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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

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

3

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

4

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.

5

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

SciTech Connect

Research on the effects of creating group-selection openings of various sizes on breeding birds habitat use in a bottomland hardwood forest of the Upper Coastal Plain of South Carolina. Creation of 0.5-ha group selection openings in southern bottomland forests should provide breeding habitat for some field-edge species in gaps and habitat for forest-interior species and canopy-dwelling forest-edge species between gaps provided that enough mature forest is made available.

Moorman, C.E.; D.C. Guynn, Jr.

2001-12-01

6

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...

7

The effect of breeding-habitat patch size on bird population density  

Microsoft Academic Search

An individual-based simulation model was used to study the effect of the relative location of food and nest sites in the landscape on the relationship between the breeding habitat patch size and bird population density. The model predicted that when both food and nest sites are located exclusively in the breeding habitat patches, larger patches tend to harbor higher population

Cristián F. Estades

2001-01-01

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

How Does Habitat Patch Size Affect Animal Movement? An Experiment with Darkling Beetles  

Microsoft Academic Search

We used an experimental model system consisting of darkling beetles (Co- leoptera: Tenebrionidae, Eleodes obsoleta Say) in a microlandscape to assess the effects of habitat patch size on the movement patterns of animals. The ratio of habitat area to nonhabitat in a 25-m2 \\

NANCY E. McINTYREl; John A. Wiens

1999-01-01

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

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

12

Habitat richness affects home range size in the red fox Vulpes vulpes  

Microsoft Academic Search

The spatial behaviour of the red fox Vulpes vulpes shows a great flexibility (Voigt and Macdonald, 1984). Home range size varies from 10 to over 5000 ha (Macdonald, 1987; Voigt, 1987). In carnivores, variations in home range size, weighed for body mass (Gittleman and Harvey, 1982), are largely related to differences in habitat productivity, but the intraspecific local variation in

M. Lucherini; S. Lovari

1996-01-01

13

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

14

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

15

Estimating the population size of an endangered shorebird, the Madagascar plover, using a habitat suitability model  

E-print Network

Estimating the population size of an endangered shorebird, the Madagascar plover, using a habitat, Antananarivo, Madagascar 3 School of Biosciences, University of Exeter in Cornwall, Penryn, Cornwall, UK 2007; accepted 19 December 2007 doi:10.1111/j.1469-1795.2008.00157.x Abstract The Madagascar plover

16

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

17

RESTORING COASTAL HABITAT USING MARSH TERRACING: THE EFFECT OF CELL SIZE ON NEKTON USE  

E-print Network

RESTORING COASTAL HABITAT USING MARSH TERRACING: THE EFFECT OF CELL SIZE ON NEKTON USE Lawrence P-mail: lawrence.rozas@noaa.gov 2 Galveston Laboratory 4700 Avenue U Galveston, Texas, USA 77551 Abstract: Marsh terracing is used to restore coastal wetlands by converting shallow nonvegetated bottom to intertidal marsh

18

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...

19

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

Microsoft Academic Search

Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly\\u000a size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size\\u000a structure of common carp (Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural

Janusz Kloskowski; Marek Nieoczym; Marcin Polak; Piotr Pitucha

2010-01-01

20

Population size, habitat fragmentation, and the nature of adaptive variation in a stream fish.  

PubMed

Whether and how habitat fragmentation and population size jointly affect adaptive genetic variation and adaptive population differentiation are largely unexplored. Owing to pronounced genetic drift, small, fragmented populations are thought to exhibit reduced adaptive genetic variation relative to large populations. Yet fragmentation is known to increase variability within and among habitats as population size decreases. Such variability might instead favour the maintenance of adaptive polymorphisms and/or generate more variability in adaptive differentiation at smaller population size. We investigated these alternative hypotheses by analysing coding-gene, single-nucleotide polymorphisms associated with different biological functions in fragmented brook trout populations of variable sizes. Putative adaptive differentiation was greater between small and large populations or among small populations than among large populations. These trends were stronger for genetic population size measures than demographic ones and were present despite pronounced drift in small populations. Our results suggest that fragmentation affects natural selection and that the changes elicited in the adaptive genetic composition and differentiation of fragmented populations vary with population size. By generating more variable evolutionary responses, the alteration of selective pressures during habitat fragmentation may affect future population persistence independently of, and perhaps long before, the effects of demographic and genetic stochasticity are manifest. PMID:25056619

Fraser, Dylan J; Debes, Paul V; Bernatchez, Louis; Hutchings, Jeffrey A

2014-09-01

21

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

PubMed

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. PMID:20532472

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

2010-07-01

22

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

23

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

24

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

25

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

26

Relationships of Habitat Patch Size to Predator Community and Survival of Duck Nests  

NSDL National Science Digital Library

The Northern Prairie Wildlife Research Center (NPWRC) has posted several new (or newly online) resources on wetlands and birds. This resource by Marsha A. Sovada and others was recently published in Journal of Wildlife Management, 2000, [64(3):820-831] and examines the relationship between habitat patch size and duck nest survival as a function of predation rates. It may also be downloaded as a .zip file.

Beiser, Julia A.; Greenwood, Raymond J.; Newton, Wesley E.; Rave, David P.; Sovada, Marsha A.; Woodward, Robert O.

2000-01-01

27

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

28

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...

29

Estimates of minimum patch size depend on the method of estimation and the condition of the habitat.  

PubMed

Minimum patch size for a viable population can be estimated in several ways. The density-area method estimates minimum patch size as the smallest area in which no new individuals are encountered as one extends the arbitrary boundaries of a study area outward. The density-area method eliminates the assumption of no variation in density with size of habitat area that accompanies other methods, but it is untested in situations in which habitat loss has confined populations to small areas. We used a variant of the density area method to study the minimum patch size for the gopher tortoise (Gopherus polyphemus) in Florida, USA, where this keystone species is being confined to ever smaller habitat fragments. The variant was based on the premise that individuals within populations are likely to occur at unusually high densities when confined to small areas, and it estimated minimum patch size as the smallest area beyond which density plateaus. The data for our study came from detailed surveys of 38 populations of the tortoise. For all 38 populations, the areas occupied were determined empirically, and for 19 of them, duplicate surveys were undertaken about a decade apart. We found that a consistent inverse density area relationship was present over smaller areas. The minimum patch size estimated from the density-area relationship was at least 100 ha, which is substantially larger than previous estimates. The relative abundance of juveniles was inversely related to population density for sites with relatively poor habitat quality, indicating that the estimated minimum patch size could represent an extinction threshold. We concluded that a negative density area relationship may be an inevitable consequence of excessive habitat loss. We also concluded that any detrimental effects of an inverse density area relationship may be exacerbated by the deterioration in habitat quality that often accompanies habitat loss. Finally, we concluded that the value of any estimate of minimum patch size as a conservation tool is compromised by excessive habitat loss. PMID:17601133

McCoy, Earl D; Mushinsky, Henry R

2007-06-01

30

Relationship between body size and habitat complexity preference in age-0 and -1 year winter flounder Pseudopleuronectes americanus.  

PubMed

The interaction between body size, habitat complexity and interstice width on habitat preference of age-0 and -1 year Pseudopleuronectes americanus was examined using continuous remote video observation. The habitat choices of juvenile P. americanus were recorded over a 6 h period in tanks with four treatments: bare sand, sand with low complexity cobble, sand with intermediate complexity cobble and sand with high complexity cobble. Both age-0 and -1 year fish preferred cobble to bare sand. Within cobble treatments, age-0 year fish preferred intermediate complexity cobble, with a 1.59 ratio of interstitial space to body width. The largest age-1 year fish (123-130 mm standard length, L(S) ) preferred low complexity cobble. While a significant preference was not detected, medium age-1 year fish (83-88 mm L(S) ) tended to select low complexity cobble, whereas small age-1 year fish (73-82 mm L(S) ) tended to select low and intermediate cobble, with an interstitial space to body width ratio of 1.05. For medium and large age-1 year fish, there was an increased selection of low complexity cobble, corresponding to larger interstitial space to body size ratios. This study indicates that juvenile P. americanus prefer complex habitat to unstructured habitat and that this preference is mediated by a relationship between fish body size and the size of structure interstices. These results contribute to the growing body of knowledge of complex habitat selection and drivers of habitat choice in flatfishes. PMID:22747815

Pappal, A L; Rountree, R A; MacDonald, D G

2012-07-01

31

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

32

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

33

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 (...

34

Movements, Home-Range Size and Habitat Selection of Mallards during Autumn Migration  

PubMed Central

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

35

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

36

Size Structure of Marine Soft-Bottom Macrobenthic Communities across Natural Habitat Gradients: Implications for Productivity and Ecosystem Function  

PubMed Central

Size distributions of biotic assemblages are important modifiers of productivity and function in marine sediments. We investigated the distribution of proportional organic biomass among logarithmic size classes (2?6J to 216J) in the soft-bottom macrofaunal communities of the Strait of Georgia, Salish Sea on the west coast of Canada. The study examines how size structure is influenced by 3 fundamental habitat descriptors: depth, sediment percent fines, and organic flux (modified by quality). These habitat variables are uncorrelated in this hydrographically diverse area, thus we examine their effects in combination and separately. Cluster analyses and cumulative biomass size spectra reveal clear and significant responses to each separate habitat variable. When combined, habitat factors result in three distinct assemblages: (1) communities with a high proportion of biomass in small organisms, typical of shallow areas (<10 m) with coarse sediments (<10% fines) and low accumulation of organic material (<3.0 gC/m2/yr/?15N); (2) communities with high proportion of biomass in the largest organisms found in the Strait, typical of deep, fine sediments with high modified organic flux (>3 g C/m2/yr/?15N) from the Fraser River; and (3) communities with biomass dominated by moderately large organisms, but lacking the smallest and largest size classes, typical of deep, fine sediments experiencing low modified organic flux (<3.0 gC/m2/yr/?15N). The remaining assemblages had intermediate habitat types and size structures. Sediment percent fines and flux appear to elicit threshold responses in size structure, whereas depth has the most linear influence on community size structure. The ecological implications of size structure in the Strait of Georgia relative to environmental conditions, secondary production and sediment bioturbation are discussed. PMID:22911694

Macdonald, Tara A.; Burd, Brenda J.; van Roodselaar, Albert

2012-01-01

37

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

38

Size Structure of Marine Soft-Bottom Macrobenthic Communities across Natural Habitat Gradients: Implications for Productivity and Ecosystem Function  

Microsoft Academic Search

Size distributions of biotic assemblages are important modifiers of productivity and function in marine sediments. We investigated the distribution of proportional organic biomass among logarithmic size classes (2?6J to 216J) in the soft-bottom macrofaunal communities of the Strait of Georgia, Salish Sea on the west coast of Canada. The study examines how size structure is influenced by 3 fundamental habitat

Tara A. Macdonald; Brenda J. Burd; Albert van Roodselaar

2012-01-01

39

Assessing stability of body weight in the brushtail possum (Trichosurus vulpecula).  

PubMed

When conducting controlled laboratory studies with non-traditional laboratory animals it is important that methods for determining body weight stability are reliable. This helps ensure the health and welfare of animals when they are maintained during periods of free feeding or food restriction. This study compared different methods for determining body weight stability in six common brushtail possums (Trichosurus vulpecula) maintained on a free-feeding diet under laboratory conditions. A criterion of five consecutive weighings with less than ±2.5% change across days and no more than two consecutive days of weight loss or weight gain was judged to be the most suitable criteria for determining stability. It is important to study non-traditional animals, especially endangered or pest species, under controlled laboratory conditions and to have robust methods for establishing body weight stability. PMID:24958547

Cameron, Kristie E; Bizo, Lewis A; Starkey, Nicola J

2015-01-01

40

The hypothalamic-pituitary-ovarian axis and manipulations of the oestrous cycle in the brushtail possum.  

PubMed

The main purpose of this review is to provide a comprehensive update on what is known about the regulatory mechanisms of the hypothalamic-pituitary-ovarian axis in the brushtail possum, and to report on the outcomes of attempts made to manipulate by hormonal means, these processes in the possum. Over the last 15 years, several unique features of possum reproductive physiology have been discovered. These include an extended follicular phase despite elevated concentrations of FSH during the luteal phase, and early expression of LH receptors on granulosa cells of small antral follicles, suggesting a different mechanism for the selection of a dominant follicle. The use of routine synchronisation protocols that are effective in eutherians has failed to be effective in possums, and so the ability to reliably synchronise oestrus in this species remains a challenge. PMID:21074534

Crawford, Janet L; McLeod, Bernie J; Eckery, Douglas C

2011-02-01

41

FISH COMMUNITY STRUCTURE, SUBSTRATE PARTICLE SIZE, AND PHYSICAL HABITAT: AN ANALYSIS OF REFERENCE STREAMS IN THE WESTERN ALLEGHENY PLATEAU ECOREGION OF SOUTHEAST OHIO.  

E-print Network

?? Correlations between fish community structure, substrate particle size distributions, and physical habitat quality were investigated in wadeable and headwater reference streams within the Western… (more)

Hughes, Ian Matthew

2006-01-01

42

Group-size-mediated habitat selection and group fusion-fission dynamics of bison under predation risk.  

PubMed

For gregarious animals the cost-benefit trade-offs that drive habitat selection may vary dynamically with group size, which plays an important role in foraging and predator avoidance strategies. We examined how habitat selection by bison (Bison bison) varied as a function of group size and interpreted these patterns by testing whether habitat selection was more strongly driven by the competing demands of forage intake vs. predator avoidance behavior. We developed an analytical framework that integrated group size into resource selection functions (RSFs). These group-size-dependent RSFs were based on a matched case-control design and were estimated using conditional logistic regression (mixed and population-averaged models). Fitting RSF models to bison revealed that bison groups responded to multiple aspects of landscape heterogeneity and that selection varied seasonally and as a function of group size. For example, roads were selected in summer, but not in winter. Bison groups avoided areas of high snow water equivalent in winter. They selected areas composed of a large proportion of meadow area within a 700-m radius, and within those areas, bison selected meadows. Importantly, the strength of selection for meadows varied as a function of group size, with stronger selection being observed in larger groups. Hence the bison-habitat relationship depended in part on the dynamics of group formation and division. Group formation was most likely in meadows. In contrast, risk of group fission increased when bison moved into the forest and was higher during the time of day when movements are generally longer and more variable among individuals. We also found that stronger selection for meadows by large rather than small bison groups was caused by longer residence time in individual meadows by larger groups and that departure from meadows appears unlikely to result from a depression in food intake rate. These group-size-dependent patterns were consistent with the hypothesis that avoidance of predation risk is the strongest driver of habitat selection. PMID:19769126

Fortin, Daniel; Fortin, Marie-Eve; Beyer, Hawthorne L; Duchesne, Thierry; Courant, Sabrina; Dancose, Karine

2009-09-01

43

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

44

Millimeter-sized marine plastics: a new pelagic habitat for microorganisms and invertebrates.  

PubMed

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

45

Architecture of the basal region of the subcommissural organ in the brush-tailed possum ( Trichosurus vulpecula )  

Microsoft Academic Search

The architecture of the basal region of the subcommissural organ (SCO) and the subjacent neuropil was studied in the brush-tailed possum, Trichosurus vulpecula (Marsupialia). Several structural features suggest that the basal mode of SCO-secretion may be as prominent as the well-established apical secretion. Some of the features that speak in favour of basal secretion are: (1) the existence of deep

R. S. Tulsi

1983-01-01

46

Does landscape composition determine home range size of Blanding's Turtles, Emyoidea blandingii, in disturbed habitats in Ontario, Canada?  

E-print Network

Does landscape composition determine home range size of Blanding's Turtles, Emyoidea blandingii (Ecology, Evolution, Behaviour option) Supervisor: Gabriel Blouin-Demers BIO4009 April 2014 #12;2 ABSTRACT of Blanding's turtle (Emydoidea blandingii) habitat in Ontario has some degree of anthropogenic disturbance

Blouin-Demers, Gabriel

47

Sequence and analysis of zona pellucida 2 cDNA (ZP2) from a marsupial, the brushtail possum, Trichosurus vulpecula.  

PubMed

All mammalian eggs are surrounded by the zona pellucida, an extracellular coat involved in vital functions during fertilization and early development. The zona pellucida glycoproteins are promising antigenic targets for development of contraceptive vaccines to control pest populations of marsupials in Australia and New Zealand. Our current understanding of the function of the zona pellucida glycoproteins is based almost entirely on the mouse and may not be representative of gamete interactions in all eutherian or marsupial mammals. This study reports the isolation and characterization of the ZP2 gene from the brushtail possum (Trichosurus vulpecula). The brushtail possum ZP2 mRNA is 2,182 nucleotides long with an open reading frame coding for a polypeptide chain of 712 amino acids with a molecular mass of 79,542 d. The deduced amino acid sequence of possum ZP2 is 48 to 55% identical to that of eutherian mammals. It shares several structural characteristics including N-linked glycosylation sites, location and number of cysteine residues, and hydropathy profile. The brushtail possum ZP2 gene is expressed exclusively in the ovary. Further studies are planned to elucidate the specific site of ZP2 expression within the ovary and its function during fertilization in marsupials. PMID:9771653

Mate, K E; McCartney, C A

1998-11-01

48

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

49

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

50

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

51

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

PubMed

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

2014-10-01

52

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.

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

2014-01-01

53

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

54

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

55

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 ...

56

Lentic macroinvertebrate assemblage structure along gradients in spatial heterogeneity, habitat size and water chemistry  

Microsoft Academic Search

Littoral zones of small water bodies are spatially heterogeneous habitats, harbouring diverse biotic communities. Despite this apparent heterogeneity, many studies have stressed the importance of water chemistry in determining the structure of littoral macroinvertebrate assemblages. The purpose of this study was to consider the relative importance of several spatial and water chemistry variables in explaining the patterns in the structure

Jani Heino

2000-01-01

57

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

58

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

59

Seed size is heterogeneously distributed among destination habitats in animal dispersed plants  

Microsoft Academic Search

Seed size is a central trait in plants, conditioning the probabilities of seed dispersal, predation, germination and seedling survival even within a single species. In wind-dispersed species, seed size is not homogeneously distributed in the seed shadow, and it is clear that this trait influences dispersal distances. However, in animal-dispersed species, it is poorly known how and why the process

José Ramón Obeso; Isabel Martínez; Daniel García

2011-01-01

60

Habitat primary production and the evolution of body size within the hartebeest clade  

Microsoft Academic Search

Local adaptation is a key process in the evolution of biological diversity but relatively few studies have identified the selective forces that drive trait divergence at low taxonomic levels, particularly amongst mammals. Variation in body size across taxa is fundamental as shown by allometric relationships with numerous physiological, morphological and life-history traits. Differences in adult size across cohorts within populations

ISABELLA CAPELLINI; LEONARD MORRIS GOSLING

2007-01-01

61

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

62

A scanning electron microscope study of the pineal recess of the adult brush-tailed possum (Trichosurus vulpecula).  

PubMed Central

The ventricular surface features of the pineal recess of 35 adult brush-tailed possums (Trichosurus vulpecula) were studied, mainly with the scanning microscope. The complex and interesting details observed have not been reported before. The pineal recess shows three distinct zones, and it is suggested that these be called: central, paracentral, and peripheral. The surface cells of the central zone show neither cilia nor microvilli, the paracentral zone shows microvilli (in a polygonal and homogeneous array), supraependymal cells and CSF-contacting nerve processes, while the peripheral zone is heavily ciliated. These features are consistent with the hypothesis that, in certain physiological states, the CSF from the pineal recess carrying pineal secretion is momentarily 'swept' forward in the direction of the median eminence to influence hypothalamic functions directly. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 PMID:541240

Tulsi, R S

1979-01-01

63

Diversification Rates Increase With Population Size and Resource Concentration in an Unstructured Habitat  

PubMed Central

Understanding the mechanisms controlling the generation and maintenance of biodiversity provides some of the planet's greatest and most pressing challenges. Variation in resource concentration, which varies widely at multiple scales, may cause biodiversity to increase, decrease, or exhibit a unimodal response and underlying mechanisms remain obscure. We established experimental cultures of long-term stationary phase (LTSP) Escherichia coli to test whether per capita heterozygosity varies with resource concentration, and, if so, whether population sizes associated with different resource concentrations contributed to these patterns. Our results provide the clearest example to date of increasing per capita heterozygosity with increasing resource concentration. Further, our experimental manipulations of population size, independent of resource concentration, provide the first unequivocal evidence that population size is one of the underlying factors controlling per capita heterozygosity along such resource gradients. Specifically, we show that cultures with higher maximum population sizes, associated with higher resource concentrations, have higher per capita heterozygosity. These experiments provide the first experimental evidence for an underappreciated factor controlling biodiversity along resource gradients—population size. This direct evidence of population size influencing diversification rates has implications for regional and global scale patterns of biodiversity. PMID:18073429

Stevens, M. H. H.; Sanchez, M.; Lee, J.; Finkel, S. E.

2007-01-01

64

Diversification rates increase with population size and resource concentration in an unstructured habitat.  

PubMed

Understanding the mechanisms controlling the generation and maintenance of biodiversity provides some of the planet's greatest and most pressing challenges. Variation in resource concentration, which varies widely at multiple scales, may cause biodiversity to increase, decrease, or exhibit a unimodal response and underlying mechanisms remain obscure. We established experimental cultures of long-term stationary phase (LTSP) Escherichia coli to test whether per capita heterozygosity varies with resource concentration, and, if so, whether population sizes associated with different resource concentrations contributed to these patterns. Our results provide the clearest example to date of increasing per capita heterozygosity with increasing resource concentration. Further, our experimental manipulations of population size, independent of resource concentration, provide the first unequivocal evidence that population size is one of the underlying factors controlling per capita heterozygosity along such resource gradients. Specifically, we show that cultures with higher maximum population sizes, associated with higher resource concentrations, have higher per capita heterozygosity. These experiments provide the first experimental evidence for an underappreciated factor controlling biodiversity along resource gradients--population size. This direct evidence of population size influencing diversification rates has implications for regional and global scale patterns of biodiversity. PMID:18073429

Stevens, M H H; Sanchez, M; Lee, J; Finkel, S E

2007-12-01

65

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

66

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

67

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

68

Diurnal Habitat Selection and Home-range Size of Female Black Bears in the Ouachita Mountains of Oklahoma  

Microsoft Academic Search

bears averaged 14.5 and 21.0 km 2 as estimated by minimum convex polygon and adap- tive kernel methods, respectively. Based on compositional analysis, pine-hardwood and oak-hardwood poletimber stands were the highest-ranked habitat types at the study-area scale annually and during summer, whereas sawtimber of shortleaf pine (Pinus echinata), regeneration areas, and oak-hardwood sawtimber were the highest-ranked habitats at the home-range

Sara Bales Lyda; Eric C. Hellgren; David M. Leslie

2007-01-01

69

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

70

Habitat assessment ability of bumble-bees implies frequency-dependent selection on floral rewards and display size  

PubMed Central

Foraging pollinators could visit hundreds of flowers in succession on mass-flowering plants, yet they often visit only a small number—potentially saving the plant from much self-pollination among its own flowers (geitonogamy). This study tests the hypothesis that bumble-bee (Bombus impatiens) residence on a particular plant depends on an assessment of that plant's reward value relative to the overall quality experienced in the habitat. In a controlled environment, naive bees were given experience in a particular habitat (all plants having equal nectar quality or number of rewarding flowers), and we tested whether they learn about and adaptively exploit a new habitat type. Bees' residence on a plant (number of flowers probed per visit) was eventually invariant to a doubling of absolute nectar quality and increased only slightly with a doubling of absolute flower number in the habitat. These results help to explain why pollinators are quick to leave highly rewarding plants and suggest that the fitness of rewarding plant traits will often be frequency dependent. One implication is that geitonogamy may be a less significant constraint on the evolution of rewarding traits than generally supposed. PMID:17711839

Biernaskie, Jay M; Gegear, Robert J

2007-01-01

71

The contribution of habitat loss to changes in body size, allometry, and bilateral asymmetry in two Eleutherodactylus frogs from Puerto Rico.  

