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1

Association Between Habitat Size, Brushtail Possum Density, and the Mosquito Fauna of Native Forests in the Auckland Region, New Zealand  

Microsoft Academic Search

Human activities have been causing dramatic and unprecedented changes to the Earth’s ecosystems, and are a primary factor\\u000a associated with biological invasions. Disturbed and fragmented habitats allow some vector mosquitoes to thrive. The New Zealand\\u000a landscape has been extensively modified since the arrival of humans, and there is accumulating evidence that the distribution\\u000a of mosquitoes is being altered as a

José G. B. Derraik

2009-01-01

2

Estimating population size of endangered brush-tailed rock-wallaby (Petrogale penicillata) colonies using faecal DNA.  

PubMed

The brush-tailed rock-wallaby (Petrogale penicillata) is an endangered species in southeastern Australia and many of the remaining populations are declining. The steep rocky habitat and shy nature of the species make it difficult to obtain data on population parameters such as abundance and recruitment. Faecal pellet counts from scat plots are commonly used to monitor population trends but these are imprecise and difficult to relate to absolute population size. We conducted a noninvasive genetic sampling 'mark-recapture' study over a 2-year period to identify individuals from faecal DNA samples and estimate the population size of four brush-tailed rock-wallaby colonies located in Wollemi National Park, New South Wales. Scat plots in rock-wallaby colonies were used as sample collection points for this study. Two separate population estimates were carried out for three of the colonies to determine if we could detect recruitment and changes in population size. We determined that there was one large colony of an estimated 67 individuals (95% confidence interval: 55-91) and three smaller colonies. Monitoring of the smaller colonies also detected possible population size increases in all three. Our results indicate that faecal DNA analysis may be a promising method for estimating and monitoring population trends in this species particularly when used with a traditional field survey method. PMID:16367832

Piggott, M P; Banks, S C; Stone, N; Banffy, C; Taylor, A C

2006-01-01

3

Body size, age and paternity in common brushtail possums ( Trichosurus vulpecula )  

Microsoft Academic Search

Sexual selection should produce sexual size dimorphism in species where larger members of one sex obtain disproportionately more matings. Recent theory suggests that the degree of sexual size dimorphism depends on physical and temporal constraints involving the operational sex ratio, the potential reproductive rate and the trade-off between current reproductive effort and residual reproductive value. As part of a large-scale

M. CLINCHY; A. C. T AYLOR; L. Y. Z ANETTE; C. J. K REBS; P. J. JARMAN

2004-01-01

4

Habitat size and bird community management  

USGS Publications Warehouse

The purpose of this paper is to review the results in the literature that show the effect of area of forest on nesting migratory bird species, and to present the results of additional field work that we have conducted in forest habitats in western Maryland. These results indicate the area sensitivity of many long distance migrants. Because 80 to 95 percent of the breeding birds in the northeastern deciduous forest are neotropical migrants, the changes in bird species composition as a result of forest fragmentation can be immense. Management strategies based on habitat size are suggested to assist in maintaining communities of nesting migratory birds.

Anderson, S.H.; Robbins, C.S.

1981-01-01

5

Inflatable rigidizable human habitat of large size  

NASA Astrophysics Data System (ADS)

Human organism is sensitive to space environment factors such as temperature variations, ra-diation, microgravity, that exist in all space missions on the board of space ships and space stations on Low Earth Orbit (LEO). The materials and constructions of modern space ships and ISS provide acceptable conditions for human crew during some months on the LEO. Fu-ture space flights to Moon, Mars and further will require new materials and stronger protection against high intensity solar irradiation, which could kill living organisms when flight is over the radiation belt of Earth. One of the modern project for future space flight is a large size habitat based on inflatable technology with rigidization of the habitat walls after deployment. The requirements for radiation protection, stable inflating, rigidization and sufficient mechan-ical properties during long life-time of the habitat are key question for selection of a suitable materials of the habitat. The properties of the inflatable rigidizable habitat to save life in far space are considered and discussed.

Kondyurin, Alexey

6

Routine blood values for New Zealand brushtail possums at capture  

Microsoft Academic Search

ExtractThank you for the opportunity to reply to Dr Clark's and Ms Cooke's recent letters. As stated in our original letter “Routine blood values for New Zealand brushtail possums (Trichosurus vulpecula) at capture”, the brushtail possum is the subject of intense and diverse study throughout the country (Lynch, 1997). Part of this study focuses on finding disease agents that may

J. OKeefe; M. Wickstrom

1998-01-01

7

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.

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

2013-01-01

8

The influence of neighborhood size and habitat shape on the accumulation of deleterious mutations.  

PubMed

To examine the impact of genetic neighborhood size and habitat shape on genetic load and the accumulation of deleterious mutation, individual-based simulations were performed in continuously distributed habitats. The risk of extinction increased as both the area of the habitat and the neighborhood size decreased. When the neighborhood area became smaller than the habitat area, habitat shape also began to influence the risk of extinction by mutation loads, expected time to extinction being shorter in longer and narrower habitats than in a square habitat. Both the number of homozygous deleterious loci per individual and the mutation load in the population increased as the neighborhood size and total population size decreased. Neighborhood size and total population size both independently affected the average number of homozygous deleterious loci per individual. In addition, as the ratio of the long to the short side of the rectangle of a habitat increased, the average number of homozygous deleterious loci increased. When the areas of the habitats were held constant, the average number of homozygous loci and the mutation loads were smallest for a regular square and largest for the longest, narrowest habitat. These results suggest that the spatial genetic structure of an individual is an important factor in the accumulation of deleterious mutations and the risk of extinction by mutation meltdown. PMID:11444951

Kawata, M

2001-08-01

9

Home range size of willow tits: a response to winter habitat loss.  

PubMed

We examined the behavioral response to habitat loss and fragmentation of willow tits (Parus montanus) in winter in a mosaic forest landscape in northern Finland. We studied habitat preference, flock size and home range size of 16 flocks, half of which had their territories in forests fragmented by forestry and half in continuous forest. We predicted that birds would respond to habitat loss by enlarging their home range and/or diminishing group size. In addition, to compensate for fragmentation effects, willow tits might be expected to include more optimal habitat into their territories. Flocks included on average 3.9 birds and occupied territories of 12.6 ha. Willow tits avoided open areas (clear cuts and young sapling stands) and preferred mature forests and older sapling stands or pine bogs equally. Birds responded to habitat loss by enlarging their home ranges but not by reducing the group size. Large territories included a smaller proportion of mature forests, but the proportion of sapling and pine bog habitat did not change. Birds on territories that included a large proportion of open habitat localized their activity on several distinct habitat patches that were distributed over a wide area. We conclude that willow tits adjust territory use to compensate for the inclusion of unsuitable habitat within home ranges, and older sapling areas and pine bogs serve as surrogates for mature forests. However, birds did not enlarge the proportion of forest habitat in their territories with increasing habitat loss. Thus, our data do not suggest a strong effect of fragmentation, but imply that forestry practices reduce suitable wintering habitat and carrying capacity in the area. Thus winter habitat loss may explain the observed population decline of willow tits in Finland during recent decades. PMID:12845515

Siffczyk, Claudia; Brotons, Lluís; Kangas, Katja; Orell, Markku

2003-07-05

10

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

SciTech Connect

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

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

2001-12-01

11

Laboratory Evaluation of Odor Preferences of the Brushtail Possum  

Microsoft Academic Search

The Australian brushtail possum (Trichosurus vulpecula) is the major vertebrate pest in New Zealand. Possums cause significant damage to the country's native and exotic forests and, as a vector of bovine tuberculosis, are a serious threat to the country's meat industry. Strong smelling odors are often used as lures during possum control operations in New Zealand, but little is known

J. H. Todd; C. E. O'Connor; J. R. Waas

1998-01-01

12

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

Microsoft Academic Search

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

NANCY E. McINTYREl; John A. Wiens

1999-01-01

13

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...

14

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

Microsoft Academic Search

? Background and Aims Flowers are relatively invariant organs within species, but quantitative variation often exists among conspecifics. These variations represent the raw material that natural selection can magnify, eventually resulting in morphological divergence and diversification. This paper investigates floral variability in Rosmarinus officinalis, a Mediterranean shrub. ? Methods Nine populations were selected in three major southern Spanish habitats (coast,

JAVIER HERRERA

2005-01-01

15

Habitat  

NSDL National Science Digital Library

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

Ptv, Idaho

2011-09-21

16

THE RELATIONSHIP BETWEEN SEXUAL SIZE DIMORPHISM AND HABITAT USE IN GREATER ANTILLEAN ANOLIS LIZARDS  

Microsoft Academic Search

Sexual size dimorphism (SSD) is the evolutionary result of selection operating differently on the body sizes of males and females. Anolis lizard species of the Greater Antilles have been classified into ecomorph classes, largely on the basis of their structural habitat (perch height and diameter). We show that the major ecomorph classes differ in degree of SSD. At least two

Marguerite A. Butler; Thomas W. Schoener; Jonathan B. Losos

2000-01-01

17

Size and biomagnification: How Habitat selection explains beluga mercury levels.  

PubMed

Mercury (Hg) levels in the Beaufort Sea beluga (Delphinapterus leucas) population increased during the 1990s; levels have since declined but remain higher than the 1980s. The diet of this beluga population is not well-known, thus it is difficult to assess dietary Hg sources. During the summer, the Beaufort Sea belugas segregate by length, sex, and reproductive status corresponding to habitat use that may result in feeding differences and ultimately Hg uptake. To test this hypothesis, we examine beluga dietary variation using fatty acid profiles and determine which biological variables best predict diet Relationships between biological variables and fatty acids were further evaluated with stable isotopes and Hg concentrations in liver and muscle. Hg concentrations in muscle were better related to liver delta15N than muscle delta15N. Stable isotopes and fatty acids are compared in their ability to describe dietary Hg processes in beluga. Fatty acids provided support for influences of whale behavior on dietary Hg uptake, whereas stable isotopes inferred tissue Hg metabolic rates. Here, we show beluga length drives diet variability leading to differences in Hg uptake and biomagnification processes dominate beluga Hg levels over Hg bioaccumulation over time. PMID:18589955

Loseto, L L; Stern, G A; Ferguson, S H

2008-06-01

18

Fish size and habitat depth relationships in headwater streams  

Microsoft Academic Search

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

B. C. Harvey; A. J. Stewart

1991-01-01

19

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

EPA Science Inventory

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

20

Habitat, Density and Group Size of Primates in a Brazilian Tropical Forest  

Microsoft Academic Search

Habitats, population densities and group sizes of 5 primate species (Callithrix flaviceps, Callicebus personatus personatus, Cebus apella nigritus, Alouatta fusca clamitans, and Brachyteles arachnoides) were estimated, using the method of repeated transect sampling, in an area of montane pluvial forest in eastern Brazil (Atlantic forest). A. fusca and C. apella had the highest densities in terms of groups and individuals

Luiz Paulo S. Pinto; Claudia M. R. Costa; Karen B. Strier; Gustavo A. B. da Fonseca

1993-01-01

21

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...

22

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

PubMed

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

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

2012-02-22

23

Importance of habitat patch size for occupancy and density of aspen-associated saproxylic beetles  

Microsoft Academic Search

In Fennoscandian boreal forests, aspen (Populus tremula) is one of the most important tree species for biodiversity. In this study we explore how occupancy and density of beetles\\u000a associated with dead aspen are related to habitat patch size and connectedness in a 45,000 ha boreal managed forest landscape\\u000a in central Sweden. Patch size was estimated as amount of breeding substrate and

Erik Sahlin; Leif Martin Schroeder

2010-01-01

24

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

25

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

26

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

PubMed

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

Steiner, Sascha Claus Christoff; Willette, Demian Alexander

2010-06-01

27

Prevalence and Genetic Characterization of Cryptosporidium Isolates from Common Brushtail Possums (Trichosurus vulpecula) Adapted to Urban Settings?  

PubMed Central

The common brushtail possum (Trichosurus vulpecula) is one of the most abundant native marsupials in urban Australia, having successfully adapted to utilize anthropogenic resources. The habituation of possums to food and shelter available in human settlements has facilitated interaction with people, pets, and zoo animals, increasing the potential for transmission of zoonotic Cryptosporidium pathogens. This study sought to examine the identity and prevalence of Cryptosporidium species occurring in possums adapted to urban settings compared to possums inhabiting remote woodlands far from urban areas and to characterize the health of the host in response to oocyst shedding. Findings indicated that both populations were shedding oocysts of the same genotype (brushtail possum 1 [BTP1]) that were genetically and morphologically distinct from zoonotic species and genotypes and most closely related to Cryptosporidium species from marsupials. The urban population was shedding an additional five Cryptosporidium isolates that were genetically distinct from BTP1 and formed a sister clade with Cryptosporidium parvum and Cryptosporidium hominis. Possums that were shedding oocysts showed no evidence of pathogenic changes, including elevated levels of white blood cells, diminished body condition (body mass divided by skeletal body length), or reduced nutritional state, suggesting a stable host-parasite relationship typical of Cryptosporidium species that are adapted to the host. Overall, Cryptosporidium occurred with a higher prevalence in possums from urban habitat (11.3%) than in possums from woodland habitat (5.6%); however, the host-specific nature of the genotypes may limit spillover infection in the urban setting. This study determined that the coexistence of possums with sympatric populations of humans, pets, and zoo animals in the urban Australian environment is unlikely to present a threat to public health safety.

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

2008-01-01

28

Habitat, density and group size of primates in a Brazilian tropical forest.  

PubMed

Habitats, population densities and group sizes of 5 primate species (Callithrix flaviceps, Callicebus personatus personatus, Cebus apella nigritus, Alouatta fusca clamitans, and Brachyteles arachnoides) were estimated, using the method of repeated transect sampling, in an area of montane pluvial forest in eastern Brazil (Atlantic forest). A. fusca and C. apella had the highest densities in terms of groups and individuals per square kilometer, respectively, while B. arachnoides was least abundant. The highest primate densities were observed in areas of secondary vegetation. Both group sizes and population densities for the 5 species were generally lower at the Reserva Biologica Augusto Ruschi than those reported in other areas of Atlantic forest. Hunting pressure and the different carrying capacity of the habitat are suggested as possible causes for the low number of sightings registered for these species. PMID:8206419

Pinto, L P; Costa, C M; Strier, K B; da Fonseca, G A

1993-01-01

29

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

Microsoft Academic Search

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

LAL Corner; BM Buddle

2005-01-01

30

Integrating population size analysis into habitat suitability assessment: implications for giant panda conservation in the Minshan Mountains, China  

Microsoft Academic Search

Compared to conventional approaches, the integration of population size analysis with habitat suitability assessment on a\\u000a large scale can provide more evidence to explain the mechanisms of habitat isolation and fragmentation, and thus make regional\\u000a conservation plans. In this paper, we analyzed the habitat suitability for giant pandas in the Minshan Mountains, China, using\\u000a the ecological-niche factor analysis (ENFA) method,

Xuezhi Wang; Weihua Xu; Zhiyun Ouyang

2009-01-01

31

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...

32

Desiccation resistance and water balance in southern African keratin beetles (Coleoptera, Trogidae): the influence of body size and habitat  

Microsoft Academic Search

Desiccation resistance and water balance were examined in the adults of seven trogid species, which differed both in body\\u000a size and in the habitats from which they were collected. Body water contents (51–58% fresh mass) and desiccation rates at\\u000a 27?°C (0.00026–0.00093 g?h?1) in these species were very similar to those of unrelated, similar-sized beetles from arid habitats. The keratin beetles

M. D. Le Lagadec; S. L. Chown; C. H. Scholtz

1998-01-01

33

Seedling growth strategies and seed size effects in fourteen oak species native to different soil moisture habitats  

Microsoft Academic Search

Seedling growth and morphology are thought to reflect evolutionary responses to habitat or influences of seed size. To test\\u000a these hypotheses, we selected fourteen species of North American oaks differing in soil moisture habitat preference and seed\\u000a size. Seedlings were grown for 1?–?2 years with abundant soil water and moderate soil nutrition in pots placed outdoors and\\u000a in a common

T. J. Long; R. H. Jones

1996-01-01

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.

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

2013-09-04

36

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

2012-04-30

37

Compensatory immigration depends on adjacent population size and habitat quality but not on landscape connectivity.  

PubMed

1. Populations experiencing localized mortality can recover in the short term by net movement of individuals from adjacent areas, a process called compensatory immigration or spillover. Little is known about the factors influencing the magnitude of compensatory immigration or its impact on source populations. Such information is important for understanding metapopulation dynamics, the use of protected areas for conservation, management of exploited populations and pest control. 2. Using two small, territorial damselfish species (Stegastes diencaeus and S. adustus) in their naturally fragmented habitat, we quantified compensatory immigration in response to localized mortality, assessed its impact on adjacent source populations and examined the importance of potential immigrants, habitat quality and landscape connectivity as limiting factors. On seven experimental sites, we repeatedly removed 15% of the initial population size until none remained and immigration ceased. 3. Immigrants replaced 16-72% of original residents in S. diencaeus and 0-69% in S. adustus. The proportion of the source population that immigrated into depleted areas varied from 9% to 61% in S. diencaeus and from 3% to 21% in S. adustus. In S. diencaeus, compensatory immigration was strongly affected by habitat quality, to a lesser extent by the abundance of potential immigrants and not by landscape connectivity. In S. adustus, immigration was strongly affected by the density of potential migrants and not by habitat quality and landscape connectivity. On two control sites, immigration in the absence of creation of vacancies was extremely rare. 4. Immigration occurred in response to localized mortality and was therefore compensatory. It was highly variable, sometimes producing substantial impacts on both depleted and source populations. The magnitude of compensatory immigration was influenced primarily by the availability of immigrants and by the potential improvement in territory quality that they could achieve by immigrating and not by their ability to reach the depleted area. PMID:22548493

Turgeon, Katrine; Kramer, Donald L

2012-04-30

38

Quantifying Fish Habitat in Streams: Transect Spacing, Sample Size, and a Proposed Framework  

Microsoft Academic Search

Procedures for evaluating fish habitat in streams have focused largely on specific methods used to sample individual habitat variables, and studies ofsampling design are uncommon. We used data from 86 sites on 58 Wisconsin streams to determine the optimal number and spacing of habitat transects needed to characterize the means of commonly measured habitat variables. The optimal number of transects

Timothy D. Simonson; John Lyons; Paul D. Kanehl

1994-01-01

39

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

PubMed

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

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

2012-08-10

40

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.

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

2012-01-01

41

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

42

Forest habitat use and home-range size in radio-collared fallow deer  

Microsoft Academic Search

mature forests and young plantations were least utilised. Diurnal and nocturnal habitat selection patterns differed significantly. The primary difference was the use of mead - ows, which was higher at night than during the day. Results on the representativeness of diurnal habitat use to 24-hour data were equivocal. Although daytime and 24-hour habitat use patterns were similar, day vs. night

Jakub Borkowski

2007-01-01

43

Habitat patch size and isolation as predictors of occupancy and number of argyrodine spider kleptoparasites in Nephila webs.  

PubMed

How fully a suitable habitat patch is utilized by organisms depends crucially on patch size and isolation. Testing this interplay is made difficult in many systems by the arbitrariness of defining a "habitat patch", measuring its boarders, and relatively low detection probability of the inhabitants. Spider webs as habitat patches for obligate web kleptoparasites are free from these problems. Each individual web is a highly discrete and readily measured habitat patch, and the detection probability of argyrodine spider kleptoparasites is very nearly 1. Hence, spider webs emerge as simple systems for ecological models such as patch occupancy and metapopulation biology. Recently, I showed that the distribution of kleptoparasites among host webs relates both to web (patch) size as well as patch connectivity. Here, I test the relative importance of patch size versus isolation in explaining patch occupancy and abundance of inhabitants. I find that (1) web size is the better predictor of patch occupancy and abundance. (2) Web size is overall positively correlated with abundance, but predicts it most precisely among interconnected webs and not at all among the most isolated webs. Hence, patch occupancy and inhabitant abundance is explained by a rather complex interplay between patch size and isolation. PMID:21136246

Agnarsson, Ingi

2010-12-07

44

Habitat selection of two medium-sized carnivores in an isolated and highly anthropogenic Mediterranean park: the importance of riverbank vegetation  

Microsoft Academic Search

Since habitat selection is a key aspect of animal activity, its study in anthropogenic environments could show some clues about how medium-sized carnivores deal with the fact of living in suburban Mediterranean habitats. Compositional analysis was performed to evaluate the habitat selection of foxes and genets in a highly humanized metropolitan park of the NE Iberian Peninsula at population level

G. Molina-Vacas; V. Bonet-Arbolí; J. D. Rodríguez-Teijeiro

2012-01-01

45

Habitat selection of two medium-sized carnivores in an isolated and highly anthropogenic Mediterranean park: the importance of riverbank vegetation  

Microsoft Academic Search

Since habitat selection is a key aspect of animal activity, its study in anthropogenic environments could show some clues about how medium-sized carnivores deal with the fact of living in suburban Mediterranean habitats. Compositional analysis was performed to evaluate the habitat selection of foxes and genets in a highly humanized metropolitan park of the NE Iberian Peninsula at population level

G. Molina-Vacas; V. Bonet-Arbolí; J. D. Rodríguez-Teijeiro

2011-01-01

46

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

PubMed

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

Lönnberg, K; Eriksson, O

2012-10-15

47

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

PubMed

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

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

2009-09-01

48

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

PubMed Central

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

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

2012-01-01

49

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

50

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

2010-12-14

51

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

Microsoft Academic Search

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

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

2006-01-01

52

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

53

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

Microsoft Academic Search

Survival and growth of early fish stages are maximal in coastal and estuarine habitats where natural shallow areas serve as nurseries for a variety of widely distributed species on the continental shelf. Processes occurring in these nursery grounds during the juvenile stage affect growth and may be important in regulating the year-class strength of fishes and population size. The need,

J. Holley; D. Guerault; Y. Desaunay

54

Functional habitat area as a reliable proxy for population size: case study using two butterfly species of conservation concern  

Microsoft Academic Search

Accurate estimates of population size are essential for effective conservation and restoration management of threatened species.\\u000a Nevertheless, reliable methods to estimate population size, such as mark-release-recapture studies (MRR), are time and labour\\u000a consuming and may generate negative impact(s) on both the habitats and organisms studied. This may complicate their use if\\u000a several sites need to be studied concurrently. Consequently, there

Camille TurlureJulie; Julie Choutt; Hans Van Dyck; Michel Baguette; Nicolas Schtickzelle

