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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

Larval habitat duration and size at metamorphosis in frogs  

Microsoft Academic Search

The relationship between size at metamorphosis and adult size was studied in 12 closely-related species of frog from Malawi (Central Africa). These species of frogs breed in water of different durations, and occupy different habitats as adults. We could demonstrate no correlation between size at metamorphosis and size of adults when frogs were divided into groups on the basis of

Jeremy W. Patterson; Athol J. McLachlan

1989-01-01

3

Predicting Summer Site Occupancy for an Invasive Species, the Common Brushtail Possum (Trichosurus vulpecula), in an Urban Environment  

PubMed Central

Invasive species are often favoured in fragmented, highly-modified, human-dominated landscapes such as urban areas. Because successful invasive urban adapters can occupy habitat that is quite different from that in their original range, effective management programmes for invasive species in urban areas require an understanding of distribution, habitat and resource requirements at a local scale that is tailored to the fine-scale heterogeneity typical of urban landscapes. The common brushtail possum (Trichosurus vulpecula) is one of New Zealand’s most destructive invasive pest species. As brushtail possums traditionally occupy forest habitat, control in New Zealand has focussed on rural and forest habitats, and forest fragments in cities. However, as successful urban adapters, possums may be occupying a wider range of habitats. Here we use site occupancy methods to determine the distribution of brushtail possums across five distinguishable urban habitat types during summer, which is when possums have the greatest impacts on breeding birds. We collected data on possum presence/absence and habitat characteristics, including possible sources of supplementary food (fruit trees, vegetable gardens, compost heaps), and the availability of forest fragments from 150 survey locations. Predictive distribution models constructed using the programme PRESENCE revealed that while occupancy rates were highest in forest fragments, possums were still present across a large proportion of residential habitat with occupancy decreasing as housing density increased and green cover decreased. The presence of supplementary food sources was important in predicting possum occupancy, which may reflect the high nutritional value of these food types. Additionally, occupancy decreased as the proportion of forest fragment decreased, indicating the importance of forest fragments in determining possum distribution. Control operations to protect native birds from possum predation in cities should include well-vegetated residential areas; these modified habitats not only support possums but provide a source for reinvasion of fragments. PMID:23469277

Adams, Amy L.; Dickinson, Katharine J. M.; Robertson, Bruce C.; van Heezik, Yolanda

2013-01-01

4

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

PubMed

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

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

2014-05-01

5

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

USGS Publications Warehouse

Declines in many native fish populations have led to reassessments of management goals and shifted priorities from consumptive uses to species preservation. As management has shifted, relevant environmental characteristics have evolved from traditional metrics that described local habitat quality to characterizations of habitat size and connectivity. Despite the implications this shift has for how habitats may be prioritized for conservation, it has been rare to assess the relative importance of these habitat components. We used an information-theoretic approach to select the best models from sets of logistic regressions that linked habitat quality, size, and connectivity to the occurrence of chinook salmon (Oncorhynchus tshawytscha) nests. Spawning distributions were censused annually from 1995 to 2004, and data were complemented with field measurements that described habitat quality in 43 suitable spawning patches across a stream network that drained 1150 km 2 in central Idaho. Results indicated that the most plausible models were dominated by measures of habitat size and connectivity, whereas habitat quality was of minor importance. Connectivity was the strongest predictor of nest occurrence, but connectivity interacted with habitat size, which became relatively more important when populations were reduced. Comparison of observed nest distributions to null model predictions confirmed that the habitat size association was driven by a biological mechanism when populations were small, but this association may have been an area-related sampling artifact at higher abundances. The implications for habitat management are that the size and connectivity of existing habitat networks should be maintained whenever possible. In situations where habitat restoration is occurring, expansion of existing areas or creation of new habitats in key areas that increase connectivity may be beneficial. Information about habitat size and connectivity also could be used to strategically prioritize areas for improvement of local habitat quality, with areas not meeting minimum thresholds being deemed inappropriate for pursuit of restoration activities. ?? 2007 by the Ecological Society of America.

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

2007-01-01

6

Habitat destruction and metacommunity size in pen shell communities  

Microsoft Academic Search

Summary 1. In spatially structured communities, habitat destruction can have two effects: first, a main effect that occurs because of the loss of habitat area within a larger region, and a secondary effect due to changes in the spatial arrangement of local communities. Changes to the spatial arrangement can, in turn, affect the migration and extinction rates within local communities.

Pablo Munguia; Thomas E. Miller

2008-01-01

7

cDNA cloning, characterization, expression and recombinant protein production of leukemia inhibitory factor (LIF) from the marsupial, the brushtail possum ( Trichosurus vulpecula)  

Microsoft Academic Search

A reverse transcription technique using RNA templates combined with polymerase chain reaction (RT–PCR) was used to clone the cDNA fragment encoding the amino acid sequence of mature LIF protein of the marsupial, the brushtail possum, Trichosurus vulpecula. A PCR product with expected size, of 546bp, and termed tvLIF, was obtained using cDNA reverse-transcribed from total RNA isolated from possum uterus.

Shuliang Cui; Lynne Selwood

2000-01-01

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

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

10

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...

11

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

12

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

USGS Publications Warehouse

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

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

2003-01-01

13

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

PubMed Central

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

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

2013-01-01

14

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

15

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

16

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

PubMed

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

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

2010-03-01

17

TERRITORY SIZE IN MEGACERYLE ALCYON ALONG A STREAM HABITAT  

Microsoft Academic Search

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

WILLIAM JAMES DAVIS

18

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

19

Niche dimensions of New England cottontails in relation to habitat patch size  

Microsoft Academic Search

We examined physical condition, niche dimensions, and survival of New England cottontails (Sylvilagus transitionalis) that occupied 21 habitat patches of different sizes during winter. Rabbits on small patches (=2.5 ha) were predominantly males, and both sexes had lower body mass than individuals on large patches (=5.0 ha). Niche indices (ß, where ß ranges from 0 to 1. and values approaching

Michael S. Barbour; John A. Litvaitis

1993-01-01

20

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...

21

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

22

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

23

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

24

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

25

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

Microsoft Academic Search

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

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

2001-01-01

26

Social-network analysis of Mycobacterium bovis transmission among captive brushtail possums ( Trichosurus vulpecula)  

Microsoft Academic Search

Wild brushtail possums (Trichosurus vulpecula) are the main source of Mycobacterium bovis infection for New Zealand livestock. The disease is spread principally by infectious aerosol; therefore, social interactions determine disease transmission. In captive possums, den-sharing behaviour provided the greatest risk of tuberculosis transmission between animals. Den sharing between individual possums was used as the basic measurement for quantifying close proximity

L. A. L Corner; D. U Pfeiffer; R. S Morris

2003-01-01

27

FOODS OF THE AUSTRALIAN BRUSH-TAILED OPOSSUM (TRICHOSURUS VULPECULA) IN AN EXOTIC FOREST  

Microsoft Academic Search

SUMMARY: Foods of the Australian Brush-tailed opossum, Trichosurus vulpecula, were identified from stomach contents of 360 opossums collected from May 1975 to May 1976 in Ashley State Forest, Canterbury, New Zealand. Plant species eaten were identified with the aid of reference cuticles prepared from known plant species collected from the study area. Thirty different foods were identified, but only seven

B. WARBURTON

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

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

E-print Network

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

García-Berthou, Emili

30

Maternal influence on philopatry and space use by juvenile brushtail possums (Trichosurus vulpecula).  

PubMed

1. ?The causes of juvenile sex-biased philopatry and space use in mammals remain poorly understood, and results of previous research have been conflicting. Experimental interventions and manipulations on wild populations are rare, but can play an important role in establishing the factors governing offspring space use. 2. ?We experimentally removed mothers of independent juvenile brushtail possums from the maternal home range and examined changes in offspring space use with global positioning system collars. We examined the influence of mother absence on philopatric behaviour, and determined whether or not maternal presence affected offspring space use. 3. ?We fitted a longitudinal linear mixed effects model to demonstrate a change over time in the home range size of juveniles following experimental treatment by the removal of their mothers. When mothers were removed from the natal range, juveniles occupied significantly larger home range areas, with average increases of 175% in 95% kernel density estimates and 289% in minimum convex polygon estimates. This increase occurred within the first month following mother absence and was independent of juvenile sex. Home ranges of control juveniles did not change during the same time period. 4. ?Changes in the spatial structure of mammalian populations in response to removal of individuals have important implications for pest management. The impacts of management strategies which target particular individuals in a population may counteract conservation benefits through their effect on the space use of survivors. Studies involving experimental removals provide important information on consequences of control and also yield insights into the causes of mammalian space use, philopatric behaviours and ultimately dispersal. PMID:21155769

Blackie, Helen M; Russell, James C; Clout, Mick N

2011-03-01

31

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

32

Eye size variation reflects habitat and daily activity patterns in colubrid snakes.  

PubMed

The functioning of the vertebrate eye depends on its absolute size, which is presumably adapted to specific needs. Eye size variation in lidless and spectacled colubrid snakes was investigated, including 839 specimens belonging to 49 genera, 66 species and subspecies. Variations of adult eye diameters (EDs) in both absolute and relative terms between species were correlated with parameters reflecting behavioral ecology. In absolute terms, eye of arboreal species was larger than in terrestrial and semiaquatic species. For diurnal species, EDs of terrestrial species do not differ from semiaquatic species; for nocturnal species the ED of terrestrial species is larger than fossorial species but not different from semiaquatic species. In relative terms, ED did not differ significantly by habitat for diurnal species. Although the ED of terrestrial species is larger than fossorial species there were no differences for nocturnal species between semiaquatic and fossorial snakes. In contrast to other vertebrates studied to date, colubrid EDs in absolute and relative terms are larger in diurnal than in nocturnal species. These observations suggest that among colubrid snakes, eye size variation reflects adaptation to specific habitats, foraging strategies and daily activities, independently of phylogeny. PMID:22549850

Liu, Yang; Ding, Li; Lei, Juan; Zhao, Ermi; Tang, Yezhong

2012-08-01

33

Design and Parametric Sizing of Deep Space Habitats Supporting NASA'S Human Space Flight Architecture Team  

NASA Technical Reports Server (NTRS)

NASA's Human Space Flight Architecture Team (HAT) is a multi-disciplinary, cross-agency study team that conducts strategic analysis of integrated development approaches for human and robotic space exploration architectures. During each analysis cycle, HAT iterates and refines the definition of design reference missions (DRMs), which inform the definition of a set of integrated capabilities required to explore multiple destinations. An important capability identified in this capability-driven approach is habitation, which is necessary for crewmembers to live and work effectively during long duration transits to and operations at exploration destinations beyond Low Earth Orbit (LEO). This capability is captured by an element referred to as the Deep Space Habitat (DSH), which provides all equipment and resources for the functions required to support crew safety, health, and work including: life support, food preparation, waste management, sleep quarters, and housekeeping.The purpose of this paper is to describe the design of the DSH capable of supporting crew during exploration missions. First, the paper describes the functionality required in a DSH to support the HAT defined exploration missions, the parameters affecting its design, and the assumptions used in the sizing of the habitat. Then, the process used for arriving at parametric sizing estimates to support additional HAT analyses is detailed. Finally, results from the HAT Cycle C DSH sizing are presented followed by a brief description of the remaining design trades and technological advancements necessary to enable the exploration habitation capability.

Toups, Larry; Simon, Matthew; Smitherman, David; Spexarth, Gary

2012-01-01

34

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

35

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

36

Behavior-Based Assessment of the Auditory Abilities of Brushtail Possums  

ERIC Educational Resources Information Center

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

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

2011-01-01

37

Absence of Ross River virus amongst Common brushtail possums ( Trichosurus vulpecula ) from metropolitan Sydney, Australia  

Microsoft Academic Search

Ross River virus (RRV) is a mosquito-transmitted Alphavirus emerging in urban centres throughout Australia. The Common brushtail\\u000a possum (Trichosurus vulpecula), a native marsupial that has successfully adapted to human settlement, has been implicated as a maintenance reservoir for\\u000a RRV. In the present study, RRV exposure was assessed amongst 72 urban-adapted possums from Northern Sydney and ten possums\\u000a from a woodland

Nichola J. Hill; Michelle L. Power; Elizabeth M. Deane

2009-01-01

38

Endothermy in African platypleurine cicadas: the influence of body size and habitat (Hemiptera: Cicadidae).  

PubMed

The platypleurine cicadas have a wide distribution across Africa and southern Asia. We investigate endothermy as a thermoregulatory strategy in 11 South African species from five genera, with comparisons to the lone ectothermic platypleurine we found, in an attempt to ascertain any influence that habitat and/or body size have on the expression of endothermy in the platypleurine cicadas. Field measurements of body temperature (T(b)) show that these animals regulate T(b) through endogenous heat production. Heat production in the laboratory elevated T(b) to the same range as in animals active in the field. Maximum T(b) measured during calling activity when there was no access to solar radiation ranged from 13.2 degrees to 22.3 degrees C above ambient temperature in the five species measured. The mean T(b) during activity without access to solar radiation did not differ from the mean T(b) during diurnal activity. All platypleurines exhibit a unique behavior for cicadas while warming endogenously, a temperature-dependent telescoping pulsation of the abdomen that probably functions in ventilation. Platypleurines generally call from trunks and branches within the canopy and appear to rely on endothermy even when the sun is available to elevate T(b), in contrast to the facultative endothermy exhibited by New World endothermic species. The two exceptions to this generalization we found within the platypleurines are Platypleura wahlbergi and Albanycada albigera, which were the smallest species studied. The small size of P. wahlbergi appears to have altered their thermoregulatory strategy to one of facultative endothermy, whereby they use the sun when it is available to facilitate increases in T(b). Albanycada albigera is the only ectothermic platypleurine we found. The habitat and host plant association of A. albigera appear to have influenced the choice of ectothermy as a thermoregulatory strategy, as the species possesses the metabolic machinery to elevate to the T(b) range observed in the endothermic species. Therefore, size and habitat appear to influence the expression of thermoregulatory strategies in African platypleurine cicadas. PMID:15547799

Sanborn, Allen F; Villet, Martin H; Phillips, Polly K

2004-01-01

39

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

40

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

PubMed Central

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

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

2012-01-01

41

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

USGS Publications Warehouse

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

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

2012-01-01

42

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

43

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

USGS Publications Warehouse

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

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

2009-01-01

44

Habitat use and group size of pied cormorants ( Phalacrocorax varius ) in a seagrass ecosystem: possible effects of food abundance and predation risk  

Microsoft Academic Search

Both food abundance and predation risk may influence habitat use decisions. However, studies of habitat use by birds in marine environments have focused only on food abundance. I investigated the possible influences of food abundance and predation risk from tiger sharks (Galeocerdo cuvier) on habitat use by pied cormorants (Phalacrocorax varius) over two spatial scales and on cormorant group size.

M. R. Heithaus

2005-01-01

45

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

46

Habitat-mediated size selection in endangered Atlantic salmon fry: selectional restoration assessment  

PubMed Central

Preservation of adaptive variation is a top priority of many species restoration programs, but most restoration activities are conducted without direct knowledge of selection that might foster or impair adaptation and restoration goals. In this study, we quantified geographic variation in selection on fry size of endangered Atlantic salmon (Salmo salar) during the 6-week period immediately following stocking in the wild. We also used a model selection approach to assess whether habitat variables influence patterns of such selection. We found evidence for significant size-selection in five out of six selection trials. Interestingly, the strength and pattern of selection varied extensively among sites, and model selection suggested that this variation in phenotypic selection was related to geographic variation in the presence of large woody debris and the slope of the stream gradient. The strong selection differentials we observed should be a concern for endangered salmon restoration, whether they reflect natural processes and an opportunity to maintain adaptation, or an indicator of the potentially deleterious phenotypic consequences of hatchery practices.

Bailey, Michael M; Kinnison, Michael T

2010-01-01

47

Predation by xanthid crabs on early post-settlement gastropods: the role of prey size, prey density, and habitat complexity  

Microsoft Academic Search

Small predators in marine benthic communities create a hazardous environment for newly settled invertebrates, especially for the smallest individuals. To explore the effects of predation on a newly settled gastropod, queen conch (Strombus gigas Linnaeus), by a xanthid crab (Micropanope sp.), prey size, prey density, and habitat complexity were manipulated in five laboratory experiments. All crabs >3.1 mm CW killed

Melody Ray-Culp; Megan Davis; Allan W Stoner

1999-01-01

48

vol. 172, no. 6 the american naturalist december 2008 Why Are Predators More Sensitive to Habitat Size than Their  

E-print Network

. In one habitat, dwarf forests, detrital biomass became decoupled from bromeliad size, which also caused University Boulevard, Vancouver, British Columbia V6T 1Z4, Canada; 2. Biodiversity Research Centre Experimental Forest, Puerto Rico; 5. Department of Botany, University of British Columbia, 6270 University

Srivastava, Diane

49

Patch occupancy in Coenonympha tullia (Muller, 1764) (Lepidoptera: Satyrinae): habitat quality matters as much as patch size and isolation  

Microsoft Academic Search

Patch occupancy by Coenonympha tullia has been surveyed in 166 sites in Northumberland, UK. It was found in 117 of them and absent in 37. Weather conditions were too poor to determine its presence at a further 12 sites. Differences in habitat quality among sites account for patch occupancy as successfully (R2 = 48%) as isolation and patch size jointly

Roger L. H. Dennis; Harry T. Eales

1997-01-01

50

Patterns in the abundance and size-distribution of syngnathid fishes among habitats in a seagrass-dominated marine environment  

NASA Astrophysics Data System (ADS)

Syngnathid fishes were sampled using a 1 m wide beam trawl during the day and night in each season from summer 1996/1997 to summer 1997/1998 in five habitat types in an approximately 90 km 2 area located on the lower west coast of Australia. The seagrasses Amphibolis griffithii, Posidonia sinuosa and Posidonia coriacea and shallow unvegetated sand were all in depths of 4-9 m, while deep habitat, which comprised mainly bare sand with isolated patches of the seagrasses Heterozostera tasmanica and Halophila ovalis, occurred at depths of 12-16 m. While A. griffithii and P. sinuosa each formed dense monospecific meadows, P. coriacea occurred in sparse clumps surrounded by areas of bare sand and patches of H. tasmanica. While catches of spotted pipefish Stigmatopora argus occurred mainly in P. sinuosa and P. coriacea, individuals of this species that exceeded ca. 55 mm in snout-vent length were far more abundant in the former habitat whereas smaller fish occurred mostly in the latter. Densities of S. argus were similar in P. sinuosa and P. coriacea, but differed between seasons, and a season/habitat interaction was present. In contrast, wide-bodied pipefish Stigmatopora nigra were collected mainly in P. coriacea and deep habitat and, although the densities were greater in P. coriacea than in deep habitat, the size-distributions of this species in these habitats were similar. Notably, S. nigra was never collected in P. sinuosa. Although less abundant than the above pipefish, the long-snouted pipefish Vanacampus poecilolaemus was collected almost exclusively in P. sinuosa. Few syngnathids were collected from shallow unvegetated sand or from A. griffithii, which differed markedly in plant structure from both Posidonia species. It is suggested that these syngnathid species occupy habitats that best enable them to remain inconspicuous to predators. Both S. argus and S. nigra have green or brown colouration and mimic strap-like seagrass leaves which they grasp with prehensile tails, whereas V. poecilolaemus, which is dark coloured and lacks a prehensile tail, most likely lies among the rich detrital material that accumulates beneath the dense P. sinuosa canopy. The movement of larger-sized S. argus from the narrow-leaved P. coriacea to the relatively broad-leaved P. sinuosa may enable the adults of this species to be better camouflaged than if they had remained in the former habitat. As they grow to only approximately half the size of S. argus, S. nigra of all sizes could remain concealed in narrow-leaved seagrasses like P. coriacea and H. tasmanica. The presence of more S. nigra in P. coriacea compared with deep habitat probably reflected the greater expanse of seagrass canopy available in the former habitat, while the inability of either Stigmatopora species to mimic the short leaves of A. griffithii could help to explain their scarcity in this seagrass. The almost total absence of S. nigra and small S. argus from P. sinuosa could be due to their inability to grasp the relatively broad leaves of this seagrass or the presence in this habitat of predators that selectively predate these smaller pipefish. That very few small-sized S. argus were present in P. coriacea during winter 1997, despite the fact that males of both Stigmatopora species carried broods of young in all seasons, suggests that the reproductive output of this species and/or the survival of recruits varied during the study period.