PubMed

Amphibian populations have been declining worldwide and the exact mechanisms underlying these changes are not well understood. We examined environmentally induced phenotypic changes that may reflect ongoing stresses on individuals and therefore their ability to persist in increasingly changing landscapes. Specifically, we evaluated the contribution of habitat loss on the size, allometry, and levels of fluctuating asymmetry of Eleutherodactylus antillensis and E. coqui, 2 common species that are endemic to Puerto Rico. We x-rayed frogs collected at 9 sites that differed in the amount of forest cover and measured their snout-vent, radio-ulna, femur, and tibio-fibula lengths. E. antillensis and E. coqui were smaller in the highly disturbed (< or =20% forest cover) than in the intermediately (20-70% forest cover) and little-disturbed (> or =70% forest cover) landscapes. In E. antillensis but not in E. coqui, the slope and intercept of the curves relating snout-vent length with the length of the 3 bones differed with degree of forest cover, suggesting an effect of habitat loss on body shape. In E. antillensis and E. coqui, differences between right and left sides corresponded to true fluctuating asymmetry; however, only the radio-ulna length of E. coqui showed a trend toward an increase in fluctuating asymmetry with habitat loss. Because body size scales with a variety of physiological, life history, and ecological traits, conservation programs aimed at monitoring morphological changes in amphibians may help in understanding the mechanisms that contribute to their persistence in changing environments. PMID:18477027

Delgado-Acevedo, Johanna; Restrepo, Carla

2008-06-01

72

Characterization of the hemoglobins of the neonatal brushtailed possum Trichosurus vulpecula (Kerr): evidence for a highly cooperative, aggregated isoform of hemoglobin.  

PubMed

The red blood cells of the neonatal brushtailed possum exhibit unusually strong cooperativity at high levels of oxygen saturation (n=5.4) which appear to arise from a concentration dependent aggregation of one of the neonatal hemoglobin isoforms. Red blood cells from neonatal pouched young exhibit a Bohr factor of -0.36. Stripped hemolysate is sensitive to added 2,3-bisphosphoglycerate (BPG) (apparent binding constant K=35 micromol L(-1)) and ATP (K=180 micromol L(-1)), but is largely insensitive towards chloride ions. Five isoforms of non-adult hemoglobin were identified using isoelectric focusing. Mass spectrometry indicated that two early isoforms contain alpha chains identical to the adult alpha chain. The remaining three isoforms are composed of identical alpha type and beta type gene products, but differ in their isoelectric points due to differential post-translational modification. PMID:18420437

Henty, Kristen; Wells, Rufus M G; Brittain, Thomas

2008-05-01

73

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...

74

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

75

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

PubMed Central

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 QST was similar – and larger than FST – 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

2013-01-01

76

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

77

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

78

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.

79

Habitat Alteration  

E-print Network

Habitat alteration is a change in land use or land cover that has an impact on local ecosystems. Plants and animals live in specific places that have the conditions of climate and food resources needed for survival. Habitats

unknown authors

80

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

81

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

82

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

83

Hydraulic habitat use with respect to body size of aquatic insect larvae: Case of six species from a French Mediterranean type stream  

Microsoft Academic Search

Macroinvertebrates play a key role in lotic ecosystems, as fish prey and processors of organic material. Therefore, their hydraulic preferences have to be integrated in instream habitat models for ecological stream management. This study characterized physical habitat use in terms of shear velocity for the larvae of three Ephemeropteran (Ephoron virgo, Oligoneuriella rhenana, and Serratella ignita), two Trichopteran (Cheumatopsyche lepida

Pierre Sagnes; Sylvie Mérigoux; Nicolas Péru

2008-01-01

84

Habitat: importance, destruction, & Habitat: importance, destruction, &  

E-print Network

Habitat: importance, destruction, & evaluation #12;Habitat: importance, destruction, & evaluation Organisms Habitat People Taxonomy Ecology Population dynamics Life history Stocking Introductions Population Biodiversity Genetics Restoration #12;What is habitat for fish? · Habitat for fish includes all of the physical

Limburg, Karin E.

85

Characteristics of insect populations on habitat fragments: A mini review  

Microsoft Academic Search

Modern human-dominated landscapes are typically characterized by intensive land-use and high levels of habitat destruction, often resulting in sharply contrasted habitat mosaics. Fragmentation of remaining habitat is a major threat to biodiversity. In the present paper, we focus on the different features of habitat fragmentation. First we discuss the importance of pure habitat loss, fragment size, fragment isolation and quality,

Teja Tscharntke; Ingolf Steffan-Dewenter; Andreas Kruess; Carsten Thies

2002-01-01

86

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

87

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

88

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.

89

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.

90

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

91

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

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

92

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

93

Considerations of a habitat design  

NASA Technical Reports Server (NTRS)

Habitats are the cost effective way to house people on the Moon for more than a couple of days. NASA, universities, and private industry have designed habitats to house astronauts for their lunar tour of duty. Designs range from 'campsites' to permanent 'cities' for human development of the Moon. Considering the high cost per round of equipment delivered to the Moon, each pound is questioned and minimized. Beyond the changing, mission-dependent requirements, such as duration, crew size, reusability, mission objectives, many general requirements are semi-constant for the lunar habitat design. Launch vehicle payload envelope, environment, operations, degree of commonality/optimization, radiation protection and support systems (thermal, environmental control, data handling, communications, power structures) affect the habitat design. Habitat design requirements with an emphasis on the semi-constant elements are explored in this paper.

Elrod, Molly

1995-01-01

94

Habitat quality predicts the distribution of a lizard in fragmented woodlands better than habitat fragmentation  

Microsoft Academic Search

Organisms often face a higher risk of local extinction in fragmented than in continuous habitat. However, whether populations are affected by reduced size and connectivity of the habitat or by changes in habitat quality in fragmented landscapes remains poorly investigated. We studied the regional distribution and microhabitat selection of the lacertid lizard Psammodromus algirus in a fragmented landscape where the

T. Santos; J. A. D ´ õaz; J. P ´ erez-Tris; R. Carbonell; J. L. Teller ´ õa

95

Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat  

NASA Technical Reports Server (NTRS)

NASA's Constellation Architecture Team defined an outpost scenario optimized for intensive mobility that uses small, highly mobile pressurized rovers supported by portable habitat modules that can be carried between locations of interest on the lunar surface. A compact vertical cylinder characterizes the habitat concept, where the large diameter maximizes usable flat floor area optimized for a gravity environment and allows for efficient internal layout. The module was sized to fit into payload fairings for the Constellation Ares V launch vehicle, and optimized for surface transport carried by the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) mobility system. Launch and other loads are carried through the barrel to a top and bottom truss that interfaces with a structural support unit (SSU). The SSU contains self-leveling feet and docking interfaces for Tri-ATHLETE grasping and heavy lift. A pressurized module needed to be created that was appropriate for the lunar environment, could be easily relocated to new locations, and could be docked together in multiples for expanding pressurized volume in a lunar outpost. It was determined that horizontally oriented pressure vessels did not optimize floor area, which takes advantage of the gravity vector for full use. Hybrid hard-inflatable habitats added an unproven degree of complexity that may eventually be worked out. Other versions of vertically oriented pressure vessels were either too big, bulky, or did not optimize floor area. The purpose of the HDU vertical habitat module is to provide pressurized units that can be docked together in a modular way for lunar outpost pressurized volume expansion, and allow for other vehicles, rovers, and modules to be attached to the outpost to allow for IVA (intra-vehicular activity) transfer between them. The module is a vertically oriented cylinder with a large radius to allow for maximal floor area and use of volume. The modular, 5- m-diameter HDU vertical habitat module consists of a 2-m-high barrel with 0.6-mhigh end domes forming the 56-cubicmeter pressure vessel, and a 19-squaremeter floor area. The module has up to four docking ports located orthogonally from each other around the perimeter, and up to one docking port each on the top or bottom end domes. In addition, the module has mounting trusses top and bottom for equipment, and to allow docking with the ATHLETE mobility system. Novel or unique features of the HDU vertical habitat module include the nodelike function with multiple pressure hatches for docking with other versions of itself and other modules and vehicles; the capacity to be carried by an ATHLETE mobility system; and the ability to attach inflatable 'attic' domes to the top for additional pressurized volume.

Howe, Alan; Kennedy, Kriss J.; Gill, Tracy R.; Tri, Terry O.; Toups, Larry; Howard, Robert I.; Spexarth, Gary R.; Cavanaugh, Stephen; Langford, William M.; Dorsey, John T.

2014-01-01

96

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

97

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.

Aquariums, Association O.

2009-01-01

98

WILDLIFE HABITAT  

EPA Science Inventory

Habitat change statistics were used to estimate the effects of alternative future scenarios for agriculture on non-fish vertebrate diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future scenarios w...

99

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

100

Morphological discrimination, habitat preferences, and size relationships of Peromyscus pectoralis and Peromyscus boylii from areas of sympatry in Northern Mexico and Western Texas  

E-print Network

and because smaller food 1tems are more abundant. Essentially the same situation has been observed by Berry (l975) in musk turtles (genus Sternotherus) in northern Florida, He found that as S. minor (the larger species) converged toward S. odoratus in size...

Modi, William Stephen

1978-01-01

101

Predator-mediated habitat use: some consequences for species interactions  

Microsoft Academic Search

Synopsis Behavioral responses to predators can have a major impact on a fishes' diet and habitat choice. Studies with the bluegill sunfish, Lepomis macrochirus, demonstrate that bluegills undergo pronounced shifts in diet and habitat use as they grow in response to changes in their vulnerability to predators. Other species of fish exhibit similar habitat shifts with body size, presumably also

Gary Mittelbach

1986-01-01

102

Great Lakes wetlands as amphibian habitats: A review  

Microsoft Academic Search

Amphibians are highly adapted for life in wetland habitats. They form a major component of wetland faunas, and being both prey and predator, they are important in ecosystem functioning. Wetlands provide aquatic habitats that amphibians require for breeding, development, foraging, hibernation and refuge, and they form an interface with essential adjacent upland habitat. The size and type of wetlands as

S. J. Hecnar

2004-01-01

103

Effect of habitat area and isolation on fragmented animal populations  

Microsoft Academic Search

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

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

2008-01-01

104

Habitat patches & landscape in protecting species I. Habitat v. landscape  

E-print Network

1 Habitat patches & landscape in protecting species I. Habitat v. landscape II. The landscape on non-reserve lands Approaches to solving conservation problems I. Habitat v. landscapes in conservation A. Habitat ­ Habitat Selection ­ a species' use of a habitat type at frequencies that differ from

Dever, Jennifer A.

105

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...

106

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.

107

Estuary Habitat Restoration INTRODUCTION  

E-print Network

1 Estuary Habitat Restoration STRATEGY 2012 INTRODUCTION The Estuary Restoration Act of 2000 (ERA agencies to maximize benefits derived from estuary habitat restoration projects and address the pressures facing our nation's estuaries. The ERA established an inter-agency Estuary Habitat Restoration Council

US Army Corps of Engineers

108

POTENTAIL HABITAT MOUNTAIN PLOVERS  

E-print Network

POTENTAIL HABITAT FOR MOUNTAIN PLOVERS ON COLORADO SPRINGS UTILITIES PROPERTY A Report to Colorado). To identify potential habitat on current and future Colorado Springs Utilities property, the Utility funded a habitat survey conducted by the Colorado Natural Heritage Program at Colorado State University. METHODS

109

Contact patterns as a risk factor for bovine tuberculosis infection in a free-living adult brushtail possum Trichosurus vulpecula population.  

PubMed

The aim of this study was to identify risk factors for bovine tuberculosis (TB) in a free-roaming, capture-mark-recapture monitored possum Trichosurus vulpecula population in a 22-ha study site at Castlepoint, New Zealand from 1 April 1989 to 31 March 1994. A matched case-control design was used to evaluate the influence of sex, habitat and contact opportunities on TB risk. Cases comprised possums identified as TB-positive throughout the study period. Controls were selected from the group of possums that were captured and showed no clinical signs of TB throughout the study period. Measures derived from a social network analysis of possum capture locations such as degree, clustering coefficient (CC) and betweenness were used to represent potential contact opportunities among possums. Network analysis measures recorded for individual possums in the 12-month period before a diagnosis of TB were evaluated in a conditional logistic regression model. We found no evidence of an association between case status and the total number of possums with which there was potential contact (degree) (P=0.5). The odds of cases being exposed to unit increases in the number of TB-positive contacts was 2.50 (95% CI 1.24-5.05; P<0.01) times that of controls. This effect was conditional on the total number of potential contacts made, with a negative interaction with increasing degree. These findings indicate that potential contact with TB-positive possums increases the odds of disease whereas potential contact with large numbers of possums does not. This suggests that multiple contacts with TB-positive possum(s) are necessary for transmission of TB and this is more likely to occur in networks that are smaller. We challenge the hypothesis that contact with large numbers of individuals increases the probability of becoming TB infected and argue that individual contact behaviour is a determinant of the creation of TB foci within free-living possum populations. PMID:21550126

Porphyre, T; McKenzie, J; Stevenson, M A

2011-07-01

110

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

111

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

112

Habitat Specialization in Tropical Continental Shelf Demersal Fish Assemblages  

PubMed Central

The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n?=?304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1–10 m depth), down the fore reef slope to the reef base (10–30 m depth) then across the adjacent continental shelf (30–110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected habitats through which fish can migrate. PMID:22761852

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

2012-01-01

113

Habitat-based polymorphism is common in stream fishes.  

PubMed

Morphological differences (size and shape) across habitats are common in lake fish where differences relate to two dominant contrasting habitats: the pelagic and littoral habitat. Repeated occurrence of littoral and pelagic morphs across multiple populations of several lake fish species has been considered as important evidence that polymorphism is adaptive in these systems. It has been suggested that these habitat-based polymorphic differences are due to the temporal stability of the differences between littoral and pelagic habitats. Although streams are spatially heterogeneous, they are also more temporally dynamic than lakes and it is still an open question whether streams provide the environmental conditions that promote habitat-based polymorphism. We tested whether fish from riffle, run and pool habitats, respectively, differed consistently in their morphology. Our test compared patterns of morphological variation (size and shape) in 10 fish species from the three stream habitat types in 36 separate streams distributed across three watersheds. For most species, body size and shape (after controlling for body size) differed across riffle, run and pool habitats. Unlike many lake species, the nature of these differences was not consistent across species, possibly because these species use these habitat types in different ways. Our results suggest that habitat-based polymorphism is an important feature also in stream fishes despite the fact that streams are temporally variable in contrast to lake systems. Future research is required to assess whether the patterns of habitat-based polymorphism encountered in streams have a genetic basis or they are simply the result of within generation phenotypic plasticity. PMID:25041645

Senay, Caroline; Boisclair, Daniel; Peres-Neto, Pedro R

2014-07-17

114

Habitat patches & landscape in protecting species I. Habitat v. landscape  

E-print Network

1 Habitat patches & landscape in protecting species I. Habitat v. landscape II. The landscape on non-reserve lands Approaches to solving conservation problems I. Habitat v. landscapes in conservation A. Habitat ­ the physical and biological surroundings of an organism Habitat Selection ­ a species

Dever, Jennifer A.

115

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.

116

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

117

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

118

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

119

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

120

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

121

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

122

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

123

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

124

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

125

PROCEDURE FOR DETERMINATION OF SEDIMENT PARTICLE SIZE (GRAIN SIZE)  

EPA Science Inventory

Sediment quality and sediment remediation projects have become a high priority for USEPA. Sediment particle size determinations are used in environmental assessments for habitat characterization, chemical normalization, and partitioning potential of chemicals. The accepted met...

126

Linking habitat heterogeneity to space use by large herbivores at multiple scales: From habitat mosaics to forest canopy openings  

E-print Network

-abundance Resource selection function White-tailed deer a b s t r a c t Although habitat selection and home range the relationships between habitat selection and home range size of 32 white- tailed deer (Odocoileus virginianus spatial patterns in canopy openings within forest stands. Deer responded to forage abundance at multiple

Laval, Université

127

Estuary Restoration Act Estuary Habitat Restoration Council  

E-print Network

Estuary Restoration Act Estuary Habitat Restoration Council Ranked Proposal Recommendation May 13 planting of a native sea urchin. Recommend NOAA fund 8. Salt Creek Estuary, Will remove portions of two it to its historic size of 77 acres. Recommend USACE fund. #12;9. Skokmish Estuary Will re

US Army Corps of Engineers

128

Why do juvenile fish utilise mangrove habitats?  

PubMed

Three hypotheses to discern the strong positive association between juvenile fish and mangrove habitat were tested with field and laboratory experiments. Artificial mangrove structure in the field attracted slightly more juvenile fish than areas without structure. Artificial structure left to accumulate fouling algae attracted four-times the total number of juvenile fish than areas without structure or areas with clean structure. Community composition of fish attracted to structure with fouling algae was different when compared with areas with no structure or clean structure; five species were attracted by structure with fouling algae whilst two species were associated with structure regardless of fouling algae. Algae were linked to increased food availability and it is suggested that this is an important selection criteria for some species. Other species were apparently attracted to structure for different reasons, and provision of shelter appears to be important. Predation pressure influenced habitat choice in small juvenile fish in laboratory experiments. In the absence of predators, small juveniles of four out of five species avoided shelter but when predators were introduced all species actively sought shelter. Large fish were apparently less vulnerable to predators and did not seek shelter when predators were added to their tank. Feeding rate was increased in the mangrove habitat for small and medium-sized fish compared with seagrass beds and mudflats indicating increased food availability or foraging efficiency within this habitat. Larger fish fed more effectively on the mudflats with an increased feeding rate in this habitat compared with adjacent habitats. The most important aspect of the mangrove habitat for small juvenile fish is the complex structure that provides maximum food availability and minimises the incidence of predation. As fish grow a shift in habitat from mangroves to mudflat is a response to changes in diet, foraging efficiency and vulnerability to predators. PMID:11245878

Laegdsgaard, P; Johnson, C

2001-03-15

129

Global patterns of fragmentation and connectivity of mammalian carnivore habitat  

PubMed Central

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

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

2011-01-01

130

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

131

NORTHWOODS Wildlife Habitat Database  

NSDL National Science Digital Library

Created through a joint effort of the USDA Forest Service's North Central Forest Experiment Station (NCFES) and seven national forests in the Upper Great Lakes Region, NORTHWOODS is a wildlife habitat database featuring "information about the habitat needs of 389 species of reptiles, amphibians, birds, and mammals in the Upper Great Lakes Region." The database compiles common and scientific names, species occurrences in 20 aquatic and terrestrial habitat types, species abundances and seasonal use in seven national forests, and species conservation status. The NORTHWOODS database is available in tab-delimited ASCII file format.

132

Food-web models predict species abundances in response to habitat change.  

PubMed

Plant and animal population sizes inevitably change following habitat loss, but the mechanisms underlying these changes are poorly understood. We experimentally altered habitat volume and eliminated top trophic levels of the food web of invertebrates that inhabit rain-filled leaves of the carnivorous pitcher plant Sarracenia purpurea. Path models that incorporated food-web structure better predicted population sizes of food-web constituents than did simple keystone species models, models that included only autecological responses to habitat volume, or models including both food-web structure and habitat volume. These results provide the first experimental confirmation that trophic structure can determine species abundances in the face of habitat loss. PMID:17002518

Gotelli, Nicholas J; Ellison, Aaron M

2006-10-01

133

Food-Web Models Predict Species Abundances in Response to Habitat Change  

PubMed Central

Plant and animal population sizes inevitably change following habitat loss, but the mechanisms underlying these changes are poorly understood. We experimentally altered habitat volume and eliminated top trophic levels of the food web of invertebrates that inhabit rain-filled leaves of the carnivorous pitcher plant Sarracenia purpurea. Path models that incorporated food-web structure better predicted population sizes of food-web constituents than did simple keystone species models, models that included only autecological responses to habitat volume, or models including both food-web structure and habitat volume. These results provide the first experimental confirmation that trophic structure can determine species abundances in the face of habitat loss. PMID:17002518

Gotelli, Nicholas J; Ellison, Aaron M

2006-01-01

134

Spectrum of Habitats  

NSDL National Science Digital Library

An overview of biodiversity and biodiversity gradients, this PDF presentation introduces students to the Earth's major habitats, discussing each one's role in the biosphere and how it is negatively impacted by human activity. The nine habitats covered through maps and text are: tundra, grasslands and savannas, temperate and boreal forests, tropical forests, coral reefs and coastal wetlands, deserts, freshwater wetlands, rivers, and lakes, oceans and islands.

135

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.

136

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

137

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

138

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

139

Northwest Habitat Institute Integrated Habitat and Biodiversity Information SystemIntegrated Habitat and Biodiversity Information System  

E-print Network

Northwest Habitat Institute Integrated Habitat and Biodiversity Information SystemIntegrated Habitat and Biodiversity Information System (IBIS) for the Columbia River Basin(IBIS) for the Columbia Program 15-36% of recommended funding #12;Regional strategy for managing fish, wildlife, and habitat data

140

Determinants of Habitat Selection by Hatchling Australian Freshwater Crocodiles  

PubMed Central

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

141

The distribution of groundwater habitats in Europe  

NASA Astrophysics Data System (ADS)

Globalization and planetary environmental changes have stimulated the inventory of groundwater resources and biodiversity at continental and global scales but there has been no concurrent attempt to map the distribution of groundwater habitats even at continental scale. A vector version of the areal information contained in the international hydrogeological map of Europe (IHME) was produced, and thematic indicators for assessing its accuracy were established. Then, groundwater flow type, permeability and pore size were extracted from the vector IHME to define and map the distribution of 13 habitat types. The habitat map was used to test for latitudinal variations in habitat diversity (HD) and whether these variations might in part account for the latitudinal gradient of regional species richness. The HD of river catchments decreased significantly with increasing latitude after correcting for the effect of catchment area. HD decreased by half the amount of deviance attributed to latitude in a regression model of regional species richness, although the explanatory power of HD was probably limited by the coarse resolution of biogeographical regions. The groundwater habitat map of Europe represents a major step for the understanding, assessment and conservation of groundwater biodiversity and for incorporating ecological perspectives in groundwater management policy.

Cornu, Jean-François; Eme, David; Malard, Florian

2013-08-01

142

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

143

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

144

Movements and habitat use of mallard broods in northeastern California  

USGS Publications Warehouse

To increase recruitment of mallards (Anas platyrhynchos), wildlife managers must understand the habitat and space needs of mallard broods. During 1989-90, we examined the movements, home range, and habitat use of 27 radio-marked mallard broods on Lower Klamath National Wildlife Refuge, California. Twelve of the 27 broods made 22 relocation movements (>1,000 m in 24 hr) in the first week (n = 6) and after the fourth (n = 16) week of life. Mean home range size was 0.93 km2 (SE = 0.25) and did not differ between years (P = 0.26). Brood-rearing females selected seasonally flooded wetlands with a cover component and avoided open or permanently flooded habitats. In 1989, broods hatched in permanent wetlands were less successful in fledging (P = 0.006) radio-marked ducklings than broods from seasonal wetlands, suggesting habitat availability or movement to preferred habitats may affect duckling survival.

Mauser, D.M.; Jarvis, R.L.; Gilmer, D.S.

1994-01-01

145

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; Boomer, G. S.; Clark, R. G.; Devers, P.; Eadie, J. M.; Lonsdorf, E. V.; Tavernia, Brian

2014-01-01

146

Habitat quality and range use of white-headed langurs in Fusui, China.  

