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1

Bobcat Home Range Size Relative to Habitat Quality  

Microsoft Academic Search

Bobcat (Lynx rufus) home range is generally considered to be a function of habitat quality, but there have been few published studies that explicitly address this idea. We used empirically developed bobcat habitat models to predict habitat quality within bobcat home ranges on 2 study areas in central Mississippi. We then assessed the relationship between home range size and habitat

L. Mike Conner; Joseph W. Jones; Michael J. Chamberlain; Bruce D. Leopold

2001-01-01

2

Room to Live: the sizing of Lunar and Martian Habitats  

NASA Technical Reports Server (NTRS)

In order for man to return to space or extra terrestrial bodies for long duration missions it is important that adequate habitat volume be defined early to avoid costly delays and redesign. To properly define a habitat volume two major factors need to be considered. The first factor is the free or open space. This is the space that allows the crew room to move about the habitat. This space will vary based on crew size and length of the mission. The second major factor is the stowage space required for equipment and supplies. This includes both fixed volumes and consumables. Fixed volumes include items such as tools, communication equipment, Advanced Life Support (ALS) equipment, and support equipment. Consumables include items like filters, food, water and oxygen. This space is also dependent on crew size and mission length. A review of past missions into alien environments, such as deep sea habitats as well as space based habitats will be used to validate the assumption made in this paper. Once these key factors are defined trades must be run to optimize the overall volume of a habitat. This includes trades of disposable vs. reusable for items such as clothing, dishes, and water. Another factor to consider is the availability of in situ resources to aid in the construction of the habitat structure as well as re-supply of consumable items. A review of past missions into alien environments, such as deep sea habitats as well as space based habitats will be used to validate the assumption made in this paper. The result is a habitat sizing tool to provide a first order estimate of habitat volumes for extended mission to the surface of the moon and Mars.

McGregor, Walter L.

2006-01-01

3

Increases in disturbance and reductions in habitat size interact to suppress predator body size.  

PubMed

Food webs are strongly size-structured so will be vulnerable to changes in environmental factors that affect large predators. However, mechanistic understanding of environmental controls of top predator size is poorly developed. We used streams to investigate how predator body size is altered by three fundamental climate change stressors: reductions in habitat size, increases in disturbance and warmer temperatures. Using new survey data from 74 streams, we showed that habitat size and disturbance were the most important stressors influencing predator body size. A synergistic interaction between that habitat size and disturbance due to flooding meant the sizes of predatory fishes peaked in large, benign habitats and their body size decreased as habitats became either smaller or harsher. These patterns were supported by experiments indicating that habitat-size reductions and increased flood disturbance decreased both the abundance and biomass of large predators. This research indicates that interacting climate change stressors can influence predator body size, resulting in smaller predators than would be predicted from examining an environmental factor in isolation. Thus, climate-induced changes to key interacting environmental factors are likely to have synergistic impacts on predator body size which, because of their influence on the strength of biological interactions, will have far-reaching effects on food-web responses to global environmental change. PMID:24133009

Jellyman, Phillip G; McHugh, Peter A; McIntosh, Angus R

2014-05-01

4

Flower Size Variation in Rosmarinus officinalis: Individuals, Populations and Habitats  

PubMed Central

• Background and Aims Flowers are relatively invariant organs within species, but quantitative variation often exists among conspecifics. These variations represent the raw material that natural selection can magnify, eventually resulting in morphological divergence and diversification. This paper investigates floral variability in Rosmarinus officinalis, a Mediterranean shrub. • Methods Nine populations were selected in three major southern Spanish habitats (coast, lowland and mountains) along an elevation gradient. Flower samples from randomly chosen plants were collected from each population, and a total of 641 flowers from 237 shrubs were weighed while still fresh to the nearest 0·1 mg. Leaves from the same plants were also measured. Variations among habitats, sites and plants were explored with general linear model ANOVA. Leaf–flower covariation was also investigated. • Key Results Most (58 %) mass in flowers was accounted for by the corolla, whose linear dimensions correlated directly with flower mass. Averaged over plants, the mass of a flower varied between 12 mg and 38 mg. Habitat, site (within habitat) and shrub identity had significant effects on mass variance. Flowers from the coast were the smallest (17 mg) and those from the mountains the largest (25 mg on average). A pattern of continuously increasing flower size with elevation emerged which was largely uncoupled from the geographical pattern of leaf size variation. • Conclusions As regards flower size, a great potential to local differentiation exists in Rosmarinus. Observed divergences accord with a regime of large-bodied pollinator selection in the mountains, but also with resource–cost hypotheses on floral evolution that postulate that reduced corollas are advantageous under prevailingly stressful conditions. PMID:15585545

HERRERA, JAVIER

2004-01-01

5

Effects of habitat quality and size on extinction in experimental populations  

PubMed Central

Stochastic population theory makes clear predictions about the effects of reproductive potential and carrying capacity on characteristic time-scales of extinction. At the same time, the effects of habitat size and quality on reproduction and regulation have been hotly debated. To trace the causal relationships among these factors, we looked at the effects of habitat size and quality on extinction time in experimental populations of Daphnia magna. Replicate model systems representative of a broad-spectrum consumer foraging on a continuously supplied resource were established under crossed treatments of habitat size (two levels) and habitat quality (three levels) and monitored until eventual extinction of all populations. Using statistically derived estimates of key parameters, we related experimental treatments to persistence time through their effect on carrying capacity and the population growth rate. We found that carrying capacity and the intrinsic rate of increase were each influenced similarly by habitat size and quality, and that carrying capacity and the intrinsic rate of increase were in turn both correlated with time to population extinction. We expected habitat quality to have a greater influence on extinction. However, owing to an unexpected effect of habitat size on reproductive potential, habitat size and quality were similarly important for population persistence. These results support the idea that improving the population growth rate or carrying capacity will reduce extinction risk and demonstrate that both are possible by improving habitat quality or increasing habitat size. PMID:18544509

Griffen, Blaine D; Drake, John M

2008-01-01

6

Invertebrate community structure along a habitat-patch size gradient within a bog pool complex   

E-print Network

This thesis characterises species richness and community structure over a habitat-patch size gradient of a typical bog-pool complex, investigating the effect of pool size on aquatic invertebrate communities. In this study, twenty-two pools were...

Towers, Naomi M.

7

Determination of auditory thresholds in the brushtail possum (Trichosurus vulpecula).  

PubMed

The auditory abilities of the brushtail possum (Trichosurus vulpecula) have been measured by cochlear potential readings, but no behavioural determinations of their auditory abilities have been published. Six experimentally naive possums were trained to perform a two-response conditional discrimination between the presence and absence of an 880-Hz tone (at 80 dB). All six possums readily learned this task. The behavioural threshold for this tone was determined using a modified tracking procedure and found to be similar to that reported using cochlear microphonic potentials. One concern with the current method was the communal nature of the experimental environment so a further threshold determination in a sound-attenuating chamber was conducted. No substantial difference was noted between the results obtained in the two threshold determinations. The success of the current method means that a full, behavioural audiogram for the brushtail possum, which would complement the existing cochlear potential data, is now possible. PMID:11399311

Signal, T; Foster, T M; Temple, W

2001-05-01

8

Effects of habitat complexity and group size on perceived predation risk in goldfish (Carassius auratus)  

Microsoft Academic Search

Habitat structural complexity can be an important factor in animal decisions such as habitat choice, patch use, and even mate choice. We investigate how the structural complexity of cover and group size affect perceived predation risk in goldfish (Carassius auratus) by measuring behaviors indicative of vigilance. Goldfish were videotaped in an aquarium while foraging on a saturated food patch near

J. Ingrum; S. E. Nordell; J. Dole

2010-01-01

9

VARIATION IN JUVENILE COHO SALMON END-OF-SUMMER SIZE: HIERARACHICAL ANALYSIS OF HABITAT EFFECTS  

EPA Science Inventory

The size of coho salmon juveniles entering the winter has been shown to influence overwinter survival, and hence may be a useful indicator of linkages between summer habitat conditions and subsequent smolt production. We are investigating habitat-specific demographics of juvenile...

10

Effects of Group-Selection Opening Size on Breeding Bird Habitat Use in a Bottomland Forest  

Microsoft Academic Search

An increase in timber removals from southern bottomland forests of the United States has been predicted, warranting investigations of the effects of silvicultural alternatives on avian breeding habitat. We studied the effects of creating group-selection openings (man-made canopy gaps) of various sizes on breeding bird habitat use in a bot- tomland hardwood forest in the Upper Coastal Plain of South

Christopher E. Moorman; David C. Guynn Jr.

2001-01-01

11

Cardiovascular responses to exercise in the brush-tailed possum  

Microsoft Academic Search

1.Levels of oxygen consumption (\\u000a$$\\\\dot V_{O_2 } $$\\u000a), heart rate (fH) and arterio-venous oxygen differences (a-v)-CO2 were measured during locomotion in the Brushtailed possum,Trichosurus vulpecula.2.\\u000a$$\\\\dot V_{O_2 } $$\\u000a showed a linear increase with running speed (Fig. 1) but a plateau was evident infH at higher speeds (Fig. 2). Values of (a-v)CO2 showed an hyperbolic increase with running

R. V. Baudinette; R. S. Seymour; J. Orbach

1978-01-01

12

Complex size-dependent habitat associations in potamodromous fish species  

Microsoft Academic Search

Knowledge of the distribution of species life stages at multiple spatial scales is fundamental to both a proper assessment\\u000a of species management and conservation programmes and the ability to predict the consequences of human disturbances for river\\u000a systems. The habitat requirements of three native cyprinid species—the Iberian barbel Barbus bocagei Steindachner, the Iberian straight-mouth nase Pseudochondrostoma polylepis (Steindachner), and the

José Maria Santos; Luís Reino; Miguel Porto; João Oliveira; Paulo Pinheiro; Pedro Raposo Almeida; Rui Cortes; Maria Teresa Ferreira

2011-01-01

13

Habitat-specific clutch size and cost of incubation in eiders reconsidered.  

PubMed

The energetic incubation constraint hypothesis (EICH) for clutch size states that birds breeding in poor habitat may free up resources for future reproduction by laying a smaller clutch. The eider (Somateria mollissima) is considered a candidate for supporting this hypothesis. Clutch size is smaller in exposed nests, presumably because of faster heat loss and higher incubation cost, and, hence, smaller optimal clutch size. However, an alternative explanation is partial predation: the first egg(s) are left unattended and vulnerable to predation, which may disproportionately affect exposed nests, so clutch size may be underestimated. We experimentally investigated whether predation on first-laid eggs in eiders depends on nest cover. We then re-evaluated how nesting habitat affects clutch size and incubation costs based on long-term data, accounting for confounding effects between habitat and individual quality. We also experimentally assessed adult survival costs of nesting in sheltered nests. The risk of egg predation in experimental nests decreased with cover. Confounding between individual and habitat quality is unlikely, as clutch size was also smaller in open nests within individuals, and early and late breeders had similar nest cover characteristics. A trade-off between clutch and female safety may explain nest cover variation, as the risk of female capture by us, mimicking predation on adults, increased with nest cover. Nest habitat had no effect on female hatching weight or weight loss, while lower temperature during incubation had an unanticipated positive relationship with hatching weight. There were no indications of elevated costs of incubating larger clutches, while clutch size and colony size were positively correlated, a pattern not predicted by the 'energetic incubation constraint' hypothesis. Differential partial clutch predation thus offers the more parsimonious explanation for clutch size variation among habitats in eiders, highlighting the need for caution when analysing fecundity and associated life-history parameters when habitat-specific rates of clutch predation occur. PMID:18795336

Ost, Markus; Wickman, Mikael; Matulionis, Edward; Steele, Benjamin

2008-11-01

14

Habitat  

NSDL National Science Digital Library

This video segment from IdahoPTV's D4K explains the 4 basic requirements of a perfect habitat and what a niche is within a habitat. You'll see videos of different animals in their habitats, such as; bear, moose, spiders and mountain goats,

Idaho PTV

2011-09-21

15

HOME RANGE SIZE, MOVEMENT AND HABITAT USE FOR A POPULATION OF BLANDING'S TURTLES (EMYS BLANDINGII) IN THE UPPER MISSISSIPPI  

E-print Network

HOME RANGE SIZE, MOVEMENT AND HABITAT USE FOR A POPULATION OF BLANDING'S TURTLES (EMYS BLANDINGII TABLE OF CONTENTS LIST OF FIGURES iii LIST OF TABLES iv HOME RANGE SIZE, MOVEMENT AND HABITAT USE. HOME RANGE AND HABITAT COMPOSITION MAPS FOR ALL 17 RADIO-TRACKED TURTLES IN THE UPPER MISSISSIPPI RIVER

Janzen, Fredric

16

Home-range Size and Habitat Used by the Northern Myotis (Myotis septentrionalis)  

USGS Publications Warehouse

We examined home range size and habitat use of nine female northern myotis (Myotis septentrionalis) within an intensively managed forest in the central Appalachians of West Virginia. Using the 95% adaptive kernel method, we calculated a mean home range of 65 ha. Northern myotis used recent diameter-limit harvests and road corridors more than expected based on availability of these habitats. Intact forest stands and more open deferment harvested stands were used less than expected based on the availability of these habitats, although intact forest stands still constituted the overall majority of habitat used. Partial timber harvests that leave a relatively closed canopy appear to promote or improve northern myotis foraging habitat in heavily forested landscapes. However, the long-term ecological impacts on bats and other biota from this silviculturally unacceptable practice are unclear.

Owen, S.F.; Menzel, M.A.; Ford, W.M.; Chapman, B.R.; Miller, K.V.; Edwards, J.W.; Wood, P.B.

2003-01-01

17

Habitat area and climate stability determine geographical variation in plant species range sizes.  

PubMed

Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ~ 85 000 plant species across the New World. We assess prominent hypothesised range-size controls, finding that plant range sizes are codetermined by habitat area and long- and short-term climate stability. Strong short- and long-term climate instability in large parts of North America, including past glaciations, are associated with broad-ranged species. In contrast, small habitat areas and a stable climate characterise areas with high concentrations of small-ranged species in the Andes, Central America and the Brazilian Atlantic Rainforest region. The joint roles of area and climate stability strengthen concerns over the potential effects of future climate change and habitat loss on biodiversity. PMID:24119177

Morueta-Holme, Naia; Enquist, Brian J; McGill, Brian J; Boyle, Brad; Jørgensen, Peter M; Ott, Jeffrey E; Peet, Robert K; Símová, Irena; Sloat, Lindsey L; Thiers, Barbara; Violle, Cyrille; Wiser, Susan K; Dolins, Steven; Donoghue, John C; Kraft, Nathan J B; Regetz, Jim; Schildhauer, Mark; Spencer, Nick; Svenning, Jens-Christian

2013-12-01

18

Effects of Plot Size and Habitat Characteristics on Breeding Success of Scarlet Tanagers  

Microsoft Academic Search

We studied the effects of forest patch size and habitat characteristics on breeding success of Scarlet Tanagers (Piranga olivacea) in western New York in 1995 and 1996. Twenty forest stands were grouped into four size classes: Group I (<10>ha, n = 6), Group 11 (10 to 50 ha, n = 7), Group III (>50 to 150 ha, n = 5),

Christopher Roberts; Christopher J. Norment

1999-01-01

19

CHANGES IN HABITAT USE AND MOVEMENT PATTERNS WITH BODY SIZE IN BLACK RATSNAKES (ELAPHE OBSOLETA)  

E-print Network

; Juvenile; Snake; Ontogeny BODY SIZE is one of the most influential aspects of an animal's phenotype fromCHANGES IN HABITAT USE AND MOVEMENT PATTERNS WITH BODY SIZE IN BLACK RATSNAKES (ELAPHE OBSOLETA, University of Ottawa, 30 Marie-Curie, Ottawa, Ontario K1N 6N5, Canada 2 Program in Ecology, Evolution

Blouin-Demers, Gabriel

20

Habitat degradation and fishing effects on the size structure of coral reef fish communities.  

PubMed

Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island-scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine-scale architectural complexity eroded due to coral bleaching and outbreaks of crown-of-thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large-bodied fish and/or more small-bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (approximately 12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish < 20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large-bodied target species, while habitat loss results in fewer small-bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat. PMID:20405798

Wilson, S K; Fisher, R; Pratchett, M S; Graham, N A J; Dulvy, N K; Turner, R A; Cakacaka, A; Polunin, N V C

2010-03-01

21

Conjunctival vaccination of the brushtail possum (Trichosurus vulpecula) with bacille Calmette-Guérin  

Microsoft Academic Search

AIM: To determine the efficacy of conjunctival vaccination of captive brushtail possums (Trichosurus vulpecula) with bacille Calmette-Guérin (BCG), as measured by immunological responses to vaccination and response to intratracheal challenge with Mycobacterium bovis.METHODS: Nine adult male brushtail possums were vaccinated by the instillation of a suspension of BCG strain Pasteur 1173P2 into the conjunctival sac of each eye. Each drop

LAL Corner; BM Buddle

2005-01-01

22

Fish size and habitat depth relationships in headwater streams  

Microsoft Academic Search

Surveys of 262 pools in 3 small streams in eastern Tennessee demonstrated a strong positive relationship between pool depth and the size of the largest fish within a pool (PCampostoma anomalum); one used creek chubs (Semotilus atromaculatus); and one used striped shiners (Notropis chrysocephalus). The stoneroller experiments showed that survival of fish approximately 100 mm in total length (TL) was

B. C. Harvey; A. J. Stewart

1991-01-01

23

TERRITORY SIZE IN MEGACERYLE ALCYON ALONG A STREAM HABITAT  

Microsoft Academic Search

tions between territory size and various envi- ronmental parameters. Most frequently, re- source density (Pitelka et al. 1955, Stenger 1958, Gill and Wolf 1975, Salomonson and Bal- da 1977) and\\/or population density (Myers et al. 1979, 1980; Ewald et al. 1980) are cited, but, as is now becoming evident, the proximate causal mechanisms responsible for these cor- relations are not

WILLIAM JAMES DAVIS

24

Inter-habitat variation in density and size composition of reef fishes from the Cuban Northwestern shelf.  

PubMed

Movement and exchange of individuals among habitats is critical for the dynamics and success of reef fish populations. Size segregation among habitats could be taken as evidence for habitat connectivity, and this would be a first step to formulate hypotheses about ontogenetic inter-habitat migrations. The primary goal of our research was to find evidence of inter-habitat differences in size distributions and density of reef fish species that can be classified a priori as habitat-shifters in an extensive (-600km2) Caribbean shelf area in NW Cuba. We sampled the fish assemblage of selected species using visual census (stationary and transect methods) in 20 stations (sites) located in mangrove roots, patch reefs, inner zone of the crest and fore reef (12-16m depth). In each site, we performed ten censuses for every habitat type in June and September 2009. A total of 11 507 individuals of 34 species were counted in a total of 400 censuses. We found significant differences in densities and size compositions among reef and mangrove habitats, supporting the species-specific use of coastal habitats. Adults were found in all habitats. Reef habitats, mainly patch reefs, seem to be most important for juvenile fish of most species. Mangroves were especially important for two species of snappers (Lutjanus apodus and L. griseus), providing habitat for juveniles. These species also displayed well defined gradients in length composition across the shelf. PMID:25102642

Aguilar, Consuelo; González-Sansón, Gaspar; Cabrera, Yureidy; Ruiz, Alexei; Curry, R Allen

2014-06-01

25

How big and how close? Habitat patch size and spacing to conserve a threatened species  

EPA Science Inventory

We present results of a spatially-explicit, individual-based stochastic dispersal model (HexSim) to evaluate effects of size and spacing of patches of habitat of Northern Spotted Owls (NSO; Strix occidentalis caurina) in Pacific Northwest, USA, to help advise USDI Fish and Wildli...

26

SCIENCE VOL 292 25 MAY 2001 Coral Reef Biodiversity--Habitat Size Matters  

E-print Network

SCIENCE VOL 292 25 MAY 2001 ECOLOGY: Coral Reef Biodiversity--Habitat Size Matters Nancy Knowlton* Coral reefs are the most diverse of all marine ecosystems (1), with estimates of reef species ranging-Australian archipelago. For example, reefs in the central Indo-Pacific have more than 10 times as many coral and fish

Bermingham, Eldredge

27

Herbivore impact on grassland plant diversity depends on habitat productivity and herbivore size  

E-print Network

LETTER Herbivore impact on grassland plant diversity depends on habitat productivity and herbivore *Correspondence: E-mail: l.bakker@nioo.knaw.nl Abstract Mammalian herbivores can have pronounced effects on plant and herbivores of different body size on plant species richness across a 10-fold productivity gradient using a 7

Minnesota, University of

28

DIATOM SPECIES RICHNESS IN STREAMS OF THE EASTERN US: STREAM SIZE AND HABITAT EFFECTS  

EPA Science Inventory

We analyzed the relationship between benthic diatom assemblages, stream size, and habitat characteristics in 445 first through seventh order streams in the Mid-Atlantic (n=230), South Atlantic (n=61), Ohio (n=140), and Tennessee (n=14) hydrologic regions. Diatom samples were col...

29

Comparing Size, Movement, and Habitat Selection of Wild and Streamside-Reared Lake Sturgeon  

Microsoft Academic Search

A streamside rearing facility (SRF) on the Big Manistee River, Michigan, was constructed for the purpose of rearing larval and age-0 lake sturgeon Acipenser fulvescens. Size, movement, and habitat selection were studied from 2007 to 2008 to determine whether there were differences between age-0 lake sturgeon reared in the streamside facility and natural cohorts. Lake sturgeon reared streamside showed no

Kevin A. Mann; J. Marty Holtgren; Nancy A. Auer; Stephanie A. Ogren

2011-01-01

30

Mind the gap: genetic distance increases with habitat gap size in Florida scrub jays.  

PubMed

Habitat gap size has been negatively linked to movement probability in several species occupying fragmented landscapes. How these effects on movement behaviour in turn affect the genetic structure of fragmented populations at local scales is less well known. We tested, and confirmed, the hypothesis that genetic differentiation among adjacent populations of Florida scrub jays--an endangered bird species with poor dispersal abilities and a high degree of habitat specialization--increases with the width of habitat gaps separating them. This relationship was not an artefact of simple isolation-by-distance, as genetic distance was not correlated with the Euclidean distance between geographical centroids of the adjacent populations. Our results suggest that gap size affects movement behaviour even at remarkably local spatial scales, producing direct consequences on the genetic structure of fragmented populations. This finding shows that conserving genetic continuity for specialist species within fragmented habitat requires maintenance or restoration of preserve networks in which habitat gaps do not exceed a species-specific threshold distance. PMID:22357936

Coulon, Aurélie; Fitzpatrick, John W; Bowman, Reed; Lovette, Irby J

2012-08-23

31

Habitat-specific clutch size and cost of incubation in eiders reconsidered  

Microsoft Academic Search

The energetic incubation constraint hypothesis (EICH) for clutch size states that birds breeding in poor habitat may free\\u000a up resources for future reproduction by laying a smaller clutch. The eider (Somateria mollissima) is considered a candidate for supporting this hypothesis. Clutch size is smaller in exposed nests, presumably because of\\u000a faster heat loss and higher incubation cost, and, hence, smaller

Markus Öst; Mikael Wickman; Edward Matulionis; Benjamin Steele

2008-01-01

32

Habitat selection by breeding waterbirds at ponds with size-structured fish populations  

NASA Astrophysics Data System (ADS)

Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size structure of common carp ( Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural system of monocultured ponds, where three fish age classes were separately stocked. Fish age corresponded to a distinct fish size gradient. Fish age and total biomass, macroinvertebrate and amphibian abundance, and emergent vegetation best explained the differences in bird density between ponds. Abundance of animal prey other than fish (aquatic macroinvertebrates and larval amphibians) decreased with increasing carp age in the ponds. Densities of ducks and smaller grebes were strongly negatively associated with fish age/size gradient. The largest of the grebes, the piscivorous great crested grebe ( Podiceps cristatus), was the only species that preferred ponds with medium-sized fish and was positively associated with total fish biomass. Habitat selection by bitterns and most rallids was instead strongly influenced by the relative amount of emergent vegetation cover in the ponds. Our results show that fish size structure may be an important cue for breeding habitat choice and a factor affording an opportunity for niche diversification in avian communities.

Kloskowski, Janusz; Nieoczym, Marek; Polak, Marcin; Pitucha, Piotr

2010-07-01

33

Patterns in estuarine macrofauna body size distributions: The role of habitat and disturbance impact  

NASA Astrophysics Data System (ADS)

Schwinghamer's (1981) habitat architecture hypothesis for body mass spectra in marine sediments predicts a single macrofauna mode in response to the bulk nature of the sediment. This proposition was examined for intertidal macrofauna from a well-studied estuarine system, using kernel density estimation to define modality and the locations of peaks and troughs. Three sedimentary environments and habitats were examined along a disturbance gradient related to eutrophication. Our results indicate that bimodality is likely to occur within the macrofauna size range, which weakens the habitat architecture model and casts doubts on the mechanisms behind other modes in benthic size spectra. The location of the modes and intervening trough were not conservative and not apparently related to sediment grain size or habitat structure, but somewhat dependent on the presence of particular species: the presence or absence of large numbers of individuals of Hydrobia ulvae and larger-bodied taxa such as Scrobicularia plana and Hediste diversicolor. Alternative competing hypotheses are explored for the observed results, including Warwick's (1984) phylogenetic explanation, but taking into consideration both species composition and disturbance impact, it seems most likely Holling's (1992) textural discontinuity hypothesis, as a measure of resilience, could be a plausible explanation.

Dolbeth, Marina; Raffaelli, Dave; Pardal, Miguel Ângelo

2014-01-01

34

Distribution and size of benthic marine habitats in Dominica, Lesser Antilles.  

PubMed

Surveys of benthic marine habitats encompassing 1814.7 ha and lining 90% of Dominica's shoreline were carried out to build the first composite picture of the distribution and size of the island's near-shore sublittoral habitats, and the epibenthic communities they harbor. Field survey sites covered areas ranging from 1425 to 29.6 ha, lining the shore in bands ranging between 50 and 250 m in width, in waters no deeper than 30 m. Thus a total of 755 ha of benthos were surveyed in October and November of 2007. The benthic habitat composition of an additional 1059.7 ha was inferred with the help of unpublished data and satellite imagery. Seagrass beds were the most widespread organism-built habitat type with 265 ha. Coral reefs covered 72.2 ha. Both of these habitats were predominantly established along the West and North coasts, which included the island's most habitat-diverse regions. Rocky environments (911.5 ha) dominated the East and South coast and together with sandy areas (566 ha) constituted 81% of the island's marine benthos. It is apparent that seagrass beds, which include four native and one invasive seagrass species, had not been surveyed as previous distribution reports could not be confirmed. Similarly, the benthic cover of Dominica's coral reefs is evidently far below the previously reported 7000 ha. Such discrepancies highlight the advantage of environmental assessments based on field surveys and systematic data compilation, particularly in cases like Dominica where a narrow island shelf stages marginal marine resources in spatial proximity to each other and human settlements. This study has demonstrated how low-tech field methods can be applied on an island-wide scale to build an inventory of marine resources in the form of habitat maps and data repositories publicly accessible for future use. In the absence of such efforts, the development of conservation measures and status reports will remain ill founded. PMID:20527461

Steiner, Sascha Claus Christoff; Willette, Demian Alexander

2010-06-01

35

Sexual size dimorphism in anurans: roles of mating system and habitat types  

PubMed Central

Background Sexual size dimorphism (SSD) is widespread and variable among animals. Sexual selection, fecundity selection and ecological divergence between males and females are the major evolutionary forces of SSD. However, the influences of mating system and habitat types on SSD have received little attention. Here, using phylogenetic comparative methods, we at first examine the hypotheses to that mating system (intensity of sexual selection) and habitat types affect significantly variation in SSD in anurans (39 species and 18 genera). Results Our data set encompass 39 species with female-biased SSD. We provide evidence that the effects of mating system and habitat types on SSD were non-significant across species, also when the analyses were phylogenetically corrected. Conclusions Contrast to the hypotheses, our findings suggest that mating system and habitat types do not play an important role in shaping macro-evolutionary patterns of SSD in anurans. Mating system and habitat types cannot explain the variation in SSD when correcting for phylogenetic effects. PMID:24199676

2013-01-01

36

Landscape selection by piping plovers has implications for measuring habitat and population size  

USGS Publications Warehouse

How breeding birds distribute in relation to landscape-scale habitat features has important implications for conservation because those features may constrain habitat suitability. Furthermore, knowledge of these associations can help build models to improve area-wide demographic estimates or to develop a sampling stratification for research and monitoring. This is particularly important for rare species that have uneven distributions across vast areas, such as the federally listed piping plover (Charadrius melodus; hereafter plover). We examined how remotely-sensed landscape features influenced the distribution of breeding plover pairs among 2-km shoreline segments during 2006–2009 at Lake Sakakawea in North Dakota, USA. We found strong associations between remotely-sensed landscape features and plover abundance and distribution (R2 = 0.65). Plovers were nearly absent from segments with bluffs (>25 m elevation increase within 250 m of shoreline). Relative plover density (pairs/ha) was markedly greater on islands (4.84 ± 1.22 SE) than on mainlands (0.85 ± 0.17 SE). Pair numbers increased with abundance of nesting habitat (unvegetated-flat areas ?^=0.28±0.08SE ). On islands, pair numbers also increased with the relative proportion of the total area that was habitat ( ?^=3.27±0.46SE ). Our model could be adapted to estimate the breeding population of plovers or to make predictions that provide a basis for stratification and design of future surveys. Knowledge of landscape features, such as bluffs, that exclude use by birds refines habitat suitability and facilitates more accurate estimates of habitat and population abundance, by decreasing the size of the sampling universe. Furthermore, techniques demonstrated here are applicable to other vast areas where birds breed in sparse or uneven densities.

Anteau, Michael J.; Shaffer, Terry L.; Wiltermuth, Mark T.; Sherfy, Mark H.

2014-01-01

37

Trophic levels colonize sequentially but effects of habitat size and quality are transient  

NASA Astrophysics Data System (ADS)

Ecologists study assembling communities to understand mechanisms responsible for community-level patterns such as trophic structure. As communities assemble the incidence of each trophic level is conditional upon available resources such as prey, habitat area and productivity. Larger, more productive habitats may have more resources, increasing the potential to attract and to support greater species diversity, abundance, and more trophic levels. Predator trophic breadth and prey incidence may influence colonization order because obligate specialists have stricter prey dependencies than generalists do. In a system of stacked specialists, colonization may occur sequentially by trophic level because prey must be present before the next higher trophic level can colonize. Sequential colonization ordered by trophic level and by trophic breadth were tested with a field experiment and a Monte Carlo simulation. Community assembly was observed for an aphid food-web module composed of nine specialist and generalist predators colonizing plots seeded with California native annuals. To test the importance of habitat quality and resources, plots were manipulated for size (1 m2 and 10 m2) and productivity (+/0 fertilizer), and then sampled for colonists many times during the growing season of 2003. Specialists from higher trophic levels were observed to colonize after their prey had arrived in the field experiment only, providing field support for the hypothesis of sequential colonization ordered by trophic level during community assembly. Intriguingly, generalist predators colonized later than specialists, despite the high and early availability of aphid prey. This finding contradicts the assumption that a narrow trophic breadth may disadvantage specialist colonizers. Initially, predator and prey densities increased on fertilized plots, but later this pattern was observed only on small plots. Patterns of sequential colonization order by trophic level and trophic breadth were demonstrated during community assembly, but the transient responses of colonizers to habitat size and productivity suggests that habitat resource effects deserve further study to determine their effects on trophic structure during community assembly.

Piechnik, Denise A.

2013-02-01

38

Movement Patterns, Habitat Utilization, Home Range Size and Site Fidelity of Whitesaddle Goatfish, Parupeneus Porphyreus, In a Marine Reserve  

Microsoft Academic Search

Suitability of small (2) marine reserves for protecting a commercially important endemic Hawaiian goatfish, Parupeneus porphyreus, was examined by quantifying goatfish habitat use, home range size and site fidelity in an existing marine reserve (Coconut Island in Kaneohe Bay, Hawaii). Five goatfish equipped with acoustic transmitters were tracked for up to 93?h each over 3–14 days. Daytime habitat use patterns

Carl G. Meyer; Kim N. Holland; Bradley M. Wetherbee; Christopher G. Lowe

2000-01-01

39

Size-and depth-dependent variation in habitat and diet of the common carp (Cyprinus carpio)  

E-print Network

Size- and depth-dependent variation in habitat and diet of the common carp (Cyprinus carpio) Emili, Cyprinus carpio, diet, Lake Banyoles, Spain. ABSTRACT The habitat and diet variation of the common carp (Cyprinus carpio) were studied in Lake Banyo- les (Catalonia, Spain). Carp was the second most abundant

García-Berthou, Emili

40

VARIATION IN JUVENILE COHO SALMON END-OF-SUMMER SIZE AND ABUNDANCE: HIERARCHICAL ANALYSIS OF HABITAT EFFECTS  

EPA Science Inventory

The size of coho salmon juveniles entering the winter has been shown to influence overwinter survival, and hence may be a useful indicator of linkages between summer habitat conditions and subsequent smolt production. We are investigating habitat-specific demographics of juvenile...

41

Dispersal sinks and handling effects: interpreting the role of immigration in common brushtail possum populations  

Microsoft Academic Search

Summary 1. An evaluation of the potentially adverse effects of measurement must be made before concluding that one is dealing with a 'dispersal sink'. 2. We conducted a spatially and temporally replicated removal experiment on common brushtail possums ( Trichosurus vulpecula ) in uniformly suitable old-growth eucalypt forest in south-eastern Australia, that was designed to address the question: does immi-

Michael Clinchy; Charles J. Krebs; Peter J. Jarman

2001-01-01

42

Tawny frogmouths and brushtail possums as sentinels for Angiostrongylus cantonensis, the rat lungworm.  

PubMed

The objective of this study was to determine the prevalence of angiostrongylosis in tawny frogmouths (Podargus strigoides) and brushtail possums (Trichosurus vulpecula) with signs of neurological disease, and to describe the clinicopathological features of angiostrongylosis in both species. Tawny frogmouths and brushtail possums with signs of neurological disease were sampled from the Sydney metropolitan area between October 1998 and June 2010. Samples from 100 tawny frogmouths and 31 brushtail possums from the Australian Registry of Wildlife Health (ARWH), the Wildlife Assistance and Information Foundation (WAIF) and Wildlife Health and Conservation Centre (WHCC), University of Sydney were examined. Histological examinations of the brain, spinal cord and other available tissues were used to characterize the disease responsible for each animal's clinical signs. Of the 100 tawny frogmouths with neurological disease examined, angiostrongylosis was considered responsible in 80 (80%), traumatic injury in 17 (17%), protozoal infection in 3 (3%) and other diseases in 2 (2%) and the cause of clinical signs was unknown in 10 (10%). Eleven tawny frogmouths presenting with neurological signs associated with head trauma had concurrent angiostrongylosis. Of the 31 brushtail possums, Wobbly Possum Syndrome (WPS) was diagnosed in 21 (68%), angiostrongylosis in 4 (13%) and other diseases in the remaining 6 (19%). Angiostrongylosis was overrepresented in hand reared juvenile possums. Cases of angiostrongylosis in tawny frogmouths followed a strong seasonal pattern peaking through late summer and autumn. The results confirm that Angiostrongylus cantonensis is endemic in Sydney, Australia and that tawny frogmouths could be important sentinels for this zoonotic parasite. PMID:23218219

Ma, Gemma; Dennis, Michelle; Rose, Karrie; Spratt, David; Spielman, Derek

2013-02-18

43

Preferred habitat and effective population size drive landscape genetic patterns in an endangered species.  

PubMed

Landscape genetics provides a framework for pinpointing environmental features that determine the important exchange of migrants among populations. These studies usually test the significance of environmental variables on gene flow, yet ignore one fundamental driver of genetic variation in small populations, effective population size, N(e). W(e) combined both approaches in evaluating genetic connectivity of a threatened ungulate, woodland caribou. We used least-cost paths to calculate matrices of resistance distance for landscape variables (preferred habitat, anthropogenic features and predation risk) and population-pairwise harmonic means of N(e), and correlated them with genetic distances, FST and D(c). Results showed that spatial configuration of preferred habitat and Ne were the two best predictors of genetic relationships. Additionally, controlling for the effect of Ne increased the strength of correlations of environmental variables with genetic distance, highlighting the significant underlying effect of Ne in modulating genetic drift and perceived spatial connectivity. We therefore have provided empirical support to emphasize preventing increased habitat loss and promoting population growth to ensure metapopulation viability. PMID:24004939

Weckworth, Byron V; Musiani, Marco; Decesare, Nicholas J; McDevitt, Allan D; Hebblewhite, Mark; Mariani, Stefano

2013-10-22

44

Preferred habitat and effective population size drive landscape genetic patterns in an endangered species  

PubMed Central

Landscape genetics provides a framework for pinpointing environmental features that determine the important exchange of migrants among populations. These studies usually test the significance of environmental variables on gene flow, yet ignore one fundamental driver of genetic variation in small populations, effective population size, Ne. We combined both approaches in evaluating genetic connectivity of a threatened ungulate, woodland caribou. We used least-cost paths to calculate matrices of resistance distance for landscape variables (preferred habitat, anthropogenic features and predation risk) and population-pairwise harmonic means of Ne, and correlated them with genetic distances, FST and Dc. Results showed that spatial configuration of preferred habitat and Ne were the two best predictors of genetic relationships. Additionally, controlling for the effect of Ne increased the strength of correlations of environmental variables with genetic distance, highlighting the significant underlying effect of Ne in modulating genetic drift and perceived spatial connectivity. We therefore have provided empirical support to emphasize preventing increased habitat loss and promoting population growth to ensure metapopulation viability. PMID:24004939

Weckworth, Byron V.; Musiani, Marco; DeCesare, Nicholas J.; McDevitt, Allan D.; Hebblewhite, Mark; Mariani, Stefano

2013-01-01

45

Movements, home-range size and habitat selection of mallards during autumn migration.  

PubMed

The mallard (Anas platyrhynchos) is a focal species in game management, epidemiology and ornithology, but comparably little research has focused on the ecology of the migration seasons. We studied habitat use, time-budgets, home-range sizes, habitat selection, and movements based on spatial data collected with GPS devices attached to wild mallards trapped at an autumn stopover site in the Northwest European flyway. Sixteen individuals (13 males, 3 females) were followed for 15-38 days in October to December 2010. Forty-nine percent (SD?=?8.4%) of the ducks' total time, and 85% of the day-time (SD?=?28.3%), was spent at sheltered reefs and bays on the coast. Two ducks used ponds, rather than coast, as day-roosts instead. Mallards spent most of the night (76% of total time, SD?=?15.8%) on wetlands, mainly on alvar steppe, or in various flooded areas (e.g. coastal meadows). Crop fields with maize were also selectively utilized. Movements between roosting and foraging areas mainly took place at dawn and dusk, and the home-ranges observed in our study are among the largest ever documented for mallards (mean ?=?6,859 ha; SD?=?5,872 ha). This study provides insights into relatively unknown aspects of mallard ecology. The fact that autumn-staging migratory mallards have a well-developed diel activity pattern tightly linked to the use of specific habitats has implications for wetland management, hunting and conservation, as well as for the epidemiology of diseases shared between wildlife and domestic animals. PMID:24971887

Bengtsson, Daniel; Avril, Alexis; Gunnarsson, Gunnar; Elmberg, Johan; Söderquist, Pär; Norevik, Gabriel; Tolf, Conny; Safi, Kamran; Fiedler, Wolfgang; Wikelski, Martin; Olsen, Björn; Waldenström, Jonas

2014-01-01

46

Quality of coastal and estuarine essential fish habitats: estimations based on the size of juvenile common sole ( Solea solea L.)  

NASA Astrophysics Data System (ADS)

Survival and growth of early fish stages are maximal in coastal and estuarine habitats where natural shallow areas serve as nurseries for a variety of widely distributed species on the continental shelf. Processes occurring in these nursery grounds during the juvenile stage affect growth and may be important in regulating the year-class strength of fishes and population size. The need, therefore, exists to protect these essential fish habitats hence to develop indicators to estimate their quality. The purpose of the present study was to use the growth of juvenile sole as a means of comparing the quality of coastal and estuarine nursery habitats in the Bay of Biscay (France). These sole nurseries were clearly identified from studies based on trawl surveys carried out during the last two decades. The size of 1-group juveniles at the end of their second summer, as estimated from these surveys, is an indicator of growth in these habitats during the juvenile phase and can be used to compare habitat quality. A model taking into account the role of seawater temperature in spatial and interannual variations of juvenile size was developed to compare growth performance in the different nursery sectors. This study shows that the size of juvenile sole after two summers of life is not density-dependent, probably because the size of the population adapts to habitat capacity after high mortality during early-juvenile stages. Size is on one hand positively related to temperature and on the other hand higher in estuarine than in non-estuarine habitats. This high growth potential of juvenile fish in estuarine areas confirms the very important role played by estuaries as nursery grounds and the essential ecological interest of these limited areas in spite of their low water quality. If a general conclusion on habitat quality is to be reached about studies based on the growth of juvenile fish, it is necessary to use not only an integrative indicator of growth, like size, representative of the intrinsic habitat quality, but also more sensitive and less integrative means, such as otolith increments or caging experiments, which better respond to anthropogenic disturbance. Moreover, it is necessary to take juvenile densities into account.

Le Pape, O.; Holley, J.; Guérault, D.; Désaunay, Y.

2003-12-01

47

Habitat association, size, stomach contents, and reproductive condition of Puerto Rican boas (Epicrates inornatus)  

USGS Publications Warehouse

The Puerto Rican boa occurs in a variety of habitats, including wet montane forest, lowland wet forest, mangrove forest, wet limestone karst, and offshore cays, and from sea level to 480 m. Mean SVL of 49 encountered boas (live and road-killed) was 136.9 ?? 35.1 (range = 38.8-205 cm), with a mean mass of 952.1 ?? 349.0 g (n = 47; range = 140-1662 g). Prey in digestive tracts (n = 29) included remains of black rats, house mice, three species of anoles, bats, common ground-doves, domestic fowl chicks, and invertebrates. Females were in reproductive condition in late April through mid-August and had an average brood size of 21.8 ?? 6.0 (n = 9, range = 13-30 ).

Wiley, J.W.

2003-01-01

48

Effects of Spatial Subsidies and Habitat Structure on the Foraging Ecology and Size of Geckos  

PubMed Central

While it is well established that ecosystem subsidies—the addition of energy, nutrients, or materials across ecosystem boundaries—can affect consumer abundance, there is less information available on how subsidy levels may affect consumer diet, body condition, trophic position, and resource partitioning among consumer species. There is also little information on whether changes in vegetation structure commonly associated with spatial variation in subsidies may play an important role in driving consumer responses to subsidies. To address these knowledge gaps, we studied changes in abundance, diet, trophic position, size, and body condition of two congeneric gecko species (Lepidodactylus spp.) that coexist in palm dominated and native (hereafter dicot dominated) forests across the Central Pacific. These forests differ strongly both in the amount of marine subsidies that they receive from seabird guano and carcasses, and in the physical structure of the habitat. Contrary to other studies, we found that subsidy level had no impact on the abundance of either gecko species; it also did not have any apparent effects on resource partitioning between species. However, it did affect body size, dietary composition, and trophic position of both species. Geckos in subsidized, dicot forests were larger, had higher body condition and more diverse diets, and occupied a much higher trophic position than geckos found in palm dominated, low subsidy level forests. Both direct variation in subsidy levels and associated changes in habitat structure appear to play a role in driving these responses. These results suggest that variation in subsidy levels may drive important behavioral responses in predators, even when their numerical response is limited. Strong changes in trophic position of consumers also suggest that subsidies may drive increasingly complex food webs, with longer overall food chain length. PMID:22899995

McCauley, Douglas J.; Hathaway, Stacie A.; Dirzo, Rodolfo; Fisher, Robert N.

2012-01-01

49

Effects of spatial subsidies and habitat structure on the foraging ecology and size of geckos  

USGS Publications Warehouse

While it is well established that ecosystem subsidies—the addition of energy, nutrients, or materials across ecosystem boundaries—can affect consumer abundance, there is less information available on how subsidy levels may affect consumer diet, body condition, trophic position, and resource partitioning among consumer species. There is also little information on whether changes in vegetation structure commonly associated with spatial variation in subsidies may play an important role in driving consumer responses to subsidies. To address these knowledge gaps, we studied changes in abundance, diet, trophic position, size, and body condition of two congeneric gecko species (Lepidodactylus spp.) that coexist in palm dominated and native (hereafter dicot dominated) forests across the Central Pacific. These forests differ trongly both in the amount of marine subsidies that they receive from seabird guano and carcasses, and in the physical structure of the habitat. Contrary to other studies, we found that subsidy level had no impact on the abundance of either gecko species; it also did not have any apparent effects on resource partitioning between species. However, it did affect body size, dietary composition, and trophic position of both species. Geckos in subsidized, dicot forests were larger, had higher body condition and more diverse diets, and occupied a much higher trophic position than geckos found in palm dominated, low subsidy level forests. Both direct variation in subsidy levels and associated changes in habitat structure appear to play a role in driving these responses. These results suggest that variation in subsidy levels may drive important behavioral responses in predators, even when their numerical response is limited. Strong changes in trophic position of consumers also suggest that subsidies may drive increasingly complex food webs, with longer overall food chain length.