2010-01-01

55

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

Microsoft Academic Search

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

Per Nyström; Jose R. Pérez

1998-01-01

56

HABITAT PATCH SIZE AND LOCAL DISTRIBUTION OF BURROWING OWLS (ATHENE CUNICULARIA) IN ARGENTINA  

Microsoft Academic Search

Habitat quality and landscape structure are key factors that determine the distributions of ani- mals. The general characteristics of the habitat of Burrowing Owls (Athene cunicularia) have been well stud- ied, but little is known about how landscape structure affects this species. Other studies have suggested that food resources for owls should be higher in small patches because of increased

Diego Villarreal; Marcela Machicote; Lyn C. Branch; Juan José Martinez; Analía Gopar

2005-01-01

57

Connectivity in urbanizing landscapes: The importance of habitat configuration, urban area size, and dispersal  

Microsoft Academic Search

Human activities affect both the amount and configuration of habitat. These changes have important ecological implications\\u000a that can be measured as changes in landscape connectivity. I investigated how urbanization interacts with the initial amount\\u000a and aggregation of habitat to change dispersal potential, restoration potential, and the risk of spatially extensive disturbances.\\u000a I used a factorial set of simulated landscapes and

Britta G. Bierwagen

2007-01-01

58

Purification of secretory immunoglobulin A from milk of the brushtail possum (Trichosurus vulpecula)  

Microsoft Academic Search

AIM: To identify and purify secretory immunoglobulin A (sIgA), a key effecter molecule in mucosal immune responses, from milk of the brushtail possum (Trichosurus vulpecula).METHODS: Milk samples were collected from female possums with pouch young, and clarified by centrifugation and precipitation methods. The clarified fraction was purified by gel filtration and affinity chromatography to yield sIgA. Sodium dodecyl sulphate-polyacrylamide gel

EE Doolin; RG Midwinter; AR McCarthy; BM Buddle

2001-01-01

59

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

60

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

PubMed

Population size and habitat-specific abundance estimates are essential for conservation management. A major impediment to obtaining such estimates is that few statistical models are able to simultaneously account for both spatial variation in abundance and heterogeneity in detection probability, and still be amenable to large-scale applications. The hierarchical distance-sampling model of J. A. Royle, D. K. Dawson, and S. Bates provides a practical solution. Here, we extend this model to estimate habitat-specific abundance and rangewide population size of a bird species of management concern, the Island Scrub-Jay (Aphelocoma insularis), which occurs solely on Santa Cruz Island, California, USA. We surveyed 307 randomly selected, 300 m diameter, point locations throughout the 250-km2 island during October 2008 and April 2009. Population size was estimated to be 2267 (95% CI 1613-3007) and 1705 (1212-2369) during the fall and spring respectively, considerably lower than a previously published but statistically problematic estimate of 12 500. This large discrepancy emphasizes the importance of proper survey design and analysis for obtaining reliable information for management decisions. Jays were most abundant in low-elevation chaparral habitat; the detection function depended primarily on the percent cover of chaparral and forest within count circles. Vegetation change on the island has been dramatic in recent decades, due to release from herbivory following the eradication of feral sheep (Ovis aries) from the majority of the island in the mid-1980s. We applied best-fit fall and spring models of habitat-specific jay abundance to a vegetation map from 1985, and estimated the population size of A. insularis was 1400-1500 at that time. The 20-30% increase in the jay population suggests that the species has benefited from the recovery of native vegetation since sheep removal. Nevertheless, this jay's tiny range and small population size make it vulnerable to natural disasters and to habitat alteration related to climate change. Our results demonstrate that hierarchical distance-sampling models hold promise for estimating population size and spatial density variation at large scales. Our statistical methods have been incorporated into the R package unmarked to facilitate their use by animal ecologists, and we provide annotated code in the Supplement. PMID:23210315

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

2012-10-01

61

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

USGS Publications Warehouse

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

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

2012-01-01

62

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

EPA Science Inventory

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

63

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

64

The effect of egg size and habitat on starling nestling growth and survival  

Microsoft Academic Search

In spite of the fact that hatchling size and energy reserves in birds are affected by egg size, many studies have failed\\u000a to find an effect of egg size on offspring fitness. One possibility is that this is because they have been performed in areas\\u000a with high food availability and that effects of egg size on offspring fitness are most

Henrik G. Smith; Måns Bruun

1998-01-01

65

Marine reserves reduce risk of climate-driven phase shift by reinstating size- and habitat-specific trophic interactions.  

PubMed

Spatial closures in the marine environment are widely accepted as effective conservation and fisheries management tools. Given increasing human-derived stressors acting on marine ecosystems, the need for such effective action is urgently clear. Here we explore mechanisms underlying the utility of marine reserves to reinstate trophic dynamics and to increase resilience of kelp beds against climate-driven phase shift to sea urchin barrens on the rapidly warming Tasmanian east coast. Tethering and tagging experiments were used to examine size- and shelter-specific survival of the range-extending sea urchin Centrostephanus rodgersii (Diadematidae) translocated to reefs inside and outside no-take Tasmanian marine reserves. Results show that survival rates of C. rodgersii exposed on flat reef substratum by tethering were approximately seven times (small urchins 10.1 times; large urchins 6.1 times) lower on protected reef within marine reserve boundaries (high abundance of large predatory-capable lobsters) compared to fished reef (large predatory lobsters absent). When able to seek crevice shelter, tag-resighting models estimated that mortality rates of C. rodgersii were lower overall but remained 3.3 times (small urchins 2.1 times; large urchins 6.4 times) higher in the presence of large lobsters inside marine reserves, with higher survival of small urchins owing to greater access to crevices relative to large urchins. Indeed, shelter was 6.3 times and 3.1 times more important to survival of small and large urchins, respectively, on reserved relative to fished reef. Experimental results corroborate with surveys throughout the range extension region, showing greater occurrence of overgrazing on high-relief rocky habitats where shelter for C. rodgersii is readily available. This shows that ecosystem impacts mediated by range extension of such habitat-modifying organisms will be heterogeneous in space, and that marine systems with a more natural complement of large and thus functional predators, as achievable within no-take reserves, will minimize local risk of phase shifts by reinstating size and habitat-specific predator-prey dynamics eroded by fishing. Importantly, our findings also highlight the crucial need to account for the influence of size dynamics and habitat complexity on rates of key predator-prey interactions when managing expectations of ecosystem-level responses within marine reserve boundaries. PMID:22827131

Ling, S D; Johnson, C R

2012-06-01

66

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

Microsoft Academic Search

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

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

2005-01-01

67

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

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

68

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

Microsoft Academic Search

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

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

2010-01-01

69

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

70

Decline and likely extinction of a northern Australian native rodent, the Brush-tailed Rabbit-rat Conilurus penicillatus  

Microsoft Academic Search

Contemporary fire patterns are considered the most likely cause for regional population decline amongst small to medium mammals in northern tropical Australia. Here we assess the extinction risk faced by a vulnerable north Australian native rodent, the Brush-tailed Rabbit-rat Conilurus penicillatus in relation to fire frequency. This species has recently suffered a significant contraction in range. We provide the first

Ronald S. C. Firth; Barry W. Brook; John C. Z. Woinarski; Damien A. Fordham

2010-01-01

71

Interspecific and seasonal dietary differences of Himalayan thar, chamois and brushtail possums in the central Southern Alps, New Zealand  

Microsoft Academic Search

Himalayan thar or tahr (Hemitragus jemlahicus), Alpine chamois (Rupicapra rupicapra) and brushtail possums (Trichosurus vulpecula) are native to the Himalaya, Europe and Australia, respectively, but are now sympatric in parts of the central Southern Alps, New Zealand. All three species are managed as pests by the Department of Conservation. We analysed the diets of 246 thar, 78 chamois and 113

John P. Parkes; David M. Forsyth

2008-01-01

72

Aerosol vaccination of the brushtail possum ( Trichosurus vulpecula) with bacille Calmette–Guérin: the duration of protection  

Microsoft Academic Search

Bovine tuberculosis is endemic in wild brushtail possums (Trichosurus vulpecula) in New Zealand. The disease is controlled by reducing or eliminating infected possum populations, but control methods do not kill all possums in the targeted area, leaving some tuberculous possums to maintain the disease. Vaccination with bacille Calmette–Guérin (BCG) has been shown to provide significant levels of protection. Vaccination is

L. A. L Corner; B. M Buddle; D. U Pfeiffer; R. S Morris

2001-01-01

73

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

74

Molecular and functional characterization of the cystic fibrosis transmembrane conductance regulator from the Australian common brushtail possum, Trichosurus vulpecula  

Microsoft Academic Search

Unlike eutherian mammals, the colon of the Australian common brushtail possum, Trichosurus vulpecula, a metatherian mammal, is incapable of electrogenic Cl? secretion and has elevated levels of electrogenic Na+ absorption, while the ileum secretes HCO3? rather than Cl?. In eutherian mammals, the cystic fibrosis transmembrane conductance regulator (CFTR) is essential for both Cl? and HCO3? secretion and the regulation of

K. J. Demmers; D. Carter; S. Fan; P. Mao; N. J. Maqbool; B. J. McLeod; R. Bartolo; A. G. Butt

2010-01-01

75

Digestion and metabolism of high-tannin Eucalyptus foliage by the brushtail possum ( Trichosurus vulpecula ) (Marsupialia: Phalangeridae)  

Microsoft Academic Search

The digestion and metabolism ofEucalyptus melliodora foliage was studied in captive brushtail possums (Trichosurus vulpecula). The foliage was low in nitrogen and silica but high in lignified fibre and phenolics compared with diets consumed by most other herbivores. The high lignin content was suggested as the main cause of the low digestibility ofE. melliodora cell walls (24%); microscopic observations of

W. J. Foley; I. D. Hume

1987-01-01

76

Secondary metabolites in Eucalyptus melliodora: field distribution and laboratory feeding choices by a generalist herbivore, the common brushtail possum  

Microsoft Academic Search

We studied the influence of a group of plant secondary compounds, the sideroxylonals, on feeding by the common brushtail possum (Trichosurus vulpecula), a generalist herbivore. Possums were offered synthetic diets either with or without sideroxylonals or, in separate experiments, foliage from 28 individual Eucalyptus melliodora trees. Possums ate less of the synthetic diet at sideroxylonal concentrations of 4 and 7

I. R. WallisA; M. L. Watson; W. J. Foley

2002-01-01

77

Immunocontraception of Eastern Grey kangaroos (Macropus giganteus) with recombinant brushtail possum (Trichosurus vulpecula) ZP3 protein.  

PubMed

This study examined the potential of a recombinant marsupial zona pellucida 3 protein as a contraceptive vaccine for the Eastern Grey kangaroo, a marsupial that is locally overabundant in several regions of eastern Australia. First, a pilot study using porcine zona pellucidae (PZP) demonstrated that ZP proteins, primarily the ZP3 component of PZP, are highly immunogenic in the grey kangaroo and produce a long-lasting humoral response to a single immunisation, as found in other marsupials. Immunisation with 300 microg of a non-glycosylated recombinant brushtail possum ZP3 (recBP-ZP3) protein in complete Freund's adjuvant produced a similar, significant and sustained antibody response, and none of the immunised kangaroos (n=7) produced offspring during the following breeding season compared with four out of the six control animals. An epitope analysis of the B-cell response to recBP-ZP3 using a brushtail possum ZP3 identified numerous B-cell epitope regions clustered around the N- and C-terminal regions of the protein. Two regions of interest for further fertility vaccine development based on their immunogenicity and fertility trials and functional studies in other species were found to be immunogenic. These results suggest that immunocontraception based on targeting the ZP3 protein within the zona pellucida may be an effective strategy for fertility reduction in Eastern Grey kangaroos. PMID:19215986

Kitchener, Anne L; Harman, Amanda; Kay, David J; McCartney, Carmen A; Mate, Karen E; Rodger, John C

2009-02-11

78

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

Microsoft Academic Search

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

Nina Eschweiler; Markus Molis; Christian Buschbaum

2009-01-01

79

Effect of oestradiol treatment on mast cell populations and microflora in the vaginal cul-de-sac of seasonally anoestrous brushtail possums (Trichosurus vulpecula)  

Microsoft Academic Search

Mast cell populations in the vaginal cul-de-sac of female brushtail possums do not appear to be related to microbial invasion but changes in their density occur at oestrus, indicating a hormonal influence. The present study examined the effect of treatment with oestradiol on microflora and on mast cell numbers and their spatial location in cul-de-sac tissue of seasonally anoestrous brushtail

P. M. Mahoney; P. R. Hurst; B. J. McLeod; M. A. McConnell; E. G. Thompson

2003-01-01

80

Small local population sizes and high habitat patch fidelity in a specialised solitary bee  

Microsoft Academic Search

Andrena hattorfiana is a rare solitary bee which has declined during the last decades throughout western Europe. It is specialised to forage\\u000a pollen from plants of the family Dipsacaceae. Knowledge of distribution, dispersal propensity, and local population sizes\\u000a is essential for successful conservation of A. hattorfiana. The investigated local bee populations (n = 78) were dominated by small local populations and 60% were

Markus Franzén; Magnus Larsson; Sven G. Nilsson

2009-01-01

81

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

NASA Astrophysics Data System (ADS)

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

Eschweiler, Nina; Molis, Markus; Buschbaum, Christian

2009-06-01

82

Habitat structure effects on size selection of snail kites ( Rostrhamus sociabilis ) and limpkins ( Aramus guarauna ) when feeding on apple snails ( Pomacea spp.)  

NASA Astrophysics Data System (ADS)

Consumer density can influence foraging patterns such as prey-size selection, but few studies have evaluated its effects in field conditions. Here we evaluate the hypothesis that habitat structure influences forager density, and that this in turn influences the size of prey consumed by two avian predators. The sizes of two apple snail species available to, and consumed by, snail kites and limpkins were determined at sites with high and low densities of snail kite foraging perches. Sites with more perches had higher densities of snail kites, but not of limpkins. Both predators consumed prey larger than those available in the marshes, but habitat structure influenced the probability of consumption of different prey sizes. Limpkins consumed larger prey at low-density sites when compared with high-density sites, in contrast to other studies that found no size selection. Thus, limpkins can present prey-size selectivity but the presence of other predators can influence the range of prey sizes consumed. When a wider range of prey sizes is available, limpkins can select larger prey; alternatively, higher densities of other predators can result in higher foraging risk, favoring the capture of smaller, easier to handle prey. Snail kites incorporated smaller prey to their diet at low-density sites than at high-density ones, probably due to the higher costs of carrying large prey, differential age distribution, or lower foraging risks. Thus, habitat structure can influence consumer density and foraging patterns in complex ways, influencing predator-prey interactions in natural systems.

Tanaka, Marcel O.; Souza, Andréa L. T.; Módena, Érica S.

2006-07-01

83

Characterisation of antisera to recombinant IgA of the common brushtail possum (Trichosurus vulpecula).  

PubMed

One of the limiting factors in understanding immune responses in marsupials is the scarcity of marsupial specific immunological reagents. This paper describes the characterisation of an antiserum raised against a recombinant protein of the constant region of the heavy chain of IgA (C(alpha)) of the common brushtail possum (Trichosurus vulpecula). The availability of a marsupial specific anti-IgA provides a useful tool for the characterisation of mucosal immune responses in possums. Anti-C(alpha) specifically detects IgA in possum serum and secretions using ELISAs, immuno-dot blots and Western blots without any cross-reactivity to IgG. The possum anti-C(alpha) cross-reacts with IgA of koala (Phascolarctos cinereus), tammar wallaby (Macropus eugenii) and eastern grey kangaroo (Macropus giganteus), demonstrating the potential for use in other marsupials. PMID:12088648

Rawson, Renée R; Belov, Katherine; Gidley-Baird, A Angus; Cooper, Desmond W

2002-09-01

84

Size-related habitat use and schooling behavior in two species of surgeonfish (Acanthurus bahianus and A. coeruleus) on a fringing reef in Barbados, West Indies  

Microsoft Academic Search

Surgeonfish (Acanthuridae) are prominent, herbivorous members of coral reef communities that occur as dispersed individuals and small, loose groups ('non-schooling fish') or as members of large, highly aggregated, mixed-species schools ('schooling fish'). We examined the relationships among fish size, habitat use and schooling in two species of surgeonfish on a fringing reef in Barbados, West Indies. Both ocean surgeonfish, Acanthurus

Gareth L. Lawson; Donald L. Kramer; Wayne Hunte

1999-01-01

85

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

86

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

PubMed

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

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

2009-07-01

87

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

Microsoft Academic Search

Field surveys and laboratory studies were used to determine the role of substrata in habitat selection by young-of-the year winter flounder. A synoptic field survey of winter flounder and sediments in the Navesink River–Sandy Hook Bay estuarine system in New Jersey demonstrated that winter flounder distribution was related to sediment grain size. Analysis using a generalized additive model indicated that

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

2001-01-01

88

Field observations of the alarm response to crushed conspecifics in the freshwater snail Pomacea canaliculata : effects of habitat, vegetation, and body size  

Microsoft Academic Search

The freshwater snail Pomacea canaliculata shows alarm responses to chemical cues released from injured conspecifics, but its behavioural responses in the field are\\u000a unknown. We investigated effects of habitat (canals or paddy fields), vegetation, and body size on alarm responses in the\\u000a field. Snails responded to crushed conspecifics within 4 min by burying themselves, but the proportions of self-buried snails\\u000a were

Kahori Aizaki; Yoichi Yusa

2009-01-01

89

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.

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

2009-01-01

90

Comparisons between the influences of habitat, body size and season on the dietary composition of the sparid Acanthopagrus latus in a large marine embayment  

NASA Astrophysics Data System (ADS)

Seasonal samples from Shark Bay on the west coast of Australia were used to determine (1) the habitats occupied by the juveniles and adults of Acanthopagrus latus in this large subtropical marine embayment and (2) the extent to which the dietary composition of this sparid is influenced by habitat type, body length and season. Sampling was undertaken in two habitat types in which A. latus was known to be abundant, namely mangrove (Avicennia marina) creeks and nearby rocky areas, the latter comprising sandstone boulders and/or limestone reefs. The mean total length ±95% CLs of A. latus was far lower in mangrove creeks, 126 ± 6.1 mm, than in rocky areas, 313 ± 4.7 mm. As A. latus attains maturity at ca. 245 mm, the juveniles of this species typically occupy mangrove areas and then, with increasing body size, move to nearshore rocky areas, where they become adults. The species composition of the food ingested by juvenile A. latus in mangrove creeks differed markedly from that of large juveniles and adults in rocky areas. Based on analyses of data for both habitat types combined, this difference was far greater than that between size classes and season, which was negligible. There were indications, however, that, overall within each habitat, the dietary composition did change seasonally, although not with body size. Acanthopagrus latus fed predominantly on mangrove material, sesarmid crabs and small gastropods in mangrove habitats, and mainly on Brachidontes ustulatus in rocky areas, where this mytilid bivalve is very abundant. The mangrove material, which contributed nearly 40% of its overall dietary volume in mangrove creeks, consisted mainly of lateral root primordia. This apparently unique food source for a teleost is presumably ingested through subsurface nipping, which would be facilitated by the mouth and dentitional characteristics of sparids. The almost total lack of correspondence in the dietary compositions of fish in the length class that was well represented in both mangrove and rocky areas illustrates the extent to which this sparid is capable of opportunistic feeding behaviour.

Platell, M. E.; Ang, H. P.; Hesp, S. A.; Potter, I. C.

2007-05-01

91

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

PubMed

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

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

2001-03-15

92

Size-dependent habitat choice in Daphnia galeata Sars and size-structured interactions among zooplankton in a subarctic lake (lake Lombola, Norway)  

Microsoft Academic Search

Seasonal changes in vertical distribution of Daphnia galeata and other zooplankters were monitored in lake Lombola (69° 07? N). Depth-habitat use, availability of edible algae and zooplankton densities were recorded to examine seasonal changes in intensity of competition between Daphnia and the other herbivores in the lake. Early in July, the exephippial generation of Daphnia aggregated near the surface, independently

Raul Primicerio

2003-01-01

93

The effect of small-size habitat disturbances on population density and time to extinction of the prairie vole  

Microsoft Academic Search

We present a study, based on simulations with SERDYCA, a spatially-explicit individual-based model of rodent dynamics, on the relation between population persistence and the presence of numerous isolated disturbances in the habitat. We are specifically interested in the effect of disturbances that do not fragment the environment on population persistence. Our results suggest that the presence of disturbances in the

Tanya Kostova; Tina Carlsen

2005-01-01

94

Interspecific variation in desiccation survival time of Aedes (Stegomyia) mosquito eggs is correlated with habitat and egg size  

Microsoft Academic Search

Survival times of eggs under three humidity conditions (42%, 68%, 88% RH) were investigated among Aedes (Stegomyia) mosquitoes from temperate and tropical zones (5 species and 20 geographical strains). This subgenus tends to occupy small aquatic sites as larvae, where desiccation resistance of eggs is necessary during habitat drought. Interspecific comparison showed that the egg survival time was correlated with

T. Sota; M. Mogi

1992-01-01

95

Vaccination of the brushtail possum ( Trichosurus vulpecula) against Mycobacterium bovis infection with bacille Calmette-Guérin: the response to multiple doses  

Microsoft Academic Search

In New Zealand, the brushtail possum (Trichosurus vulpecula) is the principal wildlife vector of bovine tuberculosis. Control of infected possum populations contributes to the control of tuberculosis in domestic livestock. Vaccination is potentially a complementary strategy to population control, but to be cost-effective, administration of the vaccine to possums would need to be from an appropriately designed automatic vaccinator. Possums

L. A. L. Corner; B. M. Buddle; D. U. Pfeiffer; R. S. Morris

2002-01-01

96

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

97

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

2005-12-18

98

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

PubMed

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

Delgado-Acevedo, Johanna; Restrepo, Carla

2008-05-09

99

The Effect of Small-Size Habitat Disturbances on Population Density and Time to Extinction of the Prairie Vole  

SciTech Connect

We present a study, based on simulations with SERDYCA, a spatially-explicit individual-based model of rodent dynamics, on the relation between population persistence and the presence of numerous isolated disturbances in the habitat. We are specifically interested in the effect of disturbances that do not fragment the environment on population persistence. Our results suggest that the presence of disturbances in the absence of fragmentation can actually increase the average time to extinction of the modeled population. The presence of disturbances decreases population density but can increase the chance for mating in monogamous species and consequently, the ratio of juveniles in the population. It thus provides a better chance for the population to restore itself after a severe period with critically low population density. We call this the ''disturbance-forced localization effect''.