PubMed

The socioecology of white-headed langurs (Trachypithecus leucocephalus) was studied in Fusui Precious Animal Reserve, Guangxi, China, in 1997/1998. Habitat quality was classified according to the level of human disturbance. Plant species diversity increased with habitat quality. Important foods for the langurs occurred more in high-quality habitat. Home range size varied from 28 to 48 ha, and the home range area per individual decreased as habitat quality increased. Small polygynous langur groups had poorly defended ranges, but large groups defended their ranges intensively. Only harem males were involved in group defence, apparently competing for females by defending their habitat. High-quality habitat was more attractive to females; accordingly, group size increased significantly with habitat quality. PMID:16088186

Li, Zhaoyuan; Rogers, M Elizabeth

2005-01-01

147

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

148

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

149

Habitat Relations Greater Sage-Grouse Winter Habitat Use on  

E-print Network

Habitat Relations Greater Sage-Grouse Winter Habitat Use on the Eastern Edge of Their Range sage-grouse (Centrocercus urophasianus) at the western edge of the Dakotas occur in the transition zone from those habitats that comprise the central portions of the sage-grouse range; yet, no information

150

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

151

Habitat use and preferences of breeding female wood ducks  

USGS Publications Warehouse

Female wood ducks (Aix sponsa) feed primarily on plant foods in the prelaying period and switch to a diet of mostly invertebrates during egg production. If nutrient acquisition is habitat-specific, then selection and use of habitats may differ between these reproductive stages. A better understanding of these processes is needed to assist future habitat conservation and management efforts. In January-May 1999 and 2000, we monitored movements and habitat use of radiomarked females (n = 47) during the prelaying and egg-production periods of first nests. Home-range size averaged 367 ha and did not vary with reproductive period, year, or female age. Habitat use did not differ between periods of prelaying and egg production; consequently, data were combined. Habitat use varied between years, female age, and periods of nest initiation (i.e., early vs. late). Use of beaver ponds (BP), temporary wetlands (TW), managed impoundments (MI), and lake habitats (LK) declined in 2000 compared to 1999, possibly due to reduced precipitation. Nest initiation date was independent of female age. Adult females used BP more than yearlings, and early-nesting females used BP and MI more than late-nesting females. Females selected habitats nonrandomly when habitat composition of the study area was compared to that of home ranges (second-order selection). Lake-influenced wetlands (LI) and MI were ranked highest in preference. Home-range size was inversely related to percentage of the home range comprised of MI and LI, supporting the idea that MI and LI were high-quality habitats. However, we found no relationship between nest initiation date (an important index to reproductive performance) and the combined area of MI and LI in home ranges. Habitai selection did not differ from random when habitat composition of home ranges was compared to that of radio locations (third-order selection). Although MI and LI were preferred, high-quality habitats, our results suggest that breeding female wood ducks can satisfy requirements for egg production using a variety of wetland habitats. We suggest that providing a diversity of habitat types will increase the probability of meeting needs of breeding females throughout the breeding season, especially in areas where wetland conditions frequently change.

Hartke, K.M.; Hepp, G.R.

2004-01-01

152

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

153

Linking habitat mosaics and connectivity in a coral reef seascape  

PubMed Central

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.

2012-01-01

154

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.

Science, Lawrence H.

1981-01-01

155

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...

156

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

157

Habitat Loss, Fragmentation, and Restoration  

Microsoft Academic Search

Abstract The loss and fragmentation of habitat is a major threat tothe continued survival of many species. We argue that, by including spatial processes in restoration management plans, the effects of habitat loss and fragmentation can be offset. Yet few management plans take into account spatial effects of habitat con- servation\\/restoration despite the importance of spatial

Gary R. Huxel; Alan Hastings

1999-01-01

158

Sage-grouse Habitats and  

E-print Network

Monitoring of Greater Sage-grouse Habitats and Populations Station Bulletin 80 October 2003 College-1142. Cover photograph by N.A. Burkepile #12;Monitoring of Greater Sage-grouse Habitats and Populations John W. Connelly Kerry P. Reese Michael A. Schroeder October 2003 #12;Monitoring of Greater Sage-grouse Habitats

Torgersen, Christian

159

How much habitat is enough?  

Microsoft Academic Search

If conservation efforts are to be successful, it is critical that we understand the relationship between habitat loss and the probability of population extinction. Available evidence suggests a threshold amount of habitat loss at which the probability of population extinction increases from near-zero to near-one following a small additional loss of habitat. The main factors thought to determine this extinction

L. Fahrig

2001-01-01

160

THE HABITAT CONCEPT IN ORNITHOLOGY  

E-print Network

CHAPTER 2 THE HABITAT CONCEPT IN ORNITHOLOGY Theory and Applications WILLIAM M. BLOCK and LEONARD A. BRENNAN 1. INTRODUCTION Ornithologists have played a key role in the development of the habitat concept]., 1989; Morrison et a].,1992). The application of the term "habitat" has been used as a unifying

161

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

162

A simulation study of the impacts of population subdivision on the mountain brushtail possum Trichosurus caninus Ogilby (Phalangeridae: Marsupialia), in south-eastern Australia. II. Loss of genetic variation within and between subpopulations  

Microsoft Academic Search

The subdivision of populations that results from habitat fragmentation can impact the amount and pattern of genetic variation in metapopulations of organisms. Subdivision can lead to a loss of heterozygosity, and increased inbreeding within subpopulations is one factor that may contribute to an extinction vortex. However, a number of genetic models have also shown that, under some conditions, subdivision of

D. B. Lindenmayer

1995-01-01

163

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

164

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.

Park, Smithsonian N.

2012-06-26

165

Integral habitat transport system  

NASA Technical Reports Server (NTRS)

In the 1993 Fall quarter, the ME 4182 design class was sponsored to study various scenarios that needed to be studied for Martian travel. The class was sponsored by NASA and there were several different design projects. The design that group three chose was an integral transport system for a Martian habitat. An integral transport system means the design had to be one that was attached to the habitat. There were several criteria that the design had to meet. Group three performed an in depth study of the Martian environment and looked at several different design ideas. The concept group three developed involved the use of kinematic linkages and the use of Martian gravity to move the habitat. The various design concepts, the criteria matrices and all other aspects that helped group three develop their design can be found in their 1993 ME 4182 design report. Now it is Winter quarter 1994 and group three is faced with another problem. The problem is building a working prototype of their Fall design. The limitations this quarter were the parts. The group had to make the prototype work with existing manufactured parts or make the parts themselves in a machine shop. The prototype was scaled down roughly about twelve times smaller than the original design. The following report describes the actions taken by group three to build a working model.

Elliott, Bill; Frazer, Scott; Higgs, Joey; Huff, Jason; Milam, Tigree

1994-01-01

166

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

167

SPATIAL DISTRIBUTION AND HABITAT CHARACTERIZATION OF ANOPHELINE MOSQUITO LARVAE IN WESTERN KENYA  

Microsoft Academic Search

Studies were conducted to characterize larval habitats of anopheline mosquitoes and to analyze spatial heterogeneity of mosquito species in the Suba District of western Kenya. A total of 128 aquatic habitats containing mosquito larvae were sampled, and 2,209 anopheline and 10,538 culicine larvae were collected. The habitats were characterized based on size, pH, distance to the nearest house and to

NOBORU MINAKAWA; CLIFFORD M. MUTERO; JOHN I. GITHURE; JOHN C. BEIER; GUIYUN YAN

168

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

169

Vacant habitats in the Universe.  

PubMed

The search for life on other planets usually makes the assumption that where there is a habitat, it will contain life. On the present-day Earth, uninhabited habitats (or vacant habitats) are rare, but might occur, for example, in subsurface oils or impact craters that have been thermally sterilized in the past. Beyond Earth, vacant habitats might similarly exist on inhabited planets or on uninhabited planets, for example on a habitable planet where life never originated. The hypothesis that vacant habitats are abundant in the Universe is testable by studying other planets. In this review, I discuss how the study of vacant habitats might ultimately inform an understanding of how life has influenced geochemical conditions on Earth. PMID:21146249

Cockell, Charles S

2011-02-01

170

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

171

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.

172

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.

173

50 CFR 622.302 - Minimum mesh size.  

Code of Federal Regulations, 2013 CFR

...ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Pelagic Sargassum Habitat of the South Atlantic Region § 622.302 Minimum mesh size. (a) The minimum allowable mesh size for a net...

2013-10-01

174

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.

175

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

176

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

177

Large viruses and infected microeukaryotes in Ross Sea summer pack ice habitats  

Microsoft Academic Search

A variety of Ross Sea summer pack ice habitats between 66 and 75°S were examined for viruses 𔒦 nm capsid diameter. Maximum abundances of these viruses likely to infect eukaryotes were 106-107 ml-1 brine in surface, interior, and bottom habitats and constituted up to 18% of the total (all sizes) viruses. There is abundant ultrastructural evidence for infection of a

M. M. Gowing

2003-01-01

178

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...

179

Cumulative impacts of seabed trawl disturbance on benthic biomass, production, and species richness in different habitats  

Microsoft Academic Search

Bottom trawling causes widespread disturbance of sediments in shelf seas and can have a negative impact on benthic fauna. We conducted a large-scale assessment of bottom trawl fishing of benthic fauna in different habitats, using a theoretical, size-based model that included habitat features. Species richness was estimated based on a generalized body mass versus species richness relationship. The model was

J. G. Hiddink; S. Jennings; M. J. Kaiser; A. M. Queiros; D. E. Duplisea; G. J. Piet

2006-01-01

180

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

181

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

182

Food technology in space habitats  

NASA Technical Reports Server (NTRS)

The research required to develop a system that will provide for acceptable, nutritious, and safe diets for man during extended space missions is discussed. The development of a food technology system for space habitats capable of converting raw materials produced in the space habitats into acceptable food is examined.

Karel, M.

1979-01-01

183

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

184

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

185

National Marine Fisheries Service Habitat Assessment  

E-print Network

:Background-PalmerSeamountbathymetricmap(NOAA,NOS).Photos(toptobottom)-swordspinerockfish resting in a sponge (SWFSC Fisheries Resources Division); juvenile fish in mangrove nursery habitat (Tom-recruit Functions Habitats, Movement, and Spatial Variation Capability of Stock Assessment Models to Include Habitat

186

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

187

Habitat Suitability Index Models: Longnose Dace  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for longnose dace (Rhinichthys cataractae), a freshwater fish. 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.

Edwards, Elizabeth A.; Li, Hiram; Schreck, Carl B.

1983-01-01

188

WILDLIFE HABITAT RELATIONS AND HABITAT FRAGMENTATION IV Section Overview Wildlife Habitat Relations and Habitat Fragmentation in California’s  

E-print Network

The nine papers in the following section on wildlife habitat relations and habitat fragmentation in hardwood rangelands from this symposium illustrate the wide diversity of these two research topics. With increasing humaninduced changes to California’s hardwood rangeland habitats, it is important that we understand how wildlife relate to these habitats and how wildlife are affected when habitat fragmentation occurs. This section provides some key sources of information in these areas. Wildlife Habitat Relations Three papers on bird communities (by Aigner and others, Tietje and others, Verner and others) and one paper on mammal communities (by Laudenslayer and Fargo) are excellent examples of the complexity of these communities and the difficulty in studying them. The papers by Aigner and others and Verner and others resulted from studies in which assessing the impacts of land management activities on birds was a major objective. While Verner and others reported on these impacts, both papers discussed many of the methodological problems associated with these types of studies. Furthermore, Verner and others noted that bird communities in a single grazed plot were relatively similar to those in a single ungrazed plot, although populations of two problematic birds, the brownheaded cowbird (Molothrus ater) and starling (Sturnus vulgaris), appeared to have increased with grazing. Two papers provided basic natural history information on nesting habitats of two raptorial birds, the red-tailed hawk (Buteo jamaicensis) (by Tietje and others) and California spotted owl (Strix occidentalis occidentalis) (by Steger and others). These two natural history studies provide extremely useful information to wildlife scientists and managers recommending and implementing actions intended to conserve these two important raptors. Structural components of hardwood rangeland habitats, such as logs and snags, are rarely studied, so the paper by Tietje and others on downed woody debris helps fill an obvious data gap. Data gaps for habitat components are particularly onerous because most conservation recommendations are directed at habitat components, not wildlife populations and communities.

Hardwood Rangelands; Barrett A. Garrison; Frank W. Davis

189

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

190

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

191

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

192

Monitoring the Conservation of Grassland Habitats, Prairie Ecozone, Canada  

Microsoft Academic Search

The Prairie Ecozone contains 5% of Canada's land area and represents 16% of the Great Plains of North America. Current estimates indicate that 25–30% of original Canadian grassland habitats remain, largely concentrated in southeastern Alberta and southwestern Saskatchewan with fragments distributed throughout southern Manitoba. The size, distribution and condition of native grasslands serve as valuable indicators of the ecological integrity

David A. Gauthier; Ed B. Wiken

2003-01-01

193

Habitat disturbance and the stability of freshwater gastropod populations  

Microsoft Academic Search

The interaction of population stability and habitat permanence has a major influence on the microdistribution of freshwater snails. For two years (February 1980–January 1982), we monitored the abundance of macrophytes and the abundance and size structure of four species of macrophyte-associated freshwater snails in an English pond. Previous work (Lodge, in press) showed that two species, the pulmonate Lymnaea peregra

D. M. Lodge; P. Kelly

1985-01-01

194

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

195

Evaluating Great Lakes Bald Eagle Nesting Habitat  

E-print Network

for bald eagles (Haliaeetus leucocephalus) along the five Great Lakes shorelines. We developed a pattern eagle, Bayesian inference, Great Lakes, habitat modeling, Haliaeetus leuco- cephalus, nesting habitat

196

Habitat-specific demography: evidence for source-sink population structure in a mammal, the pika.  

PubMed

Theory suggests that populations may persist in sink habitats that cannot support replacement-level birth rates. Although it is commonly believed that organisms that can actively select habitat should rarely occur in sinks, the frequency of use of sinks in free-ranging species is not well-documented. We found that a population of American pikas ( Ochotona princeps, Lagomorpha) inhabiting distinct alpine habitats (meadow and snowbed) in Wyoming, USA, had habitat-specific demographic rates that produced a source-sink population structure. Population size increased in both habitats in summer and declined in both habitats in winter, with populations in snowbeds increasing more during summer and decreasing more over winter. Birth rates were consistently higher in meadows and populations in meadows had a consistently higher finite rate of increase (lambda, from life tables) than did those in snowbeds, for which lambda was far below that needed for replacement. Patterns of immigration, population structure, and temporal variation in population size were as expected if meadows were functional sources and snowbeds functional sinks. Patterns of snowmelt differed between habitats, predicted the critical difference in birth rates between habitats, and are a likely primary cause of the differences in habitat-specific birth rates that we observed. This study provides a clear example of source-sink population structure for a mammal. PMID:12647141

Kreuzer, M P; Huntly, N J

2003-02-01

197

Population and habitat dynamics of the white-footed mouse (Peromyscus leucopus) in a heterogeneous forest  

SciTech Connect

Movements and demography of white-footed mice (Peromyscus leucopus) were determined by live-trapping and radiotelemetry in contiguous upland and lowland forest habitat to assess the extent of variation in local habitat distribution due to season, age, and sex factors. Mice were marked and recaptured monthly in 1980 and 1981 from April through December on a continuous 20 ha trapping grid, thus yielding 1486 captures of 397 individuals. Locations and activity of 43 mice were determined by radiotracking. Various measures of habitat suitability, including adult density, sex ratio, reproduction, persistence, home range size, and immigration, indicated a seasonal cycle of habitat suitability. Upland habitat appeared better for overwintering, and lowland habitat was superior relative to the upland from June through October. Tendencies for breeding females to be restricted to lowland, and for lowland males to display greater mean body weights and smaller home range sizes than upland males, were attributed to greater food availability in the lowland over this period. Individual P. leucopus use local habitats opportunistically, but variations in habitat distribution between the age- and sex-classes of the population noted during the breeding season suggest that local habitats provide a spatial framework for behavioral population regulation in P. leucopus. 49 references, 5 figures, 10 tables.

Ormiston, B.G.

1984-07-01

198

Rare species, habitat diversity and functional redundancy in marine benthos  

NASA Astrophysics Data System (ADS)

Macro-ecological theories relating species richness, abundance, range size, biological traits and environmental tolerance have rarely been tested in marine soft-sediments, despite the spatial extent of these habitats and the inherent richness of resident communities. This study examines the contribution of rare species to marine soft-sediment communities from New Zealand, focussing on the relationships of range size with abundance, environment, habitat diversity and life history traits. 54% of the 351 species sampled exhibited restricted ranges (found at ? 2 sites). In contrast to many terrestrial systems, we observed only a weak positive relationship between abundance and frequency of occurrence. Restricted-range species were not randomly distributed, with their distribution related to habitat characteristics, suggesting an important link between habitat diversity and rarity. They exhibited a similar range of traits to the total observed species pool, suggesting that they are not only important to biodiversity but could play a role in stability. Restricted range species were generally not small and this, together with the number of different biological traits represented, suggests that rare species are important to the functioning of marine systems. Thus, our results highlight the importance of considering rare species in habitat-based approaches to conservation.

Ellingsen, Kari E.; Hewitt, Judi E.; Thrush, Simon F.

2007-11-01

199

Short Research Note Habitat-dependent ecotype micro-distribution at the mid-shore  

E-print Network

and barnacles) obtained for three seasons in three consecutive years and three localities. In the mid and habitats: the large-sized ridged and banded eco- type (RB) is found among barnacles on the upper shore

Rolán-Alvarez, Emilio

200

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

201

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...

202

Habitat use of American eel (Anguilla rostrata) in a tributary of the Hudson River, New York  

USGS Publications Warehouse

American eel Anguilla rostrata populations are declining over much of their native range. Since American eels spend extended periods in freshwater, understanding their habitat requirements while freshwater residents is important for the management and conservation of this species. As there is little information on American eel habitat use in streams, the ontogenetic, diel, and seasonal habitat use as well as habitat selectivity of three size groups (i.e. ?199 mm total length, 200–399 mm, ?400 mm) of eel were examined in a tributary of the Hudson River. American eels in Hannacroix Creek exhibited ontogenetic, diel, and seasonal variation in habitat use as well as habitat selection. During both summer and autumn all sizes of American eels used larger substrate and more cover during the day. American eels ?199 mm exhibited the strongest habitat selection, whereas eels 200–399 mm exhibited the least. During the autumn all sizes of American eels occupied slower depositional areas where deciduous leaf litter accumulated and provided cover. This may have important implications for in-stream and riparian habitat management of lotic systems used by American eel.

Johnson, James H.; Nack, Christopher C.

2013-01-01

203

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

204

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

205

Landscape modification and habitat fragmentation: a synthesis  

Microsoft Academic Search

ABSTRACT Landscape modification and habitat fragmentation are key drivers of global species loss. Their effects may be understood by focusing on: (1) individual species and the processes threatening them, and (2) human-perceived landscape patterns and their correlation with species and assemblages. Individual species may decline as a result ofinteracting exogenous and endogenous threats, including habitat loss, habitat degradation, habitat isolation,

Joern Fischer; David B. Lindenmayer

2007-01-01

206

The Habitat Organization Oct. 6, 06, 2006  

E-print Network

The Habitat Organization Oct. 6, 06, 2006 spent $1.4 million to improve anadromous fish habitat within the watershed. The funds have been spent to improving habitat, and have completed a tremendous amount of habitat implementation within the past three

207

Habitat Fragmentation and Edge Effects Definition  

E-print Network

Habitat Fragmentation and Edge Effects Topics: ·Definition ·Root in Island Biogeography ·Ecological 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

Hansen, Andrew J.

208

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

209

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

210

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

211

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 �levé Faible Perte d'habitat

Blouin-Demers, Gabriel

212

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.

213

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

214

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

215

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

216

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

217

Habitat Suitability Index Models: Ruffed Grouse  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the ruffed grouse (Bonasa umbellus). 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.; Sousa, Patrick J.

1985-01-01

218

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

219

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

220

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

221

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

222

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

223

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

224

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

225

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

226

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

227

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

228

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

229

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

230

Why is group size correlated with the size of the host sea anemone in the false clown anemonefish?  

Microsoft Academic Search

When social groups monopolize discrete habitat patches, group size may be positively correlated with patch size. The correlation can be a direct consequence of limited resources. Alternatively, it can be an indirect consequence of patch-size effects on a dominant group member. We asked which of these two mechanisms was responsible for a positive correlation between the group size of false

Jeremy S. Mitchell; Lawrence M. Dill

2005-01-01

231

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

232

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

233

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

234

Effects of Life History Strategy on Fish Distribution and Use of Estuarine Salt Marsh and Shallow-Water Flat Habitats  

Microsoft Academic Search

To assess the potential for habitat isolation effects on estuarine nekton, we used two species with different dispersal abilities\\u000a and life history strategies, mummichog (Fundulus heteroclitus) and pinfish (Lagodon rhomboides) to examine: (1) distribution trends among estuarine shallow-water flat and various intertidal salt marsh habitats and (2)\\u000a the influence of salt marsh habitat size and isolation. Collections were conducted using

David L. Meyer; Martin H. Posey

2009-01-01

235

Habitat choice by juvenile cod ( Gadus morhua L.) on sandy soft bottoms with different vegetation types  

NASA Astrophysics Data System (ADS)

Habitat choice by juvenile cod ( Gadus morhua L.) on sandy bottoms with different vegetation types was studied in laboratory. The experiment was conducted day and night in flow-through tanks on two different size-classes of cod (7-13 and 17-28 cm TL). Four habitats, typical of shallow soft bottoms on the Swedish west coast: Fucus vesiculosus, Zostera marina, Cladophora sp. and bare sand, were set up pair-wise in six combinations. The main difference between habitats in this study was vegetation structure, since all parameters except vegetation type was considered equal for both sides of the experimental tanks and natural prey was eliminated. The results showed a difference in habitat utilization by juvenile cod between day (light) and night (dark). During day time the fishes showed a significant preference for vegetation, while nocturnally no significant choice of habitat was made. Both size-classes preferred Fucus, considered the most complex habitat in this study, when this was available. The smaller size-class seemed to be able to utilize the other vegetation types as well, always preferring vegetation over sand. Larger juvenile cod, on the other hand, appeared to be restricted to Fucus. This difference in habitat choice by the two size-classes might be due to a greater dependence on shelter from predation by the smaller juveniles, causing them to associate more strongly with vegetation. The larger juveniles avoided Cladophora, since they might have difficulties in entering the compact structure of this filamentous algae. Availability of vegetation at day time, as a predation refuge, as well as of open sandy areas for feeding during night, thus seems to be important for juvenile cod. It is concluded that eutrophication-induced changes in habitat structure, such as increased dominance by filamentous algae, could alter the availability of predation refuges and foraging habitats for juvenile cod.

Borg, Å.; Pihl, L.; Wennhage, H.

1997-08-01

236

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

237

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

238

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

239

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

240

Habitat selection by tundra swans on Northern Alaska breeding grounds  

USGS Publications Warehouse

Habitat selection by the Tundra Swan (Cygnus columbianus columbianus) was evaluated on the Colville River Delta prior to oil field development (1982-1989). Tundra Swan territories comprised a lake, used for refuge and foraging, and terrestrial habitats and ponds near the lakea??s perimeter used for foraging and nesting. Tundra swan sightings from early and late summer aerial surveys were used to investigate habitat selection at the territory and within-territory scale. At the territory or lake scale, swan sightings/lake increased with lake size, and increased from discrete to tapped (i.e., connected to a river channel) to drained lakes within size categories. Overall, 49% of the variation in swan sightings/lake was explained by lake size and type, a size-x-type interaction term, and the proportion of lake perimeter comprised of Halophytic Ponds and Halophytic Wet Meadows. At the within-territory or within-lake scale, foraging swans significantly selected Halophytic Ponds, Halophytic Wet Meadows, and Fresh Ponds relative to Uplands; nesting swans significantly selected Halophytic Ponds and significantly avoided Fresh Wet Meadows relative to Uplands. Vegetation sampling indicated that sites used by Tundra Swans on river channels and tapped lakes were significantly more likely to have Sheathed Pondweed (Potamogeton vaginatus) than control sites. The three major components of Tundra Swan diet were Carex sedges, Sheathed Pondweed, and algae, together comprising 85% of identifiable plant fragments in feces.

Earnst, Susan L.; Rothe, T.

2004-01-01

241

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

242

Functional morphology of the bovid astragalus in relation to habitat: controlling phylogenetic signal in ecomorphology.  