Briggs, Amy A.; Young, Hillary S.; McCauley, Douglas J.; Hathaway, Stacie A.; Dirzo, Rodolfo; Fisher, Robert N.

2012-01-01

50

Behavioral response of the coachwhip (Masticophis flagellum) to habitat fragment size and isolation in an urban landscape  

USGS Publications Warehouse

Habitat fragmentation is a significant threat to biodiversity worldwide. Habitat loss and the isolation of habitat fragments disrupt biological communities, accelerate the extinction of populations, and often lead to the alteration of behavioral patterns typical of individuals in large, contiguous natural areas. We used radio-telemetry to study the space-use behavior of the Coachwhip, a larger-bodied, wide-ranging snake species threatened by habitat fragmentation, in fragmented and contiguous areas of coastal southern California. We tracked 24 individuals at three sites over two years. Movement patterns of Coachwhips changed in habitat fragments. As area available to the snakes was reduced, individuals faced increased crowding, had smaller home-range sizes, tolerated greater home-range overlap, and showed more concentrated movement activity and convoluted movement pathways. The behavioral response shown by Coachwhips suggests, on a regional level, area-effects alone cannot explain observed extinctions on habitat fragments but, instead, suggests changes in habitat configuration are more likely to explain the decline of this species. Ultimately, if "edge-exposure" is a common cause of decline, then isolated fragments, appropriately buffered to reduce emigration and edge effects, may support viable populations of fragmentation-sensitive species.

Mitrovich, Milan J.; Diffendorfer, Jay E.; Fisher, Robert N.

2009-01-01

51

Novel alleles in classical major histocompatibility complex class II loci of the brushtail possum ( Trichosurus vulpecula )  

Microsoft Academic Search

We have investigated the diversity of class II major histocompatibility complex (MHC) loci in the brushtail possum (Trichosurus vulpecula), an important marsupial pest species in New Zealand. Immunocontraceptive vaccines, a method of fertility control that employs\\u000a the immune system to attack reproductive cells or proteins, are currently being researched as a means of population control\\u000a for the possum. Variation has

Olivia J. Holland; Phil E. Cowan; Dianne M. Gleeson; Larry W. Chamley

2008-01-01

52

Variation in Hematological and Serum Biochemical Values of the Mountain Brushtail Possum, Trichosuruscaninus Ogilby (Marsupialia: Phalangeridae)  

Microsoft Academic Search

Hematological and serum bio- chemical values were determined in a wild population of the mountain brushtail possum (Trichosuru.s caninu.s) at Cambarville, central Victoria, southeastern Australia. Animals were sampled during two-week trapping periods in Jtine, September, and December 1992, and April 1993. Values for hemoglobin, red cell count and hematocrit were significantly higher in males than females. Total protein and mean

K. L. Vlggers; D. B. Llndenmayer

1996-01-01

53

Behavior-Based Assessment of the Auditory Abilities of Brushtail Possums  

ERIC Educational Resources Information Center

Brushtail possums ("Trichosurus vulpecula") were trained to press a right lever when a tone was presented (a tone-on trial) and a left lever when a tone was not presented (a tone-off trial) to gain access to food. During training the tone was set at 80 dB(A), with a frequency of 0.88 kH for 3 possums and of 4 kH for the other 2. Once accuracy was…

Osugi, Mizuho; Foster T. Mary; Temple, William; Poling, Alan

2011-01-01

54

The effect of fertility control on the transmission of bovine tuberculosis in wild brushtail possums  

Microsoft Academic Search

AIM: To determine the effect of fertility control on the rate of transmission of bovine tuberculosis (Tb), caused by Mycobacterium bovis, in brushtail possums (Trichosurus vulpecula).METHODS: At two study sites with a history of Tb infection in the resident possum population, a sample of adult male and female possums (n=50), determined by palpation to be Tb-free, was surgically sterilised by

DSL Ramsey; JD Coleman; MC Coleman; P Horton

2006-01-01

55

Relationships between intra-specific variation in seed size and recruitment in four species in two contrasting habitats.  

PubMed

Large seeds contain more stored resources, and seedlings germinating from large seeds generally cope better with environmental stresses such as shading, competition and thick litter layers, than seedlings germinating from small seeds. A pattern with small-seeded species being associated with open habitats and large-seeded species being associated with closed (shaded) habitats has been suggested and supported by comparative studies. However, few studies have assessed the intra-specific relationship between seed size and recruitment, comparing plant communities differing in canopy cover. Here, seeds from four plant species commonly occurring in ecotones between open and closed habitats (Convallaria majalis, Frangula alnus, Prunus padus and Prunus spinosa) were weighed and sown individually (3200 seeds per species) in open and closed-canopy sites, and seedling emergence and survival recorded over 3 years. Our results show a generally positive, albeit weak, relationship between seed size and recruitment. In only one of the species, C. majalis, was there an association between closed canopy habitat and a positive seed size effect on recruitment. We conclude that there is a weak selection gradient favouring larger seeds, but that this selection gradient is not clearly related to habitat. PMID:23066651

Lönnberg, K; Eriksson, O

2013-05-01

56

Heat Loss May Explain Bill Size Differences between Birds Occupying Different Habitats  

PubMed Central

Background Research on variation in bill morphology has focused on the role of diet. Bills have other functions, however, including a role in heat and water balance. The role of the bill in heat loss may be particularly important in birds where water is limiting. Song sparrows localized in coastal dunes and salt marsh edge (Melospiza melodia atlantica) are similar in size to, but have bills with a 17% greater surface area than, those that live in mesic habitats (M. m. melodia), a pattern shared with other coastal sparrows. We tested the hypotheses that sparrows can use their bills to dissipate “dry” heat, and that heat loss from the bill is higher in M. m. atlantica than M. m. melodia, which would indicate a role of heat loss and water conservation in selection for bill size. Methodology/Principal Findings Bill, tarsus, and body surface temperatures were measured using thermal imaging of sparrows exposed to temperatures from 15–37°C and combined with surface area and physical modeling to estimate the contribution of each body part to total heat loss. Song sparrow bills averaged 5–10°C hotter than ambient. The bill of M. m atlantica dissipated up to 33% more heat and 38% greater proportion of total heat than that of M. m. melodia. This could potentially reduce water loss requirements by approximately 7.7%. Conclusions/Significance This >30% higher heat loss in the bill of M. m. atlantica is independent of evaporative water loss and thus could play an important role in the water balance of sparrows occupying the hot and exposed dune/salt marsh environments during the summer. Heat loss capacity and water conservation could play an important role in the selection for bill size differences between bird populations and should be considered along with trophic adaptations when studying variation in bill size. PMID:22848413

Greenberg, Russell; Cadena, Viviana; Danner, Raymond M.; Tattersall, Glenn

2012-01-01

57

Millimeter-Sized Marine Plastics: A New Pelagic Habitat for Microorganisms and Invertebrates  

PubMed Central

Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range?=?1.7–24.3 mm, median?=?3.2 mm) from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse group of plastic colonizers, represented by 14 genera. We also recorded ‘epiplastic’ coccolithophores (7 genera), bryozoans, barnacles (Lepas spp.), a dinoflagellate (Ceratium), an isopod (Asellota), a marine worm, marine insect eggs (Halobates sp.), as well as rounded, elongated, and spiral cells putatively identified as bacteria, cyanobacteria, and fungi. Furthermore, we observed a variety of plastic surface microtextures, including pits and grooves conforming to the shape of microorganisms, suggesting that biota may play an important role in plastic degradation. This study highlights how anthropogenic millimeter-sized polymers have created a new pelagic habitat for microorganisms and invertebrates. The ecological ramifications of this phenomenon for marine organism dispersal, ocean productivity, and biotransfer of plastic-associated pollutants, remains to be elucidated. PMID:24941218

Reisser, Julia; Shaw, Jeremy; Hallegraeff, Gustaaf; Proietti, Maira; Barnes, David K. A.; Thums, Michele; Wilcox, Chris; Hardesty, Britta Denise; Pattiaratchi, Charitha

2014-01-01

58

The ultrastructure of the lung of two newborn marsupial species, the northern native cat, Dasyurus hallucatus , and the brushtail possum, Trichosurus vulpecula  

Microsoft Academic Search

The lungs of newborn northern native cats, Dasyurus hallucatus and newborn brushtail possums, Trichosurus vulpecula were examined by both light and electron microscopy. The native cat has a birth weight of 18 mg after a gestation of about 21 days, whereas the brushtail possum weights 200 mg at birth and has a gestation period of 17.5 days. The lungs of

R. T. Gemmell; J. Nelson

1988-01-01

59

Parallel evolution of the sexes? Effects of predation and habitat features on the size and shape of wild guppies  

Microsoft Academic Search

Environmental gradients often lead to the parallel evolution of populations and species. To what extent do such gradients also lead to parallel evolution of the sexes? We used guppies (Poecilia reticulata) to examine the parallel and independent (sex-specific) aspects of population divergence in response to predation and habitat features. Geometric morphometrics was used to analyse size and shape variation for

A. P. HENDRY; M. L. KELLY; M. T. KINNISON; D. N. REZNICK

2006-01-01

60

Predicting potential habitat and population size for reintroduction of the Far Eastern leopards in the Russian Far East  

E-print Network

Predicting potential habitat and population size for reintroduction of the Far Eastern leopards Leopard (Panthera pardus orientalis; Schlegel, 1857) is perhaps the world's most endan- gered large felid locations of leopard tracks (and their ungulate prey) collected from snow track surveys from 1997 to 2007

Hebblewhite, Mark

61

Size structure of testate amoebae (Arcellinida and Euglyphida) in different habitats from a lake in the upper Paraná River floodplain.  

PubMed

This study aimed to investigate the relationship between the size structure of testate amoebae in distinct habitats, i.e. plankton, aquatic macrophytes and aquatic sediment. The samples were taken from a floodplain lake of the upper Paraná River. The assumptions we strived to scrutinize were that (i) larger mean sizes of testate amoebae would be recorded in the sediment of the lake; and (ii) temporally, smaller individuals would be registered during the high water period in all habitats. The sampling was done monthly, from April 2007 to March 2008, in triplicates for each habitat. Testate amoebae were represented by individuals sized between 20 and 400 ?m. The smaller individuals predominated in plankton samples, while in the aquatic sediment the larger ones were chiefly represented. These differences were probably associated with metabolic activities, i.e. the energy needs of these unicellular organisms, in each habitat. Two-way ANOVA yielded significant differences between hydrological periods. During the high water period, the increase in rainfall and consequently in water flow, decreased the stability of the system and increased turbulence and water column circulation. Therefore, environmental stability seems to be one of the main factors driving the temporal variation in the size structure of these specific organisms. PMID:22261279

Alves, Geziele Mucio; Velho, Luiz Felipe Machado; de Morais Costa, Deise; Lansac-Tôha, Fábio Amodêo

2012-08-01

62

Parallel evolution of the sexes? Effects of predation and habitat features on the size and shape of wild guppies  

E-print Network

Parallel evolution of the sexes? Effects of predation and habitat features on the size and shape population divergence often occurs in parallel for different lineages (e.g. species) arrayed across the same range of selective environments. That is, different lineages settle on similar adaptive solutions

Hendry, Andrew

63

Crayfish predation on the common pond snail (Lymnaea stagnalis): the effect of habitat complexity and snail size on foraging efficiency  

Microsoft Academic Search

Optimal foraging theory was used to explain selective foraging by the introduced signal crayfish (Pacifastacus leniusculus)\\u000a on the thin-shelled common pond snail (Lymnaea stagnalis). Crayfish predation efficiency was studied in relation to habitat\\u000a complexity and snail size. In a pool experiment (area 1.3 m2) single adult crayfish were allowed to feed on four size classes of snails for one week.

Per Nyström; Jose R. Pérez

1998-01-01

64

Hierarchical behaviour, habitat use and species size differences shape evolutionary outcomes of hybridization in a coral reef fish.  

PubMed

Hybridization is an important evolutionary process, with ecological and behavioural factors influencing gene exchange between hybrids and parent species. Patterns of hybridization in anemonefishes may result from living in highly specialized habitats and breeding status regulated by size-based hierarchal social groups. Here, morphological, ecological and genetic analyses in Kimbe Bay, Papua New Guinea, examine the hybrid status of Amphiprion leucokranos, a nominal species and presumed hybrid between Amphiprion sandaracinos and Amphiprion chrysopterus. We test the hypothesis that habitat use and relative size differences of the parent species and hybrids determine the patterns of gene exchange. There is strong evidence that A. leucokranos is a hybrid of smaller A. sandaracinos and larger A. chrysopterus, where A. chrysopterus is exclusively the mother to each hybrid, based on mtDNA cytochrome b and multiple nDNA microsatellite loci. Overlap in habitat, depth and host anemone use was found, with hybrids intermediate to parents and cohabitation in over 25% of anemones sampled. Hybrids, intermediate in body size, colour and pattern, were classified 55% of the time as morphologically first-generation hybrids relative to parents, whereas 45% of hybrids were more A. sandaracinos-like, suggesting backcrossing. Unidirectional introgression of A. chrysopterus mtDNA into A. sandaracinos via hybrid backcrosses was found, with larger female hybrids and small male A. sandaracinos mating. Potential nDNA introgression was also evident through distinct intermediate hybrid genotypes penetrating both parent species. Findings support the hypothesis that anemonefish hierarchical behaviour, habitat use and species-specific size differences determine how hybrids form and the evolutionary consequences of hybridization. PMID:25414094

Gainsford, A; van Herwerden, L; Jones, G P

2015-01-01

65

Concurrent habitat and life history influences on effective/census population size ratios in stream-dwelling trout.  

PubMed

Lower effective sizes (N(e)) than census sizes (N) are routinely documented in natural populations, but knowledge of how multiple factors interact to lower N(e)/N ratios is often limited. We show how combined habitat and life-history influences drive a 2.4- to 6.1-fold difference in N(e)/N ratios between two pristine brook trout (Salvelinus fontinalis) populations occupying streams separated by only 750 m. Local habitat features, particularly drainage area and stream depth, govern trout biomass produced in each stream. They also generate higher trout densities in the shallower stream by favoring smaller body size and earlier age-at-maturity. The combination of higher densities and reduced breeding site availability in the shallower stream likely leads to more competition among breeding trout, which results in greater variance in individual reproductive success and a greater reduction in N(e) relative to N. A similar disparity between juvenile or adult densities and breeding habitat availability is reported for other species and hence may also result in divergent N(e)/N ratios elsewhere. These divergent N(e)/N ratios between adjacent populations are also an instructive reminder for species conservation programs that genetic and demographic parameters may differ dramatically within species. PMID:22822435

Belmar-Lucero, Sebastian; Wood, Jacquelyn L A; Scott, Sherylyne; Harbicht, Andrew B; Hutchings, Jeffrey A; Fraser, Dylan J

2012-03-01

66

Concurrent habitat and life history influences on effective/census population size ratios in stream-dwelling trout  

PubMed Central

Lower effective sizes (Ne) than census sizes (N) are routinely documented in natural populations, but knowledge of how multiple factors interact to lower Ne/N ratios is often limited. We show how combined habitat and life-history influences drive a 2.4- to 6.1-fold difference in Ne/N ratios between two pristine brook trout (Salvelinus fontinalis) populations occupying streams separated by only 750 m. Local habitat features, particularly drainage area and stream depth, govern trout biomass produced in each stream. They also generate higher trout densities in the shallower stream by favoring smaller body size and earlier age-at-maturity. The combination of higher densities and reduced breeding site availability in the shallower stream likely leads to more competition among breeding trout, which results in greater variance in individual reproductive success and a greater reduction in Ne relative to N. A similar disparity between juvenile or adult densities and breeding habitat availability is reported for other species and hence may also result in divergent Ne/N ratios elsewhere. These divergent Ne/N ratios between adjacent populations are also an instructive reminder for species conservation programs that genetic and demographic parameters may differ dramatically within species. PMID:22822435

Belmar-Lucero, Sebastian; Wood, Jacquelyn L A; Scott, Sherylyne; Harbicht, Andrew B; Hutchings, Jeffrey A; Fraser, Dylan J

2012-01-01

67

Hierarchical distance-sampling models to estimate population size and habitat-specific abundance of an island endemic  

USGS Publications Warehouse

Population size and habitat-specific abundance estimates are essential for conservation management. A major impediment to obtaining such estimates is that few statistical models are able to simultaneously account for both spatial variation in abundance and heterogeneity in detection probability, and still be amenable to large-scale applications. The hierarchical distance-sampling model of J. A. Royle, D. K. Dawson, and S. Bates provides a practical solution. Here, we extend this model to estimate habitat-specific abundance and rangewide population size of a bird species of management concern, the Island Scrub-Jay (Aphelocoma insularis), which occurs solely on Santa Cruz Island, California, USA. We surveyed 307 randomly selected, 300 m diameter, point locations throughout the 250-km2 island during October 2008 and April 2009. Population size was estimated to be 2267 (95% CI 1613-3007) and 1705 (1212-2369) during the fall and spring respectively, considerably lower than a previously published but statistically problematic estimate of 12 500. This large discrepancy emphasizes the importance of proper survey design and analysis for obtaining reliable information for management decisions. Jays were most abundant in low-elevation chaparral habitat; the detection function depended primarily on the percent cover of chaparral and forest within count circles. Vegetation change on the island has been dramatic in recent decades, due to release from herbivory following the eradication of feral sheep (Ovis aries) from the majority of the island in the mid-1980s. We applied best-fit fall and spring models of habitat-specific jay abundance to a vegetation map from 1985, and estimated the population size of A. insularis was 1400-1500 at that time. The 20-30% increase in the jay population suggests that the species has benefited from the recovery of native vegetation since sheep removal. Nevertheless, this jay's tiny range and small population size make it vulnerable to natural disasters and to habitat alteration related to climate change. Our results demonstrate that hierarchical distance-sampling models hold promise for estimating population size and spatial density variation at large scales. Our statistical methods have been incorporated into the R package unmarked to facilitate their use by animal ecologists, and we provide annotated code in the Supplement.

Sillett, Scott T.; Chandler, Richard B.; Royle, J. Andrew; Kéry, Marc; Morrison, Scott A.

2012-01-01

68

SEROLOGIC SURVEY FOR TOXOPLASMA GONDII AND NEOSPORA CANINUM IN THE COMMON BRUSHTAIL POSSOM (TRICHOSURUS VULPECULA) FROM URBAN SYDNEY, AUSTRALIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

The common brushtail possum (Trichosurus vulpecula) has well adapted to increasing urbanization resulting in greater interaction with humans and their domestic pets. Wildlife species in urban areas face a higher risk of exposure to zoonotic pathogens and may be affected by parasites hosted by cats (...

69

EXPERIMENTAL INFECTIONS OF BRUSH-TAILED POSSUMS, COMMON WOMBATS AND WATER RATS WITH LEPTOSPIRA INTERROGANS SEROVARS BALCANICA AND HARDJO  

Microsoft Academic Search

Of 12 brush-tailed possums (Trichosurus vulpecula) inoculated with Leptospira interrogans serovar balcanica 11 developed migroagglutination (MA) antibody to hardjo antigen by 14 days postinoculation (PI). Leptospiruria was observed in 2 possums 117 to 145 days PI. Of 6 possums inoculated with serovar hardjo 4 developed low short-lived titres by day 18 PI. Two of 3 wombats (Vombatus ursinus) inoculated with

Philip T Durfee; Paul JA Presidente

1979-01-01

70

Higher mobility of butterflies than moths connected to habitat suitability and body size in a release experiment  

PubMed Central

Mobility is a key factor determining lepidopteran species responses to environmental change. However, direct multispecies comparisons of mobility are rare and empirical comparisons between butterflies and moths have not been previously conducted. Here, we compared mobility between butterflies and diurnal moths and studied species traits affecting butterfly mobility. We experimentally marked and released 2011 butterfly and 2367 moth individuals belonging to 32 and 28 species, respectively, in a 25 m × 25 m release area within an 11-ha, 8-year-old set-aside field. Distance moved and emigration rate from the release habitat were recorded by species. The release experiment produced directly comparable mobility data in 18 butterfly and 9 moth species with almost 500 individuals recaptured. Butterflies were found more mobile than geometroid moths in terms of both distance moved (mean 315 m vs. 63 m, respectively) and emigration rate (mean 54% vs. 17%, respectively). Release habitat suitability had a strong effect on emigration rate and distance moved, because butterflies tended to leave the set-aside, if it was not suitable for breeding. In addition, emigration rate and distance moved increased significantly with increasing body size. When phylogenetic relatedness among species was included in the analyses, the significant effect of body size disappeared, but habitat suitability remained significant for distance moved. The higher mobility of butterflies than geometroid moths can largely be explained by morphological differences, as butterflies are more robust fliers. The important role of release habitat suitability in butterfly mobility was expected, but seems not to have been empirically documented before. The observed positive correlation between butterfly size and mobility is in agreement with our previous findings on butterfly colonization speed in a long-term set-aside experiment and recent meta-analyses on butterfly mobility. PMID:25614794

Kuussaari, Mikko; Saarinen, Matias; Korpela, Eeva-Liisa; Pöyry, Juha; Hyvönen, Terho

2014-01-01

71

Habitat Size Optimization of the O'Neill - Glaser Economic Model for Space Solar Satellite Production  

NASA Technical Reports Server (NTRS)

Creating large space habitats by launching all materials from Earth is prohibitively expensive. Using space resources and space based labor to build space solar power satellites can yield extraordinary profits after a few decades. The economic viability of this program depends on the use of space resources and space labor. To maximize the return on the investment, the early use of high density bolo habitats is required. Other shapes do not allow for the small initial scale required for a quick population increase in space. This study found that 5 Man Year, or 384 person bolo high density habitats will be the most economically feasible for a program started at year 2010 and will cause a profit by year 24 of the program, put over 45,000 people into space, and create a large system of space infrastructure for the further exploration and development of space.

Curreri, Peter A.; Detweiler, Michael

2010-01-01

72

Does size matter? An investigation of habitat use across a carnivore assemblage in the Serengeti, Tanzania.  

PubMed

1. This study utilizes a unique data set covering over 19 000 georeferenced records of species presence collected between 1993 and 2008, to explore the distribution and habitat selectivity of an assemblage of 26 carnivore species in the Serengeti-Ngorongoro landscape in northern Tanzania. 2. Two species, the large-spotted genet and the bushy-tailed mongoose, were documented for the first time within this landscape. Ecological Niche Factor Analysis (ENFA) was used to examine habitat selectivity for 18 of the 26 carnivore species for which there is sufficient data. Eleven ecogeographical variables (EGVs), such as altitude and habitat type, were used for these analyses. 3. The ENFA demonstrated that species differed in their habitat selectivity, and supported the limited ecological information already available for these species, such as the golden jackals' preference for grassland and the leopards' preference for river valleys. 4. Two aggregate scores, marginality and tolerance, are generated by the ENFA, and describe each species' habitat selectivity in relation to the suite of EGVs. These scores were used to test the hypothesis that smaller species are expected to be more selective than larger species [Science, 1989, 243, 1145]. Two predictions were tested: Marginality should decrease with body mass; and tolerance should increase with body mass. Our study provided no evidence for either prediction. 5. Our results not only support previous analyses of carnivore diet breadth, but also represent a novel approach to the investigation of habitat selection across species assemblages. Our method provides a powerful tool to explore similar questions in other systems and for other taxa. PMID:20646121

Durant, Sarah M; Craft, Meggan E; Foley, Charles; Hampson, Katie; Lobora, Alex L; Msuha, Maurus; Eblate, Ernest; Bukombe, John; McHetto, John; Pettorelli, Nathalie

2010-09-01

73

The consequences of introducing non-indigenous species: two case studies, the grey squirrel in Europe and the brushtail possum in New Zealand.  

PubMed

Two examples of the introduction of non-indigenous invasive species are reviewed: the grey squirrel in Europe (United Kingdom, Ireland and Italy) and the brushtail possum in New Zealand. Both have become very successful in their respective non-native habitats since their introductions in the mid-to-late 19th Century. Both species impact extensively on native biodiversity, environmental sustainability, forestry, and agriculture through a range of direct and indirect mechanisms. Management is currently mainly by lethal control, namely poisoning, trapping and shooting. Such methods of control are, however, increasingly contentious for both species, and alternative, non-lethal methods of population control, e.g. fertility control, are being developed. The case studies highlight many of the issues in invasive animal control; for example, prevention being better than control, lack of good understanding of impacts and the success of control measures on reducing impacts, interactive impacts on native biodiversity and ecosystems, the telling influence of public opinion on management options and, lastly, the need to better inform and educate the public. PMID:20919583

Lawton, C; Cown, P; Bertolino, S; Lurz, P W W; Peters, A R

2010-08-01

74

THE RELATIONSHIP BETWEEN MACROPHYTE VEGETATION AND HABITAT FACTORS ALONG A MIDDLE-SIZE EUROPEAN RIVER  

Microsoft Academic Search

The influence of habitat factors on macrophytes distribution was studied along the Hron river - one of the longest Slovakian rivers (length 298 km; average flow rate - 56 m3 s-1 near the outfall into the Danube) and important tribu- tary of the Danube river. Along the river bed, 19 sections were selected according to approximately regular distances and with

Richard HRIVNÁK

75

Size and depth-dependent variation in habitat and diet of the common carp ( Cyprinus carpio )  

Microsoft Academic Search

The habitat and diet variation of the common carp (Cyprinus carpio) were studied in Lake Banyoles (Catalonia, Spain). Carp was the second most abundant species offshore and used more the littoral in spring and deep bottoms in winter. The diet of carp was based on detritus, amphipods (Echinogammarus sp.), phantom midge larvae (Chaoborus flavicans), diatom mucilages, and plant debris. Amphipods

Emili García-Berthou

2001-01-01

76

SHALLOW HABITATS IN TWO RHODE ISLAND SYSTEMS: II. PATTERNS OF SIZE, STRUCTURE AND FUNCTIONAL GROUPS  

EPA Science Inventory

We are examining habitats in small estuarine coves that may be important for the development of ecological indicators of integrity. We sampled nekton in Coggeshall Cove (shallow estuarine cove) in summer 1999 and 2000 and Ninigret Pond (coastal lagoon) in summer 2000. Coggeshall ...

77

Big, sick, and rotting: why tree size, damage, and decay are important to fisher reproductive habitat  

Microsoft Academic Search

To gain a better understanding of the factors affecting selection of reproductive habitat by female fishers (Martes pennanti) in boreal mixed-wood forests, we identified structures, sites, and stands used by 12 radiotagged female fishers for reproduction between 2005 and 2009 near Dawson Creek, British Columbia, Canada. We deployed a used-unused design to evaluate the support by the data for a

Richard D. Weir; E. Mark Phinney; Eric C. Lofroth

78

Selection based on the size of the black tie of the great tit may be reversed in urban habitats  

PubMed Central

A standard approach to model how selection shapes phenotypic traits is the analysis of capture–recapture data relating trait variation to survival. Divergent selection, however, has never been analyzed by the capture–recapture approach. Most reported examples of differences between urban and nonurban animals reflect behavioral plasticity rather than divergent selection. The aim of this paper was to use a capture–recapture approach to test the hypothesis that divergent selection can also drive local adaptation in urban habitats. We focused on the size of the black breast stripe (i.e., tie width) of the great tit (Parus major), a sexual ornament used in mate choice. Urban great tits display smaller tie sizes than forest birds. Because tie size is mostly genetically determined, it could potentially respond to selection. We analyzed capture/recapture data of male great tits in Barcelona city (N = 171) and in a nearby (7 km) forest (N = 324) from 1992 to 2008 using MARK. When modelling recapture rate, we found it to be strongly influenced by tie width, so that both for urban and forest habitats, birds with smaller ties were more trap-shy and more cautious than their larger tied counterparts. When modelling survival, we found that survival prospects in forest great tits increased the larger their tie width (i.e., directional positive selection), but the reverse was found for urban birds, with individuals displaying smaller ties showing higher survival (i.e., directional negative selection). As melanin-based tie size seems to be related to personality, and both are heritable, results may be explained by cautious personalities being favored in urban environments. More importantly, our results show that divergent selection can be an important mechanism in local adaptation to urban habitats and that capture–recapture is a powerful tool to test it. PMID:25077014

Senar, Juan Carlos; Conroy, Michael J; Quesada, Javier; Mateos-Gonzalez, Fernando

2014-01-01

79

Selection based on the size of the black tie of the great tit may be reversed in urban habitats.  

PubMed

A standard approach to model how selection shapes phenotypic traits is the analysis of capture-recapture data relating trait variation to survival. Divergent selection, however, has never been analyzed by the capture-recapture approach. Most reported examples of differences between urban and nonurban animals reflect behavioral plasticity rather than divergent selection. The aim of this paper was to use a capture-recapture approach to test the hypothesis that divergent selection can also drive local adaptation in urban habitats. We focused on the size of the black breast stripe (i.e., tie width) of the great tit (Parus major), a sexual ornament used in mate choice. Urban great tits display smaller tie sizes than forest birds. Because tie size is mostly genetically determined, it could potentially respond to selection. We analyzed capture/recapture data of male great tits in Barcelona city (N = 171) and in a nearby (7 km) forest (N = 324) from 1992 to 2008 using MARK. When modelling recapture rate, we found it to be strongly influenced by tie width, so that both for urban and forest habitats, birds with smaller ties were more trap-shy and more cautious than their larger tied counterparts. When modelling survival, we found that survival prospects in forest great tits increased the larger their tie width (i.e., directional positive selection), but the reverse was found for urban birds, with individuals displaying smaller ties showing higher survival (i.e., directional negative selection). As melanin-based tie size seems to be related to personality, and both are heritable, results may be explained by cautious personalities being favored in urban environments. More importantly, our results show that divergent selection can be an important mechanism in local adaptation to urban habitats and that capture-recapture is a powerful tool to test it. PMID:25077014

Senar, Juan Carlos; Conroy, Michael J; Quesada, Javier; Mateos-Gonzalez, Fernando

2014-07-01

80

Morphology of the lingual papillae in the brush-tailed rat kangaroo.  

PubMed

We examined the dorsal lingual surface of an adult brush-tailed rat kangaroo (Bettongia penicillata) by scanning electron microscopy. The filiform and fungiform papillae on the lingual apex and body consisted of a main papilla and secondary papillae. The connective tissue core of the filiform papillae on the lingual apex was cylindrical in shape with a crushed top. The connective tissue core of the filiform papillae on the lingual body had one large and several small processes. The fungiform papillae were round in shape. The connective tissue core of the fungiform papillae had several depressions on its top. The surface of the vallate papillae was rough and the papillae were surrounded by a groove and a pad. Several long conical papillae derived from the posterolateral margin of the tongue where foliate papillae have been shown to be distributed in many other animal species. The long conical papillae were very similar to those of the koala and opossum. PMID:24815106

Emura, Shoichi; Okumura, Toshihiko; Chen, Huayue

2014-01-01

81

Endogenous Type D Retrovirus in a Marsupial, the Common Brushtail Possum (Trichosurus vulpecula)  

PubMed Central

We have sequenced and characterized an endogenous type D retrovirus, which we have named TvERV(D), from the genome of an Australian marsupial, the common brushtail possum (Trichosurus vulpecula). Intact TvERV(D) gag, pro, pol, and env open reading frames were detected in the possum genome. TvERV(D) was classified as a type D retrovirus, most closely related to those of Old World monkeys, New World monkeys, and mice, based on phylogenetic analyses and genetic organization. Approximately 30 TvERV(D) proviruses are present in the genomes of possums, as detected by Southern hybridization. However, variability in fragment patterns between possums was observed and suggests recent (or ongoing) retrotranspositional activity. PMID:11160757

Baillie, Gregory J.; Wilkins, Richard J.

2001-01-01

82

Cortico-cortical connections of the motor cortex in the brushtailed possum (Trichosurus vulpecula).  

PubMed Central

Cortico-cortical connections of motor cortex in the marsupial brushtailed possum were traced by making injections of horseradish peroxidase (HRP) into two parts of motor cortex: the rostral agranular part which does not overlap somatosensory cortex, and the caudal part which does. Following injections in motor cortex, labelled neurons were observed on the same side of the brain within somatosensory areas 1 and 2 and in parietal cortex just caudal to S1, with most neurons in cortical Layers 2-4. Commissural connections were found in half of the experiments, with many labelled neurons in cortical Layer 5. We have compared the pattern of cortico-cortical connections in the possum with those seen in some other mammals, which appear generally similar. Images Fig. 4 Fig. 6 PMID:3115935

Joschko, M A; Sanderson, K J

1987-01-01

83

Prevalence and spatial distribution of bovine tuberculosis in brushtail possums on a forest-scrub margin.  

PubMed

Tuberculosis caused by Mycobacterium bovis was diagnosed in 36 of 68 (53%) brushtail possums (Trichosurus vulpecula) trapped in August 1992 from a population of exceptionally low density (trap catch <3%) on a forest-scrub margin in Westland, New Zealand. The prevalence of tuberculosis in possums, based solely on gross lesions, was at least twice that previously recorded in New Zealand, and was about seven times that recorded from the same population in 1980. More male (66%) than female (33%) possums had grossly visible tuberculous lesions. The distribution of infection appeared continuous along the forest-scrub margin. Both stoats (Mustela erminea) and one of six hares (Lepus europaeus occidentalis) trapped were also infected with M. bovis. PMID:16031762

Coleman, J D; Jackson, R; Cooke, M M; Grueber, L

1994-08-01

84

Habitat Patch Size, Facultative Monogamy and Sex Change in a Coral-dwelling Fish, Caracanthus unipinna  

Microsoft Academic Search

We investigated the inter-relationships between coral colony size, social group size, mating system, and patterns of sex allocation in the pygmy coral croucher, Caracanthus unipinna (Caracanthidae), an obligate coral-dwelling fish. Histological examination of the gonads from all individuals in social groups revealed that the predominant mating system was harem polygyny. However, both group size and mating system co-varied with coral

Marian Y. L. Wong; Philip L. Munday; Geoffrey P. Jones

2005-01-01

85

Size-dependent distribution and feeding habits of Terebralia palustris in mangrove habitats of Gazi Bay, Kenya  

NASA Astrophysics Data System (ADS)

The gastropod Terebralia palustris often dominates the surface of muddy to sandy substrates of intertidal mudflats and mangrove forests, where they clearly destabilize the sediment. In the present study, it was investigated whether and to what extent the behaviour of juvenile and adult snails differs among habitats (mudflat vs. mangrove stand) in a Sonneratia alba mangal at Gazi Bay, Kenya. For this purpose we: (1) examined their distribution along three land-sea transects; and (2) applied stable isotope analysis to determine the feeding patterns of different-sized snails from the mangrove and mudflat habitats. Additionally, we investigated if these gastropods exert an impact on microphytobenthic (diatom) biomass, and whether this is size-dependent. The latter objective was met by either enclosing or excluding different-sized snails from experimental cages on the intertidal mudflat and the subsequent assessment of a change in pigment concentration of the sediment surface. In agreement with several previous studies conducted in other mangroves and geographical locations, a spatial segregation was demonstrated between juveniles (more common on the mudflat) and adults (more common in the mangrove forest). On the intertidal mudflat juveniles avoided sediment patches characterized by highly saline water in intertidal pools and a high mud content, while adults tended to dwell on substrates covered by a high amount of leaf litter. Stable carbon isotope analysis of the foot tissue of snails sampled from the S. alba stand and the mudflat indicated a transition in food source when a shell length of 51 mm is reached. Considering the ?13C value of juveniles, it seems they might be selecting for microphytobenthos, which might explain their preference for the mudflat. The diet of size classes found in both habitats did not differ significantly, although juveniles inhabiting the mangrove forest were slightly more depleted in 13C compared to those residing on the mudflat. Assuming juveniles feed on benthic microalgae and considering the lower microalgal biomass inside the mangrove forest, this may be a consequence of a higher contribution of other, more 13C depleted organic carbon sources, like phytoplankton, to their diet. Experimental results indicate a negative, but insignificant, impact on benthic diatom biomass by juveniles (due to grazing) and adults (due to physical disturbance). This finding seems to be in agreement with the results of the stable carbon isotope analysis, strongly suggesting the selective feeding of juvenile T. palustris on benthic diatoms.

Pape, Ellen; Muthumbi, Agnes; Kamanu, Chomba Peter; Vanreusel, Ann

2008-03-01

86

Plasma growth hormone and growth hormone-binding protein during development in the marsupial brushtail possum (Trichosurus vulpecula)  

Microsoft Academic Search

Plasma concentrations of growth hormone (GH) were measured in the brushtail possum (Trichosurus vulpecula) pouch young from 25 through to 198 days post-partum (n=71). GH concentrations were highest early in pouch life (around 100 ng\\/ml), and thereafter declined in an exponential fashion to reach adult concentrations (10·81·8 ng\\/ml; n=21) by approximately 121-145 days post-partum, one to two months before the

M C Saunders; R T Gemmell; M J Waters; J D Curlewis

2002-01-01

87

Longevity of Mycobacterium bovis in brushtail possum (Trichosurus vulpecula) carcasses, and contact rates between possums and carcasses  

Microsoft Academic Search

AIM: To determine, for a variety of environmental conditions, how long Mycobacterium bovis might remain viable inside the carcass of a brushtail possum (Trichosurus vulpecula) that died of bovine tuberculosis (Tb), and to measure the rate of contact between free-ranging possums and possum carcasses.METHODS: Lesions of M. bovis were simulated by inoculating excised spleens weighing 0.5–1 g with 0.2 mL liquid

MC Barron; RP Pech; J Whitford; IJ Yockney; GW de Lisle; G Nugent

2011-01-01

88

Time–activity budget of greater rheas ( Rhea americana , Aves) on a human-disturbed area: the role of habitat, time of the day, season and group size  

Microsoft Academic Search

The aim of this study was to evaluate activity–time budget, habitat use and how seasonality and group size influence the expression\\u000a of greater rhea behaviours. Greater rheas are threatened South American birds; habitat loss, predation and hunting are the\\u000a main factors responsible for population declines. The study was conducted in farmlands within a matrix of commercial Eucalyptus plantation and remnants

Cristiano Schetini de Azevedo; João Bosco Ferraz; Herlandes Penha Tinoco; Robert John Young; Marcos Rodrigues

2010-01-01

89

Habitat complexity and fish size affect the detection of Indo-Pacific lionfish on invaded coral reefs  

NASA Astrophysics Data System (ADS)

A standard approach to improving the accuracy of reef fish population estimates derived from underwater visual censuses (UVCs) is the application of species-specific correction factors, which assumes that a species' detectability is constant under all conditions. To test this assumption, we quantified detection rates for invasive Indo-Pacific lionfish ( Pterois volitans and P. miles), which are now a primary threat to coral reef conservation throughout the Caribbean. Estimates of lionfish population density and distribution, which are essential for managing the invasion, are currently obtained through standard UVCs. Using two conventional UVC methods, the belt transect and stationary visual census (SVC), we assessed how lionfish detection rates vary with lionfish body size and habitat complexity (measured as rugosity) on invaded continuous and patch reefs off Cape Eleuthera, the Bahamas. Belt transect and SVC surveys performed equally poorly, with both methods failing to detect the presence of lionfish in >50 % of surveys where thorough, lionfish-focussed searches yielded one or more individuals. Conventional methods underestimated lionfish biomass by ~200 %. Crucially, detection rate varied significantly with both lionfish size and reef rugosity, indicating that the application of a single correction factor across habitats and stages of invasion is unlikely to accurately characterize local populations. Applying variable correction factors that account for site-specific lionfish size and rugosity to conventional survey data increased estimates of lionfish biomass, but these remained significantly lower than actual biomass. To increase the accuracy and reliability of estimates of lionfish density and distribution, monitoring programs should use detailed area searches rather than standard visual survey methods. Our study highlights the importance of accounting for sources of spatial and temporal variation in detection to increase the accuracy of survey data from coral reef systems.

Green, S. J.; Tamburello, N.; Miller, S. E.; Akins, J. L.; Côté, I. M.

2013-06-01

90

Distribution, habitat, size, and color pattern of Cnemidophorus lemniscatus (Sauria: Teiidae) on Cayo Cochino Pequen??o, Honduras  

USGS Publications Warehouse

Cayo Cochino Pequen??o is a 0.64-km2 Caribbean island in the Cayos Cochinos archipelago, Department of Islas de la Bahi??a, Honduras. One published report noted the presence of the rainbow whiptail (Cnemidophorus lemniscatus) on Cayo Cochino Pequen??o, but nothing is known about the biology of this insular population. During a part of the dry season in July and August 2004, we used drift fences, pitfall traps, and separate observational transects to elucidate the distribution and habitat use of C. lemniscatus on the island. The only population of this species was located in a narrow coastal zone (width to 60 m and length to 450 m) on the southern half of the eastern windward side of the island. We analyzed the percentage of the canopy cover and the percentage of 4 ground coverage types along 2 transects 200 m long in this area to understand the basis of the suitability of the habitat for C. lemniscatus. Descriptively, the area harboring this species on Cayo Cochino Pequen??o consisted of the remnants of a coconut palm grove with low-lying herbaceous vegetation and grasses, in which a mosaic of small, open areas of sandy soil and coral fragments, with or without accumulations of debris, were the foci of lizard activities. Also observed in this habitat were 2 individuals of the brown racer (Dryadophis melanolomus), an actively foraging snake and likely predator on C. lemniscatus. Data obtained on rainbow whiptails captured in pitfall traps and subsequently released were used to determine the size and color patterns of hatchlings and adult males and females.

Montgomery, C.E.; Reed, R.N.; Shaw, H.J.; Boback, S.M.; Walker, J.M.

2007-01-01

91

Interacting Watershed Size and Landcover Influences on Habitat and Biota of Lake Superior Coastal Wetlands  

EPA Science Inventory

Coastal wetlands are important contributors to the productivity and biodiversity of large lakes and important mediators of the lake - watershed connection. This study explores how strength of connection to the watershed (represented by watershed size and wetland morphological ty...

92

Habitat-specific size structure variations in periwinkle populations ( Littorina littorea) caused by biotic factors  

Microsoft Academic Search

Shell size distribution patterns of marine gastropod populations may vary considerably across different environments. We investigated\\u000a the size and density structure of genetically continuous periwinkle populations (Littorina littorea) on an exposed rocky and a sheltered sedimentary environment on two nearby islands in the south-eastern North Sea (German\\u000a Bight). On the sedimentary shore, periwinkle density (917 ± 722 individuals m?2) was about three

Nina Eschweiler; Markus Molis; Christian Buschbaum

2009-01-01

93

Flock size and habitat-dependent food and energy intake of foraging Goldfinches  

Microsoft Academic Search

During the breeding season Goldfinches (Carduelis carduelis L.) feed on milky ripe seeds of about 20 food plants. Individual Goldfinches joining a flock reduce the time spent vigilant with increasing flock size. Therefore birds feeding in flocks get an increased intake of kernels per time unit. This was measured for five different food plants (Dactylis glomerata (Gramineae), Knautia arvensis (Dipsacaceae),

Erich Gliick; Lehrstuhl ffir Biologie

1986-01-01

94

PERMANENT GENETIC RESOURCES NOTE 871 Franken RJ, Hik DS (2004) Influence of habitat quality, patch size,  

E-print Network

quality, patch size, and connectivity on colonization and extinction dynamics of collared pikas (Ochotona collaris). Journal of Animal Ecology, 73, 889­896. Hamilton MB, Pincus EL, Di Fiore A, Fleischer RC (1999 patterns. Journal of Animal Ecology, 76, 899­907. Park SDE (2001) Trypanotolerance in West African cattle

95

The spatial distribution and size of rook (Corvus frugilegus) breeding colonies is affected by both the distribution of foraging habitat and by intercolony competition.  

PubMed Central

Explanations for the variation in the number of nests at bird colonies have focused on competitive or habitat effects without considering potential interactions between the two. For the rook, a colonial corvid which breeds seasonally but forages around the colony throughout the year, both the amount of foraging habitat and its interaction with the number of competitors from surrounding colonies are important predictors of colony size. The distance over which these effects are strongest indicates that, for rooks, colony size may be limited outside of the breeding season when colony foraging ranges are larger and overlap to a greater extent. PMID:10983832

Griffin, L R; Thomas, C J

2000-01-01

96

Lipid-formulated bcg as an oral-bait vaccine for tuberculosis: vaccine stability, efficacy, and palatability to brushtail possums (Trichosurus vulpecula) in New Zealand.  