Kendrick, A. J.; Hyndes, G. A.

2003-07-01

51

Serologic Survey for Toxoplasma gondii and Neospora caninum in the Common Brushtail Possum (Trichosurus vulpecula) from Urban Sydney, Australia  

Microsoft Academic Search

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 (Toxoplasma gondii) or dogs (Neospora caninum), yet it is unknown to what extent urban T.

Jutta Eymann; Catherine A. Herbert; Desmond W. Cooper; J. P. Dubey

2006-01-01

52

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

PubMed

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

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

2012-03-01

53

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

54

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

PubMed

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

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

2010-08-01

55

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

NASA Technical Reports Server (NTRS)

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

Curreri, Peter A.; Detweiler, Michael

2010-01-01

56

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

PubMed Central

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

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

2012-01-01

57

Variation in relative growth rate and its components in the annual Polygonum aviculare in relation to habitat disturbance and seed size  

Microsoft Academic Search

Polygonum aviculare is an annual weedy species showing extensive genetic variation in seed and leaf size and colonizing various types of man-disturbed habitats. A growth analysis was conducted on 12 genotypes representative of three regimes of disturbance of natural habitat (trampling, weeding, and no disturbance in the course of the growing season), grown under productive conditions in order to test

P. Meerts; E. Garnier

1996-01-01

58

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

59

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

60

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

PubMed

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

Emura, Shoichi; Okumura, Toshihiko; Chen, Huayue

2014-01-01

61

Laying date and clutch size of Great Tits (Parus major) in the Mediterranean region: a comparison of four habitat types  

Microsoft Academic Search

Summary Laying data and clutch size of Great Tits were studied in four different habitats in eastern Spain: two holm oak(Quercus ilex) forests, at 500 and 900–950 m a.s.l., a zeen oak(Quercus faginea) forest, at 900–1100 m a.s.l., a pine(Pinus sylvestris) forest, at 1000–1050 m a.s.l., and orange(Citrus aurantium) plantations, at 30 m a.s.l. All sites were placed at about

Eduardo J. Beldal; Emilio Barba; José A. Gil-Delgado; Domingo J. Iglesias; Germán M. López; Juan S. Monrós

1998-01-01

62

Habitat-Specific variation in eyespot size of a benthic cladoceran  

Microsoft Academic Search

Pigmented eyespot size of the benthic cladoceran Simocephalus exspinosus was measured in individuals sampled from four freshwater ponds that differed in the extent of visually-oriented predation. In ponds with such predation (from fish, salamander larvae, and dragonfly nymphs), eyespot size was found to be significantly smaller, relative to body size, than in a pond without visually-oriented predation. Reduction in pigmented

Michael J. Konecny; Carmine A. Lanciani; Charles P. White

1982-01-01

63

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

PubMed

Environmental gradients often lead to the parallel evolution of populations and species. To what extent do such gradients also lead to parallel evolution of the sexes? We used guppies (Poecilia reticulata) to examine the parallel and independent (sex-specific) aspects of population divergence in response to predation and habitat features. Geometric morphometrics was used to analyse size and shape variation for 1335 guppies from 27 to 31 sites sampled in each of 2 years. Body size showed strong parallel population divergence; both sexes were larger at sites with a more open canopy and with higher flow. Body shape showed a mixture of parallel and independent population divergence. The strongest and most consistent effects were (1) high-predation sites had males with smaller heads and deeper caudal peduncles, (2) open-canopy sites had females with smaller heads and more distended abdomens and (3) high-flow sites had males and females with smaller heads and deeper caudal peduncles. PMID:16674571

Hendry, A P; Kelly, M L; Kinnison, M T; Reznick, D N

2006-05-01

64

Influence of habitat on density, species richness, and size distribution of groupers in the upper Florida Keys, United States of America and central Bahamas  

Microsoft Academic Search

The influence of habitat on the density, species richness, and size distribution of groupers (Pisces: Serranidae) was studied in the upper Florida Keys, USA and the Exuma Cays Land and Sea Park (ECLSP), central Bahamas. Four reef types were examined: relict spur and groove; high-relief spur and groove; relict reef flat; and patch reefs.The size distribution of groupers differed among

Robert Daniel Sluka

1995-01-01

65

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

66

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

EPA Science Inventory

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

67

Parasite assemblages of European bitterling (Rhodeus amarus), composition and effects of habitat type and host body size.  

PubMed

Parasite community composition of European bitterling (Rhodeus amarus), the only bitterling species occurring on the European continent, was investigated in 16 different localities from four European sea drainages during 1998-2007. A total of 41 species of metazoan parasites was identified. Nine parasite species are new records for European bitterling, namely Dactylogyrus rarissimus, D. suecicus, D. yinwenyingae, Gyrodactylus vimbi, Sphaerostomum globiporum, Petasiger sp., Paryphostomum radiatum, Ichthyocotylurus variegatus and Posthodiplostomum brevicaudatum. The specialist Gyrodactylus rhodei was the most widely distributed and one of the most prevalent species. The most frequent digenean species, represented by larval stages, was Metorchis xanthosomus. The parasite community of European bitterling was characterised by the dominance of generalists and parasites with autogenic life cycles. The rare occurrence of strictly endoparasitic species reflected the specific diet of the fish host. The character of the habitat significantly affected the parasite assemblages of bitterling. The greatest similarity was associated with lentic habitats (gravel pits and oxbows) and the lowest similarity between gravel pits and rivers. Juvenile bitterling from 8mm in length upwards were colonised by metazoan parasites, firstly by the monogenean G. rhodei. Host body size was positively correlated with parasite species richness, but the variability explained by length was low. PMID:18180954

Dávidová, Martina; Ondracková, Markéta; Jurajda, Pavel; Gelnar, Milan

2008-04-01

68

Isozyme variability of the wetland specialist Swertia perennis (Gentianaceae) in relation to habitat size, isolation, and plant fitness.  

PubMed

We examined the effects of size and spatial isolation of fens on the isozyme variability of 17 populations of Swertia perennis. This long-lived perennial is a locally abundant fen specialist in Switzerland, where wetlands have been strongly fragmented. Isozyme variability was comparable to other outcrossing plants (A = 1.53, AP(p) = 2.01, P(p) = 42.5, H(o) = 0.113, H(e) = 0.139). F statistics indicated both inbreeding within and differentiation between populations (F(IS) = 0.076, F(IT) = 0.194, F(ST) = 0.128), with moderate gene flow between populations (N(e)m = 1.703). Populations in small, isolated fens had reduced genetic variability and the highest within-population inbreeding coefficients (F(IS)). Isozyme variability was significantly associated with vegetative fitness traits (MANOVA), and the magnitude of leaf herbivory decreased as the percentage of polymorphic loci increased. These data suggest that the reduced genetic variability of S. perennis in small, isolated populations may reduce plant fitness, thereby increasing susceptibility to herbivore damage. Our study also shows that habitat fragmentation can reduce the genetic variability of populations of fairly common habitat specialists, which so far have attracted less conservation attention than rare species. PMID:21665680

Lienert, Judit; Fischer, Markus; Schneller, Jakob; Diemer, Matthias

2002-05-01

69

Size and structure of crayfish (Astacus astacus) populations on different habitats in Finland  

Microsoft Academic Search

The many inland waters in Finland make crayfish production an important potential resource. The rational utilization and management of this resource requires knowledge of the size and structure of the crayfish populations. The difficulties often encountered in catching crayfish complicate population studies. Mark-recapture and electric fishing have been used in the studies. The number of adult crayfish measuring more than

K. Westman; M. Pursiainen

1982-01-01

70

Assessing the distribution, habitat, and population size of the threatened Dupont's lark Chersophilus  

E-print Network

Chersophilus duponti in Morocco: lessons for conservation JesU´ s T. GarcI´ a, Francisco SuA´ rez, Vicente report on the breeding distribution of Dupont's lark in Morocco, probably the largest pop- ulation in its). However, the precise ranges, pop- ulation sizes and, most importantly, population trends of these North

Oñate, Juan J.

71

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

PubMed Central

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

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

2009-01-01

72

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

PubMed

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

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

2014-07-01

73

Associations with habitat versus geographic cohesiveness: size and shape of Bembicium vittatum Philippi (Gastropoda: Littorinidae) in the Houtman Abrolhos Islands  

Microsoft Academic Search

In the Houtman Abrolhos Islands, Western Australia, the direct-developing littorine snail Bembicium vittatum occupies a wide range of habitats, which are replicated across the three major groups of islands. Earlier studies showed that allozyme similarities followed patterns related to gene flow, independent of habitat, providing an excellent opportunity to test for associations with habitat for traits more likely to be

MICHAEL S JOHNSON; ROBERT BLACK

2000-01-01

74

The Divergence of Echolocation Frequency in Horseshoe Bats: Moth Hearing, Body Size or Habitat?  

Microsoft Academic Search

A phylogenetic approach was used to test three hypotheses regarding the evolution of diversity in the echolocation frequencies\\u000a used by horseshoe bats (family Rhinolophidae, genus Rhinolophus): 1) Allotonic Frequency Hypothesis (high frequency echolocation in the Rhinolophidae resulted from coevolution with moth\\u000a hearing); 2) Allometry Hypothesis (echolocation frequency is negatively scaled with body size and evolutionary changes in\\u000a echolocation frequencies are

Samantha Stoffberg; David S. Jacobs; Conrad A. Matthee

2011-01-01

75

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

76

Effects of Predation Risk and Foraging Return on the Diel Use of Vegetated Habitat by Two Size-Classes of Bluegills  

Microsoft Academic Search

Little is known about nocturnal habitat selection by fishes under the risk of predation. Using a photoperiod of 15 h light : 9 h dark, we quantified the diel use of artificial macrophytes and open water by two size-classes of bluegill Lepomis macrochirus when the open water was empty (control), contained food, or contained both a caged predator and food.

Daniel E. Shoup; Robert E. Carlson; Robert T. Heath

2003-01-01

77

Comparative spatial distribution, size, biomass and growth rate of two varieties of bracken fern (Pteridium aquilinum L. Kuhn) in a neotropical montane habitat  

Microsoft Academic Search

A comparative field study of caudatum and arachnoideum, the two Pteridium aquilinum varieties of the caudatum subspecies known to grow in the neotropics, was performed in a montane savanna habitat of the Venezuelan Andes that was affected by wildfire. Frond size, ramet density and spatial distribution, blade and rhizome biomass, and frond elongation and expansion rates were measured in separate,

Miguel E. Alonso-Amelot

1996-01-01

78

Effects of air temperature, air movement and artificial rain on the heat production of brushtail possums (Trichosurus vulpecula): An exploratory study  

Microsoft Academic Search

Two groups of six mature brushtail possums (Trichosurus vulpecula) were housed in two respiration chambers, and their heat production, whole body conductance and lower critical temperatures were measured under a variety of simulated weather patterns. The possums were subjected to ambient temperatures of 30, 20 and 3 °C. At 20 and 3 °C, the animals were exposed to near still

Q. G. W. van den Oord; E. J. A. van Wijk; I. W. Lugton; R. S. Morris; C. W. Holmes

1995-01-01

79

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

Microsoft Academic Search

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

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

2009-01-01

80

Using Sodium-Chloride Tracers and Grain Size Analysis to Determine Hyporheic Permeability in Salmonid Spawning Habitat  

NASA Astrophysics Data System (ADS)

Embryonic mortality rates of salmonids are greatly affected by gravel permeability and grain size distributions within the host gravel. Typical permeability testing methods use a single standpipe to measure the permeability. For studies on the American and Feather Rivers in northern California, tracer tests were used to measure seepage velocity using a main "injection" well and several downstream monitoring wells. Bulk samples and pebble counts were used to measure grain size. Measurements were recorded at approximately 30cm depth in the gravel, where salmonid species typically lay their eggs. Sites were examined before and after stream restoration to compare subsurface habitat conditions. During each tracer test, a super-saturated NaCl solution was introduced into an "injection" standpipe with a short well screen located 30cm deep in the gravel. Identical downstream standpipes contained conductivity meters that sensed the NaCl as it passed through the gravel, causing a spike in specific conductance. Plotting the peak conductance against the arrival time allowed a seepage velocity to be measured in cm/second. Seepage velocity ranged from 0.2 - 0.7 cm/sec in restored gravel, and was less than 1.6 x 10-4 cm/sec in some un-restored areas. Grain size analysis showed that un-restored areas had an armored surface with d50 values ranging from 4-10 cm, while the subsurface showed excessive fine material supporting large grains smaller than those in the surface sample with d50 values ranging from 1.3 - 3.0 cm. Restored areas were found to contain a well sorted composition containing little to no fine material and a subsurface which closely matched the surface showing d50 values from 1.6 - 3.8 cm. Comparing results of tracer tests with grain size distributions in both restored and un-restored spawning gravels gives an indication of the relative health of a particular portion of a hyporheic river system, and the relative success of some restoration projects.

Rosenbery, J. W.; Janes, M. K.; Heffernan, J. E.; Horner, T.

2012-12-01

81

Similarity of Body Size in Queens of the Wood ant Formica aquilonia from Optimal and Sub-Optimal Habitats Indicates a Strong Heritable Component  

PubMed Central

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

82

Rapid absorption of dietary 1,8-cineole results in critical blood concentration of cineole and immediate cessation of eating in the common brushtail possum (Trichosurus vulpecula).  

PubMed

The blood concentration of 1,8-cineole and its metabolites was measured in six male brushtail possums while they voluntarily fed on diets laced with varying concentrations of cineole for 3 d. On the third day, blood samples were collected during and after each bout of feeding for 3 hr. Blood cineole was measured by using headspace solid-phase microextraction (SPME), while cineole metabolites were measured by liquid-liquid extraction followed by gas chromatography-mass spectroscopy. Feeding patterns were measured by continual recording of residual food weight and time. Cineole absorption was rapid, resulting in a peak blood concentration at the end of each feeding bout. The blood concentration of cineole did not exceed a critical value (51.8 +/- 14.1 micromol/l) regardless of the concentration in the diet. Food and, therefore, cineole intake was regulated. The amount of food ingested in the first feeding bout decreased from 236 +/- 52 g on the control diet to 36 +/- 20 g on the 4% cineole diet. The amount of cineole ingested in the first bout (1.18 +/- 1.10 g) was the same regardless of the dietary concentration and was controlled by the size of the meal. Total food eaten during the 7-hr feeding session decreased by 64% from 368 +/- 94 g (control diet) to 131 +/- 52 g (4% diet). Total cineole intake increased from 2.47 +/- 0.60 g (1% diet) to 5.05 +/- 2.41 g (4% diet). Cineole metabolites accumulated throughout the sampling period and were generally still rising at the end of blood sampling period. Blood levels of metabolites were at least 10-fold higher than cineole levels. The immediate control of feeding seems to be regulated by blood levels of cineole, whereas metabolites are likely to be more important in regulating the chronic ingestion of cineole. PMID:16365704

Boyle, Rebecca R; McLean, Stuart; Brandon, Sue; Wiggins, Natasha

2005-12-01

83

DOI: 10.4038/cjsbs.v42i1.5898 The Association between Body-size and Habitat-type in Tiger Beetles (Coleoptera, Cicindelidae) of Sri Lanka  

E-print Network

Body size is an important feature of an animal that is linked with its life history, morphology, physiology and ecology. Understanding the association between body size and habitat type of an animal and the underlying causes for this are important for determining their distribution. The present study examines the association between body size and habitat types of tiger beetles in Sri Lanka and the environmental correlations for these associations. Morphometric parameters of tiger beetles and environmental parameters (air temperature, solar radiation, relative humidity, wind speed and, the colour, temperature, moisture content, pH and salinity of soil) in each habitat were recorded. Ten tiger beetle species were found from 37 locations which included coastal, riverine, urban and reservoir habitats. Species with larger body and mandible sizes prefer coastal and reservoir habitats with high wind speed, low soil moisture and high soil pH, whereas species with smaller body and mandible sizes prefer riverine habitats with low wind speed, high soil moisture and low soil pH. Species with smaller body size may also prefer urban habitats which may be due to similarity of environmental conditions that prevails in these two sites. These findings will assist in predicting the distribution of tiger beetles within various habitat types of Sri Lanka. Key words: body length, mandible length, climatic parameters, soil parameters

Ima D. Dangalle; Nirmalie Pallewatta; Alfried P. Vogler

2012-01-01

84

Comparing simulated wildfire effects to jam distribution and habitat quality in an intermediate-sized stream 10 years after a high intensity fire  

NASA Astrophysics Data System (ADS)

Large wood governs channel morphology and determines the quality and distribution of aquatic habitat in many forested river networks. This is particularly true in streams that contain both key pieces large enough to form morphologically effective jams, as well as smaller mobile wood. In these streams, jams create spawning habitat by retaining sediment, increase rearing and over-wintering habitat by forming pools, and force avulsions which create side channels. To explore the effects of wildfire-induced increases in wood loading on channel morphology and aquatic habitat we have applied the stochastic reach-scale channel simulator (RSCS) to a case study of Fishtrap Creek, an intermediate-sized stream in the interior of British Columbia which experienced a high intensity fire in 2003. As predicted by model simulations, high quality spawning, rearing, and over-wintering habitats, as well as multi-thread channels, are found exclusively in association with wood, while plane-bed morphologies dominate where wood is absent. However, valley confinement and glacial legacy exert an important control on the magnitude of the impacts of the fire-derived wood; where the stream is confined, wood is suspended and morphologically ineffective, while un-confined segments contain high effective wood loads, multi-thread channels, and abundant aquatic habitat. These findings suggest that the morphologic effects of wood are highly dependent on valley geometry, which is in turn dictated by glacial legacy throughout much of North America, and that the impacts of valley confinement on the effectiveness of introduced wood must be considered in future model iterations. Plane bed morphology typical of reaches without large wood present Complex forced pool-riffle morphology typical of reaches with high wood loading

Davidson, S. L.; Eaton, B. C.

2013-12-01

85

Movements and Habitat Use of Eastern Foxsnakes (Pantherophis gloydi) in Two Areas Varying in Size and Fragmentation  

E-print Network

that vary in their degree of fragmentation. As predators, snakes are an important component of ecosystems scale. Within the smaller habitat patch, however, these preferences were accentuated with snakes and landscapes. Snakes are significant predators of birds, mammals, am- phibians, and reptiles (Schwaner

Blouin-Demers, Gabriel

86

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

87

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

Microsoft Academic Search

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

David P. Watts

1998-01-01

88

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

89

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

PubMed

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

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

2014-07-01

90

Urban agricultural land use and characterization of mosquito larval habitats in a medium-sized town of Côte d'Ivoire.  

PubMed

Urban agriculture is common across Africa and contributes to the livelihoods of urban dwellers. Some crop systems create suitable mosquito breeding sites and thus might affect malaria transmission. The purpose of this study was to identify, map, and characterize potential mosquito breeding sites in agricultural land use zones in a medium-sized town of western Côte d'Ivoire and to assess risk factors for productive Anopheles breeding sites. Two surveys were carried out; one toward the end of the rainy season and the second one during the dry season. In all identified potential mosquito breeding sites, two experienced entomologists searched for the presence of Anopheles larvae and pupae with a standardized technique. Totals of 369 and 589 sites were found in the rainy and dry seasons, respectively, mainly in vegetable gardens and irrigated rice fields. Anopheles larvae were present in 50.7% and 42.4% of the sites investigated during the rainy and dry seasons, respectively. Typical Anopheles larval habitats were characterized by the presence of algae, the absence of floating vegetation, and the co-occurrence of Culex larvae. The highest Anopheles larval productivity was observed in rice paddies, agricultural trenches between vegetable patches, and irrigation wells. An indirect link could be established between the occurrence of productive Anopheles breeding sites and agricultural land use through specific man-made habitats, in particular agricultural trenches, irrigation wells, and rice paddies. Our findings have important bearings for the epidemiology and control of urban malaria in sub-Saharan Africa. PMID:17249350

Matthys, Barbara; N'Goran, Eliézer K; Koné, Moussa; Koudou, Benjamin G; Vounatsou, Penelope; Cissé, Guéladio; Tschannen, Andres B; Tanner, Marcel; Utzinger, Jürg

2006-12-01

91

Hierarchical Bayesian modelling with habitat and time covariates for estimating riverine fish population size by successive removal method  

Microsoft Academic Search

We present a hierarchical Bayesian modelling (HBM) framework for estimating riverine fish population size from successive removal data via electrofishing. It is applied to the estimation of the population of Atlantic salmon (Salmo salar) juveniles in the Oir River (France). The data set consists of 10 sampling sites sampled by one or two removals over a period of 20 years

Etienne Rivot; Etienne Prévost; Anne Cuzol; Jean-Luc Baglinière; Eric Parent

2008-01-01

92

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

PubMed

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

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

2012-01-01

93

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...