PubMed

Bovid astragali are one of the most commonly preserved bones in the fossil record. Accordingly, astragali are an important target for studies seeking to predict the habitat preferences of fossil bovids based on bony anatomy. However, previous work has not tested functional hypotheses linking astragalar morphology with habitat while controlling for body size and phylogenetic signal. This article presents a functional framework relating the morphology of the bovid astragalus to habitat-specific locomotor ecology and tests four hypotheses emanating from this framework. Highly cursorial bovids living in structurally open habitats are hypothesized to differ from their less cursorial closed-habitat dwelling relatives in having (1) relatively short astragali to maintain rotational speed throughout the camming motion of the rotating astragalus, (2) a greater range of angular excursion at the hock, (3) relatively larger joint surface areas, and (4) a more pronounced "spline-and-groove" morphology promoting lateral joint stability. A diverse sample of 181 astragali from 50 extant species was scanned using a Next Engine laser scanner. Species were assigned to one of four habitat categories based on the published ecological literature. A series of 11 linear measurements and three joint surface areas were measured on each astragalus. A geometric mean body size proxy was used to size-correct the measurement data. Phylogenetic generalized least squares (PGLS) was used to test for differences between habitat categories while controlling for body size differences and phylogenetic signal. Statistically significant PGLS results support Hypotheses 1 and 2 (which are not mutually exclusive) as well as Hypothesis 3. No support was found for Hypothesis 4. These findings confirm that the morphology of the bovid astragalus is related to habitat-specific locomotor ecology, and that this relationship is statistically significant after controlling for body size and phylogeny. Thus, this study validates the use of this bone as an ecomorphological indicator. PMID:25042704

Barr, W Andrew

2014-11-01

243

Estimating the habitat potential of inland forest patches for birds using a species–area curve model  

Microsoft Academic Search

Estimating the habitat potential of inland forest patches for birds requires the modeling of species–area relationships, or relationships between habitat size and numbers of bird species in each patch. The accurate estimation of species–area relationships significantly reduces the effort required to recognize the number of species living in each patch. The objective of this study was to estimate the relationship

O. S. Chung; G. S. Jang; J. H. Oh

2011-01-01

244

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

245

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

246

Autumnal habitat use of non-native pumpkinseed Lepomis gibbosus and associations with native fish species in small English streams  

Microsoft Academic Search

A b s t r a c t. Habitat use of introduced pumpkinseed Lepomis gibbosus in small European streams has received little study despite the species' potential associations to native fauna of conservation and angling amenity, e.g. brook lamprey Lampetra planeri, European bullhead Cottus gobio, brown trout Salmo trutta. We examined body size, relative body condition, habitat use and species-species

Megan KLAAR; Gordon H. COPP; Richard HORSFIELD

2004-01-01

247

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.

1999-01-01

248

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

249

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

250

Movements of wintering Dunlin Calidris alpina and changing habitat availability in an agricultural wetland landscape  

USGS Publications Warehouse

Few studies have assessed how the dynamics of wetland bird movements relate to changing resource availability, particularly at more than one spatial scale. Within western Oregon's Williamette Valley, we examined winter resident Dunlin Calidris alpina movements in relation to a decrease in availability of preferred shorebird foraging habitat from early to late winter of 1999-2000. By tracking movements of 15 (early winter) and 12 (late winter) radiomarked individuals, we calculated home ranges and characterized presence/absence of a preference for shorebird foraging habitat during each winter period. Between periods, we compared: (1) percentage of shorebird habitat in home ranges to its availability in the landscape (regional preference), (2) percentage of radio locations in shorebird habitat to its availability within home ranges (local preference) and (3) relative use of roost sites. Concurrent with a 75% decrease in available shorebird habitat from early to late winter, average home range sizes increased by a factor of 3.8. At a regional scale, home ranges in early winter included a significantly greater percentage of shorebird foraging habitat than was available in the wider landscape. However, by late winter, the percent of shorebird habitat in home ranges did not match availability in the landscape. At the local scale, for both winter periods Dunlin were located in shorebird foraging habitat more often than expected given availability of habitat within home ranges [Correction added after online pub-lication 23 May 2008: sentence amended]. An increase in the number of roosts used from early to late winter implies possible reliance on additional sites in late winter for foraging opportunities. Results suggest that wet, unvegetated habitat is sought by Dunlin throughout winter, but individuals could not select home ranges in late winter that fully compensated for seasonal loss of habitat. ?? 2008 The Authors.

Taft, O.W.; Sanzenbacher, P.M.; Haig, S.M.

2008-01-01

251

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

252

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

253

PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY  

EPA Science Inventory

PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY The main objective of this study is to develop criteria for eelgrass habitat establishment and persistence within the Peconic Estuary utilizing various environmental analyses. The Program evaluated water and sediment quality data to...

254

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...

255

Glasgow and Clyde Valley Integrated Habitat Networks  

E-print Network

in the loss and fragmentation of semi-natural habitats and a subsequent reduction in biodiversity fragmentation of biodiversity and aid connectivity of semi natural habitats. BEETLE model analysis has been well

256

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

257

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

258

Habitat continuity and geographic distance predict population genetic differentiation in giant kelp.  

PubMed

Isolation by distance (IBD) models are widely used to predict levels of genetic connectivity as a function of Euclidean distance, and although recent studies have used GIS-landscape ecological approaches to improve the predictability of spatial genetic structure, few if any have addressed the effect of habitat continuity on gene flow. Landscape effects on genetic connectivity are even less understood in marine populations, where habitat mapping is particularly challenging. In this study, we model spatial genetic structure of a habitat-structuring species, the giant kelp Macrocystis pyrifera, using highly variable microsatellite markers. GIS mapping was used to characterize habitat continuity and distance between sampling sites along the mainland coast of the Santa Barbara Channel, and their roles as predictors of genetic differentiation were evaluated. Mean dispersal distance (sigma) and effective population size (Ne) were estimated by comparing our IBD slope with those from simulations incorporating habitat continuity and spore dispersal characteristics of the study area. We found an allelic richness of 7-50 alleles/locus, which to our knowledge is the highest reported for macroalgae. The best regression model relating genetic distance to habitat variables included both geographic distance and habitat continuity, which were respectively, positively and negatively related to genetic distance. Our results provide strong support for a dependence of gene flow on both distance and habitat continuity and elucidate the combination of Ne and a that explained genetic differentiation. PMID:20380195

Alberto, Filipe; Raimondi, Peter T; Reed, Daniel C; Coelho, Nelson C; Leblois, Raphael; Whitmer, Allison; Serrão, Ester A

2010-01-01

259

Seasonal habitat use of brook trout and juvenile Atlantic Salmon in a Tributary of Lake Ontario  

USGS Publications Warehouse

The seasonal habitat use of Salvelinus fontinalis (Brook Trout) and subyearling Salmo salar (Atlantic Salmon) was examined in Hart Brook, a tributary of Lake Ontario. Fish habitat use and available habitat were examined during summer and autumn. Interspecific differences in habitat use occurred as well as intraspecific seasonal differences. Overyearling Brook Trout were more selective in their habitat preferences than subyearling Brook Trout or juvenile Atlantic Salmon. Depth and the amount of cover were significantly different among the three fish groups. Salmon occupied faster and shallower water than either age group of trout. Atlantic Salmon were also associated with larger-sized substrate materials than either trout age group, and salmon occurred in habitats with less cover than trout. Overyearling Brook Trout occupied deeper water with more cover than subyearling trout. All three salmonid groups occupied areas with more cover in autumn compared to summer. In autumn, subyearling Brook Trout used deeper areas than they had in the summer. In Hart Brook, the habitat of subyearling Atlantic Salmon can be generally characterized as riffles, the habitat of overyearling Brook Trout was deep pools with extensive cover (35%), and that of subyearling trout was any area with moderate flow and at least 20% cover. As efforts proceed to reintroduce Atlantic Salmon in Lake Ontario, further research is needed to ensure the conservation of Brook Trout populations.

Johnson, J.H.

2008-01-01

260

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

261

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).

262

The ecology of urban habitats  

Microsoft Academic Search

This book provides an overview of the structure and function of urban ecosystems as well as a summary of existing information on specific urban habitats. The introduction and first four chapters of the book review characteristics of urban flora and fauna, urban climate and air pollution, soils and vegetation dynamics. The remaining 11 chapters cover the ecology and management of

O. L. Gilbert

1989-01-01

263

Do Habitat Corridors Provide Connectivity?  

Microsoft Academic Search

Skeptics have questioned the empirical evidence that corridors provide landscape connectivity. Some also have suggested dangers of corridors. We reviewed published studies that empirically addressed whether corridors enhance or diminish the population viability of species in habitat patches connected by cor- ridors. A randomized and replicated experimental design has not been used—and we argue is not required— to make inferences

Paul Beier; Reed F. Noss

1998-01-01

264

Habitat destruction in mutualistic metacomunities  

E-print Network

arbitrarily small decrease in the amount of habitat h below this value ..... 5(a) and (b) show the results of spatial Monte-. Carlo simulations of the dynamics of such a metacom- munity of 4 mutualists, 2 in .... J. Animal Ecol. 63, 490–491. Dytham ...

2004-01-16

265

Importance of early successional habitat to ruffed grouse and American woodcock  

USGS Publications Warehouse

Ruffed grouse (Bonasa umbellus) and American woodcock (Scolopax minor) provide millions of days of recreation each year for people in the eastern United States (U.S). These popular game birds depend on early successional forest habitats throughout much of the year. Ruffed grouse and woodcock populations are declining in the eastern United States as an abundance of shrub-dominated and young forest habitats decrease in most of the region. Continued decreases in early successional forest habitats are likely on nonindustrial private forest lands as ownership fragmentation increases and tract size decreases and on public forest lands due to societal attitudes toward proactive forest management, especially even-age treatments.

Dessecker, D.R.; McAuley, D.G.

2001-01-01

266

Simulation of Flow Regimes to Reduce Habitat for T. tubifex  

USGS Publications Warehouse

Whirling disease has had a significant impact on trout fisheries of the American west by reducing the numbers and quality of rainbow trout in infected streams. A critical factor in the life cycle of the whirling disease parasite is the fine sediment that provides the optimum habitat for Tubifex tubifex, an oligochaete worm that acts as an intermediate host for the disease. This report presents a model for the simulation of flushing flows required to remove undesirable fines and sand from a pool. Undesirable fines may also need to be flushed from runs, the surface layer, and backwater areas. Well-defined links of specific particle sizes to oligochaete worm abundance is needed to justify the use of flushing flows to move sediment. An analytical method for estimating the streamflows needed to remove the fine sediment is demonstrated herein. The overall steps to follow in removing fines from a stream are: Step 1. Determine size of the sediment that is the habitat for oligochaete worms. Step 2. Determine location of the sediment that is the habitat for oligochaete worms. Step 3. Determine streamflows needed to flush (remove) the sediment that is the habitat for oligochaete worms. The case study approach is used to present the method and to demonstrate its application. The case is derived from the sediment and oligochaete worm habitat of Willow Creek, a tributary of the Upper Colorado River located in Grand County, Colo. Willow Creek Reservoir (an element of the Colorado-Big Thompson Project) controls the streamflows of the creek and is just above the study site.

Milhous, Robert T.

2008-01-01

267

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

268

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

269

78 FR 61293 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Brickellia...  

Federal Register 2010, 2011, 2012, 2013

...provide anchoring and nutritional requirements to be a...habitat patch size to support a sustaining population...that larger areas will support larger populations and...size and quality to support populations), in sufficient...Minerals, or Other Nutritional or Physiological...

2013-10-03

270

Effects of habitat fragmentation on the red squirrel, Sciurus vulgaris L  

Microsoft Academic Search

The effects of woodlot size and isolation, in relation to habitat fragmentation, on the distribution of the red squirrel were studied. In The Netherlands, 50 woodlots (0.55–13.78 ha) were surveyed in an agricultural landscape for the presence of red squirrel. In 26 woodlots squirrel dreys (nests) were found. Logit regression analysis showed that woodlot size and the area per woodlot

B. Verboom; R. van Apeldoorn

1990-01-01

271

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

272

OPTIMUM BENTHIC MACROFAUNAL SAMPLING PROTOCOL FOR DETECTING DIFFERENCES BETWEEN FOUR HABITATS IN WILLAPA BAY, WASHINGTON, USA  

EPA Science Inventory

Abstract -- As part of an effort to estimate estuarine habitat values with respect to ecological indicators of benthic macrofaunal community condition, an optimal (effective and least costly) sampling protocol (sample unit size [area 3 depth], sieve mesh size, and sample number [...

273

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.

274

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

275

Habitat preservation and restoration: Do homebuyers have preferences for quality habitat?  

Microsoft Academic Search

This research examines homebuyers' preferences for nearby riparian habitat, an important issue because quality riparian habitat competes for water resources with other activities in semi-arid regions and because federal and local governments allocate significant resources to riparian habitat preservation and restoration plans. Riparian vegetation surveys comprising comprehensive measures of the ecological characteristics of riparian habitat were completed in the metropolitan

R. H. Bark; D. E. Osgood; B. G. Colby; G. Katz; J. Stromberg

2009-01-01

276

INTELLIGENCE PHYSIQUE DANS L'HABITAT 1 Intelligence physique dans l'habitat  

E-print Network

INTELLIGENCE PHYSIQUE DANS L'HABITAT 1 Intelligence physique dans l'habitat Michele Dominici Equipe. Contact : Michele.Dominici@inria.fr Résumé Les solutions d'habitat intelligent existantes adoptent une sont déclenchés par des échanges significatifs d'information. Cet article rappelle les concepts d'habitat

Paris-Sud XI, Université de

277

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

278

Morphology and habitat use by fishes of the Rio das Velhas basin in southeastern Brazil  

Microsoft Academic Search

We analyzed the morphology and habitat use of 16 small-sized fish species that are abundant in the Rio das Velhas basin using\\u000a 17 morphological attributes. Habitat use was characterized in terms of the species mean density considering three hydraulic\\u000a factors: substrate, water depth and mean water velocity. The distribution of species within the morphological space demonstrated\\u000a congruence between the morphological

Cecília Gontijo Leal; Nara Tadini Junqueira; Paulo Santos Pompeu

2011-01-01

279

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

280

Migratory bird habitat monitoring through remote sensing  

Microsoft Academic Search

Unsupervised classification of Landsat-TM data was employed to identify habitats important for migratory birds in Costa Rica. The overall habitat classification accuracy was 70 per cent (Kappa correction). Mature forest could be identified with high accuracy (93 per cent) but Landsat-TM classification accuracy for major successional stages was low. Habitat availability and conversion rates from 1976 to 1986 were derived

STEVEN A. SADER; GEORGE V. N. POWELL; JOHN H. RAPPOLE

1991-01-01

281

Regional Habitat Assessment Prioritization for California Stocks  

E-print Network

Regional Habitat Assessment Prioritization for California Stocks Report of the Southwest Regional://www.st.nmfs.noaa.gov/ecosystems/habitat/index This publication may be cited as: NMFS. 2012. Regional habitat assessment prioritization for California stocks.................................................................................................................................................1 Creating the Southwest Region Stock List

282

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

283

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 the potential to affect plants,animals and humans around the globe. #12;Climate Change Action Pack 158 Habitat out in shapes of hills, waves, leaves, and berries. #12;Climate Change Action Pack 159 PROCEDURE

Gunawardena, Arunika

284

Management Alternatives for the Riparian Habitat  

E-print Network

Management Alternatives for the Riparian Habitat in the Southwestl Gary A. Davis ~/ Abstract -- Exploitation, by man, has significantly al tered the riparian habitat in the Southwest. For decades, the primary or dominant use of riparian habitat has been water management; other values were ternatives

285

50 CFR 17.94 - Critical habitats.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Critical habitats. 17.94 Section 17.94 Wildlife...Interagency Cooperation § 17.94 Critical habitats. (a) The areas listed in § 17...determined by the Director to be Critical Habitat. All Federal agencies must...

2013-10-01

286

50 CFR 17.94 - Critical habitats.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Critical habitats. 17.94 Section 17.94 Wildlife...Interagency Cooperation § 17.94 Critical habitats. (a) The areas listed in § 17...determined by the Director to be Critical Habitat. All Federal agencies must...

2010-10-01

287

50 CFR 17.94 - Critical habitats.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Critical habitats. 17.94 Section 17.94 Wildlife...Interagency Cooperation § 17.94 Critical habitats. (a) The areas listed in § 17...determined by the Director to be Critical Habitat. All Federal agencies must...

2011-10-01

288

Estuary Habitat Restoration Council ACTION PLAN  

E-print Network

Estuary Habitat Restoration Council ACTION PLAN 2012 The purpose of this Action Plan is to support the 2012 Estuary Habitat Restoration (EHR) Strategy by identifying specific actions and milestones Service (NRCS). Several federal agencies fund and implement coastal and estuarine habitat restoration

US Army Corps of Engineers

289

Habitat for Humanity JOHNS HOPKINS UNIVERSITY  

E-print Network

2011 Habitat for Humanity JOHNS HOPKINS UNIVERSITY PRE-ORIENTATION P R O G R A M JHU and Sandtown The JHU campus chapter partners with Sandtown Habitat for Humanity (our local affiliate) to aid stand interspersed with long-abandoned and deteriorating ones. Habitat for Humanity undertakes complete

Connor, Ed

290

EUNIS habitat classification – a guide for users  

E-print Network

The EUNIS habitat classification is a comprehensive system covering the terrestrial and marine habitat types of the European land mass and its surrounding seas. It is hierarchical in structure and includes a key with criteria for identification of habitats at the first three levels. The underlying database and interface via the EUNIS website include text descriptions and

Dorian Moss

2008-01-01

291

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

292

50 CFR 17.94 - Critical habitats.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Critical habitats. 17.94 Section 17.94 Wildlife...Interagency Cooperation § 17.94 Critical habitats. (a) The areas listed in § 17...determined by the Director to be Critical Habitat. All Federal agencies must...

2012-10-01

293

Planning for Lowland Habitat Networks in Scotland  

E-print Network

Planning for Lowland Habitat Networks in Scotland: a landscape-scale approach Darren Moseley of semi-natural habitats and a reduction in biodiversity. Conservation policy and practice now seek that the development of habitat networks will not only benefit biodiversity but also deliver a range of other

294

Habitat patterns in a small mammal community  

Microsoft Academic Search

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

J. T. Kitchings; D. J. Levy

1981-01-01

295

Habitats: Making Homes for Animals and Plants.  

ERIC Educational Resources Information Center

This book of activities is designed to supplement a child's outdoor experiences and to encourage children to take a closer look at nature by creating temporary mini-habitats at home or in school. An introduction explains to students the concept of habitat and the responsibilities of keeping a mini-habitat. The remainder of the book contains…

Hickman, Pamela M.

296

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

297

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

298

Attributes of Natural Enemies in Ephemeral Crop Habitats  

Microsoft Academic Search

Ephemeral habitats differ from perennial habitats by their temporal and spatial continuity. The ephemeral habitats that compose annual crops impose constraints on the herbivorous pests and their natural enemies that exploit such habitats. Biological control theory that is based largely on the experiences and successes associated with perennial habitats may not align with opportunities that exist in ephemeral crop habitats.

Robert N. Wiedenmann; J. W. Smith

1997-01-01

299

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.

300

Potential intertidal habitat restoration sites in the Duwamish River estuary  

SciTech Connect

Restoration of wetland habitats in highly urbanized areas is generally constrained by scarcity of opportunity, adverse impacts of surrounding land use, and cost. Although areal wetland losses approach 98% in Seattle's Duwamish River estuary, the system continues to support important salmonid runs, as well as a variety of bird and mammal species. Estuarine-dependent organisms are likely limited by quality and quantity of intertidal habitat in the system. Because the long-range, estuary-wide benefit of site-specific mitigation and restoration projects is limited, it is imperative to develop estuary-wide restoration plans. Towards this end, an inventory and analysis of potential intertidal habitat restoration sites has been completed for the Duwamish River estuary. Twenty-four sites, ranging in size from 0.8 to 25 acres were identified and comparative functional potential assessed. The majority of these sites (18) occur in the upper estuary. Two sites are located in Elliott Bay, and four are located near the historic mouth of the river in the vicinity of Harbor Island. Spatial data have been developed in geographic information system (GIS) format. Other site-specific data relative to habitat restoration has also been assembled.

Tanner, C.D.

1991-12-01

301

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

USGS Publications Warehouse

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

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

2000-01-01

302

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

303

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

304

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

305

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

306

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

307

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

308

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.

Nerz, Joachim

2002-06-18

309

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

310

Survival and habitat of Ruffed Grouse nests in northern Michigan  

USGS Publications Warehouse

Effective management of Ruffed Grouse (Bonasa umbellus) populations requires a full understanding of chick production. Previous reports of nest survival for Ruffed Grouse are biased because they did not account for successful nests being more likely to be found, and the role of habitat quality in determining nest survival is unknown. We determined survival rates of Ruffed Grouse nests in northern lower Michigan using the less biased Mayfield estimator, defined differences between first and second nests, and compared the local habitat characteristics of successful and unsuccessful nests. Median hatching dates were 10 June for first nests (n = 34) and 1 July for second nests (n = 6). First nests had a lower survival rate (0.442, 95% CI = 0.270-0.716), a higher mean clutch size (12.7 eggs ?? 0.3 SE), and higher egg hatching rate (0.960, 95% CI = 0.900-0.997) than did second nests (nest survival = 0.788, 95% CI = 0.491-1.00; clutch size = 7.3 eggs ?? 0.3 SE; and hatching rate = 0.826, 95% CI = 0.718-0.925). Nest survival, annual production (3.4 hatchling females/adult female, 95% CI = 2.3-5.0), and fall recruitment (1.0 juvenile females/adult female, 95% CI = 0.3-2.4) were less than previously reported estimates. Habitat characteristics at nest sites varied widely and did not differ appreciably between successful and unsuccessful nests.

Larson, M.A.; Clark, M.E.; Winterstein, S.R.

2003-01-01

311

Habitat use and deconstruction of richness patterns in Cerrado birds  

NASA Astrophysics Data System (ADS)

At lower spatial scales, richness spatial patterns probably lead to more complex ecological-evolutionary interactions. In this paper, we used a "deconstruction" approach to evaluate the Cerrado breeding bird's richness, according to their habitat use categories (independent, semi-dependent and dependent on forest habitats). Six environmental variables and current human population size were used as predictors of species richness. Moran's I coefficients revealed strong spatial autocorrelation in ordinary least squares multiple regression residuals, and thus a Principal Coordinate of Neighbour Matrices (PCNM) was used to evaluate the influence of richness predictors, minimizing the problems caused by spatial autocorrelation. Models generated for total richness and for species richness by habitat categories were compared. We showed that, despite the total richness being more concentrated in south and southeast regions of Cerrado, these patterns changed when analysing semi-dependent and dependent forest habitat species, demonstrating a spatial variation in richness for these categories. The PCNM analyses demonstrated that, for total species richness, only partial coefficients of AET and temperature were significant. For independent forest richness, significant partial regression coefficients were found for AET, PET, TEMP and PREC, whereas for semi-dependent forest habitats richness, only AET was significant. On the other hand, for dependent of forest richness, a significant positive coefficient was found for precipitation and for human population. Most spatial variation in richness can be explained by joined effects of geographic structure and environmental predictors. These analyses reveal that deconstruction can be a step to a more effective understanding of richness patterns and their environmental drivers.

Blamires, Daniel; de Oliveira, Guilherme; de Souza Barreto, Bruno; Diniz-Filho, José Alexandre Felizola

2008-01-01

312

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

313

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

314

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

315

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.

Millette, Katie L; Keyghobadi, Nusha

2015-01-01

316

How much habitat management is needed to meet mallard production objectives?  

USGS Publications Warehouse

We used results from simulation models to demonstrate the benefit-cost ratios of habitat management to increase the number of mallard (Anas platyrhynchos) recruits produced. The models were applied to hypothetical 2-habitat landscapes comprised of managed and unmanaged habitat. Managed habitats were predator barrier fencing and CRP cover; unmanaged habitat was grassland. As the amount of managed cover increased, the production curve rose rapidly and leveled off. If 2 managed habitats are added to a landscape, the cover can compete for available nesting hens, thus negating the benefits of 1 of the covers. After converting benefits and costs to dollars, we determined the point at which maximum net benefit occurs. We present an equation that can be used to determine the maximum net benefit of a management treatment given the size of the breeding population and the values of costs and benefits. Our examples demonstrate that, on local areas, it is inefficient to spend money for habitat management once maximum net benefit has been attained. If desired production can not be attained efficiently on an area, the manager can invest effort on alternative areas with greater management potential. If recruitment is inadequate to maintain a stable population, managers should manage to increase recruitment before attempting to attract additional breeding pairs. If recruitment more than maintains the breeding population, managers should attempt to attract additional breeding pairs to the area.

Cowardin, L.M.; Shaffer, T.L.; Kraft, K.M.

1995-01-01

317

Restoration Of Carnivore Habitat Connectivity In The Northern Rocky Mountains  

E-print Network

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. "Key linkage areas" were evaluated across the Northern Rocky Mountains of Montana, Idaho and Wyoming. Sixty four highways were considered important as key linkage areas. Twenty of these were considered "high priority" due to the cumulative impacts of having four lanes, high traffic volume, high potential for upgrading, paralleling railroads or critical private lands. Highway planners are encouraged to move towards analyzing "geographic areas" when assessing impacts of highways on wide-ranging carnivores.