PubMed

Bovine tuberculosis (Tb), due to infection with virulent Mycobacterium bovis, represents a threat to New Zealand agriculture due to vectorial transmission from wildlife reservoir species, principally the introduced Australian brushtail possum (Trichosurus vulpecula). An oral-delivery wildlife vaccine has been developed to immunize possums against Tb, based on formulation of the human Tb vaccine (M. bovis BCG) in edible lipid matrices. Here BCG bacilli were shown to be stable in lipid matrix formulation for over 8 mo in freezer storage, for 7 wk under room temperature conditions, and for 3-5 wk under field conditions in a forest/pasture margin habitat (when maintained in weatherproof bait-delivery sachets). Samples of the lipid matrix were flavored and offered to captive possums in a bait-preference study: a combination of 10% chocolate powder with anise oil was identified as the most effective attractant/palatability combination. In a replicated field study, 85-100% of wild possums were shown to access chocolate-flavored lipid pellets, when baits were applied to areas holding approximately 600-800 possums/km(2). Finally, in a controlled vaccination/challenge study, chocolate-flavored lipid vaccine samples containing 10(8) BCG bacilli were fed to captive possums, which were subsequently challenged via aerosol exposure to virulent M. bovis: vaccine immunogenicity was confirmed, and protection was identified by significantly reduced postchallenge weight loss in vaccinated animals compared to nonvaccinated controls. These studies indicate that, appropriately flavored, lipid delivery matrices may form effective bait vaccines for the control of Tb in wildlife. PMID:19617486

Cross, Martin L; Henderson, Ray J; Lambeth, Matthew R; Buddle, Bryce M; Aldwell, Frank E

2009-07-01

97

Do free-ranging common brushtail possums (Trichosurus vulpecula) play a role in the transmission of Toxoplasma gondii within a zoo environment?  

PubMed

To investigate the possible role of common brushtail possums (Trichosurus vulpecula) in the transmission of Toxoplasma gondii within a zoo environment, a serological survey of a free-ranging population resident within Taronga Zoo, Sydney, Australia was undertaken using the modified agglutination test (MAT). For comparison, the seroprevalence of T. gondii antibodies was also assessed in a possum population inhabiting a felid-free, non-urban woodland habitat. Six of 126 possums (4.8%) from the zoo population had antibodies to T. gondii with a MAT titre of 25 or higher, while in contrast, all of the 17 possums from woodland were seronegative. These observations suggest that possums were at a higher risk of exposure to the parasite as a consequence of co-existing with domestic, stray and captive felids associated with urbanisation. Screening of captive felids at the zoo indicated 16 of 23 individuals (67%) and all 6 species were seropositive for T. gondii, implicating them as a possible source of the parasite within the zoo setting. In addition captive, non-felid carnivores including the chimpanzee (Pan troglodytes), saltwater crocodile (Crocodylus porosus), dingo (Canis lupis) and leopard seal (Hydrurga leptonyx) were tested for the presence of T. gondii antibodies as these species predate and are a leading cause of death amongst zoo possums. In total, 5 of 23 individuals (22%) were seropositive, representing 2 of the 4 carnivorous species; the dingo and chimpanzee. These data suggest that carnivory was not a highly efficient pathway for the transmission of T. gondii and the free-ranging possum population posed minimal threat to the health of zoo animals. PMID:18281157

Hill, N J; Dubey, J P; Vogelnest, L; Power, M L; Deane, E M

2008-04-15

98

Habitat-specific size structure variations in periwinkle populations ( Littorina littorea) caused by biotic factors  

NASA Astrophysics Data System (ADS)

Shell size distribution patterns of marine gastropod populations may vary considerably across different environments. We investigated the size and density structure of genetically continuous periwinkle populations ( Littorina littorea) on an exposed rocky and a sheltered sedimentary environment on two nearby islands in the south-eastern North Sea (German Bight). On the sedimentary shore, periwinkle density (917 ± 722 individuals m-2) was about three times higher than on the rocky shore (296 ± 168 individuals m-2). Mean (9.8 ± 3.9 mm) and maximum (22 mm) shell size of L. littorea on the sedimentary shore were smaller than on the rocky shore (21.5 ± 4.2 and 32 mm, respectively), where only few small snails were found. Additionally, periwinkle shells were thicker and stronger on the rocky than on the sedimentary shore. To ascertain mechanisms responsible for differences in population structures, we examined periwinkles in both environments for growth rate, predation pressure, infection with a shell boring polychaete ( Polydora ciliata) and parasitic infestation by trematodes. A crosswise transplantation experiment revealed better growth conditions on the sedimentary than on the rocky shore. However, crab abundance and prevalence of parasites and P. ciliata in adult snails were higher on the sedimentary shore. Previous investigations showed that crabs prefer large periwinkles infested with P. ciliata. Thus, we suggest that parasites and shell boring P. ciliata in conjunction with an increased crab predation pressure are responsible for low abundances of large periwinkles on the sedimentary shore while high wave exposure may explain low densities of juvenile L. littorea on the rocky shore. We conclude that biotic factors may strongly contribute to observed differences in size structure of the L. littorea populations studied on rocky and sedimentary shores.

Eschweiler, Nina; Molis, Markus; Buschbaum, Christian

2009-06-01

99

Relation of ramet size to acorn production in five oak species of xeric upland habitats in south-central Florida.  

PubMed

This study examined variation in two components of acorn production. Percentage of bearing ramets (stems) and number of acorns per bearing ramet were examined in five clonal oaks in three xeric habitats of south-central peninsular Florida in relation to ramet size within and between species and vegetative associations. Counts of acorns on two white oaks (Quercus chapmanii and Q. geminata) and three red oaks (Q. inopina, Q. laevis, and Q. myrtifolia) were conducted annually from 1969 to 1996 (except in 1991) on permanent grids in southern ridge sandhill, sand pine scrub, and scrubby flatwoods associations at the Archbold Biological Station, Florida, USA. Percentage of bearing individuals and mean number of acorns per bearing individual increased with increasing ramet size for all species across all vegetation associations. However, in Q. geminata and Q. myrtifolia, acorn production declined in the largest size class (>3.2 m), implying that larger individuals of these clonal species may become senescent. All oak species in sand pine scrub, which had a nearly closed overstory, had lower frequencies of bearing oaks and mean numbers of acorns compared with similar-sized individuals of the same species in the more open-canopied southern ridge sandhill and scrubby flatwoods associations, suggesting light limitation. The annual production of acorns by a given oak species was correlated across vegetative associations and annual acorn production of oak species was correlated for species within the same section. Intermediate-size class oaks contributed the most acorns per unit area, suggesting that stands managed with short fire-return times will provide fewer acorns to wildlife than stands managed to produce more variable distributions of oak size classes. However, our study suggests that long-unburned stands, such as those studied here, will maintain relatively constant levels of acorn production as a consequence of ramet replacement within the clones of these shrubby oaks to create a variable distribution of size classes. Of the oak species studied, Q. myrtifolia had the highest acorn production and the smallest acorns, while Q. laevis had the lowest acorn production and the largest acorns, suggesting an allocation trade-off between acorn numbers and size. PMID:21669720

Abrahamson, Warren G; Layne, James N

2002-01-01

100

Creating new evolutionary pathways through bioinvasion: the population genetics of brushtail possums in New Zealand.  

PubMed

Rapid increases in global trade and human movement have created novel mixtures of organisms bringing with them the potential to rapidly accelerate the evolution of new forms. The common brushtail possum (Trichosurus vulpecula), introduced into New Zealand from Australia in the 19th century, is one such species having been sourced from multiple populations in its native range. Here, we combine microsatellite DNA- and GIS-based spatial data to show that T. vulpecula originating from at least two different Australian locations exhibit a population structure that is commensurate with their introduction history and which cannot be explained by landscape features alone. Most importantly, we identify a hybrid zone between the two subspecies which appears to function as a barrier to dispersal. When combined with previous genetic, morphological and captive studies, our data suggest that assortative mating between the two subspecies may operate at a behavioural or species recognition level rather than through fertilization, genetic incompatibility or developmental inhibition. Nevertheless, hybridization between the two subspecies of possum clearly occurs, creating the opportunity for novel genetic combinations that would not occur in their natural ranges and which is especially likely given that multiple contact zones occur in New Zealand. This discovery has implications for wildlife management in New Zealand because multiple contact zones are likely to influence the dispersal patterns of possums and because differential susceptibility to baiting with sodium fluoroacetate between possums of different origins may promote novel genetic forms. PMID:24943509

Sarre, Stephen D; Aitken, Nicola; Adamack, Aaron T; MacDonald, Anna J; Gruber, Bernd; Cowan, Phil

2014-07-01

101

Oral vaccination reduces the incidence of tuberculosis in free-living brushtail possums  

PubMed Central

Bovine tuberculosis (Tb) caused by Mycobacterium bovis has proved refractory to eradication from domestic livestock in countries with wildlife disease reservoirs. Vaccination of wild hosts offers a way of controlling Tb in livestock without wildlife culling. This study was conducted in a Tb-endemic region of New Zealand, where the introduced Australian brushtail possum (Trichosurus vulpecula) is the main wildlife reservoir of Tb. Possums were trapped and vaccinated using a prototype oral-delivery system to deliver the Tb vaccine bacille Calmette–Guerin. Vaccinated and control possums were matched according to age, sex and location, re-trapped bimonthly and assessed for Tb status by palpation and lesion aspiration; the site was depopulated after 2 years and post-mortem examinations were conducted to further identify clinical Tb cases and subclinical infection. Significantly fewer culture-confirmed Tb cases were recorded in vaccinated possums (1/51) compared with control animals (12/71); the transition probability from susceptible to infected was significantly reduced in both males and females by vaccination. Vaccine efficacy was estimated at 95 per cent (87–100%) for females and 96 per cent (82–99%) for males. Hence, this trial demonstrates that orally delivered live bacterial vaccines can significantly protect wildlife against natural disease exposure, indicating that wildlife vaccination, along with existing control methods, could be used to eradicate Tb from domestic animals. PMID:19493904

Tompkins, D. M.; Ramsey, D. S. L.; Cross, M. L.; Aldwell, F. E.; de Lisle, G. W.; Buddle, B. M.

2009-01-01

102

Similarity of body size in queens of the wood ant Formica aquilonia from optimal and sub-optimal habitats indicates a strong heritable component.  

PubMed

Body size in animals is affected by both genes and the environment (e.g., the amount of food resources). In ants, body size is related to several traits in an individual's physiology and life history. For example, a large queen may increase offspring production, thus increasing her overall fitness. In this study, whether sub-optimal environmental conditions affect the body size of queens of the red wood ant, Formica aquilonia Yarrow (Hymenoptera: Formicidae). The sizes (head width in mm) of virgin queens, i.e., gynes, originating from forest interiors (resource rich) and from commercial forest clear-cuts (resource poor) were measured. No differences in the body size of the queens from the two habitats were found. In addition, the within-nest variation in queen size was similar between habitat types. The results indicate that the body size variation of F. aquilonia queens is not sensitive to environmental variation, unlike F. aquilonia workers. The lack of environmental variation in queen size in F. aquilonia may be due to a strong selection in the past to monomorphic size in this obligately polygynous (multi-queened) species. PMID:24735372

Haatanen, Marja-Katariina; Sorvari, Jouni

2013-01-01

103

Influences of Wildfire, Habitat Size, and Connectivity on Trout in Headwater Streams Revealed by Patterns of Genetic Diversity  

Microsoft Academic Search

Wildfire is an important natural process in many stream ecosystems, but the ability of fish to respond to wildfire-related disturbances is increasingly constrained by human activities that fragment and degrade stream habitats. In this study, we used molecular genetic markers (nuclear microsatellites) to examine the effects of wildfire and related disturbances along with habitat fragmentation on native rainbow trout in

Helen Neville; Jason Dunham; Amanda Rosenberger; John Umek; Brooke Nelson

2009-01-01

104

Do free-ranging Common brushtail possums (Trichosurus vulpecula) play a role in the transmission of Toxoplasma gondii within a zoo environment?  

Technology Transfer Automated Retrieval System (TEKTRAN)

To investigate the possible role of Common brushtail possums (Trichosurus vulpecula) in the transmission of Toxoplasma gondii within a zoo environment, a serological survey of a free-ranging population resident within Taronga Zoo, Sydney, Australia was undertaken using the modified agglutination tes...

105

Which trees do wild common brushtail possums (Trichosurus vulpecula) prefer? Problems and solutions in scaling laboratory findings to diet selection in the field  

Microsoft Academic Search

In this study, we examined whether a group of plant secondary metabolites - the formylated phloroglucinol compounds (FPCs), which are known to deter feeding on eucalypt foliage by captive marsupial folivores - influence feeding by wild common brushtail possums. There was at least a six-fold range of FPC concentrations in the foliage of individual trees within a single eucalypt species.

Nilla J. Scrivener; Christopher N. Johnson; Ian R. Wallis; Midori Takasaki; William J. Foley; Andrew K. Krockenberger

106

The biology and use of the African brush-tailed porcupine (Atherurus africanus, Gray, 1842)as a food animal. A review  

Microsoft Academic Search

The brush-tailed porcupine (Atherurus africanus) is a hystricomorph rodent, which frequents the forests of West and Central Africa. With an average weight of 3 kg, it is a favourite source of meat for urban and rural populations of Gabon, Nigeria, Cameroon or Congo. Hunted in large quantities, its price is often higher than that of other game or domestic animals.

Ferran Jori; Manel Lopez-béjar; Patrick Houben

1998-01-01

107

Diversity of Cryptosporidium in brush-tailed rock-wallabies (Petrogale penicillata) managed within a species recovery programme.  

PubMed

Host-parasite relationships are likely to be impacted by conservation management practices, potentially increasing the susceptibility of wildlife to emerging disease. Cryptosporidium, a parasitic protozoan genus comprising host-adapted and host-specific species, was used as an indicator of parasite movement between populations of a threatened marsupial, the brush-tailed rock-wallaby (Petrogale penicillata). PCR screening of faecal samples (n?=?324) from seven wallaby populations across New South Wales, identified Cryptosporidium in 7.1% of samples. The sampled populations were characterised as captive, supplemented and wild populations. No significant difference was found in Cryptosporidium detection between each of the three population categories. The positive samples, detected using 18S rRNA screening, were amplified using the actin and gp60 loci. Multi-locus sequence analysis revealed the presence of Cryptosporidium fayeri, a marsupial-specific species, and C.?meleagridis, which has a broad host range, in samples from the three population categories. Cryptosporidium meleagridis has not been previously reported in marsupials and hence the pathogenicity of this species to brush-tailed rock-wallabies is unknown. Based on these findings, we recommend further study into Cryptosporidium in animals undergoing conservation management, as well as surveying wild animals in release areas, to further understand the diversity and epidemiology of this parasite in threatened wildlife. PMID:25834789

Vermeulen, Elke T; Ashworth, Deborah L; Eldridge, Mark D B; Power, Michelle L

2015-08-01

108

Diversity of Cryptosporidium in brush-tailed rock-wallabies (Petrogale penicillata) managed within a species recovery programme  

PubMed Central

Host–parasite relationships are likely to be impacted by conservation management practices, potentially increasing the susceptibility of wildlife to emerging disease. Cryptosporidium, a parasitic protozoan genus comprising host-adapted and host-specific species, was used as an indicator of parasite movement between populations of a threatened marsupial, the brush-tailed rock-wallaby (Petrogale penicillata). PCR screening of faecal samples (n?=?324) from seven wallaby populations across New South Wales, identified Cryptosporidium in 7.1% of samples. The sampled populations were characterised as captive, supplemented and wild populations. No significant difference was found in Cryptosporidium detection between each of the three population categories. The positive samples, detected using 18S rRNA screening, were amplified using the actin and gp60 loci. Multi-locus sequence analysis revealed the presence of Cryptosporidium fayeri, a marsupial-specific species, and C.?meleagridis, which has a broad host range, in samples from the three population categories. Cryptosporidium meleagridis has not been previously reported in marsupials and hence the pathogenicity of this species to brush-tailed rock-wallabies is unknown. Based on these findings, we recommend further study into Cryptosporidium in animals undergoing conservation management, as well as surveying wild animals in release areas, to further understand the diversity and epidemiology of this parasite in threatened wildlife. PMID:25834789

Vermeulen, Elke T.; Ashworth, Deborah L.; Eldridge, Mark D.B.; Power, Michelle L.

2015-01-01

109

Male Kirtland's Warblers’ patch-level response to landscape structure during periods of varying population size and habitat amounts  

Microsoft Academic Search

Forest planners must evaluate how spatiotemporal changes in habitat amount and configuration across the landscape as a result of timber management will affect species’ persistence. However, there are few long-term programs available for evaluation. We investigated the response of male Kirtland's Warbler (Dendroica kirtlandii) to 26 years of changing patch and landscape structure during a large, 26-year forestry-habitat restoration program

Deahn M. Donner; Christine A. Ribic; John R. Probst

2009-01-01

110

Size-related shifts in the habitat associations of young-of-the-year winter flounder (Pseudopleuronectes americanus): field observations and laboratory experiments with sediments and prey.  

PubMed

Field surveys and laboratory studies were used to determine the role of substrata in habitat selection by young-of-the year winter flounder. A synoptic field survey of winter flounder and sediments in the Navesink River-Sandy Hook Bay estuarine system in New Jersey demonstrated that winter flounder distribution was related to sediment grain size. Analysis using a generalized additive model indicated that the probability of capturing 10-49 mm SL winter flounder was high on sediments with a mean grain diameter of size near 1.0 mm. In the laboratory, sediment preferences and the burying ability of winter flounder (15-69 mm SL) were tested by exposing fish in 10-mm size groups to a choice of azoic sediments of different sediment grain sizes. Smaller individuals (<40 mm SL) preferred fine-grained sediments while larger individuals (>/=40 mm SL) preferred coarse-grained sediments. Burying ability increased with size and all flounders avoided sediments that prevented burial. Subsequent laboratory experiments revealed that the presence of live prey (Mya arenaria) can over-ride sediment choice by winter flounder (50-68 mm SL) indicating the complexity of interrelated factors in habitat choice. PMID:11245882

Phelan, B A.; Manderson, J P.; Stoner, A W.; Bejda, A J.

2001-03-15

111

Seed bank size and composition of Betula nana , Vaccinium uliginosum , and Campanula rotundifolia habitats in Svalbard and northern Norway  

Microsoft Academic Search

The rare thermophilous species in the arctic archipelago of Svalbard are probably relicts from previous warmer periods and may be unable to reproduce sexually under the present climatic conditions. Germination of seeds, seed banks, and vegetative sprouts were studied in one Betula nana L., one Vaccinium uliginosum L., and two Cam- panula rotundifolia L. habitats in Svalbard. For comparison, one

Inger Greve Alsos; Sigmund Spjelkavik; Torstein Engelskjøn

2003-01-01

112

Long-Term Habitat Use by Mountain Gorillas ( Gorilla gorilla beringei ). 1. Consistency, Variation, and Home Range Size and Stability  

Microsoft Academic Search

Mountain gorillas are highly folivorous. Food is abundant and perennially available in much of their habitat. Still, limited research has shown that single gorilla groups heavily used areas where food biomass and quality were relatively high and where they met daily nutritional needs with relatively low foraging effort. Also, ecological factors influenced solitary males less than groups with females. Long-term

David P. Watts

1998-01-01

113

The ontogenetic scaling of bite force and head size in loggerhead sea turtles (Caretta caretta): implications for durophagy in neritic, benthic habitats.  

PubMed

Ontogenetic studies of vertebrate feeding performance can help address questions relevant to foraging ecology. Feeding morphology and performance can either limit access to food resources or open up new trophic niches in both aquatic and terrestrial systems. Loggerhead sea turtles are long-lived vertebrates with complex life histories that are marked by an ontogenetic shift from an oceanic habitat to a coastal neritic habitat, and a transition from soft oceanic prey to hard, benthic prey. Although considered durophagous and strong biters, bite performance has not been measured in loggerheads, nor has the ontogeny of bite performance been characterized. In the present study, we collected measurements of bite force in loggerhead turtles from hatchlings to adults. When subadults reach the body size at which the ontogenetic shift occurs, their crushing capability is great enough for them to consume numerous species of hard benthic prey of small sizes. As loggerheads mature and bite performance increases, larger and harder benthic prey become accessible. Loggerhead bite performance eventually surpasses the crushing capability of other durophagous carnivores, thereby potentially reducing competition for hard benthic prey. The increasing bite performance and accompanying changes in morphology of the head and jaws are likely an effective mechanism for resource partitioning and decreasing trophic competition. Simultaneous measurements of body and head size and the use of non-linear reduced major axis regression show that bite force increases with significant positive allometry relative to body size (straight carapace length, straight carapace width and mass) and head size (head width, height and length). Simple correlation showed that all recorded morphometrics were good predictors of measured bite performance, but an AICc-based weighted regression showed that body size (straight carapace width followed by straight carapace length and mass, respectively) were more likely predictors of bite force than head size morphometrics (head width and head length). PMID:22899532

Marshall, Christopher D; Guzman, Alejandra; Narazaki, Tomoko; Sato, Katsufumi; Kane, Emily A; Sterba-Boatwright, Blair D

2012-12-01

114

The diet of introduced brushtail possums Trichosurus vulpecula in a low-diversity New Zealand Nothofagus forest and possible implications for conservation management  

Microsoft Academic Search

We evaluate the diet of introduced brushtail possums Trichosurus vulpecula in a relatively low-diversity New Zealand Nothofagus forest. Although possums only invaded this area 30–40 years ago, densities (0·5–1·0 ha?1) are similar to those recorded for other Nothofagus forests. Thirty-three food types are eaten by possums, but the four most important contribute 68·4% of annual diet. Preference indices show that

Hamish J. Owen; David A. Norton

1995-01-01

115

Chemical characterization of milk oligosaccharides of the common brushtail possum (Trichosurus vulpecula).  

PubMed

Structural characterizations of marsupial milk oligosaccharides have been performed in only three species: the tammar wallaby, the red kangaroo and the koala. To clarify the homology and heterogeneity of milk oligosaccharides among marsupials, 21 oligosaccharides of the milk carbohydrate fraction of the common brushtail possum were characterized in this study. Neutral and acidic oligosaccharides were separated from the carbohydrate fraction of mid-lactation milk and characterized by (1)H-nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The structures of the 7 neutral oligosaccharides were Gal(?1-3)Gal(?1-4)Glc (3'-galactosyllactose), Gal(?1-3)Gal(?1-3)Gal(?1-4)Glc (3", 3'-digalactosyllactose), Gal(?1-3)Gal(?1-3)Gal(?1-3)Gal(?1-4)Glc, Gal(?1-3)Gal(?1-3)Gal(?1-3)Gal(?1-3)Gal(?1-4)Glc, Gal(?1-3)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc (lacto-N-novopentaose I), Gal(?1-3)Gal(?1-3)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc (galactosyl lacto-N-novopentaose I), Gal(?1-3)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-3)Gal(?1-4)Glc (galactosyl lacto-N-novopentaose II). The structures of the 14 acidic oligosaccharides detected were Neu5Ac(?2-3)Gal(?1-3)Gal(?1-4)Glc (sialyl 3'-galactosyllactose), Gal(?1-3)(O-3-sulfate)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc (lacto-N-novopentaose I sulfate a) Gal(?1-3)[Gal(?1-4)(O-3-sulfate)GlcNAc(?1-6)]Gal(?1-4)Glc (lacto-N-novopentaose I sulfate b), Neu5Ac(?2-3)Gal(?1-3)Gal(?1-3)Gal(?1-4)Glc, Neu5Ac(?2-3)Gal(?1-3)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc (sialyl lacto-N-novopentaose a), Gal(?1-3)(-3-O-sulfate)Gal(?1-3)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc, Gal(?1-3)Gal(?1-3)[Gal(?1-4)(-3-O-sulfate)GlcNAc(?1-6)]Gal(?1-4)Glc, Gal(?1-3)[Neu5Ac(?2-6)Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc (sialyl lacto-N-novopentaose b), Neu5Ac(?2-3)Gal(?1-3)Gal(?1-3)Gal(?1-3)Gal(?1-4)Glc, Gal(?1-3)(-3-O-sulphate)Gal(?1-3)Gal(?1-3)Gal(?1-3)Gal(?1-4)Glc, Neu5Ac(?2-3)Gal(?1-3)Gal(?1-3)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc, Gal(?1-3)(-3-O-sulphate)Gal(?1-3)Gal(?1-3)[Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc, Gal(?1-3)Gal(?1-3)Gal(?1-3)[Gal(?1-4)(-3-O-sulphate)GlcNAc(?1-6)]Gal(?1-4)Glc and Gal(?1-3)Gal(?1-3)[Neu5Ac(?2-6)Gal(?1-4)GlcNAc(?1-6)]Gal(?1-4)Glc (galactosyl sialyl lacto-N-novopentaose b). No fucosyl oligosaccharides were detected. Galactosyl lacto-N-novopentaose II, lacto-N-novopentaose I sulfate a, lacto-N-novopentaose I sulfate b and galactosyl sialyl lacto-N-novopentaose b are novel oligosaccharides. The results are compared with those of previous studies on marsupial milk oligosaccharides. PMID:24906475

Urashima, Tadasu; Fujita, Saori; Fukuda, Kenji; Nakamura, Tadashi; Saito, Tadao; Cowan, Phil; Messer, Michael

2014-07-01

116

Vertical Distribution, Size Structure, and Habitat Associations of Four Blenniidae Species on Gas Platforms in the Northcentral Gulf of Mexico  

Microsoft Academic Search

We counted individuals of the family Blenniidae and estimated their sizes on gas platforms southeast of Dauphin Island, Alabama.\\u000a We observed species abundance decreasing as depth increased. Fish sizes also decreased with depth. The most abundant species\\u000a was molly miller, Scartella cristata, followed by plumed blenny, Hypleurochilus multifilis, tessellated blenny, Hypsoblennius invemar, and seaweed blenny, Parablennius marmoreus. Total blenny abundance

Marek F. Topolski; Stephen T. Szedlmayer

2004-01-01

117

The relationship of metals, bifenthrin, physical habitat metrics, grain size, total organic carbon, dissolved oxygen and conductivity to Hyalella sp. abundance in urban California streams.  

PubMed

The objectives of this study were to determine the relationship between Hyalella sp. abundance in four urban California streams and the following parameters: (1) 8 bulk metals (As, Cd, Cr, Cu, Pb, Hg, Ni, and Zn) and their associated sediment Threshold Effect Levels (TELs); (2) bifenthrin sediment concentrations; (3) 10 habitat metrics and total score; (4) grain size (% sand, silt and clay); (5) Total Organic Carbon (TOC); (6) dissolved oxygen; and (7) conductivity. California stream data used for this study were collected from Kirker Creek (2006 and 2007), Pleasant Grove Creek (2006, 2007 and 2008), Salinas streams (2009 and 2010) and Arcade Creek (2009 and 2010). Hyalella abundance in the four California streams generally declined when metals concentrations were elevated beyond the TELs. There was also a statistically significant negative relationship between Hyalella abundance and % silt for these 4 California streams as Hyalella were generally not present in silt areas. No statistically significant relationships were reported between Hyalella abundance and metals concentrations, bifenthrin concentrations, habitat metrics, % sand, % clay, TOC, dissolved oxygen and conductivity. The results from this study highlight the complexity of assessing which factors are responsible for determining the abundance of amphipods, such as Hyalella sp., in the natural environment. PMID:23379940

Hall, Lenwood W; Anderson, Ronald D

2013-01-01

118

QUANTIFYING STRUCTURAL PHYSICAL HABITAT ATTRIBUTES USING LIDAR AND HYPERSPECTRAL IMAGERY  

EPA Science Inventory

Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity and cover, riparian vegetation cover and structure, anthropogenic disturbances and channel-riparian interaction. These habitat attributes will vary dependen...

119

Experimental infections of brush-tailed possums, common wombats and water rats with Leptospira interrogans serovars balcanica and hardjo.  

PubMed

Of 12 brush-tailed possums (Trichosurus vulpecula) inoculated with Leptospira interrogans serovar balcanica 11 developed migroagglutination (MA) antibody to jardjo antigen by 14 days postincubation (PI). Leptospiruria was observed in 2 possums 117 to 145 days PI. Of 6 possums inoculated with serovar hardjo 4 developed low short-lived titres by day 18 PI. Two of 3 wombats (Vombatus ursinus) inoculated with balcanica had high MA titres (greater than or equal to 1:128) by day 16 PI and leptospiruria occurred by day 16. One wombat inoculated with hardjo developed a low MA titre. Low transitory MA titres to hardjo were found in 1 of 3 water rats (Hydromys chrysogaster) after inoculation with balcanica and 1 of 2 given hardjo. Histopathological examination of kidneys revealed mild to moderately severe focal interstitial nephritis in 4 of 8 possums, in 2 wombats and in 2 water rats following experimental infection with balcanica. Similar lesions were observed in 2 of 4 possums, 1 wombat and 2 water rats following experimental infection with hardjo. PMID:533478

Durfee, P T; Presidente, P J

1979-06-01

120

Bill size and dimorphism in tidal-marsh sparrows: island-like processes in a continental habitat.  

PubMed

Conditions favoring population divergence in trophic features, such as the low levels of species richness and interspecific competition found on islands, can be similar to conditions that increase their sexual dimorphism or overall variance. Male emberizid sparrows of tidal marshes have undergone parallel evolution of large bills. We tested for parallel increases between dimorphism and overall variation in bill size by comparing three groups totaling 30 sparrow subspecies: tidal-marsh sparrows, nontidal relatives of tidal-marsh taxa, and representative sparrow taxa. Bill size (and not other features) showed the following patterns in tidal-marsh sparrows compared to nontidal relatives or sparrows at large: (1) an increase; (2) a greater increase in males than females; (3) an increase in sexual dimorphism; and (4) greater variation in females. A high degree of sexual dimorphism in bill size is consistent with the hypothesis that low levels of interspecific and high levels of intraspecific competition select for intraspecific niche divergence. Alternatively, increased sexual selection in tidal-marsh sparrows, vis-a-vis high densities and hence increased male-male competition, may account for the differentially large increase in bill size in males. Relaxed natural selection due to high ecosystem productivity and low interspecific competition may explain why, in tidal-marsh sparrows, female bills have diverged less than males and show higher levels of variability at larger sizes. Both the niche divergence and sexual selection hypotheses depend upon processes, particularly increases in population density, that are similar to those often reported for island passerines. However, the low species diversity and increased intraspecific competition of salt marsh faunas is probably a result of abiotic constraints on colonization (tides and salinity) rather than the isolating distances of island biotas. Thus, both a shift in bill size and increases in its dimorphism and variability may be favored by high productivity and abiotic constraints. PMID:20836464

Greenberg, Russell; Olsen, Brian

2010-08-01

121

Patch occupancy by stone martens Martes foina in fragmented landscapes of central Spain: the role of fragment size, isolation and habitat structure  

NASA Astrophysics Data System (ADS)

We studied the response to forest fragmentation of a generalist carnivore, the stone marten Martes foina, in highly fragmented landscapes of central Spain. Five different areas ( n = 178 fragments) in central Spain were surveyed. This paper analyses the relationship between fragment use by martens (measured through scat presence) and a series of variables related to the size, isolation and vegetation structure of each fragment by means of stepwise logistic regression. Size and isolation have an important effect on stone marten presence in fragments. Our results were similar to those found for other marten species in landscapes with coarse-grain fragmentation, but they contrast with other studies conducted in landscapes with fine-grain fragmentation. These data suggested that in highly fragmented landscapes, size and isolation factors resulting from forest fragmentation were responsible for determining marten responses, irrespective of their habitat generalism. Management policies for the stone marten in highly fragmented scenarios require the maintenance of large forests near continuous forest tracts in mountains or riparian woodlands.

Virgós, Emilio; García, Francisco J.

2002-08-01

122

Preliminary analysis of the habitat characteristics of anchovy and sardine in the Aegean Sea in relation to fish size  

Microsoft Academic Search

The present work examines the size specific distribution of anchovy and sardine in the Aegean Sea (Eastern Mediterranean basin) during early summer. Data from pelagic trawl hauls, multivariate methods, certain satellite environmental data and area topographic characteristics were used in order to identify the parameters that could discriminate the spatial distribution of the juveniles and the adults, of both species.

Tsagarakis Konstantinos; Somarakis Stylianos; Giannoulaki Marianna; A. Machias; V. Valavanis; A. Palialexis; C. Papaconstantinou

2007-01-01

123

Ontogenetic modulation of branch size, shape, and biomechanics produces diversity across habitats in the Bursera simaruba clade of tropical trees.  

PubMed

Organismal size and shape inseparably interact with tissue biomechanical properties. It is therefore essential to understand how size, shape, and biomechanics interact in ontogeny to produce morphological diversity. We estimated within species branch length-diameter allometries and reconstructed the rates of ontogenetic change along the stem in mechanical properties across the simaruba clade in the tropical tree genus Bursera, measuring 376 segments from 97 branches in nine species in neotropical dry to rain forest. In general, species with stiffer materials had longer, thinner branches, which became stiffer more quickly in ontogeny than their counterparts with more flexible materials. We found a trend from short stature and flexible tissues to tall statures and stiff tissues across an environmental gradient of increasing water availability, likely reflecting a water storage-mechanical support tradeoff. Ontogenetic variation in size, shape, and mechanics results in diversity of habits, for example, rapid length extension, sluggish diameter expansion, and flexible tissues results in a liana, as in Bursera instabilis. Even species of similar habit exhibited notable changes in tissue mechanical properties with increasing size, illustrating the inseparable relationship between organismal proportions and their tissue mechanics in the ontogeny and evolution of morphological diversity. PMID:22947317

Rosell, Julieta A; Olson, Mark E; Aguirre-Hernández, Rebeca; Sánchez-Sesma, Francisco J

2012-01-01

124

Population size, distribution and habitat selection of the white-tailed eagle Haliaeetus albicilla in the alluvial wetlands of Croatia  

Microsoft Academic Search

From 2003–2006, research on the breeding distribution of the white-tailed eagle (Haliaeetus albicilla) was conducted in Croatia in order to assess the size of the national population. In 125 locations, clear signs of breeding\\u000a activity were found. An additional 10 presumably active territories were detected but it was not possible to locate the exact\\u000a position of the nests and confirm

Andreja Radovi?; Tibor Mikuska

2009-01-01

125

Adaptive divergence in body size overrides the effects of plasticity across natural habitats in the brown trout.  

PubMed

The evolution of life-history traits is characterized by trade-offs between different selection pressures, as well as plasticity across environmental conditions. Yet, studies on local adaptation are often performed under artificial conditions, leaving two issues unexplored: (i) how consistent are laboratory inferred local adaptations under natural conditions and (ii) how much phenotypic variation is attributed to phenotypic plasticity and to adaptive evolution, respectively, across environmental conditions? We reared fish from six locally adapted (domesticated and wild) populations of anadromous brown trout (Salmo trutta) in one semi-natural and three natural streams and recorded a key life-history trait (body size at the end of first growth season). We found that population-specific reaction norms were close to parallel across different streams and Q ST was similar - and larger than F ST - within all streams, indicating a consistency of local adaptation in body size across natural environments. The amount of variation explained by population origin exceeded the variation across stream environments, indicating that genetic effects derived from adaptive processes have a stronger effect on phenotypic variation than plasticity induced by environmental conditions. These results suggest that plasticity does not "swamp" the phenotypic variation, and that selection may thus be efficient in generating genetic change. PMID:23919140

Rogell, Björn; Dannewitz, Johan; Palm, Stefan; Dahl, Jonas; Petersson, Erik; Laurila, Anssi

2013-07-01

126

Soil aggregates as habitats for different microbial functional communities: Impact of different aggregate sizes and land-use  

NASA Astrophysics Data System (ADS)

Soil is a complex environment containing a huge diversity of microhabitats. This diversity of microhabitats can be taken into consideration when studying soil microbial communities by investigating soil aggregates as specific soil compartments. However, there is still an intense debate about the potential role of soil aggregates in structuring microbial communities. Thus, the aim of this study was to investigate the geochemical conditions and abundance of microbial communities among soil aggregates. Four different field sites with contrasting land-use (e.g. grassland, cropland, forest) were sampled from Critical Zone Observatory Fuchsenbigl/Marchfeld near Vienna (Austria). Aggregates of six different size classes were obtained by dry-sieving (0-0.25, 0.25-0.5, 0.5-1.0, 1-2, 2-5, 5-10 mm), and characterized geochemically. Quantitative-PCR (Q-PCR) was used to investigate the abundance of bacteria, archaea and fungi, and indicator genes for functional guilds like N-fixation, denitrification, metal reduction, sulphate reduction, and methanogenesis. The Q-PCR results showed that different land-use had significantly different abundances for all the genes, with the cropland site showing the lowest abundance for most of the genes. In contrast, fewer differences were found in gene abundance between the different sizes of soil aggregates, with no specific trends across all the genes, but significant differences related to individual genes and land-use.

van der Zaan, Bas; Blaud, Aimeric; Lair, Georg; Menon, Manoj; Zhang, Dayi; Blum, Winfried; Huang, Wei; van Gaans, Pauline; Banwart, Steve

2014-05-01

127

Host size- and habitat-dependent intensity of Heliconema longissimum (Nematoda: Physalopteridae) in the Japanese eel (Anguilla japonica).  

PubMed

Heliconema longissimum (Ortlepp, 1923) is an ecologically poorly known nematode found in the stomach of Japanese eels, Anguilla japonica Temminck and Schlegel. The occurrence of this nematode in Japanese eels was surveyed in 2 contiguous brackish-water areas (Misho Cove and the lower Renjoji River) of Ehime Prefecture, western Japan, during April 2008 to March 2009. The factors associated with the nematode intensity were also assessed by applying generalized additive models (GAM). Heliconema longissimum exhibited nearly 100% prevalence in both areas, but its intensity differed. The heavier infection in the cove eels indicates that H. longissimum is mainly distributed in the cove, which supports the past speculation for this nematode as a brackish-water parasite. The intensity also increased with the body size of eels. This tendency suggests that the eels inhabiting the cove consume, as they grow, a greater quantity of crustaceans that presumably serve as the nematode's intermediate hosts. PMID:21671717

Katahira, Hirotaka; Mizuno, Kouki; Nagasawa, Kazuya

2011-12-01

128

A quantitative study of the morphological development and bacterial colonisation of the gut of the tammar wallaby Macropus eugenii eugenii and brushtail possum Trichosurus vulpecula during in-pouch development  

Microsoft Academic Search

We compared the rates of change of various morphological parameters of the stomach, small intestine, caecum and colon of tammar wallabies and brushtail possums with body mass during in-pouch development. These were correlated with changes in the numbers of bacterial species in the various gut segments. In the pouch-young of both species, the wet tissue masses of all gut segments

R. G. Lentle; D. Dey; C. Hulls; D. J. Mellor; P. J. Moughan; K. J. Stafford; K. Nicholas

2006-01-01

129

Partitioning of Habitat and Prey by Abundant and Similar-sized Species of the Triglidae and Pempherididae (Teleostei) in coastal waters  

NASA Astrophysics Data System (ADS)

The aim of this study was to determine whether certain co-occurring and abundant species of the teleost families Triglidae and Pempherididae are segregated spatially and/or by diet, and are thus less likely to be susceptible to competition for resources. Nocturnal otter trawling in shallow (5-15 m) and deeper (20-35 m) waters in four regions along ˜200 km of the south-western Australian coastline collected large numbers of a wide size range of the triglids Lepidotrigla modestaand Lepidotrigla papilioand the pempheridids Pempheris klunzingeriand Parapriacanthus elongatus. Although these four species frequently co-occurred at several sites, each species attained its highest density at different sites, thereby representing a partial segregation of these species by habitat. This even occurred with the congeneric triglid species, with L. modestabeing most abundant in the four deep, offshore sites, while L. papiliowas most numerous at three sites which varied in depth and distance from shore. Although triglids and pempheridids both consumed substantial amounts of amphipods and mysids, only the members of the latter family ingested a large amount of errant polychaetes. The latter difference is assumed to reflect the fact that, in comparison with triglids, pempheridids can swim faster, have a mouth adapted for feeding upwards in the water column and feed at night when errant polychaetes emerge from the substratum. Although the dietary compositions of L. modestaand L. papiliodid not differ significantly when analyses were based on dietary data for all sites, they did differ significantly when analyses were restricted to dietary data obtained when both species were abundant and co-occurred. The likelihood of competition for food is thus reduced in the latter circumstances. In comparison with P. klunzingeri, P. elongatusconsumed a relatively larger volume of amphipods and a relatively smaller volume of mysids, which are more mobile, implying that P. elongatusfeeds to a greater extent on rather than above the substratum surface. The diets of all species underwent ontogenetic changes, which were particularly marked in P. klunzingeriwhere an increase in body size was accompanied by a reduced consumption of mysids and an increased ingestion of errant polychaetes and amphipods. The fact that L. modesta, L. papilio, P. klunzingeriand P. elongatusare partially segregated by habitat and feed on suites of prey which differ in composition, allied with an interfamilial difference in the time of feeding, would reduce the likelihood of competition for resources amongst these four species, when they co-occur and are abundant. Furthermore, ontogenetic changes in diet would reduce the potential for intraspecific competition for food.

Platell, M. E.; Potter, I. C.

1999-02-01

130

Aquatic Habitats  

NSDL National Science Digital Library

The site offers information on Australia's aquatic habitats and their protection, management, and rehabilitation. Visitors will also find instructions for reporting fish kills and information on how to help protect and conserve fish habitats.

131

Intramural neural pathways between the duodenum and sphincter of Oddi in the Australian brush-tailed possum in vivo.  

PubMed Central

1. Balloon distension of the duodenum 2 cm oral or anal to the sphincter of Oddi-duodenal junction elevated the amplitude of spontaneous sphincter of Oddi phasic contractions by 37.7 +/- 8.5 or 120.1 +/- 79.8%, respectively (mean +/- S.E.M., both n = 6, P < 0.05, Wilcoxon test). To further investigate this response, this study aimed to determine if: (i) electrical field stimulation (EFS) of the duodenum influences sphincter of Oddi activity; (ii) intramural nerves mediate the response; and (iii) nicotinic and/or muscarinic receptors are involved. 2. Electrical field stimulation (70 V, 0.5 ms; 5-60 Hz, 10-20 s) of the duodenal anterior serosal surface 2-4 cm oral or anal to the sphincter of Oddi-duodenal junction, produced excitatory responses in the sphincter of Oddi in anaesthetized Australian brush-tailed possums (n = 45). 3. These responses were frequency dependent, maximal at 30 Hz (n = 4) and abolished by tetrodotoxin (9 micrograms kg-1 I.A.; n = 6), or by crushing the duodenum (n = 3). Hexamethonium bromide (30 mg kg-1 I.V.) did not significantly alter the response to duodenal EFS either oral (n = 6) or anal (n = 8) to the sphincter of Oddi-duodenal junction. Atropine sulphate (30 micrograms kg-1 I.V.) reduced the response to duodenal EFS oral and anal to the sphincter of Oddi-duodenal junction to 11.2 +/- 5.8 (n = 6) and 45.0 +/- 26.8% (n = 8), respectively (both P < 0.05). 4. Bilateral cervical vagotomy and guanethidine infusion (10 mg kg-1 over 15 min I.V.) did not significantly alter the responses to duodenal EFS (n = 7). 5. Excitatory intramural neural pathways between the sphincter of Oddi and the segment of duodenum 4 cm oral and anal to the sphincter of Oddi-duodenal junction have been demonstrated. These postganglionic pathways may involve muscarinic receptors. PMID:7738836

Saccone, G T; Harvey, J R; Baker, R A; Toouli, J

1994-01-01

132

In vitro hepatic microsomal metabolism of meloxicam in koalas (Phascolarctos cinereus), brushtail possums (Trichosurus vulpecula), ringtail possums (Pseudocheirus peregrinus), rats (Rattus norvegicus) and dogs (Canis lupus familiaris).  

PubMed

Quantitative and qualitative aspects of in vitro metabolism of the non-steroidal anti-inflammatory drug meloxicam, mediated via hepatic microsomes of specialized foliage (Eucalyptus) eating marsupials (koalas and ringtail possums), a generalized foliage eating marsupial (brushtail possum), rats, and dogs, are described. Using a substrate depletion method, intrinsic hepatic clearance (in vitro Clint) was determined. Significantly, rates of oxidative transformation of meloxicam, likely mediated via cytochromes P450 (CYP), were higher in marsupials compared to rats or dogs. The rank order of apparent in vitro Clint was brushtail possums (n=3) (mean: 394?L/min/mg protein), >koalas (n=6) (50), >ringtail possums (n=2) (36) (with no significant difference between koalas and ringtail possums), >pooled rats (3.2)>pooled dogs (in which the rate of depletion, as calculated by the ratio of the substrate remaining was <20% and too slow to determine). During the depletion of meloxicam, at a first-order rate constant, 5-hydroxymethyl metabolite (M1) was identified in the brushtail possums and the rat as the major metabolite. However, multiple hydroxyl metabolites were observed in the koala (M1, M2, and M3) and the ringtail possum (M1 and M3) indicating that these specialized foliage-eating marsupials have diverse oxidation capacity to metabolize meloxicam. Using a well-stirred model, the apparent in vitro Clint of meloxicam for koalas and the rat was further scaled to compare with published in vivo Cl. The closest in vivo Cl prediction from in vitro data of koalas was demonstrated with scaled hepatic Cl(total) (average fold error=1.9) excluding unbound fractions in the blood and microsome values; whereas for rats, the in-vitro scaled hepatic Cl fu(blood, mic), corrected with unbound fractions in the blood and microsome values, provided the best prediction (fold error=1.86). This study indicates that eutherians such as rats or dogs serve as inadequate models for dosage extrapolation of this drug to marsupials due to differences in hepatic turnover rate. Furthermore, as in vivo Cl is one of the pharmacokinetic indexes for determining therapeutic drug dosages, this study demonstrates the utility of in vitro to in vivo scaling as an alternative prediction method of drug Cl in koalas. PMID:24345479

Kimble, B; Li, K M; Valtchev, P; Higgins, D P; Krockenberger, M B; Govendir, M

2014-04-01

133

Ontogenetic Habitat Shifts of Juvenile Bear Lake Sculpin  

Microsoft Academic Search

Bear lake sculpin Cottus extensus exhibit ontogenetic habitat shifts during their initial year of life. Distribution and habitat switching was measured with bimonthly bottom-trawl surveys repeated throughout the summer. Patterns of daily growth increments on otoliths were used to measure the history of habitat residence, individual size at the time of the habitat switch, and habitat-specific growth rates. Laboratory experiments

James R. Ruzycki; Wayne A. Wurtsbaugh

1999-01-01

134

Exploring Habitats!  