Kostova, T; Carlsen, T

2004-12-13

100

Size and shape variation in a Lesser Antillean anole, Anolis oculatus (Sauria: Iguanidae) in relation to habitat  

Microsoft Academic Search

The anole fauna of the Lesser Antilles is depauperate in relation to that of the Greater Antilles, where complex communities characterized by adaptive specialization and convergent structure are present. Much of this adaptation is the result of changes in body size and shape, probably as a result of interspecific competition. Here we present data on variation in size and shape

ANITA MALHOTRA; ROGER S. THORPE

1997-01-01

101

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

102

Influence of seagrass habitat patch size on growth and survival of juvenile bay scallops, Argopecten irradians concentricus (Say)  

Microsoft Academic Search

Patchy seagrass meadows are common features on high energy sand shoals in temperate coastal waters. We tested the effect of seagrass patch size within patchy seagrass meadows on growth and survival of juvenile bay scallops, Argopecten irradians concentricus (Say), during spring (two sites) and fall (one site) settlement periods in Back Sound, North Carolina, USA. Because plant characteristics such as

Elizabeth A Irlandi; Beth A Orlando; William G Ambrose

1999-01-01

103

The ploys of sex: relationships among the mode of reproduction, body size and habitats of coral-reef brittlestars  

NASA Astrophysics Data System (ADS)

Observations were made of 33 species of brittlestars (3980 specimens) from specific substrata collected in four zones on the Belize Barrier Reef, Caribbean Sea. The body size of most species of brittlestars with planktonic larvae differs significantly among different substrata. Generally, individuals from the calcareous alga Halimeda opuntia are smallest, those found in corals ( Porites porites, Madracis mirabilis, and Agaricia tenuifolia) are larger, and those from coral rubble are the largest. This suggests that brittlestars with planktonic larvae move to new microhabitats as they grow. In contrast, most brooding and fissiparous species are relatively small and their size-distributions are similar among all substrata. Halimeda harbours denser concentrations of brittlestars and more small and juvenile individuals than the other substrata. Juveniles of the brooding and fissiparous species are most common in Halimeda on the Back Reef whereas juveniles developing from planktonic larvae are most common in Halimeda patches in deeper water. Fissiparity and brooding may be means for individuals (genomes) of small, apomictic species to reach large size (and correspondingly high fecundities) in patchy microhabitats that select for small body sizes. Small brittlestar species and juveniles are most numerous in the microhabitats called refuge-substrata, such as Halimeda, which may repel predators and reduce environmental stress. Whether young brittlestars are concentrated in refuge-substrata through settlement behavior, migration, or differential survival remains unknown. Experiments revealed that coral polyps kill small brittlestars, perhaps accounting for the rarity of small and juvenile brittlestars in coral substrata.

Hendler, Gordon; Littman, Barbara S.

1986-08-01

104

Expression of mRNA encoding growth differentiation factor 9 and bone morphogenetic protein 15 during follicular formation and growth in a marsupial, the brushtail possum ( Trichosurus vulpecula)  

Microsoft Academic Search

The oocyte derived growth differentiation factor (GDF) 9 and bone morphogenetic protein 15 (BMP15; also known as GDF9b) are essential for normal follicular growth. However, little is known about expression of these factors during ovarian development. Therefore, we determined the ontogeny of expression of GDF9 and BMP15 mRNA in the developing ovary of the brushtail possum. Ovaries were collected from

Douglas C Eckery; Lisa J Whale; Stephen B Lawrence; Katherine A Wylde; Kenneth P McNatty; Jennifer L Juengel

2002-01-01

105

Oral vaccination of brushtail possums with BCG: Investigation into factors that may influence vaccine efficacy and determination of duration of protection  

Microsoft Academic Search

AIMS: To determine factors that may influence the efficacy of an oral pelleted vaccine containing Mycobacterium bovis bacille Calmette-Guérin (BCG) to induce protection of brushtail possums against tuberculosis. To determine the duration of protective immunity following oral administration of BCG.METHODS: In Study 1, a group of possums (n=7) was immunised by feeding 10 pellets containing dead Pasteur BCG, followed 15

BM Buddle; FE Aldwell; DL Keen; NA Parlane; KL Hamel; GW de Lisle

2006-01-01

106

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

107

Habitat fragmentation and population size of the black and gold howler monkey (Alouatta caraya) in a semideciduous forest in Northern Argentina.  

PubMed

A population of black and gold howler monkeys (Alouatta caraya) living near the southern limit of its distribution in a semideciduous forest located in northern Argentina was studied in 2003 to evaluate the possible effects of habitat fragmentation - owing to logging - on its density and social organization within it. Aerial photographs taken in 1982, 1992, and 2001 were used to compare maps of vegetation. These maps were used to evaluate changes in the area covered by forest fragments. From March to June 2003, 10-day monthly surveys of howlers were made in each fragment. A total of 232 individual howlers were counted, belonging to 34 groups plus a solitary adult female. Groups ranged from 2 to 19 individuals (mean = 6.82, SD = 4.23), and 21% of the groups contained more than one adult male. Adults accounted for 55% of the individuals, immatures for 45%, and infants represented 13% of the total. Data obtained were compared with information available for the same population for 1982 and 1995. Results revealed no significant changes in the area of fragments, the crude and ecological density of howlers, and group composition. Group sizes and group composition of howlers suggest that the population remained stable over the past 22 years. The density, number of groups, and individuals appears not to be affected by fragmentation and logging, but crude density was low compared with other less-disturbed habitats. The status of the population remains uncertain owing to isolation, and because there are no protected areas to ensure its stability for the future. PMID:17358009

Zunino, Gabriel E; Kowalewski, Martin M; Oklander, Luciana I; González, Viridiana

2007-09-01

108

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

NASA Astrophysics Data System (ADS)

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

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

1999-02-01

109

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

110

Lysine and glutamate transport in the erythrocytes of common brushtail possum, Tammar Wallaby and eastern grey, kangaroo.  

PubMed

It was recently coincidentally discovered, using 1H NMR spectroscopy, that the erythrocytes of two species of Australian marsupials, Tammar Wallaby (Macropus eugenii) and Bettong (Bettongia penicillata), contain relatively high concentrations of the essential amino acid lysine (Agar NS, Rae CD, Chapman BE, Kuchel PW. Comp Biochem Physiol 1991;99B:575-97). Hence, in the present work the rates of transport of lysine into the erythrocytes from the Common Brushtail Possum (Dactylopsilia trivirgata) and Eastern Grey Kangaroo (Macropus giganteus) (which both have low lysine concentrations), and Tammar Wallaby were studied, to explore the mechanistic basis of this finding. The concentration-dependence of the uptake was studied with lysine alone and in the presence of arginine, which may be a competitor of the transport in some species. In relation to GSH metabolism, glutamate uptake was determined in the presence and absence of Na+. The data was analysed to yield estimates of the maximal velocity (Vmax) and the Km in each of the species. Erythrocytes from Tammar Wallaby lacked saturable lysine transport in contrast to the other two species. The glutamate uptake was normal in all three animals for adequate GSH biosynthesis. PMID:9773487

Ogawa, E; Kuchel, P W; Agar, N S

1998-04-01

111

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

2005-03-29

112

Freshwater Habitats  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. Students conduct research by sampling organisms in a nearby freshwater habitat to determine how an organism's behavior and adaptation relate to its habitat, and how freshwater habitats have different characteristics depending on whether water is still or moving. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

113

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.

114

Quantifying habitat complexity in aquatic ecosystems  

Microsoft Academic Search

SUMMARY 1. Many aquatic studies have attempted to relate biological features, such as species diversity, abundance, brain size and behaviour, to measures of habitat complexity. Previous measures of habitat complexity have ranged from simple, habitat-specific variables, such as the number of twigs in a stream, to quantitative parameters of surface topography, such as rugosity. 2. We present a new video-based

CAROLY A. S HUMWAY; H ANS A. H OFMANN

2007-01-01

115

WILDLIFE HABITAT  

EPA Science Inventory

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

116

Vaccination of brushtail possums, Trichosurus vulpecula, with Bacille Calmette–Guerin induces T lymphocytes that reduce Mycobacterium bovis replication in alveolar macrophages via a contact-dependent\\/nitric oxide-independent mechanism  

Microsoft Academic Search

The permissiveness of alveolar macrophages from brushtail possums for the replication of Mycobacterium bovis was examined. Mycobacterium bovis replication was indirectly measured by assessing bacterial metabolism via the incorporation of [3-H]-uracil by bacilli released from lysed macrophages previously infected with mycobacteria. Alveolar macrophages allowed substantial replication of virulent M. bovis, in contrast to Bacille Calmette–Guerin (BCG) Pasteur, which replicated poorly.

Michel Denis; D Neil Wedlock; Bryce M Buddle

2005-01-01

117

Urban Habitats  

NSDL National Science Digital Library

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

118

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

119

The Habitat Connection.  

ERIC Educational Resources Information Center

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

Naturescope, 1987

1987-01-01

120

The Habitat Connection.  

ERIC Educational Resources Information Center

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

Naturescope, 1987

1987-01-01

121

Space size relative to prey width and total cover in an area both influence the habitat choices of freshwater angelfish Pterophyllum scalare in mesocosms  

Microsoft Academic Search

Prey survivorship can vary with average space size\\/prey width (Sp\\/Py) and total cover within an area (Ct\\/At). Hypotheses predict that prey survivorship is maximized at intermediate Sp\\/Py values and that prey survivorship increases rapidly from zero to low cover but increases at a slower rate as cover increases further. Freshwater angelfish Pterophyllum scalare made choices between artificial vegetation treatments consistent

Aaron Bartholomew

2012-01-01

122

Effects of Fish Size, Habitat, Flow, and Density on Capture Probabilities of Age0 Rainbow Trout Estimated from Electrofishing at Discrete Sites in a Large River  

Microsoft Academic Search

We estimated size-specific capture probabilities of age-0 rainbow trout Oncorhynchus mykiss in the Lee's Ferry Reach of the Colorado River, Arizona, by backpack and boat electrofishing at discrete shoreline sites using both depletion and mark-recapture experiments. Our objectives were to evaluate the feasibility of estimating capture probability for juvenile fish in larger rivers; to determine how it is influenced by

Josh Korman; Mike Yard; Carl Walters; Lewis G. Coggins

2009-01-01

123

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

124

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.

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

2007-01-01

125

Inhibition of cytochrome P450 enzymes in the Australian brushtail possum, Trichosurus vulpecula: comparison with that of the rat, rabbit, sheep and chicken.  

PubMed

A comparative study was conducted of the inhibition of liver microsomal cytochrome P450 phase I biotransformation enzyme activity of the Australian brushtail possum, rat, rabbit, sheep and chicken. The possum has caused considerable agricultural and ecological problems since its introduction to New Zealand. This work investigated species differences in cytochrome P450 inhibition by selected imidazole derivatives that may be exploited for designing a more species-specific method of toxicological control of the New Zealand possum population. The imidazole derivatives used were ketoconazole, clotrimazole, miconazole and cimetidine. The potency of these inhibitors varied, with clotrimazole and miconazole being most potent, followed by ketoconazole. Cimetidine was the least effective inhibitor. The inhibitory effect of imidazole derivatives on cytochrome p450 phase I biotransformation enzymes appeared more effective in the possum than in other species. All inhibitors used produced type II spectra upon interaction with cytochrome P450 preparations. Possum and chicken microsomal preparations showed absorbancy maxima at 428 nm, rabbit and rat and 429 nm, and sheep at 431 nm. PMID:9682405

Olkowski, A; Gooneratne, R; Eason, C

1998-08-01

126

Predicting future threats to biodiversity from habitat selection by humans  

Microsoft Academic Search

ABSTRACT Global biodiversity is threatened by the human use, alteration and destruction of habitat. The distribution of humans among habitats should, as in other animals, be governed by density- dependent feedback on fitness. It should be possible, therefore, to merge human habitat selection – and, perhaps, other adaptive behaviours – with projections of human population size to forecast,future threats to

Douglas W. morris; Steven R. Kingston

127

Predator-mediated habitat use: some consequences for species interactions  

Microsoft Academic Search

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

Gary Mittelbach

1986-01-01

128

Great Lakes wetlands as amphibian habitats: A review  

Microsoft Academic Search

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

S. J. Hecnar

2004-01-01

129

Rocky Intertidal Habitats  

NSDL National Science Digital Library

Comprehensive text reference describes rocky intertidal habitats and their biological diversity, distribution patterns, temporal changes, links to other habitats and assemblages, and management issues. Supporting materials include photos, tables, figures, and in-text definitions.

130

MODELING PHYSICAL HABITAT PARAMETERS  

EPA Science Inventory

Salmonid populations can be affected by alterations in stream physical habitat. Fish productivity is determined by the stream's physical habitat structure ( channel form, substrate distribution, riparian vegetation), water quality, flow regime and inputs from the watershed (sedim...

131

Mule Deer Habitat Guidelines.  

National Technical Information Service (NTIS)

The purpose of this Mule Deer (Odocoileus hemionus) Habitat Management Guide is principally to assist BLM managers and biologists in planning for and managing mule deer habitat on public lands administered by the Bureau of Land Management. For many years ...

R. M. Kerr

1982-01-01

132

Mortality rate and gross pathology due to tuberculosis in wild brushtail possums (Trichosurus vulpecula) following low dose subcutaneous injection of Mycobacterium bovis.  

PubMed

Gross pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This pathology involves lymphadenomegaly and development of gross lesions in peripheral lymph nodes, with subsequent gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with <50 CFU of M. bovis, then fitted with mortality signal emitting radio tracking collars, released and re-tracked for 6 months. Possum survival probability was 89% up to 12 weeks post-injection (p.i.), but cumulative mortality was rapid from then on. The median survival period, based on study of 38 possums, was 18 weeks p.i.; this corresponds with a predicted time interval of 11 weeks between first presentation of TB as palpable lymphadenomegaly and death for an average possum, shorter than period values currently used in possum TB epidemiological modelling. We also examined gross pathology in 11 possums by post mortem necropsy, and confirmed lymphadenomegaly and tuberculous lesions at 7 and 12 weeks p.i. Extra-peripheral gross lesions were more frequent among possums at 12 weeks p.i. than at 7 weeks, while the occurrence of lung lesions (the most likely cause of disease-induced mortality) was apparent in animals at 12 weeks but not at 7 weeks p.i. Our results suggest that the time course of TB from development of gross lesions to mortality may be shorter than previously estimated from field studies of naturally tuberculous possums. PMID:23063260

Nugent, Graham; Yockney, Ivor; Whitford, Jackie; Cross, Martin L

2012-10-11

133

The organization and connections of somatosensory cortex in the brush-tailed possum (Trichosurus vulpecula): evidence for multiple, topographically organized and interconnected representations in an Australian marsupial.  

PubMed

Microelectrode mapping techniques were used to determine the organization of somatosensory cortex in the Australian brush-tailed possum (Trichosurus vulpecula). The results of electrophysiological mapping were combined with data on the cyto- and myeloarchitecture, and patterns of corticocortical connections, using sections cut tangential to the pial surface. We found evidence for three topographically organized representations of the body surface that were coextensive with architectonic subdivisions. A large, discontinuous cutaneous representation in anterior parietal cortex was termed the primary somatosensory area (SI). Lateral to SI we found evidence for two further areas, the second somatosensory area (SII) and the parietal ventral area (PV). While neurones in all of these areas were responsive to cutaneous stimulation, those of SI were non-habituating, whereas those in SII and PV often habituated to the stimuli. Moreover, neuronal receptive fields in SII and PV were, in general, larger than those in SI. Neurones in cortex adjacent to the rostral and caudal boundaries of SI, including cortex that interdigitated between the discontinuous SI head and body representations, required stimulation of deep receptors in the periphery to elicit responses. Within the region of cortex containing neurones responsive to stimulation of deep receptors, body parts were represented in a mediolateral progression. Injections of anatomical tracers placed in electrophysiologically identified locations in SI revealed ipsilateral connections with other parts of SI, as well as cortex rostral to, caudal to, and interdigitating between, SI. Injections in SI also resulted in labelling in PV, SII, motor cortex, posterior parietal cortex and perirhinal cortex. The patterns of contralateral projections reflected those of ipsilateral projections, although they were relatively less dense. The present findings support recent observations in other marsupials in which multiple representations of the body surface were described, and suggest that multiple interconnected sensory representations may be a common feature of cortical organization and function in marsupials. PMID:10632029

Elston, G N; Manger, P R

1999-01-01

134

Effects of diaspirin cross-linked hemoglobin on motor function of the duodenum and biliary system in the Australian brush-tailed possum in vivo.  

PubMed

Chemically altered hemoglobin-based oxygen carriers have been developed as prototype blood substitutes. Such molecules may affect numerous biological processes, since free hemoglobin scavenges nitric oxide (NO). Diaspirin cross-linked hemoglobin (DCLHb) is a chemically cross-linked molecule, which has a pressor effect on blood pressure, mainly mediated by NO scavenging. However, the effects of DCLHb on the gastrointestinal and biliary motility have not been reported. This study was conducted to investigate the effects of DCLHb on the duodenal and biliary motility and determine if the underlying mechanism involves a NO pathway. Blood pressure, duodenal, sphincter of Oddi and gallbladder motility and trans-sphincteric flow were recorded in anesthetized Australian Brush-tailed possums. The effects of intravenously administered DCLHb (10% solution) or oncotically matched human serum albumin (HSA) solution on these parameters were investigated. To determine the involvement of a NO-mediated pathway in these effects, animals were pretreated with N(omega)-nitro-L-arginine methyl ester (L-NAME) before DCLHb or HSA was given. DCLHb increased blood pressure and duodenal contraction frequency and slowed trans-sphincteric flow compared with the HSA control. The effects of DCLHb on blood pressure and trans-sphincteric flow were immediate and transient, whereas the effect on duodenal contraction frequency was delayed and long-lived. Pretreatment with L-NAME alone increased blood pressure and duodenal contraction frequency and slowed trans-sphincteric flow. DCLHb-induced changes were not evident in the presence of L-NAME. These findings suggest that DCLHb affects duodenal and trans-sphincteric flow predominantly by NO scavenging. PMID:11181942

Konomi, H; Woods, C M; Meedeniya, A C; Giles, L C; Toouli, J; Saccone, G T

2001-03-01

135

Habitat evaluation using GIS  

Microsoft Academic Search

Concern over the fate of plant and animal species throughout the world has accelerated over recent decades. Habitat loss is considered the main culprit in reducing many species’ abundance and range, leading to numerous efforts to plan and manage habitat preservation. Our work uses Geographic Information Systems (GIS) data and modeling to define a spatially explicit analysis of habitat value,

Ross Gerrard; Peter Stine; Richard Church; Michael Gilpin

2001-01-01

136

Uninhabited Habitats on Mars  

Microsoft Academic Search

Investigations of Mars as a potential location for life often make the assumption that where there are habitats, they will contain organisms. However, the observation of the ubiquitous distribution of life in habitable environments on the Earth does not imply the presence of life in Martian habitats. Although uninhabited habitats are extremely rare on the Earth, a lack of a

Charles S. Cockell; Matt Balme; John C. Bridges; Alfonso Davila; Susanne P. Schwenzer

137

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...

138

Patchy Reaction?Diffusion and Population Abundance: The Relative Importance of Habitat Amount and Arrangement  

Microsoft Academic Search

A discrete reaction-diffusion model was used to estimate long-term equilibrium populations of a hypothetical species inhab- iting patchy landscapes to examine the relative importance of habitat amount and arrangement in explaining population size. When ex- amined over a broad range of habitat amounts and arrangements, population size was largely determined by a pure amount effect (pro- portion of habitat in

Michael Bevers

2002-01-01

139

India Habitat Centre  

NSDL National Science Digital Library

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

140

Uninhabited habitats on Mars  

NASA Astrophysics Data System (ADS)

Investigations of Mars as a potential location for life often make the assumption that where there are habitats, they will contain organisms. However, the observation of the ubiquitous distribution of life in habitable environments on the Earth does not imply the presence of life in martian habitats. Although uninhabited habitats are extremely rare on the Earth, a lack of a productive photosynthetic biosphere on Mars to generate organic carbon and oxygen, thus providing a rapidly available redox couple for energy acquisition by life and/or a lack of connectivity between habitats potentially increases the scope and abundance of uninhabited habitats for much of the geological history of the planet. Uninhabited habitats could have existed on Mars from the Noachian to the present-day in impact hydrothermal systems, megaflood systems, lacustrine environments, transient melted permafrost, gullies and local regions of volcanic activity; and there may be evidence for them in martian meteorites. Uninhabited habitats would provide control habitats to investigate the role of biology in planetary-scale geochemical processes on the Earth and they would provide new constraints on the habitability of Mars. Future robotic craft and samples returned from Mars will be able to directly show if uninhabited habitats exist or existed on Mars.

Cockell, Charles S.; Balme, Matt; Bridges, John C.; Davila, Alfonso; Schwenzer, Susanne P.

2012-01-01

141

Habitat Specialization in Tropical Continental Shelf Demersal Fish Assemblages  

PubMed Central

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

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

2012-01-01

142

Schoolyard Habitat Project Guide.  

ERIC Educational Resources Information Center

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

Mason, Rich

143

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

144

Underwater Habitats for Scientific Research in the Great Lakes.  

National Technical Information Service (NTIS)

University of Michigan scientists utilized the SUBLIMNOS underwater habitat for conducting a series of projects to aid in evaluating the potential use of a small sized habitat as a tool for scientific research. The projects were carried out in Little Dunk...

L. H. Somers R. F. Anderson

1970-01-01

145

Habitat and ecology of Nephrops norvegicus.  

PubMed

This review summarizes the data on habitat, population ecology and ecosystem roles of Nephrops norvegicus. The species has a broad range in the northeast Atlantic and Mediterranean, although it is possible that small or isolated patches of suitable habitat may not be occupied due to restrictions on larval supply. Nephrops densities are related to the silt-clay content of sediments, with interactions between habitat quality and density indicating competition for resources. An analysis of density-size interactions across fishery functional management units (FUs) suggests that growth is suppressed at high densities due to competition (e.g. in the western Irish Sea), although recruitment dynamics or size-selective mortality may also shape the size structure of populations. Nephrops biomass available across FUs may be similar, reflecting a constant yield due to the inverse relationship between individual size and population density. Gaps in the understanding of Nephrops' ecology reflect uncertain ageing criteria, reliance on fisheries-dependent data and few if any undisturbed habitats in which to examine fisheries-independent interactions. PMID:23668587

Johnson, Mark P; Lordan, Colm; Power, Anne Marie

2013-01-01

146

Global patterns of fragmentation and connectivity of mammalian carnivore habitat  

PubMed Central

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

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

2011-01-01

147

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

PubMed Central

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

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

2012-01-01

148

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

2012-07-27

149

Restoration of Mangrove Habitat.  