94

High levels of habitat loss and fragmentation limit reproductive success by reducing home range size and provisioning rates of Northern saw-whet owls  

Microsoft Academic Search

Studies of the effects of habitat fragmentation have been heavily biased toward population and community questions, with less attention on the effects of habitat loss and fragmentation on individual behaviour and reproduction. We studied the effects of habitat amount and configuration on the foraging behaviour, provisioning rates and physiological condition of breeding male northern saw-whet owls (Aegolius acadicus) nesting in

Heather Lynn Hinam; Colleen Cassady St. Clair

2008-01-01

95

Variations of flower size and reproductive traits in self-incompatible Trollius ranunculoides (Ranunculaceae) among local habitats at Alpine Meadow  

Microsoft Academic Search

For plants that rely on animals for pollination, the ability to attract the animals to their flowers can be a crucial component\\u000a of fitness. A large number of studies have documented pollinators to be important selective agents driving the evolution of\\u000a flower size and correlated traits on a large scale. In this paper, we studied variations of reproductive traits in

Zhigang Zhao; Yanlong He; Mantang Wang; Guozhen Du

2007-01-01

96

Isozyme variability of the wetland specialist Swertia perennis (Gentianaceae) in relation to habitat size, isolation, and plant fitness  

Microsoft Academic Search

We examined the effects of size and spatial isolation of fens on the isozyme variability of 17 populations of Swertia perennis. This long-lived perennial is a locally abundant fen specialist in Switzerland, where wetlands have been strongly fragmented. Isozyme variability was comparable to other outcrossing plants (A 5 1.53, APp 5 2.01, Pp 5 42.5, Ho 5 0.113, He 5

JUDIT LIENERT; MARKUS FISCHER; JAKOB SCHNELLER; MATTHIAS DIEMER

2002-01-01

97

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

PubMed

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

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

2013-07-01

98

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

2013-01-01

99

Effects of habitat fragmentation, population size and demographic history on genetic diversity: the Cross River gorilla in a comparative context.  

PubMed

In small and fragmented populations, genetic diversity may be reduced owing to increased levels of drift and inbreeding. This reduced diversity is often associated with decreased fitness and a higher threat of extinction. However, it is difficult to determine when a population has low diversity except in a comparative context. We assessed genetic variability in the critically endangered Cross River gorilla (Gorilla gorilla diehli), a small and fragmented population, using 11 autosomal microsatellite loci. We show that levels of diversity in the Cross River population are not evenly distributed across the three genetically identified subpopulations, and that one centrally located subpopulation has higher levels of variability than the others. All measures of genetic variability in the Cross River population were comparable to those of the similarly small mountain gorilla (G. beringei beringei) populations (Bwindi and Virunga). However, for some measures both the Cross River and mountain gorilla populations show lower levels of diversity than a sample from a large, continuous western gorilla population (Mondika, G. gorilla gorilla). Finally, we tested for the genetic signature of a bottleneck in each of the four populations. Only Cross River showed strong evidence of a reduction in population size, suggesting that the reduction in size of this population was more recent or abrupt than in the two mountain gorilla populations. These results emphasize the need for maintaining connectivity in fragmented populations and highlight the importance of allowing small populations to expand. PMID:18521886

Bergl, Richard A; Bradley, Brenda J; Nsubuga, Anthony; Vigilant, Linda

2008-09-01

100

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

101

Demographic Consequences of Terrestrial Habitat Loss for Pool-Breeding Amphibians: Predicting Extinction Risks Associated with Inadequate Size of Buffer Zones  

Microsoft Academic Search

Much of the biodiversity associated with isolated wetlands requires aquatic and terrestrial habitat to maintain viable populations. Current federal wetland regulations in the United States do not protect isolated wetlands or extend protection to surrounding terrestrial habitat. Consequently, some land managers, city planners, and policy makers at the state and local levels are making an effort to protect these wetland

ELIZABETH B. HARPER; TRACY A. G. RITTENHOUSE; RAYMOND D. SEMLITSCH

2008-01-01

102

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

PubMed

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

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

2014-04-01

103

The stoichiometry and antenna size of the two photosystems in marine green algae, Bryopsis maxima and Ulva pertusa, in relation to the light environment of their natural habitat.  

PubMed

The stoichiometry and antenna sizes of the two photosystems in two marine green algae, Bryopsis maxima and Ulva pertusa, were investigated to examine whether the photosynthetic apparatus of the algae can be related to the light environment of their natural habitat. Bryopsis maxima and Ulva pertusa had chlorophyll (Chl) a/b ratios of 1.5 and 1.8, respectively, indicating large levels of Chl b, which absorbs blue-green light, relative to Chl a. The level of photosystem (PS) II was equivalent to that of PS I in Bryopsis maxima but lower than that of PS I in Ulva pertusa. Analysis of Q(A) photoreduction and P-700 photo-oxidation with green light revealed that >50% of PS II centres are non-functional in electron transport. Thus, the ratio of the functional PS II to PS I is only 0.46 in Bryopsis maxima and 0.35 in Ulva pertusa. Light-response curves of electron transport also provided evidence that PS I had a larger light-harvesting capacity than did the functional PS II. Thus, there was a large imbalance in the light absorption between the two photosystems, with PS I showing a larger total light-harvesting capacity than PS II. Furthermore, as judged from the measurements of low temperature fluorescence spectra, the light energy absorbed by Chl b was efficiently transferred to PS I in both algae. Based on the above results, it is hypothesized that marine green algae require a higher ATP:NADPH ratio than do terrestrial plants to grow and survive under a coastal environment. PMID:15797939

Yamazaki, Jun-Ya; Suzuki, Takahisa; Maruta, Emiko; Kamimura, Yasumaro

2005-06-01

104

Comparison of sediment grain size characteristics on nourished and un-nourished estuarine beaches and impacts on horseshoe crab habitat, Delaware Bay, New Jersey  

USGS Publications Warehouse

This study was undertaken to determine whether nourished and un-nourished estuarine beaches have conspicuous differences in sediment size and sorting that could affect their value as habitat for horseshoe crabs. Comparisons are made of beach profiles and sediment samples gathered at 0.15 m and 0.30 m depths on the backshore, at spring tide elevation, neap tide elevation, and the lower foreshore on 5 un-nourished and 3 nourished beaches in Delaware Bay, where tidal range is <2.0 m. The backshore is at least 0.5 m higher on the recently nourished beaches than on a nearby un-nourished beach reworked by storm waves. Nourishing these beaches to elevations higher than natural overwash heights will restrict natural evolution of the upper beach. Sediments at spring tide elevation on un-nourished sites average 0.72 mm in diameter at 0.15 m depth and 0.67 mm at 0.30 m depth.The similarity in size implies a relatively deep active layer in the zone of maximum cut and fill associated with cyclic profile change during low frequency, high magnitude storms. Sedimentary changes at neap tide elevation may be influenced more by depth of activation by waves than by cycles of deposition and erosion. Sediment at 0.15 m depth at spring and neap locations on the foreshore of nourished beaches is finer (0.51 mm) and better sorted (0.82 phi) than at 0.30 m depth (0.91 mm, 1.38 phi), implying that waves have not reworked the deeper sediments. Differences in sediment characteristics at depth may persist on eroding nourished beaches, where unreworked fill is close to the surface. Sediment texture influences horseshoe crab egg viability and development. Lower rates of water movement through the foreshore and greater thickness of the capillary fringe on nourished sites suggests that greater moisture retention will occur where horseshoe crabs bury eggs and may provide more favorable conditions for egg development, but the depth of these conditions will not be great on a recently nourished beach. ?? 2005 Gebru??der Borntraeger.

Jackson, N.L.; Smith, D.R.; Nordstrom, K.F.

2005-01-01

105

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

PubMed Central

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

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

2014-01-01

106

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

PubMed

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

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

2014-01-01

107

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.

108

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

Microsoft Academic Search

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

Bram Vanschoenwinkel; Maitland Seaman; Luc Brendonck

2010-01-01

109

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

110

Effects of air temperature, air movement and artificial rain on the heat production of brushtail possums (Trichosurus vulpecula): an exploratory study.  

PubMed

Two groups of six mature brushtail possums (Trichosurus vulpeculu) were housed in two respiration chambers, and their heat production, whole body conductance and lower critical temperatures were measured under a variety of simulated weather patterns. The possums were subjected to ambient temperatures of 30, 20 and 3 degrees C. At 20 and 3 degrees C, the animals were exposed to near still air and light winds (wind speed 0.8 and 6.7 km/h), both with, and without, simulated rain every 8 hours. The lower critical temperature in near still air lies between 7 and 10 degrees C. This temperature increases by about 2, 6 and 8 degrees C respectively for a wind velocity of 6.7 km/h, simulated rain and a combination of the two factors. Weather in New Zealand, especially in the cooler part of the year, will often produce conditions below the lower critical temperature of the thermoneutral zone of possums. This will necessitate significant increases in metabolic rate and hence food consumption or mobilisation of body fat reserves, which if not sustainable will result in the death of possums. Field studies have shown that this is often the case in the wild. It is proposed that this stress may be sufficient to decrease the resistance (especially cell-mediated immunity) of some possums and allow acceleration of the disease process in those infected with Mycobacterium bovis. PMID:16031874

van den Oord, Q G; van Wijk, E J; Lugton, I W; Morris, R S; Holmes, C W

1995-12-01

111

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

PubMed

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

112

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

PubMed Central

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

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

2007-01-01

113

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

114

Considerations of a habitat design  

NASA Astrophysics Data System (ADS)

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

115

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

116

Mars habitat  

NASA Technical Reports Server (NTRS)

The College of Engineering & Architecture at Prairie View A&M University has been participating in the NASA/USRA Advanced Design Program since 1986. The interdisciplinary nature of the program allowed the involvement of students and faculty throughout the College of Engineering & Architecture for the last five years. The research goal for the 1990-1991 year is to design a human habitat on Mars that can be used as a permanent base for 20 crew members. The research is being conducted by undergraduate students from the Department of Architecture.

1991-01-01

117

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

Microsoft Academic Search

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

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

118

Habitat Demonstration Unit - Deep Space Habitat Configuration  

NASA Video Gallery

This animated video shows the process of transporting, assembling and testing the Habitat Demonstration Unit - Deep Space Habitat (HDU DSH) configuration, which will be deployed during the 2011 Des...

119

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

120

QUANTIFYING STREAM STRUCTURAL PHYSICAL HABITAT ATTRIBUTES USING LIDAR AND HYPERSPECTRAL IMAGERY  

EPA Science Inventory

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

121

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

EPA Science Inventory

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

122

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

EPA Science Inventory

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

123

Habitat Associated with Barred Owl (Strix varia) Locations in Southeastern Manitoba: A Review of a Habitat Model  

Microsoft Academic Search

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

James R. Duncan; Amy E. Kearns

124

Temporal transferability of wildlife habitat models: implications for habitat  

E-print Network

modelling constitutes a suitable tool for characterizing wildlife habitat and monitoring its temporal transferability, MODIS, remote sensing, species distribution model, WDRVI, wildlife habitat monitoring, WolongORIGINAL ARTICLE Temporal transferability of wildlife habitat models: implications for habitat

125

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.

126

HABITAT ASSESSMENT METHODS  

EPA Science Inventory

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

127

Quantitative recommendations for amphibian terrestrial habitat conservation derived from habitat selection behavior.  

PubMed

Conservation scientists have noted that conservation managers rarely use scientific information when making decisions. One of the reasons why managers rarely use scientific information may be that conservation scientists rarely provide their knowledge in a way that can directly be used by conservation practitioners. Here we show how quantitative recommendations for conservation can be derived. Previous research on terrestrial habitat selection behavior of toads (Bufo bufo and Bufo viridis) showed that wood deposits are a key resource in the terrestrial habitat. We used habitat-dependence analysis to estimate the amount of this key resource, wood deposits, that individual toads require. Based on these estimates we then quantify the requirements for wood deposits for a population. Additionally, we quantified the area that a population requires. Although wood deposits vary strongly in size, we found little evidence for size preferences: only one species preferred smallest sizes of wood deposits. We report all the estimates in a way that can be directly used by conservation managers. Habitat-dependence analysis is a simple and useful tool to quantify habitat requirements. Provisioning of wood deposits may improve the quality of terrestrial habitat for amphibians. Thereby, managers may increase the carrying capacity of terrestrial habitats and support elevated population densities. PMID:22073643

Indermaur, Lukas; Schmidt, Benedikt R

2011-10-01

128

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

129

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.

Zagarella, Jennifer

2012-07-31

130

Wildlife Habitat of Maine  

Microsoft Academic Search

The Wildlife Habitat of Maine map was created using data from the Maine Office of GIS and the United States National Atlas. The map shows the land cover characteristics of Maine, including human development and major roads. The most suitable wildlife habitat can be attributed to the areas with the most suitable land cover and the least human development. An

Wendy Sicard

2005-01-01

131

Wildlife Habitat Evaluation Handbook.  

ERIC Educational Resources Information Center

The National 4-H Wildlife Invitational is a competitive event to teach youth about the fundamentals of wildlife management. Youth learn that management for wildlife means management of wildlife habitat and providing for the needs of wildlife. This handbook provides information about wildlife habitat management concepts in both urban and rural…

Neilson, Edward L., Jr.; Benson, Delwin E.

132

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

133

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

PubMed Central

Background Larval control is of paramount importance in the reduction of malaria vector abundance and subsequent disease transmission reduction. Understanding larval habitat succession and its ecology in different land use managements and cropping systems can give an insight for effective larval source management practices. This study investigated larval habitat succession and ecological parameters which influence larval abundance in malaria epidemic prone areas of western Kenya. Methods and Findings A total of 51 aquatic habitats positive for anopheline larvae were surveyed and visited once a week for a period of 85 weeks in succession. Habitats were selected and identified. Mosquito larval species, physico-chemical parameters, habitat size, grass cover, crop cycle and distance to nearest house were recorded. Polymerase chain reaction revealed that An. gambiae s.l was the most dominant vector species comprised of An.gambiae s.s (77.60%) and An.arabiensis (18.34%), the remaining 4.06% had no amplification by polymerase chain reaction. Physico-chemical parameters and habitat size significantly influenced abundance of An. gambiae s.s (P?=?0.024) and An. arabiensis (P?=?0.002) larvae. Further, larval species abundance was influenced by crop cycle (P?0.001), grass cover (P?0.001), while distance to nearest houses significantly influenced the abundance of mosquito species larvae (r?=?0.920;P?0.001). The number of predator species influenced mosquito larval abundance in different habitat types. Crop weeding significantly influenced with the abundance of An.gambiae s.l (P?0.001) when preceded with fertilizer application. Significantly higher anopheline larval abundance was recorded in habitats in pasture compared to farmland (P?=?0.002). When habitat stability and habitat types were considered, hoof print were the most productive followed by disused goldmines. Conclusion These findings suggest that implementation of effective larval control programme should be targeted with larval habitats succession information when larval habitats are fewer and manageable. Crop cycles and distance from habitats to household should be considered as effective information in planning larval control. PMID:23272215

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

2012-01-01

134

Inflatable Habitats Technology Development  

NASA Technical Reports Server (NTRS)

For many years inflatable structures have been theorized for use as satellite dishes, deployable arrays and human habitats. They fall into human-rated and non-human rated structures. As such the structural design requirements and safety redundancy are much different. This paper will discuss the Habitat and Surface Construction Technology that would support the development of Mars greenhouses as well as habitats. This paper will briefly describe the ISS TransHab architectural design and structural testing for the proposed as a habitation module for the International Space Station. It will also discuss inflatable greenhouse design considerations and examples.

Kennedy, Kriss J.

2000-01-01

135

Sensitivity analysis of physiological factors in space habitat design  

NASA Technical Reports Server (NTRS)

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

Billingham, J.

1982-01-01

136

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

PubMed

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

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

2012-09-01

137

Modeling habitat suitability for Greater Rheas based on satellite image texture.  

PubMed

Many wild species are affected by human activities occurring at broad spatial scales. For instance, in South America, habitat loss threatens Greater Rhea (Rhea americana) populations, making it important to model and map their habitat to better target conservation efforts. Spatially explicit habitat modeling is a powerful approach to understand and predict species occurrence and abundance. One problem with this approach is that commonly used land cover classifications do not capture the variability within a given land cover class that might constitute important habitat attribute information. Texture measures derived from remote sensing images quantify the variability in habitat features among and within habitat types; hence they are potentially a powerful tool to assess species-habitat relationships. Our goal was to explore the utility of texture measures for habitat modeling and to develop a habitat suitability map for Greater Rheas at the home range level in grasslands of Argentina. Greater Rhea group size obtained from aerial surveys was regressed against distance to roads, houses, and water, and land cover class abundance (dicotyledons, crops, grassland, forest, and bare soil), normalized difference vegetation index (NDVI), and selected first- and second-order texture measures derived from Landsat Thematic Mapper (TM) imagery. Among univariate models, Rhea group size was most strongly positively correlated with texture variables derived from near infrared reflectance measurement (TM band 4). The best multiple regression models explained 78% of the variability in Greater Rhea group size. Our results suggest that texture variables captured habitat heterogeneity that the conventional land cover classification did not detect. We used Greater Rhea group size as an indicator of habitat suitability; we categorized model output into different habitat quality classes. Only 16% of the study area represented high-quality habitat for Greater Rheas (group size > or =15). Our results stress the potential of image texture to capture within-habitat variability in habitat assessments, and the necessity to preserve the remaining natural habitat for Greater Rheas. PMID:19263890

Bellis, Laura M; Pidgeon, Anna M; Radeloff, Volker C; St-Louis, Véronique; Navarro, Joaquín L; Martella, Mónica B

2008-12-01

138

Habitat-Specific Differences in Mercury Concentration in a Top Predator from a Shallow Lake  

Microsoft Academic Search

We conducted a survey of mercury contamination in largemouth bass Micropterus salmoides from Caddo Lake, Texas, and found that fish collected from forested wetland habitat had higher concentrations of mercury than those collected from open-water habitat. Habitat-specific differences in largemouth bass size, age, absolute growth rate, trophic position (based on ?N), and horizontal food web position (based on ?C), characteristics

Matthew M. Chumchal; Ray W. Drenner; Brian Fry; K. David Hambright; Leo W. Newland

2008-01-01

139

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.

140

Vacant Habitats in the Universe  

Microsoft Academic Search

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

Charles S. Cockell

2010-01-01

141

Habitat Suitability Index Models: Muskellunge  

USGS Publications Warehouse

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

Cook, Mark F.; Solomon, R. Charles

1987-01-01

142

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

143

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

144

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

145

Habitat type and ambient temperature contribute to bill morphology.  