NSDL National Science Digital Library

If you could live anywhere in the world, where would you live? Do you think you could survive anywhere in the world or in any habitat? What types of adaptations might help you survive in your dream habitat? Many places seem great to visit, but you won't know if it's the place for you unless you know the characteristics of the habitat. This lesson will encourage your students to research habitats and adaptations that allow plants and animals to survive in their natural environments.

Vanessa Brewster

2012-06-14

135

Habitat Mapping  

NSDL National Science Digital Library

How do we study what we cannot see or touch? Students learn about technologies used for underwater mapping, such as benthic habitat images produced by GIS. They participate in a class discussion on why habitat mapping is useful and how current technology works to make bathymetry mapping possible. Through inquiry-based questions, students brainstorm about the importance of bathymetry mapping to help us explore and map the seafloor, marine habitats and the water column. They examine collected data and draw conclusions. Students learn how remote sensing and underwater vehicles designed by engineers give scientists more data to be able to better map marine habitats.

Engineering K-PhD Program,

136

To what extent are the dietary compositions of three abundant, co-occurring labrid species different and related to latitude, habitat, body size and season?  

PubMed

This study demonstrated that the dietary composition of each of three abundant reef-associated labrid species in temperate Western Australia differed significantly with latitude and changed with increasing body size and almost invariably differed among those species when they co-occurred. These results were derived from comparisons and multivariate analyses of volumetric dietary data, obtained from the foregut contents of Coris auricularis, Notolabrus parilus and Ophthalmolepis lineolatus from the Jurien Bay Marine Park (JBMP) and waters off Perth, 250 km to the south. Latitudinal differences in the dietary compositions of each species in exposed reefs typically reflected greater contributions by large crustaceans, bivalve molluscs, echinoids and annelids to the diets in the waters off Perth than in the JBMP, whereas the reverse was true for gastropods and small crustaceans. The diet of each species exhibited similar, but not identical, quantitative changes with increasing body size, with the contributions of small crustaceans declining and those of large crustaceans and echinoids increasing, while that of gastropods underwent little change. Within the JBMP, the dietary compositions of both C. auricularis and N. parilus were similar in exposed and sheltered reefs and the same was true for N. parilus in the sheltered reefs and interspersed areas of seagrass. The latter similarity demonstrated that, in both of those divergent habitat types, N. parilus feeds on prey associated with either the sand or the macrophytes that cover and lie between the reefs. Although the main dietary components of each species were the same, i.e. gastropods, small crustaceans (mainly amphipods and isopods), large crustaceans (particularly penaeids and brachyuran crabs) and echinoids, their contributions varied among those species, which accounts for the significant interspecific differences in diet. Coris auricularis had the most distinct diet, due mainly to an ingestion of greater volumes of small crustaceans, e.g. amphipods and isopods, and lesser volumes of large crustaceans, e.g. brachyuran crabs, which was associated with a relatively narrower mouth and smaller teeth and the absence of prominent canines at the rear of the jaw. The above intra and interspecific differences in dietary composition would reduce, on the south-west coast of Australia, the potential for competition for food among and within these three abundant labrids, each of which belongs to different genera within the Julidine clade. PMID:21651541

Lek, E; Fairclough, D V; Platell, M E; Clarke, K R; Tweedley, J R; Potter, I C

2011-06-01

137

Habitat automation  

NASA Technical Reports Server (NTRS)

A habitat, on either the surface of the Moon or Mars, will be designed and built with the proven technologies of that day. These technologies will be mature and readily available to the habitat designer. We believe an acceleration of the normal pace of automation would allow a habitat to be safer and more easily maintained than would be the case otherwise. This document examines the operation of a habitat and describes elements of that operation which may benefit from an increased use of automation. Research topics within the automation realm are then defined and discussed with respect to the role they can have in the design of the habitat. Problems associated with the integration of advanced technologies into real-world projects at NASA are also addressed.

Swab, Rodney E.

1992-01-01

138

WILDLIFE HABITAT RELATIONS AND HABITAT FRAGMENTATION  

E-print Network

WILDLIFE HABITAT RELATIONS AND HABITAT FRAGMENTATION IV #12;#12;353USDA Forest Service Gen. Tech. Rep. PSW-GTR-160. 1997. Section Overview Wildlife Habitat Relations and Habitat Fragmentation section on wildlife habitat relations and habitat fragmentation in hardwood rangelands from this symposium

Standiford, Richard B.

139

Hyperlink Habitats  

NSDL National Science Digital Library

This activity is designed to help students understand the complexity of nature by utilizing an online illustration of the ways in which various elements of a rainforest ecosystem are interconnected. Students will map the online habitat and create their own hyperlink habitat, either in print or on the Web, for a local ecosystem. When they are finished, they can submit their work to the Discovery Channel School.

140

Combining Site Occupancy, Breeding Population Sizes and Reproductive Success to Calculate Time-Averaged Reproductive Output of Different Habitat Types: An Application to Tricolored Blackbirds  

PubMed Central

In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005–2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we employ should be useful in other metapopulation studies for calculating time-averaged reproductive output for different sites. PMID:24817307

Holyoak, Marcel; Meese, Robert J.; Graves, Emily E.

2014-01-01

141

Combining site occupancy, breeding population sizes and reproductive success to calculate time-averaged reproductive output of different habitat types: an application to Tricolored Blackbirds.  

PubMed

In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005-2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we employ should be useful in other metapopulation studies for calculating time-averaged reproductive output for different sites. PMID:24817307

Holyoak, Marcel; Meese, Robert J; Graves, Emily E

2014-01-01

142

Hatching phenology, life history and egg bank size of fairy shrimp Branchipodopsis spp. (Branchiopoda, Crustacea) in relation to the ephemerality of their rock pool habitat  

Microsoft Academic Search

In temporary aquatic habitats, permanence and the severe disturbance associated with desiccation are strong selective agents\\u000a expected to lead to differentiation in life history strategies in populations experiencing different disturbance regimes.\\u000a Besides optimal timing of hatching of dormant life stages, maturation and reproduction, pool inhabitants also benefit from\\u000a the acquisition of reliable cues for the quality of the ambient environment.

Bram Vanschoenwinkel; Maitland Seaman; Luc Brendonck

2010-01-01

143

Isotopic shifts with size, culture habitat, and enrichment between the diet and tissues of the Japanese scallop Mizuhopecten yessoensis (Jay, 1857)  

Microsoft Academic Search

Use of stable isotope signatures to trace diet patterns in cultured marine bivalves, particularly when changing culture habitat,\\u000a requires knowledge of the isotopic shift and enrichment between diet and consumer’s tissues. The aim of this study was to\\u000a determine the patterns of isotope change and the variability of enrichment values (??13C and ??15N) in different tissues (muscle, gonad, digestive gland)

Frolan A. Aya; Isao Kudo

2010-01-01

144

Essential Fish Habitat and Critical Habitat  

E-print Network

Essential Fish Habitat and Critical Habitat: A comparison NOAA National Marine Fisheries Service #12;Essential fish habitat (EFH) is identified for species managed in Fishery Management Plans under the Magnuson-Stevens Fishery Conservation and Management Act. Essential fish habitat is the habitat necessary

145

Habitat Design Optimization and Analysis  

NASA Technical Reports Server (NTRS)

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.

SanSoucie, Michael P.; Hull, Patrick V.; Tinker, Michael L.

2006-01-01

146

Habitat Observations  

NSDL National Science Digital Library

In this outdoor activity, learners discover the wonders of the habitat surrounding them. After reading "The Empty Lot," a picture book by Dale Fife, learners observe and record in writing what happens in the natural environment around them. Spending time outdoors observing nature can help learners better understand and appreciate the world in which we live.

2012-06-26

147

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

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

148

Assessing the Effectiveness of Tuberculosis Management in Brushtail Possums (Trichosurus vulpecula), through Indirect Surveillance of Mycobacterium bovis Infection Using Released Sentinel Pigs  

PubMed Central

In New Zealand, wild pigs acquire Mycobacterium bovis infection by scavenging tuberculous carrion, primarily carcasses of the main disease maintenance host, the brushtail possum (Trichosurus vulpecula). We investigated the utility of captive-reared, purpose-released pigs as sentinels for tuberculosis (TB) following lethal possum control and subsequent population recovery. Within 2-3 years of possum control by intensive poisoning, TB prevalence and the incidence rate of M. bovis infection in released sentinel pigs were lower than in an adjacent area where possums had not been poisoned. Unexpectedly, TB did not decline to near zero levels among pigs in the poisoned area, a fact which reflected an unanticipated rapid increase in the apparent abundance of possums. Monitoring infection levels among resident wild pigs confirmed that TB prevalence, while reduced due to possum control, persisted in the poisoned area at >20% among pigs born 2-3 years after poisoning, while remaining >60% among resident wild pigs in the nonpoisoned area. When fitted with radio-tracking devices, purpose-released pigs provided precise spatial TB surveillance information and facilitated effective killing of wild pigs when employed as “Judas” animals to help locate residents. Sentinel pigs offer value for monitoring disease trends in New Zealand, as TB levels in possums decline nationally due to large-scale possum control. PMID:24804148

Nugent, G.; Yockney, I. J.; Whitford, E. J.; Cross, M. L.

2014-01-01

149

Significance of sulfhydryl compounds in the manifestation of fluoroacetate toxicity to the rat, brush-tailed possum, woylie and western grey kangaroo.  

PubMed

Levels of citrate in kidneys and livers of rats with normal glutathione levels increased 6.8 and 1.7-fold respectively 2 h after dosing with 1.5 mg of compound 1080 (= 95% sodium fluoroacetate) per kilogram body weight. In animals with liver glutathione levels 15% of normal, increases in plasma and liver citrate levels after dosing with fluoroacetate were significantly greater than those of control animals. Cysteamine and N-acetylcysteine, like glutathione, partially protected aconitate hydratase from fluorocitrate inhibition in rat liver preparations but were unable to replace glutathione as a substrate for the defluorination of fluoroacetate in vitro. N-Acetylcysteine did not diminish plasma citrate levels of glutathione-deficient rats dosed with fluoroacetate, while cysteamine inhibited the rate of in vivo defluorination in glutathione-deficient brush-tailed possums. It is suggested that non-physiological sulfhydryl compounds are ineffective antidotes to fluoroacetate intoxication in vivo. The in vivo defluorination patterns of four mammal species with differing sensitivities to fluoroacetate did not indicate a direct relationship between tolerance and rate of defluorination and it is also suggested that a high level of activity of the glutathione-S-transferase responsible for the defluorination of fluoroacetate is not the major mechanism for circumventing fluoroacetate toxicity in resistant mammals. PMID:4051904

Mead, R J; Moulden, D L; Twigg, L E

1985-01-01

150

Variations in epithelial Na+ transport and epithelial sodium channel localisation in the vaginal cul-de-sac of the brushtail possum, Trichosurus vulpecula, during the oestrous cycle.  

PubMed

The fluid in the vaginal cul-de-sac of the brushtail possum, Trichosurus vulpecula, is copious at ovulation when it may be involved in sperm transport or maturation, but is rapidly reabsorbed following ovulation. We have used the Ussing short-circuit current (Isc) technique and measurements of transcript and protein expression of the epithelial Na+ channel (ENaC) to determine if variations in electrogenic Na+ transport are associated with this fluid absorption. Spontaneous Isc (-2 during anoestrus, 60-80µAcm-2 in cycling animals) was inhibited by serosal ouabain. Mucosal amiloride (10µmolL-1), an inhibitor of ENaC, had little effect on follicular Isc but reduced luteal Isc by ~35%. This amiloride-sensitive Isc was dependent on mucosal Na+ and the half-maximal inhibitory concentration (IC50)-amiloride (0.95?molL-1) was consistent with ENaC-mediated Na+ absorption. Results from polymerase chain reaction with reverse transcription (RT-PCR) indicate that ?ENaC mRNA is expressed in anoestrous, follicular and luteal phases. However, in follicular animals ?ENaC immunoreactivity in epithelial cells was distributed throughout the cytoplasm, whereas immunoreactivity was restricted to the apical pole of cells from luteal animals. These data suggest that increased Na+ absorption contributes to fluid absorption during the luteal phase and is regulated by insertion of ENaC into the apical membrane of cul-de-sac epithelial cells. PMID:25056576

Alsop, T-A; McLeod, B J; Butt, A G

2014-07-24

151

Characterization of flow and mixing regimes within the ileum of the brushtail possum using residence time distribution analysis with simultaneous spatio-temporal mapping.  

PubMed

We studied the flow and mixing regimes in isolated segments of the terminal ileum of brushtail possums during spontaneous circumferential and longitudinal contractions under conditions that allowed backflow and compared them with those of inactive segments. Residence time distributions (RTDs) were determined by perfusion with two probes of different rheological properties to which an inert dye marker was added. Ileal segment volume and oscillatory flow during the period of RTD determination were derived from spatiotemporal maps. High viscosity guar gum solution generated RTDs characteristic of laminar flow in inactive ileal segments which confirmed that no slip was occurring at the mucosal layer. In active segments, motility and consequent oscillatory flow imparted significant additional axial dispersion to the flow patterns of both probes. Mixing occurred episodically during periods when intestinal volume was reduced and onflow was augmented by peristalsis, which may prevent the establishment of steady state conditions. Marker concentration rose more steeply when active ileal segments were being perfused with a probe of similar viscosity to normal digesta than with low viscosity Earle's/Hepes solution, each being subject to similar levels of oscillatory flow. This indicated that a coarser mixing regime prevailed and that absorption of nutrients from viscous digesta would rely to a greater degree on molecular diffusion. PMID:17495038

Janssen, P W M; Lentle, R G; Asvarujanon, P; Chambers, P; Stafford, K J; Hemar, Y

2007-08-01

152

Male-Biased Predation and Its Effect on Paternity Skew and Life History in a Population of Common Brushtail Possums (Trichosurus vulpecula)  

PubMed Central

Differences in predation risk may exert strong selective pressures on life history strategies of populations. We investigated the potential for predation to shape male mating strategies in an arboreal folivore, the common brushtail possum (Trichosurus vulpecula Kerr). We predicted that possums in a tropical population exposed to high natural levels of predation would grow faster and reproduce earlier compared to those in temperate populations with lower predation. We trapped a population of possums in eucalypt woodland in northern Australia each month to measure life history traits and used microsatellites to genotype all individuals and assign paternity to all offspring. We observed very high levels of male-biased predation, with almost 60% of marked male possums being eaten by pythons, presumably as a result of their greater mobility due to mate-searching. Male reproductive success was also highly skewed, with younger, larger males fathering significantly more offspring. This result contrasts with previous studies of temperate populations experiencing low levels of predation, where older males were larger and the most reproductively successful. Our results suggest that in populations exposed to high levels of predation, male possums invest in increased growth earlier in life, in order to maximise their mating potential. This strategy is feasible because predation limits competition from older males and means that delaying reproduction carries a risk of failing to reproduce at all. Our results show that life histories are variable traits that can match regional predation environments in mammal species with widespread distributions. PMID:25372294

DeGabriel, Jane L.; Moore, Ben D.; Foley, William J.; Johnson, Christopher N.

2014-01-01

153

Influence of primary prey on home-range size and habitat-use patterns of northern spotted owls ( Strix occidentalis caurina )  

Microsoft Academic Search

433 Abstract: Correlations between the home-range size of northern spotted owls (Strix occidentalis caurina) and proportion of their range in old-growth forest have been reported, but there are few data on the relationship between their home-range size and prey. The primary prey of spotted owls are wood rats and northern flying squirrels (Glaucomys sabrinus). Wood rats are larger and heavier

Cynthia J. Zabel; Kevin McKelvey; James P. Ward Jr.

1995-01-01

154

Urban Habitats  

NSDL National Science Digital Library

_Urban Habitats_, published by the Center for Urban Restoration Ecology (CURE), is "a peer-reviewed, fully indexed scientific journal written and edited for a wide audience of researchers, restoration ecologists, park and preserve managers, government officials, and naturalists." The premier issue of this e-journal (focused on urban flora worldwide) is available online, and researchers are encouraged to submit articles and multimedia resources for future issues (detailed submission guidelines provided). CURE is a joint project of Rutgers University and the Brooklyn Botanic Garden.

155

Biodiversity in urban habitat patches.  

PubMed

We examined the biodiversity of urban habitats in Birmingham (England) using a combination of field surveys of plants and carabid beetles, genetic studies of four species of butterflies, modelling the anthropochorous nature of the floral communities and spatially explicit modelling of selected mammal species. The aim of the project was to: (i) understand the ecological characteristics of the biota of cities model, (ii) examine the effects of habitat fragment size and connectivity upon the ecological diversity and individual species distributions, (iii) predict biodiversity in cities, and (iv) analyse the extent to which the flora and fauna utilise the 'urban greenways' both as wildlife corridors and as habitats in their own right. The results suggest that cities provide habitats for rich and diverse range of plants and animals, which occur sometimes in unlikely recombinant communities. The studies on carabids and butterflies illustrated the relative importance of habitat quality on individual sites as opposed to site location within the conurbation. This suggests that dispersal for most of our urban species is not a limiting factor in population persistence, although elements of the woodland carabid fauna did appear to have some geographical structuring. Theoretical models suggested that dormice and water voles may depend on linear habitats for dispersal. The models also indicated that other groups, such as small and medium sized mammals, may use corridors, although field-based research did not provide any evidence to suggest that plants or invertebrates use urban greenways for dispersal. This finding indicates the importance of identifying a target species or group of species for urban greenways intended as dispersal routeways rather than as habitat in their own right. Their importance for most groups is rather that greenways provide a chain of different habitats permeating the urban environment. We suggest that planners can have a positive impact on urban biodiversity by slowing the pace of redevelopment and by not hurrying to tidy up and redevelop brownfield sites. PMID:16297440

Angold, P G; Sadler, J P; Hill, M O; Pullin, A; Rushton, S; Austin, K; Small, E; Wood, B; Wadsworth, R; Sanderson, R; Thompson, K

2006-05-01

156

Temporal and spatial dynamics of trypanosomes infecting the brush-tailed bettong (Bettongia penicillata): a cautionary note of disease-induced population decline  

PubMed Central

Background The brush-tailed bettong or woylie (Bettongia penicillata) is on the brink of extinction. Its numbers have declined by 90% since 1999, with their current distribution occupying less than 1% of their former Australian range. Woylies are known to be infected with three different trypanosomes (Trypanosoma vegrandis, Trypanosoma copemani and Trypanosoma sp. H25) and two different strains of T. copemani that vary in virulence. However, the role that these haemoparasites have played during the recent decline of their host is unclear and is part of ongoing investigation. Methods Woylies were sampled from five locations in southern Western Australia, including two neighbouring indigenous populations, two enclosed (fenced) populations and a captive colony. PCR was used to individually identify the three different trypanosomes from blood and tissues of the host, and to investigate the temporal and spatial dynamics of trypanosome infections. Results The spatial pattern of trypanosome infection varied among the five study sites, with a greater proportion of woylies from the Perup indigenous population being infected with T. copemani than from the neighbouring Kingston indigenous population. For an established infection, T. copemani detection was temporally inconsistent. The more virulent strain of T. copemani appeared to regress at a faster rate than the less virulent strain, with the infection possibly transitioning from the acute to chronic phase. Interspecific competition may also exist between T. copemani and T. vegrandis, where an existing T. vegrandis infection may moderate the sequential establishment of the more virulent T. copemani. Conclusion In this study, we provide a possible temporal connection implicating T. copemani as the disease agent linked with the recent decline of the Kingston indigenous woylie population within the Upper Warren region of Western Australia. The chronic association of trypanosomes with the internal organs of its host may be potentially pathogenic and adversely affect their long term fitness and coordination, making the woylie more susceptible to predation. PMID:24708757

2014-01-01

157

Seasonal changes in RFamide-related peptide-3 neurons in the hypothalamus of a seasonally breeding marsupial species, the brushtail possum (Trichosurus vulpecula).  

PubMed

RFamide-related peptide-3 (RFRP-3) neurons have been shown to inhibit gonadotropin-releasing hormone (GnRH) neuronal activity and hence reproduction in birds and eutherian mammals. They have also been proposed to have a direct hypophysiotropic effect on pituitary gonadotropin release. We used a new RFRP-3 antibody to characterize the cell body distribution and fiber projections of RFRP-3 neurons in the adult female brushtail possum brain. RFRP-3-immunoreactive cell bodies were found scattered within the dorsomedial hypothalamus and the dorsomedial half of the ventromedial hypothalamus, while GnRH neurons were observed scattered rostrocaudally along the lateral septum, rostral to the medial septum. There was a significant 2-fold increase in the RFRP-3 cell body number during the nonbreeding season (summer) compared to the breeding season (winter). Immunoreactive RFRP-3 fibers were distributed throughout the thalamus, preoptic area, and hypothalamus. Very few fibers were observed in the median eminence, especially in the external zone. Intraperitoneal injection of the retrograde tracer Fluoro-Gold resulted in the labeling of 40% of hypophysiotropic tuberoinfundibular dopaminergic (tyrosine hydroxylase-positive) neurons; however, <10% of zona incerta dopaminergic neurons (which are not hypophysiotropic) or RFRP-3 neurons were labeled with this tracer. These observations suggest that RFRP-3 exhibits a seasonal fluctuation in cell numbers, as seen in sheep and birds, which is consistent with an increased inhibitory tone during the nonbreeding season. The lack of RFRP-3 fibers in the median eminence and of Fluoro-Gold uptake from the periphery imply that the actions of this peptide occur primarily centrally rather than at the anterior pituitary gland. PMID:23504980

Harbid, Anan A; McLeod, Bernie J; Caraty, Alain; Anderson, Greg M

2013-09-01

158

The spatial ecology of Eastern Hognose Snakes (Heterodon platirhinos): habitat selection, home range size, and the effect of roads on movement  

E-print Network

edits came back to me quicker than the speed of light and often before a (much needed) night's sleep range size, and the effect of roads on movement patterns Laura Elizabeth Robson Thesis management and recovery. I conducted a radiotelemetry study to examine the spatial ecology and the effects

Blouin-Demers, Gabriel

159

How Human Household Size Affects the Habitat of Black-and-White Snub-Nosed Monkeys ( Rhinopithecus bieti ) in Hongla Snow Mountain Nature Reserve in Tibet, China  

Microsoft Academic Search

Human impacts on the environment at local or regional scales largely depend on intrinsic characteristics of the population,\\u000a such as household size, household number, and human population growth. These demographic factors can vary considerably among\\u000a ethnic groups sharing similar ecological landscapes, yet the role of traditional cultural practices in shaping local environmental\\u000a impacts is not well known for many parts

Rui-Chang Quan; Yong Huang; Matthew W. Warren; Qi-Kun Zhao; Guopeng Ren; Sheng Huo; Yongcheng Long; Jianguo Zhu

160

The Habitat Connection.  

ERIC Educational Resources Information Center

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)

Naturescope, 1987

1987-01-01

161

Aquatic Habitats  

NSDL National Science Digital Library

This lesson plan will help students to understand that the way a community disposes of its wastewater may negatively affect local aquatic habitats, that it is possible to find wastewater-disposal methods that do not pollute, and that both governments and citizens can take action to ensure that waste water will be disposed of in a way that is not destructive. As part of the lesson, students will discuss the definition of "wastewater", how it is disposed of, invite a guest speaker to class, and write proposals to local government officials either suggesting improvements or commending their current procedures. Adaptations for older students, discussion questions, an evaluation rubric, extension activities, suggested readings, a vocabulary, and links to related sites accompany the lesson.

Betsy Hedberg

2003-01-01

162

Quantifying Structural Physical Habitat Attributes Using Lidar and Hyperspectral Imagery (1)  

EPA Science Inventory

Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity, and riparian vegetation cover and structure. The Environmental Monitoring and Assessment Program (EMAP) is designed to assess the status and trends of eco...

163

Quantifying structural physical habitat attributes using LIDAR and hyperspectral imagery - PRK  

EPA Science Inventory

Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity, and riparian vegetation cover and structure. The Environmental Monitoring and Assessment Program (EMAP) is designed to assess the status and trends of ecol...

164

QUANTIFYING STREAM STRUCTURAL PHYSICAL HABITAT ATTRIBUTES USING LIDAR AND HYPERSPECTRAL IMAGERY  

EPA Science Inventory

Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity and cover, riparian vegetation cover and structure, anthropogenic disturbances and channel-riparian interaction. ...

165

Quantifying the Direct Transfer Costs of Common Brushtail Possum Dispersal using Least-Cost Modelling: A Combined Cost-Surface and Accumulated-Cost Dispersal Kernel Approach  

PubMed Central

Dispersal costs need to be quantified from empirical data and incorporated into dispersal models to improve our understanding of the dispersal process. We are interested in quantifying how landscape features affect the immediately incurred direct costs associated with the transfer of an organism from one location to another. We propose that least-cost modelling is one method that can be used to quantify direct transfer costs. By representing the landscape as a cost-surface, which describes the costs associated with traversing different landscape features, least-cost modelling is often applied to measure connectivity between locations in accumulated-cost units that are a combination of both the distance travelled and the costs traversed. However, we take an additional step by defining an accumulated-cost dispersal kernel, which describes the probability of dispersal in accumulated-cost units. This novel combination of cost-surface and accumulated-cost dispersal kernel enables the transfer stage of dispersal to incorporate the effects of landscape features by modifying the direction of dispersal based on the cost-surface and the distance of dispersal based on the accumulated-cost dispersal kernel. We apply this approach to the common brushtail possum (Trichosurus vulpecula) within the North Island of New Zealand, demonstrating how commonly collected empirical dispersal data can be used to calibrate a cost-surface and associated accumulated-cost dispersal kernel. Our results indicate that considerable improvements could be made to the modelling of the transfer stage of possum dispersal by using a cost-surface and associated accumulated-cost dispersal kernel instead of a more traditional straight-line distance based dispersal kernel. We envisage a variety of ways in which the information from this novel combination of a cost-surface and accumulated-cost dispersal kernel could be gainfully incorporated into existing dispersal models. This would enable more realistic modelling of the direct transfer costs associated with the dispersal process, without requiring existing dispersal models to be abandoned. PMID:24505467

Etherington, Thomas R.; Perry, George L. W.; Cowan, Phil E.; Clout, Mick N.

2014-01-01

166

Density-dependent habitat selection in muskrats: a test of the ideal free distribution model  

Microsoft Academic Search

Two predictions of the ideal free distribution model, a null hypothesis of habitat selection, were examined using free-ranging muskrats. We rejected the prediction that the proportion of the animals found in each of five habitats was independent of population size. Data on over-winter occupancy of muskrat dwellings tend also to refute the prediction of equal fitness reward among habitats. Habitat

F. Messier; J. A. Virgl; L. Marinelli

1990-01-01

167

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...

168

Urban Areas. Habitat Pac.  

ERIC Educational Resources Information Center

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…

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

169

Habitat Loss, Not Fragmentation, Drives Occurrence Patterns of Canada Lynx at the Southern Range Periphery  

PubMed Central

Peripheral populations often experience more extreme environmental conditions than those in the centre of a species' range. Such extreme conditions include habitat loss, defined as a reduction in the amount of suitable habitat, as well as habitat fragmentation, which involves the breaking apart of habitat independent of habitat loss. The ‘threshold hypothesis’ predicts that organisms will be more affected by habitat fragmentation when the amount of habitat on the landscape is scarce (i.e., less than 30%) than when habitat is abundant, implying that habitat fragmentation may compound habitat loss through changes in patch size and configuration. Alternatively, the ‘flexibility hypothesis’ predicts that individuals may respond to increased habitat disturbance by altering their selection patterns and thereby reducing sensitivity to habitat loss and fragmentation. While the range of Canada lynx (Lynx canadensis) has contracted during recent decades, the relative importance of habitat loss and habitat fragmentation on this phenomenon is poorly understood. We used a habitat suitability model for lynx to identify suitable land cover in Ontario, and contrasted occupancy patterns across landscapes differing in cover, to test the ‘threshold hypothesis’ and ‘flexibility hypothesis’. When suitable land cover was widely available, lynx avoided areas with less than 30% habitat and were unaffected by habitat fragmentation. However, on landscapes with minimal suitable land cover, lynx occurrence was not related to either habitat loss or habitat fragmentation, indicating support for the ‘flexibility hypothesis’. We conclude that lynx are broadly affected by habitat loss, and not specifically by habitat fragmentation, although occurrence patterns are flexible and dependent on landscape condition. We suggest that lynx may alter their habitat selection patterns depending on local conditions, thereby reducing their sensitivity to anthropogenically-driven habitat alteration. PMID:25401737

Hornseth, Megan L.; Walpole, Aaron A.; Walton, Lyle R.; Bowman, Jeff; Ray, Justina C.; Fortin, Marie-Josée; Murray, Dennis L.

2014-01-01

170

Habitat loss, not fragmentation, drives occurrence patterns of Canada lynx at the southern range periphery.  

PubMed

Peripheral populations often experience more extreme environmental conditions than those in the centre of a species' range. Such extreme conditions include habitat loss, defined as a reduction in the amount of suitable habitat, as well as habitat fragmentation, which involves the breaking apart of habitat independent of habitat loss. The 'threshold hypothesis' predicts that organisms will be more affected by habitat fragmentation when the amount of habitat on the landscape is scarce (i.e., less than 30%) than when habitat is abundant, implying that habitat fragmentation may compound habitat loss through changes in patch size and configuration. Alternatively, the 'flexibility hypothesis' predicts that individuals may respond to increased habitat disturbance by altering their selection patterns and thereby reducing sensitivity to habitat loss and fragmentation. While the range of Canada lynx (Lynx canadensis) has contracted during recent decades, the relative importance of habitat loss and habitat fragmentation on this phenomenon is poorly understood. We used a habitat suitability model for lynx to identify suitable land cover in Ontario, and contrasted occupancy patterns across landscapes differing in cover, to test the 'threshold hypothesis' and 'flexibility hypothesis'. When suitable land cover was widely available, lynx avoided areas with less than 30% habitat and were unaffected by habitat fragmentation. However, on landscapes with minimal suitable land cover, lynx occurrence was not related to either habitat loss or habitat fragmentation, indicating support for the 'flexibility hypothesis'. We conclude that lynx are broadly affected by habitat loss, and not specifically by habitat fragmentation, although occurrence patterns are flexible and dependent on landscape condition. We suggest that lynx may alter their habitat selection patterns depending on local conditions, thereby reducing their sensitivity to anthropogenically-driven habitat alteration. PMID:25401737

Hornseth, Megan L; Walpole, Aaron A; Walton, Lyle R; Bowman, Jeff; Ray, Justina C; Fortin, Marie-Josée; Murray, Dennis L

2014-01-01

171

Living Things: Habitats & Ecosystems  

NSDL National Science Digital Library

Text and photographs regarding habitats, populations and communities, biomes, niches and ecosystems in general with numerous links to lessons, activities, and organizations on specific subtopics in ecology.

2009-01-01

172

India Habitat Centre  

NSDL National Science Digital Library

The India Habitat Centre(IHC) was created in New Delhi, India, to "provide a physical environment [to] serve as a catalyst for a synergetic relationship between individuals and institutions working in diverse habitat related areas." Their website gives visitors a generous glimpse into what it is like to enjoy such features as the "Habitat Film Club", "Habitat Learning Centre", and the "IHC Visual Arts Gallery". Like a multi-faceted community center, the IHC houses a "Habitat Library & Resource Centre" and offers a monthly "Habitat Walk", among other activities. The "Habitat Walk" gives community members the opportunity to visit various natural and historical sites, and provides several pages of background on the sites that visitors can download or print from the "Habitat Walk" link on the website. The center also reaches out and empowers the community by encouraging students and non-students to participate in their annual contest for the Habitat Young Visionary Award, a photography fellowship, and in the recent past, internships in a non-governmental organization.

173

Surface Habitat Systems  

NASA Technical Reports Server (NTRS)

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 the 1) surface habitat concept definition, 2) inflatable surface habitat development, and 3) autonomous habitat operations, and 4) cross-cutting / systems engineering. In subsequent years, the SHS-FIG will solicit a call for innovations and technologies that will support the development of these four development areas. The other development areas will be assessed yearly and identified on the SHS-FIG s Strategic Development Roadmap. Initial investment projects that are funded by the Constellation Program Office (CxPO), LSSPO, or the Exploration Technology Development Projects (ETDP) will also be included on the Roadmap. For example, in one or two years from now, the autonomous habitat operations and testbed would collaborations with the Integrated Systems Health Management (ISHM) and Automation for Operations ETDP projects, which will give the surface habitat projects an integrated habitat autonomy testbed to test software and systems. The SHS-FIG scope is to provide focused direction for multiple innovations, technologies and subsystems that are needed to support humans at a remote planetary surface habitat during the concept development, design definition, and integration phases of that project. Subsystems include: habitability, lightweight structures, power management, communications, autonomy, deployment, outfitting, life support, wireless connectivity, lighting, thermal and more.

Kennedy, Kriss J.

2009-01-01

174

Relative Sensitivities of Mammalian Carnivores to Habitat Fragmentation  

Microsoft Academic Search

I examined the effects of habitat fragmentation on the distribution and abundance of mamma- lian carnivores in coastal southern California and tested the prediction that responses to fragmentation var- ied with the body size of carnivore species. I conducted track surveys for nine native and two exotic carnivore species in 29 urban habitat fragments and 10 control sites. Fragment area

Kevin R. Crooks

2002-01-01

175

Mathematical analysis of the optimal habitat configurations for species persistence  

E-print Network

be the result of climate changes. Indeed warming up can reduce the size of the habitat patches for some mountain.g. Treves et al. [2]). Agricultural and forestry activities are the key drivers of habitat loss affecting, by Fahrig [6], shows that fragmentation per se can also have positive effects on biodiversity, which

Boyer, Edmond

176

RESTORATION OF CARNIVORE HABITAT CONNECTIVITY IN THE NORTHERN ROCKY MOUNTAINS  

Microsoft Academic Search

The Northern Rocky Mountains are the best location in the lower 48 states to maintain functioning communities of large and mid-sized carnivores. Highways and railroads have created significant habitat fragmentation, habitat loss, mortality and other threats to these species. The authors reviewed existing highways and railroads, as well as land ownership patterns. \\

Bill Ruediger; James J. Claar; James F. Gore

177

Schoolyard Habitat Project Guide.  

ERIC Educational Resources Information Center

This project aims to provide basic steps for students to restore and create wildlife habitats on school grounds. Four chapters are included in this guide, and each chapter is divided into teacher and student sections. Chapter 1 provides necessary information for starting a habitat project. Chapters 2, 3, and 4 discuss the details for the Forest…

Mason, Rich

178

Animal Habitat MEA  

NSDL National Science Digital Library

Animal Habitat MEA is where the students will help a pet store choose which habitat they should buy to house their snake and lizard families. The students will solve an open-ended problem and give details on the process that they used to solve the problem.

jennifer zagarella

2012-07-31

179

Home Sweet Habitat  

NSDL National Science Digital Library

This lesson demonstrates how students can compare and contrast different types of habitats. The lesson provides the opportunity for students to apply reading concepts while encountering nonfiction text. This lesson provides students with the opportunity to read and discuss various nonfiction selections about habitats and includes a jigsaw learning activity.

2013-03-01

180

Rocky Intertidal Habitats  

NSDL National Science Digital Library

This resource describes the rocky intertidal habitats of the Monterey Bay National Marine Sanctuary and their biological diversity, distribution patterns, temporal changes, links to other habitats and assemblages, and management issues. Supporting materials include photos, tables, figures, and in-text definitions.

181

The Habitat Project  

ERIC Educational Resources Information Center

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…

Hein, Annamae J.

2011-01-01

182

Anopheline Larval Habitats Seasonality and Species Distribution: A Prerequisite for Effective Targeted Larval Habitats Control Programmes  

PubMed Central

Background 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. Methods and Findings 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. Conclusion These findings suggest that implementation of effective larval control programme should be targeted with larval habitats succession information when larval habitats are fewer and manageable. Crop cycles and distance from habitats to household should be considered as effective information in planning larval control. PMID:23272215

Kweka, Eliningaya J.; Zhou, Guofa; Munga, Stephen; Lee, Ming-Chieh; Atieli, Harrysone E.; Nyindo, Mramba; Githeko, Andrew K.; Yan, Guiyun

2012-01-01

183

Lunar Habitat Optimization Using Genetic Algorithms  

NASA Technical Reports Server (NTRS)

Long-duration surface missions to the Moon and Mars will require bases to accommodate habitats for the astronauts. Transporting the materials and equipment required to build the necessary habitats is costly and difficult. The materials chosen for the habitat walls play a direct role in protection against each of the mentioned hazards. Choosing the best materials, their configuration, and the amount required is extremely difficult due to the immense size of the design region. Clearly, an optimization method is warranted for habitat wall design. Standard optimization techniques are not suitable for problems with such large search spaces; therefore, a habitat wall design tool utilizing genetic algorithms (GAs) has been developed. GAs 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 multiobjective formulation of up-mass, heat loss, structural analysis, meteoroid impact protection, and radiation protection. This Technical Publication presents the research and development of this tool as well as a technique for finding the optimal GA search parameters.

SanScoucie, M. P.; Hull, P. V.; Tinker, M. L.; Dozier, G. V.

2007-01-01

184

Probable consequences of high female mortality for speckled warblers living in habitat remnants  

Microsoft Academic Search

The effects of habitat fragmentation on the Australian avifauna have been widespread with species richness and abundance declining with reduced remnant size and habitat quality and increased habitat isolation. The speckled warbler, Chthonicola sagittata is one species from the highly fragmented temperate woodlands of eastern Australia that has declined across its range and populations that remain appear to be patchily

J. L. Gardner; R. G. Heinsohn

2007-01-01

185

Specialization in habitat use by coral reef damselfishes and their susceptibility to habitat loss.  

PubMed

While it is generally assumed that specialist species are more vulnerable to disturbance compared with generalist counterparts, this has rarely been tested in coastal marine ecosystems, which are increasingly subject to a wide range of natural and anthropogenic disturbances. Habitat specialists are expected to be more vulnerable to habitat loss because habitat availability exerts a greater limitation on population size, but it is also possible that specialist species may escape effects of disturbance if they use habitats that are generally resilient to disturbance. This study quantified specificity in use of different coral species by six coral-dwelling damselfishes (Chromis viridis, C. atripectoralis, Dascyllus aruanus, D. reticulatus, Pomacentrus moluccensis, and P. amboinensis) and related habitat specialization to proportional declines in their abundance following habitat degradation caused by outbreaks of the coral eating starfish, Acanthaster planci. The coral species preferred by most coral-dwelling damselfishes (e.g., Pocillopora damicornis) were frequently consumed by coral eating crown-of-thorns starfish, such that highly specialized damselfishes were disproportionately affected by coral depletion, despite using a narrower range of different coral species. Vulnerability of damselfishes to this disturbance was strongly correlated with both their reliance on corals and their degree of habitat specialization. Ongoing disturbances to coral reef ecosystems are expected, therefore, to lead to fundamental shifts in the community structure of fish communities where generalists are favored over highly specialist species. PMID:23139876

Pratchett, Morgan S; Coker, Darren J; Jones, Geoffrey P; Munday, Philip L

2012-09-01

186

Specialization in habitat use by coral reef damselfishes and their susceptibility to habitat loss  

PubMed Central

While it is generally assumed that specialist species are more vulnerable to disturbance compared with generalist counterparts, this has rarely been tested in coastal marine ecosystems, which are increasingly subject to a wide range of natural and anthropogenic disturbances. Habitat specialists are expected to be more vulnerable to habitat loss because habitat availability exerts a greater limitation on population size, but it is also possible that specialist species may escape effects of disturbance if they use habitats that are generally resilient to disturbance. This study quantified specificity in use of different coral species by six coral-dwelling damselfishes (Chromis viridis, C. atripectoralis, Dascyllus aruanus, D. reticulatus, Pomacentrus moluccensis, and P. amboinensis) and related habitat specialization to proportional declines in their abundance following habitat degradation caused by outbreaks of the coral eating starfish, Acanthaster planci. The coral species preferred by most coral-dwelling damselfishes (e.g., Pocillopora damicornis) were frequently consumed by coral eating crown-of-thorns starfish, such that highly specialized damselfishes were disproportionately affected by coral depletion, despite using a narrower range of different coral species. Vulnerability of damselfishes to this disturbance was strongly correlated with both their reliance on corals and their degree of habitat specialization. Ongoing disturbances to coral reef ecosystems are expected, therefore, to lead to fundamental shifts in the community structure of fish communities where generalists are favored over highly specialist species. PMID:23139876

Pratchett, Morgan S; Coker, Darren J; Jones, Geoffrey P; Munday, Philip L

2012-01-01

187

Carnivore body size: Ecological and taxonomic correlates  

Microsoft Academic Search

Variation in body size (weight) is examined across the order Carnivora in relation to taxonomy (phylogeny), latitude, habitat, zonation, activity cycle, diet, prey size, and prey diversity. Significant differences in body weight are observed with respect to family membership. Some of these differences may be explained by phylogenetic history and\\/or dietary effects. Body weight is not correlated with habitat, zonation,

John L. Gittleman

1985-01-01

188

Observing Wetland Habitats  

NSDL National Science Digital Library

Observing Wetland Habitats contains tips on finding wetlands to explore and wetland scavenger hunt observation sheets that can be used as a starting point for discovery. While on their scavenger hunt, students can look for adaptations in plants and animals that help them live in a partially wet habitat. After the students have finished their scavenger hunt, they can share what they've seen and heard.

189

Habitat Suitability Index Models: Fallfish  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for fallfish (Semotilis corporalis), a freshwater species. The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for freshwater, marine and estuarine areas of the continental 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 Fallfish habitat.

Trial, Joan G.; Wade, Charles S.; Stanley, Jon G.; Nelson, Patrick C.

1983-01-01

190

Living Things and their Habitats  

NSDL National Science Digital Library

Students will learn how to tell the difference between living and non-living organisms and their habitats. Our class has just learned about living things and their habitats. Use this webquest to create your own living things and their habitats. Remember a living thing: Grows Moves Reproduces A Habitat is a place (home) for living things. A habitat provides four important things: 1. Food 2. Shelter 3. Space 4. Water Now you get to decide ...

Mrs. D.

2006-10-11

191

Habitat Suitability Index Models: Pronghorn  

USGS Publications Warehouse

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.

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

1984-01-01

192

Habitat Suitability Index Models: Bullfrog  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the bullfrog (Rana catesbeiana). 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.

Graves, Brent M.; Anderson, Stanley H.

1987-01-01

193

Habitat Suitability Index Models: Muskellunge  

USGS Publications Warehouse

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.

Cook, Mark F.; Solomon, R. Charles

1987-01-01

194

Habitat Suitability Index Models: Bobcat  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the bobcat (Felis rufus). 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.

Boyle, Katherine A.; Fendley, Timothy T.

1987-01-01

195

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

USGS Publications Warehouse

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.

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

2009-01-01

196

Determinants of habitat selection by hatchling Australian freshwater crocodiles.  

PubMed

Animals almost always use habitats non-randomly, but the costs and benefits of using specific habitat types remain unknown for many types of organisms. In a large lake in northwestern Australia (Lake Argyle), most hatchling (<12-month-old) freshwater crocodiles (Crocodylus johnstoni) are found in floating vegetation mats or grassy banks rather than the more widely available open banks. Mean body sizes of young crocodiles did not differ among the three habitat types. We tested four potential explanations for non-random habitat selection: proximity to nesting sites, thermal conditions, food availability, and exposure to predation. The three alternative habitat types did not differ in proximity to nesting sites, or in thermal conditions. Habitats with higher food availability harboured more hatchlings, and feeding rates (obtained by stomach-flushing of recently-captured crocodiles) were highest in such areas. Predation risk may also differ among habitats: we were twice as likely to capture a crocodile after seeing it in open-bank sites than in the other two habitat types. Thus, habitat selection of hatchling crocodiles in this system may be driven both by prey availability and by predation risk. PMID:22163308

Somaweera, Ruchira; Webb, Jonathan K; Shine, Richard

2011-01-01

197

Habitat type and ambient temperature contribute to bill morphology.  