National Technical Information Service (NTIS)

This technical note provides general guidelines for restoration of mangrove habitat. In the United States, mangroves naturally occur in Florida, Louisiana, and Texas. They also occur naturally in other areas that fall under Corps of Engineers jurisdiction...

R. Lewis B. Streever R. F. Theriot

2000-01-01

150

Adaptive morphological shifts to novel habitats in marine sculpin fishes.  

PubMed

Sculpin fishes of the North American Pacific Coast provide an ideal opportunity to examine whether adaptive morphological character shifts have facilitated occupation of novel habitat types because of their well-described phylogeny and ecology. In this group, the basal-rooted species primarily occupy the subtidal habitat, whereas the species in the most distal clades are found in the intertidal. We tested multiple evolutionary models to determine whether changes in body size and changes in number of scales are adaptive for habitat use in sculpins. Based on a statistically robust, highly resolved molecular phylogeny of 26 species of sculpins, in combination with morphometric and habitat affinity data, our analyses show that an adaptive model based on habitat use best explains changes in body size and number of scales. The habitat model was statistically supported over models of neutral evolution, stabilizing selection across all habitats, and three clade-based models. We suggest that loss of scales and reduction of body size in the intertidal may facilitate cutaneous breathing in air when tidepools become hypoxic during low tides. This study demonstrates how the combined use of phylogenetic, ecological and statistical approaches helps to identify traits that are likely adaptive to novel habitats. PMID:23316868

Knope, M L; Scales, J A

2013-01-14

151

Migratory Waterfowl Habitat Selection in Relation to Aquatic Vegetation.  

National Technical Information Service (NTIS)

This technical note describes studies of environmental conditions and habitat quality of replicated pond ecosystems dominated by populations of exotic plants or mixed communities of native aquatic plants. Study ponds were similar in depth, size, and shape...

G. O. Dick J. K. Smith R. M. Smart

2004-01-01

152

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.

153

Spectrum of Habitats  

NSDL National Science Digital Library

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

154

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

155

Habitat complexity reduces the growth of aggressive and dominant brown trout ( Salmo trutta ) relative to subordinates  

Microsoft Academic Search

Animals often prefer areas containing physical structure, and population density often increases with structural complexity, presumably because physical complexity in habitats may offer protection from predators and aggressive competitors. Consequently, increased habitat complexity often results in reduced territory size, lower aggression levels and reduced resource monopolisation by dominants. If behavioural plasticity is limited at early life stages, increased habitat complexity

Johan Höjesjö; Jörgen Johnsson; Torgny Bohlin

2004-01-01

156

Fish Habitat and Fish Populations in a Southern Appalachian Watershed before and after Hurricane Hugo  

Microsoft Academic Search

Habitat features and relative abundance of all fish species were estimated in 8.4 km of a small mountain stream system before and 11 months after Hurricane Hugo crossed the southern Appalachians in September 1989. There was no change in the total amount (area) of each habitat type but the total number of habitat units decreased and average size and depth

C. ANDREW DOLLOFF; PATRICIA A. FLEBBE; MICHAEL D. OWEN

1994-01-01

157

Habitat configuration affects colonisation of epifauna in a marine algal bed  

Microsoft Academic Search

Habitat fragmentation is a threat to the preservation of both terrestrial and marine biodiversity. While terrestrial systems have been well studied, relatively few studies have considered how changes to the spatial arrangement of habitats affect fauna in marine systems. In this study, sampling and manipulative experiments examined the effects of varying the size and isolation of habitat patches on the

David A. Roberts; Alistair G. B. Poore

2006-01-01

158

Habitat Suitability Index Models: Fallfish  

USGS Publications Warehouse

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

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

1983-01-01

159

Living Things and their Habitats  

NSDL National Science Digital Library

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

D., Mrs.

2006-10-11

160

Habitat Suitability Index Models: Osprey  

USGS Publications Warehouse

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 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.

Vana-Miller, Sandra L.

1987-01-01

161

Habitat Suitability Index Models: Bobcat  

USGS Publications Warehouse

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

Boyle, Katherine A.; Fendley, Timothy T.

1987-01-01

162

Habitat Suitability Index Models: Bullfrog  

USGS Publications Warehouse

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

Graves, Brent M.; Anderson, Stanley H.

1987-01-01

163

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

164

Habitat goes green  

SciTech Connect

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

Kriescher, P.; Smith, M.

1999-12-01

165

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

166

Chesapeake Bay Program: Habitats  

NSDL National Science Digital Library

This resource explains that all plants and animals that live in the Chesapeake Bay region have specific needs that must be met in order for them to live there, and also that an area has to have the right combination of food, light, temperature, water, nutrients, shelter and other necessities to be a good habitat. Students will discover that in the Chesapeake Bay region there are five major categories of habitat: forests, wetlands, streams and rivers, shallow water, aquatic reefs and open bay. There is background information and several subtopics for each category.

167

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

168

Habitat destruction, habitat restoration and eigenvector–eigenvalue relations  

Microsoft Academic Search

According to metapopulation theory, the capacity of a habitat patch network to support the persistence of a species is measured by the metapopulation capacity of the patch network. Mathematically, metapopulation capacity is given by the leading eigenvalue ?M of an appropriately constructed non-negative n×n matrix M, where n is the number of habitat patches. Both habitat destruction (in the sense

Otso Ovaskainen

2003-01-01

169

Earth is a Marine Habitat. Habitat Conservation Program.  

ERIC Educational Resources Information Center

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

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

170

Earth is a Marine Habitat. Habitat Conservation Program.  

ERIC Educational Resources Information Center

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

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

171

Movements and habitat use of mallard broods in northeastern California  

USGS Publications Warehouse

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

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

1994-01-01

172

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...

173

Habitats of the Pond  

NSDL National Science Digital Library

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

Science, Lawrence H.

1981-01-01

174

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

175

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.

O'Neil; Thomas (Corvallis, OR)

2010-03-23

176

Habitat Suitability Index Models: Bluegill  

USGS Publications Warehouse

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

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

1982-01-01

177

Habitat Suitability Models: Black Crappie.  

National Technical Information Service (NTIS)

Characteristics and habitat requirements of the black crappie (Pomoxis nigromaculatus) are described in a review of the literature. This information is then used as a basis for the development of Habitat Suitability Index models.

E. A. Edwards D. A. Krieger M. Bacteller

1982-01-01

178

Effects of an attractive sink leading into maladaptive habitat selection.  

PubMed

Habitat sinks can attract dispersing animals if high mortality or breeding failure are difficult to detect (e.g., when due to human hunting or pollution). Using a simple deterministic model, we explore the dynamics of such source-sink systems considering three scenarios: an avoided sink, no habitat preference, and an attractive sink. In the second two scenarios, there is a threshold proportion of sink habitat above which the whole population decreases to extinction, but this extinction threshold varies with habitat preference and the relative qualities of the two habitat types. Hence, it would be necessary to know the habitat preferences of any species in a source-sink system to interpret data on population increases and declines. In the attractive sink scenario, small changes in the proportion of sink habitat may have disproportionate effects on the population persistence. Also, small changes in growth rates at the source and the sink severely affect the threshold and the time of extinction. For some combinations of demographic parameters and proportion of habitat sink, the decline affects the source first; thus, during some time, it will be hidden to population monitoring at the sink, where numbers can even increase. The extinction threshold is also very sensitive to the initial population sizes relative to carrying capacity. Attractive sinks represent a novel aspect of source-sink dynamics with important conservation and management implications. PMID:18707324

Delibes, M; Gaona, P; Ferreras, P

2001-09-01

179

Linking habitat mosaics and connectivity in a coral reef seascape.  

PubMed

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

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

2012-09-04

180

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.

181

Habitat Suitability Index Models: Brewer's Sparrow  

USGS Publications Warehouse

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

Short, Henry L.

1984-01-01

182

Defining dynamic pelagic habitats in oceanic waters off eastern Australia  

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

183

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

184

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

185

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.

186

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.

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

2011-01-01

187

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

188

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

Microsoft Academic Search

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

Weidong Gu; Robert K. Swihart

2004-01-01

189

Habitat Selection by Apache Trout in Six East-Central Arizona Streams  

Microsoft Academic Search

Information on habitat selection by Apache trout Oncorhynchus gilae apache is needed to help recovery efforts for this federally threatened species. We investigated Apache trout habitat selection in six White Mountain streams in east-central Arizona. We measured environmental characteristics at used sites and randomly selected available sites and modeled habitat selection using forward step-wise logistic regression, for two size-classes of

Christopher J. Cantrell; Anthony T. Robinson; Lorraine D. Avenetti

2005-01-01

190

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.

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

2013-01-01

191

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

2013-06-20

192

Contrasting effects of habitat loss and fragmentation on coral-associated reef fishes.  

PubMed

Disturbance can result in the fragmentation and/or loss of suitable habitat, both of which can have important consequences for survival, species interactions, and resulting patterns of local diversity. However, effects of habitat loss and fragmentation are typically confounded during disturbance events, and previous attempts to determine their relative significance have proved ineffective. Here we experimentally manipulated live coral habitats to examine the potential independent and interactive effects of habitat loss and fragmentation on survival, abundance, and species richness of recruitment-stage, coral-associated reef fishes. Loss of 75% of live coral from experimental reefs resulted in low survival of a coral-associated damselfish and low abundance and richness of other recruits 16 weeks after habitat manipulations. In contrast, fragmentation had positive effects on damselfish survival and resulted in greater abundance and species richness of other recruits. We hypothesize that spacing of habitat through fragmentation weakens competition within and among species. Comparison of effect sizes over the course of the study period revealed that, in the first six weeks following habitat manipulations, the positive effects of fragmentation were at least four times stronger than the effects of habitat loss. This initial positive effect of fragmentation attenuated considerably after 16 weeks, whereas the negative effects of habitat loss increased in strength over time. There was little indication that the amount of habitat influenced the magnitude of the habitat fragmentation effect. Numerous studies have reported dramatic declines in coral reef fish abundance and diversity in response to disturbances that cause the loss and fragmentation of coral habitats. Our results suggest that these declines occur as a result of habitat loss, not habitat fragmentation. Positive fragmentation effects may actually buffer against the negative effects of habitat loss and contribute to the resistance of reef fish populations to declines in coral cover. PMID:21870624

Bonin, Mary C; Almany, Glenn R; Jones, Geoffrey P

2011-07-01

193

Habitat use and spatial segregation of adult spottail sharks Carcharhinus sorrah in tropical nearshore waters.  

PubMed

An array of acoustic receivers deployed in Cleveland Bay, north Queensland, Australia, passively tracked 20 adult spottail sharks Carcharhinus sorrah over 2 years (2009-2010) to define patterns in movement and habitat use. Individuals were present in the study site for long periods, ranging from 8 to 408 days (mean = 185). Size and location of home ranges did not vary over time. A high level of segregation occurred among C. sorrah, with individuals using different types of habitat and showing strong attachment to specific regions. The depth of habitat individuals used varied between sexes. Males tended to use a narrow range of habitat depths within the study site (2·8-6·0 m), whereas females used shallower habitats (1·4-6·2 m) and displayed a seasonal shift in the depth of habitat used. Mean monthly habitat depth used varied by as much as 2 m for females, with individuals using shallower habitats during the winter months. Long-term presence and consistent home ranges suggest that Cleveland Bay provides important habitat for C. sorrah. By defining patterns in the use of nearshore habitats for C. sorrah, this study improves the understanding of the movement and habitat use of smaller-bodied coastal sharks and may help provide guidance for the management of their populations. PMID:22471798

Knip, D M; Heupel, M R; Simpfendorfer, C A

2012-03-02

194

Clay Animals and Their Habitats  

ERIC Educational Resources Information Center

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

Adamson, Kay

2010-01-01

195

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

196

Effects of pond size and consequent predator density on two species of tadpoles  

Microsoft Academic Search

Experimental ponds were used as a model system of habitat patches to study the effect of habitat size on the relative growth performance of tadpoles of Bufo americanus and Pseudacris triseriata, and on colonization by predatory insects. Three pond depths and surface areas were habitat size treatments in a replicated, factorial experiment. Tadpoles of both species were astablished together at

Peter B. Pearman

1995-01-01

197

Habitat Suitability Index Models: Wood Duck.  

National Technical Information Service (NTIS)

A review and synthesis of existing information were used to develop models for breeding and wintering habitats for the wood duck (Aix sponsa). The models are scaled to produce indices of habitat suitability between 0 (unsuitable habitat) and 1 (optimally ...

P. J. Sousa A. H. Farmer

1983-01-01

198

RESEARCH ON FISH AND WILDLIFE HABITAT  

EPA Science Inventory

This publication contains a series of monographs that discuss and describe computerized habitat management tools and data bases; habitat classification systems; the impact of public policy on habitats and ecosystems; the ecological values of wetlands; progress on research in ecot...

199

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

200

Modelling effects of habitat fragmentation on the ability of trees to respond to climatic warming  

Microsoft Academic Search

The ability of trees to migrate in response to climatic warming was simulated under various conditions of habitat availability. The model uses Holocene tree migration rates to approximate maximum migration rates in a forested landscape. Habitat availability and local population size was varied systematically under two dispersal and colonization models. These dispersal models varied in the likelihood of long-distance dispersal

Mark W. Schwartz

1993-01-01

201

Woodland key habitats evaluated as part of a functional reserve network  

Microsoft Academic Search

Woodland key habitats (WKHs) represent a potentially cost-efficient means to protect biodiversity in managed forests. The Forest Act of Finland defines 13 habitat types of WKHs, which enjoy legal protection. It has been argued that WKHs are too small-sized and scattered in occurrence to be actually important in the maintenance of forest biodiversity. However, from the species’ perspective, WKHs form

Anne Laita; Mikko Mönkkönen; Janne S. Kotiaho

2010-01-01

202

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

Microsoft Academic Search

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

M. M. Gowing

2003-01-01

203

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

204

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

205

Habitat suitability for three species of Anopheles mosquitoes: larval growth and survival in reciprocal placement experiments.  

PubMed

Larval habitats of the main malaria vectors in Belize are associated with three distinctly different aquatic environments: marshes with sparse macrophytes and cyanobacterial mats (Anopheles albimanus), tall dense macrophyte marshes (An. vestitipennis), and floating detritus assemblages within freshwater rivers (An. darlingi). We assessed species-specific habitat suitability based upon nutrient characteristics using larval survival rates (SR) and wing lengths (WL) from floating habitat enclosures. Anopheles albimanus showed a high SR (81%) in all three habitats, while An. vestitipennis had a similarly high SR in its own habitat (82%) and An. darlingi's habitat (81%). Anopheles darlingi only showed high SR (85%) in its own habitat. Both An. vestitipennis and An. darlingi showed very low SR in the An. albimanus habitat. There were no significant WL differences among field-caught, laboratory-reared, and experimental populations of An. vestitipennis and An. albimanus, with the exception of An. vestitipennis experimental populations and An. vestitipennis field populations placed in the An. albimanus habitat. Habitat quality indicators, particulate organic carbon (POC), dissolved organic carbon (DOC), and particulate organic nitrogen (PON), were consistently higher in An. vestitipennis habitats than in the habitats of the other two species. Correspondingly, An. vestitipennis adults were larger when measured both as dry mass and from WL. There were no differences in dry mass, lipids, or protein content among the same species reared at different locations. We compared SR and WL among mosquitoes from shaded and unshaded containers to test whether the high mortality rates for An. vestitipennis and An. darlingi in the An. albimanus habitat were due to intense sun exposure. There were no significant differences among developmental times, survivorship, or adult size for shaded versus sun-exposed populations. This indicates that other factors such as larval toxins, predator avoidance, interspecific species competition, etc. may be responsible for the higher mortality rates in those species not adapted to this particular habitat. PMID:18260505

Grieco, John P; Rejmánková, Eliska; Achee, Nicole L; Klein, Corinne N; Andre, Richard; Roberts, Donald

2007-12-01

206

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.

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

2011-01-01

207

Habitats and taphonomy of Europa  

NASA Astrophysics Data System (ADS)

Jupiter's moon Europa possesses an icy shell kilometers thick that may overlie a briny ocean. The inferred presence of water, tidal and volcanic energy, and nutrients suggests that Europa is potentially inhabited by some kind of life; indeed Europa is a primary target in the search for life in the Solar System although no evidence yet exists for any kind of life. The thickness of the icy crust would impose limits on life, but at least 15 broad kinds of habitats seem possible for Europa. They include several on the sea floor, at least 3 in the water column, and many in the ice itself. All of these habitats are in, or could be transported to, the icy shell where they could be exposed by geologic activity or impacts so they might be explored from the surface or orbit by future planetary missions. Taphonomic processes that transport, preserve, and expose habitats include buoyant ice removing bottom habitats and sediment to the underside of the ice, water currents depositing components of water column habitats on the ice bottom, cryovolcanoes depositing water on the surface, tidal pumping bringing water column and ice habitats to the near-surface ice, and subice freezing and diapiric action incorporating water column and bottom ice habitats into the lower parts of the icy shell. The preserved habitats could be exposed at or near the surface of Europa chiefly in newly-formed ice, tilted or rotated ice blocks, ridge debris, surface deposits, fault scarps, the sides of domes and pits, and impact craters and ejecta. Future exploration of Europa for life must consider careful targeting of sites where habitats are most likely preserved or exist close to the surface.

Lipps, Jere H.; Rieboldt, Sarah

2005-10-01

208

HabitatSpace: Multidimensional Characterization of Pelagic Essential Fish Habitat.  

National Technical Information Service (NTIS)

Habitat is recognized as crucial to the survival and recovery of exploited species. Climate change, environmental variability, and increased anthropogenic modification of the oceans add a sense of urgency to the correct identification, monitoring and cons...

C. J. Beegle-Krauss D. Steube S. M. Mesick T. C. Vance

2010-01-01

209

Management of interactions between endangered species using habitat restoration  

Microsoft Academic Search

Commonly used conservation strategies may be insufficient when deleterious interactions between co-habiting endemic species occur. The decline in the population size of the endangered Leon Springs pupfish, Cyprinodon bovinus, in Diamond Y Spring, Texas has been partially attributed to egg-predation by the endangered Pecos gambusia, Gambusia nobilis. This interaction is related to changes in habitat availability; therefore, we aim to

J. M. Gumm; J. L. Snekser; J. M. Leese; K. P. Little; J. K. Leiser; V. E. Imhoff; B. Westrick; M. Itzkowitz

2011-01-01

210

Creating an energy efficient habitat  

SciTech Connect

Habitat for Humanity is working to provide housing that is priced within reach of low-income buyers, is safe and durable, and has reasonable energy and maintenance costs. But it takes care and patience to ensure that these and other considerations do not slip through the cracks. Topics covered in this article include the following: house plans maximize performance per dollar; new construction or rehab?; new approaches including water and sewer costs, tight/not too tight; affordable vs. efficient; a role for the residential energy profession; Habitat`s environmental initiative. 2 tabs.

Wigington, L.

1997-07-01

211

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

212

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

PubMed

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

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

2008-12-01

213

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

SciTech Connect

Brine spills associated with petroleum extraction can reduce the amount of suitable habitat and increase habitat fragmentation for many terrestrial animals. We conducted a simulation study to quantify the effects of habitat loss and fragmentation on a solitary mammal predator. To provide focus, we adopted biological attributes of the American badger (Taxidea taxus) and environmental attributes of the Tallgrass Prairie Preserve in Oklahoma. We simulated badger activities on landscapes with different degrees of habitat loss and fragmentation using a spatially explicit and individual-based population model. Both habitat loss and fragmentation increased the incidence of habitat-related mortality and decreased the proportion of eligible females that mated, which decreased final population sizes and the likelihood of persistence. Parameter exploration suggested that steep, threshold-like, responses to habitat loss occurred when animals included high-risk habitat in their territories. Badger populations showed a steeper decline with increasing habitat loss on landscapes fragmented by spills than on less fragmented landscapes. Habitat fragmentation made it difficult for badgers to form high-quality territories, and exposed individuals to higher risk while seeking to establish a territory. Our simulations also suggest that an inability to find mates (an Allee effect) becomes increasingly important for landscapes that support a sparse distribution of territories. Thus, the presence of unmated females with territories may foreshadow population decline in solitary species that do not normally tolerate marginal adults.

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

2005-01-01

214

Handbook for Habitat Evaluation Procedures.  

National Technical Information Service (NTIS)

The development and implementation of a habitat evaluation system for measuring effects of water development projects on fish, wildlife, and related resources has been given the highest priority by the National Coordinating Committee for fish and wildlife...

B. S. Flood M. E. Sangster R. D. Sparrowe T. S. Baskett

1977-01-01

215

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

216

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

217

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

USGS Publications Warehouse

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

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

1997-01-01

218

Models that predict standing crop of stream fish from habitat variables  

Treesearch

Frequent problems were too small a sample size, possible bias caused by ... assumptions about capture probabilities when estimating standing crop. ... We found five main ways stream-fish-habitat models are used in fishery management .

219

Habitat Suitability Index Models: Mottled Duck.  

National Technical Information Service (NTIS)

A review and synthesis of existing information were used to develop a habitat model for mottled duck (Anas fulvigula). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1 (Optimally suitable habitat) for coa...

J. C. Rorabaugh P. J. Zwank

1983-01-01

220

Hedgerows as habitat for woodland plants  

Microsoft Academic Search

For hedgerows to act as corridors for woodland plants they must provide habitat conditions to suit species’ autecological requirements. This supposition was tested by examining differences in the habitat and autecological characteristics of woodland plants according to their relative frequency in hedgerows and woodlands using a novel Habitat Preference Index (HPI). Indicator values for habitat and autecological characteristics of plant

D. McCollin; J. I. Jackson; R. G. H. Bunce; C. J. Barr; R. Stuart

2000-01-01

221

Habitat Suitability Index Models: White Ibis.  

National Technical Information Service (NTIS)

A review and synthesis of existing information were used to develop a model for evaluating White Ibis habitat quality. The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimal habitat) for Southern Atl...

T. M. Hingtgen R. Mulholland R. W. Repenning

1985-01-01

222

Habitat Suitability Index Models: Laughing Gull.  

National Technical Information Service (NTIS)

A review and synthesis of existing information were used to develop a habitat model for laughing gull (Larus atricilla). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimally suitable habitat) for...

A. V. Zale R. Mulholland

1985-01-01

223

Habitat Suitability Index Models: Black Brant  

USGS Publications Warehouse

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

Schroeder, Richard L.

