species–habitat models, we projected change in habitat amount for 16 wildlife species caused by meeting a renewable fuel target and expected demand for wood pellets in North Carolina, USA. We projected changes over 40 years under a baseline ‘business-as-usual’ scenario without bioenergy production and five scenarios with unique feedstock portfolios. Bioenergy demand had potential to influence trends in habitat availability for some species in our study area. We found variation in impacts among species, and no scenario was the ‘best’ or ‘worst’ across all species. Our models projected that shrub-associated species would gain habitat under some scenarios because of increases in the amount of regenerating forests on the landscape, while species restricted to mature forests would lose habitat. Some forest species could also lose habitat from the conversion of forests on marginal soils to purpose-grown feedstocks. The conversion of agricultural lands on marginal soils to purpose-grown feedstocks increased habitat losses for one species with strong associations with pasture, which is being lost to urbanization in our study region. Our results indicate that landscape-scale impacts on wildlife habitat will vary among species and depend upon the bioenergy feedstock portfolio. Therefore, decisions about bioenergy and wildlife will likely involve trade-offs among wildlife species, and the choice of focal species is likely to affect the results of landscape-scale assessments. We offer general principals

  1. Habitat and co-occurrence of native and invasive crayfish in the Pacific Northwest, USA

    USGS Publications Warehouse

    Pearl, Christopher A.; Adams, Michael J.; McCreary, Brome

    2013-01-01

    Biological invasions can have dramatic effects on freshwater ecosystems and introduced crayfish can be particularly impacting. We document crayfish distribution in three large hydrographic basins (Rogue, Umpqua, Willamette/Columbia) in the Pacific Northwest USA. We used occupancy analyses to investigate habitat relationships and evidence for displacement of native Pacifastacus leniusculus (Dana, 1852) by two invaders. We found invasive Procambarus clarkii (Girard, 1852), in 51 of 283 sites and in all three hydrographic basins. We found invasive Orconectes n. neglectus (Faxon, 1885) at 68% of sites in the Rogue basin and provide first documentation of their broad distribution in the Umpqua basin. We found P. clarkii in both lentic and lotic habitats, and it was positively associated with manmade sites. P. leniusculus was positively associated with lotic habitats and negatively related to manmade sites. In the Rogue and Umpqua basins, O. n. neglectus and P. leniusculus were similar in their habitat associations. We did not find a negative relationship in site occupancy between O. n. neglectus and P. leniusculus. Our data suggest that P. clarkii has potential to locally displace P. leniusculus. There is still time for preventive measures to limit the spread of the invasive crayfish in this region.

  2. Scale-dependent seasonal pool habitat use by sympatric Wild Brook Trout and Brown Trout populations

    USGS Publications Warehouse

    Davis, Lori A.; Wagner, Tyler

    2016-01-01

    Sympatric populations of native Brook Trout Salvelinus fontinalis and naturalized Brown Trout Salmo truttaexist throughout the eastern USA. An understanding of habitat use by sympatric populations is of importance for fisheries management agencies because of the close association between habitat and population dynamics. Moreover, habitat use by stream-dwelling salmonids may be further complicated by several factors, including the potential for fish to display scale-dependent habitat use. Discrete-choice models were used to (1) evaluate fall and early winter daytime habitat use by sympatric Brook Trout and Brown Trout populations based on available residual pool habitat within a stream network and (2) assess the sensitivity of inferred habitat use to changes in the spatial scale of the assumed available habitat. Trout exhibited an overall preference for pool habitats over nonpool habitats; however, the use of pools was nonlinear over time. Brook Trout displayed a greater preference for deep residual pool habitats than for shallow pool and nonpool habitats, whereas Brown Trout selected for all pool habitat categories similarly. Habitat use by both species was found to be scale dependent. At the smallest spatial scale (50 m), habitat use was primarily related to the time of year and fish weight. However, at larger spatial scales (250 and 450 m), habitat use varied over time according to the study stream in which a fish was located. Scale-dependent relationships in seasonal habitat use by Brook Trout and Brown Trout highlight the importance of considering scale when attempting to make inferences about habitat use; fisheries managers may want to consider identifying the appropriate spatial scale when devising actions to restore and protect Brook Trout populations and their habitats.

  3. Spatial variation in density and size structure indicate habitat selection throughout life stages of two Southwestern Atlantic snappers.

    PubMed

    Aschenbrenner, Alexandre; Hackradt, Carlos Werner; Ferreira, Beatrice Padovani

    2016-02-01

    The early life history of Lutjanus alexandrei and Lutjanus jocu in Southwestern Atlantic is still largely unknown. Habitat use of different life stages (i.e. size categories and densities) of the Brazilian snapper (L. alexandrei) and dog snapper (L. jocu) was examined in a tropical portion of NE coast of Brazil. Visual surveys were conducted in different shallow habitats (mangroves and reefs). Both snapper species showed higher densities in early life stages in mangrove habitat, with a clear increase in fish size from mangrove to adjacent reefs. Post-settler individuals were exclusively found in mangroves for both species. Juveniles of L. alexandrei were also registered only in mangroves, while sub-adult individuals were associated with both mangrove and reef habitats. Mature individuals of L. alexandrei were only observed in reef habitats. Juvenile and sub-adult individuals of the dog snapper were both associated with mangrove and reef habitats, with high densities registered in mangroves. Mature individuals of L. jocu were not registered in the study area. This pattern suggests preference for mangrove habitat in early life stages for both species. Ontogenetic movement between habitats was also recorded. This pattern denotes habitat selection across different life cycle of both species. Such information highlights the importance of directing management and conservation efforts to these habitats to secure the continuity of contribution to adult populations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat

    NASA Technical Reports Server (NTRS)

    Howe, Alan; Kennedy, Kriss J.; Gill, Tracy R.; Tri, Terry O.; Toups, Larry; Howard, Robert I.; Spexarth, Gary R.; Cavanaugh, Stephen; Langford, William M.; Dorsey, John T.

    2014-01-01

    NASA's Constellation Architecture Team defined an outpost scenario optimized for intensive mobility that uses small, highly mobile pressurized rovers supported by portable habitat modules that can be carried between locations of interest on the lunar surface. A compact vertical cylinder characterizes the habitat concept, where the large diameter maximizes usable flat floor area optimized for a gravity environment and allows for efficient internal layout. The module was sized to fit into payload fairings for the Constellation Ares V launch vehicle, and optimized for surface transport carried by the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) mobility system. Launch and other loads are carried through the barrel to a top and bottom truss that interfaces with a structural support unit (SSU). The SSU contains self-leveling feet and docking interfaces for Tri-ATHLETE grasping and heavy lift. A pressurized module needed to be created that was appropriate for the lunar environment, could be easily relocated to new locations, and could be docked together in multiples for expanding pressurized volume in a lunar outpost. It was determined that horizontally oriented pressure vessels did not optimize floor area, which takes advantage of the gravity vector for full use. Hybrid hard-inflatable habitats added an unproven degree of complexity that may eventually be worked out. Other versions of vertically oriented pressure vessels were either too big, bulky, or did not optimize floor area. The purpose of the HDU vertical habitat module is to provide pressurized units that can be docked together in a modular way for lunar outpost pressurized volume expansion, and allow for other vehicles, rovers, and modules to be attached to the outpost to allow for IVA (intra-vehicular activity) transfer between them. The module is a vertically oriented cylinder with a large radius to allow for maximal floor area and use of volume. The modular, 5- m-diameter HDU vertical habitat

  5. MEGAEPIFAUNA-HABITAT RELATIONSHIPS IN YAQUINA BAY, OR

    EPA Science Inventory

    Habitat-based ecological risk assessments rely, in part, on estimates of the ecological value of the habitats at risk. As part of a larger programmatic effort to estimate estuarine habitat values, we determined megaepifauna-habitat relationships for four major intertidal habitat...

  6. Relations between habitat variability and population dynamics of bass in the Huron River, Michigan

    USGS Publications Warehouse

    Bovee, Ken D.; Newcomb, Tammy J.; Coon, Thomas G.

    1994-01-01

    One of the assumption of the Instream Flow Incremental Methodology (IFIM) is that the dynamics of fish populations are directly or indirectly related to habitat availability. Because this assumption has not been successfully tested in coolwater streams, questions arise regarding the validity of the methodology in such streams. The purpose of our study was to determine whether relations existed between habitat availability and population dynamics of smallmouth bass (Micropterus dolomieu) and rock bass (Ambloplites rupestris) in a 16-km reach of the Huron River in southeastern Michigan. Both species exhibited strong to moderate carryover of year classes from age 0 through age 2, indicating that adult populations were related to factors affecting recruitment. Year-class strength and subsequent numbers of yearling bass were related to the availability of young-of-year habitat during the first growing season for a cohort. Number of age-0, age-1, and adult smallmouth bass were related to the average length at age 0 for the cohort. Length at age 0 was associated with young-of-year habitat and thermal regime during the first growing season. Rock bass populations exhibited similar associations among age classes and habitat variables. Compared to smallmouth bass, the number of age-2 rock bass was associated more closely with their length at age 0 than with year-class strength. Length at age 0 and year-class strength of rock bass were associated with the same habitat variables as those related to age-0 smallmouth bass. We hypothesize that an energetic mechanism linked thermal regime to length at age 0 and that increased growth resulted in higher survival rates from age 0 to age 1. We also postulate that young-of-year habitat provided protection from predators, higher production of food resources, and increased foraging efficiency. We conclude that the IFIM is a valid methodology for instream flow investigations of coolwater streams. The results for our study support the

  7. Pupal habitat productivity of Anopheles gambiae complex mosquitoes in a rural village in western Kenya.

    PubMed

    Mutuku, Francis M; Bayoh, M Nabie; Gimnig, John E; Vulule, John M; Kamau, Luna; Walker, Edward D; Kabiru, Ephantus; Hawley, William A

    2006-01-01

    The productivity of larval habitats of the malaria vector Anopheles gambiae for pupae (the stage preceding adult metamorphosis) is poorly known, yet adult emergence from habitats is the primary determinant of vector density. To assess it, we used absolute sampling methods in four studies involving daily sampling for 25 days in 6 habitat types in a village in western Kenya. Anopheles gambiae s.s. comprised 82.5% of emergent adults and Anopheles arabiensis the remainder. Pupal production occurred from a subset of habitats, primarily soil burrow pits, and was discontinuous in time, even when larvae occupied all habitats continuously. Habitat stability was positively associated with pupal productivity. In a dry season, pupal productivity was distributed between burrow pits and pools in streambeds. Overall, these data support the notion that source reduction measures against recognizably productive habitats would be a useful component of an integrated management program for An. gambiae in villages.

  8. Habitat assessment of non-wadeable rivers in Michigan.

    PubMed

    Wilhelm, Jennifer G O; Allan, J David; Wessell, Kelly J; Merritt, Richard W; Cummins, Kenneth W

    2005-10-01

    Habitat evaluation of wadeable streams based on accepted protocols provides a rapid and widely used adjunct to biological assessment. However, little effort has been devoted to habitat evaluation in non-wadeable rivers, where it is likely that protocols will differ and field logistics will be more challenging. We developed and tested a non-wadeable habitat index (NWHI) for rivers of Michigan, where non-wadeable rivers were defined as those of order >or=5, drainage area >or=1600 km2, mainstem lengths >or=100 km, and mean annual discharge >or=15 m3/s. This identified 22 candidate rivers that ranged in length from 103 to 825 km and in drainage area from 1620 to 16,860 km2. We measured 171 individual habitat variables over 2-km reaches at 35 locations on 14 rivers during 2000-2002, where mean wetted width was found to range from 32 to 185 m and mean thalweg depth from 0.8 to 8.3 m. We used correlation and principal components analysis to reduce the number of variables, and examined the spatial pattern of retained variables to exclude any that appeared to reflect spatial location rather than reach condition, resulting in 12 variables to be considered in the habitat index. The proposed NWHI included seven variables: riparian width, large woody debris, aquatic vegetation, bottom deposition, bank stability, thalweg substrate, and off-channel habitat. These variables were included because of their statistical association with independently derived measures of human disturbance in the riparian zone and the catchment, and because they are considered important in other habitat protocols or to the ecology of large rivers. Five variables were excluded because they were primarily related to river size rather than anthropogenic disturbance. This index correlated strongly with indices of disturbance based on the riparian (adjusted R2 = 0.62) and the catchment (adjusted R2 = 0.50), and distinguished the 35 river reaches into the categories of poor (2), fair (19), good (13), and

  9. Expansion of oxygen minimum zones may reduce available habitat for tropical pelagic fishes

    NASA Astrophysics Data System (ADS)

    Stramma, Lothar; Prince, Eric D.; Schmidtko, Sunke; Luo, Jiangang; Hoolihan, John P.; Visbeck, Martin; Wallace, Douglas W. R.; Brandt, Peter; Körtzinger, Arne

    2012-01-01

    Climate model predictions and observations reveal regional declines in oceanic dissolved oxygen, which are probably influenced by global warming. Studies indicate ongoing dissolved oxygen depletion and vertical expansion of the oxygen minimum zone (OMZ) in the tropical northeast Atlantic Ocean. OMZ shoaling may restrict the usable habitat of billfishes and tunas to a narrow surface layer. We report a decrease in the upper ocean layer exceeding 3.5mll-1 dissolved oxygen at a rate of <=1myr-1 in the tropical northeast Atlantic (0-25°N, 12-30°W), amounting to an annual habitat loss of ~5.95×1013m3, or 15% for the period 1960-2010. Habitat compression and associated potential habitat loss was validated using electronic tagging data from 47 blue marlin. This phenomenon increases vulnerability to surface fishing gear for billfishes and tunas, and may be associated with a 10-50% worldwide decline of pelagic predator diversity. Further expansion of the Atlantic OMZ along with overfishing may threaten the sustainability of these valuable pelagic fisheries and marine ecosystems.

  10. Headwater Stream Management Dichotomies: Local Amphibian Habitat vs. Downstream Fish Habitat

    NASA Astrophysics Data System (ADS)

    Jackson, C. R.

    2002-12-01

    Small headwater streams in mountainous areas of the Pacific Northwest often do not harbor fish populations because of low water depth and high gradients. Rather, these streams provide habitat for dense assemblages of stream-dwelling amphibians. A variety of management goals have been suggested for such streams such as encouraging large woody debris recruitment to assist in sediment trapping and valley floor formation, encouraging large woody debris recruitment to provide downstream wood when debris flows occur, providing continuous linear stream buffers within forest harvest areas to provide shade and bank stability, etc. A basic problem with analying the geomorphic or biotic benefits of any of these strategies is the lack of explicit management goals for such streams. Should managers strive to optimize downstream fish habitat, local amphibian habitat, or both? Through observational data and theoretical considerations, it will be shown that these biotic goals will lead to very different geomorphic management recommendations. For instance, woody debris greater than 60 cm diameter may assist in valley floor development, but it is likely to create subsurface channel flow of unknown value to amphibians. Trapping and retention of fine sediments within headwater streams may improve downstream spawning gravels, but degrades stream-dwelling amphibian habitat. In response to the need for descriptive information on habitat and channel morphology specific to small, non-fish-bearing streams in the Pacific Northwest, morphologies and wood frequencies in forty-two first- and second-order forested streams less than four meters wide were surveyed. Frequencies and size distributions of woody debris were compared between small streams and larger fish-bearing streams as well as between second-growth and virgin timber streams. Statistical models were developed to explore dominant factors affecting channel morphology and habitat. Findings suggest geomorphological relationships

  11. Habitat Suitability Index Models: Eastern meadowlark

    USGS Publications Warehouse

    Schroeder, Richard L.; Sousa, Patrick J.

    1982-01-01

    Habitat preferences of the eastern meadowlark (Sturnella magna) are described in this publication, which is one of a series of Habitat Suitability Index (HSI) models. Habitat use information is presented in a synthesis of the literature on the species-habitat requirements of the eastern meadowlark, followed by the development of the HSI model. The model is presented in three formats: graphic, word, and mathematical, and is designed to provide information for use in impact assessment and habitat management activities.

  12. Habitat Suitability Index Models: Pine warbler

    USGS Publications Warehouse

    Schroeder, Richard L.

    1982-01-01

    Habitat preferences of the pine warbler (Dendroica pinus) are described in this publication, which is one of a series of Habitat Suitability Index (HSI) models. Habitat use information is presented in a synthesis of the literature on the species-habitat requirements of the pine warbler, followed by the development of the HSI model. The model is presented in three formats: graphic, word, and mathematical, and is designed to provide information for use in impact assessment and habitat management activities.

  13. Habitat planning, maintenance and management working group

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

    NONE

    The Gulf of Mexico (GOM), called {open_quotes}America`s Sea,{close_quotes} is actually a small ocean basin covering over 1.5 million square kilometers. Because of the multiple uses, diversity, and size of the Gulf`s resources, management is shared by a number of governmental agencies including the Minerals Management Service, the Gulf of Mexico Fishery Management Council, the Gulf States Marine Fisheries Commission, National Marine Fisheries Service, the US Coast Guard, the US Army Corps of Engineers, and the five Gulf states fisheries agencies. All of these entities share a common goal of achieving optimum sustainable yield to maximize geological, biological, social, and economicmore » benefits from these resources. These entities also share a common theme that the successful management of the northern GOM requires maintenance and enhancement of both the quantity and quality of habitats. A closer look at the GOM shows the sediment to be clearly dominated by vast sand and mud plains. These soft bottom habitats are preferred by many groundfish and shrimp species and, thus, have given rise to large commercial fisheries on these stocks. Hard bottom and reef habitats, on the other hand, are limited to approximately 1.6% of the total area of the Gulf, so that, while there are high demands by commercial and recreational fishermen for reef associated species, the availability of habitat for these stocks is limited. The thousands of oil and gas structures placed in the Gulf have added significant amounts of new hard substrate. The rigs-to-reefs concept was a common sense idea with support from environmental user groups and the petroleum industry for preserving a limited but valuable habitat type. As long as maximizing long-term benefits from the Gulf s resources for the greatest number of users remains the goal, then programs such as Rigs-to-Reefs will remain an important tool for fisheries and habitat managers in the Gulf.« less

  14. Environment degeneration affects habitat diversity of Tamarix spp. in arid zone

    NASA Astrophysics Data System (ADS)

    Li, Tiejun; Yang, Weikang

    2003-07-01

    There are 18 species of Tamarix spp. in China and 16 of them in Xinjiang. As a group of bushes which widespread in salty and sandy land in arid zone, Tamarix spp. had gotten more and more attention by ecologists because of their unique bio-ecological characteristics, ecological and social economy functions. Wide Distribution of Tamarix spp. affects ecological environment stabilization of arid zone in western China. The modern distribution and habitat of Tamarix spp. diversity in Xinjiang were studied in this paper. Result revealed that water (surface water and high groundwater ) is the critical environment factor which determines the modern distribution of Tamarix spp.. Depend on analyzing groundwater lever and salt content of soil(two environment factors), author divided the habitat of Tamarix spp. into six type groups (low salt type with high groundwater, middle salt type with high groundwater, high salt type with high groundwater, low salt type with low groundwater and middle salt type with low groundwater etc.) which consisting of ten habitat types. Habitat of Tamarix spp. in Xinjiang never exists in isolation, but associate with each other. The groundwater lever and salt content of soil varies with the lapse of time, then habitats transform from one type into another and species of Tamarix spp. in habitats transforms accordingly.