PubMed

Avian bills are iconic structures for the study of ecology and evolution, with hypotheses about the morphological structure of bills dating back to Darwin. Several ecological and physiological hypotheses have been developed to explain the evolution of the morphology of bill shape. Here, we test some of these hypotheses such as the role of habitat, ambient temperature, body size, intraspecific competition, and ecological release on the evolution of bill morphology. Bill morphology and tarsus length were measured from museum specimens of yellow warblers, and grouped by habitat type, sex, and subspecies. We calculated the mean maximum daily temperature for the month of July, the hottest month for breeding specimens at each collecting location. Analysis of covariance models predicted total bill surface area as a function of sex, habitat type, body size, and temperature, and model selection techniques were used to select the best model. Habitat, mangrove forests compared with inland habitats, and climate had the largest effects on bill size. Coastal wetland habitats and island populations of yellow warblers had similar bill morphology, both of which are larger than mainland inland populations. Temperate but not tropical subspecies exhibited sexual dimorphism in bill morphology. Overall, this study provides evidence that multiple environmental factors, such as temperature and habitat, contribute to the evolution of bill morphology. PMID:24683453

Luther, David; Greenberg, Russell

2014-03-01

198

Habitat type and ambient temperature contribute to bill morphology  

PubMed Central

Avian bills are iconic structures for the study of ecology and evolution, with hypotheses about the morphological structure of bills dating back to Darwin. Several ecological and physiological hypotheses have been developed to explain the evolution of the morphology of bill shape. Here, we test some of these hypotheses such as the role of habitat, ambient temperature, body size, intraspecific competition, and ecological release on the evolution of bill morphology. Bill morphology and tarsus length were measured from museum specimens of yellow warblers, and grouped by habitat type, sex, and subspecies. We calculated the mean maximum daily temperature for the month of July, the hottest month for breeding specimens at each collecting location. Analysis of covariance models predicted total bill surface area as a function of sex, habitat type, body size, and temperature, and model selection techniques were used to select the best model. Habitat, mangrove forests compared with inland habitats, and climate had the largest effects on bill size. Coastal wetland habitats and island populations of yellow warblers had similar bill morphology, both of which are larger than mainland inland populations. Temperate but not tropical subspecies exhibited sexual dimorphism in bill morphology. Overall, this study provides evidence that multiple environmental factors, such as temperature and habitat, contribute to the evolution of bill morphology. PMID:24683453

Luther, David; Greenberg, Russell

2014-01-01

199

Habitat for Humanity  

NSDL National Science Digital Library

Founded in 1976, Habitat for Humanity has constructed over 175,000 houses, which provides homes for over 1 million people. While the organization's most famous volunteer may be former President Jimmy Carter, the group is always on the lookout for other interested parties who would like to give generously of their time. The organization's website contains information on the history of Habitat, along with information about donating and volunteering for the organization. To get a sense of the scope of their work, visitors will want to take a look at the "Where We Build" section of the site. Utilizing a clickable map, visitors can learn about their different home-building efforts in the countries they serve. To really delve into the work of the organization, visitors would do well to peruse the latest edition of Habitat's "Faces and Places" magazine, which contains articles on rural poverty housing initiatives.

2005-01-01

200

Wildlife Habitat Council  

NSDL National Science Digital Library

Cooperation among industry and conservation groups can be rare indeed, and when the Wildlife Habitat Council was formed in 1988, it was certainly an unusual arrangement. Over the past several decades, the Council has worked to ease some of these tensions “to search for innovative joint ventures in environmental stewardship.” Visitors interested in such matters will appreciate the organization’s website, which brings together materials on brownfield remediation, nest monitoring, and wildlife management tools. Additionally, visitors can also learn about some of their recent industry partnerships, including the Cuyahoga Habitat partnership and the St. Clair River Waterways for Wildlife Project. The site is rounded out by a “Publications” area which contains a number of web-only articles by staff members and a list of books on sustainability and wildlife habitat management handpicked by WHC staff members.

201

Habitat goes green  

SciTech Connect

A Denver family enjoys the financial and personal benefits of owning an affordable, energy-efficient home. On Earth Day, April 22, 1997, Habitat for Humanity of Metro Denver witnessed the realization of a dream. As Luis and Estella Valadez and their four children cut the ribbon on their 1,100 square foot (102 m{sup 2}) northwest Denver home, it signified the completion of the Denver Habitat affiliate's first ``Green'' home. Building this dream involved developing a plan to build affordable Habitat homes that also embodied a sense of stewardship of the Earth's environment. The affiliate also wanted to use this effort to achieve the additional goal of reducing the homeowner's utility and maintenance bills.

Kriescher, P.; Smith, M.

1999-12-01

202

Habitat Suitability Information: Blacknose Dace  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for Blacknose dace, a freshwater species. The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for freshwater, marine, and estuarine areas of the continental 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 Blacknose dace.

Trial, Joan G.; Stanley, Jon G.; Batcheller, Mary; Gebhart, Gary; Maughan, O. Eugene; Nelson, Patrick C.

1983-01-01

203

Habitat Suitability Index Models: Beaver  

USGS Publications Warehouse

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.

Allen, Arthur W.

1982-01-01

204

Habitat filtering across tree life stages in tropical forest communities  

PubMed Central

Tropical tree communities are shaped by local-scale habitat heterogeneity in the form of topographic and edaphic variation, but the life-history stage at which habitat associations develop remains poorly understood. This is due, in part, to the fact that previous studies have not accounted for the widely disparate sample sizes (number of stems) that result when trees are divided into size classes. We demonstrate that the observed habitat structuring of a community is directly related to the number of individuals in the community. We then compare the relative importance of habitat heterogeneity to tree community structure for saplings, juveniles and adult trees within seven large (24–50 ha) tropical forest dynamics plots while controlling for sample size. Changes in habitat structuring through tree life stages were small and inconsistent among life stages and study sites. Where found, these differences were an order of magnitude smaller than the findings of previous studies that did not control for sample size. Moreover, community structure and composition were very similar among tree sub-communities of different life stages. We conclude that the structure of these tropical tree communities is established by the time trees are large enough to be included in the census (1 cm diameter at breast height), which indicates that habitat filtering occurs during earlier life stages. PMID:23843384

Baldeck, C. A.; Harms, K. E.; Yavitt, J. B.; John, R.; Turner, B. L.; Valencia, R.; Navarrete, H.; Bunyavejchewin, S.; Kiratiprayoon, S.; Yaacob, A.; Supardi, M. N. N.; Davies, S. J.; Hubbell, S. P.; Chuyong, G. B.; Kenfack, D.; Thomas, D. W.; Dalling, J. W.

2013-01-01

205

Managing harvest and habitat as integrated components  

USGS Publications Warehouse

In 2007, several important initiatives in the North American waterfowl management community called for an integrated approach to habitat and harvest management. The essence of the call for integration is that harvest and habitat management affect the same resources, yet exist as separate endeavours with very different regulatory contexts. A common modelling framework could help these management streams to better understand their mutual effects. Particularly, how does successful habitat management increase harvest potential? Also, how do regional habitat programmes and large-scale harvest strategies affect continental population sizes (a metric used to express habitat goals)? In the ensuing five years, several projects took on different aspects of these challenges. While all of these projects are still on-going, and are not yet sufficiently developed to produce guidance for management decisions, they have been influential in expanding the dialogue and producing some important emerging lessons. The first lesson has been that one of the more difficult aspects of integration is not the integration across decision contexts, but the integration across spatial and temporal scales. Habitat management occurs at local and regional scales. Harvest management decisions are made at a continental scale. How do these actions, taken at different scales, combine to influence waterfowl population dynamics at all scales? The second lesson has been that consideration of the interface of habitat and harvest management can generate important insights into the objectives underlying the decision context. Often the objectives are very complex and trade-off against one another. The third lesson follows from the second – if an understanding of the fundamental objectives is paramount, there is no escaping the need for a better understanding of human dimensions, specifically the desires of hunters and nonhunters and the role they play in conservation. In the end, the compelling question is how to better understand, guide and justify decisions about conservation investments in waterfowl management. Future efforts to integrate harvest and habitat management will include completion of the species-specific case-studies, initiation of policy discussions around how to integrate the decision contexts and governing institutions, and possible consideration of a new level of integration – integration of harvest and habitats management decisions across waterfowl stocks.

Osnas, Erik; Runge, Michael C.; Mattsson, Brady J.; Austin, Jane E.; Boomer, G. S.; Clark, R. G.; Devers, P.; Eadie, J. M.; Lonsdorf, E. V.; Tavernia, Brian

2014-01-01

206

Food Availability and Tiger Shark Predation Risk Influence Bottlenose Dolphin Habitat Use  

Microsoft Academic Search

Although both food availability and predation risk have been hypothesized to affect dolphin habitat use and group size, no study has measured both factors concurrently to determine their relative influences. From 1997 to 1999, we investigated the effect of food availability and tiger shark (Galeocerdo cuvier) predation risk on bottlenose dolphin (Tursiops aduncus) habitat use and group size in Shark

Michael R. Heithaus; Lawrence M. Dill

2002-01-01

207

Floods, Habitat Hydraulics and Upstream Migration of Neritina virginea (Gastropoda: Neritidae) in Northeastern Puerto Rico  

E-print Network

Floods, Habitat Hydraulics and Upstream Migration of Neritina virginea (Gastropoda: Neritidae a detailed study of snail density, size, and hydraulic descriptors in lower Río Mameyes, northeastern Puerto and size dynamics differed between reaches as a function of habitat hydraulics. While juveniles used

208

Earth is a Marine Habitat. Habitat Conservation Program.  

ERIC Educational Resources Information Center

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 Life,""Oceans and the United…

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

209

Reclaiming surface minded land to waterfowl habitat  

SciTech Connect

One of the most striking and persistent characteristics of surface-mined land is the hole left in the ground after mining. Mines can cause large disturbances that cover many square miles, or small ones that affect less than one acre. Any size mine can be reclaimed to waterfowl habitat if certain issues can be resolved. This article proposes solutions for some of these issues and describes several reclaimed mine sites in California.

Lacy, M.K.

1996-03-01

210

Habitat Suitability Index Models: Bluegill  

USGS Publications Warehouse

A literature review encompassing habitat and species characteristics of the bluegill (Lepomis macrochirus) is followed by a discussion of the relationship of habitat variables and life requisites of this species. These data re then incorporated into Habitat Suitability Index models for the bluegill. This is one in a series of publications describing 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 Habitat Suitability Index (HSI) models. the models are based on suitability indices formulated for variables found to affect the life cycle and survival of the species. The models are designed to be modified to evaluate specific habitat alterations using the HSI model building techniques presented in the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures.

Stuber, Robert J.; Gebhart, Glen; Maughan, O. Eugene

1982-01-01

211

Modeling sensitive elasmobranch habitats  

NASA Astrophysics Data System (ADS)

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-? 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.

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

2013-10-01

212

Habitats of the Pond  

NSDL National Science Digital Library

In this outdoor activity/field trip, learners locate and study plants and animals in several freshwater pond habitats. Learners take various samples from the pond, identify organisms using a pond guide, and collaborate to create a pond map. Includes background information, but it is recommended that learners do the activity What Lives Here?, also by OBIS, before this activity.

Lawrence Hall of Science

1981-01-01

213

MAINE MARINE WORM HABITAT  

EPA Science Inventory

WORM provides a generalized representation at 1:24,000 scale of commercially harvested marine worm habitat in Maine, based on Maine Department of Marine Resources data from 1970's. Original maps were created by MDMR and published by USF&WS as part of the ""&quo...

214

THE BIOLOGY OF RARE AND DECLINING SPECIES AND HABITATS  

E-print Network

-history attniutes that limit their population size. Limited distributions may occurwhen a species is endemic to extinctions. Their primary influence may be to limit populations in size and distniution to the point when in population and habitat declines. Human activity exertsexternal energy to the environment that accelerates

215

Linking habitat mosaics and connectivity in a coral reef seascape.  

PubMed

Tropical marine ecosystems are under mounting anthropogenic pressure from overfishing and habitat destruction, leading to declines in their structure and function on a global scale. Although maintaining connectivity among habitats within a seascape is necessary for preserving population resistance and resilience, quantifying movements of individuals within seascapes remains challenging. Traditional methods of identifying and valuing potential coral reef fish nursery habitats are indirect, often relying on visual surveys of abundance and correlations of size and biomass among habitats. We used compound-specific stable isotope analyses to determine movement patterns of commercially important fish populations within a coral reef seascape. This approach allowed us to quantify the relative contributions of individuals from inshore nurseries to reef populations and identify migration corridors among important habitats. Our results provided direct measurements of remarkable migrations by juvenile snapper of over 30 km, between nurseries and reefs. We also found significant plasticity in juvenile nursery residency. Although a majority of individuals on coastal reefs had used seagrass nurseries as juveniles, many adults on oceanic reefs had settled directly into reef habitats. Moreover, seascape configuration played a critical but heretofore unrecognized role in determining connectivity among habitats. Finally, our approach provides key quantitative data necessary to estimate the value of distinctive habitats to ecosystem services provided by seascapes. PMID:22949665

McMahon, Kelton W; Berumen, Michael L; Thorrold, Simon R

2012-09-18

216

Concepts for a Shroud or Propellant Tank Derived Deep Space Habitat  

NASA Technical Reports Server (NTRS)

Long duration human spaceflight missions beyond Low Earth Orbit will require much larger spacecraft than capsules such as the Russian Soyuz or American Orion Multi-Purpose Crew Vehicle. A concept spacecraft under development is the Deep Space Habitat, with volumes approaching that of space stations such as Skylab, Mir, and the International Space Station. This paper explores several concepts for Deep Space Habitats constructed from a launch vehicle shroud or propellant tank. It also recommends future research using mockups and prototypes to validate the size and crew station capabilities of such a habitat. Keywords: Exploration, space station, lunar outpost, NEA, habitat, long duration, deep space habitat, shroud, propellant tank.

Howard, Robert L.

2012-01-01

217

Comparison of responses to alarm calls by patas (Erythrocebus patas) and vervet (Cercopithecus aethiops) monkeys in relation to habitat structure.  

PubMed

We studied responses to alarm calls of sympatric patas (Erythrocebus patas) and vervet (Cercopithecus aethiops) monkeys in relation to habitat structure, with the intention of understanding the relationship between the environment and predator avoidance. Patas and vervet monkeys are phylogenetically closely related and overlap in body size. However, while patas monkeys are restricted to nonriverine habitats at our study site, vervets use both nonriverine and riverine habitats, allowing us to "vary" habitat structure while controlling for effects of group size, composition, and phylogeny. Patas monkeys in the nonriverine habitat responded to mammalian predator alarm calls with a greater variety of responses than did vervets in the riverine habitat, but not when compared with vervets in the nonriverine habitat. Ecological measurements confirm subjective assessments that trees in the riverine habitat are significantly taller and occur at lower densities than trees in the nonriverine habitat. Despite the lower density of trees in the riverine habitat, locomotor behavior of focal animals indicates that canopy cover is significantly greater in the riverine than the nonriverine habitat. Differences in responses to alarm calls by the same groups of vervets in different habitat types, and convergence of vervets with patas in the same habitat type, suggest that habitat type can be a significant source of variation in antipredator behavior of primates. PMID:12209569

Enstam, Karin L; Isbell, Lynne A

2002-09-01

218

Geomorphology and stream habitat relationships with smallmouth bass ( Micropterus dolomieu ) abundance at multiple spatial scales in eastern Oklahoma  

Microsoft Academic Search

Fluvial geomorphic processes structure habitats important to stream fishes. We determined relationships between densities of smallmouth bass (Micropterus dolomieu) and ecoregions, watershed and reach morphology, and stream habitat in eastern Oklahoma, USA. Watershed and reach morphology were measured at 128 stream sites, and stream habitat and smallmouth bass abundance were measured in 1800 channel units. Variation in stream size, channel

Daniel C. Dauwalter; Dale K. Splinter; William L. Fisher; Richard A. Marston

2007-01-01

219

An Interpolation Method for Stream Habitat Assessments  

Microsoft Academic Search

Interpolation of stream habitat can be very useful for habitat assessment. Using a small number of habitat samples to predict the habitat of larger areas can reduce time and labor costs as long as it provides accurate estimates of habitat. The spatial correlation of stream habitat variables such as substrate and depth improves the accuracy of interpolated data. Several geographical

Kenneth R. Sheehan; Stuart A. Welsh

2009-01-01

220

Morphological polymorphism of Trypanosoma copemani and description of the genetically diverse T. vegrandis sp. nov. from the critically endangered Australian potoroid, the brush-tailed bettong (Bettongia penicillata (Gray, 1837))  

PubMed Central

Background The trypanosome diversity of the Brush-tailed Bettong (Bettongia penicillata), known locally as the woylie, has been further investigated. At a species level, woylies are critically endangered and have declined by 90% since 1999. The predation of individuals made more vulnerable by disease is thought to be the primary cause of this decline, but remains to be proven. Methods Woylies were sampled from three locations in southern Western Australia. Blood samples were collected and analysed using fluorescence in situ hybridization, conventional staining techniques and microscopy. Molecular techniques were also used to confirm morphological observations. Results The trypanosomes in the blood of woylies were grouped into three morphologically distinct trypomastigote forms, encompassing two separate species. The larger of the two species, Trypanosoma copemani exhibited polymorphic trypomastigote forms, with morphological phenotypes being distinguishable, primarily by the distance between the kinetoplast and nucleus. The second trypanosome species was only 20% of the length of T. copemani and is believed to be one of the smallest recorded trypanosome species from mammals. No morphological polymorphism was identified for this genetically diverse second species. We described the trypomastigote morphology of this new, smaller species from the peripheral blood of the woylie and proposed the name T. vegrandis sp. nov. Temporal results indicate that during T. copemani Phenotype 1 infections, the blood forms remain numerous and are continuously detectable by molecular methodology. In contrast, the trypomastigote forms of T. copemani Phenotype 2 appear to decrease in prevalence in the blood to below molecular detectable levels. Conclusions Here we report for the first time on the morphological diversity of trypanosomes infecting the woylie and provide the first visual evidence of a mixed infection of both T. vegrandis sp. nov and T. copemani. We also provide supporting evidence that over time, the intracellular T. copemani Phenotype 2 may become localised in the tissues of woylies as the infection progresses from the active acute to chronic phase. As evidence grows, further research will be necessary to investigate whether the morphologically diverse trypanosomes of woylies have impacted on the health of their hosts during recent population declines. PMID:23622560

2013-01-01

221

Design a Panda Habitat  

NSDL National Science Digital Library

In this online activity, learners design a new giant panda habitat for Mei Xiang and Tian Tian. Learners must balance the needs of the pandas, visitors, and staff in order to create a hospitable and enjoyable environment for the pandas to live in. Learners use hints and tips from zoo staff to select the features of the new exhibit including trees/plants, water features, enrichment, climate control, food, and research/observation elements.

Smithsonian National Zoological Park

2012-06-26

222

Defining dynamic pelagic habitats in oceanic waters off eastern Australia  

NASA Astrophysics Data System (ADS)

Although many species in the pelagic ocean are widespread, they are not randomly distributed. These species may have associations with particular water masses or habitats, but to best understand patterns in the ocean, these habitats must be identified. Previous efforts have produced static or seasonal climatologies, which still represent smearing over habitats. The Eastern Tuna and Billfish Longline Fishery (ETBF) targets a range of high trophic level species in oceanic waters off eastern Australia. In this study, dynamic ocean habitats in the region were identified for each month based on cluster analysis of five oceanographic variables averaged at a monthly time scale and a spatial scale of 0.5° for the period 1995-2006. A total of seven persistent habitats were identified off eastern Australia with intra and interannual variation in size and location, indicating the importance of spatial and temporal variation in the dynamics of the region. The degree to which these dynamic habitats were distinguished was tested using (i) stable isotope analysis of top fish predators caught in the region and (ii) estimates of variation in estimated abundance generated from catch data from the fishery. More precise estimates (measured as lower total CV) of isotopic values from swordfish ( Xiphias gladius), yellowfin tuna ( Thunnus albacares) and albacore ( Thunnus alalunga) were obtained for 4 of 6 isotope comparisons using the dynamic habitat groupings, which indicate that stratifying by pelagic habitat improved precision. Dynamic habitats produced more precise abundance estimates for 7 of 8 large pelagic species examined, with an average reduction in total CV of 19% compared to when abundance was estimated based on static habitat stratification. These findings could be used to guide development of effective monitoring strategies that can distinguish patterns due to environmental variation, and in the longer term, climate change.

Hobday, A. J.; Young, J. W.; Moeseneder, C.; Dambacher, J. M.

2011-03-01

223

Body mass explains characteristic scales of habitat selection in terrestrial mammals  

PubMed Central

Niche theory in its various forms is based on those environmental factors that permit species persistence, but less work has focused on defining the extent, or size, of a species’ environment: the area that explains a species’ presence at a point in space. We proposed that this habitat extent is identifiable from a characteristic scale of habitat selection, the spatial scale at which habitat best explains species’ occurrence. We hypothesized that this scale is predicted by body size. We tested this hypothesis on 12 sympatric terrestrial mammal species in the Canadian Rocky Mountains. For each species, habitat models varied across the 20 spatial scales tested. For six species, we found a characteristic scale; this scale was explained by species’ body mass in a quadratic relationship. Habitat measured at large scales best-predicted habitat selection in both large and small species, and small scales predict habitat extent in medium-sized species. The relationship between body size and habitat selection scale implies evolutionary adaptation to landscape heterogeneity as the driver of scale-dependent habitat selection. PMID:22393519

Fisher, Jason T; Anholt, Brad; Volpe, John P

2011-01-01

224

Habitat Suitability Index Models: Brewer's Sparrow  

USGS Publications Warehouse

This document is part of the Habitat Suitability Index (HSI) model series, which provides habitat information useful for impact assessment and habitat management for the Brewer's sparrow (Spizella breweri). Several types of habitat information are provided. A Habitat Use Information Section can be used to drive quantitative relationships between key environmental variables and habitat suitability. The HSI Model Section documents a habitat model and information pertinent to its application. The model synthesizes the habitat use information into a framework appropriate for field application and is scaled to produce an index value between 0.0 (unsuitable habitat) to 1.0 (optimum habitat).

Short, Henry L.

1984-01-01

225

The Habitat Quality of Private Land Box-Ironbark Remnant Vegetation in Southern Australia  

Microsoft Academic Search

Approximately 75% of the Victorian Box-Ironbark ecosystem has been cleared since European settlement. There are few public land areas of high habitat quality, and significant Box-Ironbark remnant vegetation (BIR) is known to exist on private land. A landholder mail survey collected information about BIR to ascertain its size, use and habitat quality. Ground-truthing validated the landholder assessment of habitat quality.

S. D. Hamilton; C. ODwyer; P. D. Dettmann; A. L. Curtis

2005-01-01

226

Absent or undetected? Effects of non-detection of species occurrence on wildlife–habitat models  

Microsoft Academic Search

Presence–absence data are used widely in analysis of wildlife–habitat relationships. Failure to detect a species’ presence in an occupied habitat patch is a common sampling problem when the population size is small, individuals are difficult to sample, or sampling effort is limited. In this paper, the influence of non-detection of occurrence on parameter estimates of logistic regression models of wildlife–habitat

Weidong Gu; Robert K. Swihart

2004-01-01

227

Scale-specific correlations between habitat heterogeneity and soil fauna diversity along a landscape structure gradient  

Microsoft Academic Search

Habitat heterogeneity contributes to the maintenance of diversity, but the extent that landscape-scale rather than local-scale\\u000a heterogeneity influences the diversity of soil invertebrates—species with small range sizes—is less clear. Using a Scottish\\u000a habitat heterogeneity gradient we correlated Collembola and lumbricid worm species richness and abundance with different elements\\u000a (forest cover, habitat richness and patchiness) and qualities (plant species richness, soil

Adam J. Vanbergen; Allan D. Watt; Ruth Mitchell; Anne-Marie Truscott; Stephen C. F. Palmer; Eva Ivits; Paul Eggleton; T. Hefin Jones; José Paulo Sousa

2007-01-01

228

Habitat use by Red-tailed Hawks in surface-mined areas  

Microsoft Academic Search

Habitat use by 4 radio-tagged red-tailed hawks (Buteo jamaicensis) was monitored during 708 transmitter-days in coal surface-mined areas in northern West Virginia and southwestern Pennsylvania in 1977 and 1978. Mean cumulative home range size for the 3 adults was 316.8 ha (3.2 km2). Red-tailed hawks showed significant (P<0.005) tendencies to elect certain habitats over others. Descending order of habitat electivity

David P. Mindell; David E. Samuel

1984-01-01

229

Habitat Conservation Planning Support  

NSDL National Science Digital Library

This site provides an overview of the concept of habitat conservation planning (HCP), a program administered by the U.S. Fish and Wildlife Service. The information includes descriptions of the primary aspects of HCP: collection of ecological field data; design of reserves; analysis of the impacts that may result in the extinction of vulnerable species; monitoring to evaluate the progress of a given HCP; and areas of support such as geographic information systems (GIS), remote sensing, and simulation modeling. There are also links to examples of current research being conducted to support each of these aspects.

230

Critical Habitats, Inc  

NSDL National Science Digital Library

The site listed here is provided by an environmental consulting firm that works with commercial and private landowners to establish Wetland Banks. An innovative concept (and growing reality) that has received mixed reviews from scientists, Wetland Banking attempts to combine the goals of developers (i.e., to develop a certain area) and wetland conservationists (i.e., to maintain/ restore areas of intact wetlands). If misused, this approach could work against wetland conservation; if properly instated, however, Wetland Banking might offer an alternative to the currently poor success rate of wetland mitigation projects. This site, from Critical Habitats, Inc., provides additional straightforward information on Wetland Banking.

231

Introducing Habitats and Biodiversity  

NSDL National Science Digital Library

In this activity, students identify habitats in Arizona, define and illustrate a food web in a kinesthetic exercise, and explain the importance of biodiversity in a writing assignment. Required materials include a ball of yarn or string. The resource includes two student worksheets, a data sheet, answer keys, and Web links. This is Lesson 1 in the unit on Biodiversity, part of IMAGERS, Interactive Media Adventures for Grade School Education using Remote Sensing. The website provides hands-on activities in the classroom supporting the science content in two interactive media books, The Adventures of Echo the Bat and Amelia the Pigeon.

232

Brook Trout (Salvelinus fontinalis) Habitat Preferences and In-stream Habitat Diversity Indices  

NASA Astrophysics Data System (ADS)

Many stream restoration projects aim to restore some level of complexity to streams that have been simplified through human impacts (due to straightening or removal of flow obstructions). The importance of hydraulic and structural complexity on brook trout (Salvelinus fontinalis) habitat preferences was assessed in the high- gradient Staunton River in the Shenandoah National Park, Virginia, USA. The in-stream habitat of the Staunton River was altered in 1995 by a 500-year flood and debris flow. Following this event, fish surveys have been conducted annually for 1.0 km within and above the impacted sections of the stream using a fine- resolution sampling protocol (fish sampling every 10-30 m). Detailed topographic surveys were conducted on two 80-m sub-reaches, one within the area affected by the debris flow, and one upstream in the unimpacted section. Other habitat variables measured at the local scale included large woody debris, under-cut boulders, overhanging vegetation, substrate size, and riparian cover. Structural complexity was calculated from topographic surveys as the deviation from a flat bottom. A two-dimensional hydraulic model (River2D) was used to calculate the area-weighted circulation used as a measure of hydraulic complexity. The in-stream cover (wake area behind boulders) was also calculated using the model results. The importance of these habitat variables to brook trout habitat preferences at the local scale was evaluated using principal components analysis in both the debris flow affected and the unimpacted reaches. Understanding the relationships between structural complexity and hydraulic complexity will result in quantifiable metrics for evaluating stream restoration project impacts on in-stream habitat quality.

Kozarek, J. L.; Hession, W. C.

2008-12-01

233

Sexual size dimorphism and sexual selection in turtles (order testudines)  

Microsoft Academic Search

This paper combines published and original data on sexual size dimorphism, reproductive behavior, and habitat types in turtles. Our major finding is that observed patterns of sexual size dimorphism correlate with habitat type and male mating strategy. (1) In most terrestrial species, males engage in combat with each other. Males typically grow larger than females. (2) In semiaquatic and “bottom-walking”

James F. Berry; Richard Shine

1980-01-01

234

Modeling habitat split: landscape and life history traits determine amphibian extinction thresholds.  

PubMed

Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance - the distance between the two required habitats - affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations. PMID:23818967

Fonseca, Carlos Roberto; Coutinho, Renato M; Azevedo, Franciane; Berbert, Juliana M; Corso, Gilberto; Kraenkel, Roberto A

2013-01-01

235

Habitat expansion and contraction in anchovy and sardine populations  

NASA Astrophysics Data System (ADS)

We investigated the relationships between stock biomass, distribution area and mean density of sardine and anchovy populations off California, Peru, South Africa and Japan. Our objective was to elucidate whether their ecological responses to habitat availability and use would support the possibility of them developing synchronic, alternating biomass fluctuations. Results indicate that as populations of both species grow in size, both the area they occupy and their packing density increase, generally consistent with the basin model. The relationship between distribution area and stock biomass is allometric, which implies that there is a limit to the stock expansion to new areas. Patterns of space occupation appear to differ between sardine and anchovy in some regions. In South Africa and Japan anchovy occupies larger area per unit biomass than sardine, consistent with habitat requirements as determined by their feeding ecology. Off California and Peru results confirm that in general species expand their distribution area with stock size, but specific patterns are less clear. Reasons for this are discussed, including sampling biases, the role of upwelling in limiting anchovy’s habitat off Peru, the ability of sardine to use offshore habitats off California, as well as possible differential space occupation patterns during population growth and decline. It is suggested that habitat availability may not be a pre-requisite for sardine growth in some areas, while anchovy may require habitat to become available for populations to grow. The differential habitat dependency and use of space between both species suggests that they cannot be considered to ecologically replace each other. While differences in space utilization may provide opportunities for diverging population paths, the ecological mechanisms behind out-of-phase fluctuations may be much more complex than a simple replacement. The results provide the first comparative, quantitative estimates of biomass/area relationships for pelagic fish, of use in models investigating the potential for expansion and contraction of anchovy and sardine populations worldwide based on climate change-driven habitat predictions.

Barange, Manuel; Coetzee, Janet; Takasuka, Akinori; Hill, Kevin; Gutierrez, Mariano; Oozeki, Yoshioki; Lingen, Carl van der; Agostini, Vera

2009-12-01

236

Partial gravity habitat study  

NASA Technical Reports Server (NTRS)

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.

Capps, Stephen; Lorandos, Jason; Akhidime, Eval; Bunch, Michael; Lund, Denise; Moore, Nathan; Murakawa, Kiosuke

1989-01-01

237

NOAA HABITAT BLUEPRINT Healthy habitats that sustain resilient and thriving marine  

E-print Network

NOAA HABITAT BLUEPRINT VISION Healthy habitats that sustain resilient and thriving marine · Recovered threatened and endangered species · Protected coastal and marine areas and habitats at risk · Resilient coastal communities · Increased coastal/marine tourism, access, and recreation PURPOSE The Habitat

238

Habitat Relations Habitat Modeling Used to Predict Relative  

E-print Network

(Lynx rufus) from bowhunters with remotely-sensed data to build models that describe habitat Information Systems (GIS), habitat model, Iowa, Lynx rufus, relative abundance. In the last few decades). Bobcats (Lynx rufus) are the most broadly distributed felid in North America and populations

Clark, William R.

239

SAGE-GROUSE NESTING AND BROOD HABITAT USE IN SOUTHERN CANADA  

Microsoft Academic Search

Greater sage-grouse (Centrocercus urophasianus )populations have declined from 6 6 to 92% during the las t 3 0 years in Canada, where they are listed as endangered. We used radiotelemetry to examine greater sage-grous e nest and brood habitat use in Alberta and assess the relationship between habitat and the population decline. W e also identified the patch size at

CAMERON L. ALDRIDGE

240

Measurement of the carrying capacity of benthic habitats using a metabolic-rate based index  

Microsoft Academic Search

Carrying capacities of grazed habitats are typically expressed as numbers or biomass of animals per unit area; however, such parameters are appropriate only when the body size of animals is constant because consumption and other metabolic-rate based parameters such as respiration and production are proportional to body mass raised by a power of ?0.75 rather than 0 or 1. Habitat

G. J. Edgar

1993-01-01

241

Drainage culverts as habitat linkages and factors affecting passage by mammals  

Microsoft Academic Search

Summary 1. Drainage culverts are ubiquitous features in road corridors, yet little is known about the efficacy of culverts for increasing road permeability and habitat connectivity for terrestrial wildlife. Culvert use by small- and medium-sized mammals was investigated along roads in Banff National Park, Alberta, Canada. An array of culvert types was sampled varying in dimensions, habitat and road features

Anthony P. Clevenger; Bryan Chruszcz; Kari Gunson

2001-01-01

242

ADEQUACY OF VISUALLY CLASSIFIED PARTICLE COUNT STATISTICS FROM REGIONAL STREAM HABITAT SURVEYS  

EPA Science Inventory

Streamlined sampling procedures must be used to achieve a sufficient sample size with limited resources in studies undertaken to evaluate habitat status and potential management-related habitat degradation at a regional scale. At the same time, these sampling procedures must achi...

243

Home range and habitat use of male ruffed grouse in managed mixed oak and aspen forests  

Microsoft Academic Search

Ruffed grouse (Bonasa umbellus) occupy many areas of the eastern and southeastern United States where oak (Quercus sp.) is the dominant forest type. However, most research on grouse habitat requirements and populations has taken place in Lake States aspen (Populus sp.) forests. We captured and radiotagged male grouse to determine spring and summer home range sizes and habitat use on

John E. McDonald; Gerald L. Storm; William L. Palmer

1998-01-01

244

Habitat Use by Fishes and Pacific Giant Salamanders in Small Western Oregon and Washington Streams  

Microsoft Academic Search

The habitat use patterns of juvenile salmonid fishes Oncorhynchus spp., Pacific giant salamanders Dicamptodon spp., torrent sculpins Cottus rhotheus, reticulate sculpins C. perplexus, and larval lampreys Entosphenus tridentatus and Lampetra spp. were examined in 30 small streams in western Oregon and Washington. Fish and salamander densities and sizes were compared between different habitat types (pools and riffles) in summer and

Philip Roni

2002-01-01

245

Numerically Exploring Habitat Fragmentation Effects on Populations Using Cell-Based Coupled Map Lattices  

Microsoft Academic Search

We examine habitat size, shape, and arrangement effects on populations using a discrete reaction–diffusion model. Diffusion is modeled passively and applied to a cellular grid of territories forming a coupled map lattice. Dispersal mortality is proportional to the amount of nonhabitat and fully occupied habitat surrounding a given cell, with distance decay. After verifying that our model produces the results

Michael Bevers; Curtis H. Flather

1999-01-01

246

Formulation of Habitat Suitability Models for Stream Fish Guilds: Do the Standard Methods Work?  

Microsoft Academic Search

Habitat suitability index (HSI) models for seven fish guilds in two segments of the upper Roanoke River drainage, Virginia, were formulated for the summer seasons of 1989 and 1990. We considered five habitat variables as potential limiting factors: depth, average and demersal velocities, average substratum size, and percent cover. These physical variables were modeled both separately and as composite HSI

Robert L. Vadas Jr; Donald J. Orth

2001-01-01

247

Using occupancy and population models to assess habitat conservation opportunities for an isolated carnivore population  

Microsoft Academic Search

An isolated population of the fisher (Martes pennanti) in the southern Sierra Nevada, California, is threatened by small size and habitat alteration from wildfires, fuels management, and other factors. We assessed the population’s status and conservation options for its habitat using a spatially explicit population model coupled with a fisher probability of occurrence model. The fisher occurrence model was selected

Wayne Spencer; Heather Rustigian-Romsos; James Strittholt; Robert Scheller; William Zielinski; Richard Truex

2011-01-01

248

Clay Animals and Their Habitats  

ERIC Educational Resources Information Center

Creating clay animals and their habitats with second-grade students has long been one of the author's favorite classroom activities. Students love working with clay and they also enjoy drawing animal homes. In this article, the author describes how the students created a diorama instead of drawing their clay animal's habitat. This gave students…

Adamson, Kay

2010-01-01

249

A Wildlife Habitat Improvement Plan.  

ERIC Educational Resources Information Center

The document presents an overview of Stony Acres, a "sanctuary" for wildlife as well as a place for recreation enjoyment and education undertakings. A review of the history of wildlife habitat management at Stony Acres and the need for continued and improved wildlife habitat management for the property are discussed in Chapter I. Chapter II…

Rogers, S. Elaine

250

Seafloor Geomorphology as Benthic Habitat  

E-print Network

#12;Seafloor Geomorphology as Benthic Habitat Peter T. Harris Senior Marine Science Advisor #12;Seafloor Geomorphology as Benthic Habitat. DOI: © 2012 Elsevier Inc. All rights reserved.2012 100058 58 Abstract We present the geomorphology of the Eastern Samoa Volcanic Province, covering 28,446km

Wright, Dawn Jeannine

251

Biodiversity and Wildlife Habitat Considerations for Opportunity  

E-print Network

1 Biodiversity and Wildlife Habitat Considerations for Opportunity Harvesting Prepared for considerations for biodiversity and wildlife habitat values during their development of a discussion paper paper. #12;2 A. INTRODUCTION When evaluating the biodiversity and wildlife habitat implications

252

Hydraulic and Habitat Suitability Analyses Technical Memorandum  

E-print Network

Appendix D Hydraulic and Habitat Suitability Analyses Technical Memorandum #12;COPYRIGHT DECEMBER Series 2 and Pond Series 3 Hydraulic and Habitat Suitability Analyses Prepared for Bureau of Reclamation HILL, INC. III Hydraulic and Habitat Suitability Analyses

253

Describing Willow Flycatcher habitats: scale perspectives and gender differences  

USGS Publications Warehouse

We compared habitat characteristics of nest sites (female-selected sites) and song perch sites (male-selected sites) with those of sites unused by Willow Flycatchers (Empidonax traillii) at three different scales of vegetation measurement: (1) microplot (central willow [Salix spp.] bush and four adjacent bushes); (2) mesoplot (0.07 ha); and, (3) macroplot (flycatcher territory size). Willow Flycatchers exhibited vegetation preferences at all three scales. Nest sites were distinguished by high willow density and low variability in willow patch size and bush height. Song perch sites were characterized by large central shrubs, low central shrub vigor, and high variability in shrub size. Unused sites were characterized by greater distances between willows and willow patches, less willow coverage, and a smaller riparian zone width than either nest or song perch sites. At all scales, nest sites were situated farther from unused sites in multivariate habitat space than were song perch sites, suggesting (1) a correspondence among scales in their ability to describe Willow Flycatcher habitat, and (2) females are more discriminating in habitat selection than males. Microhabitat differences between male-selected (song perch) and female-selected (nest) sites were evident at the two smaller scales; at the finest scale, the segregation in habitat space between male-selected and female-selected sites was greater than that between male-selected and unused sites. Differences between song perch and nest sites were not apparent at the scale of flycatcher territory size, possibly due to inclusion of (1) both nest and song perch sites, (2) defended, but unused habitat, and/or (3) habitat outside of the territory, in larger scale analyses. The differences between nest and song perch sites at the finer scales reflect their different functions (e.g., nest concealment and microclimatic requirements vs. advertising and territorial defense, respectively), and suggest that the exclusive use of either nest or song perch sites in vegetation analyses can result in misleading, or at least incomplete, descriptions of a species' habitat. Habitat interpretations for Willow Flycatchers (and perhaps for many passerines) are a function of the gender-specific behavior of the birds observed and the scale of vegetation measurement.

Sedgwick, James A.; Knopf, Fritz L.

1992-01-01

254

Campus Habitat Improvement Plan  

NSDL National Science Digital Library

In working with students to provide suitable habitat for species of interest, teachers can begin to develop the school campus into an outdoor classroom. Students will build self-esteem while obtaining useful real-life skills related to ecological practices. Students will have the opportunity to work with professionals from related fields of study. The hands-on activities give students a chance to put into practice the theories and themes that have been studied in a closed classroom setting. Students will learn to read aerial photographs, perform biological surveys, and write wildlife management plans. They will carry out management practices on the campus site and learn to evaluate the success of their program.

BEGIN:VCARD VERSION:2.1 FN:Francis Carter N:Carter; Francis ORG:Somerset High School REV:2005-04-15 END:VCARD

1995-06-30

255

Habitat Suitability Index Models: Pileated Woodpecker  

USGS Publications Warehouse

A review and synthesis of existing information was used to develop a habitat model for the pileated woodpecker (Dryocopus pileatus). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1 (optimally suitable habitat) for areas of the continental United States. Habitat suitability indexes are designed for use.with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

Schroeder, Richard L.

1983-01-01

256

Habitat Suitability Index Models: Baird's Sparrow  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a habitat model for Baird's sparrow. The model is scaled to produce an index of suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for Baird's sparrow habitat in the Northern Great Plains. Habitat suitability indices are designed for use with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

Sousa, Patrick J.; McDonal, W. Neil

1983-01-01

257

Habitat Suitability Index Models: Downy Woodpecker  

USGS Publications Warehouse

A review and synthesis of existing information was used to develop a habitat model for the downy woodpecker (Picoides eubescens). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1 (optimally suitable habitat) for areas of the continental United States. Habitat suitability indexes are designed for use with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

Schroeder, Richard L.

1983-01-01

258

Habitat expansion and contraction in anchovy and sardine populations  

Microsoft Academic Search

We investigated the relationships between stock biomass, distribution area and mean density of sardine and anchovy populations off California, Peru, South Africa and Japan. Our objective was to elucidate whether their ecological responses to habitat availability and use would support the possibility of them developing synchronic, alternating biomass fluctuations. Results indicate that as populations of both species grow in size,

Manuel Barange; Janet Coetzee; Akinori Takasuka; Kevin Hill; Mariano Gutierrez; Yoshioki Oozeki; Carl van der Lingen; Vera Agostini

2009-01-01

259

Responses of Bluegill to Habitat Manipulations: Power to Detect Effects  

Microsoft Academic Search

Power, the probability of detecting a particular effect of an experimental manipulation, has rarely been considered in whole-lake fishery experiments. We assessed the statistical power of experiments to detect effects of habitat manipulation on growth and population size of bluegills Lepomis macrochirus. In general, power was greater for detecting changes in growth increments than for population estimates. Power was greatest

S. R. Carpenter; P. Cunningham; S. Gafny; A. Munoz-Del-Rio; N. Nibbelink; M. Olson; T. Pellett; C. Storlie; A. Trebitz

1995-01-01

260

Tadpoles, Predation and Pond Habitats in the Tropics  

Microsoft Academic Search

Tadpoles involved in predator-prey interactions were studied in tropical wet forest in Costa Rica under laboratory and field conditions. Larvae of the frog Leptodactylus pentadactylus and naiads of the odonate Pantala flavescens are im- portant predators on larvae of several species of frogs. The predators discriminate the prey on the basis of size and species, but not type of habitat

W. Ronald Heyer; Roy W. McDiarmid; Diana L. Weigmann

1975-01-01

261

The population genetic consequences of habitat fragmentation for plants  

Microsoft Academic Search

Habitat fragmentation reduces the size and increases the spatial isolation of plant populations. Initial predictions have been that such changes will be accompanied by an erosion of genetic variation and increased interpopulation genetic divergence due to increased random genetic drift, elevated inbreeding and reduced gene flow. Results of recent empirical studies suggest that while genetic variation may decrease with reduced

Andrew Young; Tim Boyle; Tony Brown

1996-01-01

262

Habitat complexity: coral structural loss leads to fisheries declines.  

PubMed

Direct human impacts and global climate change are altering the composition and structure of coral reef habitats. These changes are simplifying size-abundance relationships of reef fish communities, reducing productivity through the system and ultimately threatening fisheries yields. PMID:24801184

Graham, Nicholas A J

2014-05-01

263

Life history strategy influences parasite responses to habitat fragmentation.  