PubMed

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

Luther, David; Greenberg, Russell

2014-03-01

146

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

147

Comparing quality of estuarine and nearshore intertidal habitats for Carcinus maenas  

NASA Astrophysics Data System (ADS)

Estuarine and nearshore marine areas are vital habitats for several fish and benthic invertebrates. The shore crab Carcinus maenas (Crustacea: Brachyura: Portunidae) inhabits a variety of coastal, estuarine and lagoon habitats. At low tide, habitat structural complexity may be most important for crabs in the intertidal, providing refuge from predation and desiccation. The quality of different vegetated and nonvegetated estuarine and rocky shore habitats in SW Portugal and SW England was evaluated for intertidal C. maenas populations. We estimated population density, size-structure, and potential growth (RNA/DNA ratios) to investigate habitat quality. Vegetated estuarine habitats supported higher crab densities, than nonvegetated estuarine and rocky shore habitats. Investigation of population size-structure revealed that all habitats seem important recruitment and nursery areas although estuarine habitats in SW Portugal appeared to support higher densities of new recruits than equivalent habitats in SW England. Significant variation was found in RNA/DNA ratios among habitats. Ratios were highest in the rocky shore suggesting a high quality habitat where growth potential is high. We speculate that competition from other top-predators ( Pachygrapsus spp.) rather than low habitat quality may limit the occurrence of C. maenas in intertidal rocky shore habitats in SW Portugal. In estuarine environments RNA/DNA ratios were significantly higher in the vegetated than in the nonvegetated estuarine habitats in SW Portugal but not in SW England, suggesting geographic differences in the extent to which highly structure habitats represent high quality. Our results challenge the current paradigm that structured habitats are necessarily those of higher quality for C. maenas.

Amaral, Valter; Cabral, Henrique N.; Jenkins, Stuart; Hawkins, Stephen; Paula, José

2009-06-01

148

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

149

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...

150

POTENTAIL HABITAT MOUNTAIN PLOVERS  

E-print Network

POTENTAIL HABITAT FOR MOUNTAIN PLOVERS ON COLORADO SPRINGS UTILITIES PROPERTY A Report to Colorado Delivery Fort Collins, Colorado 80523-8002 #12;INTRODUCTION The Mountain Plover (Charadrius montanus with the USFWS. According to Knopf and Miller (1994), "the Continental population of Mountain Plovers has

151

Modeling sensitive elasmobranch habitats  

NASA Astrophysics Data System (ADS)

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

Pennino, M. Grazia; Muñoz, Facundo; Conesa, David; López-Qu?lez, Antonio; Bellido, José Mar?a

2013-10-01

152

Habitat Suitability Index Models: Osprey,  

National Technical Information Service (NTIS)

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the osprey (Pandion haliaetus). The model consolidates habitat use information into a framework appropriate for field application, and is scale...

S. L. Vana-Miller

1987-01-01

153

System for assessing habitat value  

US Patent & Trademark Office Database

A system for quantifying or assigning values to habitats and/or species occurring within a geographic site. In one implementation, for example, a baseline habitat value is assigned to a geographic site prior to the performance of a proposed activity impacting the site, such as development or construction. The baseline habitat value is based at least in part on the specific types of habitats found in the site, the number of species found in the site, and the key ecological functions associated with each species. The baseline habitat value can be adjusted to account for the potential presence of invasive plant species within the site. A future habitat value for the site following the performance of the activity also can be determined. A debit value associated with the proposed activity can be determined by subtracting the future habitat value from the baseline habitat value.

2010-03-23

154

Understanding the Habitat Needs of the Declining Western Yellow-Billed Cuckoo  

USGS Publications Warehouse

The western yellow-billed cuckoo, once common along the streams and rivers of the American West, is now a candidate for protection under the Endangered Species Act. Most of the remaining breeding pairs are found in Arizona, California, and New Mexico. Research to understand the cuckoos' habitat needs by U.S. Geological Survey (USGS) and Northern Arizona University scientists has shown that cuckoos in Arizona prefer breeding habitat dominated by native tree species, especially cottonwood-willow habitat bordered by mesquite bosque habitat. This research also revealed that the size of habitat patches matters - breeding cuckoos were found only in large, continuous areas of riparian habitat. These findings and the development of spatially explicit habitat models by USGS scientists will help resource managers conserve and manage riparian habitats needed to ensure the survival of the western yellow-billed cuckoo.

Johnson, Matthew J.

2009-01-01

155

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

156

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

157

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

158

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

159

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

160

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

161

Habitats of Life  

NASA Astrophysics Data System (ADS)

There are four principal habitats in which life may exist - the surface of a planetary body, its subsurface, its atmosphere and space. From our own experience we know that life does exist on the surface of a planet, in its subsurface, and transiently at least in the atmosphere. Where it is present, it exists in a surprising diversity and in a variety of microhabitats, from deep caverns (Hose et al. 2000, Melim et al. 2001) to hydrothermal fluids and hot springs of various chemistries (Jannasch 1995, Rzonca and Schulze-Makuch 2002), to the frozen deserts of Antarctica (Friedmann 1982, Sun and Friedmann 1999). In this chapter we will elaborate on the principal habitats, the constraints they impose on life, and the possibilities they provide.

Dirk, Schulze-Makuch; Irwin, Louis N.

162

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

163

Consistency of temporal and habitat-related differences among assemblages of fish in coastal lagoons  

NASA Astrophysics Data System (ADS)

The consistency of habitat-related differences in coastal lagoon fish assemblages was assessed across different spatial and temporal scales. Multimesh gillnets were used to sample assemblages of fish on a monthly basis for 1-year in three habitats (shallow seagrass, shallow bare and deep substrata) at two locations (>1 km apart), in each of two coastal lagoons (approximately 500 km apart), in southeastern Australia. A total of 48 species was sampled with 34 species occurring in both lagoons and in all three habitats; species caught in only one lagoon or habitat occurred in low numbers. Ten species dominated assemblages and accounted for more than 83% of all individuals sampled. In both lagoons, assemblages in the deep habitat consistently differed to those in the shallow strata (regardless of habitat). Several species were caught more frequently or in larger numbers in the deep habitat. Assemblages in the two shallow habitats did not differ consistently and were dominated by the same species and sizes of fish, possibly due to habitat heterogeneity and the scale and method of sampling. Within each lagoon, very few between location differences in assemblages within each habitat were observed. Consistent differences in assemblages were detected between lagoons for the shallow bare and deep habitats, indicating there were some intrinsic differences in ichthyofauna between lagoons. Assemblages in spring differed to those in summer, which differed to those in winter for the shallow bare habitat in both lagoons, and the deep habitat in only one lagoon. Fish-habitat relationships are complex and differences in the fish fauna between habitats were often temporally inconsistent. This study highlights the need for greater testing of habitat relationships in space and time to assess the generality of observations and to identify the processes responsible for structuring assemblages.

Gray, Charles A.; Rotherham, Douglas; Johnson, Daniel D.

2011-12-01

164

Fishing in a Shallow Lake: Exploring a Classic Fishery Model in a Habitat with Shallow Lake Dynamics  

Microsoft Academic Search

Renewable resources such as fish exist within habitats. Harvesting activities may directly impact the habitat, beyond the\\u000a influence caused by changing the balance between species. When harvesting activities impact stock size and habitat health\\u000a in different ways, both states must be explicitly considered. A classic fisheries model is embedded in a habitat that exhibits\\u000a shallow lake dynamics, where carrying capacity

Johannus A. Janmaat

2012-01-01

165

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

166

Vacant Habitats in the Universe  

NASA Astrophysics Data System (ADS)

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.

Cockell, Charles S.

2010-12-01

167

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

168

Habitat Conservation Planning Support  

NSDL National Science Digital Library

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

169

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

170

Partial gravity habitat study  

NASA Technical Reports Server (NTRS)

The purpose of this study is to investigate comprehensive design requirements associated with designing habitats for humans in a partial gravity environment, then to apply them to a lunar base design. Other potential sites for application include planetary surfaces such as Mars, variable-gravity research facilities, and a rotating spacecraft. Design requirements for partial gravity environments include locomotion changes in less than normal earth gravity; facility design issues, such as interior configuration, module diameter, and geometry; and volumetric requirements based on the previous as well as psychological issues involved in prolonged isolation. For application to a lunar base, it is necessary to study the exterior architecture and configuration to insure optimum circulation patterns while providing dual egress; radiation protection issues are addressed to provide a safe and healthy environment for the crew; and finally, the overall site is studied to locate all associated facilities in context with the habitat. Mission planning is not the purpose of this study; therefore, a Lockheed scenario is used as an outline for the lunar base application, which is then modified to meet the project needs. The goal of this report is to formulate facts on human reactions to partial gravity environments, derive design requirements based on these facts, and apply the requirements to a partial gravity situation which, for this study, was a lunar base.

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

1989-01-01

171

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

172

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

173

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.

174

Wildlife habitat analysis – a multidimensional habitat management model  

Microsoft Academic Search

In intensively cultivated landscapes, the effects of land use – changing habitat quality and habitat availability - on wildlife populations are of major importance for wildlife management. Populations of some species reach high densities, grow rapidly, and can therefore cause damage to tree regeneration in forests; chamois (Rupicapra rupicapra) is an example. Other species, like capercaillie (Tetrao urogallus), suffer from

Rudi Suchant; Rainer Baritz; Vero Braunisch

2003-01-01

175

Optimizing wildlife habitat mitigation with a habitat defragmentation algorithm  

Microsoft Academic Search

Habitat fragmentation is being increasingly recognized as a serious problem for a variety of wildlife species. While it is possible to approximately determine by eye where on a map a habitat alteration could be used to decrease fragmentation, this is a slow and imprecise method that is impractical for large maps. An algorithm is presented that automates this task. The

Craig Loehle

1999-01-01

176

Modeling Habitat Split: Landscape and Life History Traits Determine Amphibian Extinction Thresholds  

PubMed Central

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

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

2013-01-01

177

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

PubMed

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

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

2013-01-01

178

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

179

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

180

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

181

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

182

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

183

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

Microsoft Academic Search

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

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

1998-01-01

184

PRIMARY RESEARCH PAPER The influence of littoral zone coarse woody habitat on home  

E-print Network

PRIMARY RESEARCH PAPER The influence of littoral zone coarse woody habitat on home range size: 22 November 2008 / Published online: 10 December 2008 Ã? Springer Science+Business Media B.V. 2008 Abstract Coarse woody habitat (CWH) may be a critical feature of lakes that influences fish distribu- tions

185

QUANTIFYING THE SENSITIVITY OF ARCTIC MARINE MAMMALS TO CLIMATE-INDUCED HABITAT CHANGE  

Microsoft Academic Search

We review seven Arctic and four subarctic marine mammal species, their habitat requirements, and evidence for biological and demographic responses to climate change. We then describe a pan-Arctic quantitative index of species sensitivity to climate change based on population size, geographic range, habitat specificity, diet diversity, migration, site fidelity, sensitivity to changes in sea ice, sensitivity to changes in the

Kristin L. Laidre; Ian Stirling; Lloyd F. Lowry; Øystein Wiig; Mads Peter Heide-Jørgensen; Steven H. Ferguson

2008-01-01

186

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

187

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

Microsoft Academic Search

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

Philip Roni

2002-01-01

188

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...

189

Stream habitat hydraulics: interannual variability in three reaches of Catamaran Brook, New Brunswick  

Microsoft Academic Search

The hydraulic habitat of 12 sites in a small salmon stream in central New Brunswick was investigated between 1992 and 1995 to determine patterns of habitat (substrate) stability between and within reaches. Stability was evaluated by measuring particle size distribution in replicated erosional and depositional sites in each reach and calculating the proportion of the bed predicted to be in

Donna J. Giberson; Daniel Caissie

1998-01-01

190

Largemouth Bass Abundance and Angler Catch Rates following a Habitat Enhancement Project at Lake Kissimmee, Florida  

Microsoft Academic Search

A habitat enhancement project was conducted at Lake Kissimmee, Florida, during 1995-1996 to improve fish habitat and remove dense inshore vegetation caused by stabilized water levels. We evaluated abundance of age-1 (<250 mm total length (TL)) and adult (fish at least 356 mm TL and all sizes of fish caught by anglers) largemouth bass Micropterus salmoides before and after the

Mike S. Allen; Kimberly I. Tugend; Marty J. Mann

2003-01-01

191

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

192

Annual and seasonal habitat use of Columbian black-tailed deer in urban Vancouver, Washington  

Microsoft Academic Search

We investigated habitat use of Columbian black-tailed deer in urban Vancouver, Clark County, Washington, at 3 spatial scales: (1) placement of the annual home range within the landscape mosaic, (2) annual and seasonal locations of deer within the annual home range, and (3) short-term use of critical habitats (fawning areas) within seasonal ranges. Annual home range sizes of deer were

Louis C. Bender; David P. Anderson; Jeffrey C. Lewis

2004-01-01

193

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

194

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

195

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

196

Habitat Suitability Index Models: Yellow Perch  

USGS Publications Warehouse

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

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

1983-01-01

197

Types of habitat in the Universe  

NASA Astrophysics Data System (ADS)

From a biological point of view, all environments in the Universe can be categorized into one of three types: uninhabitable, uninhabited habitat or inhabited habitat. This paper describes and defines different habitat types in the Universe with a special focus on environments not usually encountered on the Earth, but which might be common on other planetary bodies. They include uninhabited habitats, subtypes of which are sterile habitats and organic-free habitats. Examples of the different types of environments are provided with reference to the Eyjafjallajökull, Iceland. These habitat types are used to identify testable hypotheses on the abundance of different habitats and the distribution of life in the Universe.

Cockell, Charles S.

2014-04-01

198

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

199

Avian habitat relationships in pinyon-juniper woodland  

USGS Publications Warehouse

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

Sedgwick, James A.

1987-01-01

200

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

201

Role of Tidal Saltwater Habitats for Juvenile Salmonids  

E-print Network

­ Connect upstream spawning and rearing areas to ocean habitat ·Transition to saltwater #12;2002 2003 2004Fingerlings 6090mm Subyearlings/Yearlings 100200 mm Size seen in the ocean, composed of juveniles using fry, fingerling, subyearling, and yearling strategy Fry ­ distributes throughout the river, estuary and ocean

202

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

203

Habitat selection and productivity of least terns on the lower Platte River, Nebraska  

USGS Publications Warehouse

Least terns (Sterna antillarum) were studied on the lower Platte River, Nebraska, where this endangered population nests on natural sandbar habitat and on sandpit sites created by gravel dredging adjacent to the river. Theoretically terns should select habitats according to habitat suitability. However, the introduction of sandpits and conversion of tallgrass prairies along the river banks to agriculture, residential, and wooded areas may have affected terns' abilities to distinguish suitable habitat or the suitability of nesting habitats in general. I examined habitat selection and productivity of least terns to determine if terns selected habitat according to suitability (as indicated by productivity), what factors affected habitat selection and productivity, and if estimated productivity could support this population. Available habitats of both types were characterized and quantified using aerial videography (1989-90), and habitat use was assessed from census data (1987-90). Productivity of adults and causes and correlates of egg and chick mortality were estimated (1987-90). Population trend was assessed with a deterministic model using my estimates of productivity and a range of survival estimates for Laridae reported in the literature. Terns tended to use river sites with large midstream sandbars and a wide channel, and large sandpit sites with large surface areas of water relative to unused sites on both habitats. Number of sites and area of sand available were estimated using discriminant function analysis of variables quantified from video scenes of both habitats. Terns apparently did not use all potentially available sandbar and sandpit sites because discriminant function factor scores for used and unused sites overlapped broadly for both habitats. Terns did not prefer 1 habitat over the other. Although proportions of available sites used were greater on sandpits than on the river, proportions of available sand used did not differ between habitats. Proportion of terns using each habitat was similar to proportion of available sand on each habitat. The distribution of nest initiation dates and rates of colony-site turnover also were similar on both habitats. Productivity did not differ between habitats but varied significantly among sites. Nest success, fledging success, and fledglings per pair averaged 0.54, 0.28, and 0.47, respectively. Key factor analysis revealed that chick survival had a greater influence on production of fledglings (on both sandbars and sandpits) than did failure to produce a maximum clutch size or egg mortality. Most egg mortality was caused by predation on sandpits and by flooding on sandbars. Predation was suspected as the major cause of loss for chicks on both habitats. Path analysis revealed no strong or consistent correlations among mortality, numbers of nests and chicks, track trails of intruders into colonies, and habitat variables at colonies on either habitat. Theoretically, terns should not prefer a habitat when habitats are equally suitable if terns have had time to respond to habitat changes. Although sandbars and sandpits appeared equally suitable and terns did not prefer either habitat, local productivity will not support this population unless annual postfledging survival is higher than current estimates for the species. Population trend estimated with fledglings per pair = 0.50 was negative for all but the highest (ca 0.90) rates of annual postfledging survival. Furthermore, deterministic models like the one used in this study overstimate trend. Productivity insufficient to support the local population, in spite of habitat use that reflects habitat suitability, could be due to increased predation caused by habitat alteration adjacent to the river that may have changed the predator community. Alternatively, terns in this area could persist in spite of prevailing low productivity because they are relatively long-lived birds, if highly productive years occasionally occur or if this population is augmented by immigrants from elsewhere.

Kirsch, Eileen M.

1996-01-01

204

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

205

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...

206

Habitat-specific foraging of prothonotary warblers: Deducing habitat quality  

USGS Publications Warehouse

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

Lyons, J.E.

2005-01-01

207

Impact of China's May 12 earthquake on Giant Panda habitat in Wenchuan County  

NASA Astrophysics Data System (ADS)

The Minshan and Qionglai mountains, the major distribution range of the Giant Panda (Ailuropoda melanoleuca), was struck by the Wenchuan earthquake. In this study, we evaluated the impact of the earthquake and subsequent geo-disasters on the Giant Panda and its habitat using Wenchuan county (where the epicenter was located) as a case study. Habitat characteristics before and after the earthquake were analyzed based on TM images taken pre and post-earthquake and previous research in this region. Results showed that about 252.0 km2 of panda habitat was lost in Wenchuan County after the earthquake, which accounted for 13.9% of the total habitat in this county. Regions with high earthquake intensity, low elevation, steep slope, and near river had a higher proportion of habitat loss than in other regions. In addition to habitat loss, the earthquake and its resulting geo-disasters also caused habitat fragmentation. After the earthquake, the number of habitat patches increased by a factor of 2 and mean patch size was only 28.3% of pre-earthquake conditions. Habitat restoration and corridor reparation along Road 303 are necessary for facilitating panda's migration between isolated patches. It is necessary to take some measures including relocation of residents and earthquake compensation to decrease the impact of reconstruction on the Giant Panda and its habitat.

Xu, Weihua; Dong, Rencai; Wang, Xuezhi; Ouyang, Zhiyun; Li, Zhiqi; Xiao, Yi; Zhang, Jindong

2009-05-01

208

75 FR 38441 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Santa Ana Sucker  

Federal Register 2010, 2011, 2012, 2013

...risk due to its small population sizes and specifically threatened by habitat destruction, degradation, and fragmentation; dewatering; reductions in water quality; fire; recreational activities; and competition and predation from nonnative species...

2010-07-02

209

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

210

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

PubMed Central

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

Smoothey, Amy F.

2013-01-01

211

Habitat-associations of turban snails on intertidal and subtidal rocky reefs.  