  15. New England wildlife: management forested habitats

    Treesearch

    Richard M. DeGraaf; Mariko Yamasaki; William B. Leak; John W. Lanier

    1992-01-01

    Presents silvicultural treatments for six major cover-type groups in New England to produce stand conditions that provide habitat opportunities for a wide range of wildlife species. Includes matrices for species occurrence and utilization by forested and nonforested habitats, habitat breadth and size class, and structural habitat features for the 338 wildlife species...

  16. Factors influencing behavior and transferability of habitat models for a benthic stream fish

    Treesearch

    Kevin N. Leftwich; Paul L. Angermeier; C. Andrew Dolloff

    1997-01-01

    The authors examined the predictive power and transferability of habitat-based models by comparing associations of tangerine darter Percina aurantiaca and stream habitat at local and regional scales in North Fork Holston River (NFHR) and Little River, VA. The models correctly predicted the presence or absence of tangerine darters in NFHR for 64 percent (local model)...

  17. Challenges in rendering Coral Triangle habitat richness in remotely sensed habitat maps: The case of Bunaken Island (Indonesia).

    PubMed

    Ampou, Eghbert Elvan; Ouillon, Sylvain; Andréfouët, Serge

    2018-06-01

    The Coral Triangle is the epicenter of marine biodiversity, yet the numbers of habitats that can be found on coral reefs remain poorly described. First surveys for habitat mapping in Indonesia revealed a high number of habitats (>150) even for structurally simple reefs. To be able to represent all these habitats, typical habitat mapping procedures and performances are poorly effective even using very high resolution satellite images. Using Bunaken Island (North Sulawesi, Indonesia) as a case study, we devised a way to maintain all the in situ habitat information in remote sensing habitat map products without loss and with mapping procedures based on photo-interpretation. The result is a product which is consistent with a per-polygon fuzzy classification. As such, it is a complex product that meets our habitat representation goal, but its complexity can also limit its immediate use by managers and conservation planners when analyses per habitat are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Sedimentary facies, geomorphic features and habitat distribution at the Hudson Canyon head from AUV multibeam data

    NASA Astrophysics Data System (ADS)

    Pierdomenico, Martina; Guida, Vincent G.; Macelloni, Leonardo; Chiocci, Francesco L.; Rona, Peter A.; Scranton, Mary I.; Asper, Vernon; Diercks, Arne

    2015-11-01

    Mapping of physical benthic habitats at the head of Hudson Canyon was performed by means of integrated analysis of acoustic data, video surveys and seafloor sampling. Acoustic mapping, performed using AUV-mounted multibeam sonar, provided ultra-high resolution bathymetric and backscatter imagery for the identification of geomorphological features and the characterization of surficial sediments. Habitat characterization in terms of seafloor texture and identification of benthic and demersal communities was accomplished by visual analysis of still photographs from underwater vehicles. Habitat classes were defined on the basis of the seafloor texture observed on photos and then compared with the geophysical data in order to associate habitats to acoustic classes and/or geomorphological features. This enabled us to infer habitat distribution on the basis of morpho-acoustic classes and extrapolate results over larger areas. Results from bottom trawling were used to determine the overall biodiversity within the identified habitats. Our analysis revealed a variety of topographic and sedimentological structures that provide a wide range of physical habitats. A variety of sandy and muddy substrates, gravel patches and mudstone outcrops host rich and varied faunal assemblages, including cold-water corals and sponge communities. Pockmark fields below 300 m depth suggest that methane-based chemosynthetic carbonate deposition may contributes to creation of specific benthic habitats. Hummocky terrain has been delineated along the canyon rims and associated with extensive, long-term burrowing activity by golden tilefish (Lopholatilus chamaeleonticeps). These results show the relationships of physical features to benthic habitat variation, support the notion of the area as a biodiversity hotspot and define essential habitats for planning of sustainable regional fisheries.

  19. Habitat modeling and genetic signatures of postglacial recolonization for tidal estuaries

    NASA Astrophysics Data System (ADS)

    Dolby, G. A.; Jacobs, D. K.

    2014-12-01

    Pleistocene glacial cycles are a foremost influence on the genetic diversity and species distribution patterns observed today. Though much work has centered on biotic response to such climatic forcing, little of it has regarded estuarine or other aquatic coastal taxa whose habitat formation is a function of sea level, hydrography, and coastal geomorphology. These physical parameters required for habitat formation suggest that glacial cycles impart a significant effect on such taxa through glacially driven eustatic changes. Additionally, the steepened coastline and rainfall-limited Mediterranean climate suggest limited glacial habitat for estuarine species in southern and Baja California. Here we present GIS modeled habitat for tidal estuaries for three co-distributed estuarine fishes (Gillichthys mirabilis, Quietula y-cauda, Fundulus parvipinnis) since the last glacial maximum. Parameterization of sea level and slope enables biologically relevant temporal resolution of near-millennial scale. At lowstand our approach reveals two refuges along the coast at 1000km distance from each other, with habitat rapidly increasing 15 - 12 ka during meltwater pulse 1A. Habitat area peaked in the early Holocene and began decreasing with the current stillstand roughly 7 ka, probably as a result of coastal maturation towards less tidal systems. To target the postglacial recolonization process we applied discriminant function analysis to highly polymorphic microsatellite data to partition out the alleles associated with refuges identified a priori by habitat modeling. The frequencies of these alleles were calculated for all individuals at intervening populations and regressed against geographic distance. This analysis revealed nonlinear mixing curves, suggesting uneven allelic mixing efficiency along the coastline, perhaps as a result of differential habitat origination times as indicated by the habitat models. These results highlight the dynamism of estuarine habitat in recent

  20. Multivariate model of female black bear habitat use for a Geographic Information System

    USGS Publications Warehouse

    Clark, Joseph D.; Dunn, James E.; Smith, Kimberly G.

    1993-01-01

    Simple univariate statistical techniques may not adequately assess the multidimensional nature of habitats used by wildlife. Thus, we developed a multivariate method to model habitat-use potential using a set of female black bear (Ursus americanus) radio locations and habitat data consisting of forest cover type, elevation, slope, aspect, distance to roads, distance to streams, and forest cover type diversity score in the Ozark Mountains of Arkansas. The model is based on the Mahalanobis distance statistic coupled with Geographic Information System (GIS) technology. That statistic is a measure of dissimilarity and represents a standardized squared distance between a set of sample variates and an ideal based on the mean of variates associated with animal observations. Calculations were made with the GIS to produce a map containing Mahalanobis distance values within each cell on a 60- × 60-m grid. The model identified areas of high habitat use potential that could not otherwise be identified by independent perusal of any single map layer. This technique avoids many pitfalls that commonly affect typical multivariate analyses of habitat use and is a useful tool for habitat manipulation or mitigation to favor terrestrial vertebrates that use habitats on a landscape scale.

  1. Habitats of North American sea ducks.

    USGS Publications Warehouse

    Derksen, Dirk V.; Petersen, Margaret R.; Savard, Jean-Pierre L.

    2015-01-01

    Breeding, molting, fall and spring staging, and wintering habitats of the sea duck tribe Mergini are described based on geographic locations and distribution in North America, geomorphology, vegetation and soil types, and fresh water and marine characteristics. The dynamics of habitats are discussed in light of natural and anthropogenic events that shape areas important to sea ducks. Strategies for sea duck habitat management are outlined and recommendations for international collaboration to preserve key terrestrial and aquatic habitats are advanced. We follow the definition of habitat advanced by Odum (1971), which is the place or space where an organism lives. Weller (1999) emphasized that habitats for waterbirds required presence of sufficient resources (i.e., food, water, cover, space) for maintenance during a portion of their annual cycle. Habitats exploited by North American sea ducks are diverse, widespread across the continent and adjacent marine waters and until recently, most were only superficially known. A 15-year-long effort funded research on sea duck habitats through the Sea Duck Joint Venture and the Endangered or Threatened Species programs of the United States and Canada. Nevertheless, important gaps remain in our understanding of key elements required by some species during various life stages. Many significant habitats, especially staging and wintering sites, have been and continue to be destroyed or altered by anthropogenic activities. The goal of this chapter is to develop a comprehensive summary of marine, freshwater, and terrestrial habitats and their characteristics by considering sea duck species with similar needs as groups within the tribe Mergini. Additionally, we examine threats and changes to sea duck habitats from human-caused and natural events. Last, we evaluate conservation and management programs underway or available for maintenance and enhancement of habitats critical for sea ducks.

  2. Wildlife habitat considerations

    Treesearch

    Helen Y. Smith

    2000-01-01

    Fire, insects, disease, harvesting, and precommercial thinning all create mosaics on Northern Rocky Mountain landscapes. These mosaics are important for faunal habitat. Consequently, changes such as created openings or an increase in heavily stocked areas affect the water, cover, and food of forest habitats. The “no action” alternative in ecosystem management of low...

  3. Habitat heterogeneity and associated microbial community structure in a small-scale floodplain hyporheic flow path.

    PubMed

    Lowell, Jennifer L; Gordon, Nathan; Engstrom, Dale; Stanford, Jack A; Holben, William E; Gannon, James E

    2009-10-01

    The Nyack floodplain is located on the Middle Fork of the Flathead River, an unregulated, pristine, fifth-order stream in Montana, USA, bordering Glacier National Park. The hyporheic zone is a nutritionally heterogeneous floodplain component harboring a diverse array of microbial assemblages essential in fluvial biogeochemical cycling, riverine ecosystem productivity, and trophic interactions. Despite these functions, microbial community structure in pristine hyporheic systems is not well characterized. The current study was designed to assess whether physical habitat heterogeneity within the hyporheic zone of the Nyack floodplain was sufficient to drive bacterial beta diversity between three different hyporheic flow path locations. Habitat heterogeneity was assessed by measuring soluble reactive phosphorous, nitrate, dissolved organic carbon, dissolved oxygen, and soluble total nitrogen levels seasonally at surface water infiltration, advection, and exfiltration zones. Significant spatial differences were detected in dissolved oxygen and nitrate levels, and seasonal differences were detected in dissolved oxygen, nitrate, and dissolved organic carbon levels. Denaturing gradient gel electrophoresis (DGGE) and cell counts indicated that bacterial diversity increased with abundance, and DGGE fingerprints covaried with nitrate levels where water infiltrated the hyporheic zone. The ribosomal gene phylogeny revealed that hyporheic habitat heterogeneity was sufficient to drive beta diversity between bacterial assemblages. Phylogenetic (P) tests detected sequence disparity between the flow path locations. Small distinct lineages of Firmicutes, Actinomycetes, Planctomycetes, and Acidobacteria defined the infiltration zone and alpha- and beta-proteobacterial lineages delineated the exfiltration and advection zone communities. These data suggest that spatial habitat heterogeneity drives hyporheic microbial community development and that attempts to understand functional

  4. Assessing critical habitat: Evaluating the relative contribution of habitats to population persistence

    EPA Science Inventory

    1. A principal challenge of species conservation is to identify the specific habitats that are essential for long-term persistence or recovery of species at risk. However, many commonly used approaches to identifying important habitats do not provide direct insight into the contr...

  5. Genetic diversity in butterflies: Interactive effects of habitat fragmentation and climate-driven range expansion.

    PubMed

    Hill, Jane K; Hughes, Clare L; Dytham, Calvin; Searle, Jeremy B

    2006-03-22

    Some species are expanding their ranges polewards during current climate warming. However, anthropogenic fragmentation of suitable habitat is affecting expansion rates and here we investigate interactions between range expansion, habitat fragmentation and genetic diversity. We examined three closely related Satyrinae butterflies, which differ in their habitat associations, from six sites along a transect in England from distribution core to expanding range margin. There was a significant decline in allozyme variation towards an expanding range margin in Pararge aegeria, which has the most restricted habitat availability, but not in Pyronia tithonus whose habitat is more widely available, or in a non-expanding 'control species' (Maniola jurtina). Moreover, data from another transect in Scotland indicated that declines in genetic diversity in P. aegeria were evident only on the transect in England, which had greater habitat fragmentation. Our results indicate that fragmentation of breeding habitats leads to more severe founder events during colonization, resulting in reduced diversity in marginal populations in more specialist species. The continued widespread loss of suitable habitats in the future may increase the likelihood of loss of genetic diversity in expanding species, which may affect whether or not species can adapt to future environmental change.

  6. Sound solutions for habitat monitoring

    Treesearch

    Mary M. Rowland; Lowell H. Suring; Christina D. Vojta

    2015-01-01

    For agencies and organizations to effectively manage wildlife, knowledge about the status and trend of wildlife habitat is critical. Traditional wildlife monitoring, however, has focused on populations rather than habitat, because ultimately population status drives long-term species viability. Still, habitat loss has contributed to the decline of nearly all at-risk...

  7. Biodiversity and Habitat Markets—Policy, Economic, and Ecological implications of Market-Based Conservation

    USGS Publications Warehouse

    Pindilli, Emily J.; Casey, Frank

    2015-10-26

    This report is a primer on market-like and market-based mechanisms designed to conserve biodiversity and habitat. The types of markets and market-based approaches that were implemented or are emerging to benefit biodiversity and habitat in the United States are examined. The central approaches considered in this report include payments for ecosystem services, conservation banks, habitat exchanges, and eco-labels. Based on literature reviews and input from experts and practitioners, the report characterizes each market-based approach including policy context and structure; the theoretical basis for applying market-based approaches; the ecological effectiveness of practices and tools for measuring performance; and the future outlook for biodiversity and habitat markets. This report draws from previous research and serves as a summary of pertinent information associated with biodiversity and habitat markets while providing references to materials that go into greater detail on specific topics.

  8. Projected changes in wildlife habitats in Arctic natural areas of northwest Alaska

    USGS Publications Warehouse

    Marcot, Bruce G.; Jorgenson, M. Torre; Lawler, James P.; Handel, Colleen M.; DeGange, Anthony R.

    2015-01-01

    We project the effects of transitional changes among 60 vegetation and other land cover types (“ecotypes”) in northwest Alaska over the 21st century on habitats of 162 bird and 39 mammal species known or expected to occur regularly in the region. This analysis, encompassing a broad suite of arctic and boreal wildlife species, entailed building wildlife-habitat matrices denoting levels of use of each ecotype by each species, and projecting habitat changes under historic and expected accelerated future rates of change from increasing mean annual air temperature based on the average of 5 global climate models under the A1B emissions scenario, and from potential influence of a set of 23 biophysical drivers. Under historic rates of change, we project that 52 % of the 201 species will experience an increase in medium- and high-use habitats, 3 % no change, and 45 % a decrease, and that a greater proportion of mammal species (62 %) will experience habitat declines than will bird species (50 %). Outcomes become more dire (more species showing habitat loss) under projections made from effects of biophysical drivers and especially from increasing temperature, although species generally associated with increasing shrub and tree ecotypes will likely increase in distribution. Changes in wildlife habitats likely will also affect trophic cascades, ecosystem function, and ecosystem services; of particular significance are the projected declines in habitats of most small mammals that form the prey base for mesocarnivores and raptors, and habitat declines in 25 of the 50 bird and mammal species used for subsistence hunting and trapping.

  9. Habitat Effects on the Breeding Performance of Three Forest-Dwelling Hawks.

    PubMed

    Björklund, Heidi; Valkama, Jari; Tomppo, Erkki; Laaksonen, Toni

    2015-01-01

    Habitat loss causes population declines, but the mechanisms are rarely known. In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance. We studied the boreal breeding habitat and habitat-associated breeding performance of the northern goshawk (Accipiter gentilis), common buzzard (Buteo buteo) and European honey buzzard (Pernis apivorus). We combined long-term Finnish bird-of-prey data with multi-source national forest inventory data at various distances (100-4000 m) around the hawk nests. We found that breeding success of the goshawk was best explained by the habitat within a 2000-m radius around the nests; breeding was more successful with increasing proportions of old spruce forest and water, and decreasing proportions of young thinning forest. None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species. The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992-2010. In contrast, the area of young forest increased in southern Finland but not around hawk nests. We emphasize the importance of studying habitats at several spatial and temporal scales to determine the relevant species-specific scale and to detect environmental changes. Further effort is needed to reconcile the socioeconomic and ecological functions of forests and habitat requirements of old forest specialists.

  10. Habitat use by fishes of Lake Superior. II. Consequences of diel habitat use for habitat linkages and habitat coupling in nearshore and offshore waters

    USGS Publications Warehouse

    Gorman, Owen T.; Yule, Daniel L.; Stockwell, Jason D.

    2012-01-01

    Diel migration patterns of fishes in nearshore (15–80 m depth) and offshore (>80 m) waters of Lake Superior were examined to assess the potential for diel migration to link benthic and pelagic, and nearshore and offshore habitats. In our companion article, we described three types of diel migration: diel vertical migration (DVM), diel bank migration (DBM), and no diel migration. DVM was expressed by fishes migrating from benthopelagic to pelagic positions and DBM was expressed by fishes migrating horizontally from deep to shallow waters at night. Fishes not exhibiting diel migration typically showed increased activity by moving from benthic to benthopelagic positions within demersal habitat. The distribution and biomass of fishes in Lake Superior was characterized by examining 704 bottom trawl samples collected between 2001 and 2008 from four depth zones: ≤40, 41–80, 81–160, and >160 m. Diel migration behaviors of fishes described in our companion article were applied to estimates of areal biomass (kg ha−1) for each species by depth zone. The relative strength of diel migrations were assessed by applying lake area to areal biomass estimates for each species by depth zone to yield estimates of lake-wide biomass (metric tonnes). Overall, species expressing DVM accounted for 83%, DBM 6%, and non-migration 11% of the total lake-wide community biomass. In nearshore waters, species expressing DVM represented 74% of the biomass, DBM 25%, and non-migration 1%. In offshore waters, species expressing DVM represented 85%, DBM 1%, and non-migration 14% of the biomass. Of species expressing DVM, 83% of total biomass occurred in offshore waters. Similarly, 97% of biomass of non-migrators occurred in offshore waters while 83% of biomass of species expressing DBM occurred in nearshore waters. A high correlation (R2 = 0.996) between lake area and community biomass by depth zone resulted in 81% of the lake-wide biomass occurring in offshore waters. Accentuating this

  11. Habitat Heterogeneity Variably Influences Habitat Selection by Wild Herbivores in a Semi-Arid Tropical Savanna Ecosystem

    PubMed Central

    Muposhi, Victor K.; Gandiwa, Edson; Chemura, Abel; Bartels, Paul; Makuza, Stanley M.; Madiri, Tinaapi H.