1984-01-01

224

Habitat Suitability Index Models: Bigmouth Buffalo  

USGS Publications Warehouse

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

Edwards, Elizabeth A.

1983-01-01

225

Habitat Suitability Index Models: Common Shiner  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for common shiner (Notropis cornutus). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for the northeastern range of the common shiner in North America. Habitat suitability indexes (HSI's) are designed for use with the habitat evaluation procedures developed by the U.S. Fish and Wildlife Service. Also included are discussions of Suitability Index (SI) curves as used in the Instream Flow Incremental Methodology (IFIM) and SI curves available for an IFIM analysis of smallmouth bass habitat.

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

1983-01-01

226

Habitat Suitability Index Models: Eastern Brown Pelican  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a habitat model for the eastern brown pelican (Pelecanus occidentalis carolinensis). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimal habitat) for coastal areas within the eastern brown pelican's breeding range. Habitat suitability indices are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for application of the eastern brown pelican habitat model and techniques for measuring model variables are described.

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

1985-01-01

227

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.

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

2011-01-01

228

Distribution and habitat partitioning of immature bull sharks ( Carcharhinus leucas ) in a Southwest Florida estuary  

Microsoft Academic Search

The distribution and salinity preference of immature bull sharks (Carcharhinus leucas) were examined based on the results of longline surveys in three adjacent estuarine habitats in southwest Florida: the Caloosahatchee\\u000a River, San Carlos Bay, and Pine Island Sound. Mean sizes were significantly different between each of these areas indicating\\u000a the occurrence of size-based habitat partitioning. Neonate and young-of-the-year animals occurred

Colin A. Simpfendorfer; Garin G. Freitas; Tonya R. Wiley; Michelle R. Heupel

2005-01-01

229

What drives variation in habitat use by Anolis lizards: habitat availability or selectivity?  

Microsoft Academic Search

Geographic variation in habitat availability may drive geographic variation in a species' habitat use; alterna- tively, species adapted to particular habitat characteristics may use a habitat regardless of its availability within an environ- ment. In this study, we investigated habitat use of two sympatric species of Anolis lizards that are morphologically specialized to use different microhabitats. We examined variation in

M. A. Johnson; R. Kirby; S. Wang; J. B. Losos

2006-01-01

230

Habitat Suitability Index Models: Smallmouth Buffalo  

USGS Publications Warehouse

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

Edwards, Elizabeth A.; Twomey, Katie

1982-01-01

231

Habitat Suitability Index Models: Barred Owl  

USGS Publications Warehouse

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

Allen, Arthur W.

1987-01-01

232

Habitat Suitability Index Models: Spotted Owl  

USGS Publications Warehouse

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

Laymon, Stephen A.; Salwasser, Hal; Barrett, Reginald H.

1985-01-01

233

Habitat Suitability Index Models: Belted Kingfisher  

USGS Publications Warehouse

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

Prose, Bart L.

1985-01-01

234

Habitat Suitability Index Models: American Woodcock (Wintering)  

USGS Publications Warehouse

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

Cade, Brian S.

1985-01-01

235

Habitat Suitability Index Models: Black Bullhead  

USGS Publications Warehouse

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

Stuber, Robert J.

1982-01-01

236

Habitat Suitability Index Models: Flathead Catfish  

USGS Publications Warehouse

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

Lee, Lawrence A.; Terrell, James W.

1987-01-01

237

Habitat Suitability Index Models: Common Carp  

USGS Publications Warehouse

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

Edwards, Elizabeth A.; Twomey, Katie

1982-01-01

238

Habitat Suitability Index Models: Blue Grouse  

USGS Publications Warehouse

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

Schroeder, Richard L.

1984-01-01

239

Habitat Suitability Index Models: Greater Sandhill Crane  

USGS Publications Warehouse

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

Armbruster, Michael J.

1987-01-01

240

Habitat Suitability Index Models: Brown Thrasher  

USGS Publications Warehouse

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

Cade, Brian S.

1986-01-01

241

Habitat Suitability Index Models: Green Sunfish  

USGS Publications Warehouse

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

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

1982-01-01

242

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

243

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.

Juliano, Steven A.

2009-01-01

244

Habitat use among size groups of monomorphic whitefish Coregonus lavaretus  

Microsoft Academic Search

The whitefish (Coregonus lavaretus) in Lake Tyrifjorden, southeastern Norway, is monomorphic with regard to gill raker number: (x=32), and exhibits a bimodal length distribution. The small whitefish (27 cm) were mainly distributed in the upper layers of the pelagic zone. Both small and large whitefish fed on zooplankton in the pelagic zone. In the littoral zone the diet of the

Dag O. Hessen; Jostein Skurdal; Leif Asbjørn Vøllestad; Dag Berge

1986-01-01

245

High quantitative and no molecular differentiation of a freshwater snail (Galba truncatula) between temporary and permanent water habitats.  

PubMed

We investigate the variation in quantitative and molecular traits in the freshwater snail Galba truncatula, from permanent and temporary water habitats. Using a common garden experiment, we measured 20 quantitative traits and molecular variation using seven microsatellites in 17 populations belonging to these two habitats. We estimated trait means in each habitat. We also estimated the distributions of overall genetic quantitative variation (QST), and of molecular variation (FST), within and between habitats. Overall, we observed a lack of association between molecular and quantitative variance. Among habitats, we found QST>FST, an indication of selection for different optima. Individuals from temporary water habitat matured older, at a larger size and were less fecund than individuals from permanent water habitat. We discuss these findings in the light of several theories for life-history traits evolution. PMID:17688547

Chapuis, Elodie; Trouve, Sandrine; Facon, Benoit; Degen, Loïc; Goudet, Jerome

2007-08-01

246

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

2008-01-10

247

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

248

Habitat Suitability Index Models: Black Crappie  

USGS Publications Warehouse

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

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

1982-01-01

249

Umatilla Basin Habitat Improvement Project.  

SciTech Connect

This annual report is in fulfillment of contract obligations with Bonneville Power Administration which is the funding source for the Oregon Department of Fish and Wildlife's Umatilla Basin Habitat Improvement Project. The major activities undertaken during this report period were: procurement of 17 cooperative lease agreements with private landowners, design and layout of 8.6 miles of riparian exclosure fence and 3.0 miles of instream structures, development of five fencing contracts and six instream work contracts. Results include implementation of 10 miles of fencing and 3 miles of instream work. Other activities undertaken during this report period are: data collection from 90 habitat monitoring transects, collection and summarization of temperature data, photopoint establishment, coordination with numerous agencies and tribes and education of all age groups on habitat improvement and protection. 4 refs., 4 figs., 6 tabs.

Bailey, Timothy D.

1990-01-01

250

Commercial post larval collector habitat  

US Patent & Trademark Office Database

The collector habitat device comprises panels of non-biodegradable and/or synthetic fibrous material set in durable weatherproof frames and attached to a base; when placed in, the panels hang within the water column providing numerous parallel settlement surfaces for post-larvae. A float assembly, optionally attached to the opposite side of the base from the panels, allows the device to float just below the water's surface. The collector habitat device also incorporates a guard, surrounding the panels, with apertures to allow settlement-stage post-larvae access to the settlement surfaces, while preventing larger organisms and potential predators from gaining access. The collector habitat device also, optionally, incorporates an optionally removable/re-attachable reservoir hung below the guard; and an optional olfactory attractant delivery device.

Power; Robert M. (Norwich, GB)

2011-01-04

251

Habitat type and density influence vocal signal design in satin bowerbirds.  

PubMed

1. This study provided a thorough test of the acoustic adaptation hypothesis using a within-species comparison of call structure involving a wide range of habitat types, an objective measure of habitat density and direct measures of habitat-related attenuation. 2. The structure of the bower advertisement call of the satin bowerbird was measured in 16 populations from throughout the species' range and related to the habitat type and density at each site. Transmission of white noise, pure tones and different bowerbird dialects was measured in five of six habitat types inhabited by satin bowerbirds. 3. Bowerbird advertisement call structure converged in similar habitats but diverged among different habitats; this pattern was apparent at both continent-wide and local geographical scales. Bowerbirds' call structures differed with changes in habitat density, consistent with the acoustic adaptation hypothesis. Lower frequencies and less frequency modulation were utilized in denser habitats such as rainforest and higher frequencies and more frequency modulation were used in the more open eucalypt-dominated habitats. 4. The white noise and pure tone transmission measurements indicated that different habitats varied in their sound transmission properties in a manner consistent with the observed variation in satin bowerbird vocalizations. 5. There was no effect of geographical proximity of recording locations, nor was there the predicted inverse relationship between frequency and body size. 6. These findings indicate that the transmission qualities of different habitats have had a major influence on variation in vocal phenotypes in this species. In addition, previously published molecular data for this species suggest that there is no effect of genetic relatedness on call similarity among satin bowerbird populations. PMID:16638007

Nicholls, James A; Goldizen, Anne W

2006-03-01

252

Effects of individual condition and habitat quality on natal dispersal behaviour in a small rodent.  

PubMed

1. Individuals should benefit from settling in high-quality habitats, but dispersers born under favourable conditions have a better physical condition and should therefore be more successful at settling in high-quality habitats. 2. We tested these predictions with root voles (Microtus oeconomus) by a manipulation of individual condition through litter-size enlargement and reduction during lactation combined with a manipulation of habitat quality through degradation of the vegetation cover. We accurately monitored movements of 149 juveniles during a settlement and breeding period of 3 months. 3. The litter size treatment had long-lasting effects on body size, life-history traits and home range size, but did not influence dispersal behaviour. 4. Different stages of dispersal were influenced by habitat quality. In low-quality patches, females dispersed earlier, spent more time prospecting their environment before settling, and settlers had a smaller adult body size than in high-quality patches. Preference and competition for high-quality patches is likely adaptive as it increased fitness both in terms of survival and reproduction. 5. We found no interactive effect of individual condition and habitat quality on natal dispersal and habitat selection. 6. These findings suggest that immediate conditions are more important determinants of dispersal decisions than conditions experienced early in life. PMID:21521215

Rémy, Alice; Le Galliard, Jean-François; Gundersen, Gry; Steen, Harald; Andreassen, Harry P

2011-04-27

253

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

254

Habitat Suitability Index Models: Laughing Gull  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a habitat model for laughing gull (Larus atricilla). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimally suitable habitat) for areas along the Gulf of Mexico coast. Habitat suitability indices are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for application of the model and techniques for measuring model variables are described.

Zale, Alexander V.; Mulholland, Rosemarie

1985-01-01

255

Indirect effects of species interactions on habitat provisioning.  

PubMed

Species that shelter in a biogenic habitat can influence their refugia and, in turn, play an essential role in shaping local patterns of biodiversity. Here we explore a positive feedback loop between the provisioning rate of habitat-forming branching corals and their associated fishes and show how interactions between two groups of fish--the planktivorous damselfish and predatory hawkfish--altered the feedback. A field experiment confirmed that skeletal growth of branching coral (genus Pocillopora) increased substantially with increasing numbers (biomass) of resident fishes, likely because they greatly increased the interstitial concentrations of nutrients. Because there is a positive relationship between colony size and number (biomass) of associated fishes (primarily damselfishes in the Family Pomacentridae), a structure-function feedback loop exists in which increasing numbers of damselfish enhance coral growth and larger corals host greater abundances (and species richness) of fish. However, interactions between damselfishes and arc-eye hawkfish, Paracirrhites arcatus, a largely solitary resident, can disrupt this positive feedback loop. Field surveys revealed a marked pattern of fish occupancy related to coral size: Pocillopora colonies of sufficient size to host fish (>40 cm circumference) had either groups of damselfish or an arc-eye hawkfish; only larger colonies (>75 cm) were occupied by both the damselfish and hawkfish. Subsequent short- and long-term experiments revealed that on intermediate-sized Pocillopora colonies, arc-eye hawkfish prevented the establishment of damselfish by suppressing their recruitment. The demographic consequences to the host coral were substantial; in a 1-year-long experiment, intermediate-size Pocillopora occupied by hawkfish grew at half the rate of corals that hosted groups of damselfish. These findings indicate that: (1) species which occupy a biogenic habitat can enhance the provisioning rate of their habitat; (2) such positive feedbacks between community structure and ecosystem function can be disrupted by a strong interactor; (3) even substantial consequences on ecosystem processes that arise can be difficult to discern. PMID:21274572

Holbrook, Sally J; Schmitt, Russell J; Brooks, Andrew J

2011-01-28

256

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

2006-06-09

257

Local extinction of dragonfly and damselfly populations in low- and high-quality habitat patches.  

PubMed

Understanding the risk of extinction of a single population is an important problem in both theoretical and applied ecology. Local extinction risk depends on several factors, including population size, demographic or environmental stochasticity, natural catastrophe, or the loss of genetic diversity. The probability of local extinction may also be higher in low-quality sink habitats than in high-quality source habitats. We tested this hypothesis by comparing local extinction rates of 15 species of Odonata (dragonflies and damselflies) between 1930-1975 and 1995-2003 in central Finland. Local extinction rates were higher in low-quality than in high-quality habitats. Nevertheless, for the three most common species there were no differences in extinction rates between low- and high-quality habitats. Our results suggest that a good understanding of habitat quality is crucial for the conservation of species in heterogeneous landscapes. PMID:20412087

Suhonen, Jukka; Hilli-Lukkarinen, Milla; Korkeamäki, Esa; Kuitunen, Markku; Kullas, Johanna; Penttinen, Jouni; Salmela, Jukka

2010-04-20

258

Umatilla Basin Habitat Improvement Project  

Microsoft Academic Search

This annual report is in fulfillment of contract obligations with Bonneville Power Administration which is the funding source for the Oregon Department of Fish and Wildlife's Umatilla Basin Habitat Improvement Project. The major activities undertaken during this report period were: procurement of 17 cooperative lease agreements with private landowners, design and layout of 8.6 miles of riparian exclosure fence and

Bailey; Timothy D

1990-01-01

259

MAINE ATLANTIC SALMON HABITAT - GENERAL  

EPA Science Inventory

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

260

Microbial Habitat on Kilimanjaro's Glaciers  

NASA Astrophysics Data System (ADS)

Kilimanjaro glaciers captured a history of microbial diversity and abundance of supraglacial habitats. We show that a majority of bacterial clones, as determined by bacterial 16S rRNA gene sequencing, are most closely related to those isolated from cold-water environments.

Ponce, A.; Beaty, S. M.; Lee, C.; Lee, C.; Noell, A. C.; Stam, C. N.; Connon, S. A.

2011-03-01

261

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

262

Enchanted Learning: Biomes-Habitats  

NSDL National Science Digital Library

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

263

Habitat Suitability Index Models: Gray Squirrel.  

National Technical Information Service (NTIS)

Habitat preferences and species characteristics of the gray squirrel (Sciurus carolinensis) are described in this publication. It is one of a series of Habitat Suitability Index (HSI) models and was developed through an analysis of available scientific da...

A. W. Allen

1982-01-01

264

Habitat Suitability Index Models: Gray Squirrel (Revised).  

National Technical Information Service (NTIS)

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, an...

A. W. Allen

1987-01-01

265

Hampton-Seabrook Estuary Habitat Restoration Compendium.  

National Technical Information Service (NTIS)

The Hampton-Seabrook Estuary Habitat Restoration Compendium (HSEHRC) is a compilation of information on the historic and current distributions of salt marsh and sand dune habitats and diadromous fishes within the Hampton-Seabrook Estuary watershed. These ...

A. L. Eberhardt D. M. Burdick

2009-01-01

266

Integration Process for the Habitat Demonstration Unit.  

National Technical Information Service (NTIS)

The Habitat Demonstration Unit (HDU) is an experimental exploration habitat technology and architecture test platform designed for analog demonstration activities The HDU project has required a team to integrate a variety of contributions from NASA center...

A. S. Howe J. Merbitz K. Kennedy T. Gill T. Tri

2010-01-01

267

Habitat Suitability Index Models: Bigmouth Buffalo.  

National Technical Information Service (NTIS)

A review and synthesis of existing information was used to develop riverine and lacustrine habitat models for Bigmouth buffalo (Ictiobus cyprinellus) a freshwater species. The models are scaled to produce indices of habitat suitability between 0 (unsuitab...

E. A. Edwards

1983-01-01

268

Habitat Suitability Index Models: Greater Sandhill Crane,  

National Technical Information Service (NTIS)

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the greater sandhill crane (Grus canadensis tabida). The model consolidates habitat use information into a framework appropriate for field appl...

M. J. Armbruster

1987-01-01

269

Habitat Suitability Index Models: Eastern Wild Turkey.  

National Technical Information Service (NTIS)

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...

R. L. Schroeder

1985-01-01

270

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...

271

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

Microsoft Academic Search

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

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

2005-01-01

272

Stoichiometry in an ecological context: testing for links between Daphnia P-content, growth rate and habitat preference  

Microsoft Academic Search

We used laboratory experiments with ten Daphnia taxa to test for links between Daphnia P-content, growth rate and habitat preference. The taxa represent a wide range of body sizes and most show distinct preferences for one of three habitats: shallow lakes, deep, stratified lakes or fishless ponds. Previous studies show that taxa from shallow lakes and fishless ponds experience high

William R. DeMott; Bryn J. Pape

2005-01-01

273

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

274

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

275

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

USGS Publications Warehouse

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

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

2003-01-01

276

JUVENILE BAY SCALLOP (ARGOPECTEN IRRADIANS) HABITAT PREFERENCES  

EPA Science Inventory

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

277

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

278

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

279

Habitat Use by Bats in Fragmented Forests  

Microsoft Academic Search

ABSTRACT Habitat disturbance associated with forest harvesting has various effects on wildlife. To assess the impact on bats, I used ultrasonic detectors to monitor relative habitat use by bats ,in disturbed ,forested sites and riparian areas. In addition, I experimentally tested the effect of spatial clutter on the foraging activity of bats. My results suggest that habitat use by foraging

D. Grindal

280

Habitats: Making Homes for Animals and Plants.  

ERIC Educational Resources Information Center

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

Hickman, Pamela M.

281

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

282

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

283

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

284

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

285

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

USGS Publications Warehouse

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

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

2004-01-01

286

Stream Crayfish Distribution Patterns and Habitat Associations in northern Mississippi  

NASA Astrophysics Data System (ADS)

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

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

2005-05-01

287

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.

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

2008-01-01

288

Importance of early successional habitat to ruffed grouse and American woodcock  

USGS Publications Warehouse

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

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

2001-01-01

289

Strategic Habitat Conservation Handbook: A Guide to Implementing the Technical Elements of Strategic Habitat Conservation (Version 1.0).  

National Technical Information Service (NTIS)

This guide describes the framework for strategic habitat conservation (SHC) enabling the efficient conservation of wildlife populations through habitat management, which is defined as protection of existing habitat, and habitat restoration or manipulation...

2008-01-01

290

Literature Summary and Habitat Suitability Index Model: Components of Summer Habitat for the Indiana Bat, 'Myotis sodalis'.  

National Technical Information Service (NTIS)

Contents: Literature Summary (Introduction, Natural History, Habitat Suitability Model, Maternity Roost Habitat, Foraging Habitat, Literature Cited); Indiana Bat (Myotis Sodalis) Summer Habitat Suitability Index Model (Introduction, Model structure, Forag...

K. Tyrell R. C. Romme V. Brack

1995-01-01

291

Habitat suitability index models: American eider (breeding)  

SciTech Connect

A review and synthesis of existing information was used to develop a model for evaluating the potential suitability of habitat along the coast of Maine for breeding American eider (Somateria mollissima dresseri). The model is scaled to produce an index from 0 (unsuitable habitat) to 1.0 (optimal habitat). Habitat suitability index models are designed for use with the Habitat Evaluation Procedures previously developed by the US Fish and Wildlife Service. Guidelines for model application are provided. 51 refs., 3 figs., 5 tabs.

Blumton, A.K.; Owen, R.B. Jr.; Krohn, W.B.

1988-02-01

292

Winter habitat–space use in a large arctic herbivore facing contrasting forage abundance  

Microsoft Academic Search

We analysed how changes in resource levels influence foraging trade-offs in late winter by wild Svalbard reindeer. Forage\\u000a plants, and particularly lichens, were less abundant at the overgrazed Brøggerhalvøya compared with the neighbouring Sarsøyra.\\u000a Strong interactions occurred between habitat selection, home range size, and feeding crater selection. At Brøggerhalvøya,\\u000a radiocollared females generally selected productive habitat (high summer NDVI; Normalised Difference

Brage Bremset Hansen; Ronny Aanes; Ivar Herfindal; Bernt-Erik Sæther; Snorre Henriksen

2009-01-01

293

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

294

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

295

Sexual segregation of seasonal foraging habitats in a non-migratory marine mammal  

Microsoft Academic Search

Many animal species segregate by sex. Such segregation may be social in nature, or ecological, or both. Grey seals (Halichoerus grypus), like many large mammals, are sexually size dimorphic. In size dimorphic species, allometric differences in morphology, metabolic rate and reproductive costs are likely. Such differences may require the sexes to use different foraging strategies or different habitats. To investigate

Greg A. Breed; W. D. Bowen; J. I. McMillan; M. L. Leonard

2006-01-01

296

The role of habitat area and edge in fragmented landscapes: definitively distinct or inevitably intertwined?  

Microsoft Academic Search

Over the past few decades, much research has focussed on the effects of habitat area (i.e., patch size) and edges in fragmented landscapes. We review and synthesize the literature on area and edge effects to identify whether the eco- logical processes influenced by patch size and edge are distinct, to summarize evidence for the relative effect of each, and to

Leslie Ries; James Battin; Anna D. Chalfoun

2007-01-01

297

Carnivorous Plants and Their Habitats  

NSDL National Science Digital Library

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

Nerz, Joachim

2002-06-18

298

Potential intertidal habitat restoration sites in the Duwamish River estuary  

SciTech Connect

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

Tanner, C.D.

1991-12-01

299

Do habitat shifts drive diversification in teleost fishes? An example from the pufferfishes (Tetraodontidae).  