PubMed

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

Smoothey, Amy F

2013-01-01

212

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

PubMed

Habitat classification models (HCMs) are invaluable tools for species conservation, land-use planning, reserve design, and metapopulation assessments, particularly at broad spatial scales. However, species occurrence data are often lacking and typically limited to presence points at broad scales. This lack of absence data precludes the use of many statistical techniques for HCMs. One option is to generate pseudo-absence points so that the many available statistical modeling tools can bb used. Traditional techniques generate pseudo-absence points at random across broadly defined species ranges, often failing to include biological knowledge concerning the species-habitat relationship. We incorporated biological knowledge of the species-habitat relationship into pseudo-absence points by creating habitat envelopes that constrain the region from which points were randomly selected. We define a habitat envelope as an ecological representation of a species, or species feature's (e.g., nest) observed distribution (i.e., realized niche) based on a single attribute, or the spatial intersection of multiple attributes. We created HCMs for Northern Goshawk (Accipiter gentilis atricapillus) nest habitat during the breeding season across Utah forests with extant nest presence points and ecologically based pseudo-absence points using logistic regression. Predictor variables were derived from 30-m USDA Landfire and 250-m Forest Inventory and Analysis (FIA) map products. These habitat-envelope-based models were then compared to null envelope models which use traditional practices for generating pseudo-absences. Models were assessed for fit and predictive capability using metrics such as kappa, threshold-independent receiver operating characteristic (ROC) plots, adjusted deviance (D(adj)2), and cross-validation, and were also assessed for ecological relevance. For all cases, habitat envelope-based models outperformed null envelope models and were more ecologically relevant, suggesting that incorporating biological knowledge into pseudo-absence point generation is a powerful tool for species habitat assessments. Furthermore, given some a priori knowledge of the species-habitat relationship, ecologically based pseudo-absence points can be applied to any species, ecosystem, data resolution, and spatial extent. PMID:17913135

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

2007-09-01

213

Toward an Identification of Resources Influencing Habitat Use in a Multi-Specific Context  

PubMed Central

Interactions between animal behaviour and the environment are both shaping observed habitat use. Despite the importance of inter-specific interactions on the habitat use performed by individuals, most previous analyses have focused on case studies of single species. By focusing on two sympatric populations of large herbivores with contrasting body size, we went one step beyond by studying variation in home range size and identifying the factors involved in such variation, to define how habitat features such as resource heterogeneity, resource quality, and openness created by hurricane or forest managers, and constraints may influence habitat use at the individual level. We found a large variability among individual's home range size in both species, particularly in summer. Season appeared as the most important factor accounting for observed variation in home range size. Regarding habitat features, we found that (i) the proportion of area damaged by the hurricane was the only habitat component that inversely influenced roe deer home range size, (ii) this habitat type also influenced both diurnal and nocturnal red deer home range sizes, (iii) home range size of red deer during the day was inversely influenced by the biomass of their preferred plants, as were both diurnal and nocturnal core areas of the red deer home range, and (iv) we do not find any effect of resource heterogeneity on home range size in any case. Our results suggest that a particular habitat type (i.e. areas damaged by hurricane) can be used by individuals of sympatric species because it brings both protected and dietary resources. Thus, it is necessary to maintain the openness of these areas and to keep animal density quite low as observed in these hunted populations to limit competition between these sympatric populations of herbivores. PMID:22216164

Richard, Emmanuelle; Said, Sonia; Hamann, Jean-Luc; Gaillard, Jean-Michel

2011-01-01

214

Geopressured habitat: A literature review  

SciTech Connect

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

Negus-de Wys, Jane

1992-09-01

215

SHORELINE, LAKE, AND ESTUARY SCALE HABITAT RESEARCH  

EPA Science Inventory

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

216

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

SciTech Connect

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

Bumgarner, Joseph D.

1999-03-01

217

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

218

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

E-print Network

Accessible habitat: an improved measure of the effects of habitat loss and roads on wildlife: Accessible habitat: an improved measure of the effects of habitat loss and roads on wildlife populations). In addition, the replacement of habitat with certain matrix cover types can create barriers or filters

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: 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

221

Species Interactions Among Larval Mosquitoes: Context Dependence Across Habitat Gradients  

PubMed Central

Biotic interactions involving mosquito larvae are context dependent, with effects of interactions on populations altered by ecological conditions. Relative impacts of competition and predation change across a gradient of habitat size and permanence. Asymmetrical competition is common and ecological context changes competitive advantage, potentially facilitating landscape-level coexistence of competitors. Predator effects on mosquito populations sometimes depend on habitat structure and on emergent effects of multiple predators, particularly interference among predators. Nonlethal effects of predators on mosquito oviposition, foraging, and life history are common, and their consequences for populations and for mosquito-borne disease are poorly understood. Context-dependent beneficial effects of detritus shredders on mosquitoes occur in container habitats, but these interactions appear to involve more than simple resource modification by shredders. Investigations of context-dependent interactions among mosquito larvae will yield greater understanding of mosquito population dynamics and provide useful model systems for testing theories of context dependence in communities. PMID:19067629

Juliano, Steven A.

2009-01-01

222

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

223

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

224

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

USGS Publications Warehouse

Although considerable information exists on habitat use by stream salmonids, only a small portion has quantitatively examined diurnal and nocturnal habitat variation. We examined diel variation in habitat use by age-0 and age-1+ brook trout (Salvelinus fontinalis) during summer and autumn in a headwater stream in northern Pennsylvania. Habitat variables measured included cover, depth, substrate, and velocity. The most pronounced diel variation occurred in the use of cover during both seasons. Both age-0 brook trout and age-1+ trout were associated with less cover at night. Age-0 brook trout occupied swifter water during the day than at night during both seasons, but the difference was not significant. Increased cover, depth, and substrate size governed the habitat of age-1+ brook trout. Our findings support the need for a better understanding of diel differences in habitat use of stream salmonids when considering habitat enhancement and protection.

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

2011-01-01

225

Multiple foundation species shape benthic habitat islands.  

PubMed

Pattern generation by foundation species (FS) is a primary structuring agent in marine and terrestrial communities. Prior research, focused on single-species or guild-dominated habitats, stressed the role of facilitation in maintaining community structure. However, many habitats are developed by multiple FS from different guilds. Competition between these FS may provide an additional agent potentially responsible for spatial and temporal patterns. In the White Sea, epibenthic patches formed by barnacles (Balanus crenatus) and solitary ascidians (mainly Styela spp. and Molgula spp.) on small stones and empty bivalve shells (mainly Serripes groenlandicus) produce microhabitats for different sessile taxa. We hypothesized that: (1) several FS would provide habitats for most of other species in the community; (2) different FS promote different assemblages of sessile organisms; (3) the interplay of facilitation and competition best explains observed patterns of abundance and demography in FS; and (4) these interactions shape the whole community, increasing the diversity compared to less heterogeneous patches constituted by single FS. We examined 459 patches and the results generally supported this hypothesis. The number of FS in a patch positively affected species diversity. Most sessile species (72% of individuals) resided on barnacles, ascidians and red algae, except barnacles that dominated the primary substrate. The size structure of barnacles (live individuals and empty shells) and ascidians were interrelated, suggesting long-term patch dynamics whereby ascidians regularly replace barnacles. Following this replacement, we expect consequent changes to the entire dependent assemblage. Evidence for these changes exists in the spatial pattern: most sessile and motile taxa demonstrated significant associations with either FS. Our results indicate that the small-scale patterns observed in patches formed by multiple FS are primarily generated by facilitation of dependent taxa by FS, and facilitation and competition between different FS. PMID:18193291

Yakovis, Eugeniy L; Artemieva, Anna V; Shunatova, Natalia N; Varfolomeeva, Marina A

2008-04-01

226

Tundra swan habitat preferences during migration in North Dakota  

USGS Publications Warehouse

I studied tundra swan (Cygnus columbianus columbianus) habitat preference in North Dakota during autumn migration, 1988-89. Many thousand tundra swans stop in the Prairie Pothole region during autumn migration, but swan resource use has not been quantified. I examined habitat preference in relation to an index of sago pondweed (Potamogeton pectinatus) presence, extent of open water, and wetland size. I compared habitat preference derived from counts of all swans to those derived from foraging swans only and cygnets only. Foraging swans preferred wetlands with sago pondweed (P = 0.03); the number of foraging swans per wetland was >4 times higher on wetlands with sago pondweed than on wetlands without sago. In contrast, nonforaging swans did not prefer wetlands with sago pondweed (P = 0.85) but preferred large wetlands (P = 0.02) and those with a high proportion of contiguous open water (P < 0.01). Thus, conclusions about habitat preference derived from counts of all swans, most of which were nonforaging, would not have revealed the importance of sago pondweed. Cygnets were more likely to be feeding than adults (P = 0.03) and occurred proportionately more often in smaller flocks (P = 0.04), but cygnets and adults had similar habitat preferences.

Earnst, Susan L.

1994-01-01

227

Assessing Functional Equivalency of Nekton Habitat in Enhanced Habitats: Comparison of Terraced and Unterraced Marsh Ponds  

E-print Network

the quality of nekton habitat created, using and comparing several metrics including nekton densityAssessing Functional Equivalency of Nekton Habitat in Enhanced Habitats: Comparison of Terraced Louisiana Fish and Wildlife Cooperative Research Unit, School of Renewable Natural Resources, Louisiana

La Peyre, Megan

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

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

230

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

231

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

PubMed

Reconstructions of paleohabitats are necessary aids in understanding hominin evolution. The morphology of species from relevant sites, understood in terms of functional relationships to habitat (termed ecomorphology), offers a direct link to habitat. Bovids are a speciose radiation that includes many habitat specialists and are abundant in the fossil record. Thus, bovids are extremely common in ecomorphological analyses. However, bovid phylogeny and habitat preference are related, which raises the possibility that analyses linking habitat with morphology are not 'taxon free' but 'taxon-dependent.' Here we analyze eight relative dimensions and one shape index of the metatarsal for a sample of 72 bovid species and one antilocaprid. The selected variables have been previously shown to have strong associations with habitat and to have functional explanations for these associations. Phylogenetic generalized least squares analyses of these variables, including habitat and size, resulted in estimates for the parameter lambda (used to model phylogenetic signal) varying from zero to one. Thus, while phylogeny, morphology, and habitat all march together among the bovids, the odds that phylogeny confounds ecomorphological analyses may vary depending on particular morphological characteristics. While large values of lambda do not necessarily indicate that habitat differences are unimportant drivers of morphology, we consider the low value of lambda for relative metatarsal width suggestive that conclusions about habitat built on observations of this particular morphology carry with them less 'phylogenetic risk.' We suggest that the way forward for ecomorphology is grounded in functionally relevant observations and careful consideration of phylogeny designed to bracket probable habitat preferences appropriately. Separate consideration of different morphological variables may help to determine the level of 'phylogenetic risk' attached to conclusions linking habitat and morphology. PMID:25038957

Scott, Robert S; Barr, W Andrew

2014-08-01

232

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

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

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

235

Cometary habitats for primitive life.  

PubMed

Comet Halley studies indicate most of the nucleus is covered by an insulating crust, presumed of pyrolysed organic material. The subcrust is warmed and percolated by gases within 2AU, so provides one habitat for primitive replicating organisms. Cracks and crevices within contaminated ice in the craters provides a habitat for photosynthesising organisms. Subsurface lakes on the Europa model, though insulated by some metres of ice, would require a trigger (perhaps meteorite impact and energy source (chemical or metabolic energy) to initiate and maintain a suitable-habitat on short period comets. Constraints on transfer between comets and other planetary bodies implies that radiation-resistant species with lengthy hibernation potential would be expected. PMID:11538150

Wallis, M K; Wickramasinghe, N C; Hoyle, F

1992-01-01

236

Habitat selection by breeding red-winged blackbirds  

USGS Publications Warehouse

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

Albers, P.H.

1978-01-01

237

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

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

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

240

Habitat Suitability Index Models: Red King Crab  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for evaluating habitat of different life stages of red king crab (Paralithodes camtschatica). A model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) and 1.0 (optimum habitat) in Alaskan coastal waters, especially in the Gulf of Alaska and the southeastern Bering Sea. HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

Jewett, Stephen C.; Onuf, Christopher P.

1988-01-01

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

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

243

Habitat complexity facilitates coexistence in a tropical ant community.  

PubMed

The role of habitat complexity in the coexistence of ant species is poorly understood. Here, we examine the influence of habitat complexity on coexistence patterns in ant communities of the remote Pacific atoll of Tokelau. The invasive yellow crazy ant, Anoplolepis gracilipes (Smith), exists in high densities on Tokelau, but still coexists with up to seven other epigeic ant species. The size-grain hypothesis (SGH) proposes that as the size of terrestrial walking organisms decreases, the perceived complexity of the environment increases and predicts that: (1) leg length increases allometrically with body size in ants, and (2) coexistence between ant species is facilitated by differential habitat use according to body size. Analysis of morphological variables revealed variation inconsistent with the morphological prediction of the SGH, as leg length increased allometrically with head length only. We also experimentally tested the ability of epigeic ants in the field to discover and dominate food resources in treatments of differing rugosity. A. gracilipes was consistently the first to discover food baits in low rugosity treatments, while smaller ant species were consistently the first to discover food baits in high rugosity treatments. In addition, A. gracilipes dominated food baits in planar treatments, while smaller ant species dominated baits in rugose treatments. We found that the normally predictable outcomes of exploitative competition between A. gracilipes and other ant species were reversed in the high rugosity treatments. Our results support the hypothesis that differential habitat use according to body size provides a mechanism for coexistence with the yellow crazy ant in Tokelau. The SGH may provide a mechanism for coexistence in other ant communities but also in communities of other terrestrial, walking insects that inhabit a complex landscape. PMID:16763839

Sarty, M; Abbott, K L; Lester, P J

2006-09-01

244

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. J. Morphol. 275:1201-1216, 2014. © 2014 Wiley Periodicals, Inc. PMID:25042704

Barr, W Andrew

2014-11-01

245

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

246

Urban residential wildlife habitat project  

Microsoft Academic Search

The Urban Residential Wildlife Habitat Program is an initiative of the Southeast Region U.S. Fish and Wildlife Service and the SouthFace Energy and Environmental Resource Center. This project is one of several that the Service's Southeast Region is involved with under a fledgling community assistance effort titled \\

Tom Baugh; Gretchen Gigley; Elizabeth Whyte; Stacey Evans

2004-01-01

247

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

Microsoft Academic Search

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

Roland A. Knapp; Haiganoush K. Preisler

1999-01-01

248

Habitat-Mediated Predator-Prey Interactions in the Eastern Gulf of Primary Investigator: Doran Mason -NOAA /GLERL  

E-print Network

Habitat-Mediated Predator-Prey Interactions in the Eastern Gulf of Mexico Primary Investigator Sponsors: Florida Sea Grant, National Marine Fisheries Service, Marine Fisheries Initiative- MARFIN-mediated predator-prey interactions and predator growth rate where H is non-consumable habitat (patch reef size

249

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

250

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

251

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

252

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...

253

Critical habitat designation: Is it prudent?  

NASA Astrophysics Data System (ADS)

The critical habitat provision of the US Endangered Species Act was believed by many to be a key feature of the Act. It was believed that this provision would benefit federally listed endangered and threatened species. However, only 23% of the listed species in the United States have their critical habitats designated. The current trend is to forego critical habitat designation because the federal government believes that the Endangered Species Act can protect most listed species without resort to the critical habitat provision. Required publication of critical habitat locations in the Federal Register may draw vandals and collectors to rare species. In other cases, existing habitat protection already provides adequate protection for species. In a few instances critical habitat changes over time and is difficult to delineate. Lastly, designating critical habitat is time consuming, delays species listing, and is controversial, detracting from the positive image of the Endangered Species Act.

Sidle, John G.

1987-08-01

254

Habitat Suitability Index Models: Rainbow Trout  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for rainbow trout (Salmo gairdneri), a freshwater species. The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for freshwater areas of the continental United States. Other habitat suitability models found in the literature are also included. Habitat suitability indexes (HSI's) are designed for use with the habitat evaluation procedures developed by the U.S. Fish and Wildlife Service. Also included are discussions of Suitability Index (SI) curves as used in the Instream Flow Incremental Methodology (IFIM) and SI curves available for an IFIM analysis of Fallfish habitat.

Raleigh, Robert F.; Hickman, Terry; Solomon, R. Charles; Nelson, Patrick C.

1984-01-01

255

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...

256

50 CFR 622.302 - Minimum mesh size.  

Code of Federal Regulations, 2013 CFR

...MEXICO, AND SOUTH ATLANTIC Pelagic Sargassum Habitat of the South Atlantic Region...size for a net used to fish for pelagic sargassum in the South Atlantic EEZ is 4...requirements may not possess any pelagic sargassum. (b)...

2013-10-01

257

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

258

Correlated percolation models of structured habitat in ecology  

NASA Astrophysics Data System (ADS)

Percolation offers acknowledged models of random media when the relevant medium characteristics can be described as a binary feature. However, when considering habitat modeling in ecology, a natural constraint comes from nearest-neighbor correlations between the suitable/unsuitable states of the spatial units forming the habitat. Such constraints are also relevant in the physics of aggregation where underlying processes may lead to a form of correlated percolation. However, in ecology, the processes leading to habitat correlations are in general not known or very complex. As proposed by Hiebeler (2000), these correlations can be captured in a lattice model by an observable aggregation parameter q, supplementing the density p of suitable sites. We investigate this model as an instance of correlated percolation. We analyze the phase diagram of the percolation transition and compute the cluster size distribution, the pair-connectedness function C(r) and the correlation function g(r). We find that while g(r) displays a power-law decrease associated with long-range correlations in a wide domain of parameter values, critical properties are compatible with the universality class of uncorrelated percolation. We contrast the correlation structures obtained respectively for the correlated percolation model and for the Ising model, and show that the diversity of habitat configurations generated by the Hiebeler model is richer than the archetypal Ising model. We also find that emergent structural properties are peculiar to the implemented algorithm, leading to questioning the notion of a well-defined model of aggregated habitat. We conclude that the choice of model and algorithm has strong consequences on what insights ecological studies can get using such models of species habitat.

Huth, Géraldine; Lesne, Annick; Munoz, François; Pitard, Estelle

2014-12-01

259

Fish habitat rehabilitation using wood in the world  

Microsoft Academic Search

To provide river managers and researchers with practical knowledge about fish rehabilitation, various studies of fish habitat\\u000a rehabilitation that used wood were reviewed. The review focuses on fish responses, wood installation methods, and geomorphic\\u000a features of the rehabilitation sites. Most studies were conducted in moderately sized (small and medium) streams with relatively\\u000a high bed gradients and aimed to improve the

Shigeya NagayamaFutoshi Nakamura; Futoshi Nakamura

2010-01-01

260

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

261

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

Microsoft Academic Search

Models of habitat associations for species often are developed with an im- plicit assumption that habitats are static, even though recent disturbance may have altered the landscape. We tested our hypothesis that trajectory and magnitude of habitat change influenced observed distribution and abundance of passerine birds breeding in shrubsteppe habitats of southwestern Idaho. Birds in this region live in dynamic

STEVEN T. K NICK; JOHN T. R OTENBERRY

2000-01-01

262

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

Microsoft Academic Search

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

Jan A. Randall

1978-01-01

263

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

264

Habitat choice in the Drosophila affinis subgroup  

Microsoft Academic Search

We investigated habitat choice in three species of Drosophila in seven mark-release-recapture experiments. We captured and recaptured flies in two floristically distinct habitats, and released them on the ecotone between the two. We recovered a total of 3800 marked flies. D. affinis males consistently showed a slight, significant tendency to return to the habitat of capture. D. athabasca, algonquin, and

Jody Hey; David Houle

1987-01-01

265

Northern Bobwhite Habitat Requirements and Evaluation Guide  

E-print Network

, bobwhite habitat has been impacted by farming, conversion of native plant communities to introduced forages, fire sup- pression, forestry practices, and urban sprawl. In rangelands, heavy grazing and herbicide negatively impacts bob- white habitat, (3, 15, 17, 26). Finally, farming has eliminated bobwhite habitat

Balasundaram, Balabhaskar "Baski"

266

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

267

TAKING HABITAT MANAGEMENT ONE STEP FURTHER  

Microsoft Academic Search

An integrated approach to bird strike prevention generally consists of habitat management, supplemented with active bird control. Habitat management is generally defined as the reduction of the numbers of problem species by removing the attracting conditions without creating new attraction for other species. Typically, habitat management is aimed at reducing (access to) food, water, rest and shelter in the runway

Arie Dekker

268

BRASH MANAGEMENT ON HABITAT RESTORATION SITES  

E-print Network

BRASH MANAGEMENT ON HABITAT RESTORATION SITES Supported financially by English Nature and the Woodland Trust Project: Brash Management on Habitat Restoration Sites Date: March 2003 Project leaders on Sustainable Woodlands & `FACT 7'Project on Environmental Land Management #12;2 BRASH MANAGEMENT ON HABITAT

269

GENERAL WILDLIFE HABITATS\\/VEGETATION COMMUNITIES  

Microsoft Academic Search

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

CHAMISE-REDSHANK CHAPARRAL

270

Mountain restoration: Soil and surface wildlife habitat  

Microsoft Academic Search

Much wildlife habitat is being destroyed by extractive resource industries in mountain environments. This article illustrates how mountain wildlife habitat was restored in a devastated area. A strip mine for coal on the east slopes of the Alberta Rockies, occupied during its operations by Rocky Mountain bighorn sheep (Ovis canadensis canadensis, Shaw 1803), was reclaimed as bighorn habitat. By considering

B. N. MacCullum; V. Geist

1992-01-01

271

CHARACTERIZATION OF ANOPHELES PSEUDOPUNCTIPENNIS LARVAL HABITATS  

Microsoft Academic Search

A survey of Anopheles pseudopunctipennis larval habitats was performed throughout most of its known geographic range. Eleven key environment variables characterized most larval habitats of this impor- tant vector of malaria in the Americas. Larval habitats occurred mainly in valley and foothill areas which were often situated in arid regions. Immatures were found primarily during the dry season in sun-exposed

SYLVIE MANGUIN; DONALD R. ROBERTS; E. L. PEYTON; ELISKA REJMANKOVA; JAMES PECOR

272

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

273

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

274

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

275

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

276

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

277

No Divergence of Habitat Selection between Male and Female Arboreal Snakes, Trimeresurus s. stejnegeri  

Microsoft Academic Search

Ming-Chung Tu, Shiuang Wang and Yu-Chun Lin (2000) No divergence of habitat selection between male and female arboreal snakes, Trimeresurus s. stejnegeri. Zoological Studies 39(2): 91-98. Sexual dimorphism in body size is a common phenomenon among animals, and possibly allows the sexes to exploit different habitats. In snakes, low body mass is valuable for arboreal life because it enables the

Ming-Chung Tu; Shiuang Wang; Yu-Chun Lin

278

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

279

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 [...