    2016-01-01

    An understanding of the habitat selection patterns by wild herbivores is critical for adaptive management, particularly towards ecosystem management and wildlife conservation in semi arid savanna ecosystems. We tested the following predictions: (i) surface water availability, habitat quality and human presence have a strong influence on the spatial distribution of wild herbivores in the dry season, (ii) habitat suitability for large herbivores would be higher compared to medium-sized herbivores in the dry season, and (iii) spatial extent of suitable habitats for wild herbivores will be different between years, i.e., 2006 and 2010, in Matetsi Safari Area, Zimbabwe. MaxEnt modeling was done to determine the habitat suitability of large herbivores and medium-sized herbivores. MaxEnt modeling of habitat suitability for large herbivores using the environmental variables was successful for the selected species in 2006 and 2010, except for elephant (Loxodonta africana) for the year 2010. Overall, large herbivores probability of occurrence was mostly influenced by distance from rivers. Distance from roads influenced much of the variability in the probability of occurrence of medium-sized herbivores. The overall predicted area for large and medium-sized herbivores was not different. Large herbivores may not necessarily utilize larger habitat patches over medium-sized herbivores due to the habitat homogenizing effect of water provisioning. Effect of surface water availability, proximity to riverine ecosystems and roads on habitat suitability of large and medium-sized herbivores in the dry season was highly variable thus could change from one year to another. We recommend adaptive management initiatives aimed at ensuring dynamic water supply in protected areas through temporal closure and or opening of water points to promote heterogeneity of wildlife habitats. PMID:27680673

  12. Commercially important species associated with horse mussel (Modiolus modiolus) biogenic reefs: A priority habitat for nature conservation and fisheries benefits.

    PubMed

    Kent, Flora E A; Mair, James M; Newton, Jason; Lindenbaum, Charles; Porter, Joanne S; Sanderson, William G

    2017-05-15

    Horse mussel reefs (Modiolus modiolus) are biodiversity hotspots afforded protection by Marine Protected Areas (MPAs) in the NE Atlantic. In this study, horse mussel reefs, cobble habitats and sandy habitats were assessed using underwater visual census and drop-down video techniques in three UK regions. Megafauna were enumerated, differences in community composition and individual species abundances were analysed. Samples of conspicuous megafauna were also collected from horse mussel reefs in Orkney for stable isotope analysis. Communities of conspicuous megafauna were different between horse mussel habitats and other habitats throughout their range. Three commercially important species: whelks (Buccinum undatum), queen scallops (Aequipecten opercularis) and spider crabs (Maja brachydactyla) were significantly more abundant (by as much as 20 times) on horse mussel reefs than elsewhere. Isotopic analysis provided insights into their trophic relationship with the horse mussel reef. Protection of M. modiolus habitat can achieve biodiversity conservation objectives whilst benefiting fisheries also. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Three-dimensional habitat structure and landscape genetics: a step forward in estimating functional connectivity.

    PubMed

    Milanesi, P; Holderegger, R; Bollmann, K; Gugerli, F; Zellweger, F

    2017-02-01

    Estimating connectivity among fragmented habitat patches is crucial for evaluating the functionality of ecological networks. However, current estimates of landscape resistance to animal movement and dispersal lack landscape-level data on local habitat structure. Here, we used a landscape genetics approach to show that high-fidelity habitat structure maps derived from Light Detection and Ranging (LiDAR) data critically improve functional connectivity estimates compared to conventional land cover data. We related pairwise genetic distances of 128 Capercaillie (Tetrao urogallus) genotypes to least-cost path distances at multiple scales derived from land cover data. Resulting β values of linear mixed effects models ranged from 0.372 to 0.495, while those derived from LiDAR ranged from 0.558 to 0.758. The identification and conservation of functional ecological networks suffering from habitat fragmentation and homogenization will thus benefit from the growing availability of detailed and contiguous data on three-dimensional habitat structure and associated habitat quality. © 2016 by the Ecological Society of America.

  14. [Effects of habitat fragmentation on nesting site selection of red-crowned crane].

    PubMed

    Wan, Dongmei; Gao, Wei; Wang, Qiuyu; Wang, Haitao; Liu, Mingyu

    2002-05-01

    During April and May of 1985, 1995 and 1998, red-crowned crane's nesting and variation of breeding population quantities in Shuangtaihekou National Natural Reserve in Liaoning, and also the habitat fragmentation there were investigated. Associated with previous data of the reserve, red-crowned crane's nesting habitat had been seriously fragmentated into 91 patches from one integrated reed wetland. The area of the smallest patch was 0.37 km2, and the minimum distance of two nests was 304 m. Compared with records of previous data, the minimum area of nesting habitat reduced by 0.72 km2. However, the breeding population quantities of red-crowned crane had maintained at about 30 pairs for a long period. The red-crowned crane adapted to the changed environment by the ecological adaptation strategy of reducing area of nesting habitat.

  15. MODELING PHYSICAL HABITAT PARAMETERS

    EPA Science Inventory

    Salmonid populations can be affected by alterations in stream physical habitat. Fish productivity is determined by the stream's physical habitat structure ( channel form, substrate distribution, riparian vegetation), water quality, flow regime and inputs from the watershed (sedim...

  16. Indicators: Physical Habitat Complexity

    EPA Pesticide Factsheets

    Physical habitat complexity measures the amount and variety of all types of cove at the water’s edge in lakes. In general, dense and varied shoreline habitat is able to support more diverse communities of aquatic life.

  17. Seafloor habitat mapping of the New York Bight incorporating sidescan sonar data

    USGS Publications Warehouse

    Lathrop, R.G.; Cole, M.; Senyk, N.; Butman, B.

    2006-01-01

    The efficacy of using sidescan sonar imagery, image classification algorithms and geographic information system (GIS) techniques to characterize the seafloor bottom of the New York Bight were assessed. The resulting seafloor bottom type map was compared with fish trawl survey data to determine whether there were any discernable habitat associations. An unsupervised classification with 20 spectral classes was produced using the sidescan sonar imagery, bathymetry and secondarily derived spatial heterogeneity to characterize homogenous regions within the study area. The spectral classes, geologic interpretations of the study region, bathymetry and a bottom landform index were used to produce a seafloor bottom type map of 9 different bottom types. Examination of sediment sample data by bottom type indicated that each bottom type class had a distinct composition of sediments. Analysis of adult summer flounder, Paralichthys dentatus, and adult silver hake, Merluccius bilinearis, presence/absence data from trawl surveys did not show evidence of strong associations between the species distributions and seafloor bottom type. However, the absence of strong habitat associations may be more attributable to the coarse scale and geographic uncertainty of the trawl sampling data than conclusive evidence that no habitat associations exist for these two species. ?? 2006 Elsevier Ltd. All rights reserved.

  18. Songbirds are resilient to hurricane disturbed habitats during spring migration

    USGS Publications Warehouse

    Lain, Emily; Zenzal, Theodore J.; Moore, Frank R.; Barrow, Wylie C.; Diehl, Robert H.

    2017-01-01

    The Gulf of Mexico is a conspicuous feature of the Neotropical–Nearctic bird migration system. Traveling long distances across ecological barriers comes with considerable risks, and mortality associated with intercontinental migration may be substantial, including that caused by storms or other adverse weather events. However, little, if anything, is known about how migratory birds respond to disturbance-induced changes in stopover habitat. Isolated, forested cheniere habitat along the northern coast of the Gulf of Mexico often concentrate migrants, during weather conditions unfavorable for northward movement or when birds are energetically stressed. We expected hurricane induced degradation of this habitat to negatively affect the abundance, propensity to stopover, and fueling trends of songbirds that stopover in coastal habitat. We used spring banding data collected in coastal Louisiana to compare migrant abundance and fueling trends before (1993–1996 and 1998–2005) and after hurricanes Rita (2006) and Ike (2009). We also characterized changes in vegetative structure before (1995) and after (2010) the hurricanes. The hurricanes caused dramatic changes to the vegetative structure, which likely decreased resources. Surprisingly, abundance, propensity to stopover, and fueling trends of most migrant species were not influenced by hurricane disturbance. Our results suggest that: 1) the function of chenieres as a refuge for migrants after completing a trans-Gulf flight may not have changed despite significant changes to habitat and decreases in resource availability, and 2) that most migrants may be able to cope with habitat disturbance during stopover. The fact that migrants use disturbed habitat points to their conservation value along the northern coast of the Gulf of Mexico.

  19. Created versus natural coastal islands: Atlantic waterbird populations, habitat choices, and management implications

    USGS Publications Warehouse

    Erwin, R.M.; Allen, D.H.; Jenkins, D.

    2003-01-01

    Nesting colonial waterbirds along the Atlantic Coast of the United States face a number of landscape-level threats including human disturbance, mammalian predator expansion, and habitat alteration. There have been changes from 1977 to the mid-1990s in use of nesting habitats and populations of a number of seabird species of concern in the region, including black skimmers Rynchops niger Linnaeaus, common terns Sterna hirundo Linnaeaus, gull-billed terns Sterna nilotica Linnaeaus, least terns Sterna antillarum Lesson, royal terns Sterna maxima Boddaert, and sandwich terns Sterna sandvicensis Cabot. These species form colonies primarily on the following habitat types: large, sandy barrier or shoal islands, natural estuarine or bay islands (mostly marsh), man-made islands of dredged deposition materials (from navigation channels), and the mainland. Significant changes in the use of the dredged material islands have occurred for these species in New Jersey and North Carolina, but not in Virginia. Population declines and changes in bird habitat use appear to be at least partially associated with the conditions and management of the existing dredged material islands, coastal policy changes associated with creating new dredged material islands, and competing demands for sand for beach augmentation by coastal communities. As these and other coastal habitats become less suitable for colonial waterbirds, other manmade sites, such as bridges and buildings have become increasingly more important. In regions with intense recreational demands, coastal wildlife managers need to take a more aggressive role in managing natural and man-made habitats areas and as stakeholders in the decision-making process involving dredged materials and beach sand allocation.

  20. Habitat and landscape characteristics underlying anuran community structure along an urban-rural gradient.

    PubMed

    Pillsbury, Finn C; Miller, James R

    2008-07-01

    Urbanization has been cited as an important factor in worldwide amphibian declines, and although recent work has illustrated the important influence of broad-scale ecological patterns and processes on amphibian populations, little is known about the factors structuring amphibian communities in urban landscapes. We therefore examined amphibian community responses to wetland habitat availability and landscape characteristics along an urban-rural gradient in central Iowa, USA, a region experiencing rapid suburban growth. We conducted call surveys at 61 wetlands to estimate anuran calling activity, and quantified wetland habitat structure and landscape context. We used canonical correspondence analysis (CCA) to examine patterns in anuran community structure and identify the most important variables associated with those patterns. Urban density at the landscape scale had a significant negative influence on overall anuran abundance and diversity. While every species exhibited a decrease in abundance with increasing urban density, this pattern was especially pronounced for species requiring post-breeding upland habitats. Anurans most affected by urbanization were those associated with short hydroperiods, early breeding activity, and substantial upland habitat use. We suggest that broad-scale landscape fragmentation is an important factor underlying anuran community structure in this region, possibly due to limitations on the accessibility of otherwise suitable habitat in fragmented urban landscapes. This study underscores the importance of a regional approach to amphibian conservation in urban and urbanizing areas; in fragmented landscapes, a network of interconnected wetland and upland habitats may be more likely to support a successful, diverse anuran community than will isolated sites.

  1. Predictive Seagrass Habitat Model

    EPA Science Inventory

    Restoration of ecosystem services provided by seagrass habitats in estuaries requires a firm understanding of the modes of action of multiple interacting stressors including nutrients, climate change, coastal land-use change, and habitat modification. We explored the application...

  2. Habitat models to predict wetland bird occupancy influenced by scale, anthropogenic disturbance, and imperfect detection

    USGS Publications Warehouse

    Glisson, Wesley J.; Conway, Courtney J.; Nadeau, Christopher P.; Borgmann, Kathi L.

    2017-01-01

    Understanding species–habitat relationships for endangered species is critical for their conservation. However, many studies have limited value for conservation because they fail to account for habitat associations at multiple spatial scales, anthropogenic variables, and imperfect detection. We addressed these three limitations by developing models for an endangered wetland bird, Yuma Ridgway's rail (Rallus obsoletus yumanensis), that examined how the spatial scale of environmental variables, inclusion of anthropogenic disturbance variables, and accounting for imperfect detection in validation data influenced model performance. These models identified associations between environmental variables and occupancy. We used bird survey and spatial environmental data at 2473 locations throughout the species' U.S. range to create and validate occupancy models and produce predictive maps of occupancy. We compared habitat-based models at three spatial scales (100, 224, and 500 m radii buffers) with and without anthropogenic disturbance variables using validation data adjusted for imperfect detection and an unadjusted validation dataset that ignored imperfect detection. The inclusion of anthropogenic disturbance variables improved the performance of habitat models at all three spatial scales, and the 224-m-scale model performed best. All models exhibited greater predictive ability when imperfect detection was incorporated into validation data. Yuma Ridgway's rail occupancy was negatively associated with ephemeral and slow-moving riverine features and high-intensity anthropogenic development, and positively associated with emergent vegetation, agriculture, and low-intensity development. Our modeling approach accounts for common limitations in modeling species–habitat relationships and creating predictive maps of occupancy probability and, therefore, provides a useful framework for other species.

  3. Effects of habitat structure on the epifaunal community in Mussismilia corals: does coral morphology influence the richness and abundance of associated crustacean fauna?

    NASA Astrophysics Data System (ADS)

    Nogueira, Marcos M.; Neves, Elizabeth; Johnsson, Rodrigo

    2015-06-01

    Coral habitat structures increase abundance and richness of organisms by providing niches, easy access to resources and refuge from predators. Corals harbor a great variety of animals; the variation in coral species morphology contributes to the heterogeneity and complexity of habitat types. In this report, we studied the richness and abundance of crustaceans (Decapoda, Copepoda, Peracarida and Ostracoda) associated with three species of Mussismilia exhibiting different growth morphologies, in two different coral reefs of the Bahia state (Caramuanas and Boipeba-Moreré, Brazil). Mussismilia hispida is a massive coral; M. braziliensis also has a massive growth pattern, but forms a crevice in the basal area of the corallum; M. harttii has a meandroid pattern. PERMANOVA analysis suggests significant differences in associated fauna richness among Mussismilia species, with higher values for M. harttii, followed by M. braziliensis and later by M. hispida. The same trend was observed for density, except that the comparison of M. braziliensis and M. hispida did not show differences. Redundancy and canonical correspondence analysis indicated that almost all of the crustacean species were more associated with the M. harttii colonies that formed a group clearly separated from colonies of M. braziliensis and M. hispida. We also found that the internal volume of interpolyp space, only present in M. harttii, was the most important factor influencing richness and abundance of all analyzed orders of crustaceans.

  4. North American Brant: Effects of changes in habitat and climate on population dynamics

    USGS Publications Warehouse

    Ward, David H.; Reed, Austin; Sedinger, James S.; Black, Jeffrey M.; Derksen, Dirk V.; Castelli, Paul M.

    2005-01-01

    We describe the importance of key habitats used by four nesting populations of nearctic brant (Branta bernicla) and discuss the potential relationship between changes in these habitats and population dynamics of brant. Nearctic brant, in contrast to most geese, rely on marine habitats and native intertidal plants during the non-breeding season, particularly the seagrass, Zostera, and the macroalgae, Ulva. Atlantic and Eastern High Arctic brant have experienced the greatest degradation of their winter habitats (northeastern United States and Ireland, respectively) and have also shown the most plasticity in feeding behavior. Black and Western High Arctic brant of the Pacific Flyway are the most dependent on Zostera, and are undergoing a shift in winter distribution that is likely related to climate change and its associated effects on Zostera dynamics. Variation in breeding propensity of Black Brant associated with winter location and climate strongly suggests that food abundance on the wintering grounds directly affects reproductive performance in these geese. In summer, salt marshes, especially those containing Carex and Puccinellia, are key habitats for raising young, while lake shorelines with fine freshwater grasses and sedges are important for molting birds. Availability and abundance of salt marshes has a direct effect on growth and recruitment of goslings and ultimately, plays an important role in regulating size of local brant populations. ?? 2005 Blackwell Publishing Ltd.

  5. Drought survival is a threshold function of habitat size and population density in a fish metapopulation.

    PubMed

    White, Richard S A; McHugh, Peter A; McIntosh, Angus R

    2016-10-01

    Because smaller habitats dry more frequently and severely during droughts, habitat size is likely a key driver of survival in populations during climate change and associated increased extreme drought frequency. Here, we show that survival in populations during droughts is a threshold function of habitat size driven by an interaction with population density in metapopulations of the forest pool dwelling fish, Neochanna apoda. A mark-recapture study involving 830 N. apoda individuals during a one-in-seventy-year extreme drought revealed that survival during droughts was high for populations occupying pools deeper than 139 mm, but declined steeply in shallower pools. This threshold was caused by an interaction between increasing population density and drought magnitude associated with decreasing habitat size, which acted synergistically to increase physiological stress and mortality. This confirmed two long-held hypotheses, firstly concerning the interactive role of population density and physiological stress, herein driven by habitat size, and secondly, the occurrence of drought survival thresholds. Our results demonstrate how survival in populations during droughts will depend strongly on habitat size and highlight that minimum habitat size thresholds will likely be required to maximize survival as the frequency and intensity of droughts are projected to increase as a result of global climate change. © 2016 John Wiley & Sons Ltd.