PubMed

Habitat shifts are implicated as the cause of many vertebrate radiations, yet relatively few empirical studies quantify patterns of diversification following colonization of new habitats in fishes. The pufferfishes (family Tetraodon-tidae) occur in several habitats, including coral reefs and freshwater, which are thought to provide ecological opportunity for adaptive radiation, and thus provide a unique system for testing the hypothesis that shifts to new habitats alter diversification rates. To test this hypothesis, we sequenced eight genes for 96 species of pufferfishes and closely related porcupine fishes, and added 19 species from sequences available in GenBank. We time-calibrated the molecular phylogeny using three fossils, and performed several comparative analyses to test whether colonization of novel habitats led to shifts in the rate of speciation and body size evolution, central predictions of clades experiencing ecological adaptive radiation. Colonization of freshwater is associated with lower rates of cladogenesis in pufferfishes, although these lineages also exhibit accelerated rates of body size evolution. Increased rates of cladogenesis are associated with transitions to coral reefs, but reef lineages surprisingly exhibit significantly lower rates of body size evolution. These results suggest that ecological opportunity afforded by novel habitats may be limited for pufferfishes due to competition with other species, constraints relating to pufferfish life history and trophic ecology, and other factors. PMID:23496826

Santini, F; Nguyen, M T T; Sorenson, L; Waltzek, T B; Lynch Alfaro, J W; Eastman, J M; Alfaro, M E

2013-03-15

300

Macroinvertebrate Communities and Benthic Organic Matter in Sand Habitats of 15 Northern Michigan Streams  

NASA Astrophysics Data System (ADS)

Relationships between benthic organic matter (BOM) and macroinvertebrates have been well studied in streams with coarse substrates, but such relationships have been little studied in sand habitats, despite the abundance of sand in many streams. These relationships were investigated in sand habitats of 15 streams in three watersheds of the Ottawa National Forest, Michigan. Sand habitats in the 15 streams varied widely in mean total BOM quantity (112 to 1814 g AFDM·m-2) and size composition [very fine BOM (VFBOM, 0.45-250 ?m), 0-58%; fine BOM (FBOM, 250 ?m-1 mm), 11-27%; coarse BOM (CBOM, >1 mm), 27-81%] but differences were still detected among watersheds (VFBOM, ANOVA, F2,11 = 8.69, p = 0.005; CBOM, F2,11 = 11.15, p = 0.002). Sand-dwelling invertebrates were dominated by gathering-collectors, primarily Chironomidae (relative abundance = 73.6±15.4%; mean±SE; n = 15). Invertebrate biomass and mean body size differed among watersheds (biomass, F2,12 = 3.89, p = 0.050; body size, F2,12 = 6.12, p = 0.015). However, at this broad spatial scale, BOM quantity and quality had little effect on invertebrate community metrics in sand habitats. BOM content of sand habitats likely represents one factor, among many components of this dynamic habitat, which shapes overall macroinvertebrate communities.

Yamamuro, A. M.; Miesbauer, J. M.; Lamberti, G. A.

2005-05-01

301

Size of nature reserves: densities of large trees and dead wood indicate high value of small conservation forests in southern Sweden  

Microsoft Academic Search

The optimal size of nature reserves has been debated for some time. Although edge and core habitats are often recognized, it is commonly assumed in theory and in studies of a particular habitat type that reserves or patches of different sizes have similar habitat structure. However, for older, highly fragmented landscapes it has been suggested that small areas are of

Frank Götmark; Maria Thorell

2003-01-01

302

Role Habitat Fragmentation in the Structure and Function of Seagrass Ecosystems in the Northern Gulf of Mexico.  

National Technical Information Service (NTIS)

The role of changes in patch size and shape (habitat fragmentation) on ecological processes of seagrass meadows is poorly understood. Most research to date has resulted in equivocal findings that are confined to a general description of community structur...

M. W. Johnson

2004-01-01

303

Risky prey behavior evolves in risky habitats.  

PubMed

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

Urban, Mark C

2007-08-27

304

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

USGS Publications Warehouse

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

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

2008-01-01

305

Habitat associations of juvenile versus adult butterflyfishes  

NASA Astrophysics Data System (ADS)

Many coral reef fishes exhibit distinct ontogenetic shifts in habitat use while some species settle directly in adult habitats, but there is not any general explanation to account for these differences in settlement strategies among coral reef fishes. This study compared distribution patterns and habitat associations of juvenile (young of the year) butterflyfishes to those of adult conspecifics. Three species, Chaetodon auriga, Chaetodon melannotus, and Chaetodon vagabundus, all of which have limited reliance on coral for food, exhibited marked differences in habitat association of juvenile versus adult individuals. Juveniles of these species were consistently found in shallow-water habitats, whereas adult conspecifics were widely distributed throughout a range of habitats. Juveniles of seven other species ( Chaetodon aureofasciatus, Chaetodon baronessa, Chaetodon citrinellus, Chaetodon lunulatus, Chaetodon plebeius, Chaetodon rainfordi, and Chaetodon trifascialis), all of which feed predominantly on live corals, settled directly into habitat occupied by adult conspecifics. Butterflyfishes with strong reliance on corals appear to be constrained to settle in habitats that provide access to essential prey resources, precluding their use of distinct juvenile habitats. More generalist butterflyfishes, however, appear to utilize distinct juvenile habitats and exhibit marked differences in the distribution of juveniles versus adults.

Pratchett, M. S.; Berumen, M. L.; Marnane, M. J.; Eagle, J. V.; Pratchett, D. J.

2008-09-01

306

Invasions in heterogeneous habitats in the presence of advection.  

PubMed

We investigate invasions from a biological reservoir to an initially empty, heterogeneous habitat in the presence of advection. The habitat consists of a periodic alternation of favorable and unfavorable patches. In the latter the population dies at fixed rate. In the former it grows either with the logistic or with an Allee effect type dynamics, where the population has to overcome a threshold to grow. We study the conditions for successful invasions and the speed of the invasion process, which is numerically and analytically investigated in several limits. Generically advection enhances the downstream invasion speed but decreases the population size of the invading species, and can even inhibit the invasion process. Remarkably, however, the rate of population increase, which quantifies the invasion efficiency, is maximized by an optimal advection velocity. In models with Allee effect, differently from the logistic case, above a critical unfavorable patch size the population localizes in a favorable patch, being unable to invade the habitat. However, we show that advection, when intense enough, may activate the invasion process. PMID:22381537

Vergni, Davide; Iannaccone, Sandro; Berti, Stefano; Cencini, Massimo

2012-02-23

307

Clockwork: Hands On For Habitat  

NSDL National Science Digital Library

Clockwork is "a self directed, theatre-based education package about biological diversity." Produced by Vox Bandicoot in collaboration with the Biodiversity Group (Environment Australia), the Clockwork site offers four sections: Midnight, an introduction to and philosophy of biological diversity, Mainspring, a hands-on lesson in critical concepts about threatened species and habitats, Big Hand and Little Hand, curriculum support material for classroom teachers, and Cog and Spindle, general science and ecological background about Australia. Though depth of content varies, environmental educators will be interested in this fresh and creative approach.

Bandicoot., Vox

1997-01-01

308

Rapid viability analysis for metapopulations in dynamic habitat networks.  

PubMed

For land-use planning, numerically fast and easily applicable tools are urgently needed that allow us to assess how landscape structure and dynamics affect biodiversity. To date, such tools exist only for static landscapes. We provide an analytical formula for the mean lifetime of species in fragmented and dynamic habitat networks where habitat patches may be destroyed and created elsewhere. The formula is able to consider both patch size heterogeneity and dynamics additionally to patch number and connectivity. It is validated through comparison with a dynamic and spatially explicit simulation model. It can be used for the optimization of spatio-temporal land-use patterns in real landscapes and for advancing our general understanding of key processes affecting the survival of species in fragmented heterogeneous dynamic landscapes. PMID:20164097

Drechsler, Martin; Johst, Karin

2010-02-17

309

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

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

310

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.

Johnstone, Christopher P.; Lill, Alan; Reina, Richard D.

2011-01-01

311

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

312

Size structure of the metazoan community in a Piedmont stream  

Microsoft Academic Search

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

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

1993-01-01

313

Forest Bird Habitat Suitability Models and the Development of General Habitat Models.  

National Technical Information Service (NTIS)

Habitat Suitability Index (HSI) models were developed to assess the sensitivity of wildlife to habitat perturbations. Because most models consider a single species, their generality is limited. We evaluate the feasibility of combining such models for spec...

B. Van Horne J. A. Wiens

1991-01-01

314

Elevation Derivatives for Mojave Desert Tortoise Habitat  

USGS Publications Warehouse

This report describes the methods used to derive various elevation-derivative grids that were inputted to the Mojave Desert Tortoise Habitat model (L. Gass and others, unpub. data). These grids, which capture information on surface roughness and topographic characteristics, are a subset of the environmental datasets evaluated for the tortoise habitat model. This habitat model is of major importance to the U.S. Fish and Wildlife Service, which is charged with management of this threatened population, including relocating displaced tortoises to areas identified as suitable habitat.

Wallace, Cynthia S. A.; Gass, Leila

2008-01-01

315

Extreme contagion in global habitat clearance  

PubMed Central

Habitat clearance remains the major cause of biodiversity loss, with consequences for ecosystem services and for people. In response to this, many global conservation schemes direct funds to regions with high rates of recent habitat destruction, though some also emphasize the conservation of remaining large tracts of intact habitat. If the pattern of habitat clearance is highly contagious, the latter approach will help prevent destructive processes gaining a foothold in areas of contiguous intact habitat. Here, we test the strength of spatial contagion in the pattern of habitat clearance. Using a global dataset of land-cover change at 50 × 50 km resolution, we discover that intact habitat areas in grid cells are refractory to clearance only when all neighbouring cells are also intact. The likelihood of loss increases dramatically as soon as habitat is cleared in just one neighbouring cell, and remains high thereafter. This effect is consistent for forests and grassland, across biogeographic realms and over centuries, constituting a coherent global pattern. Our results show that landscapes become vulnerable to wholesale clearance as soon as threatening processes begin to penetrate, so actions to prevent any incursions into large, intact blocks of natural habitat are key to their long-term persistence.

Boakes, Elizabeth H.; Mace, Georgina M.; McGowan, Philip J. K.; Fuller, Richard A.

2010-01-01

316

Extreme contagion in global habitat clearance.  

PubMed

Habitat clearance remains the major cause of biodiversity loss, with consequences for ecosystem services and for people. In response to this, many global conservation schemes direct funds to regions with high rates of recent habitat destruction, though some also emphasize the conservation of remaining large tracts of intact habitat. If the pattern of habitat clearance is highly contagious, the latter approach will help prevent destructive processes gaining a foothold in areas of contiguous intact habitat. Here, we test the strength of spatial contagion in the pattern of habitat clearance. Using a global dataset of land-cover change at 50 x 50 km resolution, we discover that intact habitat areas in grid cells are refractory to clearance only when all neighbouring cells are also intact. The likelihood of loss increases dramatically as soon as habitat is cleared in just one neighbouring cell, and remains high thereafter. This effect is consistent for forests and grassland, across biogeographic realms and over centuries, constituting a coherent global pattern. Our results show that landscapes become vulnerable to wholesale clearance as soon as threatening processes begin to penetrate, so actions to prevent any incursions into large, intact blocks of natural habitat are key to their long-term persistence. PMID:19939838

Boakes, Elizabeth H; Mace, Georgina M; McGowan, Philip J K; Fuller, Richard A

2009-11-25

317

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

318

Subseafloor basalts as fungal habitats  

NASA Astrophysics Data System (ADS)

The oceanic crust is believed to host the largest potential habitat for microbial life on Earth, yet, next to nothing is known about this deep, concealed biosphere. Here fossilised fungal colonies in subseafloor basalts are reported from three different seamounts in the Pacific Ocean. The fungal colonies consist of various characteristic structures interpreted as fungal hyphae, fruit bodies and spores. The fungal hyphae are well preserved with morphological characteristics such as hyphal walls, septa, thallic conidiogenesis, and hyphal tips with hyphal vesicles within. The fruit bodies consist of large (~50-200 ?m in diameter) body-like structures with a defined outer membrane and an interior filled with calcite. The fruit bodies have at some stage been emptied of their contents of spores and filled by carbonate forming fluids. A few fruit bodies not filled by calcite and with spores still within support this interpretation. Spore-like structures (ranging from a few ?m:s to ∼20 ?m in diameter) are also observed outside of the fruit bodies and in some cases concentrated to openings in the membrane of the fruit bodies. The hyphae, fruit bodies and spores are all closely associated with a crust lining the vein walls that probably represent a mineralized biofilm. The results support a fungal presence in deep subseafloor basalts and indicate that such habitats were vital between ∼81 and 48 Ma, and probably still is. It is suggested that near future ocean drilling programs prioritize sampling of live species to better understand this concealed biosphere.

Ivarsson, M.

2012-02-01

319

Class Size.  

ERIC Educational Resources Information Center

|The items featured in this annotated bibliography touch on several aspects of the multifaceted class-size debate. Allen Odden reviews the literature and contends that class-size reduction should be used "sparingly and strategically." C. M. Achilles and colleagues examines two different class-size situations and find student test performance in…

Underwood, Siobhan; Lumsden, Linda S.

1994-01-01

320

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...

321

Habitat cascades: the conceptual context and global relevance of facilitation cascades via habitat formation and modification.  

PubMed

The importance of positive interactions is increasingly acknowledged in contemporary ecology. Most research has focused on direct positive effects of one species on another. However, there is recent evidence that indirect positive effects in the form of facilitation cascades can also structure species abundances and biodiversity. Here we conceptualize a specific type of facilitation cascade-the habitat cascade. The habitat cascade is defined as indirect positive effects on focal organisms mediated by successive facilitation in the form of biogenic formation or modification of habitat. Based on a literature review, we demonstrate that habitat cascades are a general phenomenon that enhances species abundance and diversity in forests, salt marshes, seagrass meadows, and seaweed beds. Habitat cascades are characterized by a hierarchy of facilitative interactions in which a basal habitat former (typically a large primary producer, e.g., a tree) creates living space for an intermediate habitat former (e.g., an epiphyte) that in turn creates living space for the focal organisms (e.g., spiders, beetles, and mites). We then present new data on a habitat cascade common to soft-bottom estuaries in which a relatively small invertebrate provides basal habitat for larger intermediate seaweeds that, in turn, generate habitat for focal invertebrates and epiphytes. We propose that indirect positive effects on focal organisms will be strongest when the intermediate habitat former is larger and different in form and function from the basal habitat former. We also discuss how humans create, modify, and destroy habitat cascades via global habitat destruction, climatic change, over-harvesting, pollution, or transfer of invasive species. Finally, we outline future directions for research that will lead to a better understanding of habitat cascades. PMID:21558196

Thomsen, Mads S; Wernberg, Thomas; Altieri, Andrew; Tuya, Fernando; Gulbransen, Dana; McGlathery, Karen J; Holmer, Marianne; Silliman, Brian R

2010-05-11

322

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

323

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

324

Endolithic Microbial Communities in Polar Desert Habitats  

Microsoft Academic Search

Microorganisms inhabiting terrestrial endolithic habitats are widespread in polar environments including the Antarctic Dry Valleys and the Canadian high Arctic. Their ability to survive in these harsh environments is a result of their finding protection from extremes in temperature, aridity, radiation and winds by colonizing nutrient-rich subsurface habitats that provide more amenable conditions for growth, often developing as vertically stratified

Christopher R. Omelon

2008-01-01

325

Trends in Methods for Assessing Freshwater Habitats  

Microsoft Academic Search

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

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

1999-01-01

326

Indirect effect of habitat destruction on ecosystems  

Microsoft Academic Search

Habitat destruction is one of the primary causes of species extinction in recent history. Even if the destruction is restricted to a local and small area, its accumulation increases the risk of extinction. To study local destruction of habitat, we present a lattice ecosystem composed of prey (X) and predator (Y). This system corresponds to a lattice version of the

N. Nakagiri; K. Tainaka

327

Fish Habitat Compensation Projects along Yukon Highways  

Microsoft Academic Search

Under the Fisheries Act, highway construction projects that result in harmful disruption or destruction of fish habitat require replacement habitat. At Yukon Highways & Public Works we have developed successful compensation projects together with the Department of Fisheries and Oceans, and in many cases with the help of consultants. This paper describes three Yukon examples. The first project describes the

Toos Omtzigt; Pat Tobler; R. P Bio

328

Habitat selection models for European wildcat conservation  

Microsoft Academic Search

Populations of the European wildcat (Felis silvestris) are only slowly recovering in Central Europe after a severe decline in the last centuries and require specific conservation plans in many areas. However, detailed information on wildcat occurrence and habitat requirements is still scarce and controversial. We present a fine-scale habitat selection model for wildcats based on detailed species and land use

Nina Klar; Néstor Fernández; Stephanie Kramer-Schadt; Mathias Herrmann; Manfred Trinzen; Ingrid Büttner; Carsten Niemitz

2008-01-01

329

Habitat Suitability Index Models: Fox Squirrel.  

National Technical Information Service (NTIS)

Habitat preferences and species characteristics of the fox squirrel(Sciurus niger) are described in this publication. It is one of a series of Habitat Suitability Index (HSI) models and was developed through an analysis of available scientific data on the...

A. W. Allen

1982-01-01

330

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.

331

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

332

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...

333

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

334

How Habitat Edges Change Species Interactions  

Microsoft Academic Search

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

William F. Fagan; Robert Stephen Cantrell; Chris Cosner

1999-01-01

335

Habitat fragmentation resulting in overgrazing by herbivores  

Microsoft Academic Search

Habitat fragmentation sometimes results in outbreaks of herbivorous insect and causes an enormous loss of primary production. It is hypothesized that the driving force behind such herbivore outbreaks is disruption of natural enemy attack that releases herbivores from top-down control. To test this hypothesis I studied how trophic community structure changes along a gradient of habitat fragmentation level using spatially

Michio Kondoh

2003-01-01

336

Habitat Management for Birds of West Virginia.  

National Technical Information Service (NTIS)

This report is a synthesis of existing literature and survey data for West Virginia birds. The objectives of this report are to summarize available bird population data for major habitat types in West Virginia, to indicate how changes in habitat influence...

S. H. Anderson C. S. Robbins J. R. Partelow

1981-01-01

337

COASTAL SUBMERGED VEGETATION: AQUATIC HABITAT RESEARCH  

EPA Science Inventory

Aquatic vegetation is one of the most widespread and important types of aquatic habitat, in part because of the exceptional productivity of the plants. Aquatic vegetation also strongly influences local physical and chemical habitat conditions of significance to fish and shellfis...

338

Willow Planting for Riparian Habitat Improvement.  

National Technical Information Service (NTIS)

Riparian zones are one of the most important and sensitive of all habitats on public lands. They provide a variety of habitat components that are essential to many species of wildlife. This report is designed for field personnel who are interested in empl...

D. C. McCluskey D. Bornholdt D. A. Duff A. H. Winward J. Brown

1983-01-01

339

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…

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

340

50 CFR 226.208 - Critical habitat for green turtle.  

Code of Federal Regulations, 2010 CFR

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

2010-10-01

341

50 CFR 226.208 - Critical habitat for green turtle.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false Critical habitat for green turtle. 226.208 Section 226.208 Wildlife and Fisheries...CRITICAL HABITAT § 226.208 Critical habitat for green turtle. (a) Culebra Island, Puerto...

2009-10-01

342

50 CFR 226.213 - Critical habitat for Johnson's seagrass.  

Code of Federal Regulations, 2010 CFR

...false Critical habitat for Johnson's seagrass. 226.213 Section 226.213 ...213 Critical habitat for Johnson's seagrass. Critical habitat is designated...within the current range of Johnson's seagrass. (a) A portion of the Indian...

2010-10-01

343

50 CFR 226.213 - Critical habitat for Johnson's seagrass.  

Code of Federal Regulations, 2010 CFR

...false Critical habitat for Johnson's seagrass. 226.213 Section 226.213 ...213 Critical habitat for Johnson's seagrass. Critical habitat is designated...within the current range of Johnson's seagrass. (a) A portion of the Indian...

2009-10-01

344

50 CFR 226.214 - Critical habitat for Gulf sturgeon.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Critical habitat for Gulf sturgeon. 226.214 Section 226.214 Wildlife and...HABITAT § 226.214 Critical habitat for Gulf sturgeon. Gulf sturgeon is under the joint jurisdiction of the...

2009-10-01

345

50 CFR 226.214 - Critical habitat for Gulf sturgeon.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Critical habitat for Gulf sturgeon. 226.214 Section 226.214 Wildlife and...HABITAT § 226.214 Critical habitat for Gulf sturgeon. Gulf sturgeon is under the joint jurisdiction of the...

2010-10-01

346

50 CFR 226.213 - Critical habitat for Johnson's seagrass.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Critical habitat for Johnson's seagrass. 226.213...DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.213 Critical habitat for Johnson's seagrass....

2011-10-01

347

50 CFR 424.12 - Criteria for designating critical habitat.  

Code of Federal Regulations, 2010 CFR

... false Criteria for designating critical habitat. 424.12 Section 424...THREATENED SPECIES AND DESIGNATING CRITICAL HABITAT Revision of the Lists § 424.12 Criteria for designating critical habitat. (a) Critical...

2010-10-01

348

50 CFR 424.12 - Criteria for designating critical habitat.  

Code of Federal Regulations, 2010 CFR

... false Criteria for designating critical habitat. 424.12 Section 424...THREATENED SPECIES AND DESIGNATING CRITICAL HABITAT Revision of the Lists § 424.12 Criteria for designating critical habitat. (a) Critical...

2009-10-01

349

50 CFR 226.213 - Critical habitat for Johnson's seagrass.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Critical habitat for Johnson's seagrass. 226.213...DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.213 Critical habitat for Johnson's seagrass....

2012-10-01

350

76 FR 28060 - Regional Habitat Conservation Plan, Hays County, TX  

Federal Register 2010, 2011, 2012, 2013

...benefits to covered species and their habitat, the extent and effectiveness...species will be primarily due to habitat destruction and/or alteration. 2. The applicant...monitoring of species populations and habitat. In addition, the County...

2011-05-13

351

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 and...

2010-10-01

352

50 CFR 660.395 - Essential Fish Habitat (EFH)  

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 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 and...

2009-10-01

353

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

354

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

355

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

Microsoft Academic Search

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

Akihisa Hattori; Miyako Kobayashi

2009-01-01

356

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

Microsoft Academic Search

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

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

1993-01-01

357

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

358

Habitat and roe deer fawn vulnerability to red fox predation.  