280

Habitat assessment of non-wadeable rivers in Michigan.  

PubMed

Habitat evaluation of wadeable streams based on accepted protocols provides a rapid and widely used adjunct to biological assessment. However, little effort has been devoted to habitat evaluation in non-wadeable rivers, where it is likely that protocols will differ and field logistics will be more challenging. We developed and tested a non-wadeable habitat index (NWHI) for rivers of Michigan, where non-wadeable rivers were defined as those of order >or=5, drainage area >or=1600 km2, mainstem lengths >or=100 km, and mean annual discharge >or=15 m3/s. This identified 22 candidate rivers that ranged in length from 103 to 825 km and in drainage area from 1620 to 16,860 km2. We measured 171 individual habitat variables over 2-km reaches at 35 locations on 14 rivers during 2000-2002, where mean wetted width was found to range from 32 to 185 m and mean thalweg depth from 0.8 to 8.3 m. We used correlation and principal components analysis to reduce the number of variables, and examined the spatial pattern of retained variables to exclude any that appeared to reflect spatial location rather than reach condition, resulting in 12 variables to be considered in the habitat index. The proposed NWHI included seven variables: riparian width, large woody debris, aquatic vegetation, bottom deposition, bank stability, thalweg substrate, and off-channel habitat. These variables were included because of their statistical association with independently derived measures of human disturbance in the riparian zone and the catchment, and because they are considered important in other habitat protocols or to the ecology of large rivers. Five variables were excluded because they were primarily related to river size rather than anthropogenic disturbance. This index correlated strongly with indices of disturbance based on the riparian (adjusted R2 = 0.62) and the catchment (adjusted R2 = 0.50), and distinguished the 35 river reaches into the categories of poor (2), fair (19), good (13), and excellent (1). Habitat variables retained in the NWHI differ from several used in wadeable streams, and place greater emphasis on known characteristic features of larger rivers. PMID:16132445

Wilhelm, Jennifer G O; Allan, J David; Wessell, Kelly J; Merritt, Richard W; Cummins, Kenneth W

2005-10-01

281

Integration Process for the Habitat Demonstration Unit  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

282

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

283

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

284

Does habitat fragmentation influence nest predation in the shortgrass prairie?  

USGS Publications Warehouse

We examined the effects of habitat fragmentation and vegetation structure of shortgrass prairie and Conservation Reserve Program (CRP) lands on predation rates of artificial and natural nests in northeastern Colorado. The CRP provides federal payments to landowners to take highly erodible cropland out of agricultural production. In our study area, CRP lands have been reseeded primarily with non-native grasses, and this vegetation is taller than native shortgrass prairie. We measured three indices of habitat fragmentation (patch size, degree of matrix fragmentation, and distance from edge), none of which influenced mortality rates of artificial or natural nests. Vegetation structure did influence predation rates of artificial nests; daily mortality decreased significantly with increasing vegetation height. Vegetation structure did not influence predation rates of natural nests. CRP lands and shortgrass sites did not differ with respect to mortality rates of artificial nests. Our study area is only moderately fragmented; 62% of the study area is occupied by native grassland. We conclude that the extent of habitat fragmentation in our study area does not result in increased predation in remaining patches of shortgrass prairie habitat.

Howard, M.N.; Skagen, S.K.; Kennedy, P.L.

2001-01-01

285

Ecology and habitats of extremophiles.  

PubMed

This review describes the main natural extreme environments, characterized by high temperature, high and low pH and high salinity, that can be colonized by microorganisms. The environments covered are: freshwater alkaline hot springs; acidic solfatara fields; anaerobic geothermal mud and soils; acidic sulphur and pyrite areas; carbonate springs and alkaline soil; and soda and highly saline lakes. The community structure, in terms of available energy sources and representative autotrophic and heterotrophic microorganisms, is discussed for each type of habitat. PMID:24414409

Kristjánsson, J K; Hreggvidsson, G O

1995-01-01

286

Grande Ronde Habitat Site Visits  

E-print Network

Winston Lyle Willow/OAF End Creek Huber Diversion Connection Lyle Jesse 3 Boyd 9:00 9:30 Lyle Jesse Boyd Ladd Marsh 9:35 9:45 Restroom Break Lyle Jesse 5 U Davis Dam 9:50 10:15 Lyle U Davis Dam Fish Passage Diversion Fish Passage Allen Winston, Craig 9 CC 44 12:25 1:10 Allen,Winston, Craig CC44 Erosion, habitat

287

Mapping Deep-sea Habitats  

NSDL National Science Digital Library

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

Goodwin, Mel

288

Effects of habitat fragmentation on the fitness of two common wetland species, Carex davalliana and Succisa pratensis.  

PubMed

Small habitat size and spatial isolation may cause plant populations to suffer from genetic drift and inbreeding, leading to a reduced fitness of individual plants. We examined the germination, establishment, growth, and reproductive capacity of two characteristic species of mown fen meadows, Carex davalliana, and Succisa pratensis, common in Switzerland. Plants were grown from seeds, which were collected in 18 habitat islands, differing in size and in degree of isolation. We used both common garden and reciprocal transplant experiments to assess effects of habitat fragmentation. In the common garden, plants of Carex originating from small habitat islands yielded 35% less biomass, 30% fewer tillers, and 45% fewer flowering tillers than plants from larger ones. In contrast, plants of Succisa originating from small habitat islands yielded 19% more biomass, 14% more flower heads and 35% more flowers per flower head than plants from larger ones. Moreover, plants of Succisa from small isolated habitats yielded 32% more rosettes than did plants from small connected islands. Reciprocally transplanted plants of Succisa originating from small habitat islands produced 7% more rosettes than plants from larger ones. There was no effect of small habitat size and isolation on germination and establishment of both species in the field. Our results document genetic differences in performance attributable to habitat fragmentation in both species. We suggest that fitness loss in Carex is caused by inbreeding depression, whereas in Succisa the differences in fitness are more likely caused by genetic differentiation. Our study implies that habitat fragmentation affects common habitat-specific species, such as Carex and Succisa, as well as rare ones. PMID:12647142

Hooftman, Danny A P; van Kleunen, Mark; Diemer, Matthias

2003-02-01

289

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.

Moreno, Nancy P.; Clayton, Sonia R.; Cutler, Paula H.; Young, Martha S.; Tharp, Barbara Z.

2009-01-01

290

Spatial patterns of aquatic habitat richness in the Upper Mississippi River floodplain, USA  

USGS Publications Warehouse

Interactions among hydrology and geomorphology create shifting mosaics of aquatic habitat patches in large river floodplains (e.g., main and side channels, floodplain lakes, and shallow backwater areas) and the connectivity among these habitat patches underpins high levels of biotic diversity and productivity. However, the diversity and connectivity among the habitats of most floodplain rivers have been negatively impacted by hydrologic and structural modifications that support commercial navigation and control flooding. We therefore tested the hypothesis that the rate of increase in patch richness (# of types) with increasing scale reflects anthropogenic modifications to habitat diversity and connectivity in a large floodplain river, the Upper Mississippi River (UMR). To do this, we calculated the number of aquatic habitat patch types within neighborhoods surrounding each of the ?19 million 5-m aquatic pixels of the UMR for multiple neighborhood sizes (1–100 ha). For all of the 87 river-reach focal areas we examined, changes in habitat richness (R) with increasing neighborhood length (L, # pixels) were characterized by a fractal-like power function R = Lz (R2 > 0.92 (P z) measures the rate of increase in habitat richness with neighborhood size and is related to a fractal dimension. Variation in z reflected fundamental changes to spatial patterns of aquatic habitat richness in this river system. With only a few exceptions, z exceeded the river-wide average of 0.18 in focal areas where side channels, contiguous floodplain lakes, and contiguous shallow-water areas exceeded 5%, 5%, and 10% of the floodplain respectively. In contrast, z was always less than 0.18 for focal areas where impounded water exceeded 40% of floodplain area. Our results suggest that rehabilitation efforts that target areas with <5% of the floodplain in side channels, <5% in floodplain lakes, and/or <10% in shallow-water areas could improve habitat diversity across multiple scales in the UMR.

De Jager, Nathan R.; Rohweder, Jason J.

2012-01-01

291

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

292

Effects of frugivore preferences and habitat heterogeneity on seed rain: a multi-scale analysis.  

PubMed

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*10(3) m(2); telemetry data), 'within home-range' (c. 100 m(2); telemetry data) and 'microhabitat' (<100 m(2); 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

293

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

294

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

295

Activities and preliminary results of nearshore benthic habitat mapping in southern California, 1998  

USGS Publications Warehouse

The nearshore benthic habitat of the Santa Barbara coast and Channel Islands supports a diversity of marine life that are commercially, recreationally, and intrinsically valuable. Some of these resources are known to be endangered including a variety of rockfish and the White Abalone. State and National agencies have been mandated to preserve and enhance these resources and require detailed habitat characterization in order to do so. This project will characterize and map the benthic habitat in areas that have been selected because they have been set aside as National Sanctuaries or State Preserves, or are areas of ongoing or planned fish population studies. Various management strategies are being developed to protect marine resources in the Santa Barbara Channel Islands Region. One approach under investigation is to implement no-take marine reserves (Agardy, T., 1997; Bohnsack, 1998; Roberts, 1997). One small reserve presently exists on Anacapa Island and there is a growing momentum to add additional reserves to form a reserve network (Lafferty et al., 2000). Reserves may provide relatively pristine marine communities in a wild state for study and appreciation. In addition, they may buffer some species from over-fishing. A key feature of marine reserve design is to protect a representation of the existing habitats in a region (Roberts, 1997). Unfortunately, the distribution of habitats is not well known in this area since the underwater equivalent of soils and vegetation maps that are widely available for terrestrial systems do not yet exist. Managers need habitat maps to help determine the most appropriate boundaries for reserves in a network in order to meet various criteria and goals (such as habitat representation, reserve size, habitat heterogeneity, reserve spacing, inclusion of sensitive habitats, etc.). Another use for habitat mapping is to better understand the distribution of those habitats that are particularly important to fished species or sensitive species. Combining habitat mapping with ongoing studies of egg and larval fish counts by the National Marine Fisheries Service (Russell Vetter), rockfish population studies by the California Department of Fish and Game (Dave VenTresca), and white abalone (Kevin Lafferty and others, USGS) will extend the ability to predict the distribution of these species and identify areas with appropriate habitat that might be suitable for restoration. Additional uses for habitat mapping include managing visitor use, kelp distribution, and archeological resources.

Cochrane, Guy R.; Lafferty, Kevin D.

2000-01-01

296

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

297

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

298

Habitat and Fish Responses to Multiple Agricultural Best Management Practices in a Warm Water Stream  

NASA Astrophysics Data System (ADS)

Thirteen years of annual habitat and fish sampling were used to evaluate the response of a small warm water stream in eastern Wisconsin to agricultural best management practices (BMPs). Stream physical habitat and fish communities were sampled in multiple reference and treatment stations before, during, and after upland and riparian BMP implementation in the Otter Creek subwatershed of the Sheboygan River watershed. Habitat and fish community measures varied substantially among years, and varied more at stations that had low habitat diversity, reinforcing the notion that the detection of stream responses to BMP implementation requires long term sampling. Best management practices increased substrate size; reduced sediment depth, embeddedness, and bank erosion; and improved overall habitat quality at stations where a natural vegetative buffer existed or streambank fencing was installed as a riparian BMP. There were lesser improvements at locations where only upland BMPs were implemented. Despite the habitat changes, we could not detect significant improvements in fish communities. It is speculated that the species needed to improve the fish community, mainly pollution intolerant species, suckers (Castomidae), and darters (Percidae), had been largely eliminated from the Sheboygan River watershed by broadscale agricultural nonpoint source pollution and could not colonize Otter Creek, even though habitat conditions may have been suitable.

Wang, Lizhu; Lyons, John; Kanehl, Paul

2006-08-01

299

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

300

Habitat fragmentation effects on birds in grasslands and wetlands: A critique of our knowledge  

USGS Publications Warehouse

Habitat fragmentation exacerbates the problem of habitat loss for grassland and wetland birds. Remaining patches of grasslands and wetlands may be too small, too isolated, and too influenced by edge effects to maintain viable populations of some breeding birds. Knowledge of the effects of fragmentation on bird populations is critically important for decisions about reserve design, grassland and wetland management, and implementation of cropland set-aside programs that benefit wildlife. In my review of research that has been conducted on habitat fragmentation, I found at least five common problems in the methodology used. The results of many studies are compromised by these problems: passive sampling (sampling larger areas in larger patches), confounding effects of habitat heterogeneity, consequences of inappropriate pooling of data from different species, artifacts associated with artificial nest data, and definition of actual habitat patches. As expected, some large-bodied birds with large territorial requirements, such as the northern harrier (Circus cyaneus), appear area sensitive. In addition, some small species of grassland birds favor patches of habitat far in excess of their territory size, including the Savannah (Passerculus sandwichensis), grasshopper (Ammodramus savannarum) and Henslow's (A. henslowii) sparrows, and the bobolink (Dolichonyx oryzivorus). Other species may be area sensitive as well, but the data are ambiguous. Area sensitivity among wetland birds remains unknown since virtually no studies have been based on solid methodologies. We need further research on grassland bird response to habitat that distinguishes supportable conclusions from those that may be artifactual.

Johnson, D.H.

2001-01-01

301

Squirrel monkeys ( Saimiri ) in natural habitats in Panama, Colombia, Brazil, and Peru  

Microsoft Academic Search

Troops ofSaimiri (squirrel monkeys) were observed in 31 locations in natural habitats in Panama, Colombia, Brazil, and Peru. Troop size varied from 10 to 35 animals in Panama and Colombia and from 120 to 300 or more in the unaltered rainforests of Amazonia. Troop size correlated with forest size in all areas.Saimiri associated withCebus (capuchin monkeys) in several areas.Saimiri troops

John D. Baldwin; Janice I. Baldwin

1971-01-01

302

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

303

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

304

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

305

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

306

Habitat Loss other than Fragmentation per se Decreased Nuclear and Chloroplast Genetic Diversity in a Monoecious Tree  

PubMed Central

Generally, effect of fragmentation per se on biodiversity has not been separated from the effect of habitat loss. In this paper, using nDNA and cpDNA SSRs, we studied genetic diversity of Castanopsis sclerophylla (Lindl. & Paxton) Schotty populations and decoupled the effects of habitat loss and fragmentation per se. We selected seven nuclear and six cpDNA microsatellite loci and genotyped 460 individuals from mainland and island populations, which were located in the impoundment created in 1959. Number of alleles per locus of populations in larger habitats was significantly higher than that in smaller habitats. There was a significant relationship between the number of alleles per locus and habitat size. Based on this relationship, the predicted genetic diversity of an imaginary population of size equaling the total area of the islands was lower than that of the global population on the islands. Re-sampling demonstrated that low genetic diversity of populations in small habitats was caused by unevenness in sample size. Fisher's ? index was similar among habitat types. These results indicate that the decreased nuclear and chloroplast genetic diversity of populations in smaller habitats was mainly caused by habitat loss. For nuclear and chloroplast microsatellite loci, values of FST were 0.066 and 0.893, respectively, and the calculated pollen/seed dispersal ratio was 162.2. When separated into pre-and post-fragmentation cohorts, pollen/seed ratios were 121.2 and 189.5, respectively. Our results suggest that habitat loss explains the early decrease in genetic diversity, while fragmentation per se may play a major role in inbreeding and differentiation among fragmented populations and later loss of genetic diversity. PMID:22723951

Shen, Dong-Wei; Chen, Xiao-Yong

2012-01-01

307

Habitat loss other than fragmentation per se decreased nuclear and chloroplast genetic diversity in a monoecious tree.  

PubMed

Generally, effect of fragmentation per se on biodiversity has not been separated from the effect of habitat loss. In this paper, using nDNA and cpDNA SSRs, we studied genetic diversity of Castanopsis sclerophylla (Lindl. & Paxton) Schotty populations and decoupled the effects of habitat loss and fragmentation per se. We selected seven nuclear and six cpDNA microsatellite loci and genotyped 460 individuals from mainland and island populations, which were located in the impoundment created in 1959. Number of alleles per locus of populations in larger habitats was significantly higher than that in smaller habitats. There was a significant relationship between the number of alleles per locus and habitat size. Based on this relationship, the predicted genetic diversity of an imaginary population of size equaling the total area of the islands was lower than that of the global population on the islands. Re-sampling demonstrated that low genetic diversity of populations in small habitats was caused by unevenness in sample size. Fisher's ? index was similar among habitat types. These results indicate that the decreased nuclear and chloroplast genetic diversity of populations in smaller habitats was mainly caused by habitat loss. For nuclear and chloroplast microsatellite loci, values of F(ST) were 0.066 and 0.893, respectively, and the calculated pollen/seed dispersal ratio was 162.2. When separated into pre-and post-fragmentation cohorts, pollen/seed ratios were 121.2 and 189.5, respectively. Our results suggest that habitat loss explains the early decrease in genetic diversity, while fragmentation per se may play a major role in inbreeding and differentiation among fragmented populations and later loss of genetic diversity. PMID:22723951

Zhang, Xin; Shi, Miao-Miao; Shen, Dong-Wei; Chen, Xiao-Yong

2012-01-01

308

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.

309

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

310

Measuring and modeling the spatial pattern of understory bamboo across landscapes: Implications for giant panda habitat  

NASA Astrophysics Data System (ADS)

We examined an approach to classifying understory bamboo, the staple food of the giant panda (Ailuropoda melanoleuca), from remote sensing imagery in the Wolong Nature Reserve, China. We also used these data to estimate the landscape-scale distribution of giant panda habitat, and model the human effects on forest cover and the spatio-temporal dynamics of bamboo and the resulting implications for giant panda habitat. The spatial distribution of understory bamboo was mapped using an artificial neural network and leaf-on remote sensing data. Training on a limited set of ground truth data and using widely available Landsat TM data as input, a non-linear artificial neural network achieved a classification accuracy of 80% despite the presence of co-occurring mid-story and understory vegetation. Using information on the spatial distribution of bamboo in Wolong, we compared the results of giant panda habitat analyses with and without bamboo information. Total amount of habitat decreased by 29--56% and overall habitat patch size decreased by 16--48% after bamboo information was incorporated into the analyses. The decreases in the quantity of panda habitat and increases in habitat fragmentation resulted in decreases of 41--60% in carrying capacity. Using a spatio-temporal model of bamboo dynamics and human activities, we found that local fuelwood collection and household creation will likely reduce secondary habitat relied upon by pandas. Human impacts would likely contribute up to an additional 16% loss of habitat. Furthermore, these impacts primarily occur in the habitat relied upon by giant pandas during past bamboo die-offs. Decreased total area of habitat and increased fragmentation from human activities will likely make giant pandas increasingly sensitive to natural disturbances such as cyclical bamboo die-offs. Our studies suggest that it is necessary to further examine approaches to monitor understory vegetation and incorporate understory information into wildlife habitat research and management. The success here to map bamboo has important implications for giant panda conservation and provides a good foundation for developing methods to map the spatial distributions of understory plant species. Knowledge of the spatial distribution of bamboo is necessary to accurately measure the quantity and landscape characteristics of giant panda habitat. (Abstract shortened by UMI.)