  6. Landscape composition and habitat area affects butterfly species richness in semi-natural grasslands.

    PubMed

    Ockinger, Erik; Smith, Henrik G

    2006-09-01

    During the last 50 years, the distribution and abundance of many European butterfly species associated with semi-natural grasslands have declined. This may be the result of deteriorating habitat quality, but habitat loss, resulting in decreasing area and increasing isolation of remaining habitat, is also predicted to result in reduced species richness. To investigate the effects of habitat loss on species richness, we surveyed butterflies in semi-natural grasslands of similar quality and structure, but situated in landscapes of different habitat composition. Using spatially explicit habitat data, we selected one large (6-10 ha) and one small (0.5-2 ha) grassland site (pasture) in each of 24 non-overlapping 28.2 km(2) landscapes belonging to three categories differing in the proportion of the area that consisted of semi-natural grasslands. After controlling for local habitat quality, species richness was higher in grassland sites situated in landscapes consisting of a high proportion of grasslands. Species richness was also higher in larger grassland sites, and this effect was more pronounced for sedentary than for mobile species. However, the number of species for a given area did not differ between large and small grasslands. There was also a significant relationship between butterfly species richness and habitat quality in the form of vegetation height and abundance of flowers. In contrast, butterfly density was not related to landscape composition or grassland size. When species respond differently to habitat area or landscape composition this leads to effects on community structure, and nestedness analysis showed that depauperate communities were subsets of richer ones. Both grassland area and landscape composition may have contributed to this pattern, implying that small habitat fragments and landscapes with low proportions of habitat are both likely to mainly contain common generalist species. Based on these results, conservation efforts should aim at

  7. Temporal and Spatial Scales Matter: Circannual Habitat Selection by Bird Communities in Vineyards

    PubMed Central

    Arlettaz, Raphaël; Korner, Pius

    2017-01-01

    Vineyards are likely to be regionally important for wildlife, but we lack biodiversity studies in this agroecosystem which is undergoing a rapid management revolution. As vine cultivation is restricted to arid and warm climatic regions, biodiversity-friendly management would promote species typical of southern biomes. Vineyards are often intensively cultivated, mostly surrounded by few natural features and offering a fairly mineral appearance with little ground vegetation cover. Ground vegetation cover and composition may further strongly vary with respect to season, influencing patterns of habitat selection by ecological communities. We investigated season-specific bird-habitat associations to highlight the importance of semi-natural habitat features and vineyard ground vegetation cover throughout the year. Given that avian habitat selection varies according to taxa, guilds and spatial scale, we modelled bird-habitat associations in all months at two spatial scales using mixed effects regression models. At the landscape scale, birds were recorded along 10 1-km long transects in Southwestern Switzerland (February 2014 –January 2015). At the field scale, we compared the characteristics of visited and unvisited vineyard fields (hereafter called parcels). Bird abundance in vineyards tripled in winter compared to summer. Vineyards surrounded by a greater amount of hedges and small woods harboured higher bird abundance, species richness and diversity, especially during the winter season. Regarding ground vegetation, birds showed a season-specific habitat selection pattern, notably a marked preference for ground-vegetated parcels in winter and for intermediate vegetation cover in spring and summer. These season-specific preferences might be related to species-specific life histories: more insectivorous, ground-foraging species occur during the breeding season whereas granivores predominate in winter. These results highlight the importance of investigating habitat

  8. Bacterial community variation in human body habitats across space and time.

    PubMed

    Costello, Elizabeth K; Lauber, Christian L; Hamady, Micah; Fierer, Noah; Gordon, Jeffrey I; Knight, Rob

    2009-12-18

    Elucidating the biogeography of bacterial communities on the human body is critical for establishing healthy baselines from which to detect differences associated with diseases. To obtain an integrated view of the spatial and temporal distribution of the human microbiota, we surveyed bacteria from up to 27 sites in seven to nine healthy adults on four occasions. We found that community composition was determined primarily by body habitat. Within habitats, interpersonal variability was high, whereas individuals exhibited minimal temporal variability. Several skin locations harbored more diverse communities than the gut and mouth, and skin locations differed in their community assembly patterns. These results indicate that our microbiota, although personalized, varies systematically across body habitats and time; such trends may ultimately reveal how microbiome changes cause or prevent disease.

  9. Habitat assortment of sexes and water balance in a dioecious grass.

    PubMed

    Fox, J F; Harrison, A Tyrone

    1981-05-01

    For a dioecious plant species in which males are associated with more xeric habitats and females with more mesic ones, (a) the xeric-mesic habitat difference was confirmed by measuring plant water potential, (b) and males and females had similar water balances and seemed to have no different adaptations to drought. There are slight differences in water potential between the sexes of dioecious plant species, but water balance can be more favorable in either the male or the female. On this account, we reject the "disruptive selection" hypothesis of Freeman et al. (1975) as an explanation for habitat assortment of sexes in dioecious plants. Alternative explanations, based upon parental determination of offspring sex ratios, or environmentally determined sex change, seem more likely.

  10. Selecting compact habitat reserves for species with differential habitat size needs

    Treesearch

    Vladimir Marianov; Charles ReVelle; Stephanie Snyder

    2008-01-01

    We propose a model for the design of protected habitat reserves, which maximizes the number of species represented at least once in a limited set of reserved sites or parcels. Most models for reserve design do not differentiate eligible habitat sites by their size. Also, they assume that protection is guaranteed through the selection of one site for any species, not...

  11. Reducing the data-deficiency of threatened European habitats: Spatial variation of sabellariid worm reefs and associated fauna in the Sicily Channel, Mediterranean Sea.

    PubMed

    Bertocci, Iacopo; Badalamenti, Fabio; Lo Brutto, Sabrina; Mikac, Barbara; Pipitone, Carlo; Schimmenti, Eugenia; Vega Fernández, Tomás; Musco, Luigi

    2017-09-01

    Biogenic reefs, such as those produced by tube-dwelling polychaetes of the genus Sabellaria, are valuable marine habitats which are a focus of protection according to European legislation. The achievement of this goal is potentially hindered by the lack of essential empirical data, especially in the Mediterranean Sea. This study addresses some of the current knowledge gaps by quantifying and comparing multi-scale patterns of abundance and distribution of two habitat-forming species (Sabellaria alveolata and S. spinulosa) and their associated fauna along 190 km of coast on the Italian side of the Sicily Channel. While the abundance of the two sabellariids and the total number of associated taxa did not differ at any of the examined scales (from tens of centimetres to tens-100 of kilometres), the structure (composition in terms of both the identity and the relative abundance of constituting taxa) of the associated fauna and the abundance of several taxa (the polychaetes Eulalia ornata, Syllis pulvinata, S. garciai, Nereis splendida and Arabella iricolor, and the amphipods Apolochus neapolitanus, Tethylembos viguieri and Caprella acanthifera) varied among locations established ∼50-100 km apart. Syllis pulvinata also showed significant variation between sites (hundreds of metres apart), analogously to the other syllid polychaetes S. armillaris and S. gracilis, the nereidid polychaete Nereis rava, and the amphipod Gammaropsis ulrici. The largest variance of S. spinulosa, of the structure of the whole associated fauna and of 56% of taxa analysed individually occurred at the scale of replicates (metres apart), while that of the dominant bio-constructor S. alveolata and of 25% of taxa occurred at the scale of sites. The remaining 19% and the total richness of taxa showed the largest variance at the scale of locations. Present findings contribute to meet a crucial requirement of any future effective protection strategy, i.e., identifying relevant scales of

  12. Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA

    PubMed Central

    Arkle, Robert S; Pilliod, David S

    2015-01-01

    A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species’ range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

  13. Tumor image signatures and habitats: a processing pipeline of multimodality metabolic and physiological images.

    PubMed

    You, Daekeun; Kim, Michelle M; Aryal, Madhava P; Parmar, Hemant; Piert, Morand; Lawrence, Theodore S; Cao, Yue

    2018-01-01

    To create tumor "habitats" from the "signatures" discovered from multimodality metabolic and physiological images, we developed a framework of a processing pipeline. The processing pipeline consists of six major steps: (1) creating superpixels as a spatial unit in a tumor volume; (2) forming a data matrix [Formula: see text] containing all multimodality image parameters at superpixels; (3) forming and clustering a covariance or correlation matrix [Formula: see text] of the image parameters to discover major image "signatures;" (4) clustering the superpixels and organizing the parameter order of the [Formula: see text] matrix according to the one found in step 3; (5) creating "habitats" in the image space from the superpixels associated with the "signatures;" and (6) pooling and clustering a matrix consisting of correlation coefficients of each pair of image parameters from all patients to discover subgroup patterns of the tumors. The pipeline was applied to a dataset of multimodality images in glioblastoma (GBM) first, which consisted of 10 image parameters. Three major image "signatures" were identified. The three major "habitats" plus their overlaps were created. To test generalizability of the processing pipeline, a second image dataset from GBM, acquired on the scanners different from the first one, was processed. Also, to demonstrate the clinical association of image-defined "signatures" and "habitats," the patterns of recurrence of the patients were analyzed together with image parameters acquired prechemoradiation therapy. An association of the recurrence patterns with image-defined "signatures" and "habitats" was revealed. These image-defined "signatures" and "habitats" can be used to guide stereotactic tissue biopsy for genetic and mutation status analysis and to analyze for prediction of treatment outcomes, e.g., patterns of failure.

  14. Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA.

    PubMed

    Arkle, Robert S; Pilliod, David S

    2015-09-01

    A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species' range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

  15. Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA

    USGS Publications Warehouse

    Arkle, Robert S.; Pilliod, David S.

    2015-01-01

    A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species’ range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

  16. Invasion by non-native brook trout in Panther Creek, Idaho: Roles of habitat quality, biotic resistance, and connectivity to source habitats

    Treesearch

    Joseph R. Benjamin; Jason B. Dunham; Matthew R. Dare

    2007-01-01

    Theoretical models and empirical evidence suggest that the invasion of nonnative species in freshwaters is facilitated through the interaction of three factors: habitat quality, biotic resistance, and connectivity. We measured variables that represented each factor to determine which were associated with the occurrence of nonnative brook trout Salvelinus...

  17. Estimating habitat value using forest inventory data: the fisher (Martes pennanti) in northwestern California

    Treesearch

    William J. Zielinski; Jeffrey R. Dunk; Andrew N. Gray

    2012-01-01

    Managing forests for multiple objectives requires balancing timber and vegetation management objectives with needs of sensitive species. Especially challenging is how to retain the habitat elements for species that are typically associated with late-seral forests. We develop a regionally specific, multivariate model describing habitat selection that can be used – when...

  18. CADDIS Volume 2. Sources, Stressors and Responses: Urbanization - Physical Habitat

    EPA Pesticide Factsheets

    Introduction to physical habitat changes associated with urbanization, overview of how urbanization can lead to channel enlargement, summary of how road crossings can affect stream ecosystems, summary of how urbanization can alter streambed substrates.

  19. Effects of Grazing Management and Cattle on Aquatic Habitat Use by the Anuran Pseudopaludicola mystacalis in Agro-Savannah Landscapes

    PubMed Central

    Garey, Michel V.; Rossa-Feres, Denise C.

    2016-01-01

    Because of their strong dependence on the environment, the spatial distribution of pond-breeding amphibians can be greatly influenced by anthropogenic habitat alteration. In some agricultural landscapes in Brazil, the anuran Pseudopaludicola mystacalis appears to be highly influenced by land use. Because adult males and tadpoles of this species are usually found in marshy areas with cattle hoof prints, we hypothesized that P. mystacalis preferentially occupies aquatic habitats with marshy areas that are trampled by cattle. To test our hypothesis, we assessed whether the occurrence of P. mystacalis is associated with the presence of cattle and trampled marshy areas, and which environmental features best explain the spatial distribution and abundance of P. mystacalis. To do so, we sampled 38 aquatic habitats in an area intensely used for livestock in southeastern Brazil. We found that the presence of cattle and trampled marshy areas in aquatic habitats are positively associated to P. mystacalis occurrence. Additionally, the abundance of calling males is better predicted by variables of landscape and local habitat structure. Specifically, the size of trampled marshy areas and the proportion of herbaceous vegetation within the aquatic habitat are positively associated with abundance, while distance to nearest aquatic habitat are negatively associated with abundance of calling males. All three of these variables can be directly or indirectly linked to the presence of cattle or grazing management. Therefore, this work shows evidence that Pseudopaludicola mystacalis is positively influenced by grazing management with cattle, and draws attention to other unknown potential consequences of different land use to fresh water diversity. PMID:27658203

  20. Littorally adaptive? Testing the link between habitat, morphology, and reproduction in the intertidal sculpin subfamily Oligocottinae (Pisces: Cottoidea)

    PubMed Central

    Burns, Michael D.; López, J. Andrés

    2017-01-01

    While intertidal habitats are often productive, species-rich environments, they are also harsh and highly dynamic. Organisms that live in these habitats must possess morphological and physiological adaptations that enable them to do so. Intertidal fishes are generally small, often lack scales, and the diverse families represented in intertidal habitats often show convergence into a few general body shapes. However, few studies have quantified the relationship between phenotypes and intertidal living. Likewise, the diversity of reproductive traits and parental care in intertidal fishes has yet to be compared quantitatively with habitat. We examine the relationship of these characters in the sculpin subfamily Oligocottinae using a phylogenetic hypothesis, geometric morphometrics, and phylogenetic comparative methods to provide the first formal test of associations between fish phenotypes and reproductive characters with intertidal habitats. We show that the ability to live in intertidal habitats, particularly in tide pools, is likely a primitive state for Oligocottinae, with a single species that has secondarily come to occupy only subtidal habitats. Contrary to previous hypotheses, maximum size and presence of scales do not show a statistically significant correlation with depth. However, the maximum size for all species is generally small (250 mm or less) and all show a reduction in scales, as would be expected for an intertidal group. Also contrary to previous hypotheses, we show that copulation and associated characters are the ancestral condition in Oligocottinae, with copulation most likely being lost in a single lineage within the genus Artedius. Lastly, we show that body shape appears to be constrained among species with broader depth ranges, but lineages that occupy only a narrow range of intertidal habitats display novel body shapes, and this may be associated with habitat partitioning, particularly as it relates to the degree of wave exposure. PMID

  1. Littorally adaptive? Testing the link between habitat, morphology, and reproduction in the intertidal sculpin subfamily Oligocottinae (Pisces: Cottoidea).

    PubMed

    Buser, Thaddaeus J; Burns, Michael D; López, J Andrés

    2017-01-01

    While intertidal habitats are often productive, species-rich environments, they are also harsh and highly dynamic. Organisms that live in these habitats must possess morphological and physiological adaptations that enable them to do so. Intertidal fishes are generally small, often lack scales, and the diverse families represented in intertidal habitats often show convergence into a few general body shapes. However, few studies have quantified the relationship between phenotypes and intertidal living. Likewise, the diversity of reproductive traits and parental care in intertidal fishes has yet to be compared quantitatively with habitat. We examine the relationship of these characters in the sculpin subfamily Oligocottinae using a phylogenetic hypothesis, geometric morphometrics, and phylogenetic comparative methods to provide the first formal test of associations between fish phenotypes and reproductive characters with intertidal habitats. We show that the ability to live in intertidal habitats, particularly in tide pools, is likely a primitive state for Oligocottinae, with a single species that has secondarily come to occupy only subtidal habitats. Contrary to previous hypotheses, maximum size and presence of scales do not show a statistically significant correlation with depth. However, the maximum size for all species is generally small (250 mm or less) and all show a reduction in scales, as would be expected for an intertidal group. Also contrary to previous hypotheses, we show that copulation and associated characters are the ancestral condition in Oligocottinae, with copulation most likely being lost in a single lineage within the genus Artedius . Lastly, we show that body shape appears to be constrained among species with broader depth ranges, but lineages that occupy only a narrow range of intertidal habitats display novel body shapes, and this may be associated with habitat partitioning, particularly as it relates to the degree of wave exposure.

  2. Species’ traits help predict small mammal responses to habitat homogenization by an invasive grass

    USGS Publications Warehouse

    Ceradini, Joseph P.; Chalfoun, Anna D.

    2017-01-01

    Invasive plants can negatively affect native species, however, the strength, direction, and shape of responses may vary depending on the type of habitat alteration and the natural history of native species. To prioritize conservation of vulnerable species, it is therefore critical to effectively predict species’ responses to invasive plants, which may be facilitated by a framework based on species’ traits. We studied the population and community responses of small mammals and changes in habitat heterogeneity across a gradient of cheatgrass (Bromus tectorum) cover, a widespread invasive plant in North America. We live-trapped small mammals over two summers and assessed the effect of cheatgrass on native small mammal abundance, richness, and species-specific and trait-based occupancy, while accounting for detection probability and other key habitat elements. Abundance was only estimated for the most common species, deer mice (Peromyscus maniculatus). All species were pooled for the trait-based occupancy analysis to quantify the ability of small mammal traits (habitat association, mode of locomotion, and diet) to predict responses to cheatgrass invasion. Habitat heterogeneity decreased with cheatgrass cover. Deer mouse abundance increased marginally with cheatgrass. Species richness did not vary with cheatgrass, however, pocket mouse (Perognathus spp.) and harvest mouse (Reithrodontomys spp.) occupancy tended to decrease and increase, respectively, with cheatgrass cover, suggesting a shift in community composition. Cheatgrass had little effect on occupancy for deer mice, 13-lined ground squirrels (Spermophilus tridecemlineatus), and Ord's kangaroo rat (Dipodomys ordii). Species’ responses to cheatgrass primarily corresponded with our a priori predictions based on species’ traits. The probability of occupancy varied significantly with a species’ habitat association but not with diet or mode of locomotion. When considered within the context of a rapid

  3. Distribution, abundance, and habitat associations of a large bivalve (Panopea generosa) in a eutrophic, fjord estuary

    USGS Publications Warehouse

    Mcdonald, P. Sean; Essington, Timothy E.; Davis, Jonathan P.; Galloway, Aaron W.E.; Stevick, Bethany C.; Jensen, Gregory C.; VanBlaricom, Glenn R.; Armstrong, David A.

    2015-01-01

    Marine bivalves are important ecosystem constituents and frequently support valuable fisheries. In many nearshore areas, human disturbance—including declining habitat and water quality—can affect the distribution and abundance of bivalve populations, and complicate ecosystem and fishery management assessments. Infaunal bivalves, in particular, are frequently cryptic and difficult to detect; thus, assessing potential impacts on their populations requires suitable, scalable methods for estimating abundance and distribution. In this study, population size of a common benthic bivalve (the geoduck Panopea generosa) is estimated with a Bayesian habitat-based model fit to scuba and tethered camera data in Hood Canal, a fjord basin in Washington state. Densities declined more than two orders of magnitude along a north—south gradient, concomitant with patterns of deepwater dissolved oxygen, and intensity and duration of seasonal hypoxia. Across the basin, geoducks were most abundant in loose, unconsolidated, sand substrate. The current study demonstrates the utility of using scuba, tethered video, and habitat models to estimate the abundance and distribution of a large infaunal bivalve at a regional (385-km2) scale.