PubMed

1. Notwithstanding the growing amount of literature emphasizing the link between habitat, life-history traits and behaviour, few empirical studies investigated the combined effect of these parameters on individual predation risk. We investigated direct and indirect consequences of habitat composition at multiple spatial scales on predation risk by red foxes on 151 radio-monitored roe deer fawns. We hypothesized that the higher resource availability in fragmented agricultural areas increased predation risk because of: (i) shorter prey movements, which may increase predictability; (ii) larger litter size and faster growth rates, which may increase detectability in species adopting a hiding neonatal anti-predator strategy. The sharing of risky habitat among littermates was expected to promote whole-litter losses as a result of predation. 2. The landscape-scale availability of agricultural areas negatively affected pre-weaning movements, but did not influence growth rates or litter size. Predation risk was best described by the interplay between movements and fine-scale habitat fragmentation: a higher mobility increased the encounter rate and predation risk in highly fragmented home ranges, while it reduced predation risk in forest-dominated areas with clumped resources because of decreased predictability. This is one of the first demonstrations that movement patterns can be an efficient anti-predator strategy when adjusted to local conditions. 3. In accordance with previous studies documenting the existence of family effects (i.e. non-independence among siblings) in survival, littermates survived or died together more often than expected by chance. In addition, our study specifically demonstrated the occurrence of behaviourally mediated family effects in predation risk: after a fox killed one fawn the probability of a sibling being killed within a few days rose from 20% to 47%, likely because of the win-stay strategy (i.e. return to a previously rewarding site) adopted by the predator. Hence, the predator's hunting strategy has the potential to raise fawn mortality disproportionately to predator abundance. 4. There is increasing evidence that fawns inhabiting highly productive predator-free habitats are granted lifetime fitness benefits; these potential advantages, however, can be cancelled out when predation risk increases in the very same high-productivity areas, which might thus turn into attractive sinks. PMID:19563469

Panzacchi, M; Linnell, J D C; Odden, M; Odden, J; Andersen, R

2009-06-26

359

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.

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

2011-01-01

360

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

2013-01-16

361

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

362

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.

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

2013-01-01

363

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

364

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

PubMed

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

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

2011-06-01

365

Oviposition habitat selection for a predator refuge and food source in a mosquito  

Microsoft Academic Search

The influence of filamentous algae on oviposition habitat selection by the mosquito Anopheles pseudopunctipennis and the consequences of oviposi- tion decisions on the diet, development, body size, and survival of offspring were examined. 2. A natural population of An. pseudopunctipennis in Chiapas, Mexico, ovi- posited almost exclusively in containers with filamentous algae. Algae represented 47% of the gut contents of

J. G UILLERMO; B OND; J U AN; I. A RREDONDO-JIMENEZ; M A RIO; H. R ODRIGUEZ; H UMBERTO Q UIROZ-MARTINEZ; T REVOR

2005-01-01

366

LANDSCAPE METRICS ASSOCIATED WITH HABITAT USE BY OCELOTS IN SOUTH TEXAS  

Microsoft Academic Search

Ocelots (Leopardus pardalis) are listed as endangered federally and by the state of Texas. Preference for closed canopy habitat has been shown in previous studies, but preference for patch size has not been reported. Geographic Information Systems (GIS) and satellite imagery were used to compare areas in south Texas used by radio-collared ocelots to areas with no known use. We

VICTORIA L. JACKSON; LINDA L. LAACK; EARL G. ZIMMERMAN; Gehrt

2005-01-01

367

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

Microsoft Academic Search

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

Bret C. Harvey

1991-01-01

368

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...

369

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

Microsoft Academic Search

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

Richard Wahle; Robert Steneck

1991-01-01

370

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

371

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

2012-12-14

372

Spatial distribution and habitat characterization of anopheline mosquito larvae in Western Kenya.  

PubMed

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 the shore of Lake Victoria, coverage of canopy, surface debris, algae and emergent plants, turbidity, substrate, and habitat types. Microscopic identification of third- and fourth-instar anopheline larvae did not yield any Anopheles funestus or other anophelines. A total of 829 An. gambiae s.l. larvae from all habitats were analyzed further by rDNA-polymerase chain reaction to identify individual species within the An. gambiae species complex. Overall, An. arabiensis was the predominant species (63.4%), and An. gambiae was less common (31.4%). The species composition of An. gambiae s.l. varied significantly among the sampling sites throughout Suba District. The larval habitats in the southern area of the district had a higher proportion of An. gambiae than in the northern area. Multiple logistic analysis did not detect any significant association between the occurrence of anopheline larvae and habitat variables, and principal component analysis did not identify key environmental factors associated with the abundance of An. gambiae. However, significant spatial heterogeneity in the relative abundance of An. gambiae within the Suba district was detected. When the effect of larval habitat locality was considered in the analysis, we found that the distance to the nearest house and substrate type were significantly associated with the relative abundance of An. gambiae. Future studies integrating detailed water chemistry analysis, remote sensing technology, and the ecology of predators may be required to further elucidate the mechanisms underlying the observed spatial variation of anopheline larval distribution. PMID:10674687

Minakawa, N; Mutero, C M; Githure, J I; Beier, J C; Yan, G

1999-12-01

373

Meta-analysis of susceptibility of woody plants to loss of genetic diversity through habitat fragmentation.  

PubMed

Shrubs and trees are assumed less likely to lose genetic variation in response to habitat fragmentation because they have certain life-history characteristics such as long lifespans and extensive pollen flow. To test this assumption, we conducted a meta-analysis with data on 97 woody plant species derived from 98 studies of habitat fragmentation. We measured the weighted response of four different measures of population-level genetic diversity to habitat fragmentation with Hedge's d and Spearman rank correlation. We tested whether the genetic response to habitat fragmentation was mediated by life-history traits (longevity, pollination mode, and seed dispersal vector) and study characteristics (genetic marker and plant material used). For both tests of effect size habitat fragmentation was associated with a substantial decrease in expected heterozygosity, number of alleles, and percentage of polymorphic loci, whereas the population inbreeding coefficient was not associated with these measures. The largest proportion of variation among effect sizes was explained by pollination mechanism and by the age of the tissue (progeny or adult) that was genotyped. Our primary finding was that wind-pollinated trees and shrubs appeared to be as likely to lose genetic variation as insect-pollinated species, indicating that severe habitat fragmentation may lead to pollen limitation and limited gene flow. In comparison with results of previous meta-analyses on mainly herbaceous species, we found trees and shrubs were as likely to have negative genetic responses to habitat fragmentation as herbaceous species. We also found that the genetic variation in offspring was generally less than that of adult trees, which is evidence of a genetic extinction debt and probably reflects the genetic diversity of the historical, less-fragmented landscape. PMID:22044646

Vranckx, Guy; Jacquemyn, Hans; Muys, Bart; Honnay, Olivier

2011-11-01

374

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

375

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

376

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

377

Size detectors  

Microsoft Academic Search

An edge separation method of detecting one-dimensional objects in a given size range is described, and its capabilities contrasted with those of the conventional linear matched filter approach to object detection.

C. M. Cook; A. Rosenfeld

1970-01-01

378

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.

2011-01-01

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

Density-dependent habitat selection and performance by a large mobile reef fish.  

PubMed

Many exploited reef fish are vulnerable to overfishing because they concentrate over hard-bottom patchy habitats. How mobile reef fish use patchy habitat, and the potential consequences on demographic parameters, must be known for spatially explicit population dynamics modeling, for discriminating essential fish habitat (EFH), and for effectively planning conservation measures (e.g., marine protected areas, stock enhancement, and artificial reefs). Gag, Mycteroperca microlepis, is an ecologically and economically important warm-temperate grouper in the southeastern United States, with behavioral and life history traits conducive to large-scale field experiments. The Suwannee Regional Reef System (SRRS) was built of standard habitat units (SHUs) in 1991-1993 to manipulate and control habitat patchiness and intrinsic habitat quality, and thereby test predictions from habitat selection theory. Colonization of the SRRS by gag over the first six years showed significant interactions of SHU size, spacing, and reef age; with trajectories modeled using a quadratic function for closely spaced SHUs (25 m) and a linear model for widely spaced SHUs (225 m), with larger SHUs (16 standardized cubes) accumulating significantly more gag faster than smaller 4-cube SHUs (mean = 72.5 gag/16-cube SHU at 225-m spacing by year 6, compared to 24.2 gag/4-cube SHU for same spacing and reef age). Residency times (mean = 9.8 mo), indicative of choice and measured by ultrasonic telemetry (1995-1998), showed significant interaction of SHU size and spacing consistent with colonization trajectories. Average relative weight (W(r)) and incremental growth were greater on smaller than larger SHUs (mean W(r) = 104.2 vs. 97.7; incremental growth differed by 15%), contrary to patterns of abundance and residency. Experimental manipulation of shelter on a subset of SRRS sites (2000-2001) confirmed our hypothesis that shelter limits local densities of gag, which, in turn, regulates their growth and condition. Density-dependent habitat selection for shelter and individual growth dynamics were therefore interdependent ecological processes that help to explain how patchy reef habitat sustains gag production. Moreover, gag selected shelter at the expense of maximizing their growth. Thus, mobile reef fishes could experience density-dependent effects on growth, survival, and/or reproduction (i.e., demographic parameters) despite reduced stock sizes as a consequence of fishing. PMID:16711059

Lindberg, William J; Frazer, Thomas K; Portier, Kenneth M; Vose, Frederic; Loftin, James; Murie, Debra J; Mason, Doran M; Nagy, Brian; Hart, Mary K

2006-04-01

381

Habitat as a Basis for Environmental Assessment.  

National Technical Information Service (NTIS)

The ecological concepts and legislative rationale in support of the Habitat Evaluation Procedures (HEP) are described. Legislation addressing fish and wildlife aspects of environmental impact assessment are generally framed around four approaches of speci...

1980-01-01

382

Ecological risk of aquatic habitat degradation.  

National Technical Information Service (NTIS)

Habitat degradation constitutes a significant risk to the biotic integrity of freshwater ecosystems, especially streams and rivers. The degradation can result from any action that alters the physical or chemical attributes of a stream, thus reducing its u...

J. M. Loar

1991-01-01

383

Subsurface Microbial Habitats on Mars (Abstract Only).  

National Technical Information Service (NTIS)

We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on...

P. J. Boston C. P. Mckay

1991-01-01

384

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

385

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

386

Habitat destruction and the extinction debt revisited  

SciTech Connect

A very important analysis of the problem of habitat destruction concluded that such destruction may lead to an extinction debt, which is the irreversible loss of species following a prolonged transient or delay. An error in interpretation of this model led the authors to apply the results to all types of habitat destruction, but in fact the model applies only to an across-the-board decrease in fecundity, not to disturbances. For repeated, spatially random disturbance, a different model applies. For habitat destruction on regional scales (reduction in ecosystem area without disturbance in remnant areas), one must, in contrast, apply species-area relations based on the distribution of different habitat types (e.g., elevational and rainfall gradients, physiographic and edaphic variability). The error in interpretation of the basic model is presented, followed by clarification of model usage and development of a new model that applies to disturbance events.

Loehle, C.

1996-02-01

387

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...

388

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...

389

map showing predicted habitat potentional for tortoise  

USGS Multimedia Gallery

This map shows the spatial representation of the predicted habitat potential index values for desert tortoise in the Mojave and parts of the Sonoran Deserts of California, Nevada, Utah, and Arizona. Map: USGS. ...

2009-05-21

390

Geography Action! Habitats: Home Sweet Home  

NSDL National Science Digital Library

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

391

Seniors for Habitat Effective Practices Manual.  

National Technical Information Service (NTIS)

Table of Contents: Introduction; (Chapter 1) Seniors for Habitat 101; (Chapter 2) Partners in Building Homes; (Chapter 3) Recruitment, Retention, and Recognition; (Chapter 4) Training and Development; (Chapter 5) Matching the Right Volunteer With the Righ...

2001-01-01

392

Evolution of extreme body size disparity in monitor lizards (Varanus).  

PubMed

Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards. PMID:21884063

Collar, David C; Schulte, James A; Losos, Jonathan B

2011-05-25

393

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

2009-01-23

394

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

395

Habitat split leads to biodiversity decline  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (AAAS;)

2007-12-13

396

Breeding canvasbacks: a test of a habitat model  

USGS Publications Warehouse

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

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

1989-01-01

397

The effect of conspecifics on habitat selection in territorial species  

Microsoft Academic Search

Summary Despite widespread interest in habitat selection, many of the assumptions about how territorial animals choose habitats have not been tested. This study of juvenile Anolis aeneus lizards focuses on the relationship between the number of previous settlers in a habitat and the subsequent behavior of new arrivals at that habitat. Clearings containing the types of microhabitat preferred by juveniles

J. A. Stamps

1991-01-01

398

BLACK BEAR HABITAT USE AT PRIEST LAKE, IDAHO  

Microsoft Academic Search

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

D. D. YOUNG; J. J. BEECHAM

399

Habitat connectivity and fragmented nuthatch populations in agricultural landscapes  

Microsoft Academic Search

In agricultural landscapes, the habitat of many species is subject to fragmentation. When the habitat of a species is fragmented and the distances between patches of habitat are large relative to the movement distances of the species, it can be expected that the degree of habitat connectivity affects processes at population and individual level. In this thesis, I report on

Langevelde van F

1999-01-01

400

Fish Assemblage Relationships with Physical Habitat in Wadeable Iowa Streams  

Microsoft Academic Search

Fish assemblages play a key role in stream ecosystems and are influenced by physical habitat. We analyzed fish assemblages and physical habitat at 93 randomly selected sites on second- through fifth-order wadeable Iowa streams to explore fish assemblage relationships with reach-scale physical habitat in this agriculturally dominated landscape. Sites were sampled using DC electrofishing and the wadeable streams physical habitat

David C. Rowe; Clay L. Pierce; Thomas F. Wilton

2009-01-01

401

Effectiveness of Habitat Manipulation for Wild Salmonids in Wyoming Streams  

Microsoft Academic Search

Habitat manipulation is commonly used to enhance habitat and stocks of fluvial trout of the genera Oncorhynchus, Salmo, and Salvelinus, but questions have been raised about the effectiveness of such work. Consequently, I analyzed wild trout abundance, biomass, and habitat before and after habitat manipulations among 30 projects done by the Wyoming Game and Fish Department. Abundance and biomass of

N. Allen Binns

2004-01-01

402

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

403

Populations can persist in an en' habitats only  

Microsoft Academic Search

Populations that live in environments with different habitats have to distribute their offspring over these habitats. When population densities go to equilibrium, the evolutionary optimum is an ideal free distribution. Under an ideal free distribution, no offspring should be put into sink habitats. However, when the environmental conditions in a habitat are not constant but fluctuate, allocating offspring to sink

VINCENT A. A. JANSEN; JIN YOSHIMURA

1998-01-01

404

MIGRATING SHOREBIRDS AND HABITAT DYNAMICS AT A PRAIRIE WETLAND COMPLEX  

Microsoft Academic Search

ABSTFCAC~. - We examined the responses of migrating shorebirds to habitat dynamics in a wetland complex on the Great Plains during 1989-1992. Availability of habitat was variable within and between seasons, but fluctuations in habitat were dampened when wetlands were considered as a complex rather than individually. Shorebirds exhibited an ability to colonize available habitat opportunistically, to occupy wet mud\\/shallow

SUSAN K. SKAGEN; FRITZ L. KNOPF

405

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

406

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

407

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

USGS Publications Warehouse

A review and synthesis of existing information were used to develop a model for evaluating wintering habitat quality for northern pintail (Anas acuta) along the Gulf of Mexico coast. The model is scaled to produce an index between unsuitable habitat) and 1.0 (optimal habitat). Habitat suitability index models are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for model application and techniques for measuring model variables are provided.

Howard, Rebecca J.; Kantrud, Harold A.

1986-01-01

408

Exploring Size.  

ERIC Educational Resources Information Center

|"Exploring" is a magazine of science, art, and human perception that communicates ideas museum exhibits cannot demonstrate easily by using experiments and activities for the classroom. This issue concentrates on size, examining it from a variety of viewpoints. The focus allows students to investigate and discuss interconnections among apparently…

Brand, Judith, Ed.

1995-01-01

409

Size matters  

Microsoft Academic Search

One effect of the interdependencies fuelled by globalization and new communication technologies is the disappearance of a stable sense of the size of the world and our location in it. This article looks at a number of attempts to cognitively remap the world by scaling it down to more manageable proportions, drawing on examples from anthropology, cosmopolitan discourse, Hollywood film

Nicola Evans

2005-01-01

410

Aggregative response in bats: prey abundance versus habitat.  

PubMed

In habitats where prey is either rare or difficult to predict spatiotemporally, such as open habitats, predators must be adapted to react effectively to variations in prey abundance. Open-habitat foraging bats have a wing morphology adapted for covering long distances, possibly use information transfer to locate patches of high prey abundance, and would therefore be expected to show an aggregative response at these patches. Here, we examined the effects of prey abundance on foraging activities of open-habitat foragers in comparison to that of edge-habitat foragers and closed-habitat foragers. Bat activity was estimated by counting foraging calls recorded with bat call recorders (38,371 calls). Prey abundance was estimated concurrently at each site using light and pitfall traps. The habitat was characterized by terrestrial laser scanning. Prey abundance increased with vegetation density. As expected, recordings of open-habitat foragers clearly decreased with increasing vegetation density. The foraging activity of edge- and closed-habitat foragers was not significantly affected by the vegetation density, i.e., these guilds were able to forage from open habitats to habitats with dense vegetation. Only open-habitat foragers displayed a significant and proportional aggregative response to increasing prey abundance. Our results suggest that adaptations for effective and low-cost foraging constrains habitat use and excludes the guild of open-habitat foragers from foraging in habitats with high prey abundance, such as dense forest stands. PMID:22218944

Müller, Jörg; Mehr, Milenka; Bässler, Claus; Fenton, M Brock; Hothorn, Torsten; Pretzsch, Hans; Klemmt, Hans-Joachim; Brandl, Roland

2012-01-05

411

Influence of habitat degradation on fish replenishment  

NASA Astrophysics Data System (ADS)

Temperature-induced coral bleaching is a major threat to the biodiversity of coral reef ecosystems. While reductions in species diversity and abundance of fish communities have been documented following coral bleaching, the mechanisms that underlie these changes are poorly understood. The present study examined the impacts of coral bleaching on the early life-history processes of coral reef fishes. Daily monitoring of fish settlement patterns found that ten times as many fish settled to healthy coral than sub-lethally bleached coral. Species diversity of settling fishes was least on bleached coral and greatest on dead coral, with healthy coral having intermediate levels of diversity. Laboratory experiments using light-trap caught juveniles showed that different damselfish species chose among healthy, bleached and dead coral habitats using different combinations of visual and olfactory cues. The live coral specialist, Pomacentrus moluccensis, preferred live coral and avoided bleached and dead coral, using mostly visual cues to inform their habitat choice. The habitat generalist, Pomacentrus amboinensis, also preferred live coral and avoided bleached and dead coral but selected these habitats using both visual and olfactory cues. Trials with another habitat generalist, Dischistodus sp., suggested that vision played a significant role. A 20 days field experiment that manipulated densities of P. moluccensis on healthy and bleached coral heads found an influence of fish density on juvenile weight and growth, but no significant influence of habitat quality. These results suggests that coral bleaching will affect settlement patterns and species distributions by influencing the visual and olfactory cues that reef fish larvae use to make settlement choices. Furthermore, increased fish density within the remaining healthy coral habitats could play an important role in influencing population dynamics.

McCormick, M. I.; Moore, J. A. Y.; Munday, P. L.

2010-09-01

412

No Net Loss of Fish Habitat: A Review and Analysis of Habitat Compensation in Canada  

Microsoft Academic Search

The achievement of No Net Loss (NNL) through habitat compensation has rarely been assessed in Canada. Files relating to 124 Fisheries Act Section 35(2) authorizations issued by Fisheries and Oceans Canada for the harmful alteration, disruption, and destruction of fish habitat (HADD) were collected and reviewed. Data extracted from these files were pooled and analyzed to provide an indication of

D. J. Harper; J. T. Quigley

2005-01-01

413

Habitat Deterioration, Habitat Destruction, and Metapopulation Persistence in a Heterogenous Landscape  

Microsoft Academic Search

Levins's unstructured metapopulation model predicts that the equilibrium fraction of empty habitat patches is a constant function of the fractionhof suitable patches in the landscape and that this constant equals the threshold value for metapopulation persistence. Levins's model thus suggests that the minimum amount of suitable habitat necessary for metapopulation persistence can be estimated from the fraction of empty patches

Mats Gyllenberg; Ilkka Hanski

1997-01-01

414

Identifying Fish Habitats: the use of spatially explicit habitat modeling and prediction in marine research  

Microsoft Academic Search

New methods of optimally identifying and predicting marine habitat occurrence are needed to help best address management issues such as marine reserve designation, fisheries stock assessment and aquaculture planning across large areas. A combination of video sampling, acoustic remote sensing and learning-based classification methods are proposed as a means of optimally identifying marine habitats. More commonly used in the identification

Katrina Baxter; Mark Shortis

415

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

EPA Science Inventory

A principal challenge of species conservation is to identify the specific habitats that are essential for long-term persistence or recovery of imperiled species. However, many approaches to identifying important habitats do not provide direct insight into the contribution of hab...

416

Organism responses to habitat fragmentation and diversity: Habitat colonization by estuarine macrofauna  

Microsoft Academic Search

Ecologists increasingly recognize that their choice of spatial scales may influence greatly their interpretation of ecological systems, and that small changes in the patchiness of habitat resources can produce abrupt, sometimes dramatic shifts in distribution and abundance patterns of a species. Moreover, identification of scale- and habitat-dependent ecological patterns are central to management efforts aimed at predicting the response of

David B Eggleston; Ward E Elis; Lisa L Etherington; Craig P Dahlgren; Martin H Posey

1999-01-01

417

CTUIR Umatilla Anadromous Fisheries Habitat Project : A Columbia River Basin Fish Habitat Project 2008 Annual Report  

Microsoft Academic Search

The Umatilla Anadromous Fisheries Habitat Project (UAFHP) is an ongoing effort to protect, enhance, and restore riparian and instream habitat for the natural production of anadromous salmonids in the Umatilla River Basin, Northeast Oregon. Flow quantity, water temperature, passage, and lack of in-stream channel complexity have been identified as the key limiting factors in the basin. During the 2008 Fiscal

Eric D. Hoverson; Alexandra Amonette

2009-01-01

418

How individual movement response to habitat edges affects population persistence and spatial spread.  