PubMed

Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. Parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. We investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, Rhabdomys pumilio, in the Western Cape Province, South Africa. Our aim was to look at the effects of fragmentation on different parasite species with diverse life history characteristics and to determine whether general patterns can be found. Sampling took place within pristine lowland (Fynbos/Renosterveld) areas and at fragmented sites surrounded and isolated by agricultural activities. All arthropod ectoparasites and available gastrointestinal endoparasites were identified. We used conditional autoregressive models to investigate the effects of habitat fragmentation on parasite species richness and abundance of all recovered parasites. Host density and body size were larger in the fragments. Combined ecto- as well as combined endoparasite taxa showed higher parasite species richness in fragmented sites. Parasite abundance was generally higher in the case of R. pumilio individuals in fragmented habitats but it appears that parasites that are more permanently associated with the host's body and those that are host-specific show the opposite trend. Parasite life history is an important factor that needs to be considered when predicting the effects of habitat fragmentation on parasite and pathogen transmission. PMID:23954434

Froeschke, Götz; van der Mescht, Luther; McGeoch, Melodie; Matthee, Sonja

2013-12-01

264

Habitat Design Considerations for Implementing Solar Particle Event Radiation Protection  

NASA Technical Reports Server (NTRS)

Radiation protection is an important habitat design consideration for human exploration missions beyond Low Earth Orbit. Fortunately, radiation shelter concepts can effectively reduce astronaut exposure for the relatively low proton energies of solar particle events, enabling moderate duration missions of several months before astronaut exposure (galactic cosmic ray and solar particle event) approaches radiation exposure limits. In order to minimize habitat mass for increasingly challenging missions, design of radiation shelters must minimize dedicated, single-purpose shielding mass by leveraging the design and placement of habitat subsystems, accommodations, and consumables. NASA's Advanced Exploration Systems RadWorks Storm Shelter Team has recently designed and performed radiation analysis on several low dedicated mass shelter concepts for a year-long mission. This paper describes habitat design considerations identified during the study's radiation analysis. These considerations include placement of the shelter within a habitat for improved protection, integration of human factors guidance for sizing shelters, identification of potential opportunities for habitat subsystems to compromise on individual subsystem performances for overall vehicle mass reductions, and pre-configuration of shelter components for reduced deployment times.

Simon, Mathew A.; Clowdsley, Martha S.; Walker, Steven A.

2013-01-01

265

Avian habitat relationships in pinyon-juniper woodland  

USGS Publications Warehouse

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.

Sedgwick, James A.

1987-01-01

266

Habitat Suitability Index Models: Yellow Perch  

USGS Publications Warehouse

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.

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

1983-01-01

267

SALT MARSH HABITAT FROM A FISH EYE VIEW: A TEST OF THE DIMENSIONLESS INDEX OF HABITAT COMPLEXITY  

EPA Science Inventory

Salt marshes are considered important foraging and predator refuge areas for fish, but these functions are rarely measured. The goal of this study was to examine the relationship between the structural complexity of the habitat and fish size in marshes subjected to different wat...

268

Hiroshi Tomimatsu Masashi Ohara Evaluating the consequences of habitat fragmentation: a case study  

E-print Network

- ling recruitment being limited in smaller populations. This could be associated with edge effects altered micro- climatic conditions strongly limit seedling recruitment. Small populations also experienced Æ Population size Æ Seedling recruitment Introduction Destruction of natural habitat by humans leads

Tomimatsu,, Hiroshi

269

DIETARY OVERLAP IN FRUGIVOROUSAND INSECTIVOROUS BATS FROM EDAPHIC CERRADO HABITATS OF BRAZIL  

E-print Network

DIETARY OVERLAP IN FRUGIVOROUSAND INSECTIVOROUS BATS FROM EDAPHIC CERRADO HABITATS OF BRAZIL 79409-3131 Previous studies on size patterns within frugivorous and insectivorous bat guilds from (Glossophagasoricina, Sturnira lilium, Vampyropslineatus). Statistical anal- yses of insectivorous species produced

Willig, Michael

270

Life on the rocks: habitat use drives morphological and performance evolution in lizards.  

PubMed

As a group, lizards occupy a vast array of habitats worldwide, yet there remain relatively few cases where habitat use (ecology), morphology, and thus, performance, are clearly related. The best known examples include: increased limb length in response to increased arboreal perch diameter in anoles and increased limb length in response to increased habitat openness for some skinks. Rocky habitats impose strong natural selection on specific morphological characteristics, which differs from that imposed on terrestrial species, because moving about on inclined substrates of irregular sizes and shapes constrains locomotor performance in predictable ways. We quantified habitat use, morphology, and performance of 19 species of lizards (family Scincidae, subfamily Lygosominae) from 23 populations in tropical Australia. These species use habitats with considerable variation in rock availability. Comparative phylogenetic analyses revealed that occupation of rock-dominated habitats correlated with the evolution of increased limb length, compared to species from forest habitats that predominantly occupied leaf litter. Moreover, increased limb length directly affected performance, with species from rocky habitats having greater sprinting, climbing, and clinging ability than their relatives from less rocky habitats. Thus, we found that the degree of rock use is correlated with both morphological and performance evolution in this group of tropical lizards. PMID:19137951

Goodman, Brett A; Miles, Donald B; Schwarzkopf, Lin

2008-12-01

271

Simulated effects of habitat loss and fragmentation on a solitary, mustellid predator  

SciTech Connect

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 proportion 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.

Jager, Yetta [ORNL; Carr, Eric A [ORNL; Efroymson, Rebecca Ann [ORNL

2005-01-01

272

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

USGS Publications Warehouse

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.

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

1997-01-01

273

Risk of local extinction of Odonata freshwater habitat generalists and specialists.  

PubMed

Understanding the risk of a local extinction in a single population relative to the habitat requirements of a species is important in both theoretical and applied ecology. Local extinction risk depends on several factors, such as habitat requirements, range size of species, and habitat quality. We studied the local extinctions among 31 dragonfly and damselfly species from 1930 to 1975 and from 1995 to 2003 in Central Finland. We tested whether habitat specialists had a higher local extinction rate than generalist species. Approximately 30% of the local dragonfly and damselfly populations were extirpated during the 2 study periods. The size of the geographical range of the species was negatively related to extinction rate of the local populations. In contrast to our prediction, the specialist species had lower local extinction rates than the generalist species, probably because generalist species occurred in both low- and high-quality habitat. Our results are consistent with source-sink theory. PMID:24405332

Suhonen, Jukka; Korkeamäki, Esa; Salmela, Jukka; Kuitunen, Markku

2014-06-01

274

Habitat-Associations of Turban Snails on Intertidal and Subtidal Rocky Reefs  

PubMed Central

Patchiness of habitat has important influences on distributions and abundances of organisms. Given the increasing threat of loss and alteration of habitats due to pressures associated with humans, there is a need for ecologists to understand species' requirements for habitat and to predict changes to taxa under various future environmental conditions. This study tested hypotheses about the generality of patterns described for one species of marine intertidal turban snail for a different, yet closely-related species in subtidal habitats along the coast of New South Wales, Australia. These two closely-related species live in similar habitats, yet under quite different conditions, which provided an opportunity to investigate how similar types of habitats influence patterns of distribution, abundance and size-structure in intertidal versus subtidal environments. For each species, there were similar associations between biogenically structured habitat and densities. The intertidal species, Turbo undulates, were more abundant, with greater proportions of small individuals in habitats formed by the canopy-forming alga, Hormosira banksii, the solitary ascidian, Pyura stolonifera or the turfing red alga, Corallina officinalis compared to simple habitat (bare rock). Similarly, more Turbo torquatus were found in biogenically structured subtidal habitat, i.e. canopy-forming algae, Ecklonia radiata, mixed algal communities (‘fringe’), or turfing red algae (Corallina officinalis and Amphiroa aniceps) than where habitat is simple (barrens). Small T. torquatus were more abundant in areas of turf and ‘fringe’, while large snails were more abundant in areas of kelp and barrens. These patterns were found at each location sampled (i.e. eight intertidal and two subtidal rocky reefs) and at all times of sampling, across each environment. This study highlighted the consistent influence of biogenically structured habitats on the distribution, abundance and size-structure of intertidal and subtidal turban snails and forms a basis for increasing the understanding of the potential underlying processes causing such patterns. PMID:23675409

Smoothey, Amy F.

2013-01-01

275

Space habitat contaminant growth models.  

PubMed

This paper outlines the need for and role of Contaminant Growth Models (CGM) in designing space habitats and space mission operations. The tremendous complexity of the contamination problem and the current lack of data suggests that a "layered" approach to CGM development and utilization be made in conjunction with medical/toxicological research and risk assessments. Two space habitat contaminant examples: thermodegradation and hydrazine, are utilized to show how such a model might be useful in analyzing the environment of a space habitat. The examples also depict how NASA's interdisciplinary Center for Space Environmental Health (CSEH) will combine medical/toxicological research results with engineering environmental system design tools to set standards and help in the design, prediction, monitoring and safe control of space habitats. Since the CSEH project is just beginning, the contents of the paper are descriptive of the goal and the approach being taken, rather than conclusive in nature. PMID:11537567

Morgenthaler, G W; Kompala, D; Smith, G J; McAdams, T

1992-01-01

276

Habitat fragmentation and evolutionary ecology  

E-print Network

. Habitat fragmentation can be viewed of as a landscape-scale process involving two co-occurring components (Altizer et al. 2003). Another example of the evolutionary impact of human activity is the influence

Merckx, Thomas

277

Direct versus indirect effects of habitat fragmentation on community patterns in experimental landscapes.  

PubMed

Habitat area and fragmentation are confounded in many ecological studies investigating fragmentation effects. We thus devised an innovative experiment founded on fractal neutral landscape models to disentangle the relative effects of habitat area and fragmentation on arthropod community patterns in red clover (Trifolium pratense). The conventional approach in experimental fragmentation studies is to adjust patch size and isolation to create different landscape patterns. We instead use fractal distributions to adjust the overall amount and fragmentation of habitat independently at the scale of the entire landscape, producing different patch properties. Although habitat area ultimately had a greater effect on arthropod abundance and diversity in this system, we found that fragmentation had a significant effect in clover landscapes with ?40 % habitat. Landscapes at these lower habitat levels were dominated by edge cells, which had fewer arthropods and lower richness than interior cells. Fragmentation per se did not have a direct effect on local-scale diversity, however, as demonstrated by the lack of a broader landscape effect (in terms of total habitat area and fragmentation) on arthropods within habitat cells. Fragmentation-through the creation of edge habitat-thus had a strong indirect effect on morphospecies richness and abundance at the local scale. Although it has been suggested that fragmentation should be important at low habitat levels (?20-30 %), we show that fragmentation per se is significant only at intermediate (40 %) levels of habitat, where edge effects were neither too great (as at lower levels of habitat) nor too weak (as at higher levels of habitat). PMID:22526941

With, Kimberly A; Pavuk, Daniel M

2012-10-01

278

Habitat classification modeling with incomplete data: pushing the habitat envelope.  

PubMed

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 bb used. Traditional techniques generate pseudo-absence 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, threshold-independent receiver operating characteristic (ROC) plots, adjusted deviance (D(adj)2), 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 that incorporating biological knowledge into pseudo-absence point generation is a powerful tool for species habitat assessments. Furthermore, given some a priori knowledge of the species-habitat relationship, ecologically based pseudo-absence points can be applied to any species, ecosystem, data resolution, and spatial extent. PMID:17913135

Zarnetske, Phoebe L; Edwards, Thomas C; Moisen, Gretchen G

2007-09-01

279

Climate Change Action Pack Climate & Habitats  

E-print Network

Climate Change Action Pack Climate & Habitats B A C K G R O U DN C H E C K ! Habitat, Food, Water Change on habitats,and in particular at the impacts that could result from the warming of global the potential to affect plants,animals and humans around the globe. #12;Climate Change Action Pack 158 Habitat

Gunawardena, Arunika

280

SHORELINE, LAKE, AND ESTUARY SCALE HABITAT RESEARCH  

EPA Science Inventory

Habitat alteration is well recognized as a major cause of loss of living aquatic resources. Many fish and wildlife species depend on several habitats (or on habitat landscapes) in their life histories and migratory patterns. This NHEERL habitat research will develop stressor-re...

281

Predation, body size, and composition of plankton  

E-print Network

species is a "keystone predator" Oppose why the human species is a "keystone predator" Try Predator Alosa #12;Methods Measure frequency of 18 species of zooplankton (of different sizes) within 9 herbivores to dominate #12;Species sharing habitat allocate food by size according to their phenotypes Where

Jodice, Patrick

282

Geopressured habitat: A literature review  

SciTech Connect

A literature review of the geopressured-geothermal habitat is summarized. Findings are presented and discussed with respect to the principal topics: Casual agents are both geological and geochemical; they include disequilibrium compaction of sediments, clay diagenesis, aquathermal pressuring, hydrocarbon generation, and lateral tectonic compression. The overall physical and chemical characteristics of the habitats are dictated by varying combinations of sedimentation rates, alteration mineralogy, permeability, porosity and pressure, temperature, fluid content and chemistry, and hydrodynamic flow. Habitat pressure seals are considered in terms of their formation processes, geologic characteristics, and physical behavior, including pressure release and reservoir pressure recharge on a geologic time scale. World-wide occurrence of geopressured-geothermal habitats is noted. The main thrust of this topic concerns the U.S.A. and Canada; in addition, reference is made to occurrences in China and indications from deep-sea vents, as well as the contribution of paleo-overpressure to habitat initiation and maintenance. Identification and assessment of the habitat is addressed in relation to use of hydrogeologic, geophysical, geochemical, and geothermic techniques, as well as well-logging and drill-stem-test data. Conclusions concerning the adequacy of the current state of knowledge and its applicability to resource exploration and development are set forth, together with recommendations for the thrust of future work.

Negus-de Wys, Jane

1992-09-01

283

Habitat Suitability Index Models: Bigmouth Buffalo  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for Bigmouth buffalo (Ictiobus cyprinellus), a freshwater fish. The models are scaled to produce an indices of habitat suitability between 0 (unsuitable habitat) and 1 (optimally suitable habitat) for freshwater areas of the continental United States. Other habitat suitability models found in the literature are also included. Habitat suitability indices (HSI's) are designed for use with the habitat evaluation procedures developed by the U.S. Fish and Wildlife Service.

Edwards, Elizabeth A.

1983-01-01

284

Habitat Suitability Index Models: Black Brant  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a habitat suitability index model for wintering habitat of the black brant (Branta bernicla nigracans). The model consolidates habitat use information into a framework appropriate for field application and is scaled to produce an index value between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). Habitat suitability index (HSI) models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

Schroeder, Richard L.

1984-01-01

285

Habitat Suitability Index Models: Common Shiner  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for common shiner (Notropis cornutus). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for the northeastern range of the common shiner in North America. 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 smallmouth bass habitat.

Trial, Joan G.; Wade, Charles S.; Stanley, Jon G.; Nelson, Patrick C.

1983-01-01

286

Habitat Suitability Index Models: Eastern Brown Pelican  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a habitat model for the eastern brown pelican (Pelecanus occidentalis carolinensis). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimal habitat) for coastal areas within the eastern brown pelican's breeding range. 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 eastern brown pelican habitat model and techniques for measuring model variables are described.

Hingtgen, Terrence M.; Mulholland, Rosemarie; Zale, Alexander V.

1985-01-01

287

Asotin Creek Instream Habitat Alteration Projects: 1998 Habitat Evaluation Surveys.  

SciTech Connect

The Asotin Creek Model Watershed Master Plan was completed 1994. The plan was developed by a landowner steering committee for the Asotin County Conservation District (ACCD), with technical support from the various Federal, State and local entities. Actions identified within the plan to improve the Asotin Creek ecosystem fall into four main categories, (1) Stream and Riparian, (2) Forestland, (3) Rangeland, and (4) Cropland. Specific actions to be carried out within the stream and in the riparian area to improve fish habitat were, (a) create more pools, (b) increase the amount of large organic debris (LOD), (c) increase the riparian buffer zone through tree planting, and (d) increase fencing to limit livestock access; additionally, the actions are intended to stabilize the river channel, reduce sediment input, and protect private property. Fish species of main concern in Asotin Creek are summer steelhead (Oncorhynchus mykiss), spring chinook (Oncorhynchus tshawytscha), and bull trout (Salvelinus confluentus). Spring chinook in Asotin Creek are considered extinct (Bumgarner et al. 1998); bull trout and summer steelhead are below historical levels and are currently as ''threatened'' under the ESA. In 1998, 16 instream habitat projects were planned by ACCD along with local landowners. The ACCD identified the need for a more detailed analysis of these instream projects to fully evaluate their effectiveness at improving fish habitat. The Washington Department of Fish and Wildlife's (WDFW) Snake River Lab (SRL) was contracted by the ACCD to take pre-construction measurements of the existing habitat (pools, LOD, width, depth, etc.) within each identified site, and to eventually evaluate fish use within these sites. All pre-construction habitat measurements were completed between 6 and 14 July, 1998. 1998 was the first year that this sort of evaluation has occurred. Post construction measurements of habitat structures installed in 1998, and fish usage evaluation, will be conducted in 1999. As such, this report is confined to 1998 habitat data summaries for each site, with no analytical evaluation.

Bumgarner, Joseph D.

1999-03-01

288

Habitat Suitability Index Models: Gray Partridge  

USGS Publications Warehouse

This report is part of the Habitat Suitability Index model series which provides habitat information useful for impact assessment and habitat management. The Habitat Use Information section is largely constrained to those data that can be used to derive quantitative relationships between key environmental variables and habitat suitability. The habitat use information provides the foundation for the HSI model that follows. In addition, this same information may be useful in the development of other models more appropriate to specific assessment or evaluation needs for the gray partridge (Perdix perdix). The HSI model section documents a habitat model and information pertinent to its application. The model synthesizes the habitat use information into a framework appropriate for field application and is scaled to produce an index value between 0.0 (unsuitable habitat) and 1.0 (optimum habitat).

Allen, Arthur W.

1984-01-01

289

Perte d'habitat Dfinitions; Effets de la perte d'habitat sur la biodiversit;  

E-print Network

Perte d'habitat Définitions; Effets de la perte d'habitat sur la biodiversité; Relations aire, exploitation et altération des habitats naturels sont des conséquences de la croissance de la population humaine Perte d'habitat/ Risque d'extinction Croissancepopulationhumaine Élevé Faible Perte d'habitat

Blouin-Demers, Gabriel

290

The Habitat Assessment Model: A Tool to Improve Wildlife Habitat Management  

E-print Network

The Habitat Assessment Model: A Tool to Improve Wildlife Habitat Management G. Wockner1 , R. Boone1 the Habitat Partnership Program, to this project. The North Park Habitat Partnership Committee also contributed valuable time and effort through their work as a pilot study site for the Habitat Model. We thank

Boone, Randall B.

291

HABITAT HETEROGENEITY, HABITAT ASSOCIATIONS, AND RODENT SPECIES DIVERSITY IN A SAND–SHINNERY-OAK LANDSCAPE  

Microsoft Academic Search

The habitat-heterogeneity hypothesis states that an increase in habitat heterogeneity leads to an increase in species diversity. Although community-level analyses of effects of habitat heterogeneity on species diversity are important, they do not reveal the mechanism through which heterogeneity affects diversity. In contrast, habitat associations of particular species suggest a potential mechanism whereby diversity is affected by habitat heterogeneity. The

Michael J. Cramer; Michael R. Willig

2002-01-01

292

Habitat Suitability Index Models: Lark Bunting  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the lark bunting (Calamospiza melanocorys). 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.

Finch, Deborah M.; Anderson, Stanley H.; Hubert, Wayne A.

1987-01-01

293

Habitat Suitability Index Models: Smallmouth Buffalo  

USGS Publications Warehouse

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 Smallmouth buffalo (Ictiobus bubalus) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Edwards, Elizabeth A.; Twomey, Katie

1982-01-01

294

Habitat Suitability Index Models: Hairy Woodpecker  

USGS Publications Warehouse

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.

Sousa, Patrick J.

1987-01-01

295

Habitat Suitability Index Models: Greater Sandhill Crane  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the greater sandhill crane (Grus canadensis tabida). 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.

Armbruster, Michael J.

1987-01-01

296

Habitat Suitability Index Models: Flathead Catfish  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the flathead catfish (Pylodictis olivaris). 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.

Lee, Lawrence A.; Terrell, James W.

1987-01-01

297

Habitat Suitability Index Models: Black Bullhead  

USGS Publications Warehouse

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 Black bullhead (Ictalurus melas) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Stuber, Robert J.

1982-01-01

298

Habitat Suitability Index Models: American Coot  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the American coot (Fulica americana). The model consolidates habitat use information in to 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.

Allen, Arthur W.

1985-01-01

299

Habitat Suitability Index Models: Blue Grouse  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the blue grouse (Dendragapus obscurus). 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.

Schroeder, Richard L.

1984-01-01

300

Habitat Suitability Index Models: Eastern Meadowlark  

USGS Publications Warehouse

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.

Schroeder, Richard L.; Sousa, Patrick J.

1982-01-01

301

Habitat Suitability Index Models: Lesser Scaup (Breeding)  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the lesser scaup (Aythya affinis). 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.

Allen, Arthur W.

1986-01-01

302

Habitat Suitability Index Models: Brown Thrasher  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the brown thrasher (Toxostoma rufum). 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.

Cade, Brian S.

1986-01-01

303

Habitat Suitability Index Models: Eastern Wild Turkey  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the eastern wild turkey (Meleagris gallopavo sylvestris). 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.

Schroeder, Richard L.

1985-01-01

304

Habitat Suitability Index Models: Belted Kingfisher  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the belted kingfisher (Ceryle alcyon). 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.

Prose, Bart L.

1985-01-01

305

Habitat Suitability Index Models: Least Tern  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the least tern (Sterna antillarum). 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.

Carreker, Raymond G.

1985-01-01

306

Habitat Suitability Index Models: Barred Owl  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the barred owl (Strix varia). 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.

Allen, Arthur W.

1987-01-01

307

Habitat Suitability Index Models: Gadwall (Breeding)  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the gadwall (Anas strepera). 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.

Sousa, Patrick J.

1985-01-01

308

Habitat Suitability Index Models: Green Sunfish  

USGS Publications Warehouse

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 Green sunfish (Lepomis cyanellus) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Stuber, Robert J.; Gebhart, Glen; Maughan, O. Eugene

1982-01-01

309

Habitat Suitability Index Models: American Woodcock (Wintering)  

USGS Publications Warehouse

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

Cade, Brian S.

1985-01-01

310

Habitat Suitability Index Models: Gray Squirrel  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the gray squirrel (Sciurus carolinensis). 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 U.S. Fish and Wildlife Service.

Allen, Arthur W.

1987-01-01

311

Habitat Suitability Index Models: Common Carp  

USGS Publications Warehouse

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 Common carp (Cyprinus carpio) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Edwards, Elizabeth A.; Twomey, Katie

1982-01-01

312

Habitat Suitability Index Models: Snapping Turtle  

USGS Publications Warehouse

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.

Graves, Brent M.; Anderson, Stanley H.

1987-01-01

313

Habitat Suitability Index Models: Slider Turtle  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the slider turtle (Pseudemys scripta). 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.

Morreale, Stephen J.; Gibbons, J. Whitfield

1986-01-01

314

Habitat Suitability Index Models: Cactus Wren  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the cactus wren (Campylorhynchus brunneicapillus). 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.

Short, Henry L.

1985-01-01

315

Habitat Suitability Index Models: Largemouth Bass  

USGS Publications Warehouse

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 Largemouth bass (Micropterus salmoides) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Stuber, Robert J.; Gebhart, Glen; Maughan, O. Eugene

1982-01-01

316

Ontogenetic and diel variation in stream habitat use by brook trout (Salvelinus fontinalis) in a headwater stream  

USGS Publications Warehouse

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.

Johnson, J.H.; Ross, R.M.; Dropkin, D.S.; Redell, L.A.

2011-01-01

317

A genetic and morphometric comparison of Helisoma trivolvis and Gambusia holbrooki from clean and contaminated habitats.  

PubMed

Genetic and morphometric data from freshwater snail (Helisoma trivolvis) and mosquitofish (Gambusia holbrooki) populations from a relatively clean and a severely contaminated habitat were compared. Within the clean habitat, snail genetic patterns may have been more influenced than those of mosquitofish by site-specific selection because of the lesser likelihood of gene flow among snail subpopulations. Distinct genetic patterns within the contaminated habitat, combined with data from other published work, suggest that selection for tolerant genotypes may have occurred in both species. Body size in both species was associated with glucosephosphate isomerase allozyme genotype. In snails, apparent selection for a particular allele in the contaminated habitat may be related to its contaminant tolerance and body-size plasticity. In mosquitofish, a particular genotype associated with small body size appears to have been favored in the contaminated environment. PMID:7529161

Benton, M J; Diamond, S A; Guttman, S I

1994-10-01

318

Coefficients of Productivity for Yellowstone's Grizzly Bear Habitat  

USGS Publications Warehouse

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.

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

2004-01-01

319

A GIS modeling method applied to predicting forest songbird habitat  

USGS Publications Warehouse

We have developed an approach for using a??presencea?? data to construct habitat models. Presence data are those that indicate locations where the target organism is observed to occur, but that cannot be used to define locations where the organism does not occur. Surveys of highly mobile vertebrates often yield these kinds of data. Models developed through our approach yield predictions of the amount and the spatial distribution of good-quality habitat for the target species. This approach was developed primarily for use in a GIS context; thus, the models are spatially explicit and have the potential to be applied over large areas. Our method consists of two primary steps. In the first step, we identify an optimal range of values for each habitat variable to be used as a predictor in the model. To find these ranges, we employ the concept of maximizing the difference between cumulative distribution functions of (1) the values of a habitat variable at the observed presence locations of the target organism, and (2) the values of that habitat variable for all locations across a study area. In the second step, multivariate models of good habitat are constructed by combining these ranges of values, using the Boolean operators a??anda?? and a??or.a?? We use an approach similar to forward stepwise regression to select the best overall model. We demonstrate the use of this method by developing species-specific habitat models for nine forest-breeding songbirds (e.g., Cerulean Warbler, Scarlet Tanager, Wood Thrush) studied in southern Ohio. These models are based on speciesa?? microhabitat preferences for moisture and vegetation characteristics that can be predicted primarily through the use of abiotic variables. We use slope, land surface morphology, land surface curvature, water flow accumulation downhill, and an integrated moisture index, in conjunction with a land-cover classification that identifies forest/nonforest, to develop these models. The performance of these models was evaluated with an independent data set. Our tests showed that the models performed better than random at identifying where the birds occurred and provided useful information for predicting the amount and spatial distribution of good habitat for the birds we studied. In addition, we generally found positive correlations between the amount of habitat, as predicted by the models, and the number of territories within a given area. This added component provides the possibility, ultimately, of being able to estimate population sizes. Our models represent useful tools for resource managers who are interested in assessing the impacts of alternative management plans that could alter or remove habitat for these birds.

Dettmers, Randy; Bart, Jonathan

1999-01-01

320

Conservation planning and monitoring avian habitat  

USGS Publications Warehouse

Migratory bird conservation plans should not only develop population goals, they also should establish attainable objectives for optimizing avian habitats. Meeting population goals is of paramount importance, but progress toward established habitat objectives can generally be monitored more easily than can progress toward population goals. Additionally, local or regional habitat objectives can be attained regardless of perturbations to avian populations that occur outside the geographic area covered by conservation plans. Assessments of current avian habitats, obtained from remotely sensed data, and the historical distribution of habitats should be used in establishing habitat objectives. Habitat planning and monitoring are best conducted using a geographic information system. Habitat objectives are assigned to three categories: maintaining existing habitat, restoring habitat, and creating new or alternative habitat. Progress toward meeting habitat objectives can be monitored through geographic information systems by incorporating georeferenced information on public lands, private lands under conservation easements, corporate lands under prescribed management, habitat restoration areas, and private lands under alternative management to enhance wildlife values. We recommend that the area and distribution of habitats within the area covered by conservation plans be reassessed from remotely sensed imagery at intervals appropriate to detect predicted habitat changes.

Twedt, D.J.; Loesch, C.R.

2000-01-01

321

Predictions and retrodictions of the hierarchical representation of habitat in heterogeneous environments  

USGS Publications Warehouse

Interaction between habitat and species is central in ecology. Habitat structure may be conceived as being hierarchical, where larger, more diverse, portions or categories contain smaller, more homogeneous portions. When this conceptualization is combined with the observation that species have different abilities to relate to portions of the habitat that differ in their characteristics, a number of known patterns can be derived and new patterns hypothesized. We propose a quantitative form of this habitat–species relationship by considering species abundance to be a function of habitat specialization, habitat fragmentation, amount of habitat, and adult body mass. The model reproduces and explains patterns such as variation in rank–abundance curves, greater variation and extinction probabilities of habitat specialists, discontinuities in traits (abundance, ecological range, pattern of variation, body size) among species sharing a community or area, and triangular distribution of body sizes, among others. The model has affinities to Holling's textural discontinuity hypothesis and metacommunity theory but differs from both by offering a more general perspective. In support of the model, we illustrate its general potential to capture and explain several empirical observations that historically have been treated independently.

Kolasa, Jurek; Allen, Craig R.; Sendzimir, Jan; Stow, Craig A.

2012-01-01

322

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

USGS Publications Warehouse

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.

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

2009-01-01

323

Habitat use affects morphological diversification in dragon lizards  

PubMed Central

Habitat use may lead to variation in diversity among evolutionary lineages because habitats differ in the variety of ways they allow for species to make a living. Here, we show that structural habitats contribute to differential diversification of limb and body form in dragon lizards (Agamidae). Based on phylogenetic analysis and ancestral state reconstructions for 90 species, we find that multiple lineages have independently adopted each of four habitat use types: rock-dwelling, terrestriality, semi-arboreality and arboreality. Given these reconstructions, we fit models of evolution to species’ morphological trait values and find that rock-dwelling and arboreality limit diversification relative to terrestriality and semi-arboreality. Models preferred by Akaike information criterion infer slower rates of size and shape evolution in lineages inferred to occupy rocks and trees, and model-averaged rate estimates are slowest for these habitat types. These results suggest that ground-dwelling facilitates ecomorphological differentiation and that use of trees or rocks impedes diversification. PMID:20345808

COLLAR, D C; SCHULTE, J A; O’MEARA, B C; LOSOS, J B

2010-01-01

324

Integrating terrestrial laser scanning and repeat field measurements to quantify habitat changes during baseflow recession  

NASA Astrophysics Data System (ADS)

Understanding stream habitat heterogeneity is essential for evaluating stream habitat quality for salmonids, but the variability in pool sizes, groundwater sources, and the associated water quality makes characterization of habitat challenging. Habitat volume and stream connectivity are key drivers of ecosystem processes in spatially-intermittent streams, and strongly influence survival of juvenile salmonids in coastal California. Stream disconnection creates heterogeneous habitats, as disconnected pools are fed by distinct groundwater and hyporheic sources of water containing different concentrations of carbon, oxygen and nutrients. These distinct biogeochemical regimes drive production of benthic macroinvertebrates (salmonids' primary food source) and dissolved oxygen levels, which in turn govern salmonid metabolism. In this study, we use terrestrial laser scans of the streambed, topographic surveys of wetted pools, and repeat field measurements of pool depth to develop a timeseries of finely resolved pool volumes and dry riffle lengths. We overlay repeat water quality measurements onto this surface to visualize how cessation of flow creates heterogeneous habitats influenced by groundwater flux and geomorphic setting. By coupling terrestrial laser scans with traditional surveys, we create high-resolution facies surfaces that can be integrated with timeseries measurements of other biogeochemical data to characterize changes in habitat conditions during baseflow recession. Compared with traditional survey methods, this method yields improved qualitative descriptions of habitat fragmentation via visualizations and spatially and temporally explicit quantification of aquatic and riparian habitat characteristics that drive salmonid over-summer survival.

Woelfle-Erskine, C. A.; Thompson, S. E.

2013-12-01

325

eHabitat - A web service for habitat similarity modeling with uncertainty propagation  

NASA Astrophysics Data System (ADS)

We are developing eHabitat, a Web Processing Service (WPS) that can model current and future habitat similarity for point observations, polygons defining an existing or hypothetical protected area, or sets of polygons defining the estimated ranges for one or more species. A range of Web Clients makes it easy to use the WPS with predefined data for predictions of the current or future climatic niche. The WPS is also able to document propagating uncertainties of the input data to the estimated similarity maps, if such information is available. The presentation will focus on the architecture of the service and the clients, on how uncertainties are handled by the model and on the presentation of uncertain results. The idea behind eHabitat is that one can classify the similarity between a reference geometry (point locations or polygons) and the surroundings based on one or more species distribution models (SDMs) and a set of ecological indicators. The ecological indicators are typically raster bioclimatic data (DEMs, climate data, vegetation maps …) describing important features for the species or habitats of interest. All these data sets have uncertainties, which can usually be described by treating the value of each pixel as a mean with a standard deviation. As the standard deviation will also be pixel based, it can be given as rasters. If standard deviations of the rasters are not available in the input data, this can also be guesstimated by the service to allow end-users to generate uncertainty scenarios. Rasters of standard deviations are used for simulating a set of spatially correlated maps of the input data, which are then used in the SDM. Additionally, the service can do bootstrapping samples from the input data, which is one of the classic methods for assessing uncertainty of SDMs. The two methods can also be combined, a convenient solution considering that simulation is a computationally much slower process than bootstrapping. Uncertainties in the results produced by eHabitat can be visualized in different ways, as maps, as difference maps in the case of different SDMs, or as the uncertainty of summary statistics such as the habitat replaceability index (HRI) defined as the relative size of the area with a similarity to the training data above a certain threshold.

Olav Skøien, Jon; Schulz, Michael; Dubois, Gregoire; Heuvelink, Gerard

2013-04-01

326

Spatial Use by Wintering Greater White-Fronted Geese Relative to a Decade of Habitat Change in California's  

Microsoft Academic Search

We investigated the effect of recent habitat changes in California's Central Valley on wintering Pacific greater white-fronted geese (Anser albifrons frontalis) by comparing roost-to-feed distances, distributions, population range sizes, and habitat use during 1987-1990 and 1998- 2000. These habitat changes included wetland restoration and agricultural land enhancement due to the 1990 implementation of the Central Valley Joint Venture, increased land

JOSHUA T. ACKERMAN; JOHN Y. TAKEKAWA; DENNIS L. ORTHMEYER; JOSEPH P. FLESKES; JULIE L. YEE; KAMMIE L. KRUSE

327

Spatial Use by Wintering Greater White-Fronted Geese Relative to a Decade of Habitat Change in California's Central Valley  

Microsoft Academic Search

Abstract We investigated,the effect of recent,habitat changes,in California’s Central Valley on,wintering,Pacific greater,white-fronted,geese,(Anser albifrons frontalis) by comparing roost-to-feed distances, distributions, population range sizes, and habitat use during 1987–1990 and 1998– 2000. These habitat changes included wetland restoration and agricultural land enhancement,due to the 1990 implementation of the Central Valley Joint Venture, increased land area used for rice (Oryza sativa) production, and

JOSHUA T. ACKERMAN; JOHN Y. TAKEKAWA; DENNIS L. ORTHMEYER; JOSEPH P. FLESKES; JULIE L. YEE; KAMMIE L. KRUSE

2006-01-01

328

Concepts for manned lunar habitats  

NASA Technical Reports Server (NTRS)

The design philosophy that will guide the design of early lunar habitats will be based on a compromise between the desired capabilities of the base and the economics of its development and implantation. Preferred design will be simple, make use of existing technologies, require the least amount of lunar surface preparation, and minimize crew activity. Three concepts for an initial habitat supporting a crew of four for 28 to 30 days are proposed. Two of these are based on using Space Station Freedom structural elements modified for use in a lunar-gravity environment. A third concept is proposed that is based on an earlier technology based on expandable modules. The expandable modules offer significant advantages in launch mass and packaged volume reductions. It appears feasible to design a transport spacecraft lander that, once landed, can serve as a habitat and a stand-off for supporting a regolith environmental shield. A permanent lunar base habitat supporting a crew of twelve for an indefinite period can be evolved by using multiple initial habitats. There appears to be no compelling need for an entirely different structure of larger volume and increased complexity of implantation.

Hypes, W. D.; Butterfield, A. J.; King, C. B.; Qualls, G. D.; Davis, W. T.; Gould, M. J.; Nealy, J. E.; Simonsen, L. C.

1991-01-01

329

Deep Space Habitat Configurations Based on International Space Station Systems  

NASA Technical Reports Server (NTRS)

A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples, Dauphne; Miernik, Janie

2012-01-01

330

Deep Space Habitat Configurations Based On International Space Station Systems  

NASA Technical Reports Server (NTRS)

A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples,Dauphne; Miernik, Janie

2012-01-01

331

Habitat selection by breeding red-winged blackbirds  

USGS Publications Warehouse

Habitat preferences of breeding Red-winged Blackbirds in an agricultural area were determined by comparing population density, landscape characteristics, and vegetational descriptions. Observations were made throughout the breeding season. Preferred breeding habitats of Red-wings, in order of preference, were wetlands, hayfields, old fields, and pastures. Males and females occupied old fields and wetlands first, then hayfields, and finally, pastures. Cutting of hayfields caused territorial abandonment by both sexes within 48 h. The apparent movement of displaced females from cut hayfields to uncut hayfields suggests that habitat fidelity of females is strong after the breeding effort has begun. Breeding Red-wings exhibited general preferences for trees, large amounts of habitat edge, erect old vegetation, and sturdy, tall, and dense vegetation. Vegetative forms and species, such as upland grasses, broad- and narrow-leafed monocots in wetlands, and forbs were important to the Red-wing at various times during the breeding season. Landscape and vegetational preferences of breeding adults were easier to observe early in the breeding season (March through May) than later. Vegetational growth and increases in the size of the breeding population probably make these preferences more difficult to detect. Territory size was poorly correlated with landscape and vegetational characteristics in uplands but strongly correlated with broad- and narrow-leafed mono cots and vegetative height in wetlands. Wetland territories were smaller than upland territories. Territories increased in size during the middle and late portions of the breedi g season. Habitat selection by the Red-winged Blackbird can best be studied by evaluating vegetative preferences throughout the breeding season.

Albers, P.H.

1978-01-01

332

Habitat Suitability Index Models: Black Crappie  

USGS Publications Warehouse

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.

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

1982-01-01

333

Habitat Use and Spatial Relationships of American Alligator withHabitat Use and Spatial Relationships of American Alligator within Inland Wetlands of East Texasin Inland Wetlands of East Texas Introduction  

E-print Network

, sex, and size classes Methods During April-October 2006, alligators were captured at Brumley Lake neighbor and R statistics Classified habitat into shallow marsh, deep marsh, open water, islands, and human.05) was used to test for differences between capture location, habitat type and: · Sex (male, female

Hung, I-Kuai

334

Habitat Suitability Index Models: Clapper Rail  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a model suitable for evaluating the quality of coastal habitat of clapper rails (Rallus longirostris). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1 (optimally suitable habitat) for coastal areas of the continental United States. Habitat suitability indices are designed for use with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for clapper rail model applications and techniques for estimating model variables are discussed.

Lewis, James C.; Garrison, Russell L.

1983-01-01

335

Habitat Suitability Index Models: Laughing Gull  

USGS Publications Warehouse

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.

Zale, Alexander V.; Mulholland, Rosemarie

1985-01-01

336

Habitat Suitability Index Models: Juvenile Spot  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop estuarine habitat models for juvenile spot (Leiostomus xanthurus). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for estuarine areas of the continental 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. Guideline for juvenile spot model applications and techniques for estimating model variables are described.

Stickney, Robert R.; Cuenco, Michael L.

1982-01-01

337

Habitat Suitability Index Models Series  

NSDL National Science Digital Library

The US Geological Survey has just announced the availability of a series of HSI models by the US Fish and Wildlife Service. The HSI models are useful in conjunction with other habitat-based evaluation techniques (Habitat Evaluation Procedures and Instream Flow Incremental Methodology) in developing inventories, impact assessments, and fish and wildlife management plans. All models may be borrowed from Government Depository Libraries and/or the Department of the Interior (USFWS); information is provided at the site. HSI models are available for a range of species, from Alewife/Blueback Herrings to Yellow Warblers.

338

Surface soil physical and hydrological characteristics in Bromus tectorum L. (cheatgrass) versus Artemisia tridentata Nutt. (big sagebrush) habitat  

Microsoft Academic Search

Limited information exists of the differences in soil physical and hydrologic properties in invasive Bromus tectorum L. (BT) (cheatgrass) habitats versus native Artemisia tridentata Nutt. (AT) (big sagebrush) habitats. Our objective was to assess differences in soil physical and hydrological properties by comparing measures of soil particle size; aggregate stability; hydrophobicity; bulk density; penetration resistance; surface roughness; and infiltration (double-ring

J. Boxell; P. J. Drohan

2009-01-01

339

Is it possible to predict habitat use by spawning salmonids? A test using California golden trout ( Oncorhynchus mykiss aguabonita )  

Microsoft Academic Search

It is widely believed that stream salmonids select spawning sites based on water depth, water velocity, and substrate size. Attempts to predict spawning locations using these habitat features have met with little success, however. In this study, we used nonparametric logistic regression to determine what habitat features were associated with the locations chosen by spawning California golden trout (Oncorhynchus mykiss

Roland A. Knapp; Haiganoush K. Preisler

1999-01-01

340

Effects of Logging on Macroinvertebrate Responses to Watershed and Patch-Scale Habitat Characteristics in the Adirondack Uplands  

Microsoft Academic Search

Watershed characteristics and land use practices can affect stream habitats at a variety of scales. A suite of variables describing watershed geomorphology (area, circularity, slope, elevation, aspect, soil depth, surficial geology), surface water hydrology (drainage density, baseflow discharge, `flashiness', groundwater influx, water velocity), and channel habitat (slope, width, depth, substrate particle size, stored and transported organic matter, transported sediment) were

T. Woodcock; T. Mihuc; E. Romanowicz; E. Allen

2005-01-01

341

Effects of habitat fragmentation and road density on the distribution pattern of the moor frog Rana arvalis  

Microsoft Academic Search

1. The effects of habitat fragmentation on the distribution pattern of the moor frog Rana arvalis were investigated. Also, the possible isolation effects of the road network were taken into account. 2. Indications were found that habitat fragmentation partly explains the distribution pattern of the moor frog. The statistical models showed a positive effect of pond size (or marsh area)

C. C. Vos; P. Chardon

1998-01-01

342

Body size, colony size, abundance, and ecological impact of exotic ants  

E-print Network

workers relative to co-occurring native species? Do exotic ant species have a negative impact on the co-occurring in the context of biogeography (habitat, historical factors, co-occurring fauna) as models for successfulBody size, colony size, abundance, and ecological impact of exotic ants in Florida's upland

343

Systematic review of the influence of foraging habitat on red-cockaded woodpecker reproductive success.  

SciTech Connect

Relationships between foraging habitat and reproductive success provide compelling evidence of the contribution of specific vegetative features to foraging habitat quality, a potentially limiting factor for many animal populations. For example, foraging habitat quality likely will gain importance in the recovery of the threatened red-cockaded woodpecker Picoides borealis (RCW) in the USA as immediate nesting constraints are mitigated. Several researchers have characterized resource selection by foraging RCWs, but emerging research linking reproductive success (e.g. clutch size, nestling and fledgling production, and group size) and foraging habitat features has yet to be synthesized. Therefore, we reviewed peer-refereed scientific literature and technical resources (e.g. books, symposia proceedings, and technical reports) that examined RCW foraging ecology, foraging habitat, or demography to evaluate evidence for effects of the key foraging habitat features described in the species’ recovery plan on group reproductive success. Fitness-based habitat models suggest foraging habitat with low to intermediate pine Pinus spp. densities, presence of large and old pines, minimal midstory development, and herbaceous groundcover support more productive RCW groups. However, the relationships between some foraging habitat features and RCW reproductive success are not well supported by empirical data. In addition, few regression models account for > 30% of variation in reproductive success, and unstandardized multiple and simple linear regression coefficient estimates typically range from -0.100 to 0.100, suggesting ancillary variables and perhaps indirect mechanisms influence reproductive success. These findings suggest additional research is needed to address uncertainty in relationships between foraging habitat features and RCW reproductive success and in the mechanisms underlying those relationships.

Garabedian, James E. [North Carolina State University

2014-04-01

344

Living on the edge: Space use of Eurasian red squirrels in marginal high-elevation habitat  

NASA Astrophysics Data System (ADS)

In marginal habitats located at the edge of a species' range, environmental conditions are frequently extreme and individuals may be subject to different selective pressures compared to central populations. These so-called edge or marginal populations tend to have lower densities and reproductive rates than populations located in more suitable habitats, but little is known about local adaptations in spacing behavior. We studied space use and social organization in a population of Eurasian red squirrels ( Sciurus vulgaris) in a high-elevation marginal habitat of dwarf mountain pine ( Pinus mugo) and compared it with spacing patterns in high-quality Scots pine ( Pinus sylvestris) forest at lower-elevation. Home ranges and core areas were larger in the marginal habitat. In both habitats, males used larger home ranges than females, but sex differences in core area size were significant only in the edge population. Patterns of core area overlap were similar in both habitats with intra-sexual territoriality among adult females and higher degrees of inter-sexual overlap, typical for the species throughout its range. However, low densities in the edge population resulted in higher female by males overlap in spring-summer, suggesting males increased home ranges and core areas during mating season to augment access to estrus females. Thus, in the marginal habitat, with low food abundance and low population densities, linked with extreme winter conditions, squirrels, especially males, used large home ranges. Finally, squirrels responded more strongly to variation in food availability (inverse relation between home range size and seed abundance), and even to fluctuations in density (inverse relation between core area size and density of animals of the same sex), in the marginal than in the high-quality habitat, suggesting high behavioral plasticity to respond to the ecological constraints in marginal habitats.