  4. Habitat Suitability Index Models: Black-shouldered kite

    USGS Publications Warehouse

    Faanes, Craig A.; Howard, Rebecca J.

    1987-01-01

    A review and synthesis of existing information were used to develop a model for evaluating black-shouldered kite habitat quality. The model is scaled to produce an index between 0 (unsuitable habitat) to 1.0 (optimal habitat). Habitat suitability index models are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for model application are provided.

  5. Anthropogenic areas as incidental substitutes for original habitat.

    PubMed

    Martínez-Abraín, Alejandro; Jiménez, Juan

    2016-06-01

    One speaks of ecological substitutes when an introduced species performs, to some extent, the ecosystem function of an extirpated native species. We suggest that a similar case exists for habitats. Species evolve within ecosystems, but habitats can be destroyed or modified by natural and human-made causes. Sometimes habitat alteration forces animals to move to or remain in a suboptimal habitat type. In that case, the habitat is considered a refuge, and the species is called a refugee. Typically refugee species have lower population growth rates than in their original habitats. Human action may lead to the unintended generation of artificial or semiartificial habitat types that functionally resemble the essential features of the original habitat and thus allow a population growth rate of the same magnitude or higher than in the original habitat. We call such areas substitution habitats and define them as human-made habitats within the focal species range that by chance are partial substitutes for the species' original habitat. We call species occupying a substitution habitat adopted species. These are 2 new terms in conservation biology. Examples of substitution habitats are dams for European otters, wheat and rice fields for many steppeland and aquatic birds, and urban areas for storks, falcons, and swifts. Although substitution habitats can bring about increased resilience against the agents of global change, the conservation of original habitat types remains a conservation priority. © 2016 Society for Conservation Biology.

  6. Habitat Design Optimization and Analysis

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Hull, Patrick V.; Tinker, Michael L.

    2006-01-01

    Long-duration surface missions to the Moon and Mars will require habitats for the astronauts. The materials chosen for the habitat walls play a direct role in the protection against the harsh environments found on the surface. Choosing the best materials, their configuration, and the amount required is extremely difficult due to the immense size of the design region. Advanced optimization techniques are necessary for habitat wall design. Standard optimization techniques are not suitable for problems with such large search spaces; therefore, a habitat design optimization tool utilizing genetic algorithms has been developed. Genetic algorithms use a "survival of the fittest" philosophy, where the most fit individuals are more likely to survive and reproduce. This habitat design optimization tool is a multi-objective formulation of structural analysis, heat loss, radiation protection, and meteoroid protection. This paper presents the research and development of this tool.

  7. Vertical pelagic habitat of euphausiid species assemblages in the Gulf of California

    NASA Astrophysics Data System (ADS)

    Ambriz-Arreola, Israel; Gómez-Gutiérrez, Jaime; Franco-Gordo, María del Carmen; Palomares-García, Ricardo J.; Sánchez-Velasco, Laura; Robinson, Carlos J.; Seibel, Brad A.

    2017-05-01

    We describe the seasonal changes in the horizontal and vertical distribution and abundance of euphausiid species associated with seven physical and 61 biological variables in the Gulf of California (24-31°N). Euphausiid community structure was explored in the epipelagic habitat (<200 m) in January, July, and October 2007 and in epipelagic to bathypelagic habitats (<1400 m depth) in May 2015. Twelve euphausiid species comprising two distinct regional assemblages were identified. Nyctiphanes simplex and Nematoscelis difficilis were the most abundant species (>90%) in all cruises carried out in the 26-31°N region and Euphausia distinguenda in the 24-26°N region (mostly in October >90%). We confirmed that Euphausia gibboides and Nematobrachion flexipes inhabit the mesopelagic habitat, adapted to <1 ml O2 l-1 environmental condition. Although Euphausia lamelligera and N. simplex populations were concentrated in well-oxygenated water (>3 ml O2 l-1) near the surface (<50 m), they were also detected in low densities in the hypoxic mesopelagic habitat (250-800 m), but only at oxygen levels less than 0.09 ml O2 l-1. Stylocheiron affine and Stylocheiron carinatum were numerous well below the seasonal thermocline (100-350 m). Nematoscelis difficilis and N. simplex extended into the hypoxic mesopelagic habitat, but at low densities. Multivariate analyses showed six seasonal and regional krill assemblages, which are characterized by different species (Similarity percentage analysis). Canonical Correspondence Analysis show that, of 68 variables, three abiotic factors (temperature, dissolved oxygen, and OMZ depth) and eight biotic factors (accessory pigments; zeaxanthin and 19'-hexanoyloxyfucoxanthin, and the abundance of six copepod species; Candacia pectinata, Canthocalanus pauper, Centropages furcatus, Rhincalanus nasutus, Scolecithrix danae, and Temora discaudata), were the most influential variables associated with the vertical distribution and abundance of euphausiids

  8. Seasonal variation in habitat use of juvenile Steelhead in a tributary of Lake Ontario

    USGS Publications Warehouse

    Studdert, Emily W.; Johnson, James H.

    2015-01-01

    We examined seasonal-habitat use by subyearling and yearling Oncorhynchus mykiss (Rainbow Trout or Steelhead) in Trout Brook, a tributary of the Salmon River, NY. We determined daytime fish-habitat use and available habitat during August and October of the same year and observed differences in habitat selection among year classes. Water depth and cover played the greatest role in Steelhead habitat use. During summer and autumn, we found yearling Steelhead in areas with deeper water and more cover than where we observed subyearling Steelhead. Both year classes sought out areas with abundant cover during both seasons; this habitat was limited within the stream reach. Subyearling Steelhead were associated with more cover during autumn, even though available cover within the stream reach was greater during summer. Principal component analysis showed that variation in seasonal-habitat use was most pronounced for subyearling Steelhead and that yearling Steelhead were more selective in their habitat use than subyearling Steelhead. The results of this study contribute to a greater understanding of how this popular sportfish is adapting to a new environment and the factors that may limit juvenile Steelhead survival. Our findings provide valuable new insights into the seasonal-habitat requirements of subyearling and yearling Steelhead that can be used by fisheries managers to enhance and protect the species throughout the Great Lakes region.

  9. Frugivorous bats maintain functional habitat connectivity in agricultural landscapes but rely strongly on natural forest fragments.

    PubMed

    Ripperger, Simon P; Kalko, Elisabeth K V; Rodríguez-Herrera, Bernal; Mayer, Frieder; Tschapka, Marco

    2015-01-01

    Anthropogenic changes in land use threaten biodiversity and ecosystem functioning by the conversion of natural habitat into agricultural mosaic landscapes, often with drastic consequences for the associated fauna. The first step in the development of efficient conservation plans is to understand movement of animals through complex habitat mosaics. Therefore, we studied ranging behavior and habitat use in Dermanura watsoni (Phyllostomidae), a frugivorous bat species that is a valuable seed disperser in degraded ecosystems. Radio-tracking of sixteen bats showed that the animals strongly rely on natural forest. Day roosts were exclusively located within mature forest fragments. Selection ratios showed that the bats foraged selectively within the available habitat and positively selected natural forest. However, larger daily ranges were associated with higher use of degraded habitats. Home range geometry and composition of focal foraging areas indicated that wider ranging bats performed directional foraging bouts from natural to degraded forest sites traversing the matrix over distances of up to three hundred meters. This behavior demonstrates the potential of frugivorous bats to functionally connect fragmented areas by providing ecosystem services between natural and degraded sites, and highlights the need for conservation of natural habitat patches within agricultural landscapes that meet the roosting requirements of bats.

  10. Range and Primary Habitats of Hawaiian Insular False Killer Whales: Informing Determination of Critical Habitat

    DTIC Science & Technology

    2012-07-20

    whales Eubalaena glacialis (in 1994), ‘ southern resident ’ killer whales (in 2006), North Pacific right whales E...reviewed evaluation of specific and essential habitat features. For example, for southern resident killer whales , a population that uses both US and...critical habitat for southern resident killer whale . Federal Register 71: 69054−69070 Federal Register (2008) Designation of critical habitat for

  11. Habitat and distribution of post-recruit life stages of the squid Loligo forbesii

    NASA Astrophysics Data System (ADS)

    Smith, Jennifer M.; Macleod, Colin D.; Valavanis, Vasilis; Hastie, Lee; Valinassab, Tooraj; Bailey, Nick; Santos, M. Begoña; Pierce, Graham J.

    2013-10-01

    This study models habitat preferences of the squid Loligo forbesii through its post-recruitment life cycle in waters around Scotland (UK). Trawl survey and market sample data from 1985 to 2004 are used to model seasonal habitats of immature, maturing and mature squid (maturity being inferred from size and season). Squid presence-absence and catch rate in areas of presence were analysed using generalised additive models, relating spatiotemporal patterns of distribution and abundance to ecogeographic variables. For all maturity classes, higher abundance in winter and spring (i.e., quarters 1 and 2) was associated with deeper water while higher abundance in summer and autumn (quarters 3 and 4) was associated with shallower water, consistent with seasonal onshore-offshore migrations but suggesting that most spawning may take place in deeper waters. The preferred SST range was generally 8-8.75 °C while preferred salinity values were below 35‰ in winter and summer and above 35‰ in spring and autumn. Squid were positively associated with gravel substrate and negatively associated with mud. Seasonal changes in habitat use were more clearly evident than changes related to inferred maturity, although the two effects cannot be fully separated due to the annual life cycle. Habitat selection for this species can be satisfactorily modelled on a seasonal basis; predictions based on such models could be useful for fishers to target the species more effectively, and could assist managers wishing to protect spawning grounds. The extent to which this approach may be useful for other cephalopods is discussed.

  12. Avian communities in tidal salt marshes of San Francisco Bay: a review of functional groups by foraging guild and habitat association

    USGS Publications Warehouse

    Takekawa, John Y.; Woo, Isa; Gardiner, Rachel J.; Casazza, Michael L.; Ackerman, Joshua T.; Nur, Nadav; Liu, Leonard; Spautz, Hildie; Palaima, Arnas

    2011-01-01

    The San Francisco Bay estuary is highly urbanized, but it supports the largest remaining extent of tidal salt marshes on the west coast of North America as well as a diverse native bird community. San Francisco Bay tidal marshes are occupied by more than 113 bird species that represent 31 families, including five subspecies from three families that we denote as tidal-marsh obligates. To better identify the niche of bird species in tidal marshes, we present a review of functional groups based on foraging guilds and habitat associations. Foraging guilds describe the method by which species obtain food from tidal marshes, while habitat associations describe broad areas within the marsh that have similar environmental conditions. For example, the ubiquitous song sparrows (Alameda Melospiza melodia pusillula, Suisun M. m. maxillaris, and San Pablo M. m. samuelis) are surface-feeding generalists that consume prey from vegetation and the ground, and they are found across the entire marsh plain into the upland–marsh transition. In contrast, surface-feeding California black rails (Laterallus jamaicensis coturniculus) are cryptic, and generally restricted in their distribution to the mid- and high-marsh plain. Although in the same family, the endangered California clapper rail (Rallus longirostris obsoletus) has become highly specialized, foraging primarily on benthic fauna within marsh channels when they are exposed at low tide. Shorebirds such as the black-necked stilt (Himantopus mexicanus) typically probe in mud flats to consume macroinvertebrate prey, and are generally restricted to foraging on salt pans within the marsh plain, in ponds, or on mud flats during transitional stages of marsh evolution. The abundance and distribution of birds varies widely with changing water depths and vegetation colonization during different stages of restoration. Thus, tidal-marsh birds represent a rich and diverse community in bay marshes, with niches that may be distinguished by the

  13. The importance of accounting for larval detectability in mosquito habitat-association studies.

    PubMed

    Low, Matthew; Tsegaye, Admasu Tassew; Ignell, Rickard; Hill, Sharon; Elleby, Rasmus; Feltelius, Vilhelm; Hopkins, Richard

    2016-05-04

    Mosquito habitat-association studies are an important basis for disease control programmes and/or vector distribution models. However, studies do not explicitly account for incomplete detection during larval presence and abundance surveys, with potential for significant biases because of environmental influences on larval behaviour and sampling efficiency. Data were used from a dip-sampling study for Anopheles larvae in Ethiopia to evaluate the effect of six factors previously associated with larval sampling (riparian vegetation, direct sunshine, algae, water depth, pH and temperature) on larval presence and detectability. Comparisons were made between: (i) a presence-absence logistic regression where samples were pooled at the site level and detectability ignored, (ii) a success versus trials binomial model, and (iii) a presence-detection mixture model that separately estimated presence and detection, and fitted different explanatory variables to these estimations. Riparian vegetation was consistently highlighted as important, strongly suggesting it explains larval presence (-). However, depending on how larval detectability was estimated, the other factors showed large variations in their statistical importance. The presence-detection mixture model provided strong evidence that larval detectability was influenced by sunshine and water temperature (+), with weaker evidence for algae (+) and water depth (-). For larval presence, there was also some evidence that water depth (-) and pH (+) influenced site occupation. The number of dip-samples needed to determine if larvae were likely present at a site was condition dependent: with sunshine and warm water requiring only two dips, while cooler water and cloud cover required 11. Environmental factors influence true larval presence and larval detectability differentially when sampling in field conditions. Researchers need to be more aware of the limitations and possible biases in different analytical approaches used to

  14. Railway Embankments as New Habitat for Pollinators in an Agricultural Landscape

    PubMed Central

    Moroń, Dawid; Skórka, Piotr; Lenda, Magdalena; Rożej-Pabijan, Elżbieta; Wantuch, Marta; Kajzer-Bonk, Joanna; Celary, Waldemar; Mielczarek, Łukasz Emil; Tryjanowski, Piotr

    2014-01-01

    Pollinating insect populations, essential for maintaining wild plant diversity and agricultural productivity, rely on (semi)natural habitats. An increasing human population is encroaching upon and deteriorating pollinator habitats. Thus the population persistence of pollinating insects and their associated ecosystem services may depend upon on man-made novel habitats; however, their importance for ecosystem services is barely understood. We tested if man-made infrastructure (railway embankments) in an agricultural landscape establishes novel habitats that support large populations of pollinators (bees, butterflies, hoverflies) when compared to typical habitats for these insects, i.e., semi-natural grasslands. We also identified key environmental factors affecting the species richness and abundance of pollinators on embankments. Species richness and abundance of bees and butterflies were higher for railway embankments than for grasslands. The occurrence of bare (non-vegetated) ground on embankments positively affected bee species richness and abundance, but negatively affected butterfly populations. Species richness and abundance of butterflies positively depended on species richness of native plants on embankments, whereas bee species richness was positively affected by species richness of non-native flowering plants. The density of shrubs on embankments negatively affected the number of bee species and their abundance. Bee and hoverfly species richness were positively related to wood cover in a landscape surrounding embankments. This is the first study showing that railway embankments constitute valuable habitat for the conservation of pollinators in farmland. Specific conservation strategies involving embankments should focus on preventing habitat deterioration due to encroachment of dense shrubs and maintaining grassland vegetation with patches of bare ground. PMID:25054427

  15. Habitat stability and occurrences of malaria vector larvae in western Kenya highlands.

    PubMed

    Himeidan, Yousif E; Zhou, Guofa; Yakob, Laith; Afrane, Yaw; Munga, Stephen; Atieli, Harrysone; El-Rayah, El-Amin; Githeko, Andrew K; Yan, Guiyun

    2009-10-21

    Although the occurrence of malaria vector larvae in the valleys of western Kenya highlands is well documented, knowledge of larval habitats in the uphill sites is lacking. Given that most inhabitants of the highlands actually dwell in the uphill regions, it is important to develop understanding of mosquito breeding habitat stability in these sites in order to determine their potential for larval control. A total of 128 potential larval habitats were identified in hilltops and along the seasonal streams in the Sigalagala area of Kakamega district, western Kenya. Water availability in the habitats was followed up daily from August 3, 2006 to February 23, 2007. A habitat is defined as stable when it remains aquatic continuously for at least 12 d. Mosquito larvae were observed weekly. Frequencies of aquatic, stable and larvae positive habitats were compared between the hilltop and seasonal stream area using chi2-test. Factors affecting the presence/absence of Anopheles gambiae larvae in the highlands were determined using multiple logistic regression analysis. Topography significantly affected habitat availability and stability. The occurrence of aquatic habitats in the hilltop was more sporadic than in the stream area. The percentage of habitat occurrences that were classified as stable during the rainy season is 48.76% and 80.79% respectively for the hilltop and stream area. Corresponding frequencies of larvae positive habitats were 0% in the hilltop and 5.91% in the stream area. After the rainy season, only 23.42% of habitat occurrences were stable and 0.01% larvae positive habitats were found in the hilltops, whereas 89.75% of occurrences remained stable in the stream area resulting in a frequency of 12.21% larvae positive habitats. The logistic regression analysis confirmed the association between habitat stability and larval occurrence and indicated that habitat surface area was negatively affecting the occurrence of An. gambiae larvae. While An. gambiae and An

  16. Are vent crab behavioral preferences adaptations for habitat choice?

    PubMed

    Dahms, Hans-Uwe; Tseng, Li-Chun; Hwang, Jiang-Shiou

    2017-01-01

    Hydrothermal vent organisms are adapted to their extreme and patchily distributed habitats. They are expected to have evolved mechanisms that keep them in their specific habitation. Since little is known about the recruitment or habitat selection of HV organisms such as brachyurans, we examined the properties of several hydrothermal vent-associated cues on the behavior of the hydrothermal vent (HV) crab Xenograpsus testudinatus in the laboratory that were contrasted by the offering of non-vent cues. This crab species is endemic and dominates the vent fauna of Turtle Island off the NE coast of Taiwan. HV crabs were separately and in combination offered the following vent-specific cues: (1) sulfuric sediment, (3) air-bubbling, (4) elevated temperature, (5) dead settled zooplankton, (7) other crabs, and (8) shade. The non-vent-specific cues were: (2) quarz sediment, (6) dead fish, (8) light. These cues were provided on either side of a two-choice chamber. The movement of individual crabs was monitored: as initial and final choices, and as the proportion of time the crabs spent in each compartment (resident time). Cues were offered alone and no such cue as a control in the same set-up. Sulfuric sediments and dead fish were significantly more attractive to females, and other crabs irrespective of gender were significantly more attractive to males. When compared to expected distributions, crabs, irrespective of gender, significantly avoided light and tended to select other crabs, air-bubbling, sulfuric sediment, elevated temperature, dead fish, dead zooplankton, and quarz sediments in the order of decreasing importance. Data do not support the hypothesis that dead settled zooplankton was particularly attractive nor that the other gender was selected. A combination of several vent-associated cues (sulfuric sediment, elevated temperature, air-bubbling) facilitated the strongest attraction to the crabs as reflected by all response variables. The 'first choice' responses

  17. Seasonal habitat use of brook trout and juvenile steelhead in a Lake Ontario tributary

    USGS Publications Warehouse

    Johnson, James H.; Abbett, Ross; Chalupnicki, Marc A.; Verdoliva, Francis

    2016-01-01

    Brook trout (Salvelinus fontinalis) are generally restricted to headwaters in New York tributaries of Lake Ontario. In only a few streams are brook trout abundant in lower stream reaches that are accessible to adult Pacific salmonids migrating from the lake. Consequently, because of the rarity of native brook trout populations in these lower stream reaches it is important to understand how they use stream habitat in sympatry with juvenile Pacific salmonids which are now naturalized in several Lake Ontario tributaries. In this study, we examined the seasonal (spring, summer, and fall) habitat use of brook trout and juvenile steelhead (Oncorhynchus mykiss) in Hart Brook, a tributary of eastern Lake Ontario. We found interspecific, intraspecific, and seasonal variation in habitat use. Subyearling steelhead were associated with faster water velocities than subyearling brook trout and, overall, had the least habitat similarity to the other salmonid groups examined. Overyearling brook trout and yearling steelhead exhibited the greatest degree of habitat selection and habitat selection by all four salmonid groups was greatest in summer. The availability of pool habitat for overyearling salmonids may pose the largest impediment to these species in Hart Brook.