Linderman, Marc Alan

311

MOURNING DOVE NESTING HABITAT AND NEST SUCCESS IN CENTRAL MISSOURI  

Microsoft Academic Search

Previous Mourning Dove (Zenaida macroura) nesting studies conducted in areas containing a mixture of edge and continuous habitats have focused on edge habitats. Con- sequently, little is known about the potential contribution of continuous habitats to dove production. In this study we evaluated the relative importance of these two extensive habitat types by monitoring the habitat use and nest success

RONALD D. DROBNEY; JOHN H. SCHULZ; STEVEN L. SHERIFF; WESLEY J. FUEMMELER

312

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...

313

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...

314

Multistate modeling of habitat dynamics: factors affecting Florida scrub transition probabilities.  

PubMed

Many ecosystems are influenced by disturbances that create specific successional states and habitat structures that species need to persist. Estimating transition probabilities between habitat states and modeling the factors that influence such transitions have many applications for investigating and managing disturbance-prone ecosystems. We identify the correspondence between multistate capture-recapture models and Markov models of habitat dynamics. We exploit this correspondence by fitting and comparing competing models of different ecological covariates affecting habitat transition probabilities in Florida scrub and flatwoods, a habitat important to many unique plants and animals. We subdivided a large scrub and flatwoods ecosystem along central Florida's Atlantic coast into 10-ha grid cells, which approximated average territory size of the threatened Florida Scrub-Jay (Aphelocoma coerulescens), a management indicator species. We used 1.0-m resolution aerial imagery for 1994, 1999, and 2004 to classify grid cells into four habitat quality states that were directly related to Florida Scrub-Jay source-sink dynamics and management decision making. Results showed that static site features related to fire propagation (vegetation type, edges) and temporally varying disturbances (fires, mechanical cutting) best explained transition probabilities. Results indicated that much of the scrub and flatwoods ecosystem was resistant to moving from a degraded state to a desired state without mechanical cutting, an expensive restoration tool. We used habitat models parameterized with the estimated transition probabilities to investigate the consequences of alternative management scenarios on future habitat dynamics. We recommend this multistate modeling approach as being broadly applicable for studying ecosystem, land cover, or habitat dynamics. The approach provides maximum-likelihood estimates of transition parameters, including precision measures, and can be used to assess evidence among competing ecological models that describe system dynamics. PMID:21141196

Breininger, David R; Nichols, James D; Duncan, Brean W; Stolen, Eric D; Carter, Geoffrey M; Hunt, Danny K; Drese, John H

2010-11-01

315

Multistate modeling of habitat dynamics: Factors affecting Florida scrub transition probabilities  

USGS Publications Warehouse

Many ecosystems are influenced by disturbances that create specific successional states and habitat structures that species need to persist. Estimating transition probabilities between habitat states and modeling the factors that influence such transitions have many applications for investigating and managing disturbance-prone ecosystems. We identify the correspondence between multistate capture-recapture models and Markov models of habitat dynamics. We exploit this correspondence by fitting and comparing competing models of different ecological covariates affecting habitat transition probabilities in Florida scrub and flatwoods, a habitat important to many unique plants and animals. We subdivided a large scrub and flatwoods ecosystem along central Florida's Atlantic coast into 10-ha grid cells, which approximated average territory size of the threatened Florida Scrub-Jay (Aphelocoma coerulescens), a management indicator species. We used 1.0-m resolution aerial imagery for 1994, 1999, and 2004 to classify grid cells into four habitat quality states that were directly related to Florida Scrub-Jay source-sink dynamics and management decision making. Results showed that static site features related to fire propagation (vegetation type, edges) and temporally varying disturbances (fires, mechanical cutting) best explained transition probabilities. Results indicated that much of the scrub and flatwoods ecosystem was resistant to moving from a degraded state to a desired state without mechanical cutting, an expensive restoration tool. We used habitat models parameterized with the estimated transition probabilities to investigate the consequences of alternative management scenarios on future habitat dynamics. We recommend this multistate modeling approach as being broadly applicable for studying ecosystem, land cover, or habitat dynamics. The approach provides maximum-likelihood estimates of transition parameters, including precision measures, and can be used to assess evidence among competing ecological models that describe system dynamics. ?? 2010 by the Ecological Society of America.

Breininger, D.R.; Nichols, J.D.; Duncan, B.W.; Stolen, E.D.; Carter, G.M.; Hunt, D.K.; Drese, J.H.

2010-01-01

316

Relationships between nesting populations of wading birds and habitat features along the Atlantic Coast  

USGS Publications Warehouse

Using previously published atlas data for 122 mixed-species wading bird colonies on islands along the Atlantic coast (Maine to Florida, 1976-77), we examined relationships between population sizes of 11 species of egrets, herons, ibises, and wood storks (Mycteria americana) and nine habitat variables. On nautical charts, we measured four island characteristics (area, length, width, shape), three isolation factors (distances to nearest island, mainland, and a water barrier),, and two variables related to potential feeding habitat within 5 km of the center of the colony (wetland area and land-water interface, i.e., the linear distance between the marsh/upland and all water bodies within the same 5-km radius). One univariable and five multivariable .procedures were used to determine which habitat features were best related to population size .(all species combined). Multicollinearity problems among the variables limited interpretation for most procedures. Both univariable and the multivariable procedures indicated that land-water interface was the most important of the nine variables, but for all models, less than 10% of the total variance was explained (rz is less than 0.10). The size of the colony was not related to the amount of wetland area (within 5-km).per se. Colony data showed better 'structure' when examined on the basis of geographic and disturbance gradients. Population sizes of colonies near man-altered habitats were compared with those surrounded by relatively natural habitats in three geographic zones: north, middle, and south. Significant differences were found in colony size among the three zones (south largest) and between disturbance types. Surprisingly, in all three zones, colonies near man-altered areas were larger on average than those near more natural habitats in this region. A possible reason for this difference is suggested.

Erwin, R.M.; Spendelow, J.A.; Geissler, P.H.; Williams, B.K.

1987-01-01

317

ORIGINAL PAPER Patterns of space and habitat use by northern bobwhites  

E-print Network

consequences. We studied patterns of habitat selection by northern bobwhites (Colinus virginianus) on Babcock for bobwhites. Keywords Colinus virginianus . Game bird . Habitat selection . Habitat management . Habitat

Oli, Madan K.

318

Riparian fencing, grazing, and trout habitat preference on Summit Creek, Idaho  

USGS Publications Warehouse

In 1975, 3.2 km of Summit Creek, Idaho were fenced by the Bureau of Land Management to exclude livestock from the riparian area. Six stream sections were electrofished in 1979 to determine differences in trout abundance, size, and growth between grazed and ungrazed stream sections. Electrofishing stations were paired by habitat type. There were more trout in ungrazed sections than in grazed sections in all three habitat types sampled. With one exception, there were more catachable-sized (200 mm long or longer) rainbow trout (Salmo gairdneri) and brook trout (Salvelinus fontinalis) in the ungrazed area than in the grazed area. There was also evidence that the average size of the fish was less in grazed sections. Fish population data were not collected prior to fencing; therefore, it cannot be firmly concluded that the trout population increased within the livestock enclosure as a result of fencing the riparian area. However, the combined results of previous trout habitat improvements documented for Summit Creek, as a result of the fencing, and this study support the conclusion that trout prefer stream areas in ungrazed habitat over grazed habitat.

Keller, Charles R.; Burnham, Kenneth P.

1982-01-01

319

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

320

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

321

Assessing alternative anthropogenic habitats for conserving waterbirds: salinas as buffer areas against the impact of natural habitat loss for shorebirds  

Microsoft Academic Search

Because many natural waterbird habitats are threatened by human disturbance and sea level rise, it is vitally important to identify alternative wetlands that may supplement declining natural habitats. Coastal salinas are anthropogenic habitats used for obtaining salt by evaporation of sea water. These habitats support important numbers of waterbirds around the world, but their importance as feeding habitats is poorly

JOSE A. MASERO ´ ´

2003-01-01

322

Adaptive Management in Habitat Conservation Plans  

Microsoft Academic Search

Habitat conservation plans (HCPs) allow incidental take of threatened or endangered species in exchange for conservation measures that minimize and mitigate such taking. Habitat conservation plans en- tail a compromise between regulatory certainty and scientific uncertainty. This compromise is controversial because many HCPs are thought to inadequately address scientific uncertainty. Adaptive management is the systematic acquisition and application of reliable

George F. Wilhere

2002-01-01

323

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

324

Deer Initiative Conference: Deer, Habitats and Impacts  

E-print Network

Deer Initiative Conference: Deer, Habitats and Impacts Palace Hotel, Buxton, Derbyshire 23rd ­ 24th March 2007 The Deer Initiative have organised a conference to discuss deer habitats and impacts.thedeerinitiative.co.uk/html/conference.htm or contact Jackie Symmons, DI Wales, Po Box 39, Brecon LD3 8PP 01874 636148/07768 983087 The Mammal Society

Manning, Adrian D.

325

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

326

Habitats NatureScope[R] Kit.  

ERIC Educational Resources Information Center

This kit introduces the basic concepts of habitat through challenging and engaging interdisciplinary, hands-on activities. The material is designed for K-8 educators working in traditional and non- traditional classrooms with the goals of increasing awareness of the ways habitats work and why they are important. This kit consists of four…

Emerson, Eva

327

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

328

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

329

Density in habitat 1 Densityinhabitat2  

E-print Network

of solar ultraviolet rays by an organic haze13,15 . The jury is still out, but all these contradic- tory. This adaptive behaviour suggests that habitat selection is more significant in population dynamics than- viduals might be a better option. So animals maximizing fitness through habitat selection will disperse

Morris, Douglas W.

330

HABITAT MODELING APPROACHES FOR RESTORATION SITE SELECTION  

EPA Science Inventory

Numerous modeling approaches have been used to develop predictive models of species-environment and species-habitat relationships. These models have been used in conservation biology and habitat or species management, but their application to restoration efforts has been minimal...

331

Climate Change Action Pack Climate & Habitats  

E-print Network

, Shelter, Space, Key Words WILD Education Canadian Wildlife Federation Tel.: 1-800-563-WILD (9453) Fax, plants and animals, and animals and animals. The environment in which an animal lives is called its "habitat". An animal's habitat includes food, water, shelter and space in an arrangement appropriate

Gunawardena, Arunika

332

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.

333

Flare Size  

NSDL National Science Digital Library

This is an activity about determining the size of a solar flare. Learners will measure the diameter of a solar flare by making calculations using transparency grids overlaid on images of the Sun. This is the third activity as part of the "How Does HESSI Take a Picture" lesson.

334

Influences of fluctuating flows on spawning habitat and recruitment success  

NASA Astrophysics Data System (ADS)

Over the 50 years of daily peak power generation, no ramping restrictions, and loss of gravel due to operations of Philpott Dam, on Smith River, has created a wider, rectangular-shaped channel, with steeper banks. The pattern caused by channel degradation, tributary headcutting, bank erosion, and downstream aggradation has limited the length of productive habitat to between 3 and 10 river kilometers from the dam. Here the channel appears to contain key habitats where we found the highest redd densities, abundance, and spawner biomass for brown trout (Salmo trutta). Recruitment of brown trout to the fishable size classes is constrained by the daily hydropower peaking operations. The number of young brown trout produced each year was strongly related to the average magnitude of the peak flow and the duration of generation flows. Magnitude of peak flows also depressed abundance of native fishes. Although, brown trout actively removed fine sediment via redd construction and spawning, thereby increasing gravel permeability, the fine sediments from tributaries and bank erosion rapidly intruded into the spawning gravel in downstream reaches of the river. We recommend mitigating the effects of fluctuating releases from Philpott Dam through a combination of flow management and habitat improvement.

Orth, D. J.; Krause, C. W.; Novinger, D. C.

2005-05-01

335

Teaching through Trade Books: A Habitat Is a Home  

NSDL National Science Digital Library

We all have our own habitats, and this month students spend time thinking about what other organisms need to survive, what types of habitats they live in, and how to set up a habitat for a classroom animal.

Royce, Christine A.

2009-09-01

336

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

337

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

338

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

339

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

340

Use of social information for habitat selection in songbirds  

E-print Network

Habitat selection research has focused on the role of vegetative and geologic habitat characteristics or antagonistic behavioral interactions. Conspecifics can confer information about habitat quality and provide positive density-dependent effects...

Farrell, Shannon Leigh

2012-07-16

341

50 CFR 17.96 - Critical habitat-plants.  

Code of Federal Regulations, 2012 CFR

...ER09OC02.002Family Caryophyllaceae: Arenaria ursina (Bear Valley sandwort)(1) Critical habitat units for Arenaria ursina are found in San Bernardino...constituent elements of critical habitat for Arenaria ursina are the habitat...

2012-10-01

342

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...

343

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

344

Ontogenetic Variation in the Diurnal Food and Habitat Associations of an Endemic and an Exotic Fish in Floodplain Ponds: Consequences for Niche Partitioning  

Microsoft Academic Search

In floodplain ponds with low piscivore abundance, both endemic Midgley's gudgeons, Hypseleotris sp. 5, and exotic mosquitofish, Gambusia holbrooki, showed significant ontogenetic variation in the use of food and space. Small gudgeons were generally associated with surface and benthic habitats, then restricted their distribution to benthic habitats at a size of approximately 24?mm (standard length). The ontogenetic variation in mosquitofish

Rick J. Stoffels; Paul Humphries

2003-01-01

345

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

346

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

347

Habitat Suitability Index Models: Black-Capped Chickadee  

USGS Publications Warehouse

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

Schroeder, Richard L.

1983-01-01

348

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

349

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

350

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

351

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

352

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

353

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

354

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

355

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

356

Launch and Functional Considerations Guiding the Scaling and Design of Rigid Inflatable Habitat Modules  

Microsoft Academic Search

The Sasakawa International Center for Space Architecture (SICSA) has a long history of projects that involve design of space structures, including habitats for low-Earth orbit (LEO) and planetary applications. Most of these facilities and component systems are planned to comply with size, geometry and mass restrictions imposed by the Space Shuttle Orbiter's payload and lift\\/landing abort restrictions. These constraints limit

L. Bell

2002-01-01

357

atural aquatic habitats include ponds, lakes, rivers, streams, springs, estuaries, bays, and  

E-print Network

for Aquatic Animals Louis A. Helfrich, Department of Fisheries and Wildlife Sciences, Virginia Tech James, fish, and other forms of wildlife. A lake is larger and deeper than a pond. Lakes can range in size and wildlife habitats. Wetlands (marshes, swamps, bayous, and bogs) generally are shallow, low-lying areas

Liskiewicz, Maciej

358

Accuracy assessment of digitized and classified land cover data for wildlife habitat  

Microsoft Academic Search

Increasing availability of land cover data offers new opportunities for landscape-level environmental research. Accuracy reports for these data are frequently high, but for landscape-level studies, accuracy reports can be misleadingly optimistic. Focusing on land cover classes representing wildlife habitat, this paper compares the extent, size, and shape of land cover classes in two classified data sets and in data digitized

Mary Ann Cunningham

2006-01-01

359

Spatial Modeling of Harvest Constraints on Wood Supply Versus Wildlife Habitat Objectives  

Microsoft Academic Search

We studied the effects of spatial and temporal timber harvesting constraints on competing objectives of sustaining wildlife habitat supply and meeting timber harvest objectives in a boreal mixedwood forest. A hierarchical modeling approach was taken, where strategic and tactical level models were used to project blocking and scheduling of harvest blocks. Harvest block size and proximity, together with short- and

Robert S. Rempel; Cynthia K. Kaufmann

2003-01-01

360

HOME RANGES AND HABITAT USE OF SUBURBAN RED-SHOULDERED HAWKS  

EPA Science Inventory

Radio telemetry was used to determine home range size and habitat use for breeding season and non-breedng season red-shouldered hawks nesting in a surburban area in southwestern Ohio. Home ranges averaged 96.0 ha for males (n=4) and 48.3 for females (n-2) during the breeding sea...

361

Trophic disruption: a meta-analysis of how habitat fragmentation affects resource consumption in terrestrial arthropod systems.  

PubMed

Habitat fragmentation is a complex process that affects ecological systems in diverse ways, altering everything from population persistence to ecosystem function. Despite widespread recognition that habitat fragmentation can influence food web interactions, consensus on the factors underlying variation in the impacts of fragmentation across systems remains elusive. In this study, we conduct a systematic review and meta-analysis to quantify the effects of habitat fragmentation and spatial habitat structure on resource consumption in terrestrial arthropod food webs. Across 419 studies, we found a negative overall effect of fragmentation on resource consumption. Variation in effect size was extensive but predictable. Specifically, resource consumption was reduced on small, isolated habitat fragments, higher at patch edges, and neutral with respect to landscape-scale spatial variables. In general, resource consumption increased in fragmented settings for habitat generalist consumers but decreased for specialist consumers. Our study demonstrates widespread disruption of trophic interactions in fragmented habitats and describes variation among studies that is largely predictable based on the ecological traits of the interacting species. We highlight future prospects for understanding how changes in spatial habitat structure may influence trophic modules and food webs. PMID:24866984

Martinson, Holly M; Fagan, William F

2014-09-01

362

Does learning or instinct shape habitat selection?  

PubMed

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

363

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

364

Salmon River Habitat Enhancement, 1984 Annual Report.  

SciTech Connect

This report has four volumes: a Tribal project annual report (Part 1) and three reports (Parts 2, 3, and 4) prepared for the Tribes by their engineering subcontractor. The Tribal project annual report contains reports for four subprojects within Project 83-359. Subproject I involved habitat and fish inventories in Bear Valley Creek, Valley County, Idaho that will be used to evaluate responses to ongoing habitat enhancement. Subproject II is the coordination/planning activities of the Project Leader in relation to other BPA-funded habitat enhancement projects that have or will occur within the traditional Treaty (Fort Bridger Treaty of 1868) fishing areas of the Shoshone-Bannock Tribes, Fort Hall Reservation, Idaho. Subproject III involved habitat and fish inventories (pretreatment) and habitat problem identification on the Yankee Fork of the Salmon River (including Jordan Creek). Subproject IV during 1985 involved habitat problem identification in the East Fork of the Salmon River and habitat and fish inventories (pretreatment) in Herd Creek, a tributary to the East Fork.

Konopacky, Richard C.

1986-04-01

365

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

366

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

367

Selecting habitat management strategies on refuges  

USGS Publications Warehouse

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

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

1998-01-01

368

Distinguishing individual quality from habitat preference and quality in a territorial passerine.  