Bill Ruediger Endangered; James J. Claar Carnivore

318

Habitat use and home range of the Laysan Teal on Laysan Island, Hawaii  

USGS Publications Warehouse

The 24-hour habitat use and home range of the Laysan Teal (Anas laysanensis), an endemic dabbling duck in Hawaii, was studied using radio telemetry during 1998-2000. Radios were retained for a mean of 40 days (0-123 d; 73 adult birds radio-tagged). Comparisons of daily habitat use were made for birds in the morning, day, evening, and night. Most birds showed strong evidence of selective habitat use. Adults preferred the terrestrial vegetation (88%), and avoided the lake and wetlands during the day. At night, 63% of the birds selected the lake and wetlands. Nocturnal habitat use differed significantly between the non-breeding and breeding seasons, while the lake and wetland habitats were used more frequently during the non-breeding season. Most individuals showed strong site fidelity during the study, but habitat selection varied between individuals. Mean home range size was 9.78 ha (SE ?? 2.6) using the fixed kernel estimator (95% kernel; 15 birds, each with >25 locations). The average minimum convex polygon size was 24 ha (SE ?? 5.6). The mean distance traveled between tracking locations was 178 m (SE ?? 30-5), with travel distances between points ranging up to 1,649 m. Tracking duration varied from 31-121 days per bird (mean tracking duration 75 days).

Reynolds, M.H.

2004-01-01

319

Evaluating the effects of protection on Paracentrotus lividus distribution in two contrasting habitats  

NASA Astrophysics Data System (ADS)

The sea urchin Paracentrotus lividus is common in the Mediterranean in shallow subtidal rocky habitats and in Posidonia oceanica beds. The aim of this study is to investigate whether protection has the same effect on the population structure of P. lividus occurring in rocky reef habitats and in P. oceanica beds. These results are important to generate hypotheses about the influence of human harvesting, predatory pressure and migration processes on P. lividus in the two habitats. Paracentrotus lividus was sampled at seven locations within the Gulf of Alghero (North West Sardinia) where the Capo Caccia-Isola Piana MPA (Marine Protected Area) is sited: 1 location was sited in Zone A, where no harvesting of P. lividus is allowed (NH), 3 locations were sited in Zone B, where harvesting is restricted (RH), and the other 3 were located outside the MPA where no restrictions apply to sea urchin harvesting (UH). For each combination of habitat × location, P. lividus density was assessed in 10 replicates using quadrats of 1 × 1 m and the size of 20 individuals (test diameter without spines) was measured. Finally, the specimens were grouped into size-classes to examine frequency distributions at each location. Sampling was performed at the end of the sea urchin harvesting period (April-May 2006). Analyses of data have highlighted significant variability among locations for both response variables. In both habitats, no differences were found in Paracentrotus lividus abundance among levels of protection (NH vs. RH vs. UH), while a significantly higher size was found in NH rather than in RH and UH locations. Differential direct and indirect effects of protection on P. lividus size is discussed. Also, P. lividus size seemed dependent on the habitat being quite larger in Posidonia oceanica than in the rocky reefs. This finding suggests that settlement and recruitment could be more highly successful events in rocky habitats, and that in P. oceanica meadows large-sized immigrants coming from the rocky habitat contribute to the population structure. The need to define the role of the P. oceanica habitat is also discussed.

Ceccherelli, G.; Pinna, S.; Sechi, N.

2009-01-01

320

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.

321

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

322

Ciliates in chalk-stream habitats congregate in biodiversity hot spots.  

PubMed

Free-living ciliates are a diverse group of microbial eukaryotes that inhabit aquatic environments. They have a vital role within the 'microbial loop', being consumers of microscopic prey such as bacteria, micro-algae, and flagellates, and representing a link between the microscopic and macroscopic components of aquatic food webs. This investigation describes the ciliate communities of four habitats located in the catchment of the River Frome, the major chalk-stream in southern Britain. The ciliate communities were characterised in terms of community assemblage, species abundance and size classes. The ciliate communities investigated proved to be highly diverse, yielding a total of 114 active species. An additional 15 'cryptic' ciliate species were also uncovered. Heterogeneity in the ciliate communities was evident at multiple spatial scales, revealing hot spots of species richness, both within and between habitats. The ciliate communities of habitats with flowing water were composed of smaller ciliates compared to the still-water habitats examined. PMID:20600862

Bradley, Mark W; Esteban, Genoveva F; Finlay, Bland J

2010-09-01

323

Population structure of an endangered species living in contrasted habitats: Parnassia palustris (Saxifragaceae).  

PubMed

In endangered species, it is critical to analyse the level at which populations interact (i.e. dispersal) as well as the levels of inbreeding and local adaptation to set up conservation policies. These parameters were investigated in the endangered species Parnassia palustris living in contrasted habitats. We analysed population structure in 14 populations of northern France for isozymes, cpDNA markers and phenotypic traits related to fitness. Within population genetic diversity and inbreeding coefficients were not correlated to population size. Populations seem not to have undergone severe recent bottleneck. Conversely to pollen migration, seed migration seems limited at a regional scale, which could prevent colonization of new sites even if suitable habitats appear. Finally, the habitat type affects neither within-population genetic diversity nor genetic and phenotypic differentiation among populations. Thus, even if unnoticed local adaptation to habitats exists, it does not influence gene flow between populations. PMID:12030977

Bonnin, Isabelle; Colas, Bruno; Bacles, Cécile; Holl, Anne-Catherine; Hendoux, Frédéric; Destiné, Benoit; Viard, Frédérique

2002-06-01

324

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

325

Habitat: Engineering in a Simulated Audible Ecosystem  

E-print Network

Abstract. This paper introduces a novel approach to generating audio or visual heterogeneity by simulating multi-level habitat formation by ecosystemengineer organisms. Ecosystem engineers generate habitat by modulation of environmental factors, such as erosion or radiation exposure, and provision of substrate. We describe Habitat, a simulation that runs on a two-dimensional grid occupied by an evolving population of stationary agents. The bodies of these agents provide local, differentiated habitat for new agents. Agents evolve using a conventional evolutionary algorithm that acts on their habitat preferences, habitat provision and lifespan, to populate the space and one another. This generates heterogeneous, dynamic structures that have been used in a prototype sonic artwork and simple visualisation.

Alan Dorin

326

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

327

Measuring habitat availability for dispersing animals  

Microsoft Academic Search

Understanding dispersal is central to ecology and evolution. To integrate habitat selection and dispersal it is important\\u000a to compare habitat used for movement to those available in the landscape, i.e. found in an area that an animal could access\\u000a in a given time period. Here, we explore ways of determining available habitat for dispersing individuals, illustrated by\\u000a recent studies on

Vesa Selonen; Ilpo K. Hanski; André Desrochers

2010-01-01

328

75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...  

Federal Register 2010, 2011, 2012, 2013

...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

329

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

330

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

331

Accessible habitat: an improved measure of the effects of habitat loss and roads on wildlife populations  

Microsoft Academic Search

Habitat loss is known to be the main cause of the current global decline in biodiversity, and roads are thought to affect\\u000a the persistence of many species by restricting movement between habitat patches. However, measuring the effects of roads and\\u000a habitat loss separately means that the configuration of habitat relative to roads is not considered. We present a new measure

Felix Eigenbrod; Stephen J. Hecnar; Lenore Fahrig

2008-01-01

332

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.

Science, Lawrence H.

2007-01-01

333

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...

334

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...

335

Optimal floating and queuing strategies: consequences for density dependence and habitat loss.  

PubMed

Field studies of many vertebrates show that some individuals (floaters) do not defend territories even when there is space for them to do so. We show that the evolutionarily stable strategy (ESS) for the threshold territory quality at which floating takes place is that which maximizes the size of the floating population (but not the total population, breeding population, or reproductive output). The ESS is solved separately for two assumptions: whether individuals wait to occupy a single territory or multiple territories and whether queuing rules are strict or if all waiting individuals are equally likely to obtain the next territory. The four combinations of these assumptions all give the same evolutionarily stable population size of both floaters and breeders. At the ESS, only territories with expected lifetime reproductive success (LRS) exceeding 1 should be occupied, which introduces a limit to ideal habitat selection. The behavioral decision to float alters the shape of the density-dependent response, reduces the equilibrium population size, and affects the response of the population to habitat loss. Specifically, the floater: breeder ratio is directly related to average breeding habitat quality, and the floater population size will decrease more than the breeding population size if better than average quality habitat is lost. PMID:18811444

Kokko, H; Sutherland, W J

1998-09-01

336

NOAA HABITAT BLUEPRINT Healthy habitats that sustain resilient and thriving marine  

E-print Network

Habitat Focus Areas to prioritize long-term habitat science and conservation efforts. We will direct our Blueprint provides a forward-looking framework for NOAA to think and act strategically across programs depend. Recognizing the need for more concerted efforts to conserve (protect and restore) habitat, we

337

Portion size  

MedlinePLUS

... lettuce -- four leaves (Romaine lettuce) One medium baked potato -- a computer mouse To control your portion sizes ... harder for you to overeat. Substitute lower-fat varieties of food. Instead of whole-fat cream cheese, ...

338

The Habitat Demonstration Unit Project  

NASA Technical Reports Server (NTRS)

This paper will describe an overview of the NASA-led multi-center Habitat Demonstration Unit (HDU) Project. The HDU project is a technology-pull project that integrates technologies and innovations from numerous NASA centers. This project will be used to investigate and validate surface architectures, operations concepts, and requirements definition. The HDU project will be part of the 2010 Desert Research and Technologies Simulations (DRATS). The purpose of this project is to develop, integrate, test, and evaluate a HDU in the context of the mission architectures and surface operation concepts. This HDU is based on the Constellation Architecture Scenario 12.1 concept of a vertically oriented habitat module. A multi-center approach with be utilized to build, integrate, and test the HDU project through a shared collaborative effort of multiple NASA centers. This project is part of the strategic plan from the ESMD Directorate Integration Office (DIO) and the Lunar Surface Systems Project Office (LSSPO) to test surface elements in a surface analog environment which includes two Lunar Electric Rovers and the HDU during the 2010 analog field test. This paper will describe the overall objectives, its various configurations, strategic plan, and technology integration as it pertains to the 2010 and 2011 field analog tests.

Kennedy, Kriss J.; Gill, Tracy; Tri, Terry; Howe, Scott

2009-01-01

339

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.

340

Trends in space occupation by the encrusting sponge Crambe crambe : variation in shape as a function of size and environment  

Microsoft Academic Search

The relationship between sponge size, habitat and shape was studied in the encrusting sponge Crambe crambe (Schmidt, 1862), which is distributed widely throughout the shallow Mediterranean littoral. Examination of sponge patches in shaded and well-illuminated habitats showed that the degree of peripheral irregularity of the edges of a patch is directly related to patch size. This relationship is valid only

M. A. Becerro; M. J. Uriz; X. Turon

1994-01-01

341

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

342

Habitat use and ecological interactions of an introduced and a native species of Anolis lizard on Grand Cayman, with a review of the outcomes of anole introductions  

Microsoft Academic Search

Since its introduction ten years ago, Anolis sagrei has spread over much of Grand Cayman and is now more common in some habitats than the native anole, A. conspersus. Interspecific differences in body size, perch height, and microclimatic preference may have facilitated the colonization. Nonetheless, competition may be occurring between the species; comparisons with studies of habitat use prior to

Jonathan B. Losos; Jane C. Marks; Thomas W. Schoener

1993-01-01

343

A hierarchical analysis of nesting and foraging habitat for the conservation of the Hispaniolan White-winged crossbill ( Loxia leucoptera megaplaga)  

Microsoft Academic Search

Little is known about habitat use by the endemic Hispaniolan White-winged crossbill (Loxia leucoptera megaplaga), in part because of its small population size and wandering tendencies; before this study only a single nest had been described for the species. From 1996 to 1999 we studied crossbill abundance, and foraging and nesting habitat at three scales (individual tree, local patch, and

Steven C. Latta; Marriah L. Sondreal; Christopher R. Brown

2000-01-01

344

Incorporating fine-scale seascape composition in an assessment of habitat quality for the giant sea anemone Stichodactyla gigantea in a coral reef shore zone  

Microsoft Academic Search

Habitat loss due to land reclamation often occurs in sandy coral reef shore zones. The giant sea anemone Stichodactyla gigantea, which harbors the false clown anemonefish Amphiprion ocellaris, both of which are potentially flagship species, inhabit these places. To assess habitat quality for S. gigantea, we examined correlative associations between the number and the body size of S. gigantea and

Akihisa Hattori; Miyako Kobayashi

2009-01-01

345

Strong habitat preference of a tropical rain forest tree does not imply large differences in population dynamics across habitats  

Microsoft Academic Search

Summary 1 Many tropical forest tree species show habitat preference, commonly revealed by differences in abundance among habitats. Very little is known about differences in individual performance and population dynamics across habitats. 2 We analysed habitat-specific performance and demography of Scaphium borneense , a tropical rain forest tree with strong habitat preference in a 52-ha plot at Lambir Hills, Malay-

TOSHIHIRO YAMADA; PIETER A. ZUIDEMA; AKIRA ITOH; TAKUO YAMAKURA; TATSUHIRO OHKUBO; MAMORU KANZAKI; SYLVESTER TAN; PETER S. ASHTON

2007-01-01

346

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

347

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

348

Environmental adaptation in stomatal size independent of the effects of genome size.  

PubMed

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

349

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

350

Habitat distribution for non-native Amazona viridigenalis within San Diego County using Maxent predictive model  

NASA Astrophysics Data System (ADS)

Human propagated changes to the environment have adversely affected certain species while advantaging other species. Psittacines, or species that fall within the parrot family, have been found to be well adapted to modified environments. Over time, transportation of various parrot species for use in the exotic pet trade has caused accidental releases of individual parrots, resulting in species groups forming and colonizing in new, non-native environments, specifically urban and suburban ones. Amazona viridigenalis, the Red-crowned parrot, is a species that has adapted to living in several regions within the United States including Texas, Florida, and California. This species is endangered within its native range in the lowlands of eastern Mexico, yet has the largest population of any other psittacine species in California. Despite this interesting dichotomy this species remains severely understudied in its new range. Using geographic information systems and Maxent predictive model, this research aims to achieve a greater understanding of the extent of habitat suitable to the Amazona viridigenalis within San Diego County and the habitat variables that enable its establishment success. Presence locations where individuals of the species were using habitat were collected along with 12 important variables that represent Red-crowned parrot habitat elements. These were used in the creation of a predictive habitat model utilizing Maxent machine-learning technique. Three models were created using three different background extents from which the pseudo-absence points were generated. These models were tested for statistical significance and predictive accuracy. It was found that model performance significantly decreased with a decrease in size of model extent. The largest extent was chosen to model habitat using the five variables that were found to be the least correlated, achieved the most gain, and had the most explanatory power for the earlier models. The final model generated depicts highly suitable habitat for A. viridigenalis along the entire coast of San Diego County with pockets of moderately suitable to highly suitable habitat infiltrating into the interior. Some locations in East County were also identified as having moderate habitat suitability. It was found that A. viridigenalis requires habitat with elevations between sea level and 200 m., slopes of zero to 11% grade, and large amounts of non-native vegetated ground cover. More suitable habitat was found at locations with moderate to high population density and in close proximity to roads, suggesting the importance of human-presence in shaping habitat for A. viridigenalis.

Meseck, Kristin April

351

Effects of Habitat Quality and Landscape Structure  

E-print Network

Feb 8, 2005 ... demonstrate how the effects of habitat quality (extra environmental factors) and ... Geographic Information System (GIS); habitat quality; incidence ... 1998), and it has been used in the study of several ...... 5514556 in Proceedings of the Second IEEE International. Conference on Evolutionary Computation.

352

Trends in Methods for Assessing Freshwater Habitats  

Microsoft Academic Search

Habitat assessment is an important form of management for species conservation, mitigation planning, environmental regulation, and impact assessment. As part of an American Fisheries Society and U.S. Fish and Wildlife Service project, we surveyed state, provincial, federal, and private organizations to obtain documentation about methods being used to assess aquatic habitats in the inland waters of North America. We then

Mark B. Bain; Thomas C. Hughes; Kristin K. Arend

1999-01-01

353

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

354

How Habitat Edges Change Species Interactions  

Microsoft Academic Search

Traditionally, ecologists interested in habitat edges have focused on edge-related gradients in patterns of species richness or abiotic variables. Here, however, we take a different perspective, at- tempting to synthesize recent empirical results concerning the effects of habitat edges on population dynamics with contemporary theo- retical developments to outline the ways in which species interactions, and the dynamics of the

William F. Fagan; Robert Stephen Cantrell; Chris Cosner

1999-01-01

355

Community-based habitat restoration program  

Microsoft Academic Search

Summary form only given. As follows: The Restoration Center is working to forge closer ties between NOAA and local constituencies. In FY96, the Restoration Center began a community-based restoration initiative to enable staff to become more directly involved in local habitat restoration activities that benefit NOAA trust resources. To date, this effort provided funds for 20 habitat restoration projects at

C. D. Doley

1999-01-01

356

PRINCIPAL COMPONENT ANALYSIS OF WOODPECKER NESTING HABITAT  

Microsoft Academic Search

Biologists have long been able to associate species of birds in a general way, with their characteristic habitats. Yet, for most species few such studies of a quantitative nature have been published. James (1971) used principal component and discriminant function analyses to ordinate breeding habitats of 46 species of breeding birds in Arkansas on vegetational continua. These kinds of analyses

RICIIAKD N. COIVNER; CUKTIS S. ADKISSON

1977-01-01

357

Schoolyard Habitats[R] Site Planning Guide.  

ERIC Educational Resources Information Center

This document provides guidance for the creation of habitats on school grounds. Science activities, resources, and information on how to apply knowledge to the design, creation, and development of a habitat are presented. Contents include: (1) "Starting the Process"; (2) "Gathering Information: Site Inventory and Analysis"; (3) "Assembling the…

National Wildlife Federation, Reston, VA.

358

Relating Habitat and Climatic Niches in Birds  

E-print Network

Predicting species ’ responses to the combined effects of habitat and climate changes has become a major challenge in ecology and conservation biology. However, the effects of climatic and habitat gradients on species distributions have generally been considered separately. Here, we explore the relationships between the habitat and thermal dimensions of the ecological niche in European common birds. Using data from the French Breeding Bird Survey, a large-scale bird monitoring program, we correlated the habitat and thermal positions and breadths of 74 bird species, controlling for life history traits and phylogeny. We found that cold climate species tend to have niche positions in closed habitats, as expected by the conjunction of the biogeographic history of birds ’ habitats, and their current continent-scale gradients. We also report a positive correlation between thermal and habitat niche breadths, a pattern consistent with macroecological predictions concerning the processes shaping species ’ distributions. Our results suggest that the relationships between the climatic and habitat components of the niche have to be taken into account to understand and predict changes in species’

Jean-yves Barnagaud; Vincent Devictor; Frédéric Jiguet; Morgane Barbet-massin; Isabelle Le Viol; Frédéric Archaux

2011-01-01

359

Habitat Fragmentation, Species Loss, and Biological Control  

Microsoft Academic Search

Fragmentation of habitats in the agricultural landscape is a major threat to biological diversity, which is greatly determined by insects. Isolation of habitat fragments resulted in decreased numbers of species as well as reduced effects of natural enemies. Manually established islands of red clover were colonized by most available herbivore species but few parasitoid species. Thus, herbivores were greatly released

Andreas Kruess; Teja Tscharntke

1994-01-01

360

Estuary Restoration Act Estuary Habitat Restoration Council  

E-print Network

Estuary Restoration Act Estuary Habitat Restoration Council Ranked Proposal Recommendations June 12 estuary restoration efforts and to contribute to the Puget Sound Partnership's Action Agenda recovery goal Restoration for Ecosystem Services and Fish Habitat in Great Bay Estuary, NH The project will restore 10 acres

US Army Corps of Engineers

361

Estuaries and Tidal Marshes. Habitat Pac.  

ERIC Educational Resources Information Center

This educational packet consists of an overview, three lesson plans, student data sheets, and a poster. The overview examines estuaries and tidal or salt marshes by discussing the plants and animals in these habitats, marsh productivity, benefits and management of the habitats, historical aspects, and development and pollution. A glossary and list…

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

362

Habitat Partitioning among Three Species of Ephemerelloidea  

Microsoft Academic Search

Niche volumes according to several physical and water quality parameters are shown for Drunella grandis, Drunella doddsi and Tricorythodes minutus. Generalist strategies have been adopted by D. grandis for physical habitat characteristics and by T. minutus for water quality characteristics. Drunella doddsi, a specialist, has the smallest physical habitat and water quality niche dimensions of the three mayfly species. Even

Robert N. Winget

1993-01-01

363

Habitat Strategies Northwest Power and Conservation Council  

E-print Network

May 11, 2007 ISAB 2007-2 Human Population Impacts on Columbia River Basin Fish and Wildlife June 8 and productivity of species J. McColgan 2000 BLM: Alaska Fire Service Bitterroot National Forest Montana drought-basin effects #12;Impact on Habitat Strategies Uncertainty ·physical and biological ·economic and social Habitat

364

Static Atmospheres in a Rotating Space Habitat.  

ERIC Educational Resources Information Center

Discusses O'Neill's proposal for the colonization of space as it offers new problems in pure physics. Addresses specifically the distribution of the atmosphere in O'Neill's habitat and whether there will be enough air at the axis of rotation to allow human-powered flight, with particular reference to the habitat's "artificial gravity." (CS)

McKinley, John M.

1980-01-01

365

FINAL DRAFT FRAP Habitat Conservation and Restoration Program  

E-print Network

FINAL DRAFT FRAP Habitat Conservation and Restoration Program Review of Results SUMMARY VERSION,7FRAP Habitat Program · Review of Results · Summary Version Final Draft · December 15, 1997 1 FRAP Habitat Conservation and Restoration Program Review of Results

366

50 CFR 660.75 - Essential Fish Habitat (EFH).  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Essential Fish Habitat (EFH). 660.75 Section 660.75...Coast Groundfish Fisheries § 660.75 Essential Fish Habitat (EFH). Essential fish habitat (EFH) is defined as those waters...

2012-10-01

367

50 CFR 660.75 - Essential Fish Habitat (EFH).  

...2014-10-01 2014-10-01 false Essential Fish Habitat (EFH). 660.75 Section 660.75...Coast Groundfish Fisheries § 660.75 Essential Fish Habitat (EFH). Essential fish habitat (EFH) is defined as those waters...

2014-10-01

368

50 CFR 660.395 - Essential Fish Habitat (EFH)  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Essential Fish Habitat (EFH) 660.395 Section 660.395...Groundfish Fisheries § 660.395 Essential Fish Habitat (EFH) Essential fish habitat (EFH) is defined as those waters...

2010-10-01

369

50 CFR 660.75 - Essential Fish Habitat (EFH).  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Essential Fish Habitat (EFH). 660.75 Section 660.75...Coast Groundfish Fisheries § 660.75 Essential Fish Habitat (EFH). Essential fish habitat (EFH) is defined as those waters...

2013-10-01

370

50 CFR 660.75 - Essential Fish Habitat (EFH).  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Essential Fish Habitat (EFH). 660.75 Section 660.75...Coast Groundfish Fisheries § 660.75 Essential Fish Habitat (EFH). Essential fish habitat (EFH) is defined as those waters...

2011-10-01

371

Assessing patterns of fish demographics and habitat in stream networks  

EPA Science Inventory

Effective habitat restoration planning requires correctly anticipating demographic responses to altered habitats. New applications of Passive Integrated Transponder (PIT) tag technology to fish-habitat research have provided critical insights into fish movement, growth, and surv...

372

Accomplishments of the Alaska Region's Habitat Conservation Division  

E-print Network

Fisheries Science Center; NOAA Fisheries Office of Habitat Conservation; NOAA General Counsel; and NOAAAccomplishments of the Alaska Region's Habitat Conservation Division in Fiscal Year 2006 This report provides highlights of Habitat Conservation Division (HCD) activities in support

373

50 CFR 226.208 - Critical habitat for green turtle.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Critical habitat for green turtle. 226.208 Section 226.208 Wildlife and Fisheries...DESIGNATED CRITICAL HABITAT § 226.208 Critical habitat for green turtle. (a) Culebra Island, Puerto...