  18. Habitat selection and movements of Piping Plover broods suggest a tradeoff between breeding stages

    USGS Publications Warehouse

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

    2015-01-01

    In precocial birds, adults select breeding areas using cues associated with habitat characteristics that are favorable for nesting success and chick survival, but there may be tradeoffs in habitat selection between these breeding stages. Here we describe habitat selection and intra-territory movements of 53 Piping Plover (Charadrius melodus) broods (320 observations) during the 2007–2008 breeding seasons on mainland- and island-shoreline habitats at Lake Sakakawea, North Dakota, USA. We used remotely sensed habitat characteristics to separately examine habitat selection and movements at two spatiotemporal scales to account for potential confounding effects of nest-site selection on brood-rearing habitat used. The scales used were (1) the entire brood-rearing period within available brood-rearing areas and (2) 2-day observation intervals within age-specific discrete habitat selection choice sets. Analyses at both scales indicated that broods selected areas which were non-vegetated, moderately level, and nearer to the shoreline. Rate of brood movement increased with age up to 5 days, then stabilized; broods that hatched >50 m away from the shoreline moved toward the shoreline. Brood movements were greater when they were in vegetated areas, when the brood-rearing area was of greater topographic complexity, and when broods aged 6–25 days were further away from the shoreline. Using inferences from our results and those of previously published work, we postulate how a potential tradeoff in habitat selection between nesting and brood-rearing can contribute to an ecological trap in a novel habitat. This work, in the context of published works, suggests that plover breeding habitat is a complex of both nesting and brood-rearing habitats and provides a basis for making remotely sensed abundance estimates of suitable breeding habitat for Piping Plovers.

  19. A novel microbial habitat in the mid-ocean ridge subseafloor

    PubMed Central

    Summit, Melanie; Baross, John A.

    2001-01-01

    The subseafloor at the mid-ocean ridge is predicted to be an excellent microbial habitat, because there is abundant space, fluid flow, and geochemical energy in the porous, hydrothermally influenced oceanic crust. These characteristics also make it a good analog for potential subsurface extraterrestrial habitats. Subseafloor environments created by the mixing of hot hydrothermal fluids and seawater are predicted to be particularly energy-rich, and hyperthermophilic microorganisms that broadly reflect such predictions are ejected from these systems in low-temperature (≈15°C), basalt-hosted diffuse effluents. Seven hyperthermophilic heterotrophs isolated from low-temperature diffuse fluids exiting the basaltic crust in and near two hydrothermal vent fields on the Endeavour Segment, Juan de Fuca Ridge, were compared phylogenetically and physiologically to six similarly enriched hyperthermophiles from samples associated with seafloor metal sulfide structures. The 13 organisms fell into four distinct groups: one group of two organisms corresponding to the genus Pyrococcus and three groups corresponding to the genus Thermococcus. Of these three groups, one was composed solely of sulfide-derived organisms, and the other two related groups were composed of subseafloor organisms. There was no evidence of restricted exchange of organisms between sulfide and subseafloor habitats, and therefore this phylogenetic distinction indicates a selective force operating between the two habitats. Hypotheses regarding the habitat differences were generated through comparison of the physiology of the two groups of hyperthermophiles; some potential differences between these habitats include fluid flow stability, metal ion concentrations, and sources of complex organic matter. PMID:11226209

  20. Selecting habitat to survive: the impact of road density on survival in a large carnivore.

    PubMed

    Basille, Mathieu; Van Moorter, Bram; Herfindal, Ivar; Martin, Jodie; Linnell, John D C; Odden, John; Andersen, Reidar; Gaillard, Jean-Michel

    2013-01-01

    Habitat selection studies generally assume that animals select habitat and food resources at multiple scales to maximise their fitness. However, animals sometimes prefer habitats of apparently low quality, especially when considering the costs associated with spatially heterogeneous human disturbance. We used spatial variation in human disturbance, and its consequences on lynx survival, a direct fitness component, to test the Hierarchical Habitat Selection hypothesis from a population of Eurasian lynx Lynx lynx in southern Norway. Data from 46 lynx monitored with telemetry indicated that a high proportion of forest strongly reduced the risk of mortality from legal hunting at the home range scale, while increasing road density strongly increased such risk at the finer scale within the home range. We found hierarchical effects of the impact of human disturbance, with a higher road density at a large scale reinforcing its negative impact at a fine scale. Conversely, we demonstrated that lynx shifted their habitat selection to avoid areas with the highest road densities within their home ranges, thus supporting a compensatory mechanism at fine scale enabling lynx to mitigate the impact of large-scale disturbance. Human impact, positively associated with high road accessibility, was thus a stronger driver of lynx space use at a finer scale, with home range characteristics nevertheless constraining habitat selection. Our study demonstrates the truly hierarchical nature of habitat selection, which aims at maximising fitness by selecting against limiting factors at multiple spatial scales, and indicates that scale-specific heterogeneity of the environment is driving individual spatial behaviour, by means of trade-offs across spatial scales.

  1. Habitat Suitability Index Models: Red king crab

    USGS Publications Warehouse

    Jewett, Stephen C.; Onuf, Christopher P.

    1988-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for evaluating habitat of different life stages of red king crab (Paralithodes camtschatica). A model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) and 1.0 (optimum habitat) in Alaskan coastal waters, especially in the Gulf of Alaska and the southeastern Bering Sea. HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  2. Spatial, Temporal, and Density-Dependent Components of Habitat Quality for a Desert Owl

    PubMed Central

    Flesch, Aaron D.; Hutto, Richard L.; van Leeuwen, Willem J. D.; Hartfield, Kyle; Jacobs, Sky

    2015-01-01

    Spatial variation in resources is a fundamental driver of habitat quality but the realized value of resources at any point in space may depend on the effects of conspecifics and stochastic factors, such as weather, which vary through time. We evaluated the relative and combined effects of habitat resources, weather, and conspecifics on habitat quality for ferruginous pygmy-owls (Glaucidium brasilianum) in the Sonoran Desert of northwest Mexico by monitoring reproductive output and conspecific abundance over 10 years in and around 107 territory patches. Variation in reproductive output was much greater across space than time, and although habitat resources explained a much greater proportion of that variation (0.70) than weather (0.17) or conspecifics (0.13), evidence for interactions among each of these components of the environment was strong. Relative to habitat that was persistently low in quality, high-quality habitat buffered the negative effects of conspecifics and amplified the benefits of favorable weather, but did not buffer the disadvantages of harsh weather. Moreover, the positive effects of favorable weather at low conspecific densities were offset by intraspecific competition at high densities. Although realized habitat quality declined with increasing conspecific density suggesting interference mechanisms associated with an Ideal Free Distribution, broad spatial heterogeneity in habitat quality persisted. Factors linked to food resources had positive effects on reproductive output but only where nest cavities were sufficiently abundant to mitigate the negative effects of heterospecific enemies. Annual precipitation and brooding-season temperature had strong multiplicative effects on reproductive output, which declined at increasing rates as drought and temperature increased, reflecting conditions predicted to become more frequent with climate change. Because the collective environment influences habitat quality in complex ways, integrated approaches

  3. Spatial, temporal, and density-dependent components of habitat quality for a desert owl.

    PubMed

    Flesch, Aaron D; Hutto, Richard L; van Leeuwen, Willem J D; Hartfield, Kyle; Jacobs, Sky

    2015-01-01

    Spatial variation in resources is a fundamental driver of habitat quality but the realized value of resources at any point in space may depend on the effects of conspecifics and stochastic factors, such as weather, which vary through time. We evaluated the relative and combined effects of habitat resources, weather, and conspecifics on habitat quality for ferruginous pygmy-owls (Glaucidium brasilianum) in the Sonoran Desert of northwest Mexico by monitoring reproductive output and conspecific abundance over 10 years in and around 107 territory patches. Variation in reproductive output was much greater across space than time, and although habitat resources explained a much greater proportion of that variation (0.70) than weather (0.17) or conspecifics (0.13), evidence for interactions among each of these components of the environment was strong. Relative to habitat that was persistently low in quality, high-quality habitat buffered the negative effects of conspecifics and amplified the benefits of favorable weather, but did not buffer the disadvantages of harsh weather. Moreover, the positive effects of favorable weather at low conspecific densities were offset by intraspecific competition at high densities. Although realized habitat quality declined with increasing conspecific density suggesting interference mechanisms associated with an Ideal Free Distribution, broad spatial heterogeneity in habitat quality persisted. Factors linked to food resources had positive effects on reproductive output but only where nest cavities were sufficiently abundant to mitigate the negative effects of heterospecific enemies. Annual precipitation and brooding-season temperature had strong multiplicative effects on reproductive output, which declined at increasing rates as drought and temperature increased, reflecting conditions predicted to become more frequent with climate change. Because the collective environment influences habitat quality in complex ways, integrated approaches

  4. Effects of regulated river flows on habitat suitability for the robust redhorse

    USGS Publications Warehouse

    Fisk, J. M.; Kwak, Thomas J.; Heise, R. J.

    2015-01-01

    The Robust Redhorse Moxostoma robustum is a rare and imperiled fish, with wild populations occurring in three drainages from North Carolina to Georgia. Hydroelectric dams have altered the species’ habitat and restricted its range. An augmented minimum-flow regime that will affect Robust Redhorse habitat was recently prescribed for Blewett Falls Dam, a hydroelectric facility on the Pee Dee River, North Carolina. Our objective was to quantify suitable spawning and nonspawning habitat under current and proposed minimum-flow regimes. We implanted radio transmitters into 27 adult Robust Redhorses and relocated the fish from spring 2008 to summer 2009, and we described habitat at 15 spawning capture locations. Nonspawning habitat consisted of deep, slow-moving pools (mean depth D 2.3 m; mean velocity D 0.23 m/s), bedrock and sand substrates, and boulders or coarse woody debris as cover. Spawning habitat was characterized as shallower, faster-moving water (mean depth D 0.84 m; mean velocity D 0.61 m/s) with gravel and cobble as substrates and boulders as cover associated with shoals. Telemetry relocations revealed two behavioral subgroups: a resident subgroup (linear range [mean § SE] D 7.9 § 3.7 river kilometers [rkm]) that remained near spawning areas in the Piedmont region throughout the year; and a migratory subgroup (linear range D 64.3 § 8.4 rkm) that migrated extensively downstream into the Coastal Plain region. Spawning and nonspawning habitat suitability indices were developed based on field microhabitat measurements and were applied to model suitable available habitat (weighted usable area) for current and proposed augmented minimum flows. Suitable habitat (both spawning and nonspawning) increased for each proposed seasonal minimum flow relative to former minimum flows, with substantial increases for spawning sites. Our results contribute to an understanding of how regulated flows affect available habitats for imperiled species. Flow managers can use these

  5. Multi-criteria Decision Analysis to Model Ixodes ricinus Habitat Suitability.

    PubMed

    Rousseau, Raphaël; McGrath, Guy; McMahon, Barry J; Vanwambeke, Sophie O

    2017-09-01

    Tick-borne diseases present a major threat to both human and livestock health throughout Europe. The risk of infection is directly related to the presence of its vector. Thereby it is important to know their distribution, which is strongly associated with environmental factors: the presence and availability of a suitable habitat, of a suitable climate and of hosts. The present study models the habitat suitability for Ixodes ricinus in Ireland, where data on tick distribution are scarce. Tick habitat suitability was estimated at a coarse scale (10 km) with a multi-criteria decision analysis (MCDA) method according to four different scenarios (depending on the variables used and on the weights granted to each of them). The western part of Ireland and the Wicklow mountains in the East were estimated to be the most suitable areas for I. ricinus in the island. There was a good level of agreement between results from the MCDA and recorded tick presence. The different scenarios did not affect the spatial outputs substantially. The current study suggests that tick habitat suitability can be mapped accurately at a coarse scale in a data-scarce context using knowledge-based methods. It can serve as a guideline for future countrywide sampling that would help to determine local risk of tick presence and refining knowledge on tick habitat suitability in Ireland.

  6. Colony site dynamics and habitat use in Atlantic coast seabirds

    USGS Publications Warehouse

    Erwin, R.M.; Galli, J.; Burger, J.

    1981-01-01

    Seabird colony sizes and movements were documented in the DelMarVa coastal region in 1976-1977 and in New Jersey in 1978-1979. Most colonies were found on marsh and dredge deposition islands and on barrier island beaches. For the "traditionally" beach-nesting Herring Gull, Common Tern, and Black Skimmer, larger, more stable colonies were found on barrier beaches than on marsh islands. In marsh habitats, rates of colony-site change of marsh-nesting Forster's Tern and Laughing Gulls were similar to those of the former beach nesters. Several adaptations have evolved in marsh specialists to cope with a high risk of reproductive failure due to flooding, but both Herring Gulls and Common Terns also appear to be very adaptable in nesting under various habitat conditions.New colonies and those abandoned between years may be pioneering attempts by younger or inexperienced birds, because they are often smaller than persistent colonies, although patterns differ among areas and habitats. Colony-site dynamics are complex and result from many selective factors including competition, predation, physical changes in site structure, and flooding. The invasion of Herring Gulls into marshes along the mid-Atlantic coast has had an impact on new colony-site choice by associated seabirds.Calculating colony-site turnover rates allows for comparisons among species, habitats, and regions and may give useful insights into habitat quality and change and alternative nesting strategies.

  7. Habitat Suitability Index Models: Yellow-headed blackbird

    USGS Publications Warehouse

    Schroeder, Richard L.

    1982-01-01

    Habitat preferences of the yellow-headed blackbird (Xanthocephalus xanthocephalus) are described in this publication. It is one of a series of Habitat Suitability Index (HSI) models and was developed through an analysis of available infomration on the species-habitat requirements of the species. Habitat use information is presented in a review of the literature, followed by the development of an HSI model, designed for use in impact assessment and habitat management activities.

  8. Brief notes on habitat geology and clay pipe habitat on Stellwagen Bank

    USGS Publications Warehouse

    Valentine, Page C.; Dorsey, Eleanor M.; Pederson, Judith

    1998-01-01

    In our studies of sea floor habitats, my colleagues and I use both biological and geological approaches. We call our studies “habitat geology,” a term coined by a biologist friend of mine. We view it as the study of sea floor materials and biological and geological processes that influence where species live. Some of the factors that we consider are the following:composition of the sea bed, which ranges from mud to sand, gravel, bedrock, and shell beds;shape and steepness of the bottom;roughness of the bottom, which is enhanced by the presence of cobbles, boulders, sand waves and ripples, burrows into the bottom, and species that extend above the bottom;bottom currents generated by storm waves and tides, which can move sediment and expose or cover habitats; andthe way in which the sea bed is utilized by species.In addition, we take into account the impact of sea bed disturbance by bottom fishing trawls and dredges. Habitats characterized by attached and burrowing species that protrude above the sea bed appear to be most vulnerable to disturbance.

  9. Telemetry-Determined Habitat Use Informs Multi-Species Habitat Management in an Urban Harbour.

    PubMed

    Rous, Andrew M; Midwood, Jonathon D; Gutowsky, Lee F G; Lapointe, Nicolas W R; Portiss, Rick; Sciscione, Thomas; Wells, Mathew G; Doka, Susan E; Cooke, Steven J

    2017-01-01

    Widespread human development has led to impairment of freshwater coastal wetlands and embayments, which provide critical and unique habitat for many freshwater fish species. This is particularly evident in the Laurentian Great Lakes, where such habitats have been severely altered over the last century as a result of industrial activities, urbanization, dredging and infilling. In Toronto Harbour, extensive restoration efforts have been directed towards improving the amount and quality of aquatic habitat, especially for fishes. To evaluate the effectiveness of this restoration work, use of the restored area by both target species and the fish community as a whole must be assessed. Individuals from four species (Common Carp, Largemouth Bass, Northern Pike and Yellow Perch) were tagged and tracked continuously for 1 year using an acoustic telemetry array in Toronto Harbour area of Lake Ontario. Daily site fidelity was estimated using a mixed-effects logistic regression model. Daily site fidelity was influenced by habitat restoration and its interactions with species and body size, as well as season and its interactions with species and body size. Daily site fidelity was higher in restored sites compared to non-restored sites for Yellow Perch and Northern Pike, but lower for Largemouth Bass and Common Carp. For all species, daily site fidelity estimates were highest during the summer and lowest during autumn. The approach used here has merit for evaluating restoration success and informing future habitat management activities. Creating diverse habitats that serve multiple functions and species are more desirable than single-function-oriented or single-species-oriented designs.