PubMed

Theory predicts that animals breeding in heterogeneous landscapes preferentially occupy habitats likely to maximize individual fitness, but identifying those habitats has proved problematic. Many studies develop metrics of habitat quality linked to site-specific reproductive output measured in successive years, but few separate the independent effects of individual "intrinsic quality" from those due solely to the attributes of the habitats themselves. In many populations, processes such as competitive territory defense, longevity, site-fidelity, and variation in breeding density and territory size over time have the potential to limit the degree to which individual and habitat quality will be positively related in nature. However, the effects of these processes on estimates of habitat or site-specific reproductive output have not been thoroughly investigated. We show that, in an insular population of Song Sparrows (Melospiza melodia), females nested preferentially in breeding sites with high mean reproductive output assessed over 35 years, and that variation in site-specific reproductive output was positively related to female intrinsic quality, measured here as the lifetime reproductive success of individual females relative to others hatched the same year (rLRS). In contrast, vegetation traits (shrub cover, edge, and soil depth) predicted female preference for breeding sites but did not predict site-specific variation in annual reproductive output. Female quality also did not predict which females occupied more- or less-preferred breeding sites over the study period. However, mean annual reproductive output of breeding sites estimated over 35 years was strongly positively related to the quality of the females that nested in them. Overall, these results indicate that site-specific estimates of habitat quality that do not consider the quality of the individuals occupying those sites may include substantial bias due to variation in occupant quality, and thus may not reliably predict the intrinsic effects of habitat quality on individual or population fitness. PMID:24669736

Germain, Ryan R; Arcese, Peter

2014-02-01

369

Strong Predictability Of Spatially Distributed Physical Habitat Preferences For O. Mykiss Spawning Across Three Spatial Scales  

NASA Astrophysics Data System (ADS)

Currently accepted perception assumes Oncorhynchus mykiss prefer different ranges of similar physical habitat elements for spawning than Chinook salmon (Oncorhynchus tshawytscha), taking into account their difference in size. While there is increasing research interest regarding O. mykiss habitat use and migratory behavior, research conducted to date distinguishing the physical habitat conditions utilized for O. mykiss spawning has not provided quantified understanding of their spawning habitat preferences. The purpose of this study was to use electivity indices and other measures to assess the physical habitat characteristics preferred for O. mykiss spawning in terms of both 1-m scale microhabitat attributes, and landforms at different spatial scales from 0.1-100 times channel width. The testbed for this study was the 37.5-km regulated gravel-cobble Lower Yuba River (LYR). Using spatially distributed 2D hydrodynamic model results, substrate mapping, and a census of O. mykiss redds from two years of observation, micro- and meso-scale representations of physical habitat were tested for their ability to predict spawning habitat preference and avoidance. Overall there was strong stratification of O. mykiss redd occurrence for all representation types of physical habitat. A strong preference of hydraulic conditions was shown for mean water column velocities of 1.18-2.25 ft/s, and water depths of 1.25-2.76 ft. There was a marked preference for the two most upstream alluvial reaches of the LYR (out of 8 total reaches), accounting for 92% of all redds observed. The preferred morphological units (MUs) for O. mykiss spawning were more variable than for Chinook salmon and changed with increasing discharge, demonstrating that O. mykiss shift spawning to different MUs in order to utilize their preferred hydraulic conditions. The substrate range preferred for O. mykiss spawning was within 32-90 mm. Overall, O. mykiss spawning behavior was highly predictable and required a holistic blend of hydraulic and geomorphic representations to explain.

Kammel, L.; Pasternack, G. B.; Wyrick, J. R.; Massa, D.; Bratovich, P.; Johnson, T.

2012-12-01

370

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

371

Food regulates reproduction differently in different habitats: experimental evidence in the Goshawk.  

PubMed

Food supplementation experiments have been widely used to get detailed insight into how food supply contributes to the reproductive performance of wild animals. Surprisingly, even though food seldom is distributed evenly in space, variation in local habitat quality has usually not been controlled for in food supplementation studies. With results from a two-year feeding experiment involving a habitat-sensitive avian top predator, the Northern Goshawk Accipiter gentilis, we show that treatment effects on goshawk reproductive performance are habitat dependent. Extra food reduced nestling mortality in low-quality territories where prime habitat (forest) is scarce, but not in high-quality territories where prime habitat is abundant. Consequently, brood size did not differ between treatment categories in heavily forested territories, but fledgling numbers differed between unfed and fed goshawk pairs breeding in territories where forest is scarce. However, because extra food was not superabundant, this artificial increase in offspring number induced a dramatic decrease in nestling condition in low-quality territories. Treatment effects were detected even after controlling statistically for other potentially confounding effects (year, territory identity) and strongly covaried with territory-specific abundances of the most important summer prey species. These results highlight the importance of acknowledging the effect that small-scale variation in habitat quality and availability of natural food may have on the results of food supplementation experiments. In order to assess the generality of food supplementation effects, the integration of habitat heterogeneity and variation in food abundance is thus needed, especially among species in which small-scale variation in habitat quality influences demographic patterns. PMID:18589533

Byholm, Patrik; Kekkonen, Mari

2008-06-01

372

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

373

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

374

The historic influence of dams on diadromous fish habitat with a focus on river herring and hydrologic longitudinal connectivity  

Microsoft Academic Search

The erection of dams alters habitat and longitudinal stream connectivity for migratory diadromous and potamodromous fish species\\u000a and interrupts much of organismal exchange between freshwater and marine ecosystems. In the US, this disruption began with\\u000a colonial settlement in the seventeenth century but little quantitative assessment of historical impact on accessible habitat\\u000a and population size has been conducted. We used published

Carolyn J. Hall; Adrian Jordaan; Michael G. Frisk

2011-01-01

375

Foraging behaviour of non-breeding Western Sandpipers Calidris mauri as a function of sex, habitat and flocking  

Microsoft Academic Search

Individuals within a population may vary considerably in the way they exploit available food resources. If the sexes differ in the size of their feeding apparatus, there can be differences in foraging behaviour and habitat use, hence one sex may be more susceptible to competi- tion. We examined relationships between sexual dimorphism in bill size and foraging behav- iour, and

GUILLERMO FERNÁNDEZ; DAVID B. LANK

2008-01-01

376

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

377

Does attraction to conspecifics explain the patch-size effect? An experimental test  

Microsoft Academic Search

Recent theory suggests that attraction to conspecifics during habitat selection can be one potential, yet untested, mechanism for animal sensitivity to habitat fragmentation. The least flycatcher Empidonax minimus, a highly territorial migratory bird, has previously been shown to be attracted to conspecifics and sensitive to patch size by avoiding small patches of riparian forest in Montana, USA. I used a

Robert J. Fletcher

2009-01-01

378

Gulf of Maine Marine Habitat Primer  

NSDL National Science Digital Library

This book provides an overview of the Gulf of Maine's coastal and offshore habitats for resource managers and other coastal decision-makers in government, Non-Government Organizations (NGOs), and the private sector. Illustrated with color photographs and drawings, the primer describes habitat characteristics, ecological functions, economic and recreational values, human impacts, and management considerations. It is intended as a tool for resource managers, planners, legislators, conservation commissioners, NGO staff members, and other people seeking a better understanding of marine habitats from Massachusetts to Nova Scotia. The book is available in six downloadable sections, or it can be ordered as a hard copy.

379

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

380

Habitat comparisons and productivity in nesting common terns on the mid-Atlantic coast  

USGS Publications Warehouse

Nesting Common Terns (Sterna hirundo) were studied at a number of barrier beaches and small islands of tidal salt marsh in New Jersey and the Eastern Shore of Maryland-Virginina from 1980 through 1982. Data were collected on clutch sizes, nest spacing, and nesting success. The principal null hypothesis tested was that no difference in reproductive success exists between beach and marsh habitats. Nests were monitored from egg-laying in mid-May until mid-July when young fledged. Clutch sizes varied among colonies and across years but no systematic effect of year, habitat, or colony size on mean clutch size per colony was detected. Analyses of nest productivity (estimated using both the Mayfield method and using a colony average) failed to reveal significant effects of habitat or colony size but showed a stronger year effect. Storm tide flooding and egg chick disappearance (presumably predation by Herring Gulls Larus argentatus and Laughing Gulls L. atricilla nesting nearby) accounted for most nest failures. Losses due to both these mortality factors were unpredictable from year to year. Nest spacing in salt marsh colonies was much closer than it was on barrier beaches. In mixed-species colonies with Black Skimmers (Rynchops niger), distances between tern and skimmer nests were also much smaller in marsh colonies than they were on beaches. The limited amount of wrack (windrows of dead, matted vegetation) preferred by marsh-nesting terns probably explains these spacing differences. Several lines of evidence suggest that terns prefer beaches to marshes for nesting, however, the uncertainty of predation and flooding may often obscure any intrinsic differences in habitat quality. Long-term field studies are essential for testing hypotheses related to differential fitness of individuals among habitats.

Erwin, R.M.; Smith, D.C.

1985-01-01

381

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

382

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

383

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

384

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

PubMed

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

2013-08-22

385

Quantifying structural physical habitat attributes using LIDAR and hyperspectral imagery.  

PubMed

Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity, and riparian vegetation cover and structure. The Environmental Monitoring and Assessment Program (EMAP) is designed to assess the status and trends of ecological resources at different scales. High-resolution remote sensing provides unique capabilities in detecting a variety of features and indicators of environmental health and condition. LIDAR is an airborne scanning laser system that provides data on topography, channel dimensions (width, depth), slope, channel complexity (residual pools, volume, morphometric complexity, hydraulic roughness), riparian vegetation (height and density), dimensions of riparian zone, anthropogenic alterations and disturbances, and channel and riparian interaction. Hyperspectral aerial imagery offers the advantage of high spectral and spatial resolution allowing for the detection and identification of riparian vegetation and natural and anthropogenic features at a resolution not possible with satellite imagery. When combined, or fused, these technologies comprise a powerful geospatial data set for assessing and monitoring lentic and lotic environmental characteristics and condition. PMID:19165614

Hall, Robert K; Watkins, Russell L; Heggem, Daniel T; Jones, K Bruce; Kaufmann, Philip R; Moore, Steven B; Gregory, Sandra J

2009-12-01

386

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

387

SALMON SPAWNING & REARING HABITAT IN OREGON  

EPA Science Inventory

Spawning & rearing, rearing only, and essential habitat identified by Oregon Dept. Fish & Wildlife for chum, coho, fall chinook, and spring chinook salmon in Oregon. Each of the species workspaces contains coverages specific to individual USGS hydrologic cataloging unit; each co...

388

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

389

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...

390

Using Livestock to Manage Wildlife Habitat  

E-print Network

Livestock grazing can be an effective tool in managing wildlife habitat. This publication explains how grazing affects various wildlife species such as white-tailed deer, bobwhite quail and turkeys, and how to select the type of livestock needed...

Lyons, Robert K.; Wright, Byron D.

2003-06-19

391

EPA'S BENTHIC HABITAT DATA FOR YAQUINA ESTUARY  

EPA Science Inventory

Scientists at EPA's National Health and Environmental Effects Research Laboratory, Western Ecology Division (WED) have been studying seafloor (benthic) habitats in Yaquina estuary for several years. Those studies were conducted as parts of several research projects, including: e...

392

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

393

Online Courses: WCS: Habitat Ecology for Educators  

NSDL National Science Digital Library

Living things have evolved over millions of years to exist in particular environments. We call those environments habitats, and we say that species are adapted to them. The interrelationships among plants, animals, climate, and seasons of a particular hab

1900-01-01

394

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...

395

Focal Species and Representative Habitats Chuck Peven  

E-print Network

Focal Species and Representative Habitats Chuck Peven Peven Consulting, Inc. Wenatchee Subbasin in a theoretically sound and consistent manner to a known though low degree of accuracy (+/- 50%) has merit

396

Coexistence of habitat specialists and generalists in metapopulation models of multiple-habitat landscapes.  

PubMed

In coarse-grained environments specialists are generally predicted to dominate. Empirically, however, coexistence with generalists is often observed. We present a simple, but previously unrecognized, mechanism for coexistence of a habitat generalist and a number of habitat specialist species. In our model all species have a metapopulation structure in a landscape consisting of patches of different habitat types, governed by local extinction and colonization. Each specialist is limited to its specific type of habitat. The generalist can use more types of habitat, has a lower local competitive ability but can exploit patches left open by the specialists. Our modeling shows that coexistence is easily possible. The mechanism amounts to a colonization/competition trade-off at the landscape level, where the colonization advantage of the inferior competitor does not arise from a higher colonization rate but from its ability to use more types of habitat. Habitat availability has to be intermediate: when there are few patches of each habitat, only the generalist is able to maintain itself and when there are many patches, high propagule pressure of the specialists excludes the generalist. Habitat selection or temporal variations in relative habitat quality are not necessary for coexistence. Increased niche-width, colonization rate or local competitive ability of the generalist enhances its performance compared to the specialists. Various types of habitat degradation favour generalism. When able to use a broad range of habitats, generalists can generate so much propagule pressure that only a low level of local competitive ability is needed to globally exclude the specialists. Hence, in a reversal of the original problem, the question is why there are so many specialist metapopulations? PMID:23943092

Nagelkerke, Cornelis J; Menken, Steph B J

2013-12-01

397

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

398

Foraging habitats of bats in southern Finland  

Microsoft Academic Search

We determined the foraging habitats of the northern batEptesicus nilssonii (Keyserling et Blasius, 1839), Brandt’s batMyotis brandtii (Eversmann, 1845), whiskered batMyotis mystacinus (Kuhl, 1819), Daubenton’s batMyotis daubentonii (Kuhl, 1819) and brown long-eared batPlecotus auritus (Linnaeus, 1758) in southern Finland. Among these species, we compared the diversities of foraging habitats, linear feature\\u000a preference and the bats’ tendencies to forage simultaneously.Eptesicus nilssonii

Terhi Wermundsen; Yrjö Siivonen

2008-01-01

399

The habitat of nesting whooping cranes  

Microsoft Academic Search

Through a spatial, multi-scale approach I compared available habitat with habitat used by whooping cranes (Grus americana) on their nesting grounds in Wood Buffalo National Park, Canada. Thirty-two study sites (16 used, 16 available) were established in the nesting area in August 1996. Data were gathered by (a) plots of 9.8 m radius which provided detailed site data and served

Kevin Timoney

1999-01-01

400

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

401

Selecting trout habitat suitability criteria for instream flow studies  

SciTech Connect

Habitat suitability criteria (HSC) are a major component of the Instream Flow Incremental Methodology (IFIM) developed by the U.S. Fish and Wildlife Service (USFWS) to estimate the relationship between streamflow and fish habitat. Studies using the IFIM are used to allocate and manage water resources at hydroelectric projects and other streamflow regulating facilities. HSC are developed by observing fish in the wild, usually by snorkeling, and then performing a frequency analysis of the microhabitat features, such as the depth and velocity that the fish were seen using. The resulting HSC are specific to the particular stream reach at the time of observation. To aid selection of HSC for sites where HSC cannot be developed because of an insufficient number of fish to observe, poor visibility, or inaccessible study sites, we investigated the literature to find factors that affect HSC for rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta). Key factors found to significantly affect trout HSC included fish size, season, stream structure, competition, and food availability. The primary determinant in microhabitat selection and the resulting HSC was trout size. Generally, as their size increases, trout occupy swifter, deeper water. The literature review showed that transferring HSC from one stream PHABSIM site to another is valid only if the trout size distribution, species composition, stream structure, season when HSC data were collected, and other variables such as water temperature and food availability are sufficiently similar between the sites. The results of this study imply that HSC developed from data collected at numerous sites, where these factors varied widely or are unknown, cannot be assumed to apply to a particular study site. It is more appropriate to select HSC from a single stream site that is most similar to the new PHABSIM site in its physical and biological factors.

Lambert, T.R. [Pacific Gas and Electric Co., San Ramon, CA (United States); Hanson, D.F. [EA Engineering, Science, and Technology, Lafayette, CA (United States)

1995-12-31

402

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

403

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

404

Factors Affecting Habitat Use by Appalachian Ruffed Grouse  

Microsoft Academic Search

A goal of many resource selection studies is to identify those habitats selected by a species. However, favorability of a particular habitat feature is likely contingent on such factors as landscape composition, predation risk, and an individual's resource needs. Thus, habitat selection may vary depending on context, and identifying causes of variability in habitat use could increase our understanding of

DARROCH M. WHITAKER; DEAN F. STAUFFER; GARY W. NORMAN; PATRICK K. DEVERS; THOMAS J. ALLEN; STEVE BITTNER; DAVID BUEHLER; JOHN EDWARDS; SCOTT FRIEDHOFF; WILLIAM M. GIULIANO; CRAIG A. HARPER; BRIAN TEFFT

2006-01-01

405

How many habitats are there in the sea (and where)?  

Microsoft Academic Search

Current policies of habitat conservation, recovery, and management are strongly biased in favour of terrestrial systems, being poorly applicable to marine environments. A sound habitat classification, leading to spatially explicit accounts on the distribution of marine habitats and communities, is a prerequisite to identify conservation priorities, based on appropriate methods for assessing habitat sensitivity to human disturbance, aimed at preventing

Simonetta Fraschetti; Antonio Terlizzi; Ferdinando Boero

2008-01-01

406

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.

407

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

408

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...

409

WILDLIFE HABITAT RELATIONS IN THE EVERGLADES AGRICULTURAL AREA  

E-print Network

WILDLIFE HABITAT RELATIONS IN THE EVERGLADES AGRICULTURAL AREA 2003 Report #12;Wildlife Habitat habitat of the Everglades Agricultural Area (EAA) is situated within a matrix of natural habitat and urban areas of South Florida. This area has not been widely studied and little is known about the wildlife

Mazzotti, Frank

410

WBIO 370 Wildlife Habitat Conservation & Management Spring 2009 3 Credits  

E-print Network

Urban wildlife habitat issues Wildlife habitat assignment due 16 19-Mar Lab 1: Grant Creek Field TripSyllabus: WBIO 370 Wildlife Habitat Conservation & Management Spring 2009 ­ 3 Credits Dr. Mark a familiarity with the theoretical underpinnings of the importance of habitat to wildlife species in terrestrial

Hebblewhite, Mark

411

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

412

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

413

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 (2007â€"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 km 2) 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 km 2) 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, Tyler L.; Flint, Paul L.; Derksen, Dirk V.; Schmutz, Joel A.

2011-01-01

414

Comparison of Mauthner cell size in teleosts.  

PubMed

The Mauthner cells (M-cells) are a pair of neurons found in the medulla oblongata of most fish and amphibians. This neuron is not the same size in all teleosts. Based on the hypothesis that differences in M-cell size might be related to fish family and possibly fish habitat, M-cell and nuclear size were compared between fish families. In order to minimize effects of fish length on cell or nuclear size, statistical treatment of the data was made for four separate length classes. The results indicate at least three groupings by cell or nuclear size. The cell is large in fish from the Salmonidae, Catostomidae and Cyprinidae, small in the Stichaeidae, Cottidae and Pleuronectidae and absent in Batrachoididae, Lophiidae, Ogcocephalidae and Cylopteridae. In general a correlation exists between fish that lack or have small M-cells and a demersal habitat. Since these fish may rely on camouflage for protection against predation, the M-cells may have altered excitability or function as compared to more active fish in which the M-cell is known to function in initiating the startle response (larval zebrafish and goldfish). Differences in input to M-cells of different sizes in conjunction with known electrophysiological properties of the goldfish M-cell are discussed in relation to the function of this neuron. PMID:632379

Zottoli, S J

1978-04-15

415

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

416

Estimating Coho Salmon Rearing Habitat and Smolt Production Losses in a Large River Basin, and Implications for Habitat Restoration  

Microsoft Academic Search

To develop a habitat restoration strategy for the 8,270-km Skagit River basin, we estimated changes in smolt production of coho salmon Oncorhynchus kisutch since European settlement began in the basin, based on changes in summer and winter rearing habitat areas. We assessed changes in coho salmon smolt production by habitat type and by cause of habitat alteration. We estimated that

T. Beechie; E. Beamer; L. Wasserman

1994-01-01

417

Prisoners in Their Habitat? Generalist Dispersal by Habitat Specialists: A Case Study in Southern Water Vole (Arvicola sapidus)  

Microsoft Academic Search

Habitat specialists inhabiting scarce and scattered habitat patches pose interesting questions related to dispersal such as how specialized terrestrial mammals do to colonize distant patches crossing hostile matrices. We assess dispersal patterns of the southern water vole (Arvicola sapidus), a habitat specialist whose habitat patches are distributed through less than 2% of the study area (overall 600 km2) and whose

Alejandro Centeno-Cuadros; Jacinto Román; Miguel Delibes; José Antonio Godoy

2011-01-01

418

Habitat Suitability Index Models: Bald Eagle (Breeding Season)  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the bald eagle (Haliaeetus leucocephalus). 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.

Peterson, Allen

1986-01-01

419

Habitat Suitability Index Models: Blue-Winged Teal (Breeding)  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the blue-winged teal (Anas discors). 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

420

Habitat Suitability Index Models: Red-Winged Blackbird  

USGS Publications Warehouse

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

Short, Henry L.

1985-01-01

421

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

422

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

423

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 wetland and shrub habitat, was a concentrated area of highly suitable habitat, while areas at higher elevation areas were less suitable. Female bobcat home ranges, on average, had an average habitat suitability score of near 0, indicating that home ranges consisted of both beneficial and detrimental habitat types. We discuss