2010-10-01

374

50 CFR 226.209 - Critical habitat for hawksbill turtle.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Critical habitat for hawksbill turtle. 226.209 Section 226...COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.209 Critical habitat for hawksbill turtle. (a) Mona and...

2011-10-01

375

50 CFR 226.209 - Critical habitat for hawksbill turtle.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Critical habitat for hawksbill turtle. 226.209 Section 226...COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.209 Critical habitat for hawksbill turtle. (a) Mona and...

2012-10-01

376

50 CFR 226.207 - Critical habitat for leatherback turtle.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Critical habitat for leatherback turtle. 226.207 Section...COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.207 Critical habitat for leatherback turtle. Leatherback Sea...

2011-10-01

377

50 CFR 226.209 - Critical habitat for hawksbill turtle.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Critical habitat for hawksbill turtle. 226.209 Section 226...COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.209 Critical habitat for hawksbill turtle. (a) Mona and...

2013-10-01

378

50 CFR 226.209 - Critical habitat for hawksbill turtle.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Critical habitat for hawksbill turtle. 226.209 Section 226...COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.209 Critical habitat for hawksbill turtle. (a) Mona and...

2010-10-01

379

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

EPA Science Inventory

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

380

Breeding habitat expansion in the Grey heron ( Ardea cinerea)  

NASA Astrophysics Data System (ADS)

Predicting the response of natural populations to habitat loss and the ecological consequences to communities is one of the great challenges of ecology. Here, we report long-term (30 years) results from an ecological survey illustrating a change of breeding habits in the Grey heron, Ardea cinerea. Comparative data on brood size show that Grey herons adopting a new breeding behaviour produce more nestlings than other individuals in the modified area. Interestingly, this recent behavioural change may result in indirect effects on the community structure by negatively affecting the breeding population of the Purple heron Ardea purpurea.

Thomas, Frédéric; Hafner, Heinz

2000-03-01

381

Increasing density leads to generalization in both coarse-grained habitat selection and fine-grained resource selection in a large mammal.  

PubMed

Density is a fundamental driver of many ecological processes including habitat selection. Theory on density-dependent habitat selection predicts that animals should be distributed relative to profitability of habitat, resulting in reduced specialization in selection (i.e. generalization) as density increases and competition intensifies. Despite mounting empirical support for density-dependent habitat selection using isodars to describe coarse-grained (interhabitat) animal movements, we know little of how density affects fine-grained resource selection of animals within habitats [e.g. using resource selection functions (RSFs)]. Using isodars and RSFs, we tested whether density simultaneously modified habitat selection and within-habitat resource selection in a rapidly growing population of feral horses (Equus ferus caballus Linnaeus; Sable Island, Nova Scotia, Canada; 42% increase in population size from 2008 to 2012). Among three heterogeneous habitat zones on Sable Island describing population clusters distributed along a west-east resource gradient (west-central-east), isodars revealed that horses used available habitat in a density-dependent manner. Intercepts and slopes of isodars demonstrated a pattern of habitat selection that first favoured the west, which generalized to include central and east habitats with increasing population size consistent with our understanding of habitat quality on Sable Island. Resource selection functions revealed that horses selected for vegetation associations similarly at two scales of extent (total island and within-habitat zone). When densities were locally low, horses were able to select for sites of the most productive forage (grasslands) relative to those of poorer quality. However, as local carrying capacity was approached, selection for the best of available forage types weakened while selection for lower-quality vegetation increased (and eventually exceeded that of grasslands). Isodars can effectively describe coarse-grained habitat selection in large mammals. Our study also shows that the main predictions of density-dependent habitat selection are highly relevant to our interpretation of RSFs in space and time. At low but not necessarily high population size, density will be a leading indicator of habitat quality. Fitness maximization from specialist vs. generalist strategies of habitat and resource selection may well be apparent at multiple spatial extents and grains of resolution. PMID:23931034

van Beest, Floris M; Uzal, Antonio; Vander Wal, Eric; Laforge, Michel P; Contasti, Adrienne L; Colville, David; McLoughlin, Philip D

2014-01-01

382

Assessing habitat quality for a migratory songbird wintering in natural and agricultural habitats.  

PubMed

As tropical forests are cleared, a greater proportion of migratory songbirds are forced to winter in agricultural and disturbed habitats, which, if poorer in quality than natural forests, could contribute to population declines. We compared demographic indicators of habitat quality for a focal species, the American Redstart (Setophaga ruticilla), wintering in Jamaican citrus orchards and shade coffee plantations with those in four natural habitats: mangrove, coastal scrub, coastal palm, and dry limestone forests. Demographic measures of habitat quality included density, age and sex ratio, apparent survival, and changes in body mass. Measures of habitat quality for redstarts in citrus and coffee habitats were generally intermediate between the highest (mangrove) and lowest (dry limestone) measurements from natural habitats. The decline in mean body mass over the winter period was a strong predictor of annual survival rate among habitats, and we suggest that measures of body condition coupled with survival data provide the best measures of habitat quality for nonbreeding songbirds. Density, which is far easier to estimate, was correlated with these more labor-intensive measures, particularly in the late winter when food is likely most limiting. Thus, local density may be useful as an approximation of habitat quality for wintering migrant warblers. Our findings bolster those of previous studies based on bird abundance that suggest arboreal agricultural habitats in the tropics can be useful for the conservation of generalist, insectivorous birds, including many migratory passerines such as redstarts. PMID:17002761

Johnson, Matthew D; Sherry, Thomas W; Holmes, Richard T; Marra, Peter P

2006-10-01

383

Does body size affect a bird's sensitivity to patch size and landscape structure?  

USGS Publications Warehouse

Larger birds are generally more strongly affected by habitat loss and fragmentation than are smaller ones because they require more resources and thus larger habitat patches. Consequently, conservation actions often favor the creation or protection of larger over smaller patches. However, in grassland systems the boundaries between a patch and the surrounding landscape, and thus the perceived size of a patch, can be indistinct. We investigated whether eight grassland bird species with different body sizes perceived variation in patch size and landscape structure in a consistent manner. Data were collected from surveys conducted in 44 patches of northern tallgrass prairie during 1998-2001. The response to patch size was very similar among species regardless of body size (density was little affected by patch size), except in the Greater Prairie-Chicken (Tympanuchus cupido), which showed a threshold effect and was not found in patches smaller than 140 ha. In landscapes containing 0%-30% woody vegetation, smaller species responded more negatively to increases in the percentage of woody vegetation than larger species, but above an apparent threshold of 30%, larger species were not detected. Further analyses revealed that the observed variation in responses to patch size and landscape structure among species was not solely due to body size per se, but to other differences among species. These results indicate that a stringent application of concepts requiring larger habitat patches for larger species appears to limit the number of grassland habitats that can be protected and may not always be the most effective conservation strategy. ?? The Cooper Ornithological Society 2006.

Winter, M.; Johnson, D.H.; Shaffer, J.A.

2006-01-01

384

Classification of immature mosquito species according to characteristics of the larval habitat in the subtropical province of Chaco, Argentina.  

PubMed

To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidity, colour, odour and movement of the larval habitat's water were also collected. From the cluster analysis, three groups of species associated by their degree of habitat similarity were obtained and are listed below. Group 1 consisted of Aedes aegypti. Group 2 consisted of Culex imitator, Culex davisi, Wyeomyia muehlensi and Toxorhynchites haemorrhoidalis separatus. Within group 3, two subgroups are distinguished: A (Psorophora ferox, Psorophora cyanescens, Psorophora varinervis, Psorophora confinnis, Psorophora cingulata, Ochlerotatus hastatus-oligopistus, Ochlerotatus serratus, Ochlerotatus scapularis, Culex intrincatus, Culex quinquefasciatus, Culex pilosus, Ochlerotatus albifasciatus, Culex bidens) and B (Culex maxi, Culex eduardoi, Culex chidesteri, Uranotaenia lowii, Uranotaenia pulcherrima, Anopheles neomaculipalpus, Anopheles triannulatus, Anopheles albitarsis, Uranotaenia apicalis, Mansonia humeralis and Aedeomyia squamipennis). Principal component analysis indicates that the size of the larval habitats and the presence of aquatic vegetation are the main characteristics that explain the variation among different species. In contrast, water permanence is second in importance. Water temperature, pH and the type of larval habitat are less important in explaining the clustering of species. PMID:21739026

Stein, Marina; Ludueña-Almeida, Francisco; Willener, Juana Alicia; Almirón, Walter Ricardo

2011-06-01

385

Developing a Habitat for Long Duration, Deep Space Missions  

NASA Technical Reports Server (NTRS)

One possible next leap in human space exploration is a mission to a near Earth asteroid (NEA). In order to achieve such an ambitious goal, a space habitat will need to be designed to accommodate a crew of four for the 380-day round trip. The Human Spaceflight Architecture Team (HAT) developed a conceptual design for such a habitat. The team identified activities that would be performed inside a long-duration, deep space habitat, and the capabilities needed to support such a mission. A list of seven functional activities/capabilities was developed: individual and group crew care, spacecraft and mission operations, subsystem equipment, logistics and resupply, and contingency operations. The volume for each activity was determined using NASA STD-3001 and the companion Human Integration Design Handbook (HIDH). Although, the sum of these volumes produced an over-sized spacecraft, the team evaluated activity frequency and duration to identify functions that could share a common volume without conflict, reducing the total volume by 24%. After adding 10% for growth, the resulting functional pressurized volume was calculated to be 268 m3 distributed over the functions. The work was validated through comparison with the International Space Station (ISS), Bigelow Aerospace s proposed habitat module, and NASA s Trans-Hab concepts. In the end, the team developed an internal layout that (a) minimized the transit time between related crew stations, (b) accommodated expected levels of activity at each station, (c) isolated stations when necessary for health, safety, performance, and privacy, and (d) provided a safe, efficient, and comfortable work and living environment.

Rucker, Michelle A.; Thompson, Shelby

2011-01-01

386

Developing a Habitat for Long Duration, Deep Space Missions  

NASA Technical Reports Server (NTRS)

One possible next leap in human space exploration for the National Aeronautics and Space Administration (NASA) is a mission to a near Earth asteroid (NEA). In order to achieve such an ambitious goal, a space habitat will need to accommodate a crew of four for the 380-day round trip. The Human Spaceflight Architecture Team (HAT) developed a conceptual design for such a habitat. The team identified activities that would be performed inside a long-duration, deep space habitat, and the capabilities needed to support such a mission. A list of seven functional activities/capabilities was developed: individual and group crew care, spacecraft and mission operations, subsystem equipment, logistics and resupply, and contingency operations. The volume for each activity was determined using NASA STD-3001 and the companion Human Integration Design Handbook (HIDH). Although, the sum of these volumes produced an over-sized spacecraft, the team evaluated activity frequency and duration to identify functions that could share a common volume without conflict, reducing the total volume by 24%. After adding 10% for growth, the resulting functional pressurized volume was calculated to be a minimum of 268 cu m (9,464 cu ft) distributed over the functions. The work was validated through comparison to Mir, Skylab, the International Space Station (ISS), Bigelow Aerospace s proposed habitat module, and NASA s Trans-Hab concept. Using HIDH guidelines, the team developed an internal layout that (a) minimized the transit time between related crew stations, (b) accommodated expected levels of activity at each station, (c) isolated stations when necessary for health, safety, performance, and privacy, and (d) provided a safe, efficient, and comfortable work and living environment.

Rucker, Michelle A.; Thompson, Shelby

2012-01-01

387

A Tool for the Automated Design and Evaluation of Habitat Interior Layouts  

NASA Technical Reports Server (NTRS)

The objective of space habitat design is to minimize mass and system size while providing adequate space for all necessary equipment and a functional layout that supports crew health and productivity. Unfortunately, development and evaluation of interior layouts is often ignored during conceptual design because of the subjectivity and long times required using current evaluation methods (e.g., human-in-the-loop mockup tests and in-depth CAD evaluations). Early, more objective assessment could prevent expensive design changes that may increase vehicle mass and compromise functionality. This paper describes a new interior design evaluation method to enable early, structured consideration of habitat interior layouts. This interior layout evaluation method features a comprehensive list of quantifiable habitat layout evaluation criteria, automatic methods to measure these criteria from a geometry model, and application of systems engineering tools and numerical methods to construct a multi-objective value function measuring the overall habitat layout performance. In addition to a detailed description of this method, a C++/OpenGL software tool which has been developed to implement this method is also discussed. This tool leverages geometry modeling coupled with collision detection techniques to identify favorable layouts subject to multiple constraints and objectives (e.g., minimize mass, maximize contiguous habitable volume, maximize task performance, and minimize crew safety risks). Finally, a few habitat layout evaluation examples are described to demonstrate the effectiveness of this method and tool to influence habitat design.

Simon, Matthew A.; Wilhite, Alan W.

2013-01-01

388

Landscape responses of bats to habitat fragmentation in Atlantic forest of paraguay  

USGS Publications Warehouse

Understanding effects of habitat loss and fragmentation on populations or communities is critical to effective conservation and restoration. This is particularly important for bats because they provide vital services to ecosystems via pollination and seed dispersal, especially in tropical and subtropical habitats. Based on more than 1,000 h of survey during a 15-month period, we quantified species abundances and community structure of phyllostomid bats at 14 sites in a 3,000-km2 region of eastern Paraguay. Abundance was highest for Artibeus lituratus in deforested landscapes and for Chrotopterus auritus in forested habitats. In contrast, Artibeus fimbriatus, Carollia perspicillata, Glossophaga soricina, Platyrrhinus lineatus, Pygoderma bilabiatum, and Sturnira lilium attained highest abundance in moderately fragmented forest landscapes. Forest cover, patch size, and patch density frequently were associated with abundance of species. At the community level, species richness was highest in partly deforested landscapes, whereas evenness was greatest in forested habitat. In general, the highest diversity of bats occurred in landscapes comprising moderately fragmented forest habitat. This underscores the importance of remnant habitat patches to conservation strategies.

Gorresen, P.M.; Willig, M.R.

2004-01-01

389

Habitat-Specific Morphological Variation among Threespine Sticklebacks (Gasterosteus aculeatus) within a Drainage Basin  

PubMed Central

Habitat-specific morphological variation, often corresponding to resource specialization, is well documented in freshwater fishes. In this study we used landmark based morphometric analyses to investigate morphological variation among threespine sticklebacks (Gasterosteus aculeatus L.) from four interconnected habitat types within a single lowland drainage basin in eastern England. These included the upper and lower reaches of the river, the estuary, a connected ditch network and a coastal salt marsh. We found significant habitat-specific differences in morphology, with three axes of variation describing differences in orbit diameter, body depth, caudal peduncle shape and pectoral fin positioning as well as variation in relative dorsal and pelvic spine size. Interestingly, the ditch system, an artificial and heavily managed habitat, is populated by sticklebacks with a characteristic morphology, suggesting that human management of habitats can in some circumstances lead to morphological variation among the animals that inhabit them. We discuss the mechanisms that conceivably underlie the observed morphological variation and the further work necessary to identify them. Finally, we consider the implications of habitat-specific body shape variation for the behavioural ecology of this ecologically generalist species. PMID:21698269

Webster, Mike M.; Atton, Nicola; Hart, Paul J. B.; Ward, Ashley J. W.

2011-01-01

390

Annual variation in the distribution, abundance, and habitat response of the palila (Loxioides bailleui)  

USGS Publications Warehouse

We studied the distribution, population size, and habitat response of the Palila (Loxioides bailleui) during the 1980-1984 nonbreeding seasons to infer factors that limit the population and to develop management strategies. Distribution was fairly constant from year to year. Palila were confined to the subalpine woodland on Mauna Kea on the island of Hawaii, occurred between 2,000 and 2,850 m elevation, and reached highest densities on the southwests lopes. The population showed large annual fluctuations from 6,400 birds in 1981 to 2,000 in 1984. The width of woodland was the most important variable in determining habitat response. Palila were more common in areas with greater crown cover, taller trees, and a higher proportion of native plants in the understory. Annual variation in Palila density within a habitat reflected variation in levels of their staple food, mamane pods. The main limiting factors of the population appeared to be the availability of good habitat and levels of their staple food. Palila had strongly depressed densities in the Pohakuloa flats area. This low density could not be explained by gross habitat features or food levels. Site tenacity, thermal stress, disturbance, and disease were hypothesized explanations. Our study indicated that the most effective management strategies would be the removal of feral ungulates and certain noxious plants from Palila habitat and the extension of the woodland zone to areas now intensively grazed

Scott, J.M.; Mountainspring, S.; van Riper, Charles, III; Kepler, C.B.; Jacobi, J.D.; Burr, T.A.; Giffen, J.G.

1984-01-01

391

HOME RANGE AND HABITAT USE OF NORTHERN SPOTTED OWLS ON THE OLYMPIC PENINSULA, WASHINGTON  

Microsoft Academic Search

We studied movements and habitat selection of 20 adult northern Spotted Owls (Strix oc- cidentalis caurina) on the Olympic Peninsula, Washington in 1987-89. Median annual home range size of individual owls was 1147 ha based on the 75% isopleth of the Fixed Kernel (FK), 2406 ha based on the 95% FK, and 2290 ha based on the 100% Minimum Convex

CHERON FERLAND; ELIZABETH M. GLENN

392

Evaluating the consequences of habitat fragmentation: a case study in the common forest herb Trillium camschatcense  

Microsoft Academic Search

The effects of habitat fragmentation on remnant plant populations have rarely been studied extensively using a single species. We have attempted to quantify the effects of forest fragmentation (primarily that of population size) on populations of Trillium camschatcense, a representative spring herb in the Tokachi plain of Hokkaido, Japan. In this region, intensive agricultural development over the past 100 years has

Hiroshi Tomimatsu; Masashi Ohara

2006-01-01

393

Recruitment Habitats and Nursery Grounds of the American Lobster Homarus Americanus: A Demographic Bottleneck?  

Microsoft Academic Search

We have identified benthic recruitment habitats and nursery grounds of the American lobster Homarus americanus Milne Edwards in the coastal Gulf of Maine, USA, by systematically censusing subtidal sediment, cobble, and ledge substrata. We distinguish lobsters between settlement size (5 mm carapace length (CL) to ca 40 mm CL as the 'early benthic phase' (EBP) because they are ecologically and

Richard Wahle; Robert Steneck

1991-01-01

394

Interactions among stream fishes: predator-induced habitat shifts and larval survival  

Microsoft Academic Search

Adult largemouth bass alter habitat use by, and abundances of, other fishes in small streams. Experimental manipulations of bass in natural stream pools (Brier Creek, Oklahoma) showed that responses of other fishes to adult bass were highly dependent on prey size, and that both direct and indirect effects of adult bass influence the distribution and abundance of other stream fishes.

Bret C. Harvey

1991-01-01

395

Scale-Dependent Effects of Habitat Fragmentation on Hawthorn Pollination, Frugivory, and Seed Predation  

Microsoft Academic Search

Habitat fragmentation is a major cause of functional disruption in plant-animal interactions. The net effect on plant regeneration is, however, controversial because a given landscape change can simultaneously hamper mutualism and attenuate antagonism. Furthermore, fragmentation effects may emerge at different spatial scales, depending on the size of the foraging range of the different interacting animals. We studied pollination by insects,

DANIEL GARCIA; NATACHA P. CHACOFF

2006-01-01

396

Settlement and nursery habitats for demersal fishes on the continental shelf  

E-print Network

and nursery areas. Between June 1996 and July 1997, settlement and nursery habitats of age-0 (early juvenile species collected, 33 included age-0 juveniles, and 25 included near-settlement size individuals. The two). Abstract.­Although juvenile fish are studied extensively in estuarine and nearshore environments

397

Selection of Pupation Habitats by Oriental Fruit Fly Larvae in the Laboratory  

Microsoft Academic Search

We performed a series of laboratory experiments to determine the effects of shade, soil moisture, and soil compaction on the selection of pupation habitats by wandering late-instar Oriental fruit flies, Bactrocera dorsalis (Hendel). Larvae showed a strong preference toward pupating in shaded rather than brightly lit areas, in moist rather than dry soil, and in soil with larger particle sizes.

Andrei V. Alyokhin; Christian Mille; Russell H. Messing; Jian J. Duan

2001-01-01

398

Fish-habitat modeling for gap analysis to conserve the endangered Topeka shiner (Notropis topeka)  

E-print Network

Fish-habitat modeling for gap analysis to conserve the endangered Topeka shiner (Notropis topeka of the endangered Topeka shiner (Notropis topeka) using stream condition variables (stream size, groundwater pour coder des sections de vallées quant la probabilité de la présence du méné de Topeka (Notropis

399

Evaluating the Effect of Green Infrastructure Stormwater Best Management Practices on New England Stream Habitat  

EPA Science Inventory

The U.S. EPA is evaluating the effectiveness of green infrastructure (GI) stormwater best management practices (BMPs) on stream habitat at the small watershed (< HUC12) scale in New England. Predictive models for thermal regime and substrate characteristics (substrate size, % em...

400

Mexican Spotted Owl Home Range and Habitat Use in Pine-Oak Forest: Implications for Forest Management  

Microsoft Academic Search

To better understand the habitat relationships of the Mexican spotted owl (Strix occidentalis lucida), and how such relationships might influence forest management, we studied home-range and habitat use of radio-marked owls in ponderosa pine (Pinus ponderosa)-Gambel oak (Quercus gambeli~) forest. Annual home-range size (95% adaptive-kernel estimate) averaged 895 ha * 70 (SE) for 12 individuals and 997 ha + 186

Joseph L. Ganey; William M. Block; Jeffrey S. Jenness; Randolph A. Wilson

1999-01-01

401

Influence of Patch Size and Shape on Occupancy by Shrubland Birds  

Microsoft Academic Search

Populations of many shrubland bird species are declining in the eastern United States. Efforts to restore shrubland and early-successional forest may help to ameliorate these declines. However, uncertainty remains about how the size and shape of habitat patches and the surrounding habitat matrix affect patch occupancy by shrubland passerines. Our objectives were to determine if shrubland birds avoid small or

Corey S. Shake; Christopher E. Moorman; Jason D. Riddle; Michael R. Burchell

2012-01-01

402

Patch Size and Landscape Effects on Density and Nesting Success of Grassland Birds  

Microsoft Academic Search

Current management recommendations for grassland birds in North America emphasize providing large patches of grassland habitat within landscapes that have few forest or shrubland areas. These Bird Conservation Areas are being proposed under the assumption that large patches of habitat in treeless landscapes will maintain viable populations of grassland birds. This assumption requires that patch size and landscape features affect

MAIKEN WINTER; DOUGLAS H. JOHNSON; JILL A. SHAFFER; THERESE M. DONOVAN; W. DANIEL SVEDARSKY; Rodewald

2006-01-01

403

When species' ranges meet: assessing differences in habitat selection between sympatric large carnivores.  