  10. Telemetry-Determined Habitat Use Informs Multi-Species Habitat Management in an Urban Harbour

    NASA Astrophysics Data System (ADS)

    Rous, Andrew M.; Midwood, Jonathon D.; Gutowsky, Lee F. G.; Lapointe, Nicolas W. R.; Portiss, Rick; Sciscione, Thomas; Wells, Mathew G.; Doka, Susan E.; Cooke, Steven J.

    2017-01-01

    Widespread human development has led to impairment of freshwater coastal wetlands and embayments, which provide critical and unique habitat for many freshwater fish species. This is particularly evident in the Laurentian Great Lakes, where such habitats have been severely altered over the last century as a result of industrial activities, urbanization, dredging and infilling. In Toronto Harbour, extensive restoration efforts have been directed towards improving the amount and quality of aquatic habitat, especially for fishes. To evaluate the effectiveness of this restoration work, use of the restored area by both target species and the fish community as a whole must be assessed. Individuals from four species (Common Carp, Largemouth Bass, Northern Pike and Yellow Perch) were tagged and tracked continuously for 1 year using an acoustic telemetry array in Toronto Harbour area of Lake Ontario. Daily site fidelity was estimated using a mixed-effects logistic regression model. Daily site fidelity was influenced by habitat restoration and its interactions with species and body size, as well as season and its interactions with species and body size. Daily site fidelity was higher in restored sites compared to non-restored sites for Yellow Perch and Northern Pike, but lower for Largemouth Bass and Common Carp. For all species, daily site fidelity estimates were highest during the summer and lowest during autumn. The approach used here has merit for evaluating restoration success and informing future habitat management activities. Creating diverse habitats that serve multiple functions and species are more desirable than single-function-oriented or single-species-oriented designs.

  11. Lyme borreliosis habitat assessment.

    PubMed

    Gray, J S; Kahl, O; Robertson, J N; Daniel, M; Estrada-Peña, A; Gettinby, G; Jaenson, T G; Jensen, P; Jongejan, F; Korenberg, E; Kurtenbach, K; Zeman, P

    1998-03-01

    Tick ecologists throughout Europe provided descriptions of Lyme borreliosis habitats according to a standardised format and data for 105 habitats in 16 countries were received. The data showed that high risk situations, as defined by the presence of large numbers of B. burgdorferi sensu lato-infected nymphal I. ricinus, occur in heterogeneous deciduous woodland, usually with a recreational function and with a diverse fauna, usually including deer. Large numbers of ticks occurred in some other habitats, but infection prevalence was usually low. The situation for adult I. ricinus was similar but less clearly defined. Tick infection rates were found to be lower in western Europe than in the east, and the infection rate in I. persulcatus, the most easterly vector species, was markedly higher than in I. ricinus. In the vast majority of habitats the infection rate in adult I. ricinus was greater than in nymphs. Larvae were rarely found to be infected.

  12. Habitat Selection and Risk of Predation: Re-colonization by Lynx had Limited Impact on Habitat Selection by Roe Deer

    PubMed Central

    Samelius, Gustaf; Andrén, Henrik; Kjellander, Petter; Liberg, Olof

    2013-01-01

    Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx – the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1) before and after lynx re-established in the study area and (2) in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection). Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations. PMID:24069419

  13. Habitat selection and risk of predation: re-colonization by lynx had limited impact on habitat selection by roe deer.

    PubMed

    Samelius, Gustaf; Andrén, Henrik; Kjellander, Petter; Liberg, Olof

    2013-01-01

    Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx - the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1) before and after lynx re-established in the study area and (2) in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection). Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations.

  14. Bird Communities of the Arctic Shrub Tundra of Yamal: Habitat Specialists and Generalists

    PubMed Central

    Sokolov, Vasiliy; Ehrich, Dorothée; Yoccoz, Nigel G.; Sokolov, Alexander; Lecomte, Nicolas

    2012-01-01

    Background The ratio of habitat generalists to specialists in birds has been suggested as a good indicator of ecosystem changes due to e.g. climate change and other anthropogenic perturbations. Most studies focusing on this functional component of biodiversity originate, however, from temperate regions. The Eurasian Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by domestic reindeer and growing human activity. Methodology/Principal Findings Here we monitored bird communities in a tundra landscape harbouring shrub and open habitats in order to analyse bird habitat relationships and quantify habitat specialization. We used ordination methods to analyse habitat associations and estimated the proportions of specialists in each of the main habitats. Correspondence Analysis identified three main bird communities, inhabiting upland, lowland and dense willow shrubs. We documented a stable structure of communities despite large multiannual variations of bird density (from 90 to 175 pairs/km2). Willow shrub thickets were a hotspot for bird density, but not for species richness. The thickets hosted many specialized species whose main distribution area was south of the tundra. Conclusion/Significance If current arctic changes result in a shrubification of the landscape as many studies suggested, we would expect an increase in the overall bird abundance together with an increase of local specialists, since they are associated with willow thickets. The majority of these species have a southern origin and their increase in abundance would represent a strengthening of the boreal component in the southern tundra, perhaps at the expense of species typical of the subarctic zone, which appear to be generalists within this zone. PMID:23239978

  15. Habitat selection of Rocky Mountain elk in a nonforested environment

    USGS Publications Warehouse

    Sawyer, H.; Nielson, R.M.; Lindzey, F.G.; Keith, L.; Powell, J.H.; Abraham, A.A.

    2007-01-01

    Recent expansions by Rocky Mountain elk (Cervus elaphus) into nonforested habitats across the Intermountain West have required managers to reconsider the traditional paradigms of forage and cover as they relate to managing elk and their habitats. We examined seasonal habitat selection patterns of a hunted elk population in a nonforested high-desert region of southwestern Wyoming, USA. We used 35,246 global positioning system locations collected from 33 adult female elk to model probability of use as a function of 6 habitat variables: slope, aspect, elevation, habitat diversity, distance to shrub cover, and distance to road. We developed resource selection probability functions for individual elk, and then we averaged the coefficients to estimate population-level models for summer and winter periods. We used the population-level models to generate predictive maps by assigning pixels across the study area to 1 of 4 use categories (i.e., high, medium-high, medium-low, or low), based on quartiles of the predictions. Model coefficients and predictive maps indicated that elk selected for summer habitats characterized by higher elevations in areas of high vegetative diversity, close to shrub cover, northerly aspects, moderate slopes, and away from roads. Winter habitat selection patterns were similar, except elk shifted to areas with lower elevations and southerly aspects. We validated predictive maps by using 528 locations collected from an independent sample of radiomarked elk (n = 55) and calculating the proportion of locations that occurred in each of the 4 use categories. Together, the high- and medium-high use categories of the summer and winter predictive maps contained 92% and 74% of summer and winter elk locations, respectively. Our population-level models and associated predictive maps were successful in predicting winter and summer habitat use by elk in a nonforested environment. In the absence of forest cover, elk seemed to rely on a combination of shrubs

  16. Big Spring spinedace and associated fish populations and habitat conditions in Condor Canyon, Meadow Valley Wash, Nevada

    USGS Publications Warehouse

    Jezorek, Ian G.; Connolly, Patrick J.; Munz, Carrie S.; Dixon, Chris

    2011-01-01

    Executive Summary: This project was designed to document habitat conditions and populations of native and non-native fish within the 8-kilometer Condor Canyon section of Meadow Valley Wash, Nevada, with an emphasis on Big Spring spinedace (Lepidomeda mollispinis pratensis). Other native fish present were speckled dace (Rhinichthys osculus) and desert sucker (Catostomus clarki). Big Spring spinedace were known to exist only within this drainage and were known to have been extirpated from a portion of their former habitat located downstream of Condor Canyon. Because of this extirpation and the limited distribution of Big Spring spinedace, the U.S. Fish and Wildlife Service listed this species as threatened under the Endangered Species Act in 1985. Prior to our effort, little was known about Big Spring spinedace populations or life histories and habitat associations. In 2008, personnel from the U.S. Geological Survey's Columbia River Research Laboratory began surveys of Meadow Valley Wash in Condor Canyon. Habitat surveys characterized numerous variables within 13 reaches, thermologgers were deployed at 9 locations to record water temperatures, and fish populations were surveyed at 22 individual sites. Additionally, fish were tagged with Passive Integrated Transponder (PIT) tags, which allowed movement and growth information to be collected on individual fish. The movements of tagged fish were monitored with a combination of recapture events and stationary in-stream antennas, which detected tagged fish. Meadow Valley Wash within Condor Canyon was divided by a 12-meter (m) waterfall known as Delmue Falls. About 6,100 m of stream were surveyed downstream of the falls and about 2,200 m of stream were surveyed upstream of the falls. Although about three-quarters of the surveyed stream length was downstream of Delmue Falls, the highest densities and abundance of native fish were upstream of the falls. Big Spring spinedace and desert sucker populations were highest near the

  17. Future land-use scenarios and the loss of wildlife habitats in the southeastern United States.

    PubMed

    Martinuzzi, Sebastián; Withey, John C; Pidgeon, Anna M; Plantinga, Andrew J; McKerrow, Alexa J; Williams, Steven G; Helmers, David P; Radeloff, Volker C

    2015-01-01

    Land-use change is a major cause of wildlife habitat loss. Understanding how changes in land-use policies and economic factors can impact future trends in land use and wildlife habitat loss is therefore critical for conservation efforts. Our goal here was to evaluate the consequences of future land-use changes under different conservation policies and crop market conditions on habitat loss for wildlife species in the southeastern United States. We predicted the rates of habitat loss for 336 terrestrial vertebrate species by 2051. We focused on habitat loss due to the expansion of urban, crop, and pasture. Future land-use changes following business-as-usual conditions resulted in relatively low rates of wildlife habitat loss across the entire Southeast, but some ecoregions and species groups experienced much higher habitat loss than others. Increased crop commodity prices exacerbated wildlife habitat loss in most ecoregions, while the implementation of conservation policies (reduced urban sprawl, and payments for land conservation) reduced the projected habitat loss in some regions, to a certain degree. Overall, urban and crop expansion were the main drivers of habitat loss. Reptiles and wildlife species associated with open vegetation (grasslands, open woodlands) were the species groups most vulnerable to future land-use change. Effective conservation of wildlife habitat in the Southeast should give special consideration to future land-use changes, regional variations, and the forces that could shape land-use decisions.

  18. Future land-use scenarios and the loss of wildlife habitats in the southeastern United States

    USGS Publications Warehouse

    Martinuzzi, Sebastián; Withey, John C.; Pidgeon, Anna M.; Plantinga, Andrew; McKerrow, Alexa; Williams, Steven G.; Helmers, David P.; Radeloff, Volker C.

    2015-01-01

    Land-use change is a major cause of wildlife habitat loss. Understanding how changes in land-use policies and economic factors can impact future trends in land use and wildlife habitat loss is therefore critical for conservation efforts. Our goal here was to evaluate the consequences of future land-use changes under different conservation policies and crop market conditions on habitat loss for wildlife species in the southeastern United States. We predicted the rates of habitat loss for 336 terrestrial vertebrate species by 2051. We focused on habitat loss due to the expansion of urban, crop, and pasture. Future land-use changes following business-as-usual conditions resulted in relatively low rates of wildlife habitat loss across the entire Southeast, but some ecoregions and species groups experienced much higher habitat loss than others. Increased crop commodity prices exacerbated wildlife habitat loss in most ecoregions, while the implementation of conservation policies (reduced urban sprawl, and payments for land conservation) reduced the projected habitat loss in some regions, to a certain degree. Overall, urban and crop expansion were the main drivers of habitat loss. Reptiles and wildlife species associated with open vegetation (grasslands, open woodlands) were the species groups most vulnerable to future land-use change. Effective conservation of wildlife habitat in the Southeast should give special consideration to future land-use changes, regional variations, and the forces that could shape land-use decisions.

  19. Seasonal variation in coastal marine habitat use by the European shag: Insights from fine scale habitat selection modeling and diet

    NASA Astrophysics Data System (ADS)

    Michelot, Candice; Pinaud, David; Fortin, Matthieu; Maes, Philippe; Callard, Benjamin; Leicher, Marine; Barbraud, Christophe

    2017-07-01

    Studies of habitat selection by higher trophic level species are necessary for using top predator species as indicators of ecosystem functioning. However, contrary to terrestrial ecosystems, few habitat selection studies have been conducted at a fine scale for coastal marine top predator species, and fewer have coupled diet data with habitat selection modeling to highlight a link between prey selection and habitat use. The aim of this study was to characterize spatially and oceanographically, at a fine scale, the habitats used by the European Shag Phalacrocorax aristotelis in the Special Protection Area (SPA) of Houat-Hœdic in the Mor Braz Bay during its foraging activity. Habitat selection models were built using in situ observation data of foraging shags (transect sampling) and spatially explicit environmental data to characterize marine benthic habitats. Observations were first adjusted for detectability biases and shag abundance was subsequently spatialized. The influence of habitat variables on shag abundance was tested using Generalized Linear Models (GLMs). Diet data were finally confronted to habitat selection models. Results showed that European shags breeding in the Mor Braz Bay changed foraging habitats according to the season and to the different environmental and energetic constraints. The proportion of the main preys also varied seasonally. Rocky and coarse sand habitats were clearly preferred compared to fine or muddy sand habitats. Shags appeared to be more selective in their foraging habitats during the breeding period and the rearing of chicks, using essentially rocky areas close to the colony and consuming preferentially fish from the Labridae family and three other fish families in lower proportions. During the post-breeding period shags used a broader range of habitats and mainly consumed Gadidae. Thus, European shags seem to adjust their feeding strategy to minimize energetic costs, to avoid intra-specific competition and to maximize access

  20. Bacterial Community Variation in Human Body Habitats Across Space and Time

    PubMed Central

    Costello, Elizabeth K.; Lauber, Christian L.; Hamady, Micah; Fierer, Noah; Gordon, Jeffrey I.; Knight, Rob

    2010-01-01

    Elucidating the biogeography of bacterial communities on the human body is critical for establishing healthy baselines from which to detect differences associated with diseases. To obtain an integrated view of the spatial and temporal distribution of the human microbiota, we surveyed bacteria from up to 27 sites in 7–9 healthy adults on four occasions. We found that community composition was determined primarily by body habitat. Within habitats, interpersonal variability was high, while individuals exhibited minimal temporal variability. Several skin locations harbored more diverse communities than the gut and mouth, and skin locations differed in their community assembly patterns. These results indicate that our microbiota, although personalized, varies systematically across body habitats and time: such trends may ultimately reveal how microbiome changes cause or prevent disease. PMID:19892944

  1. Habitat Suitability Index Models: Red-winged blackbird

    USGS Publications Warehouse

    Short, Henry L.

    1985-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the red-winged blackbird (Agelaius phoeniceus L.). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  2. Forest fire impact on bird habitat in a mixed oak-pine forest in Puebla, Mexico

    Treesearch

    Laura P. Ponce-Calderón Ponce-Calderón; Dante A. Rodríguez-Trejo; Beatriz C. Aguilar-Váldez; Elvia López-Pérez

    2013-01-01

    To assess the impact of different-severity wildfires on bird habitat, habitat quality was determined by analyzing the degree of richness association, abundance and diversity of bird species and vegetation structure (richness, abundance, diversity and coverage). These attributes were quantified with four sampling sites for birds and five for quadrant-centered points...

  3. Habitat Demonstration Unit-Deep Space Habitat (HDU-DSH) Integration and Preparation for Desert RATS 2011

    NASA Technical Reports Server (NTRS)

    Barbeau, Zack

    2011-01-01

    The Habitat Demonstration Unit, or HDU, is a multi-purpose test bed that allows NASA scientists and engineers to design, develop, and test new living quarters, laboratories, and workspaces for the next generation space mission. Previous testing and integration has occurred during 2010 at the annual Desert Research and Technology Studies (Desert RATS) field testing campaign in the Arizona desert. There the HDU team tests the configuration developed for the fiscal year, or FY configuration. For FY2011, the NASA mission calls for simulating a deep space condition. The HDU-DSH, or Deep Space Habitat, will be configured with new systems and modules that will outfit the test bed with new deep space capabilities. One such addition is the new X-HAB (eXploration Habitat) Inflatable Loft. With any deep space mission there is the need for safe, suitable living quarters. The current HDU configuration does not allow for any living space at all. In fact, Desert RATS 2010 saw the crew sleeping in the Space Exploration Vehicles (SEV) instead of the HDU. The X-HAB Challenge pitted three universities against each other: Oklahoma State University, University of Maryland, and the University of Wisconsin. The winning team will have their design implemented by NASA for field testing at DRATS 2011. This paper will highlight the primary objective of getting the X-HAB field ready which involves the implementation of an elevator/handrail system along with smaller logistical and integration tasks associated with getting the HDU-DSH ready for shipment to DRATS.

  4. Testing projected wild bee distributions in agricultural habitats: predictive power depends on species traits and habitat type.

    PubMed

    Marshall, Leon; Carvalheiro, Luísa G; Aguirre-Gutiérrez, Jesús; Bos, Merijn; de Groot, G Arjen; Kleijn, David; Potts, Simon G; Reemer, Menno; Roberts, Stuart; Scheper, Jeroen; Biesmeijer, Jacobus C

    2015-10-01

    Species distribution models (SDM) are increasingly used to understand the factors that regulate variation in biodiversity patterns and to help plan conservation strategies. However, these models are rarely validated with independently collected data and it is unclear whether SDM performance is maintained across distinct habitats and for species with different functional traits. Highly mobile species, such as bees, can be particularly challenging to model. Here, we use independent sets of occurrence data collected systematically in several agricultural habitats to test how the predictive performance of SDMs for wild bee species depends on species traits, habitat type, and sampling technique. We used a species distribution modeling approach parametrized for the Netherlands, with presence records from 1990 to 2010 for 193 Dutch wild bees. For each species, we built a Maxent model based on 13 climate and landscape variables. We tested the predictive performance of the SDMs with independent datasets collected from orchards and arable fields across the Netherlands from 2010 to 2013, using transect surveys or pan traps. Model predictive performance depended on species traits and habitat type. Occurrence of bee species specialized in habitat and diet was better predicted than generalist bees. Predictions of habitat suitability were also more precise for habitats that are temporally more stable (orchards) than for habitats that suffer regular alterations (arable), particularly for small, solitary bees. As a conservation tool, SDMs are best suited to modeling rarer, specialist species than more generalist and will work best in long-term stable habitats. The variability of complex, short-term habitats is difficult to capture in such models and historical land use generally has low thematic resolution. To improve SDMs' usefulness, models require explanatory variables and collection data that include detailed landscape characteristics, for example, variability of crops and

  5. Comparison of macroinvertebrate-derived stream quality metrics between snag and riffle habitats

    USGS Publications Warehouse

    Stepenuck, K.F.; Crunkilton, R.L.; Bozek, Michael A.; Wang, L.