Romeo, Claudia; Wauters, Lucas A.; Preatoni, Damiano; Tosi, Guido; Martinoli, Adriano

2010-11-01

345

Multiscale habitat selection by Ruffed Grouse at low population densities  

USGS Publications Warehouse

Theory suggests habitats should be chosen according to their relative evolutionary benefits and costs. It has been hypothesized that aspen (Populus spp.) forests provide optimal habitat for Ruffed Grouse (Bonasa umbellus). We used the low phase of a grouse population's cycle to assess the prediction that grouse should occupy aspen and avoid other forest types at low population density because of the presumptive fitness benefits of aspen. On the basis of our observations, we predict how the Ruffed Grouse population will increase in different forest types during the next cycle. In conifer (Pinus spp., Abies balsamea, Picea spp.)-dominated and mixed aspen-conifer landscapes, grouse densities were highest where forest types were evenly distributed. Within these landscapes, male Ruffed Grouse selected young aspen stands that were large and round or square. Although Ruffed Grouse selected young aspen stands strongly, contrary to prediction, they also used other forest types even when young aspen stands remained unoccupied. The relative densities of Ruffed Grouse in aspen and conifer forests indicated that the aspen forest's carrying capacities for grouse was higher than the conifer forest's at least during the low and declining phases of the grouse's cycle. On the basis of our observations, we predict that Ruffed Grouse populations in aspen-dominated landscapes will have higher population densities and fluctuate more than will populations in conifer-dominated landscapes. We suggest that studies of avian habitat selection would benefit from knowledge about the relative densities among habitats at differing population sizes because this information could provide insight into the role of habitat in regulating populations and clarify inferences from studies about habitat quality for birds. ?? 2009 by The Cooper Ornithological Society. All rights reserved.

Zimmerman, G.S.; Gutierrez, R.J.; Thogmartin, W.E.; Banerjee, S.

2009-01-01

346

Habitat use by Swainson's Warblers in a managed bottomland forest  

USGS Publications Warehouse

The Swainson's Warbler (Limnothlypis swainsonii) is a locally distributed and relatively uncommon Neotropical migrant songbird that breeds in the bottomland forests of the southeastern United States and spends the nonbreeding season in the Caribbean Basin. Populations of Swainson's Warblers have declined during recent decades as bottomland forests have come under increasingly intensive management and large areas have been converted to other land uses. We examined the habitat around song perches used by male Swainson's Warblers at Big Hammock Wildlife Management Area, a managed bottomland forest along the Altamaha River in Tattnall County, Georgia. We quantified 20 features of habitat structure in areas occupied by Swainson's Warblers (occupied plots) and two sets of controls: unoccupied plots adjacent to occupied plots (adjacent control plots) and unoccupied plots throughout the management area (general control plots). Occupied plots and adjacent control plots both differed in structure from the general control plots. We detected no significant differences, however, in vegetation structure between occupied plots and adjacent control plots. General control plots tended to have a greater number of trees, greater basal area, and a complete canopy, whereas occupied and adjacent control plots had high densities of small stems, cane, herbaceous ground cover, and leaf litter; this latter pattern is typical of documented Swainson's Warbler breeding habitat. Lack of significant differences in vegetation structure may be due to great variation in habitat structure around song perches, small sample size, or scarcity of Swainson's Warblers. Future research should focus on quantifying habitat characteristics around nest sites, song perches, and feeding areas. Our results suggest that management of bottomland habitats by thinning forests and encouraging regeneration of canebrakes is needed for successful conservation of Swainson's Warblers.

Somershoe, S.G.; Hudman, S.P.; Chandler, C.R.

2003-01-01

347

Using Dynamic Simulations and Automated Decision Tools to Design Lunar Habitats  

NASA Technical Reports Server (NTRS)

This paper describes the role of transient simulations, heuristic techniques, and closed loop integrated control in designing and sizing habitat life support systems. The integration of these three elements allows for more accurate requirements to be derived in advance of hardware choices. As a test case, we used a typical lunar surface habitat. Large numbers of habitat configurations were rapidly tested and evaluated using automated decision support tools. Through this process, preliminary sizing for habitat life support systems were derived. Our preliminary results show that by using transient simulations and closed loop control , we substantially reduced the system mass required to meet mission goals. This has greater implications for general systems analyses and for life support systems. It is likely that transient models, realtime integrated control, and other analyses capable of capturing the uncertainties of systems can be useful for systems analyses much earlier in the system development life cycle than has previously been considered.

Bell, Scott; Rodriguez, Luis; Kortenkamp, David

2005-01-01

348

Spawning Habitat Rehabilitation JOSEPH MICHAEL WHEATON  

E-print Network

i Spawning Habitat Rehabilitation By JOSEPH MICHAEL WHEATON B.S. (University of California, Davis J. Cech, Professor of Wildlife, Fisheries and Conservation Biology Committee in Charge 2003 #12;ii ................................................................................................................ 1 Spawning Habitat rehabilitation: Some Distinctions

Schladow, S. Geoffrey

349

FUTURE SCENARIOS OF CHANGE IN WILDLIFE HABITAT  

EPA Science Inventory

Studies in Pennsylvania, Iowa, California, and Oregon show varying losses of terrestrial wildlife habitat in scenarios based on different assumptions about future human land use patterns. Retrospective estimates of losses of habitat since Euro-American settlement in several stud...

350

Contributions of Estuarine Habitats to Major Fisheries  

EPA Science Inventory

Estuaries provide unique habitat conditions that are essential to the production of major fisheries throughout the world, but quantitatively demonstrating the value of these habitats to fisheries presents some difficult problems. The questions are important, because critical hab...

351

Campus Ecology: Habitat Restoration Projects  

NSDL National Science Digital Library

This website provides examples from over 40 campus landscaping projects from colleges across the US. Projects involved "green" practices such as reducing pesticide use, planting native vegetation, minimizing lawn space, removing pavement, or wildlife habitat restoration. The site also includes background information and tips for conducting campus environmental research, as well as links to additional resources.

National Wildlife Federation

352

MAINE ATLANTIC SALMON HABITAT - GENERAL  

EPA Science Inventory

ASDENN00 describes, at 1:24,000 scale, important Atlantic salmon habitat of the Dennys River in Maine. The coverage was developed from field surveys conducted on the Dennys River in Maine by staff of the Atlantic Salmon Authority and U.S. Fish and Wildlife Service. This survey wa...

353

Enchanted Learning: Biomes-Habitats  

NSDL National Science Digital Library

Created by Enchanted Learning, this kid-friendly Biome-Habitats website introduces children to many of the earth's biomes. Although the site provides basic information about many different biomes, the main emphasis is on the animals that live in each habitat. From the homepage, site visitors can link to almost twenty separate biome / habitat sites including Desert, Cave, Savanna, and Coral Reef-just too name a few. Each site presents a brief introduction covering general characteristics, such as plant life and climate, and then provides links to many separate animal pages ranging from grasshoppers to eagles. The animal pages feature nice diagrams (that can be printed out for coloring) and basic information about anatomy, diet and more. The Biome-Habitats homepage also contains a simple chart listing differences between biomes including elements such as amount of water, temperature range, and soil quality. (Note: While the site asks for a $20 / year donation, it is free to use and requires no registration or fee).

354

Prairie Dog and Habitat Activity  

NSDL National Science Digital Library

This activity allows students to make critical observations on free-ranging, feral animals and investigate their characteristics and habitat. This activity can be adapted to other forms of wildlife. Students will observe, record observations, categorize observations, key out plants, use sampling techniques, follow and devise a protocol, hypothesize, design experiments, conduct experiments, analyze data, and draw conclusions.

Tricia Kritzberger (Mitchell High School)

1996-07-01

355

Energetic considerations and habitat quality for elk in arid grasslands and coniferous forests  

SciTech Connect

The author used static modeling to explore the recent success of elk (Cervus elaphus) colonizing the arid shrub-steppe of Washington. Forage-based estimates of metabolizable energy available to elk in the shrub-steppe were compared to energy available in 2 mesic forest communities that historically have served as more typical summer elk habitat. Although precipitation and primary productivity were substantially lower in the shrub-steppe, the estimated calories available in shrub-steppe forage over a 300-km{sup 2} area were 271 and 86%, respectively, of lodgepole pine (Pinus contorta) and cedar-hemlock (Thuja-Tsuga) forests of similar size. Low intercommunity variability in forage production, lack of a significant nonforage overstory, and the large size and relative abundance of foraging areas in the shrub-steppe mitigated reduced primary production. In the shrub-steppe, 92% of the habitat represented potential foraging habitat as determined by minimum forage biomass, whereas only 10 and 40% of the forested habitats, respectively, could be considered prime foraging areas. Whereas forage energy was concentrated in openings within conifer forests, it was more uniformly dispersed over the habitat mosaic in the shrub-steppe. These results provide a bioenergetic framework for understanding the recent success of elk colonizing the arid shrub-steppe of Washington and are consistent with observed patterns of movement and habitat use for elk in shrub-steppe habitat.

McCorquodale, S.M. (Pacific Northwest Lab., Richland, WA (United States))

1991-04-01

356

Estimating functional connectivity of wildlife habitat and its relevance to ecological risk assessment  

USGS Publications Warehouse

Habitat fragmentation is a major threat to the viability of wildlife populations and the maintenance of biodiversity. Fragmentation relates to the sub-division of habitat intq disjunct patches. Usually coincident with fragmentation per se is loss of habitat, a reduction in the size of the remnant patches, and increasing distance between patches. Natural and anthropogenic processes leading to habitat fragmentation occur at many spatial scales, and their impacts on wildlife depend on the scales at which species interact with the landscape. The concept of functional connectivity captures this organism-based view of the relative ease of movement or degree of exchange between physically disjunct habitat patches. Functional connectivity of a given habitat arrangement for a given wildlife species depends on details of the organism's life history and behavioral ecology, but, for broad categories of species, quantities such as home range size and dispersal distance scale allometrically with body mass. These relationships can be incorporated into spatial analyses of functional connectivity, which can be quantified by indices or displayed graphically in maps. We review indices and GIS-based approaches to estimating functional connectivity, presenting examples from the literature and our own work on mammalian distributions. Such analyses can be readily incorporated within an ecological risk framework. Estimates of functional connectivity may be useful in a screening-level assessment of the impact of habitat fragmentation relative to other stressors, and may be crucial in detailed population modeling and viability analysis.

Johnson, A.R.; Allen, C.R.; Simpson, K.A.N.

2004-01-01

357

Habitat Use and Body Mass Regulation among Warblers in the Sahel Region during the Non-Breeding Season  

PubMed Central

Migratory birds face significant challenges across their annual cycle, including occupying an appropriate non-breeding home range with sufficient foraging resources. This can affect demographic processes such as over-winter survival, migration mortality and subsequent breeding success. In the Sahel region of Africa, where millions of migratory songbirds attempt to survive the winter, some species of insectivorous warblers occupy both wetland and dry-scrubland habitats, whereas other species are wetland or dry-scrubland specialists. In this study we examine evidence for strategic regulation of body reserves and competition-driven habitat selection, by comparing invertebrate prey activity-density, warbler body size and extent of fat and pectoral muscle deposits, in each habitat type during the non-breeding season. Invertebrate activity-density was substantially higher in wetland habitats than in dry-scrubland. Eurasian reed warblers Acrocephalus scirpaceus occupying wetland habitats maintained lower body reserves than conspecifics occupying dry-scrub habitats, consistent with buffering of reserves against starvation in food-poor habitat. A similar, but smaller, difference in body reserves between wet and dry habitat was found among subalpine warblers Sylvia cantillans but not in chiffchaffs Phylloscopus collybita inhabiting dry-scrub and scrub fringing wetlands. Body reserves were relatively low among habitat specialist species; resident African reed warbler A. baeticatus and migratory sedge warbler A. schoenobaenus exclusively occupying wetland habitats, and Western olivaceous warblers Iduna opaca exclusively occupying dry habitats. These results suggest that specialists in preferred habitats and generalists occupying prey-rich habitats can reduce body reserves, whereas generalists occupying prey-poor habitats carry an increased level of body reserves as a strategic buffer against starvation. PMID:25426716

Vafidis, James O.; Vaughan, Ian P.; Jones, T. Hefin; Facey, Richard J.; Parry, Rob; Thomas, Robert J.

2014-01-01

358

Habitat Use and Body Mass Regulation among Warblers in the Sahel Region during the Non-Breeding Season.  

PubMed

Migratory birds face significant challenges across their annual cycle, including occupying an appropriate non-breeding home range with sufficient foraging resources. This can affect demographic processes such as over-winter survival, migration mortality and subsequent breeding success. In the Sahel region of Africa, where millions of migratory songbirds attempt to survive the winter, some species of insectivorous warblers occupy both wetland and dry-scrubland habitats, whereas other species are wetland or dry-scrubland specialists. In this study we examine evidence for strategic regulation of body reserves and competition-driven habitat selection, by comparing invertebrate prey activity-density, warbler body size and extent of fat and pectoral muscle deposits, in each habitat type during the non-breeding season. Invertebrate activity-density was substantially higher in wetland habitats than in dry-scrubland. Eurasian reed warblers Acrocephalus scirpaceus occupying wetland habitats maintained lower body reserves than conspecifics occupying dry-scrub habitats, consistent with buffering of reserves against starvation in food-poor habitat. A similar, but smaller, difference in body reserves between wet and dry habitat was found among subalpine warblers Sylvia cantillans but not in chiffchaffs Phylloscopus collybita inhabiting dry-scrub and scrub fringing wetlands. Body reserves were relatively low among habitat specialist species; resident African reed warbler A. baeticatus and migratory sedge warbler A. schoenobaenus exclusively occupying wetland habitats, and Western olivaceous warblers Iduna opaca exclusively occupying dry habitats. These results suggest that specialists in preferred habitats and generalists occupying prey-rich habitats can reduce body reserves, whereas generalists occupying prey-poor habitats carry an increased level of body reserves as a strategic buffer against starvation. PMID:25426716

Vafidis, James O; Vaughan, Ian P; Jones, T Hefin; Facey, Richard J; Parry, Rob; Thomas, Robert J

2014-01-01

359

Stream Crayfish Distribution Patterns and Habitat Associations in northern Mississippi  

NASA Astrophysics Data System (ADS)

Distribution patterns and habitat associations of crayfishes in Mississippi are largely unexplored. During summers 1999-2003, we sampled crayfishes, fishes and habitat in 119 stream sites in northern Mississippi. We captured over 1,200 crayfish of 9 species from 3 genera. Species co-occurrence analyses and principal components analyses (PCA) of species abundances indicated significant species structuring among crayfish assemblages. We infer from co-occurrence patterns that both competitive interactions and historic processes led to present distributions. Mantel tests and PCA both indicated that crayfish assemblage characteristics are significantly related to stream size, but not to other habitat variables. In contrast to the nearly-universal rule for aquatic taxa that species richness increases with stream size, crayfish richness, abundance, and density were inversely related to stream size. Crayfish densities dropped precipitously when watershed area exceeded about 2,500 hectares. The low richness and abundance of crayfishes in medium and large streams may be due, in part, to the extreme disturbance from channelization and incisement in middle to lower reaches of most of the drainages we studied. Intermittent and very small perennial streams are sometimes regarded as biologically unimportant by land managers, but are primary strongholds of stream crayfishes in northern Mississippi.

Adams, S. B.; Warren, M. L.

2005-05-01

360

Effect of habitat area and isolation on fragmented animal populations  

PubMed Central

Habitat destruction has driven many once-contiguous animal populations into remnant patches of varying size and isolation. The underlying framework for the conservation of fragmented populations is founded on the principles of island biogeography, wherein the probability of species occurrence in habitat patches varies as a function of patch size and isolation. Despite decades of research, the general importance of patch area and isolation as predictors of species occupancy in fragmented terrestrial systems remains unknown because of a lack of quantitative synthesis. Here, we compile occupancy data from 1,015 bird, mammal, reptile, amphibian, and invertebrate population networks on 6 continents and show that patch area and isolation are surprisingly poor predictors of occupancy for most species. We examine factors such as improper scaling and biases in species representation as explanations and find that the type of land cover separating patches most strongly affects the sensitivity of species to patch area and isolation. Our results indicate that patch area and isolation are indeed important factors affecting the occupancy of many species, but properties of the intervening matrix should not be ignored. Improving matrix quality may lead to higher conservation returns than manipulating the size and configuration of remnant patches for many of the species that persist in the aftermath of habitat destruction. PMID:19073931

Prugh, Laura R.; Hodges, Karen E.; Sinclair, Anthony R. E.; Brashares, Justin S.

2008-01-01

361

Transport Infrastructure Shapes Foraging Habitat in a Raptor Community  

PubMed Central

Transport infrastructure elements are widespread and increasing in size and length in many countries, with the subsequent alteration of landscapes and wildlife communities. Nonetheless, their effects on habitat selection by raptors are still poorly understood. In this paper, we analyzed raptors’ foraging habitat selection in response to conventional roads and high capacity motorways at the landscape scale, and compared their effects with those of other variables, such as habitat structure, food availability, and presence of potential interspecific competitors. We also analyzed whether the raptors’ response towards infrastructure depends on the spatial scale of observation, comparing the attraction or avoidance behavior of the species at the landscape scale with the response of individuals observed in the proximity of the infrastructure. Based on ecological hypotheses for foraging habitat selection, we built generalized linear mixed models, selected the best models according to Akaike Information Criterion and assessed variable importance by Akaike weights. At the community level, the traffic volume was the most relevant variable in the landscape for foraging habitat selection. Abundance, richness, and diversity values reached their maximum at medium traffic volumes and decreased at highest traffic volumes. Individual species showed different degrees of tolerance toward traffic, from higher abundance in areas with high traffic values to avoidance of it. Medium-sized opportunistic raptors increased their abundance near the traffic infrastructures, large scavenger raptors avoided areas with higher traffic values, and other species showed no direct response to traffic but to the presence of prey. Finally, our cross-scale analysis revealed that the effect of transport infrastructures on the behavior of some species might be detectable only at a broad scale. Also, food availability may attract raptor species to risky areas such as motorways. PMID:25786218

Planillo, Aimara; Kramer-Schadt, Stephanie; Malo, Juan E.

2015-01-01

362

Home Range, Habitat Use, and Activity of Baird's Tapir in Costa Rica1  

Microsoft Academic Search

Home range size, habitat utilization, and activity patterns of five adult Baird's tapirs (Tapirus bairdii) were studied via radiotelemetry from June 1995 to May 1996 in Corcovado National Park, Costa Rica. Estimates of 4153 animal locations were made. Home range sizes (95% minimum convex polygon) for the entire study period (wet season and dry season) averaged 125.0 ha (SD 5

Charles R. Foerster; Christopher Vaughan

2002-01-01

363

Home Range and Habitat Use of Male Rafinesque's Big-Eared Bats (Corynorhinus rafinesquii)  

Microsoft Academic Search

We examined home range size and habitat use of four reproductively active male Rafinesque Big-eared bats in the upper Coastal Plain of South Carolina during August and September of 1999. Most foraging activity occurred during the first 4 hours after sunset and the first two hours before sunrise. Mean home range size was 93.1 hectares. Most foraging activity occurred in

M. A. Menzel; J. M. Menzel; W. M. Ford; J. W. Edwards; T. C. Carter; J. B. Churchill; J. C. Kilgo

2000-01-01

364

Habitat Suitability Index Models: Field Sparrow  

USGS Publications Warehouse

Habitat preferences of the field sparrow (Spizella pusilla) are described in this report, which is one of a series of Habitat Suitability Index (HSI) models. A review and synthesis of the literature is followed by the development of a habitat model for the field sparrow throughout its breeding range in the United States. HSI models are designed to be used in conjunction with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

Sousa, Patrick J.

1983-01-01

365

GHOSTS OF HABITATS PAST: CONTRIBUTION OF LANDSCAPE CHANGE TO CURRENT HABITATS USED BY SHRUBLAND BIRDS  

Microsoft Academic Search

Models of habitat associations for species often are developed with an im- plicit 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

STEVEN T. K NICK; JOHN T. R OTENBERRY

2000-01-01

366

The Habitat Conservation Division, Northeast Region is working to protect, conserve and restore habitats of our  

E-print Network

The Habitat Conservation Division, Northeast Region is working to protect, conserve and restore habitats of our living marine resources. Primary Activities The Habitat Conservation Division collaborates with regional fishery management councils to: Identify and describe Essential Fish Habitat (EFH) for each

367

Assessing critical habitat: Evaluating the relative contribution of habitats to population persistence  

Microsoft Academic Search

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 commonly used approaches to identify important habitats do not provide direct insight into the contribution of those habitats to population persistence. To assess how habitats contribute to overall population viability and characterize their relative importance,

Julie A. Heinrichs; Darren J. Bender; David L. Gummer; Nathan H. Schumaker

2010-01-01

368

Behavioral mechanisms of habitat segregation between sympatric species of Microtus : Habitat preference and interspecific dominance  

Microsoft Academic Search

Two species of microtine rodents are sympatric in eastern Washington, but they are segregated by habitat. Microtus montanus is found in the grass, and M. longicaudus occupies the shrub habitat. This investigation evaluated behavioral mechanisms controlling the distribution and asked the questions: (1) Are voles of either or both species occupying a preferred habitat? (2) Is a habitat preference influenced

Jan A. Randall

1978-01-01

369

Habitat Modeling Using Path Analysis: Delineating Mountain Goat Habitat in the Washington Cascades  

E-print Network

Habitat Modeling Using Path Analysis: Delineating Mountain Goat Habitat in the Washington Cascades: ______________________________________ #12;HABITAT MODELING USING PATH ANALYSIS: DELINEATING MOUNTAIN GOAT HABITAT IN THE WASHINGTON CASCADES in mountain goat (Oreamnos americanus) populations in Washington State over the past few decades has spurred

Wallin, David O.

370

Post-settlement Life Cycle Migration Patterns and Habitat Preference of Coral Reef Fish that use Seagrass and Mangrove Habitats as Nurseries  

NASA Astrophysics Data System (ADS)

Mangroves and seagrass beds have received considerable attention as nurseries for reef fish, but comparisons have often been made with different methodologies. Thus, relative importance of different habitats to specific size-classes of reef fish species remains unclear. In this study, 35 transects in 11 sites of mangroves, seagrass beds and coral reef were surveyed daily, in and in front of a marine bay on the island of Curaçao (Netherlands Antilles). The density and size-frequency of nine reef fish species (including herbivores, zoobenthivores and piscivores) was determined during a five-month period using a single methodology, viz. underwater visual census. All species were ' nursery species ' in terms of their high densities of juveniles in mangroves or seagrass beds. Relative density distribution of the size-classes of the selected species over mangroves and seagrass beds suggested high levels of preference for either mangroves or seagrass beds of some species, while other species used both habitats as a nursery. Spatial size distribution of the nine species suggested three possible models for Post-settlement Life Cycle Migrations (PLCM). Haemulon sciurus, Lutjanus griseus, L. apodus, and Acanthurus chirurgus appear to settle and grow up in bay habitats such as mangroves and seagrass beds, and in a later stage migrate to the coral reef (Long Distance PLCM). Juveniles of Acanthurus bahianus and Scarus taeniopterus were found only in bay habitats at close proximity to the coral reef or on the reef itself, and their migration pattern concerns a limited spatial scale (Short Distance PLCM). Some congeneric species carry out either Long Distance PLCM or Short Distance PLCM, thereby temporarily alleviating competition in reef habitats. Haemulon flavolineatum, Ocyurus chrysurus and Scarus iserti displayed a Stepwise PLCM pattern in which smallest juveniles dwell in the mouth of the bay, larger individuals then move to habitats deeper into the bay, where they grow up to a (sub-) adult size at which they migrate to nearby coral reef habitats. This type of stepwise migration in opposite directions, combined with different preference for either mangroves or seagrass beds among (size-classes of) species, shows that reef fish using in-bay habitats during post-settlement life stages may do so by choice and not merely because of stochastic dispersal of their larvae, and underline the necessity of these habitats to Caribbean coral reef systems.

Cocheret de la Morinière, E.; Pollux, B. J. A.; Nagelkerken, I.; van der Velde, G.

2002-08-01

371

Isolation of Novel Ultramicrobacteria Classified as Actinobacteria from Five Freshwater Habitats in Europe and Asia  

Microsoft Academic Search

We describe the first freshwater members of the class Actinobacteria that have been isolated. Nine ultrami- cro-size (<0.1 m3) strains were isolated from five freshwater habitats in Europe and Asia. These habitats represent a broad spectrum of ecosystems, ranging from deep oligotrophic lakes to shallow hypertrophic lakes. Even when the isolated strains were grown in very rich media, the cell

Martin W. Hahn; Heinrich Lunsdorf; Qinglong Wu; Michael Schauer; Manfred G. Hofle; Jens Boenigk; Peter Stadler

2003-01-01

372

A demographic analysis of vole population responses to fragmentation and destruction of habitat  

Microsoft Academic Search

Fragmentation and destruction of natural habitats is currently considered to be the major threat to wildlife populations.\\u000a We here perform a comprehensive analysis of the demographic effects of habitat fragmentation and destruction on 14 populations\\u000a of the root vole. The experiment was divided into two consecutive periods. During the first period, we contrasted populations\\u000a with the same initial size and

Edda Johannesen; Jon Aars; Harry P. Andreassen; Rolf A. Ims

2003-01-01

373

The effects of spatial habitat configuration on recruitment, growth and population structure in arctic Collembola  

Microsoft Academic Search

The population density and demography of five species of arctic Collembola were studied in a naturally patchy habitat, consisting\\u000a of Carex ursinae tussocks with varying degrees of isolation. Focal predictor variables were those describing the spatial configuration of\\u000a tussocks, including tussock size and isolation and the amount of habitat (cover) at a 1-m2 scale surrounding each tussock population. The Collembola

Karine Hertzberg; Nigel G. Yoccoz; Rolf A. Ims; Hans Petter Leinaas

2000-01-01

374

Size structure of the metazoan community in a Piedmont stream  

Microsoft Academic Search

We characterized the size structure of virtually the entire metazoan community in a fourth order, sandybottomed Piedmont stream during late summer. Our study, the first to sample across all habitat types and sizes of metazoans in an aquatic ecosystem, indicates that at the community level, stream size spectra may be bimodal for the benthos or trimodal when fish are included.

N. LeRoy Poff; Margaret A. Palmer; Paul L. Angermeier; Robert L. Vadas; Christine C. Hakenkamp; Alexa Bely; Peter Arensburger; Andrew P. Martin

1993-01-01

375

Habitat Fragmentation and Edge Effects Definition  

E-print Network

Consequences ·Case studies: ·East African Forest Fragments ·EDF Birds #12;#12;Habitat Fragmentation: Breaking up of habitat into smaller pieces More Specifically: ·Reduction in habitat area ·Decrease in patch Area Relationship #12;Species Area Relationship S=cAz number of species=intercept*area slope #12

Hansen, Andrew J.

376

Habitat and Wildlife Protection and Restoration  

E-print Network

Habitat and Wildlife Protection and Restoration funded by the Great Lakes Restoration Initiative The health of Great Lakes habitats and wildlife depends upon the protection and restoration of ecosystems. A multitude of threats affect the health of Great Lakes habitats and wildlife and many opportunities exist

377

GENERAL WILDLIFE HABITATS\\/VEGETATION COMMUNITIES  

Microsoft Academic Search

Ten wildlife habitats are present in the vicinity of the alternatives, including blue oak woodland, chamise-redshank chaparral, mixed chaparral, montane chaparral, annual grassland, montane hardwood, Sierran mixed conifer, agriculture, and urban. Maps illustrating the location and extent of each of these wildlife habitats are provided in Chapter 6. The diversity of wildlife found within each wildlife habitat is dependent on

CHAMISE-REDSHANK CHAPARRAL

378

EFFECTS OF HABITAT FRAGMENTATION ON BIODIVERSITY  

Microsoft Academic Search

? Abstract The literature on effects of habitat fragmentation on biodiversity is huge. It is also very diverse, with different authors measuring fragmentation in dif- ferent ways and, as a consequence, drawing different conclusions regarding both the magnitude and direction of its effects. Habitat fragmentation is usually defined as a landscape-scale process involving both habitat loss and the breaking apart

Lenore Fahrig

2003-01-01

379

JUVENILE BAY SCALLOP (ARGOPECTEN IRRADIANS) HABITAT PREFERENCES  

EPA Science Inventory

Habitat quality and quantity are known to be important for maintaining populations of bay scallops (Argopecten irradians), but data linking habitat attributes to bay scallop populations are lacking. This information is essential to understand the role of habitat alteration in th...

380

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

USGS Publications Warehouse

Increasing development and increasing water withdrawals for public, industrial, and agricultural water supply threaten to reduce streamflows in the Shenandoah River basin in Virginia. Water managers need more information to balance human water-supply needs with the daily streamflows necessary for maintaining the aquatic ecosystems. To meet the need for comprehensive information on hydrology, water supply, and instream-flow requirements of the Shenandoah River basin, the U.S. Geological Survey and the Northern Shenandoah Valley Regional Commission conducted a cooperative investigation of habitat availability during low-flow periods on the North Fork Shenandoah River. Historic streamflow data and empirical data on physical habitat, river hydraulics, fish community structure, and recreation were used to develop a physical habitat simulation model. Hydraulic measurements were made during low, medium, and high flows in six reaches at a total of 36 transects that included riffles, runs, and pools, and that had a variety of substrates and cover types. Habitat suitability criteria for fish were developed from detailed fish-community sampling and microhabitat observations. Fish were grouped into four guilds of species and life stages with similar habitat requirements. Simulated habitat was considered in the context of seasonal flow regimes to show the availability of flows that sustain suitable habitat during months when precipitation and streamflow are scarce. The North Fork Shenandoah River basin was divided into three management sections for analysis purposes: the upper section, middle section, and lower section. The months of July, August, and September were chosen to represent a low-flow period in the basin with low mean monthly flows, low precipitation, high temperatures, and high water withdrawals. Exceedance flows calculated from the combined data from these three months describe low-flow periods on the North Fork Shenandoah River. Long-term records from three 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

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

2006-01-01

381

Geomorphic, flood, and groundwater-flow characteristics of Bayfield Peninsula streams, Wisconsin, and implications for brook-trout habitat  

USGS Publications Warehouse

Available brook-trout habitat is dependent on the locations of groundwater upwellings, the sizes of flood peaks, and sediment loads. Management practices that focus on reducing or slowing runoff from upland areas a

Fitzpatrick, Faith A.; Peppler, Marie C.; Saad, David A.; Pratt, Dennis M.; Lenz, Bernard N.

2015-01-01

382

Effectiveness of voluntary habitat stewardship in conserving grassland: case of operation burrowing owl in Saskatchewan.  

PubMed

There have been no published performance evaluations of nongovernmental, voluntary habitat stewardship programs. The Operation Burrowing Owl (OBO) stewardship program, initiated in 1987, was evaluated for its effectiveness in conservation of grassland habitat during 1986-1993. The 108 OBO sites from 1987 to 88 and 98 randomly selected non-OBO sites that were grassland in 1986 in the Regina-Weyburn, Saskatchewan study area were classified by size and agricultural soil suitability. By 1993, 41 (38%) of the 108 OBO sites had been withdrawn from the program. The 1986 area of grassland was compared with grassland area calculated from digitized 1993 LANDSAT imagery. A correction for satellite inaccuracies was determined. Grassland retention in 1993 was significantly higher at OBO sites (66%) than at random sites (49%), demonstrating that the OBO voluntary program effectively conserved habitat. Also, grassland retention was significantly lower on sites with better agricultural soils, and for sites <12 ha in size. Site type (OBO or random), size and their interaction, followed by agricultural soil suitability, had the greatest effects on grassland retention. During an era of accelerated grassland loss, OBO strongly and positively (statistically significant) affected conservation of grassland sites most at risk: sites <12 ha in size and with good to excellent agricultural soils. This suggests that grassland conservation efforts focus on vulnerable sites (small size and/or good agricultural soils) to provide nesting habitat for burrowing owls. Our study demonstrates that a voluntary stewardship program can significantly increase conservation of habitat. PMID:15037954

Warnock, Robert G; Skeel, Margaret A

2004-03-01

383

Density-dependent habitat selection of spawning Chinook salmon: broad-scale evidence and implications.  

PubMed

An extensive body of theory suggests that density-dependent habitat selection drives many fundamental ecological processes. The ideal free distribution and the ideal despotic distribution make contrasting predictions about the effect of total population size on relative abundances among habitats. Empirical assessment of these habitat selection models is uncommon because data must be collected over large temporal and spatial scales. I ask whether fluctuation in Chinook salmon (Oncorhynchus tshawytscha) spawner population size through time leads to different relative densities over space. Twenty-six years of monitoring data on spawning Chinook salmon across the entire coast of Oregon, USA, were used to evaluate models that make contrasting statements about the interactions of a latent population abundance parameter with physical habitat characteristics. There is strong information-theoretic support for models that include terms that allow the spatial variation in density to change as population size changes through time. Analysis of the best model reveals nonlinear isodars, which suggests a 'despotic' or 'preemptive' distribution of individuals across habitats, indicating that dominant or early-arriving individuals exclude others from breeding sites. This finding has implications for genetic dynamics, population dynamics and conservation metrics of these highly valued fish. The novel application of modelling techniques used here to assess mechanisms of habitat selection from observational data can be used in the emerging field of eco-evolutionary dynamics. PMID:25283166

Falcy, Matthew R

2014-10-01

384

Demersal fish and habitat associations from visual surveys on the central California shelf  

NASA Astrophysics Data System (ADS)

In 2004, we surveyed demersal fishes and habitats on the continental shelf off central California (65-110 m depth) using the occupied submersible Delta. Our objectives were to estimate the relative abundance of habitats and to examine demersal fish species composition, diversity, density, and sizes relative to these habitats. A total of 112 transects were completed covering 32 km of seafloor. A higher density of fishes was estimated in boulder and cobble habitats than in mud and brachiopod beds. More than 80% of the fishes were small, measuring 20 cm or less in total length. Species with small maximum size (primarily pygmy rockfish, Sebastes wilsoni, and blackeye gobies, Rhinogobiops nicholsii) accounted for nearly half (49%) of the total number of 12,441 fishes. Most fishes were immature, with only 4 of 20 harvested species having more than 50% of the individuals larger than the size at first maturity. Our study area on the continental shelf may be an ontogenetic transition zone for immature fishes before they move to their adult habitat on the slope. Alternatively, historical fishing pressure may have contributed to the lack of large, mature fishes in the survey area. Understanding the importance of these habitats to fishes at various life stages will improve our ability to assess these deepwater fish stocks and effectively manage these living resources on an ecosystem basis.

Laidig, Thomas E.; Watters, Diana L.; Yoklavich, Mary M.

2009-08-01

385

Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2010  

SciTech Connect

This report describes the 2010 research conducted under the U.S. Army Corps of Engineers (USACE) project EST-P-09-1, titled Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, and known as the 'Salmon Benefits' study. The primary goal of the study is to establish scientific methods to quantify habitat restoration benefits to listed salmon and trout in the lower Columbia River and estuary (LCRE) in three required areas: habitat connectivity, early life history diversity, and survival (Figure ES.1). The general study approach was to first evaluate the state of the science regarding the ability to quantify benefits to listed salmon and trout from habitat restoration actions in the LCRE in the 2009 project year, and then, if feasible, in subsequent project years to develop quantitative indices of habitat connectivity, early life history diversity, and survival. Based on the 2009 literature review, the following definitions are used in this study. Habitat connectivity is defined as a landscape descriptor concerning the ability of organisms to move among habitat patches, including the spatial arrangement of habitats (structural connectivity) and how the perception and behavior of salmon affect the potential for movement among habitats (functional connectivity). Life history is defined as the combination of traits exhibited by an organism throughout its life cycle, and for the purposes of this investigation, a life history strategy refers to the body size and temporal patterns of estuarine usage exhibited by migrating juvenile salmon. Survival is defined as the probability of fish remaining alive over a defined amount of space and/or time. The objectives of the 4-year study are as follows: (1) develop and test a quantitative index of juvenile salmon habitat connectivity in the LCRE incorporating structural, functional, and hydrologic components; (2) develop and test a quantitative index of the early life history diversity of juvenile salmon in the LCRE; (3) assess and, if feasible, develop and test a quantitative index of the survival benefits of tidal wetland habitat restoration (hydrologic reconnection) in the LCRE; and (4) synthesize the results of investigations into the indices for habitat connectivity, early life history diversity, and survival benefits.

Diefenderfer, Heida L.; Johnson, Gary E.; Sather, Nichole K.; Skalski, J. R.; Dawley, Earl M.; Coleman, Andre M.; Ostrand, Kenneth G.; Hanson, Kyle C.; Woodruff, Dana L.; Donley, Erin E.; Ke, Yinghai; Buenau, Kate E.; Bryson, Amanda J.; Townsend, Richard L.

2011-10-01

386

Integration Process for the Habitat Demonstration Unit  

NASA Technical Reports Server (NTRS)

The Habitat Demonstration Unit (HDU) is an experimental exploration habitat technology and architecture test platform designed for analog demonstration activities. The HDU previously served as a test bed for testing technologies and sub-systems in a terrestrial surface environment. in 2010 in the Pressurized Excursion Module (PEM) configuration. Due to the amount of work involved to make the HDU project successful, the HDU project has required a team to integrate a variety of contributions from NASA centers and outside collaborators The size of the team and number of systems involved With the HDU makes Integration a complicated process. However, because the HDU shell manufacturing is complete, the team has a head start on FY--11 integration activities and can focus on integrating upgrades to existing systems as well as integrating new additions. To complete the development of the FY-11 HDU from conception to rollout for operations in July 2011, a cohesive integration strategy has been developed to integrate the various systems of HDU and the payloads. The highlighted HDU work for FY-11 will focus on performing upgrades to the PEM configuration, adding the X-Hab as a second level, adding a new porch providing the astronauts a larger work area outside the HDU for EVA preparations, and adding a Hygiene module. Together these upgrades result in a prototype configuration of the Deep Space Habitat (DSH), an element under evaluation by NASA's Human Exploration Framework Team (HEFT) Scheduled activates include early fit-checks and the utilization of a Habitat avionics test bed prior to installation into HDU. A coordinated effort to utilize modeling and simulation systems has aided in design and integration concept development. Modeling tools have been effective in hardware systems layout, cable routing, sub-system interface length estimation and human factors analysis. Decision processes on integration and use of all new subsystems will be defined early in the project to maximize the efficiency of both integration and field operations. In addition a series of tailored design reviews are utilized to quickly define the systems and their integration into the DSH configuration. These processes are necessary to ensure activities, such as partially reversing integration of the X-Hab second story of the HDU and deploying and stowing the new work porch for transportation to the JSC Rock Yard and to the Arizona Black Point Lava Flow Site are performed with minimal or no complications. In addition, incremental test operations leading up to an Integrated systems test allows for an orderly systems test program. For FY-11 activities, the HDU DSH will act as a laboratory utilizing a new X-Hab inflatable second floor with crew habitation features. In addition to the day to day operations involving maintenance of the HDU and exploring the surrounding terrain, testing and optimizing the use of the new X-Hab, work porch, Hygiene Module, and other sub-system enhancements will be the focus of the FY-11 test objectives. The HDU team requires a successful integration strategy using a variety of tools and approaches to prepare the DSH for these test objectives. In a challenging environment where the prototyping influences the system design, as well as Vice versa, results of the HDU DSH field tests will influence future designs of habitat systems.

Gill, Tracy; Merbitz, Jerad; Kennedy, Kriss; Tn, Terry; Toups, Larry; Howe, A. Scott; Smitherman, David

2011-01-01

387

HABITAT DATA MAPSPROG USER'S MANUAL -131 Why enter and  

E-print Network

HABITAT DATA MAPSPROG USER'S MANUAL - 131 Why enter and verify Habitat data? Assess habitat structure within your station boundary IX. HABITAT STRUCTURE ASSESSMENT DATA A. PREVIEW The Habitat Structure Assessment (HSA) data, as described in the Habitat Structure Assessment Protocol, provide

DeSante, David F.

388

Habitat Suitability Index Models: American Alligator  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a model for evaluating American alligator habitat quality. The model is applicable in marshes along the northern Gulf of Mexico. It is scaled to produce an index between 0 (unsuitable habitat) and 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 and techniques for measuring model variables are described.

Newsom, John D.; Joanen, Ted; Howard, Rebecca J.

1987-01-01

389

The effects of habitat fragmentation on the social kin structure and mating system of the agile antechinus, Antechinus agilis.  

PubMed

Habitat fragmentation is one of the major contributors to the loss of biodiversity worldwide. However, relatively little is known about its more immediate impacts on within-patch population processes such as social structure and mating systems, whose alteration may play an important role in extinction risk. We investigated the impacts of habitat fragmentation due to the establishment of an exotic softwood plantation on the social kin structure and breeding system of the Australian marsupial carnivore, Antechinus agilis. Restricted dispersal by males in fragmented habitat resulted in elevated relatedness among potential mates in populations in fragments, potentially increasing the risk of inbreeding. Antechinus agilis nests communally in tree hollows; these nests are important points for social contact between males and females in the mating season. In response to elevated relatedness among potential mates in fragmented habitat, A. agilis significantly avoided sharing nests with opposite-sex relatives in large fragment sites (but not in small ones, possibly due to limited nest locations and small population sizes). Because opposite-sex individuals shared nests randomly with respect to relatedness in unfragmented habitat, we interpreted the phenomenon in fragmented habitat as a precursor to inbreeding avoidance via mate choice. Despite evidence that female A. agilis at high inbreeding risk selected relatively unrelated mates, there was no overall increased avoidance of related mates by females in fragmented habitats compared to unfragmented habitats. Simulations indicated that only dispersal, and not nonrandom mating, contributed to inbreeding avoidance in either habitat context. However, habitat fragmentation did influence the mating system in that the degree of multiple paternity was reduced due to the reduction in population sizes and population connectivity. This, in turn, reduced the number of males available to females in the breeding season. This suggests that in addition to the obvious impacts of reduced recruitment, patch recolonization and increased genetic drift, the isolation of populations in habitat patches may cause changes in breeding behaviour that contribute to the negative impacts of habitat fragmentation. PMID:15836650

Banks, S C; Ward, S J; Lindenmayer, D B; Finlayson, G R; Lawson, S J; Taylor, A C

2005-05-01

390

Risky prey behavior evolves in risky habitats.  

PubMed

Longstanding theory in behavioral ecology predicts that prey should evolve decreased foraging rates under high predation threat. However, an alternative perspective suggests that growth into a size refuge from gape-limited predation and the future benefits of large size can outweigh the initial survival costs of intense foraging. Here, I evaluate the relative contributions of selection from a gape-limited predator (Ambystoma opacum) and spatial location to explanations of variation in foraging, growth, and survival in 10 populations of salamander larvae (Ambystoma maculatum). Salamander larvae from populations naturally exposed to intense A. opacum predation risk foraged more actively under common garden conditions. Higher foraging rates were associated with low survival in populations exposed to free-ranging A. opacum larvae. Results demonstrate that risky foraging activity can evolve in high predation-risk habitats when the dominant predators are gape-limited. This finding invites the further exploration of diverse patterns of prey foraging behavior that depends on natural variation in predator size-selectivity. In particular, prey should adopt riskier behaviors under predation threat than expected under existing risk allocation models if foraging effort directly reduces the duration of risk by growth into a size refuge. Moreover, evidence from this study suggests that foraging has evolved over microgeographic scales despite substantial modification by regional gene flow. This interaction between local selection and spatial location suggests a joint role for adaptation and maladaptation in shaping species interactions across natural landscapes, which is a finding with implications for dynamics at the population, community, and metacommunity levels. PMID:17724339

Urban, Mark C

2007-09-01

391

Risky prey behavior evolves in risky habitats  

PubMed Central

Longstanding theory in behavioral ecology predicts that prey should evolve decreased foraging rates under high predation threat. However, an alternative perspective suggests that growth into a size refuge from gape-limited predation and the future benefits of large size can outweigh the initial survival costs of intense foraging. Here, I evaluate the relative contributions of selection from a gape-limited predator (Ambystoma opacum) and spatial location to explanations of variation in foraging, growth, and survival in 10 populations of salamander larvae (Ambystoma maculatum). Salamander larvae from populations naturally exposed to intense A. opacum predation risk foraged more actively under common garden conditions. Higher foraging rates were associated with low survival in populations exposed to free-ranging A. opacum larvae. Results demonstrate that risky foraging activity can evolve in high predation-risk habitats when the dominant predators are gape-limited. This finding invites the further exploration of diverse patterns of prey foraging behavior that depends on natural variation in predator size-selectivity. In particular, prey should adopt riskier behaviors under predation threat than expected under existing risk allocation models if foraging effort directly reduces the duration of risk by growth into a size refuge. Moreover, evidence from this study suggests that foraging has evolved over microgeographic scales despite substantial modification by regional gene flow. This interaction between local selection and spatial location suggests a joint role for adaptation and maladaptation in shaping species interactions across natural landscapes, which is a finding with implications for dynamics at the population, community, and metacommunity levels. PMID:17724339

Urban, Mark C.