PubMed

Differentiation in habitat selection among sympatric species may depend on niche partitioning, species interactions, selection mechanisms and scales considered. In a mountainous area in Sweden, we explored hierarchical habitat selection in Global Positioning System-collared individuals of two sympatric large carnivore species; an obligate predator, the Eurasian lynx (Lynx lynx), and a generalist predator and scavenger, the wolverine (Gulo gulo). Although the species' fundamental niches differ widely, their ranges overlap in this area where they share a prey base and main cause of mortality. Both lynx and wolverines selected for steep and rugged terrain in mountainous birch forest and in heaths independent of scale and available habitats. However, the selection of lynx for their preferred habitats was stronger when they were forming home ranges and they selected the same habitats within their home ranges independent of home range composition. Wolverines displayed a greater variability when selecting home ranges and habitat selection also varied with home range composition. Both species selected for habitats that promote survival through limited encounters with humans, but which also are rich in prey, and selection for these habitats was accordingly stronger in winter when human activity was high and prey density was low. We suggest that the observed differences between the species result primarily from different foraging strategies, but may also depend on differences in ranging and resting behaviour, home range size, and relative density of each species. Our results support the prediction that sympatric carnivores with otherwise diverging niches can select for the same resources when sharing main sources of food and mortality. PMID:23242426

Rauset, Geir Rune; Mattisson, Jenny; Andrén, Henrik; Chapron, Guillaume; Persson, Jens

2013-07-01

404

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

NASA Astrophysics Data System (ADS)

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

Suvorov, Petr; Svobodová, Jana; Albrecht, Tomáš

2014-08-01

405

Patterns of space and habitat use by northern bobwhites in South Florida, USA  

USGS Publications Warehouse

The manner by which animals use space and select resources can have important management consequences. We studied patterns of habitat selection by northern bobwhites (Colinus virginianus) on Babcock-Webb Wildlife Management Area, Charlotte County, Florida and evaluated factors influencing the sizes of their home ranges. A total of 1,245 radio-tagged bobwhites were monitored for 19,467 radio days during 2002-2007. The mean (?? 1 SE) annual home range size, estimated using the Kernel density method, was 88. 43 (?? 6. 16) ha and did not differ between genders. Winter home ranges of bobwhites (69. 27 ?? 4. 92 ha) were generally larger than summer home ranges (53. 90 ?? 4. 93 ha). Annual and winter home ranges were smaller for bobwhites whose ranges contained food plots compared to those that did not; however, the presence of food plots did not influence summer home ranges. We used distance-based methods to investigate habitat selection by bobwhites at two scales: selection of home ranges within the study site (second-order selection) and selection of habitats within home ranges (third-order selection). Across both scales, bobwhites generally preferred food plots and dry prairie habitat and avoided wet prairies and roads. This pattern was generally consistent between genders and across years. Our data indicate that management practices aimed at increasing and maintaining a matrix of food plots and dry prairie habitat would provide the most favorable environment for bobwhites. ?? 2010 Springer-Verlag.

Singh, A.; Hines, T.C.; Hostetler, J.A.; Percival, H.F.; Oli, M.K.

2011-01-01

406

Habitat complexity and sex-dependent predation of mosquito larvae in containers  

PubMed Central

Studies in aquatic systems have shown that habitat complexity may provide refuge or reduce the number of encounters prey have with actively searching predators. For ambush predators, habitat complexity may enhance or have no effect on predation rates because it conceals predators, reduces prey detection by predators, or visually impairs both predators and prey. We investigated the effects of habitat complexity and predation by the ambush predators Toxorhynchites rutilus and Corethrella appendiculata on their mosquito prey Aedes albopictus and Ochlerotatus triseriatus in container analogs of treeholes. As in other ambush predator-prey systems, habitat complexity did not alter the effects of T. rutilus or C. appendiculata whose presence decreased prey survivorship, shortened development time, and increased adult size compared to treatments where predators were absent. Faster growth and larger size were due to predator-mediated release from competition among surviving prey. Male and female prey survivorship were similar in the absence of predators, however when predators were present, survivorship of both prey species was skewed in favor of males. We conclude that habitat complexity is relatively unimportant in shaping predator-prey interactions in this treehole community, where predation risk differs between prey sexes. PMID:16041612

Griswold, Marcus W.; Lounibos, L. Philip

2012-01-01

407

Home range and habitat use by Great Horned Owls (Bubo virginianus) in Southern California  

USGS Publications Warehouse

Great Horned Owls (Bubo virginianus) are a common, widespread species that can be found in a variety of habitats across most of North America, but little is known about their space and habitat requirements. Using radiotelemetry, location data were collected on nine male and five female Great Horned Owls to determine home range and habitat use in southern California. Owls were tracked between January 1997 and September 1998 for periods ranging from 5-17 mo. Seven owls were also followed during 13 all-night observation periods. The mean 95% adaptive kernel home-range size for females was 180 ha (range = 88-282, SE = 36) and that for males was 425 ha (range = 147-1115 ha, SE = 105). Core areas estimated by the 50% adaptive kernel averaged 27 ha (range = 7-44, SE = 7) for females and 61 ha (range = 15-187, SE = 18) for males. Owls were located in areas with varying degrees of human disturbance ranging from almost entirely urban to native oak (Quercus agrifolia) woodland. Oak/sycamore (Quercus agrifolia/Platanus racemosa) woodland and ruderal grassland (Bromus spp., Avena spp., and various other non-native invasives), were used more often than expected based on availability, but we found no correlation between home-range size and any single habitat type or habitat groups. ?? 2005 The Raptor Research Foundation, Inc.

Bennett, J.R.; Bloom, P.H.

2005-01-01

408

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

SciTech Connect

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 young pines even though large tracks of bottomland hardwood were available. Only 9% of foraging occurred in bottomland hardwoods.

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

2000-03-13

409

Modeling habitat dynamics accounting for possible misclassification  

USGS Publications Warehouse

Land cover data are widely used in ecology as land cover change is a major component of changes affecting ecological systems. Landscape change estimates are characterized by classification errors. Researchers have used error matrices to adjust estimates of areal extent, but estimation of land cover change is more difficult and more challenging, with error in classification being confused with change. We modeled land cover dynamics for a discrete set of habitat states. The approach accounts for state uncertainty to produce unbiased estimates of habitat transition probabilities using ground information to inform error rates. We consider the case when true and observed habitat states are available for the same geographic unit (pixel) and when true and observed states are obtained at one level of resolution, but transition probabilities estimated at a different level of resolution (aggregations of pixels). Simulation results showed a strong bias when estimating transition probabilities if misclassification was not accounted for. Scaling-up does not necessarily decrease the bias and can even increase it. Analyses of land cover data in the Southeast region of the USA showed that land change patterns appeared distorted if misclassification was not accounted for: rate of habitat turnover was artificially increased and habitat composition appeared more homogeneous. Not properly accounting for land cover misclassification can produce misleading inferences about habitat state and dynamics and also misleading predictions about species distributions based on habitat. Our models that explicitly account for state uncertainty should be useful in obtaining more accurate inferences about change from data that include errors.

Veran, Sophie; Kleiner, Kevin J.; Choquet, Remi; Collazo, Jaime A.; Nichols, James D.

2012-01-01

410

Generalisation of physical habitat-discharge relationships  

NASA Astrophysics Data System (ADS)

Physical habitat is increasingly used worldwide as a measure of river ecosystem health when assessing changes to river flows, such as those caused by abstraction. The major drawback with this approach is that defining precisely the relationships between physical habitat and flow for a given river reach requires considerable data collection and analysis. Consequently, widely used models such as the Physical Habitat Simulation (PHABSIM) system are expensive to apply. There is, thus, a demand for rapid methods for defining habitat-discharge relationships from simple field measurements. This paper reports the analysis of data from 63 sites in the UK where PHABSIM has been applied. The results demonstrate that there are strong relationships between single measurements of channel form and river hydraulics and the habitat available for target species. The results can form the basis of a method to estimate sensitivity of physical habitat to flow change by visiting a site at only one flow. Furthermore, the uncertainty in estimates reduces as more information is collected. This allows the user to select the level of investment in data collection appropriate for the desired confidence in the estimates. The method is demonstrated using habitat indicators for different life stages of Atlantic salmon, brown trout, roach and dace.

Booker, D. J.; Acreman, M. C.

2007-01-01

411

Does Learning or Instinct Shape Habitat Selection?  

PubMed Central

Habitat selection is an important behavioural process widely studied for its population-level effects. Models of habitat selection are, however, often fit without a mechanistic consideration. Here, we investigated whether patterns in habitat selection result from instinct or learning for a population of grizzly bears (Ursus arctos) in Alberta, Canada. We found that habitat selection and relatedness were positively correlated in female bears during the fall season, with a trend in the spring, but not during any season for males. This suggests that habitat selection is a learned behaviour because males do not participate in parental care: a genetically predetermined behaviour (instinct) would have resulted in habitat selection and relatedness correlations for both sexes. Geographic distance and home range overlap among animals did not alter correlations indicating that dispersal and spatial autocorrelation had little effect on the observed trends. These results suggest that habitat selection in grizzly bears are partly learned from their mothers, which could have implications for the translocation of wildlife to novel environments. PMID:23341983

Nielsen, Scott E.; Shafer, Aaron B. A.; Boyce, Mark S.; Stenhouse, Gordon B.

2013-01-01

412

Combining Data to Assess of the Habitat Suitability of Patches of Streambed  

NASA Astrophysics Data System (ADS)

Many of the aquatic animals that live in cave streams are threatened, endangered, or endemic. Management plans needed to conserve the aquatic ecosystems within which these animals live must be based on an understanding of the food webs, life histories, and habitat suitability. However, for many of these ecosystems, there is very little information about the food webs, life histories, or habitat suitability. If information is available, that information is frequently incomplete. One aspect of habitat suitability is the stability of the streambed sediment. Sediment that can be scoured over a wide range of hydrologic conditions is not suitable habitat as scour events disrupt the streambed sediment resulting in dispersal or possibly death of the animals; whereas, sediment that cannot be scoured would be suitable habitat. Assessing sediment stability requires hydrologic and sedimentologic data and assessing habitat suitability requires population consensus data. Rarely are the three disparate sets of data collected. Our objective was to develop a method that can be used to assess streambed stability using disparate data sets. At locations along the cave streams for which we have conducted population consensuses and particle-size distribution data, we used the flow competence method to assess streambed stability. At each location, the depth of water that would result in scour of the sediment was calculated (a constant) and was compared to the measured or calculated depth of the water (a function of time). In absence of measured depth of water data, we used a numerical model of unsteady state flow along the two main stream channels to calculate the depth of water at each consensus location in each ecosystem. Habitat suitability was evaluated by comparing the presence or absence of animals at each consensus location with our understanding of the stability of the streambed at the same location. With a calibrated numerical model and water depth and sedimentologic data, this method can be used to pinpoint patches of streambed that are likely to serve as habitat (not subjected to scour) and those patches that are not likely to serve as habitat (subjected to scour). As collection of population consensus data is time consuming this will allow researchers to focus their preliminary consensus counts at locations where scour is not predicted to occur (likely locations of suitable habitat). By combining data sets that were from collected by disparate groups of researchers, we have developed a method that can be used to assess scour and habitat suitability.

Wicks, C. M.; Aley, T.; Ashley, D.; Noltie, D.

2011-12-01

413

Evaluation of two methods of estimating larval habitat productivity in western Kenya highlands  

PubMed Central

Background Malaria vector intervention and control programs require reliable and accurate information about vector abundance and their seasonal distribution. The availability of reliable information on the spatial and temporal productivity of larval vector habitats can improve targeting of larval control interventions and our understanding of local malaria transmission and epidemics. The main objective of this study was to evaluate two methods of estimating larval habitat productivity in the western Kenyan highlands, the aerial sampler and the emergence trap. Methods The study was conducted during the dry and rainy seasons in 2008, 2009 and 2010. Aerial samplers and emergence traps were set up for sixty days in each season in three habitat types: drainage ditches, natural swamps, and abandoned goldmines. Aerial samplers and emergence traps were set up in eleven places in each habitat type. The success of each in estimating habitat productivity was assessed according to method, habitat type, and season. The effect of other factors including algae cover, grass cover, habitat depth and width, and habitat water volume on species productivity was analysed using stepwise logistic regression Results Habitat productivity estimates obtained by the two sampling methods differed significantly for all species except for An. implexus. For for An. gambiae s.l. and An. funestus, aerial samplers performed better, 21.5 and 14.6 folds, than emergence trap respectively, while the emergence trap was shown to be more efficient for culicine species. Seasonality had a significant influence on the productivity of all species monitored. Dry season was most productive season. Overall, drainage ditches had significantly higher productivity in all seasons compared to other habitat types. Algae cover, debris, chlorophyll-a, and habitat depth and size had significant influence with respect to species. Conclusion These findings suggest that the aerial sampler is the better of the two methods for estimating the productivity of An. gambiae s.l. and An. funestus in the western Kenya highlands and possibly other malaria endemic parts of Africa. This method has proven to be a useful tool for monitoring malaria vector populations and for control program design, and provides useful means for determining the most suitable sites for targeted interventions. PMID:21682875

2011-01-01

414

Lake trout spawning habitat in the Great Lakes u a review of current knowledge  

USGS Publications Warehouse

We review existing information on lake trout spawning habitat, which might indicate whether habitat is now a limiting factor in lake trout reproductive success. Lake trout spawning habitat quality is defined by the presence or absence of olfactory cues for homing, reef location with respect to the shoreline, water depth, proximity to nursery areas, reef size, contour, substrate size and shape, depth of interstitial spaces, water temperature at spawning time, water quality in interstitial spaces, and the presence of egg and fry predators. Data on factors which attracted native spawners to spawning reefs are lacking, due to the absence of historic data on egg deposition. No direct evidence of egg deposition has been collected from sites deeper than 18 m. Interstitial space and, therefore, substrate size and shape, appear to be critical for both site selection by adults and protection of eggs and fry. Water quality is clearly important for egg incubation, but the critical parameters which define water quality have not yet been well determined in the field. Exposure to wave energy, dictated in part by reef location, may maintain high water quality but may also damage or dislodge eggs. The importance of olfactory cues, water temperature, and proximity to nursery habitat to spawning trout is unclear. Limited data suggest that egg and fry predators, particularly exotic species, may critically affect fry production and survival. Although availability of physical spawning habitat is probably not limiting lake trout reproduction, changes in water quality and species composition may negatively affect early life stages. This review of habitat factors that affect early life stages of lake trout suggests several priorities for research and management.

Marsden, J. Ellen; Casselman, John M.; Edsall, Thomas A.; Elliott, Robert F.; Fitzsimons, John D.; Horns, William H.; Manny, Bruce A.; McAughey, Scott C.; Sly, Peter G.; Swanson, Bruce L.

1995-01-01

415

Habitat selection in a clonal plant.  

PubMed

Rhizomatous growth may permit the nonrandom placement of ramets into different environments, but whether clonal plants are able to use this means to exercise adaptive habitat choice is not known. Western ragweed (Ambrosia psilostachya) plants are shown to preferentially colonize nonsaline soil over saline soil patches, and clones with the strongest preference for nonsaline soil are those least able to grow when restricted to saline conditions. In clonal plant species, nonrandom associations of genotypes with specific environments may thus reflect habitat selection by plants as well as selective mortality imposed by different habitat patches. PMID:3983647

Salzman, A G

1985-05-01

416

Assessment and Management of Dead-Wood Habitat  

USGS Publications Warehouse

Introduction The Bureau of Land Management (BLM) is in the process of revising its resource management plans for six districts in western and southern Oregon as the result of the settlement of a lawsuit brought by the American Forest Resource Council. A range of management alternatives is being considered and evaluated including at least one that will minimize reserves on O&C lands. In order to develop the bases for evaluating management alternatives, the agency needs to derive a reasonable range of objectives for key issues and resources. Dead-wood habitat for wildlife has been identified as a key resource for which decision-making tools and techniques need to be refined and clarified. Under the Northwest Forest Plan, reserves were to play an important role in providing habitat for species associated with dead wood (U.S. Department of Agriculture Forest Service and U.S. Department of the Interior Bureau of Land Management, 1994). Thus, the BLM needs to: 1) address the question of how dead wood will be provided if reserves are not included as a management strategy in the revised Resource Management Plan, and 2) be able to evaluate the effects of alternative land management approaches. Dead wood has become an increasingly important conservation issue in managed forests, as awareness of its function in providing wildlife habitat and in basic ecological processes has dramatically increased over the last several decades (Laudenslayer et al., 2002). A major concern of forest managers is providing dead wood habitat for terrestrial wildlife. Wildlife in Pacific Northwest forests have evolved with disturbances that create large amounts of dead wood; so, it is not surprising that many species are closely associated with standing (snags) or down, dead wood. In general, the occurrence or abundance of one-quarter to one-third of forest-dwelling vertebrate wildlife species, is strongly associated with availability of suitable dead-wood habitat (Bunnell et al., 1999; Rose et al., 2001). In Oregon and Washington, approximately 150 species of wildlife are reported to use dead wood in forests (O'Neil et al., 2001). Forty-seven sensitive and special-status species are associated with dead wood (Appendix A). These are key species for management consideration because concern over small or declining populations is often related to loss of suitable dead-wood habitat (Marshall et al., 1996). Primary excavators (woodpeckers) also are often the focus of dead-wood management, because they perform keystone functions in forest ecosystems by creating cavities for secondary cavity-nesters (Martin and Eadie, 1999; Aubry and Raley, 2002). A diverse guild of secondary cavity-users (including swallows, bluebirds, several species of ducks and owls, ash-throated flycatcher, flying squirrel, bats, and many other species) is unable to excavate dead wood, and therefore relies on cavities created by woodpeckers for nesting sites. Suitable nest cavities are essential for reproduction, and their availability limits population size (Newton, 1994). Thus, populations of secondary cavity-nesters are tightly linked to the habitat requirements of primary excavators. Although managers often focus on decaying wood as habitat for wildlife, the integral role dead wood plays in ecological processes is an equally important consideration for management. Rose et al. (2001) provide a thorough review of the ecological functions of dead wood in Pacific Northwest forests, briefly summarized here. Decaying wood functions in: soil development and productivity, nutrient cycling, nitrogen fixation, and carbon storage. From ridge tops, to headwater streams, to estuaries and coastal marine ecosystems, decaying wood is fundamental to diverse terrestrial and aquatic food webs. Wildlife species that use dead wood for cover or feeding are linked to these ecosystem processes through a broad array of functional roles, including facilitation of decay and trophic interactions with other org

Hagar, Joan

2007-01-01

417

Joint Effects of Habitat Heterogeneity and Species’ Life-History Traits on Population Dynamics in Spatially Structured Landscapes  

PubMed Central

Both habitat heterogeneity and species’ life-history traits play important roles in driving population dynamics, yet there is little scientific consensus around the combined effect of these two factors on populations in complex landscapes. Using a spatially explicit agent-based model, we explored how interactions between habitat spatial structure (defined here as the scale of spatial autocorrelation in habitat quality) and species life-history strategies (defined here by species environmental tolerance and movement capacity) affect population dynamics in spatially heterogeneous landscapes. We compared the responses of four hypothetical species with different life-history traits to four landscape scenarios differing in the scale of spatial autocorrelation in habitat quality. The results showed that the population size of all hypothetical species exhibited a substantial increase as the scale of spatial autocorrelation in habitat quality increased, yet the pattern of population increase was shaped by species’ movement capacity. The increasing scale of spatial autocorrelation in habitat quality promoted the resource share of individuals, but had little effect on the mean mortality rate of individuals. Species’ movement capacity also determined the proportion of individuals in high-quality cells as well as the proportion of individuals experiencing competition in response to increased spatial autocorrelation in habitat quality. Positive correlations between the resource share of individuals and the proportion of individuals experiencing competition indicate that large-scale spatial autocorrelation in habitat quality may mask the density-dependent effect on populations through increasing the resource share of individuals, especially for species with low mobility. These findings suggest that low-mobility species may be more sensitive to habitat spatial heterogeneity in spatially structured landscapes. In addition, localized movement in combination with spatial autocorrelation may increase the population size, despite increased density effects. PMID:25232739

Ye, Xinping; Skidmore, Andrew K.; Wang, Tiejun

2014-01-01

418

Carnivore home-range size, metabolic needs and ecology  

Microsoft Academic Search

Relationships between home-range size, metabolic needs of the animals occupying the homerange, and ecology are examined across species in the order Carnivora. Home-range size increases with metabolic needs, irrespective of taxonomic affinity. When the effects of metabolic needs are removed, among ecological variables (including activity pattern, habitat, diet and zonation) only diet shows a significant influence on home-range size. Carnivores

John L. Gittleman; Paul H. Harvey

1982-01-01

419

Breeding canvasbacks: a test of a habitat model  

USGS Publications Warehouse

Schroeder (1984) proposed a habitat suitability model for breeding canvasbacks (Aythya valisineria) based on the size, water regime, and emergent vegetation of wetlands. We evaluated the model with data from surveys of canvasbacks on 2265 wetlands in North Dakota, South Dakota, and Minnesota. The model proved inadequate as a predictor of canvasback pair density; the correlation between values produced by the model and canvasback pair densities was r = 0.0023 (P = 0.911). There were, however, suggestions of (1) higher canvasback density and frequency of occurrence on wetlands with more open interiors, and (2) a relation between canvasback density and wetland size that varied according to wetland permanence. We recommend that the model be improved by testing these relations, and possibly by incorporating determinants of water quality or pondweed (Potamogeton spp.) occurrence.

Johnson, D.H.; Hammond, M.C.; McDonald, T.L.; Nustad, C.L.

1989-01-01

420

Can settlement in natal-like habitat explain maladaptive habitat selection?  

PubMed Central

The study of habitat selection has long been influenced by the ideal free model, which maintains that young adults settle in habitat according to its inherent quality and the density of conspecifics within it. The model has gained support in recent years from the finding that conspecifics produce cues inadvertently that help prebreeders locate good habitat. Yet abundant evidence shows that animals often fail to occupy habitats that ecologists have identified as those of highest quality, leading to the conclusion that young animals settle on breeding spaces by means not widely understood. Here, we report that a phenomenon virtually unknown in nature, natal habitat preference induction (NHPI), is a strong predictor of territory settlement in both male and female common loons (Gavia immer). NHPI causes young animals to settle on natal-like breeding spaces, but not necessarily those that maximize reproductive success. If widespread, NHPI might explain apparently maladaptive habitat settlement. PMID:23804619

Piper, Walter H.; Palmer, Michael W.; Banfield, Nathan; Meyer, Michael W.

2013-01-01

421

Fine scale movements and habitat use of black brant during the flightless Wing Molt in Arctic Alaska  

USGS Publications Warehouse

Thousands of Black Brant (Branta bernicla nigricans) migrate annually to the Teshekpuk Lake Special Area (TLSA), Alaska, to undergo the flightless wing molt on tundra lakes and wetlands. GPS transmitters were attached to Brant over two summers (2007?????"2008) to examine patterns of movement and habitat use of molting Brant, including variation by habitat type, year and body mass. Molting Brant were located an average of 31 ??1 m (SE) from shore and this distance did not vary across any of the explanatory variables. Brant moved an average of 123 ??3 m hr-1 while flightless. Movement rates varied by year, averaging 22 ??12 m hr-1 faster in 2008, and across habitat types, averaging 22 ??13 m hr-1 faster in inland versus coastal and estuarine habitats. Two kernel home ranges were estimated: entire home range, which encompassed the complete 95% probability contour, and shoreline home range, which included only shoreline areas used by molting Brant. Entire home range (x bar = 15.1 ??2.2 km2) was negatively correlated with body mass, suggesting that heavier individuals have more body reserves to contribute to feather growth and thereby require less food and smaller home ranges. Conversely, shoreline home range (x bar = 4.3 ??0.6 km2) did not vary by body mass, but rather by habitat type, being larger in estuarine habitats. The complex shorelines and numerous deltaic islands of estuarine habitats offer more shoreline per area than either coastal or inland habitats. Brant appear to have limited ability to adjust their home range size or forage further from shore in response to variable food resources across years or habitats, instead altering their movement rate. Given this apparent lack of behavioral flexibility, Brant may be sensitive to development-related disturbances or habitat losses at molt sites in the TLSA.

Lewis, T.L.; Flint, P.L.; Derksen, D.V.; Schmutz, J.A.

2011-01-01

422

Habitat triage for exploited fishes: Can we identify essential “Essential Fish Habitat?”  

NASA Astrophysics Data System (ADS)

There is little doubt that estuarine habitat is important for some exploited fish species, at some times, and in some places. However, it is also clear that we do not have enough resources to conserve or restore all estuarine habitat. Consequently, a simple, quantitative and transparent approach to prioritizing estuarine habitat management is required. Here, we present a general framework for identifying critical habitats of exploited fishes. Our approach requires three basic steps: (1) develop stage-structured models and identify sensitive life history stages; (2) determine what habitats, if any, are important to these stages; and (3) identify sites in which high densities of critical life stages occur in important habitat. We will illustrate the utility of this approach using red drum, Sciaenops ocellatus. Results of a simulation-based sensitivity analysis of a stage-structured matrix model show that most of the variability in population growth rate ( ?) of red drum is explained by larval and juvenile survival rates. Thus, this approach indicates that larval/juvenile red drum habitat should be given higher priority for conservation and/or restoration than habitats used by other life history stages. To illustrate the potential importance of juvenile habitat to red drum, we modeled the growth of a hypothetical red drum population using different population matrices as manifestations of varying habitat conditions. These numerical experiments revealed that restoration of both marsh and seagrass habitats would yield a ca. 24% increase in post-settlement survival and would result in a ca. 2% increase in ?—an increase sufficient to stem a long-term population decline. Our results illustrate that protection of fish habitat depends not only on protecting sites where fish occur but also on protecting the ecological processes that allow populations to expand. Quantitative and synthetic analyses of ecological data are a first step in this direction.