    2008-01-01

    We compared benthic macroinvertebrate assemblage structure at snag and riffle habitats in 43 Wisconsin streams across a range of watershed urbanization using a variety of stream quality metrics. Discriminant analysis indicated that dominant taxa at riffles and snags differed; Hydropsychid caddisflies (Hydropsyche betteni and Cheumatopsyche spp.) and elmid beetles (Optioservus spp. and Stenemlis spp.) typified riffles, whereas isopods (Asellus intermedius) and amphipods (Hyalella azteca and Gammarus pseudolimnaeus) predominated in snags. Analysis of covariance indicated that samples from snag and riffle habitats differed significantly in their response to the urbanization gradient for the Hilsenhoff biotic index (BI), Shannon's diversity index, and percent of filterers, shredders, and pollution intolerant Ephemeroptera, Plecoptera, and Trichoptera (EPT) at each stream site (p ??? 0.10). These differences suggest that although macroinvertebrate assemblages present in either habitat type are sensitive to detecting the effects of urbanization, metrics derived from different habitats should not be intermixed when assessing stream quality through biomonitoring. This can be a limitation to resource managers who wish to compare water quality among streams where the same habitat type is not available at all stream locations, or where a specific habitat type (i.e., a riffle) is required to determine a metric value (i.e., BI). To account for differences in stream quality at sites lacking riffle habitat, snag-derived metric values can be adjusted based on those obtained from riffles that have been exposed to the same level of urbanization. Comparison of nonlinear regression equations that related stream quality metric values from the two habitat types to percent watershed urbanization indicated that snag habitats had on average 30.2 fewer percent EPT individuals, a lower diversity index value than riffles, and a BI value of 0.29 greater than riffles. ?? 2008 American Water

  6. Keeping Pace with Climate Change: Habitat Protection in the Face of Uncertainty

    NASA Astrophysics Data System (ADS)

    Flitcroft, R. L.; Burnett, K.; Giannico, G.

    2014-12-01

    Estuaries provide critical habitat for many economically and culturally important species. In the Pacific Northwest, intertidal and subtidal areas provide critical habitat for production of native and commercial oysters (Olympia oyster Ostrea lurida and Pacific oyster Crassostrea gigas, respectively) that in turn provide refuge and rearing habitat for Dungeness Crab, Metacarcinus magister. Environments ranging from subtidal through freshwater zones provide nursery areas for juvenile salmonids at different development stages in their life history. Most Oregon estuaries have been significantly altered by humans over the past century, reducing the quantity and diversity of available habitats. Management agencies have responded with projects to restore and enhance estuarine habitats. Unfortunately, future climate change and sea-level rise could render many current restoration projects ineffective over time. Planning for habitat restoration that keeps pace with climate change will be critical to the sustainable production of seafood and maintenance of ecosystem function. However, land managers and citizens lack the spatially-explicit data needed to incorporate the potential effects of climate change and sea-level rise into planning for habitat improvement projects in estuarine areas. To meet this need, we developed simple models using LiDAR to characterize the geomorphologies of multiple Oregon estuaries. We were able to map the margin of current mean high tide, and contour intervals associated with different potential increases in mean high tide. Because our analysis relied on digital data, we compared three types of digital data in one estuary to assess the utility of different data sets in predicting changes in estuary shape. For each estuary, we assessed changes in the amount and complexity of edge habitats. The simple modeling approach we applied can also be used to identify areas that may be most amenable to pre-emptive restoration actions to mitigate or enhance

  7. Lower Columbia River and Estuary Habitat Monitoring Study, 2011 - Final Report

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

    Borde, Amy B.; Kaufmann, Ronald M.; Cullinan, Valerie I.

    The Ecosystem Monitoring Program is a collaborative effort between the Lower Columbia River Estuary Partnership (LCREP), University of Washington, Wetland Ecosystem Team (UW), US Geological Survey, Water Science Center (USGS), National Oceanic and Atmospheric Administration, National Marine Fisheries Service (NOAA-Fisheries, hereafter NOAA), and Pacific Northwest National Laboratory, Marine Sciences Laboratory (PNNL). The goal of the program is to conduct emergent wetland monitoring aimed at characterizing salmonid habitats in the lower Columbia River and estuary (LCRE) from the mouth of the estuary to Bonneville Dam (Figure 1). This is an ecosystem based monitoring program focused on evaluating status and trends inmore » habitat and reducing uncertainties regarding these ecosystems to ultimately improve the survival of juvenile salmonids through the LCRE. This project comprehensively assesses habitat, fish, food web, and abiotic conditions in the lower river, focusing on shallow water and vegetated habitats used by juvenile salmonids for feeding, rearing and refugia. The information is intended to be used to guide management actions associated with species recovery, particularly that of threatened and endangered salmonids. PNNL’s role in this multi-year study is to monitor the habitat structure (e.g., vegetation, topography, channel morphology, and sediment type) as well as hydrologic patterns.« less

  8. 50 CFR 17.94 - Critical habitats.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the listed species within these defined Critical Habitats. (See part 402 for rules concerning this prohibition; see also part 424 for rules concerning the determination of Critical Habitat). (b) The map... of a Critical Habitat. Such maps are provided for reference purposes to guide Federal agencies and...

  9. Ontogenetic and diel variation in stream habitat use by brook trout (Salvelinus fontinalis) in a headwater stream

    USGS Publications Warehouse

    Johnson, J. H.; Ross, R.M.; Dropkin, D.S.; Redell, L.A.

    2011-01-01

    Although considerable information exists on habitat use by stream salmonids, only a small portion has quantitatively examined diurnal and nocturnal habitat variation. We examined diel variation in habitat use by age-0 and age-1+ brook trout (Salvelinus fontinalis) during summer and autumn in a headwater stream in northern Pennsylvania. Habitat variables measured included cover, depth, substrate, and velocity. The most pronounced diel variation occurred in the use of cover during both seasons. Both age-0 brook trout and age-1+ trout were associated with less cover at night. Age-0 brook trout occupied swifter water during the day than at night during both seasons, but the difference was not significant. Increased cover, depth, and substrate size governed the habitat of age-1+ brook trout. Our findings support the need for a better understanding of diel differences in habitat use of stream salmonids when considering habitat enhancement and protection.

  10. Feeding habitats of nesting wading birds: Spatial use and social influences

    USGS Publications Warehouse

    Erwin, R. Michael

    1983-01-01

    In an effort to relate social interactions to feeding-habitat use, I observed six species of wading birds near a major colony site in coastal North Carolina. Three spatial scales of habitat use were considered: the general orientation to and from the colony (coarsest level), the habitat "patch," and (at the finest level) the microhabitat. Departure-arrival directions of Great Egrets (Casmerodius albus), Snowy Egrets (Egretta thula), Cattle Egrets (Bubulcus ibis), Little Blue Herons (Egretta caerulea), Tricolored Herons (Egretta tricolor), and Glossy Ibises (Plegadis falcinellus) were monitored at the colony site to document coarse patterns of feeding-habitat use. Added to these data were observations made at five different wetland sites to monitor between-habitat and within-habitat patterns for the five aquatic-feeding species. The results indicated a broad and variable use of feeding habitat over time. At the coarsest scale (i.e. orientation at the colony), diffuse patterns, influenced little by either inter- or intraspecific social interaction, were found for all species. At the next level (habitat "patch"), only one of five wetland sites was relatively consistent in attracting feeding birds, and its use increased from May to June. Few groups were seen at four of the five sites. At the one "attractive" site, the within-habitat patterns again were spatially variable over time, except for those of the abundant Snowy Egret, whose microhabitat preference was fairly consistent. Glossy Ibises and Snowy Egrets frequently formed mixed-species groups, Little Blue Herons were the least social, and Great Egrets and Tricolored Herons generally occurred in groups of less than 10 birds but rarely in groups larger than 30. The close association between Snowy Egrets and Glossy Ibises appeared to be based on a "beater-follower" relationship, wherein the probing, nonvisually feeding ibises make prey more available to the followers. In the study area, local enhancement appeared to

  11. 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.

  12. Tests of wildlife habitat models to evaluate oak-mast production

    USGS Publications Warehouse

    Schroeder, R.L.; Vangilder, L.D.

    1997-01-01

    We measured oak-mast production and forest structure and composition in the Ozark Mountains of Missouri and tested the accuracy of oak-mast prediction variables from 5 Habitat Suitability Index (HSI) species models. Acorn production was positively associated with several measures of abundance and canopy cover of oak trees, and with an index of mast production for all 5 HSI models. We developed 2 modified oak-mast models, based on inputs related to either oak tree density or oak canopy cover and diversity of oak tree species. The revised models accounted for 22-32% of the variance associated with acorn abundance. Future tests of HSI models should consider: (1) the concept of upper limits imposed by habitat and the effects of nonhabitat factors; (2) the benefits of a top-down approach to model development; and (3) testing models across broad geographic regions.

  13. Wildlife Habitat Evaluation Handbook.

    ERIC Educational Resources Information Center

    Neilson, Edward L., Jr.; Benson, Delwin E.

    The National 4-H Wildlife Invitational is a competitive event to teach youth about the fundamentals of wildlife management. Youth learn that management for wildlife means management of wildlife habitat and providing for the needs of wildlife. This handbook provides information about wildlife habitat management concepts in both urban and rural…

  14. Forest succession on four habitat types in western Montana

    Treesearch

    Stephen F. Arno; Dennis G. Simmerman; Robert E. Keane

    1985-01-01

    Presents classifications of successional community types on four major forest habitat types in western Montana. Classifications show the sequences of seral community types developing after stand-replacing wildfire and clearcutting with broadcast burning, mechanical scarification, or no followup treatment. Information is provided for associating vegetational response to...

  15. The phylogenetic structure of plant-pollinator networks increases with habitat size and isolation.

    PubMed

    Aizen, Marcelo A; Gleiser, Gabriela; Sabatino, Malena; Gilarranz, Luis J; Bascompte, Jordi; Verdú, Miguel

    2016-01-01

    Similarity among species in traits related to ecological interactions is frequently associated with common ancestry. Thus, closely related species usually interact with ecologically similar partners, which can be reinforced by diverse co-evolutionary processes. The effect of habitat fragmentation on the phylogenetic signal in interspecific interactions and correspondence between plant and animal phylogenies is, however, unknown. Here, we address to what extent phylogenetic signal and co-phylogenetic congruence of plant-animal interactions depend on habitat size and isolation by analysing the phylogenetic structure of 12 pollination webs from isolated Pampean hills. Phylogenetic signal in interspecific interactions differed among webs, being stronger for flower-visiting insects than plants. Phylogenetic signal and overall co-phylogenetic congruence increased independently with hill size and isolation. We propose that habitat fragmentation would erode the phylogenetic structure of interaction webs. A decrease in phylogenetic signal and co-phylogenetic correspondence in plant-pollinator interactions could be associated with less reliable mutualism and erratic co-evolutionary change. © 2015 John Wiley & Sons Ltd/CNRS.

  16. Salmon River Habitat Enhancement. 1990 Annual Report

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

    Rowe, Mike

    1991-12-01

    The annual report contains three individual subproject sections detailing tribal fisheries work completed during the summer and fall of 1990. Subproject I contains summaries of evaluation/monitoring efforts associated with the Bear Valley Creek, Idaho enhancement project. Subproject II contains an evaluation of the Yankee Fork of the Salmon River habitat enhancement project. Subproject III concerns the East Fork of the Salmon River, Idaho.

  17. Anthropogenic habitat disturbance and ecological divergence between incipient species of the malaria mosquito Anopheles gambiae.

    PubMed

    Kamdem, Colince; Tene Fossog, Billy; Simard, Frédéric; Etouna, Joachim; Ndo, Cyrille; Kengne, Pierre; Boussès, Philippe; Etoa, François-Xavier; Awono-Ambene, Parfait; Fontenille, Didier; Antonio-Nkondjio, Christophe; Besansky, Nora J; Costantini, Carlo

    2012-01-01

    Anthropogenic habitat disturbance is a prime cause in the current trend of the Earth's reduction in biodiversity. Here we show that the human footprint on the Central African rainforest, which is resulting in deforestation and growth of densely populated urban agglomerates, is associated to ecological divergence and cryptic speciation leading to adaptive radiation within the major malaria mosquito Anopheles gambiae. In southern Cameroon, the frequency of two molecular forms--M and S--among which reproductive isolation is strong but still incomplete, was correlated to an index of urbanisation extracted from remotely sensed data, expressed as the proportion of built-up surface in each sampling unit. The two forms markedly segregated along an urbanisation gradient forming a bimodal cline of ∼6-km width: the S form was exclusive to the rural habitat, whereas only the M form was present in the core of densely urbanised settings, co-occurring at times in the same polluted larval habitats of the southern house mosquito Culex quinquefasciatus--a species association that was not historically recorded before. Our results indicate that when humans create novel habitats and ecological heterogeneities, they can provide evolutionary opportunities for rapid adaptive niche shifts associated with lineage divergence, whose consequences upon malaria transmission might be significant.

  18. Interspecific variation in hypoxia tolerance, swimming performance and plasticity in cyprinids that prefer different habitats.

    PubMed

    Fu, Shi-Jian; Fu, Cheng; Yan, Guan-Jie; Cao, Zhen-Dong; Zhang, An-Jie; Pang, Xu

    2014-02-15

    This study quantified and compared hypoxia tolerance and swim performance among cyprinid fish species from rapid-, slow- and intermediate-flow habitats (four species per habitat) in China. In addition, we explored the effects of short-term acclimation on swim performance, maximum metabolic rate (M(O2,max)) and gill remodelling to detect habitat-associated patterns of plastic response to hypoxia. Indices of hypoxia tolerance included oxygen threshold for loss of equilibrium (LOE50) and aquatic surface respiration (ASR50), and critical oxygen tension for routine metabolic rate (Pcrit). Critical swimming speed (Ucrit) and M(O2,max) were measured under normoxic and hypoxic conditions after 48 h acclimation to normoxia and hypoxia, and gill remodelling was estimated after 48 h of hypoxia exposure. Both traditional ANCOVA and phylogenetically independent contrast (PDANOVA) analyses showed that fish species from rapid-flow habitats exhibited lower LOE50 compared with fish from intermediate- and slow-flow habitats. Habitat-specific differences in Pcrit and Ucrit were detected using PDANOVA but not traditional ANCOVA analyses, with fish species from rapid-flow habitats exhibiting lower Pcrit but higher Ucrit values compared with fish from intermediate- and slow-flow habitats. Fish species from rapid-flow habitats were also characterized by less plasticity in swim performance and gill morphology in response to hypoxia acclimation compared with species from slow-flow habitats, but a greater drop in swim performance in response to acute hypoxia exposure. The study detected a habitat-specific difference in hypoxia tolerance, swimming performance and its plasticity among fish from habitats with different flow conditions, possibly because of the long-term adaptation to the habitat caused by selection stress. The PDANOVA analyses were more powerful than traditional statistical analyses according to the habitat effects in both hypoxia tolerance and swimming performance in this

  19. Simulating the influences of various fire regimes on caribou winter habitat

    USGS Publications Warehouse

    Rupp, T. Scott; Olson, Mark; Adams, Layne G.; Dale, Bruce W.; Joly, Kyle; Henkelman, Jonathan; Collins, William B.; Starfield, Anthony M.

    2006-01-01

    Caribou are an integral component of high‐latitude ecosystems and represent a major subsistence food source for many northern people. The availability and quality of winter habitat is critical to sustain these caribou populations. Caribou commonly use older spruce woodlands with adequate terrestrial lichen, a preferred winter forage, in the understory. Changes in climate and fire regime pose a significant threat to the long‐term sustainability of this important winter habitat. Computer simulations performed with a spatially explicit vegetation succession model (ALFRESCO) indicate that changes in the frequency and extent of fire in interior Alaska may substantially impact the abundance and quality of winter habitat for caribou. We modeled four different fire scenarios and tracked the frequency, extent, and spatial distribution of the simulated fires and associated changes to vegetation composition and distribution. Our results suggest that shorter fire frequencies (i.e., less time between recurring fires) on the winter range of the Nelchina caribou herd in eastern interior Alaska will result in large decreases of available winter habitat, relative to that currently available, in both the short and long term. A 30% shortening of the fire frequency resulted in a 3.5‐fold increase in the area burned annually and an associated 41% decrease in the amount of spruce–lichen forest found on the landscape. More importantly, simulations with more frequent fires produced a relatively immature forest age structure, compared to that which currently exists, with few stands older than 100 years. This age structure is at the lower limits of stand age classes preferred by caribou from the Nelchina herd. Projected changes in fire regime due to climate warming and/or additional prescribed burning could substantially alter the winter habitat of caribou in interior Alaska and lead to changes in winter range use and/or population dynamics.

  20. Predator identity influences the effect of habitat management on nest predation.

    PubMed

    Lyons, Timothy P; Miller, James R; Debinski, Diane M; Engle, David M

    2015-09-01

    Predation is the leading cause of nest failure for many passerines and considerable effort is devoted to identifying the habitat characteristics and management practices that influence nest loss. The habitat components associated with nest loss are strongly influenced by the ecology of nest predators and differ among predator species as a result. Nevertheless, there is a tendency to generalize about the effects of habitat features and management on nest failure without considering how resulting patterns are influenced by nest predators. We examined how predator-specific patterns of nest loss differed among predators and in response to grassland management with fire and grazing by cattle (Bos taurus). We used video cameras to monitor and identify predators at nests of the Grasshopper Sparrow (Ammodramus savannarum), a species of conservation concern throughout its range. We observed predation by 15 different species that differed in their response to management and the habitat characteristics associated with nests they preyed on. Losses to mammals and snakes were more likely at nests with greater amounts of litter cover and tall fescue (Schedonorus phoenix). Mammals were less likely to prey on nests surrounded by greater forb cover. Nest predation by snakes was lower in burned areas, whereas predation by mammals and Brown-headed Cowbirds (Molothrus ater) was unaffected by the use of fire. Neither vegetation density at the nest, nor landscape context was related to nest loss by any predator taxon. Although there were many similarities, we identified important differences in the species composing the nest predator community between our. study and other published research. These differences are likely to be responsible for geographic variation in the influence of habitat features and management actions on nest success. Our results demonstrate the need for natural resource managers to incorporate knowledge of local nest predators and their ecology when developing