2007-01-01

392

Effects of habitat fragmentation and disturbance on howler monkeys: a review.  

PubMed

We examined the literature on the effects of habitat fragmentation and disturbance on howler monkeys (genus Alouatta) to (1) identify different threats that may affect howlers in fragmented landscapes; (2) review specific predictions developed in fragmentation theory and (3) identify the empirical evidence supporting these predictions. Although howlers are known for their ability to persist in both conserved and disturbed conditions, we found evidence that they are negatively affected by high levels of habitat loss, fragmentation and degradation. Patch size appears to be the main factor constraining populations in fragmented habitats, probably because patch size is positively related to food availability, and negatively related to anthropogenic pressures, physiological stress and parasite loads. Patch isolation is not a strong predictor of either patch occupancy or population size in howlers, a result that may be related to the ability of howlers to move among forest patches. Thus, we propose that it is probable that habitat loss has larger consistent negative effects on howler populations than habitat fragmentation per se. In general, food availability decreases with patch size, not only due to habitat loss, but also because the density of big trees, plant species richness and howlers' home range size are lower in smaller patches, where howlers' population densities are commonly higher. However, it is unclear which vegetation attributes have the biggest influence on howler populations. Similarly, our knowledge is still limited concerning the effects of postfragmentation threats (e.g. hunting and logging) on howlers living in forest patches, and how several endogenous threats (e.g. genetic diversity, physiological stress, and parasitism) affect the distribution, population structure and persistence of howlers. More long-term studies with comparable methods are necessary to quantify some of the patterns discussed in this review, and determine through meta-analyses whether there are significant inter-specific differences in species' responses to habitat loss and fragmentation. PMID:19852004

Arroyo-Rodríguez, Víctor; Dias, Pedro Américo D

2010-01-01

393

Cannibalism as the cause of an ontogenetic shift in habitat use by fry of the threespine stickleback  

Microsoft Academic Search

In Crystal Lake, British Columbia, small fry (=15 mm SL) of the threespine stickleback (Gasterosteus aculeatus) are concentrated in vegetation while larger fry are not. Because fry in all size classes feed primarily on zooplankton, even when in vegetation, we hypothesized that size-limited predation was responsible for the observed shift in habitat use with size. The major predators on fry

S. A. Foster; V. B. Garcia; M. Y. Town

1988-01-01

394

Dispersing brush mice prefer habitat like home  

PubMed Central

During natal dispersal, young animals leave their natal area and search for a new area to live. In species in which individuals inhabit different types of habitat, experience with a natal habitat may increase the probability that a disperser will select the same type of habitat post-dispersal (natal habitat preference induction or NHPI). Despite considerable interest in the ecological and the evolutionary implications of NHPI, we lack empirical evidence that it occurs in nature. Here we show that dispersing brush mice (Peromyscus boylii) are more likely to search and settle within their natal habitat type than expected based on habitat availability. These results document the occurrence of NHPI in nature and highlight the relevance of experience-generated habitat preferences for ecological and evolutionary processes. PMID:18077253

Mabry, Karen E; Stamps, Judy A

2007-01-01

395

Subsurface microbial habitats on Mars  

NASA Technical Reports Server (NTRS)

We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

Boston, P. J.; Mckay, C. P.

1991-01-01

396

Descent Assisted Split Habitat Lunar Lander Concept  

NASA Technical Reports Server (NTRS)

The Descent Assisted Split Habitat (DASH) lunar lander concept utilizes a disposable braking stage for descent and a minimally sized pressurized volume for crew transport to and from the lunar surface. The lander can also be configured to perform autonomous cargo missions. Although a braking-stage approach represents a significantly different operational concept compared with a traditional two-stage lander, the DASH lander offers many important benefits. These benefits include improved crew egress/ingress and large-cargo unloading; excellent surface visibility during landing; elimination of the need for deep-throttling descent engines; potentially reduced plume-surface interactions and lower vertical touchdown velocity; and reduced lander gross mass through efficient mass staging and volume segmentation. This paper documents the conceptual study on various aspects of the design, including development of sortie and outpost lander configurations and a mission concept of operations; the initial descent trajectory design; the initial spacecraft sizing estimates and subsystem design; and the identification of technology needs

Mazanek, Daniel D.; Goodliff, Kandyce; Cornelius, David M.

2008-01-01

397

Mapping Deep-sea Habitats  

NSDL National Science Digital Library

In this lesson students investigate bathymetric mapping of deep-sea habitats to see how deep-sea areas of the northwestern Hawaiian Islands can be mapped to facilitate their exploration with a manned submersible. Students will create a two-dimensional topographic map from bathymetric survey data, a three-dimensional model of landforms from a two-dimensional topographic map, and will interpret two- and three-dimensional topographic data.

Mel Goodwin

398

Carnivorous Plants and Their Habitats  

NSDL National Science Digital Library

This image gallery provides photos of carnivorous plants shown in their natural habitats. The photos are arranged by genus and by geographic region. Each image is accompanied by a brief caption including genus, species, and location. There is also a specialized gallery featuring carnivorous plants of Europe, a discussion on how to cultivate these plants in vitro, and a brief bibliography of publications on carnivorous plants by the site's creator, Dr. Joachim Nerz.

Dr. Joachim Nerz

2002-06-18

399

Climate Change Expands the Spatial Extent and Duration of Preferred Thermal Habitat for Lake Superior Fishes  

PubMed Central

Climate change is expected to alter species distributions and habitat suitability across the globe. Understanding these shifting distributions is critical for adaptive resource management. The role of temperature in fish habitat and energetics is well established and can be used to evaluate climate change effects on habitat distributions and food web interactions. Lake Superior water temperatures are rising rapidly in response to climate change and this is likely influencing species distributions and interactions. We use a three-dimensional hydrodynamic model that captures temperature changes in Lake Superior over the last 3 decades to investigate shifts in habitat size and duration of preferred temperatures for four different fishes. We evaluated habitat changes in two native lake trout (Salvelinus namaycush) ecotypes, siscowet and lean lake trout, Chinook salmon (Oncorhynchus tshawytscha), and walleye (Sander vitreus). Between 1979 and 2006, days with available preferred thermal habitat increased at a mean rate of 6, 7, and 5 days per decade for lean lake trout, Chinook salmon, and walleye, respectively. Siscowet lake trout lost 3 days per decade. Consequently, preferred habitat spatial extents increased at a rate of 579, 495 and 419 km2 per year for the lean lake trout, Chinook salmon, and walleye while siscowet lost 161 km2 per year during the modeled period. Habitat increases could lead to increased growth and production for three of the four fishes. Consequently, greater habitat overlap may intensify interguild competition and food web interactions. Loss of cold-water habitat for siscowet, having the coldest thermal preference, could forecast potential changes from continued warming. Additionally, continued warming may render more suitable conditions for some invasive species. PMID:23638023

Cline, Timothy J.; Bennington, Val; Kitchell, James F.

2013-01-01

400

Climate change expands the spatial extent and duration of preferred thermal habitat for lake Superior fishes.  

PubMed

Climate change is expected to alter species distributions and habitat suitability across the globe. Understanding these shifting distributions is critical for adaptive resource management. The role of temperature in fish habitat and energetics is well established and can be used to evaluate climate change effects on habitat distributions and food web interactions. Lake Superior water temperatures are rising rapidly in response to climate change and this is likely influencing species distributions and interactions. We use a three-dimensional hydrodynamic model that captures temperature changes in Lake Superior over the last 3 decades to investigate shifts in habitat size and duration of preferred temperatures for four different fishes. We evaluated habitat changes in two native lake trout (Salvelinus namaycush) ecotypes, siscowet and lean lake trout, Chinook salmon (Oncorhynchus tshawytscha), and walleye (Sander vitreus). Between 1979 and 2006, days with available preferred thermal habitat increased at a mean rate of 6, 7, and 5 days per decade for lean lake trout, Chinook salmon, and walleye, respectively. Siscowet lake trout lost 3 days per decade. Consequently, preferred habitat spatial extents increased at a rate of 579, 495 and 419 km(2) per year for the lean lake trout, Chinook salmon, and walleye while siscowet lost 161 km(2) per year during the modeled period. Habitat increases could lead to increased growth and production for three of the four fishes. Consequently, greater habitat overlap may intensify interguild competition and food web interactions. Loss of cold-water habitat for siscowet, having the coldest thermal preference, could forecast potential changes from continued warming. Additionally, continued warming may render more suitable conditions for some invasive species. PMID:23638023

Cline, Timothy J; Bennington, Val; Kitchell, James F

2013-01-01

401

Influence of habitat amount, arrangement, and use on population trend estimates of male Kirtland's warblers  

USGS Publications Warehouse

Kirtland's warblers (Dendroica kirtlandii) persist in a naturally patchy environment of young, regenerating jack pine forests (i.e., 5-23 years old) created after wildfires and human logging activities. We examined how changing landscape structure from 26 years of forest management and wildfire disturbances influenced population size and spatial dispersion of male Kirtland's warblers within their restricted breeding range in northern Lower Michigan, USA. The male Kirtland's warbler population was six times larger in 2004 (1,322) compared to 1979 (205); the change was nonlinear with 1987 and 1994 identified as significant points of change. In 1987, the population trend began increasing after a slowly declining trend prior to 1987, and the rate of increase appeared to slow after 1994. Total amount of suitable habitat and the relative area of wildfire-regenerated habitat were the most important factors explaining population trend. Suitable habitat increased 149% primarily due to increasing plantations from forest management. The relative amount and location of wildfire-regenerated habitat modified the distribution of males among various habitat types, and the spatial variation in their abundance across the primary breeding range. These findings indicate that the Kirtland's warbler male population shifted its use of habitat types temporally and spatially as the population increased and as the relative availability of habitats changed through time. We demonstrate that researchers and managers need to consider not only habitat quality, but the temporal and the spatial context of habitat availability and population levels when making habitat restoration decisions. ?? 2008 Springer Science+Business Media B.V.

Donner, D.M.; Probst, J.R.; Ribic, C.A.

2008-01-01

402

Effects of Frugivore Preferences and Habitat Heterogeneity on Seed Rain: A Multi-Scale Analysis  

PubMed Central

Seed rain mediated by frugivores is influenced by (1) the seed-deposition distances following fruit ingestion, (2) the disperser activity, as determined by its behaviour and habitat preferences, and (3) the structure of the habitat within the landscape. Here, we evaluated such components using the fleshy-fruited shrub Ephedra fragilis and the frugivorous Balearic lizard Podarcis lilfordi. We estimated seed-deposition patterns based on the displacements and habitat preferences of lizards, derived from visual surveys and telemetry data. The influence of variables potentially determining lizard habitat preference (i.e., height, slope, four measures of habitat abundance and four measures of habitat fragmentation) was evaluated at three spatial scales: ‘home-range’ (c. 2.5–10*103 m2; telemetry data), ‘within home-range’ (c. 100 m2; telemetry data) and ‘microhabitat’ (<100 m2; visual survey). Cumulative lizard displacement (from each telemetric location to the initial capture point) saturated before the peak of seed defecation (seed-retention time), indicating that lizard home-range size and habitat preferences were the main determinants of the spread and shape of seed shadows. Shrub cover was positively correlated with habitat preference at the three scales of analysis, whereas slope was negatively correlated at the home-range scale. Model scenarios indicated that spatially-aggregated seed rain emerged when we incorporated the joint effect of habitat preference at the two largest (home-range and within home-range) scales. We conclude that, in order to predict seed rain in animal dispersed plants, it is important to consider the multi-scale effects of habitat preference by frugivores. PMID:22438902

Rodríguez-Pérez, Javier; Larrinaga, Asier R.; Santamaría, Luis

2012-01-01

403

Sandy beach surf zones: An alternative nursery habitat for 0-age Chinook salmon  

NASA Astrophysics Data System (ADS)

The role of each habitat fish use is of great importance to the dynamics of populations. During their early marine residence, Chinook salmon (Oncorhynchus tshawytscha), an anadromous fish species, mostly inhabit estuaries but also use sandy beach surf zones and the coastal ocean. However, the role of surf zones in the early life history of Chinook salmon is unclear. We hypothesized that surf zones serve as an alternative nursery habitat, defined as a habitat that consistently provides a proportion of a population with foraging and growth rates similar to those experienced in the primary nursery. First, we confirmed that juvenile Chinook salmon cohorts are simultaneously using both habitats by combining field collections with otolith chemical and structural analysis to directly compare size and migration patterns of juveniles collected in two Oregon (USA) estuaries and surf zones during three years. We then compared juvenile catch, diet and growth in estuaries and surf zones. Juveniles were consistently caught in both habitats throughout summer. Catches were significantly higher in estuaries (average ± SD = 34.3 ± 19.7 ind. 100 m-2) than surf zones (1.0 ± 1.5 ind. 100 m-2) and were positively correlated (r = 0.92). Size at capture (103 ± 15 mm fork length, FL), size at marine entry (76 ± 13 mm FL), stomach fullness (2 ± 2% body weight) and growth rates (0.4 ± 0.0 mm day-1) were similar between habitats. Our results suggest that when large numbers of 0-age Chinook salmon inhabit estuaries, juveniles concurrently use surf zones, which serve as an alternative nursery habitat. Therefore, surf zones expand the available rearing habitat for Chinook salmon during early marine residence, a critical period in the life history.

Marin Jarrin, J. R.; Miller, J. A.

2013-12-01

404

Maladaptive Habitat Selection of a Migratory Passerine Bird in a Human-Modified Landscape  

PubMed Central

In human-altered environments, organisms may preferentially settle in poor-quality habitats where fitness returns are lower relative to available higher-quality habitats. Such ecological trapping is due to a mismatch between the cues used during habitat selection and the habitat quality. Maladaptive settlement decisions may occur when organisms are time-constrained and have to rapidly evaluate habitat quality based on incomplete knowledge of the resources and conditions that will be available later in the season. During a three-year study, we examined settlement decision-making in the long-distance migratory, open-habitat bird, the Red-backed shrike (Lanius collurio), as a response to recent land-use changes. In Northwest Europe, the shrikes typically breed in open areas under a management regime of extensive farming. In recent decades, Spruce forests have been increasingly managed with large-size cutblocks in even-aged plantations, thereby producing early-successional vegetation areas that are also colonised by the species. Farmland and open areas in forests create mosaics of two different types of habitats that are now occupied by the shrikes. We examined redundant measures of habitat preference (order of settlement after migration and distribution of dominant individuals) and several reproductive performance parameters in both habitat types to investigate whether habitat preference is in line with habitat quality. Territorial males exhibited a clear preference for the recently created open areas in forests with higher-quality males settling in this habitat type earlier. Reproductive performance was, however, higher in farmland, with higher nest success, offspring quantity, and quality compared to open areas in forests. The results showed strong among-year consistency and we can therefore exclude a transient situation. This study demonstrates a case of maladaptive habitat selection in a farmland bird expanding its breeding range to human-created open habitats in plantations. We discuss the reasons that could explain this decision-making and the possible consequences for the population dynamics and persistence. PMID:21984940

Hollander, Franck A.; Van Dyck, Hans; San Martin, Gilles; Titeux, Nicolas

2011-01-01

405

Serving Sizes  

NSDL National Science Digital Library

In this nutrition and estimation activity (page 12 of PDF), learners estimate serving sizes of different foods and compare their estimates to serving size information provided on nutrition food labels. A Quick Hand Measures guide helps learners visualize serving sizes of different foods using their hand (i.e. a closed fist = serving size of a piece of fruit). This activity also introduces learners to solid and liquid measures. This guide includes background information, setup and management tips, extensions, reliable resource links and handouts.

Nancy P. Moreno

2009-01-01

406

Engineering novel habitats on urban infrastructure to increase intertidal biodiversity.  

PubMed

Urbanization replaces natural shorelines with built infrastructure, seriously impacting species living on these "new" shores. Understanding the ecology of developed shorelines and reducing the consequences of urban development to fauna and flora cannot advance by simply documenting changes to diversity. It needs a robust experimental programme to develop ways in which biodiversity can be sustained in urbanized environments. There have, however, been few such experiments despite wholesale changes to shorelines in urbanized areas. Seawalls--the most extensive artificial infrastructure--are generally featureless, vertical habitats that support reduced levels of local biodiversity. Here, a mimic of an important habitat on natural rocky shores (rock-pools) was experimentally added to a seawall and its impact on diversity assessed. The mimics created shaded vertical substratum and pools that retained water during low tide. These novel habitats increased diversity of foliose algae and sessile and mobile animals, especially higher on the shore. Many species that are generally confined to lowshore levels, expanded their distribution over a greater tidal range. In fact, there were more species in the constructed pools than in natural pools of similar size on nearby shores. There was less effect on the abundances of mobile animals, which may be due to the limited time available for recruitment, or because these structures did not provide appropriate habitat. With increasing anthropogenic intrusion into natural areas and concomitant loss of species, it is essential to learn how to build urban infrastructure that can maintain or enhance biodiversity while meeting societal and engineering criteria. Success requires melding engineering skills and ecological understanding. This paper demonstrates one cost-effective way of addressing this important issue for urban infrastructure affecting nearshore habitats. PMID:19551409

Chapman, M G; Blockley, D J

2009-09-01

407

Comparing the nursery role of inner continental shelf and estuarine habitats for temperate marine fishes  

NASA Astrophysics Data System (ADS)

The marine-estuarine transition represents an important biogeographic boundary, yet juvenile marine finfish have been observed in both temperate inner continental shelf (ICS) and estuarine habitats during the summer nursery period. In a direct comparison of ICS and estuary nurseries, spatial and temporal patterns in species composition, biodiversity, size structure, and relative abundance of age-0 fishes were tested using contemporaneous data from multiyear (2004-2006) trawl surveys of the Maryland ICS near Assateague Island, MD, and lower Chesapeake Bay, VA (estuary). Survey data from both habitats showed similar seasonal progression of assemblage structure, biodiversity phenologies, and dominant species identities. Late summer densities for four of five numerically dominant species varied by habitat. Densities of bay anchovy Anchoa mitchilli, weakfish Cynoscion regalis, and Atlantic butterfish Peprilus triacanthus were higher in the ICS; whereas summer flounder Paralichthys dentatus density was higher in the estuary. Density of spot Leiostomus xanthurus did not differ between habitats. Apparent daily growth rates of these five species, as estimated by modal length progression, were not significantly different between the two habitats. Although individual species displayed varying affinities for ICS versus estuarine habitats, this study provides strong evidence that the ICS of the Middle Atlantic Bight is capable of functioning interchangeably with polyhaline estuarine regions as nursery habitat for a diverse group of marine finfish.

Woodland, Ryan J.; Secor, David H.; Fabrizio, Mary C.; Wilberg, Michael J.

2012-03-01

408

The relative influence of habitat amount and configuration on genetic structure across multiple spatial scales  

PubMed Central

Despite strong interest in understanding how habitat spatial structure shapes the genetics of populations, the relative importance of habitat amount and configuration for patterns of genetic differentiation remains largely unexplored in empirical systems. In this study, we evaluate the relative influence of, and interactions among, the amount of habitat and aspects of its spatial configuration on genetic differentiation in the pitcher plant midge, Metriocnemus knabi. Larvae of this species are found exclusively within the water-filled leaves of pitcher plants (Sarracenia purpurea) in a system that is naturally patchy at multiple spatial scales (i.e., leaf, plant, cluster, peatland). Using generalized linear mixed models and multimodel inference, we estimated effects of the amount of habitat, patch size, interpatch distance, and patch isolation, measured at different spatial scales, on genetic differentiation (FST) among larval samples from leaves within plants, plants within clusters, and clusters within peatlands. Among leaves and plants, genetic differentiation appears to be driven by female oviposition behaviors and is influenced by habitat isolation at a broad (peatland) scale. Among clusters, gene flow is spatially restricted and aspects of both the amount of habitat and configuration at the focal scale are important, as is their interaction. Our results suggest that both habitat amount and configuration can be important determinants of genetic structure and that their relative influence is scale dependent. PMID:25628865

Millette, Katie L; Keyghobadi, Nusha

2015-01-01

409

Response of the Agile Antechinus to Habitat Edge, Configuration and Condition in Fragmented Forest  

PubMed Central

Habitat fragmentation and degradation seriously threaten native animal communities. We studied the response of a small marsupial, the agile antechinus Antechinus agilis, to several environmental variables in anthropogenically fragmented Eucalyptus forest in south-east Australia. Agile antechinus were captured more in microhabitats dominated by woody debris than in other microhabitats. Relative abundances of both sexes were positively correlated with fragment core area. Male and female mass-size residuals were smaller in larger fragments. A health status indicator, haemoglobin-haematocrit residuals (HHR), did not vary as a function of any environmental variable in females, but male HHR indicated better health where sites' microhabitats were dominated by shrubs, woody debris and trees other than Eucalyptus. Females were trapped less often in edge than interior fragment habitat and their physiological stress level, indicated by the neutrophil/lymphocyte ratio in peripheral blood, was higher where fragments had a greater proportion of edge habitat. The latter trend was potentially due to lymphopoenia resulting from stress hormone-mediated leukocyte trafficking. Using multiple indicators of population condition and health status facilitates a comprehensive examination of the effects of anthropogenic disturbances, such as habitat fragmentation and degradation, on native vertebrates. Male agile antechinus' health responded negatively to habitat degradation, whilst females responded negatively to the proportion of edge habitat. The health and condition indicators used could be employed to identify conservation strategies that would make habitat fragments less stressful for this or similar native, small mammals. PMID:22076129

Johnstone, Christopher P.; Lill, Alan; Reina, Richard D.

2011-01-01

410

Response of the agile antechinus to habitat edge, configuration and condition in fragmented forest.  

PubMed

Habitat fragmentation and degradation seriously threaten native animal communities. We studied the response of a small marsupial, the agile antechinus Antechinus agilis, to several environmental variables in anthropogenically fragmented Eucalyptus forest in south-east Australia. Agile antechinus were captured more in microhabitats dominated by woody debris than in other microhabitats. Relative abundances of both sexes were positively correlated with fragment core area. Male and female mass-size residuals were smaller in larger fragments. A health status indicator, haemoglobin-haematocrit residuals (HHR), did not vary as a function of any environmental variable in females, but male HHR indicated better health where sites' microhabitats were dominated by shrubs, woody debris and trees other than Eucalyptus. Females were trapped less often in edge than interior fragment habitat and their physiological stress level, indicated by the neutrophil/lymphocyte ratio in peripheral blood, was higher where fragments had a greater proportion of edge habitat. The latter trend was potentially due to lymphopoenia resulting from stress hormone-mediated leukocyte trafficking. Using multiple indicators of population condition and health status facilitates a comprehensive examination of the effects of anthropogenic disturbances, such as habitat fragmentation and degradation, on native vertebrates. Male agile antechinus' health responded negatively to habitat degradation, whilst females responded negatively to the proportion of edge habitat. The health and condition indicators used could be employed to identify conservation strategies that would make habitat fragments less stressful for this or similar native, small mammals. PMID:22076129

Johnstone, Christopher P; Lill, Alan; Reina, Richard D

2011-01-01

411

Size Matters  

ERIC Educational Resources Information Center

This article describes the immense size of Unity Junior High School in Cicero, Illinois and the opinions of various people regarding its size. The school has more than 2,700 students, seventeen acres, eighty-eight faculty lounges, and ninety-six security cameras. Administrators hope the school--"Cicero's crown jewel," as the school district's Web…

Gehring, John

2004-01-01

412

Habitat Loss other than Fragmentation per se Decreased Nuclear and Chloroplast Genetic Diversity in a Monoecious Tree  

PubMed Central

Generally, effect of fragmentation per se on biodiversity has not been separated from the effect of habitat loss. In this paper, using nDNA and cpDNA SSRs, we studied genetic diversity of Castanopsis sclerophylla (Lindl. & Paxton) Schotty populations and decoupled the effects of habitat loss and fragmentation per se. We selected seven nuclear and six cpDNA microsatellite loci and genotyped 460 individuals from mainland and island populations, which were located in the impoundment created in 1959. Number of alleles per locus of populations in larger habitats was significantly higher than that in smaller habitats. There was a significant relationship between the number of alleles per locus and habitat size. Based on this relationship, the predicted genetic diversity of an imaginary population of size equaling the total area of the islands was lower than that of the global population on the islands. Re-sampling demonstrated that low genetic diversity of populations in small habitats was caused by unevenness in sample size. Fisher's ? index was similar among habitat types. These results indicate that the decreased nuclear and chloroplast genetic diversity of populations in smaller habitats was mainly caused by habitat loss. For nuclear and chloroplast microsatellite loci, values of FST were 0.066 and 0.893, respectively, and the calculated pollen/seed dispersal ratio was 162.2. When separated into pre-and post-fragmentation cohorts, pollen/seed ratios were 121.2 and 189.5, respectively. Our results suggest that habitat loss explains the early decrease in genetic diversity, while fragmentation per se may play a major role in inbreeding and differentiation among fragmented populations and later loss of genetic diversity. PMID:22723951

Shen, Dong-Wei; Chen, Xiao-Yong

2012-01-01

413

Structural Definition and Mass Estimation of Lunar Surface Habitats for the Lunar Architecture Team Phase 2 (LAT-2) Study  

NASA Technical Reports Server (NTRS)

The Lunar Architecture Team Phase 2 study defined and assessed architecture options for a Lunar Outpost at the Moon's South Pole. The Habitation Focus Element Team was responsible for developing concepts for all of the Habitats and pressurized logistics modules particular to each of the architectures, and defined the shapes, volumes and internal layouts considering human factors, surface operations and safety requirements, as well as Lander mass and volume constraints. The Structures Subsystem Team developed structural concepts, sizing estimates and mass estimates for the primary Habitat structure. In these studies, the primary structure was decomposed into a more detailed list of components to be sized to gain greater insight into concept mass contributors. Structural mass estimates were developed that captured the effect of major design parameters such as internal pressure load. Analytical and empirical equations were developed for each structural component identified. Over 20 different hard-shell, hybrid expandable and inflatable soft-shell Habitat and pressurized logistics module concepts were sized and compared to assess structural performance and efficiency during the study. Habitats were developed in three categories; Mini Habs that are removed from the Lander and placed on the Lunar surface, Monolithic habitats that remain on the Lander, and Habitats that are part of the Mobile Lander system. Each category of Habitat resulted in structural concepts with advantages and disadvantages. The same modular shell components could be used for the Mini Hab concept, maximizing commonality and minimizing development costs. Larger Habitats had higher volumetric mass efficiency and floor area than smaller Habitats (whose mass was dominated by fixed items such as domes and frames). Hybrid and pure expandable Habitat structures were very mass-efficient, but the structures technology is less mature, and the ability to efficiently package and deploy internal subsystems remains an open issue.

Dorsey, John T.; Wu, K, Chauncey; Smith, Russell W.

2008-01-01

414

MoSI Habitat Assessment Form Location:___ ___ ___ ___ Station:___ ___ ___ ___ Date:____/____/________ (mm/dd/year) Observers  

E-print Network

MoSI Habitat Assessment Form Location:___ ___ ___ ___ Station:___ ___ ___ ___ Date:____/____/________ (mm/dd/year) Observers: Total number of habitat types present:_____ Notes: Habitat Type Letter ____ (from Station Habitat Map) Percent of study area covered by habitat type (determine from Station Habitat

DeSante, David F.

415

Clockwork: Hands On For Habitat  

NSDL National Science Digital Library

Clockwork is "a self directed, theatre-based education package about biological diversity." Produced by Vox Bandicoot in collaboration with the Biodiversity Group (Environment Australia), the Clockwork site offers four sections: Midnight, an introduction to and philosophy of biological diversity, Mainspring, a hands-on lesson in critical concepts about threatened species and habitats, Big Hand and Little Hand, curriculum support material for classroom teachers, and Cog and Spindle, general science and ecological background about Australia. Though depth of content varies, environmental educators will be interested in this fresh and creative approach.

Vox Bandicoot.

416

Habitat heterogeneity, species diversity and null models  

Microsoft Academic Search

The habitat heterogeneity hypothesis states that an increase in habitat heterogeneity leads to an increase in species diversity. We tested this hypothesis for a community of small mammals in the semiarid, sand-shinnery-oak ecosystem of the southwestern United States. We used indices of differentiation diversity to quantify differences between two habitat types (blowouts in a sand-shinnery-oak matrix) in terms of species

Michael J. Cramer; Michael R. Willig

2005-01-01

417

Size Wheel  

NSDL National Science Digital Library

In this fun sticker activity, learners will create a size wheel with images of objects of different size, from macroscopic scale (like an ant) to nanoscale (like DNA). Learners will be able to understand the difference in sizes and also learn about how small objects look when examined with special imaging technology such as a Scanning Electron Microscope. The activity includes images of: ant, dust mite, hair, virus, chromosome, spider web, penny, red blood cell, DNA, optic fiber, pollen grain, microchip, flagellum, plant cell, and silk threads.

2012-06-26

418

Measuring and modeling the spatial pattern of understory bamboo across landscapes: Implications for giant panda habitat  

NASA Astrophysics Data System (ADS)

We examined an approach to classifying understory bamboo, the staple food of the giant panda (Ailuropoda melanoleuca), from remote sensing imagery in the Wolong Nature Reserve, China. We also used these data to estimate the landscape-scale distribution of giant panda habitat, and model the human effects on forest cover and the spatio-temporal dynamics of bamboo and the resulting implications for giant panda habitat. The spatial distribution of understory bamboo was mapped using an artificial neural network and leaf-on remote sensing data. Training on a limited set of ground truth data and using widely available Landsat TM data as input, a non-linear artificial neural network achieved a classification accuracy of 80% despite the presence of co-occurring mid-story and understory vegetation. Using information on the spatial distribution of bamboo in Wolong, we compared the results of giant panda habitat analyses with and without bamboo information. Total amount of habitat decreased by 29--56% and overall habitat patch size decreased by 16--48% after bamboo information was incorporated into the analyses. The decreases in the quantity of panda habitat and increases in habitat fragmentation resulted in decreases of 41--60% in carrying capacity. Using a spatio-temporal model of bamboo dynamics and human activities, we found that local fuelwood collection and household creation will likely reduce secondary habitat relied upon by pandas. Human impacts would likely contribute up to an additional 16% loss of habitat. Furthermore, these impacts primarily occur in the habitat relied upon by giant pandas during past bamboo die-offs. Decreased total area of habitat and increased fragmentation from human activities will likely make giant pandas increasingly sensitive to natural disturbances such as cyclical bamboo die-offs. Our studies suggest that it is necessary to further examine approaches to monitor understory vegetation and incorporate understory information into wildlife habitat research and management. The success here to map bamboo has important implications for giant panda conservation and provides a good foundation for developing methods to map the spatial distributions of understory plant species. Knowledge of the spatial distribution of bamboo is necessary to accurately measure the quantity and landscape characteristics of giant panda habitat. (Abstract shortened by UMI.)

Linderman, Marc Alan

419

Habitat Demonstration Unit - Deep Space Habitat Configuration - Duration: 2:22.  

NASA Video Gallery

This animated video shows the process of transporting, assembling and testing the Habitat Demonstration Unit - Deep Space Habitat (HDU DSH) configuration, which will be deployed during the 2011 Des...

420

75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Policy task force goals and in identifying focus areas for the estuary habitat restoration strategy, such as: climate adaptation restoration, socio-economic benefits of estuary habitat restoration, and geographic restoration...

2010-06-21

421

Elevation Derivatives for Mojave Desert Tortoise Habitat  

USGS Publications Warehouse

This report describes the methods used to derive various elevation-derivative grids that were inputted to the Mojave Desert Tortoise Habitat model (L. Gass and others, unpub. data). These grids, which capture information on surface roughness and topographic characteristics, are a subset of the environmental datasets evaluated for the tortoise habitat model. This habitat model is of major importance to the U.S. Fish and Wildlife Service, which is charged with management of this threatened population, including relocating displaced tortoises to areas identified as suitable habitat.

Wallace, Cynthia S.A.; Gass, Leila

2008-01-01

422

Habitat patterns in a small mammal community  

SciTech Connect

Microhabitat relationships between four sympatric small mammal species (Peromyscus leucopus, Ochrotomys nuttalli, Blarina brevicauda, and Tamias striatus) were examined to determine if their discriminant analysis of small mammal habitat represented a unique habitat utilization pattern for a specific small mammal community. The authors concluded that habitat is only one of many dimensions to be considered when studying the interactions of sympatric species. Reproductive strategy, activity patterns, and other factors make up the n-dimensional hyperspace of an animal's niche. Thus differences in habitat usage alone cannot be used to determine niche overlap and competition between species. (JMT)

Kitchings, J.T.; Levy, D.J.

1981-11-01

423

Multistate modeling of habitat dynamics: Factors affecting Florida scrub transition probabilities  

USGS Publications Warehouse

Many ecosystems are influenced by disturbances that create specific successional states and habitat structures that species need to persist. Estimating transition probabilities between habitat states and modeling the factors that influence such transitions have many applications for investigating and managing disturbance-prone ecosystems. We identify the correspondence between multistate capture-recapture models and Markov models of habitat dynamics. We exploit this correspondence by fitting and comparing competing models of different ecological covariates affecting habitat transition probabilities in Florida scrub and flatwoods, a habitat important to many unique plants and animals. We subdivided a large scrub and flatwoods ecosystem along central Florida's Atlantic coast into 10-ha grid cells, which approximated average territory size of the threatened Florida Scrub-Jay (Aphelocoma coerulescens), a management indicator species. We used 1.0-m resolution aerial imagery for 1994, 1999, and 2004 to classify grid cells into four habitat quality states that were directly related to Florida Scrub-Jay source-sink dynamics and management decision making. Results showed that static site features related to fire propagation (vegetation type, edges) and temporally varying disturbances (fires, mechanical cutting) best explained transition probabilities. Results indicated that much of the scrub and flatwoods ecosystem was resistant to moving from a degraded state to a desired state without mechanical cutting, an expensive restoration tool. We used habitat models parameterized with the estimated transition probabilities to investigate the consequences of alternative management scenarios on future habitat dynamics. We recommend this multistate modeling approach as being broadly applicable for studying ecosystem, land cover, or habitat dynamics. The approach provides maximum-likelihood estimates of transition parameters, including precision measures, and can be used to assess evidence among competing ecological models that describe system dynamics. ?? 2010 by the Ecological Society of America.

Breininger, D.R.; Nichols, J.D.; Duncan, B.W.; Stolen, E.D.; Carter, G.M.; Hunt, D.K.; Drese, J.H.

2010-01-01

424

Animal habitats for space experiments.  

PubMed

There has been little opportunity for flight experiments using small animals, due to delay of construction of the International Space Station. Therefore, proposals using small animals have been unfortunately excepted from International Space Life Sciences Experiment application opportunity since 2001. Moreover, NASA has changed their development plan of animal habitats for space experiments according to changes of the U.S. space policy and the outlook is not so bright. However, international researchers have been strongly requesting the opportunity for space experiments using small animals. It will be also important for Japanese researchers to make a request for the opportunity. At the same time, researchers have to make an advance in ground based studies toward space experiments and to respond future application opportunities immediately. In this symposium, we explain the AEM (Animal Enclosure Module), the RAHF (Research Animal Holding Facility), and the AAH (Advanced Animal Habitat). It will be helpful for investigators to have wide knowledge of what space experiment is technically possible. In addition, the sample share program will be introduced into our communities. The program will provide many researchers with the organs and tissues from space-flown animals. We will explain the technical aspect of sample share program. PMID:15858343

Fukui, Keiji; Shimazu, Toru

2004-11-01

425

Sea Ice, an Antarctic Habitat  

NSDL National Science Digital Library

A 'click-and-learn' sub site hosted by the Alfred Wegener Institute Foundation for Polar and Marine Research (AWI), this is a succinct, educational tour of sea-ice and its associated ecological communities. Short synopses introduce the dynamics of sea-ice formation, the microstructure of sea-ice (including crystal structure, brine channels, and ice algae), the effects of ice melt on resident organisms, the logistics of sea-ice research, and _land fast-ice_ and platelet ice habitats. Introductions also exist for the following organisms: krill; whales (i.e., Orcas, southern bottlenosesd dolphins, minke whales); sea birds (i.e., skuas and snow petrals), penguins (i.e., emperor, adelie, and chinstraps), and seals (i.e., weddell, crabeater, leopard, and ross.) Enlargeable thumbnail images accompany the habitat and inhabitant descriptions. Further investigations (at an accelerated level) are prompted with the inclusion of bibliographic references and scientific research presentations (in PDF format) on fast-ice and platelet ice, as well as links to the main site for the AWI.

426

MOURNING DOVE NESTING HABITAT AND NEST SUCCESS IN CENTRAL MISSOURI  

Microsoft Academic Search

Previous Mourning Dove (Zenaida macroura) nesting studies conducted in areas containing a mixture of edge and continuous habitats have focused on edge habitats. Con- sequently, little is known about the potential contribution of continuous habitats to dove production. In this study we evaluated the relative importance of these two extensive habitat types by monitoring the habitat use and nest success

RONALD D. DROBNEY; JOHN H. SCHULZ; STEVEN L. SHERIFF; WESLEY J. FUEMMELER

427

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...

428

Habitat suitability index models: inland silverside. [Menidia beryllina  

Microsoft Academic Search

A review and synthesis of existing information were used to develop a model for evaluating inland silverside habitat quality. The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimal habitat) along the Atlantic coast of the United States from Massachusetts to New Jersey. Habitat suitability index models are designed for use with

1986-01-01

429

BENTHIC MACROFAUNA-HABITAT RELATIONSHIPS IN TWO PACIFIC NORTHWEST ESTUARIES  

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 benthic macrofauna-habitat relationships for 8 intertidal habitats i...

430

Environmental adaptation in stomatal size independent of the effects of genome size  

PubMed Central

Cell sizes are linked across multiple tissues, including stomata, and this variation is closely correlated with genome size. These associations raise the question of whether generic changes in cell size cause suboptimal changes in stomata, requiring subsequent evolution under selection for stomatal size. We tested the relationships among guard cell length, genome size and vegetation type using phylogenetically independent analyses on 67 species of the ecologically and structurally diverse family, Proteaceae. We also compared how genome and stomatal sizes varied at ancient (among genera) and more recent (within genus) levels. The observed 60-fold range in genome size in Proteaceae largely reflected the mean chromosome size. Compared with variation among genera, genome size varied much less within genera (< 6% of total variance) than stomatal size, implying evolution in stomatal size subsequent to changes in genome size. Open vegetation and closed forest had significantly different relationships between stomatal and genome sizes. Ancient changes in genome size clearly influenced stomatal size in Proteaceae, but adaptation to habitat strongly modified the genome–stomatal size relationship. Direct adaptation to the environment in stomatal size argues that new proxies for past concentrations of atmospheric CO2 that incorporate stomatal size are superior to older models based solely on stomatal frequency. PMID:25266914

Jordan, Gregory J; Carpenter, Raymond J; Koutoulis, Anthony; Price, Aina; Brodribb, Timothy J

2015-01-01

431

Evolution of extreme body size disparity in monitor lizards (Varanus).  

PubMed

Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards. PMID:21884063

Collar, David C; Schulte, James A; Losos, Jonathan B

2011-09-01

432

Interpretation of landscape pattern and habitat change for local indicator species using satellite imagery and geographic information system data in New Brunswick, Canada  

Microsoft Academic Search

We measured the extent and rate of habitat change and interpreted landscape metrics for fragmentation in the Fundy Model Forest, New Brunswick, from 1993 to 1999 using geographical information system baseline data up- dated with landscape changes detected on Landsat satellite imagery. We report on three categories of landscape metrics (habitat cover, patch size, and nearest neighbour), which we interpret

Matthew G. Betts; Steven E. Franklin; Ron G. Taylor

2003-01-01

433

SKYLAB II - Making a Deep Space Habitat from a Space Launch System Propellant Tank  

NASA Technical Reports Server (NTRS)

Called a "House in Space," Skylab was an innovative program that used a converted Saturn V launch vehicle propellant tank as a space station habitat. It was launched in 1973 fully equipped with provisions for three separate missions of three astronauts each. The size and lift capability of the Saturn V enabled a large diameter habitat, solar telescope, multiple docking adaptor, and airlock to be placed on-orbit with a single launch. Today, the envisioned Space Launch System (SLS) offers similar size and lift capabilities that are ideally suited for a Skylab type mission. An envisioned Skylab II mission would employ the same propellant tank concept; however serve a different mission. In this case, the SLS upper stage hydrogen tank is used as a Deep Space Habitat (DSH) for NASA s planned missions to asteroids, Earth-Moon Lagrangian point and Mars.

Griffin, Brand N.; Smitherman, David; Kennedy, Kriss J.; Toups, Larry; Gill, Tracy; Howe, A. Scott

2012-01-01

434

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

PubMed Central

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

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

2013-01-01

435

Assessing alternative anthropogenic habitats for conserving waterbirds: salinas as buffer areas against the impact of natural habitat loss for shorebirds  

Microsoft Academic Search

Because many natural waterbird habitats are threatened by human disturbance and sea level rise, it is vitally important to identify alternative wetlands that may supplement declining natural habitats. Coastal salinas are anthropogenic habitats used for obtaining salt by evaporation of sea water. These habitats support important numbers of waterbirds around the world, but their importance as feeding habitats is poorly

JOSE A. MASERO ´ ´

2003-01-01

436

Ecological and allometric determinants of home-range size for mountain lions (Puma concolor)  

E-print Network

Ecological and allometric determinants of home-range size for mountain lions (Puma concolor influence home-range size for moun- tain lions and whether they can be used to predict home- range size that influence home-range size of 57 mountain lions across three distinct habitats in California. Identifying

Beier, Paul

437

The maintenance of shore-level size gradients in an intertidal snail ( Littorina sitkana )  

Microsoft Academic Search

The size of many intertidal animals varies with tidal height. These size gradients could be produced by growth or survival varying with tidal height, or by animals moving to a preferred tidal level. The body size of the snail, Littorina sitkana, increases steadily with tidal height in rocky high intertidal habitats of British Columbia. To determine how size gradients were

Susan M. D. McCormack

1982-01-01

438

Influences of fluctuating flows on spawning habitat and recruitment success  

NASA Astrophysics Data System (ADS)

Over the 50 years of daily peak power generation, no ramping restrictions, and loss of gravel due to operations of Philpott Dam, on Smith River, has created a wider, rectangular-shaped channel, with steeper banks. The pattern caused by channel degradation, tributary headcutting, bank erosion, and downstream aggradation has limited the length of productive habitat to between 3 and 10 river kilometers from the dam. Here the channel appears to contain key habitats where we found the highest redd densities, abundance, and spawner biomass for brown trout (Salmo trutta). Recruitment of brown trout to the fishable size classes is constrained by the daily hydropower peaking operations. The number of young brown trout produced each year was strongly related to the average magnitude of the peak flow and the duration of generation flows. Magnitude of peak flows also depressed abundance of native fishes. Although, brown trout actively removed fine sediment via redd construction and spawning, thereby increasing gravel permeability, the fine sediments from tributaries and bank erosion rapidly intruded into the spawning gravel in downstream reaches of the river. We recommend mitigating the effects of fluctuating releases from Philpott Dam through a combination of flow management and habitat improvement.

Orth, D. J.; Krause, C. W.; Novinger, D. C.

2005-05-01

439

The Selection and Design of Multiple-Species Habitat Preserves.  

PubMed

Multiple-species habitat conservation plans (MSHCPs) are designed to eliminate project-by-project review and minimize species-by-species conflicts; but these one-time, short-term processes invariably compress the divergent expectations of interest groups into an exercise driven by economic, amenity, and aesthetic values rather than scientific values. Participants may define an MSHCP as an exchange of habitat preserves for federal permits to take populations of endangered animals and plants, but the outcome is typically driven by overarching arguments over land development and suburban sprawl. Existing land uses also constrain the size, shape, and linkages among wildlife habitats, leading to a divergence of MSHCPs from the scientific preserve selection and design literature. Problems created by constraints to preserve configuration (e.g., land costs, fragmentation, pre-existing amounts of edge, lack of connectivity) must be resolved by long-term, post facto management. To date, estimates of preserve persistence have not been used in MSHCPs. Rather than focus on map-based exercises of preserve elements, it may be more productive to set goals for the persistence of species (states) and ecosystems (processes) within the preserves-accepting that preserve configurations and arrays will be defined by the landscape and politics of suburban areas and that long-term management will provide the primary means of maintaining biodiversity along the wildland/urban interface. PMID:10801989

SCOTT; SULLIVAN

2000-07-01

440

Wireless Sensor Networks for Habitat Monitoring  

Microsoft Academic Search

We provide an in-depth study of applying wireless sensor networks to real-world habitat monitoring. A set of system design requirements are developed that cover the hardware design of the nodes, the design of the sensor network, and the capabilities for remote data access and management. A system architecture is proposed to address these requirements for habitat monitoring in general, and

Alan M. Mainwaring; Joseph Polastre; Robert Szewczyk

2002-01-01

441

HABITAT MODELING APPROACHES FOR RESTORATION SITE SELECTION  

EPA Science Inventory

Numerous modeling approaches have been used to develop predictive models of species-environment and species-habitat relationships. These models have been used in conservation biology and