Levin, Phillip S.; Stunz, Gregory W.

2005-07-01

423

Using Satellite Imagery to Assess Large-Scale Habitat Characteristics of Adirondack Park, New York, USA  

NASA Astrophysics Data System (ADS)

Satellite imagery is a useful tool for large-scale habitat analysis; however, its limitations need to be tested. We tested these limitations by varying the methods of a habitat evaluation for white-tailed deer ( Odocoileus virginianus) in the Adirondack Park, New York, USA, utilizing harvest data to create and validate the assessment models. We used two classified images, one with a large minimum mapping unit but high accuracy and one with no minimum mapping unit but slightly lower accuracy, to test the sensitivity of the evaluation to these differences. We tested the utility of two methods of assessment, habitat suitability index modeling, and pattern recognition modeling. We varied the scale at which the models were applied by using five separate sizes of analysis windows. Results showed that the presence of a large minimum mapping unit eliminates important details of the habitat. Window size is relatively unimportant if the data are averaged to a large resolution (i.e., township), but if the data are used at the smaller resolution, then the window size is an important consideration. In the Adirondacks, the proportion of hardwood and softwood in an area is most important to the spatial dynamics of deer populations. The low occurrence of open area in all parts of the park either limits the effect of this cover type on the population or limits our ability to detect the effect. The arrangement and interspersion of cover types were not significant to deer populations.

McClain, Bobbi J.; Porter, William F.

2000-11-01

424

Habitat Characteristics that Made Delta Landscapes Unique  

E-print Network

Report) #12;"Restore large areas of interconnected habitats" - Delta Vision Strategic Plan "Develop" - Second Draft Delta Plan "The expected outcome is restored large, interconnected patches of tidal ecological, hydrologic, and geomorphic processes project goals #12;FLUVIAL PROCESSES TIDAL PROCESSES

425

Columbia River Contaminants and Habitat Study  

USGS Multimedia Gallery

USGS scientists strategize near the Rooster Rock boat launch en route to Skamania Landing to collect fish for the Columbia River Contaminants and Habitat Study. People pictured from the left: Glen Holmberg, Leticia Torres, Conrad Frost, Elena Nilsen....

426

The Habitat for Lactoris fernandeziana (Lactoridaceae)  

NSDL National Science Digital Library

View of ""Tres Picos"" (Three Peaks) from Villagra on Robinson Crusoe Island, which is in the Juan Fernandez archipelago off the coast of Chile. The closer vegetation represents the habitat for Lactoris fernandeziana (Lactoridaceae).

Gregory J. Anderson (University of Connecticut; Department of Ecology and Evolutionary Biology ADR; POSTAL)

2004-03-09

427

PROGRAM TO ASSIST IN TRACKING CRITICAL HABITAT  

EPA Science Inventory

PATCH is a spatially explicit, individual-based, life history simulator designed to project populations of territorial terrestrial vertebrate species through time. PATCH is ideal for investigations involving wildlife species that are mobile habitat specialists. PATCH's data req...

428

Lunar and Planetary Bases, Habitats, and Colonies  

NASA Technical Reports Server (NTRS)

This special bibliography includes the design and construction of lunar and Mars bases, habitats, and settlements; construction materials and equipment; life support systems; base operations and logistics; thermal management and power systems; and robotic systems.

2004-01-01

429

Geography Action! Habitats: Home Sweet Home  

NSDL National Science Digital Library

National Geographic's Geography Action! is an "annual conservation and awareness program designed to educate and excite people about our natural, cultural, and historic treasures." This year the theme is Habitats: Home Sweet Home. Just as there are an amazing variety of habitats on the planet, so does this Web site have an amazing variety of features. In addition to habitat-specific lesson plans (ranging from grades K-12), visitors will find fantastic collections of National Geographic photos; interesting Web links; and several interactive multimedia adventures, such as piloting a mini-sub through a virtual kelp forest or taking an animated trek through the Arctic. The site also provides numerous ideas for exploring and protecting your own habitat.

430

Carnivore habitat ecology: integrating theory and application  

E-print Network

10 Carnivore habitat ecology: integrating theory and application Michael S. Mitchell and Mark viability. Few vertebrate groups better epitomize such populations than carnivores. Yet efforts to quantify what makes places habitable for carnivores are strongly compromised when poorly considered

Mitchell, Mike

431

75 FR 71325 - Wildlife Habitat Incentive Program  

Federal Register 2010, 2011, 2012, 2013

...Wildlife means non-domesticated birds, fishes, reptiles, amphibians, invertebrates, and mammals.'' Section 636.4 Program...Wildlife means non-domesticated birds, fishes, reptiles, amphibians, invertebrates, and mammals. Wildlife habitat means...

2010-11-23

432

HABITAT FRAGMENTATION CUMULATIVE IMPACT SCREENING ANALYSIS  

EPA Science Inventory

Region 6 EPA uses a GIS screening system to evaluate specific areas and construction projects within our five states. The methodology evaluates disruptions to landscape through evaluation of wildlife habitat quantity and quality, endangered species, surface and groundwater vulne...

433

HABITAT AT FISHER RESTING SITES IN THE KLAMATH PROVINCE  

Microsoft Academic Search

The resting habitat of fisher (Martes pennanti) on the Hoopa Valley Indian Reservation (Hoopa) was compared to resting habitat on the Shasta-Trinity National Forest (Shasta-Trinity) in northern California to identify critical habitat characteristics. Comparison of fisher abundance indices at the two study areas suggested fisher were more numerous at Hoopa, which may represent differing habitat condition at the two study

J. Scott Yaeger

434

Habitat Acquisition Strategies for Grassland Birds in an Urbanizing Landscape  

E-print Network

Habitat Acquisition Strategies for Grassland Birds in an Urbanizing Landscape Stephanie A. Snyder Ã?+Business Media, LLC 2007 Abstract Habitat protection for grassland birds is an important component of open space if necessary) as much grassland habitat as possible for a given budget. Because a viable habitat for grassland

Miller, James R.

435

Benthic macrofauna habitat associations in Willapa Bay, Washington, USA  

Microsoft Academic Search

Estuary-wide benthic macrofauna habitat associations in Willapa Bay, Washington, United States, were determined for 4 habitats (eelgrass [Zostera marina], Atlantic cordgrass [Spartina alterniflora], mud shrimp [Upogebia pugettensis], ghost shrimp [Neotrypaea californiensis]) in 1996 and 7 habitats (eelgrass, Atlantic cordgrass, mud shrimp, ghost shrimp, oyster [Crassostrea gigas], bare mud\\/sand, subtidal) in 1998. Most benthic macrofaunal species inhabited multiple habitats; however, 2

Steven P. Ferraro; Faith A. Cole

2007-01-01

436

BLACK BEAR HABITAT USE AT PRIEST LAKE, IDAHO  

Microsoft Academic Search

We studied black bear (Ursus americanus) habitat use patterns in northern Idaho from June 1980 to November 1981. Habitat availability was estimated with a random-dot technique and habitat use was determined from 676 radiolocations of 9 adult bears (5 female, 4 male). Black bears preferred selectively logged areas during spring, summer, and fall; clearcuts were avoided during all seasons. Habitat

D. D. YOUNG; J. J. BEECHAM

437

The effect of natal experience on habitat preferences  

Microsoft Academic Search

Several important problems in ecology, evolution and conservation biology are affected by habitat selection in dispersing animals. Experience in the natal habitat has long been considered a potential source of variation in the habitat preferences displayed when dispersers select a post-dispersal habitat. However, the taxonomic breadth of this phenomenon is underappreciated, in part because partially overlapping, taxon-specific definitions in the

Jeremy M. Davis; Judy A. Stamps

2004-01-01

438

Research Article Multiscale Habitat Selection by Burrowing Owls in Black-  

E-print Network

Research Article Multiscale Habitat Selection by Burrowing Owls in Black- Tailed Prairie Dog by habitat quality. To this end, we measured spatial patterns of burrowing owl breeding habitat selection burrow-, site-, colony-, and landscape-scale habitat parameters between burrowing owl nest burrows (n

Conway, Courtney J.

439

Someplace like home: Experience, habitat selection and conservation biology  

Microsoft Academic Search

Recent insights from habitat selection theory may help conservation managers encourage released animals to settle in appropriate habitats. By all measures, success rates for captive–release and translocation programs are low, and have shown few signs of improvement in recent years. We consider situations in which free-living dispersers prefer new habitats that contain stimuli comparable to those in their natal habitat,

Judy A. Stamps; Ronald R. Swaisgood

2007-01-01

440

HABITAT QUALITY: A BRIEF REVIEW FOR WILDLIFE BIOLOGISTS  

Microsoft Academic Search

Understanding habitat quality for wildlife is extre mely important for biologists, but few papers have explored the pros and cons of how to measure i t. In this review, I clarify terminology and distinguish habitat quality from related terms, dif ferentiate habitat quality from animals' and wildli fe managers' perspectives, and describe different ways of measuring habitat quality in the

MATTHEW D. JOHNSON

441

Habitat fragmentation and reproductive success: a structural equation modelling approach  

E-print Network

Habitat fragmentation and reproductive success: a structural equation modelling approach Eric Le on the effects of habitat fragmentation, whereby habitat is lost and the spatial configuration of remaining habitat patches is altered, on individual breeding per- formance. However, we still lack consensus of how

Helle, Samuli

442

L'habitat participatif : Une solution pour le logement  

E-print Network

Affaire 91AVE12004 Mars 2013 L'habitat participatif : Une solution pour le logement abordable L'habitat participatif : une solution pour le logement abordable? Mars 2013 Date Version-Saône Habitat, du Village Vertical, de Haute-Savoie Habitat et d'Habicoop Mars 2013 V3 Relecture par Noémie

Paris-Sud XI, Université de

443

NEKTON-HABITAT ASSOCIATIONS IN YAQUINA BAY, OREGON  

EPA Science Inventory

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

444

Space habitats. [prognosis for space colonization  

NASA Technical Reports Server (NTRS)

Differences between space industrialization and space colonization are outlined along with the physiological, psychological, and esthetic needs of the inhabitants of a space habitat. The detrimental effects of zero gravity on human physiology are reviewed, and the necessity of providing artificial gravity, an acceptable atmosphere, and comfortable relative humidity and temperature in a space habitat is discussed. Consideration is also given to social organization and governance, supply of food and water, and design criteria for space colonies.

Johnson, R. D.

1978-01-01

445

Vegetational designs for insect-habitat management  

NASA Astrophysics Data System (ADS)

Insect habitats in anthropocentric ecosystems consist of crop plants or forest trees and the coexisting non-crop vegetation. The manipulation of the spatial and temporal arrangement of these plant communities can trigger direct or indirect effects on insect pest populations and their associated natural enemy complexes. In this article habitat management is viewed as a technique to design plant associations that support populations of natural enemies or that exert deterrent effects on herbivorous insects.

Altieri, Miguel A.

1983-01-01

446

Habitat split leads to biodiversity decline  

NSDL National Science Digital Library

Amphibians such as frogs are at risk, especially those that have to travel from their homes in forest habitats to aquatic areas to breed and back; and with this added risk, the diversity, or variety, of species declines, according to a new report. Traveling to the water to breed, then returning to the forest is called habitat split, and researchers say that it is usually caused by human activity.

American Association for the Advancement of Science (AAAS;)

2007-12-13

447

Lunar/Mars Surface Habitat Mockups Project  

NASA Technical Reports Server (NTRS)

Surface habitats play a centric role with respect to integration of the crew operations and supporting surface systems for external operations on the moon and Mars. Up to now the only planetary surface habitat NASA has ever developed is the 2-person, 3-day duration Lunar Module from the 1960 s-era Apollo Program. Today s National Vision for Space Exploration pushes far beyond the safety, performance and operational requirements of the Lunar Module, and NASA needs to develop a basis for making habitat design decisions Experience has shown that using mockups very early in a project s life cycle is extremely beneficial, providing data that influences requirements for human design, volumetrics, functionality, systems hardware and operations. Evaluating and comparing a variety of habitat configurations will provide NASA with a cost-effective basis for trades to support lunar and Martian habitat design selection. This paper describes the NASA project that recently has been created to undertake the development and evaluation of a series of planetary surface habitat mockups. This project is in direct response to the Advanced Space Platforms and Systems (ASPS) Element Program s request for novel systems approaches for robust and reconfigurable habitation systems.

Tri, Terry O.; Daues, Katherine R.

2005-01-01

448

Effects of forest fragmentation on the winter body condition and population parameters of an habitat generalist, the wood mouse Apodemus sylvaticus: a test of hypotheses  

NASA Astrophysics Data System (ADS)

Three main causal hypotheses have been proposed to explain the inverse relationships between habitat patch size and density of generalist mouse species in fragmented habitats: 1) enhanced habitat conditions as habitat patch size decreases; 2) inhibited emigration of excess individuals in small and isolated habitat patches; and 3) reduced territoriality in small patches because they are occupied temporarily by nonreproductive individuals. From the mechanism underlying each hypothesis, we derived predictions on the effects of fragment size on the body condition of individuals (measured both as absolute body size and as body mass relative to body size) and some demographic parameters of mouse populations related to reproductive output (sex-ratio and proportions of sexually active and recently-born individuals), and we tested such predictions with data from wood mice Apodemus sylvaticus wintering in three Spanish forest archipelagos in which the inverse relationship between forest patch size and mouse abundance had been previously proven. No differences in average body size or in average body mass relative to body size were detected among fragments. Mouse populations wintering in small fragments showed more male-biased sex-ratios, a larger proportion of sexually active adults and fewer juveniles as compared to mouse populations wintering in large fragments nearby. Results clearly rejected the third hypothesis and did not support the second one. It thus seemed that habitat conditions for mice improved as forest fragment size decreased, although the expected positive effects on individuals could have been prevented by relaxed territoriality and increased food resource depletion by denser mouse populations. Bearing in mind the negative effects of dense wood mice populations on the distribution, abundance and population dynamics of forest species, this apparent enhancement of habitat conditions for mice in small forest fragments could have far-reaching consequences for the long-term persistence of such fragments.

Díaz, Mario; Santos, Tomás; Tellería, JoséLuis

1999-02-01

449

Developing landscape-scaled habitat selection functions for forest wildlife from Landsat data: Judging black bear habitat quality in Louisiana  

Microsoft Academic Search

Understanding habitat needs of animal populations is critical for their effective management. In recent years, technological advances have increased the range of methods available to examine habitat selection patterns. However, available habitat data are often either limited to small geographic areas or are of coarse resolution, resulting in a gap in data to model habitat selection at landscape scales. I

Robert Owen Wagner

2003-01-01

450

Habitat Suitability Index Models: Plains Sharp-Tailed Grouse  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the plains sharp-tailed grouse (Tympanuchus phasianellus jamesi). 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.

1987-01-01

451

Habitat Suitability Index Models: Red-Spotted Newt  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the red-spotted newt (Notophthalmus viridescens viridescens). 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

452

Habitat Suitability Index Models: Black-Tailed Prairie Dog  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the black-tailed prairie dog (Cynomus ludovicianus). 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.

Clippinger, Norman W.

1989-01-01

453

Habitat Suitability Index Models: Northern Pintail (Gulf Coast Wintering)  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a model for evaluating wintering habitat quality for northern pintail (Anas acuta) along the Gulf of Mexico coast. The model is scaled to produce an index between 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 provided.

Howard, Rebecca J.; Kantrud, Harold A.

1986-01-01

454

Habitat Suitability Index Models: Diamondback Terrapin (Nesting) - Atlantic Coast  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the diamondback terrapin (Malaclemys terrapin). 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.

Palmer, William M.; Cordes, Carroll L.

1988-01-01

455

Habitat Suitability Index Models: Black Bear, Upper Great Lakes Region  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the black bear (Ursus americanus). 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.

Rogers, Lynn L.; Allen, Arthur W.

1987-01-01

456

Age-0 Lost River sucker and shortnose sucker nearshore habitat use in Upper Klamath Lake, Oregon: A patch occupancy approach  

USGS Publications Warehouse

We examined habitat use by age-0 Lost River suckers Deltistes luxatus and shortnose suckers Chasmistes brevirostris over six substrate classes and in vegetated and nonvegetated areas of Upper Klamath Lake, Oregon. We used a patch occupancy approach to model the effect of physical habitat and water quality conditions on habitat use. Our models accounted for potential inconsistencies in detection probability among sites and sampling occasions as a result of differences in fishing gear types and techniques, habitat characteristics, and age-0 fish size and abundance. Detection probability was greatest during mid- to late summer, when water temperatures were highest and age-0 suckers were the largest. The proportion of sites used by age-0 suckers was inversely related to depth (range = 0.4-3.0 m), particularly during late summer. Age-0 suckers were more likely to use habitats containing small substrate (64 mm) and habitats with vegetation than those without vegetation. Relatively narrow ranges in dissolved oxygen, temperature, and pH prevented us from detecting effects of these water quality features on age-0 sucker nearshore habitat use.

Burdick, S.M.; Hendrixson, H.A.; VanderKooi, S.P.

2008-01-01

457

Variables influencing the presence of subyearling fall Chinook salmon in shoreline habitats of the Hanford Reach, Columbia River  

USGS Publications Warehouse

Little information currently exists on habitat use by subyearling fall Chinook salmon Oncorhynchus tshawytscha rearing in large, main-stem habitats. We collected habitat use information on subyearlings in the Hanford Reach of the Columbia River during May 1994 and April-May 1995 using point abundance electrofishing. We analyzed measures of physical habitat using logistic regression to predict fish presence and absence in shoreline habitats. The difference between water temperature at the point of sampling and in the main river channel was the most important variable for predicting the presence and absence of subyearlings. Mean water velocities of 45 cm/s or less and habitats with low lateral bank slopes were also associated with a greater likelihood of subyearling presence. Intermediate-sized gravel and cobble substrates were significant predictors of fish presence, but small (256-mm) substrates were not. Our rearing model was accurate at predicting fish presence and absence using jackknifing (80% correct) and classification of observations from an independent data set (76% correct). The habitat requirements of fall Chinook salmon in the Hanford Reach are similar to those reported for juvenile Chinook salmon in smaller systems but are met in functionally different ways in a large river.

Tiffan, K.F.; Clark, L.O.; Garland, R.D.; Rondorf, D.W.

2006-01-01

458

How Well Can We Predict Salmonid Spawning Habitat with LiDAR?  

NASA Astrophysics Data System (ADS)

Suitable salmonid spawning habitat is, to a great extent, determined by physical, landscape driven characteristics such as channel morphology and grain size. Identifying reaches with high-quality spawning habitat is essential to restoration efforts in areas where salmonid species are endangered or threatened. While both predictions of suitable habitat and observations of utilized habitat are common in the literature, they are rarely combined. Here we exploit a unique combination of high-resolution LiDAR data and seven years of 387 individually surveyed Coho and Steelhead redds in Scott Creek, a 77 km2 un-glaciated coastal California drainage in the Santa Cruz Mountains, to both make and test predictions of spawning habitat. Using a threshold channel assumption, we predict grain size throughout Scott Creek via a shear stress model that incorporates channel width, instead of height, using Manning's equation (Snyder et al., 2013). Slope and drainage area are computed from a LiDAR-derived DEM, and channel width is calculated via hydraulic modeling. Our results for median grain size predictions closely match median grain sizes (D50) measured in the field, with the majority of sites having predicted D50's within a factor of two of the observed values, especially for reaches with D50 > 0.02m. This success suggests that the threshold model used to predict grain size is appropriate for un-glaciated alluvial channel systems. However, it appears that grain size alone is not a strong predictor of salmon spawning. Reaches with a high (>0.1m) average predicted D50 do have lower redd densities, as expected based on spawning gravel sizes in the literature. However, reaches with lower (<0.1m) predicted D50 have a wide range of redd densities, suggesting that reach-average grain size alone cannot explain spawning site selection in the finer-grained reaches of Scott Creek. We turn to analysis of bedform morphology in order to explain the variation in redd density in the low-slope, finer-grained reaches of Lower Scott Creek. Because spawning is strongly correlated with riffle locations, we use a LiDAR-derived longitudinal profile to predict where riffle habitat is located within the watershed. To accomplish this, we use previous studies that constrain pool-riffle habitat to slopes <1.5%, then use wavelet analysis of the longitudinal profile within these pool-riffle reaches to investigate the spacing of drops in water surface slope, with the goal of identifying reaches with high riffle density. Our slope-based predictions of pool-riffle morphology closely match the extent of pool-riffle reaches observed in the field. Average redd density in pool-riffle reaches is more than double the average redd density in reaches of other channel morphologies. Initial wavelet analysis suggests that riffle spacing may be longer in the lower reaches of Scott Creek and shorter in the high-redd density upper reaches, a finding that agrees with the hypothesis that spawning habitat is limited by riffle density. Our results suggest that high resolution topographic data can be successfully used to identify reaches of utilized spawning habitat based on grain size predictions and wavelet analysis of bedform spacing.

Pfeiffer, A.; Finnegan, N. J.; Hayes, S.

2013-12-01

459

Subseafloor basalts as fungal habitats  

NASA Astrophysics Data System (ADS)

The oceanic crust makes up the largest potential habitat for life on Earth, yet next to nothing is known about the abundance, diversity and ecology of its biosphere. Our understanding of the deep biosphere of subseafloor crust is, with a few exceptions, based on a fossil record. Surprisingly, a majority of the fossilized microorganisms have been interpreted or recently re-interpreted as remnants of fungi rather than prokaryotes. Even though this might be due to a bias in fossilization the presence of fungi in these settings can not be neglected. We have examined fossilized microorganisms in drilled basalt samples collected at the Emperor Seamounts in the Pacific Ocean. Synchrotron-radiation X-ray tomography microscopy (SRXTM) studies has revealed a complex morphology and internal structure that corresponds to characteristic fungal morphology. Chitin was detected in the fossilized hyphae, which is another strong argument in favour of a fungal interpretation. Chitin is absent in prokaryotes but a substantial constituent in fungal cell walls. The fungal colonies consist of both hyphae and yeast-like growth states as well as resting structures and possible fruit bodies, thus, the fungi exist in vital colonies in subseafloor basalts. The fungi have also been involved in extensive weathering of secondary mineralisations. In terrestrial environments fungi are known as an important geobiological agent that promotes mineral weathering and decomposition of organic matter, and they occur in vital symbiosis with other microorganisms. It is probable to assume that fungi would play a similar role in subseafloor basalts and have great impact on the ecology and on biogeochemical cycles in such environments.

Ivarsson, M.; Bengtson, S.

2013-12-01

460

Quantifying home range habitat requirements for bobcats (Lynx rufus) in Vermont, USA  

USGS Publications Warehouse

We demonstrate how home range and habitat use analysis can inform landscape-scale conservation planning for the bobcat, Lynx rufus, in Vermont USA. From 2005 to 2008, we outfitted fourteen bobcats with GPS collars that collected spatially explicit locations from individuals every 4. h for 3-4. months. Kernel home range techniques were used to estimate home range size and boundaries, and to quantify the utilization distribution (UD), which is a spatially explicit, topographic mapping of how different areas within the home range are used. We then used GIS methods to quantify both biotic (e.g. habitat types, stream density) and abiotic (e.g. slope) resources within each bobcat's home range. Across bobcats, upper 20th UD percentiles (core areas) had 18% less agriculture, 42% less development, 26% more bobcat habitat (shrub, deciduous, coniferous forest, and wetland cover types), and 33% lower road density than lower UD percentiles (UD valleys). For each bobcat, we used Akaike's Information Criterion (AIC) to evaluate and compare 24 alternative Resource Utilization Functions (hypotheses) that could explain the topology of the individual's UD. A model-averaged population-level Resource Utilization Function suggested positive responses to shrub, deciduous, coniferous forest, and wetland cover types within 1. km of a location, and negative responses to roads and mixed forest cover types within 1. km of a location. Applying this model-averaged function to each pixel in the study area revealed habitat suitability for bobcats across the entire study area, with suitability scores ranging between -1.69 and 1.44, where higher values were assumed to represent higher quality habitat. The southern Champlain Valley, which contained ample wetl