PubMed

How individual-level movement decisions in response to habitat edges influence population-level patterns of persistence and spread of a species is a major challenge in spatial ecology and conservation biology. Here, we integrate novel insights into edge behavior, based on habitat preference and movement rates, into spatially explicit growth-dispersal models. We demonstrate how crucial ecological quantities (e.g., minimal patch size, spread rate) depend critically on these individual-level decisions. In particular, we find that including edge behavior properly in these models gives qualitatively different and intuitively more reasonable results than those of some previous studies that did not consider this level of detail. Our results highlight the importance of new empirical work on individual movement response to habitat edges. PMID:23778225

Maciel, Gabriel Andreguetto; Lutscher, Frithjof

2013-05-15

419

Spatial and temporal shifts in suitable habitat of juvenile southern flounder (Paralichthys lethostigma)  

NASA Astrophysics Data System (ADS)

Factors influencing suitable habitats of juvenile southern flounder (Paralichthys lethostigma) within the Galveston Bay Complex (GBC), Texas, were assessed using generalized additive models (GAM). Fishery independent data collected with bag seines throughout the GBC from 1999 to 2009 were used to predict the probability of southern flounder occurrence. Binomial GAMs were used to assess presence/absence of southern flounder and models included temporal variables, benthic variables such as distance to habitats generated within a geographic information system, and physicochemical conditions of the water column. Separate models were generated for newly settled southern flounder, young-of-the-year (YOY) southern flounder observed in the summer, and YOY southern flounder observed in fall based on size and collection month. Factors affecting southern flounder occurrence changed seasonally, as did the corresponding shifts in the spatial distribution of suitable habitat. Temporal effects (year and month) were retained in all models. Physicochemical conditions (temperature, turbidity, and measures of environmental variability), and the presence of seagrass beds were influential for newly settled southern flounder. Distance to marine and/or freshwater sources were found to be important for YOY southern flounder in the summer and fall seasons. The abundance of brown shrimp was found to only influence the distribution of YOY southern flounder in the fall, when intermediate abundances of the potential prey item increased the occurrence of southern flounder. After model completion, the availability and spatial distribution of suitable habitat within the GBC was predicted using available environmental and spatial data for 2005. Spatial distributions of predicted suitable habitat stress the relative importance of West Bay during the newly settled stage and in the fall season, and Upper Bay during the summer and fall of the first year of life. These models demonstrate the potential dynamics of suitable habitats for juvenile southern flounder and provide insight into ontogenetic shifts in habitat preference during the first year of life.

Furey, Nathan B.; Rooker, Jay R.

2013-02-01

420

Modeling spatial and temporal variation of suitable nursery habitats for Atlantic sturgeon in the Chesapeake Bay  

NASA Astrophysics Data System (ADS)

For rare and endangered species, bioenergetics modeling can represent a valuable approach for understanding issues of habitat value and connectivity among potential habitats within nurseries in restoration programs. We used multivariable bioenergetics and survival models for Atlantic sturgeon to generate spatially explicit maps of potential production in the Chesapeake Bay. For the period 1993 2002, spatial and temporal patterns in water quality effects (temperature, dissolved oxygen [DO] and salinity) on potential production were evaluated. In addition, two forecasted scenarios were modeled: one implementing newly revised U.S. Environmental Protection Agency (EPA) DO-criteria for the Chesapeake Bay, and the other assuming a bay-wide increase of 1 °C due to an underlying trend in regional climate. Atlantic sturgeon's low (survival/growth) tolerance to temperatures >28 °C was a critical constraint during their first 1 2 summers of life. Hatched in freshwater (spring to mid-summer), young-of-the-year were predicted to occupy cooler (deeper) areas as temperature approached sub-lethal levels. While most thermal refuges were located down-estuary, a large fraction of potential refuges were unsuitable due to persistent hypoxia and/or salinity levels beyond the limited osmoregulatory capabilities of early juvenile Atlantic sturgeon. As a result, suitable summer habitats for juvenile Atlantic sturgeons in the Chesapeake Bay were predicted to be spatially restricted and variable between years, ranging from 0 to 35% of the modeled bay surface area. In critical (drought) years, almost no summer habitat was predicted to be available for juvenile Atlantic sturgeon. Value and size of nursery habitat was highly sensitive to climatic oscillations and anthropogenic interventions affecting freshwater inflow, water temperature and/or DO. Achieving EPA DO-criteria for the Chesapeake Bay was predicted to increase total suitable habitat by 13% for an average year, while increasing water temperature by just 1 °C bay-wide would reduce suitable habitat by 65%.

Niklitschek, E. J.; Secor, D. H.

2005-07-01

421

Microsatellite length variation in candidate genes correlates with habitat in the gilthead sea bream Sparus aurata.  

PubMed

The genetic basis and evolutionary implications of local adaptation in high gene flow marine organisms are still poorly understood. In several Mediterranean fish species, alternative migration patterns exist between individuals entering coastal lagoons that offer favourable conditions for growth and those staying in the sea where environmental conditions are less subject to rapid and stressful change. Whether these coexisting strategies are phenotypically plastic or include a role for local adaptation through differential survival needs to be determined. Here, we explore the genetic basis of alternate habitat use in western Mediterranean populations of the gilthead sea bream (Sparus aurata). Samples from lagoonal and open-sea habitats were typed for three candidate gene microsatellite loci, seven anonymous microsatellites and 44 amplified fragment length polymorphism markers to test for genotype-environment associations. While anonymous markers globally indicated high levels of gene flow across geographic locations and habitats, non-neutral differentiation patterns correlated with habitat type were found at two candidate microsatellite loci located in the promoter region of the growth hormone and prolactin genes. Further analysis of these two genes revealed that a mechanism based on habitat choice alone could not explain the distribution of genotype frequencies at a regional scale, thus implying a role for differential survival between habitats. We also found an association between allele size and habitat type, which, in the light of previous studies, suggests that polymorphisms in the proximal promoter region could influence gene expression by modulating transcription factor binding, thus providing a potential explanatory link between genotype and growth phenotype in nature. PMID:23061421

Chaoui, Lamya; Gagnaire, Pierre-Alexandre; Guinand, Bruno; Quignard, Jean-Pierre; Tsigenopoulos, Costas; Kara, M Hichem; Bonhomme, François

2012-10-12

422

An appraisal of the fitness consequences of forest disturbance for wildlife using habitat selection theory.  

PubMed

Isodar theory can help to unveil the fitness consequences of habitat disturbance for wildlife through an evaluation of adaptive habitat selection using patterns of animal abundance in adjacent habitats. By incorporating measures of disturbance intensity or variations in resource availability into fitness-density functions, we can evaluate the functional form of isodars expected under different disturbance-fitness relationships. Using this framework, we investigated how a gradient of forest harvesting disturbance and differences in resource availability influenced habitat quality for snowshoe hares (Lepus americanus) and red-backed voles (Myodes gapperi) using pairs of logged and uncut boreal forest. Isodars for both species had positive intercepts, indicating reductions to maximum potential fitness in logged stands. Habitat selection by hares depended on both conspecific density and differences in canopy cover between harvested and uncut stands. Fitness-density curves for hares in logged stands were predicted to shift from diverging to converging with those in uncut forest across a gradient of high to low disturbance intensity. Selection for uncut forests thus became less pronounced with increasing population size at low levels of logging disturbance. Voles responded to differences in moss cover between habitats which reflected moisture availability. Lower moss cover in harvested stands either reduced maximum potential fitness or increased the relative rate of decline in fitness with density. Differences in vole densities between harvested and uncut stands were predicted, however, to diminish as populations increased. Our findings underscore the importance of accounting for density-dependent behaviors when evaluating how changing habitat conditions influence animal distribution. PMID:20658153

Hodson, James; Fortin, Daniel; Leblanc, Mélanie-Louise; Bélanger, Louis

2010-07-24

423

Benthic macrofauna habitat associations in Willapa Bay, Washington, USA  

NASA Astrophysics Data System (ADS)

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

Ferraro, Steven P.; Cole, Faith A.

2007-02-01

424

Habitat workshops: Knowledge, care and practice  

NASA Astrophysics Data System (ADS)

One commonly expressed goal of environmental education (EE) is to create positive attitudes. The dominant approaches emphasize factual information, assuming that attitudes will result, but results are mixed. I investigate conceptions of attitude, the psychology of attitude and how attitudes are learned. I also examine recent scholarship describing learning and teaching, since EE literature does not draw upon many of these ideas. I consider applications of these two perspectives to public schools while working within mainstream (Tbilisi) EE guidelines. It turns out to be important to identify specific, concrete objects and behaviours as targets for attitudes. "Environment" is general and abstract. Strongly related to attitudes, but little discussed, is the self-concept, which influences what one thinks, feels and does. I found that goals about attitudes can be more precisely phrased in terms of care, a positive concern for or interest in an object. I conclude that affective EE goals can be achieved through thoughtful and self-reflective care about local habitats and the species and individuals that inhabit them. Psychologists note that people are better able to manage their knowledge, to transfer ideas to new contexts, and to identify and solve problems if they learn within a group participating in realistic projects. Such interactions also integrate knowledge, skills and attitudes related to the group's work. Building on the Community of Learners model of teaching, I offer a framework for EE curriculum called Habitat Workshops. Its goals are knowledge of, care about and problem solving practices with habitats. Habitat Workshops engage classroom communities in the design and creation of local habitats within a group narrative of care and understanding. They involve both school subject knowledge as well as habitat-specific problems and responses that reflect real-world environmental issues. Habitat Workshops can be simple or progressively more complex. I provide an example of an elementary school Workshop creating habitats for Painted Lady caterpillars and butterflies. Habitat Workshops embody one conception of EE and can be integrated with other approaches. They are particularly appropriate for a student's first EE experience.

Brown, Glenn Russell

425

Habitat use and movement of the endangered Arroyo Toad (Anaxyrus californicus) in coastal southern California  

USGS Publications Warehouse

Information on the habitat use and movement patterns of Arroyo Toads (Anaxyrus californicus) is limited. The temporal and spatial characteristics of terrestrial habitat use, especially as it relates to upland use in coastal areas of the species' range, are poorly understood. We present analyses of radiotelemetry data from 40 individual adult toads tracked at a single site in coastal southern California from March through November of 2004. We quantify adult Arroyo Toad habitat use and movements and interpret results in the context of their life history. We show concentrated activity by both male and female toads along stream terraces during and after breeding, and, although our fall sample size is low, the continued presence of adult toads in the floodplain through the late fall. Adult toads used open sandy flats with sparse vegetation. Home-range size and movement frequency varied as a function of body mass. Observed spatial patterns of movement and habitat use both during and outside of the breeding period as well as available climatological data suggest that overwintering of toads in floodplain habitats of near-coastal areas of southern California may be more common than previously considered. If adult toads are not migrating out of the floodplain at the close of the breeding season but instead overwinter on stream terraces in near-coastal areas, then current management practices that assume toad absence from floodplain habitats may be leaving adult toads over-wintering on stream terraces vulnerable to human disturbance during a time of year when Arroyo Toad mortality is potentially highest. ?? 2011 Society for the Study of Amphibians and Reptiles.

Mitrovich, M. J.; Gallegos, E. A.; Lyren, L. M.; Lovich, R. E.; Fisher, R. N.

2011-01-01

426

An index of reservoir habitat impairment  

USGS Publications Warehouse

Fish habitat impairment resulting from natural and anthropogenic watershed and in-lake processes has in many cases reduced the ability of reservoirs to sustain native fish assemblages and fisheries quality. Rehabilitation of impaired reservoirs is hindered by the lack of a method suitable for scoring impairment status. To address this limitation, an index of reservoir habitat impairment (IRHI) was developed by merging 14 metrics descriptive of common impairment sources, with each metric scored from 0 (no impairment) to 5 (high impairment) by fisheries scientists with local knowledge. With a plausible range of 5 to 25, distribution of the IRHI scores ranged from 5 to 23 over 482 randomly selected reservoirs dispersed throughout the USA. The IRHI reflected five impairment factors including siltation, structural habitat, eutrophication, water regime, and aquatic plants. The factors were weakly related to key reservoir characteristics including reservoir area, depth, age, and usetype, suggesting that common reservoir descriptors are poor predictors of fish habitat impairment. The IRHI is rapid and inexpensive to calculate, provides an easily understood measure of the overall habitat impairment, allows comparison of reservoirs and therefore prioritization of restoration activities, and may be used to track restoration progress. The major limitation of the IRHI is its reliance on unstandardized professional judgment rather than standardized empirical measurements. ?? 2010 US Government.

Miranda, L. E.; Hunt, K. M.

2011-01-01

427

Habitat fragmentation resulting in overgrazing by herbivores.  

PubMed

Habitat fragmentation sometimes results in outbreaks of herbivorous insect and causes an enormous loss of primary production. It is hypothesized that the driving force behind such herbivore outbreaks is disruption of natural enemy attack that releases herbivores from top-down control. To test this hypothesis I studied how trophic community structure changes along a gradient of habitat fragmentation level using spatially implicit and explicit models of a tri-trophic (plant, herbivore and natural enemy) food chain. While in spatially implicit model number of trophic levels gradually decreases with increasing fragmentation, in spatially explicit model a relatively low level of habitat fragmentation leads to overgrazing by herbivore to result in extinction of the plant population followed by a total system collapse. This provides a theoretical support to the hypothesis that habitat fragmentation can lead to overgrazing by herbivores and suggests a central role of spatial structure in the influence of habitat fragmentation on trophic communities. Further, the spatially explicit model shows (i) that the total system collapse by the overgrazing can occur only if herbivore colonization rate is high; (ii) that with increasing natural enemy colonization rate, the fragmentation level that leads to the system collapse becomes higher, and the frequency of the collapse is lowered. PMID:14615203

Kondoh, Michio

2003-12-21

428

Local abundance patterns of noctuid moths in olive orchards: life-history traits, distribution type and habitat interactions.  

PubMed

Local species abundance is related to range size, habitat characteristics, distribution type, body size, and life-history variables. In general, habitat generalists and polyphagous species are more abundant in broad geographical areas. Underlying this, local abundance may be explained from the interactions between life-history traits, chorological pattern, and the local habitat characteristics. The relationship within taxa between life-history traits, distribution area, habitat characteristics, and local abundance of the noctuid moth (Lepidoptera: Noctuidae) assemblage in an olive orchard, one of the most important agro-ecosystems in the Mediterranean basin, was analyzed. A total of 66 species were detected over three years of year-round weekly samplings using the light-trap method. The life-history traits examined and the distribution type were found to be related to the habitat-species association, but none of the biological strategies defined from the association to the different habitats were linked with abundance. In contrast to general patterns, dispersal ability and number of generations per year explained differences in abundance. The relationships were positive, with opportunistic taxa that have high mobility and several generations being locally more abundant. In addition, when the effect of migrant species was removed, the distribution type explained abundance differences, with Mediterranean taxa (whose baricenter is closer to the studied area) being more abundant. PMID:21529251

Pérez-Guerrero, Sergio; Redondo, Alberto José; Yela, José Luis

2011-01-01

429

North American Brant: Effects of changes in habitat and climate on population dynamics  

USGS Publications Warehouse

We describe the importance of key habitats used by four nesting populations of nearctic brant (Branta bernicla) and discuss the potential relationship between changes in these habitats and population dynamics of brant. Nearctic brant, in contrast to most geese, rely on marine habitats and native intertidal plants during the non-breeding season, particularly the seagrass, Zostera, and the macroalgae, Ulva. Atlantic and Eastern High Arctic brant have experienced the greatest degradation of their winter habitats (northeastern United States and Ireland, respectively) and have also shown the most plasticity in feeding behavior. Black and Western High Arctic brant of the Pacific Flyway are the most dependent on Zostera, and are undergoing a shift in winter distribution that is likely related to climate change and its associated effects on Zostera dynamics. Variation in breeding propensity of Black Brant associated with winter location and climate strongly suggests that food abundance on the wintering grounds directly affects reproductive performance in these geese. In summer, salt marshes, especially those containing Carex and Puccinellia, are key habitats for raising young, while lake shorelines with fine freshwater grasses and sedges are important for molting birds. Availability and abundance of salt marshes has a direct effect on growth and recruitment of goslings and ultimately, plays an important role in regulating size of local brant populations. ?? 2005 Blackwell Publishing Ltd.

Ward, D. H.; Reed, A.; Sedinger, J. S.; BLack, J. M.; Derksen, D. V.; Castelli, P. M.

2005-01-01

430

Distribution, abundance, and habitat affinities of the Coastal Plain Swamp Sparrow  

USGS Publications Warehouse

We examined the distribution and abundance of the Coastal Plain Swamp Sparrow (Melospiza georgiana nigrescens) at previously occupied sites and points within potential habitat. We found Swamp Sparrows throughout their formerly documented range except in southern Chesapeake Bay. Swamp Sparrows were most common in the Mullica River region of New Jersey where we detected individuals at 78% of systematically chosen points with a mean count of 4.1 birds/point. The percentages of points with positive detections in. the regions of Delaware River (39%), eastern Delaware Bay (23%), western Delaware Bay (34%), and Tuckahoe River (31%) were lower. The mean count of birds/point was between 0.4 and 0.6 in these regions. A higher resolution Poisson model of relative abundance suggested that the greatest concentrations of Swamp Sparrows occurred not only in the Mullica River area but also along northwestern Delaware Bay. Regression analysis of Swamp Sparrow counts and habitat features identified shrubs (Iva frutescens and Baccharis halimifolia) as a key habitat component. By applying density estimates generated by DISTANCE (Thomas et al. 1998) to the approximate area of potential shrub habitat along Delaware Bay, we estimated that the core population of Coastal Plain Swamp Sparrows was less than 28,000 pairs. We recommend that the Coastal Plain Swamp Sparrow be listed as a subspecies of concern by state and local governments because of its relatively small population size, restricted distribution in the mid-Atlantic region, and narrow habitat requirements.

Beadell, J.; Greenberg, R.; Droege, S.; Royle, J.A.

2003-01-01

431

Wildlife food habits and habitat use on revegetated strip mine land in Alaska  

SciTech Connect

Food habits and habitat utilization of wildlife species on revegetated strip mine spoils in interior Alaska were studied from 1980 through 1982. Current reclamation techniques were beneficial for tundra voles, short-eared owls and marsh hawks. Caribou, Dall sheep, red fox, coyote, wolf, arctic ground squirrel, waterfoul, and various raptorial birds derived partial benefit from the reclaimed areas. The seeded grasses functioned as minor items in the diets of herbivores while reclaimed sites served as hunting areas for the various carnivores and raptors. Moose, showshoe hare, red-backed voles, willow ptarmigan and most nongame birds were adversely impacted by the reclaimed areas. Woody vegetation and its associated attributes such as cover and food were the essential habitat component missing from the reclaimed areas. Strip mining and reclamation procedures currently practiced in interior Alaska result in grassland interspersed throughout the natural habitat. The availability of undisturbed habitat adjacent to small sized, seeded areas, has made it possible for wildlife to take advantage of the reclaimed sites and still have sufficient amount of natural food and cover available with which to meet the nutritional and habitat needs of the animal. The detrimental effects of current reclamation procedures increase as the amounts of land disturbed by mining become very large.

Elliott, C.L.

1984-01-01

432

Remotely sensed habitat diversity predicts butterfly species richness and community similarity in Canada  

PubMed Central

Although there is no shortage of potential explanations for the large-scale patterns of biological diversity, the hypothesis that energy-related factors are the primary determinants is perhaps most extensively supported, especially in cold-temperate regions. By using unusually high-resolution biodiversity and environmental data that have not previously been available, we demonstrate that habitat heterogeneity, as measured by remotely sensed land cover variation, explains Canadian butterfly richness better than any energy-related variable we measured across spatial scales. Although species-richness predictability declines with progressively smaller quadrat sizes, as expected, we demonstrate that most variability (>90%) in butterfly richness may be explained by habitat heterogeneity with secondary contributions from climatic energy. We also find that patterns of community similarity across Canada are strongly related to patterns of habitat composition but not to differences in energy-related factors. Energy should still be considered significant but its main role may be through its effects on within-habitat diversity and perhaps, indirectly, on the sorts of habitats that may be found in a region. Effects of sampling intensity and spatial autocorrelation do not alter our findings.

Kerr, Jeremy T.; Southwood, T. R. E.; Cihlar, Josef

2001-01-01

433

Remotely sensed habitat diversity predicts butterfly species richness and community similarity in Canada.  

PubMed

Although there is no shortage of potential explanations for the large-scale patterns of biological diversity, the hypothesis that energy-related factors are the primary determinants is perhaps most extensively supported, especially in cold-temperate regions. By using unusually high-resolution biodiversity and environmental data that have not previously been available, we demonstrate that habitat heterogeneity, as measured by remotely sensed land cover variation, explains Canadian butterfly richness better than any energy-related variable we measured across spatial scales. Although species-richness predictability declines with progressively smaller quadrat sizes, as expected, we demonstrate that most variability (>90%) in butterfly richness may be explained by habitat heterogeneity with secondary contributions from climatic energy. We also find that patterns of community similarity across Canada are strongly related to patterns of habitat composition but not to differences in energy-related factors. Energy should still be considered significant but its main role may be through its effects on within-habitat diversity and perhaps, indirectly, on the sorts of habitats that may be found in a region. Effects of sampling intensity and spatial autocorrelation do not alter our findings. PMID:11553792

Kerr, J T; Southwood, T R; Cihlar, J

2001-09-11

434

Ecological risk of aquatic habitat degradation  

SciTech Connect

Habitat degradation constitutes a significant risk to the biotic integrity of freshwater ecosystems, especially streams and rivers. The degradation can result from any action that alters the physical or chemical attributes of a stream, thus reducing its utilization by biota. Activities that are known to degrade aquatic habitats include dredging and filling of wetlands; stream channel realignment; destruction of riparian vegetation; modifications in flow regimes, including both temporal shifts and spatial changes; and siltation caused by soil erosion and runoff. The ecological consequences of these activities occur on varying spatial scales, from highly localized effects, such as small stream channelization projects to control residential flooding, to river basin-level effects from the construction of large dams for hydropower generation or for water storage in support of agricultural development. By reducing habitat quality and availability, all of these activities can impact biotic populations that inhabit freshwater environments. 6 refs.

Loar, J.M.

1991-01-01

435

Landscape habitat diversity: An information theoretic measure  

SciTech Connect

Biotic diversity is a topic of increasing concern, but current tools for quantifying diversity at the landscape level are inadequate. A new index is proposed. Beginning with a classified raster image of a landscape, each habitat type is assigned a value based on an ordination axis distance. The change in value from one patch to the next depends on how similar the two patches are. An information measure d{sub I} is used to evaluate deviation from uniformity of the ordination values at different scales. Different areas can be compared if habitat values are based on the same ordination scale. This new method provides a powerful tool for both displaying and calculating landscape habitat diversity.

Loehle, C. [Argonne National Lab., IL (United States); Wein, G. [Memphis State Univ., TN (United States). Dept. of Biology

1994-06-01

436

Architectural considerations for lunar long duration habitat  

NASA Astrophysics Data System (ADS)

The future of space exploration science and technology is expected to move toward long duration missions. During this long duration missions the most important factor to success will be the habitation system, the place that crew will live and work. The broad range of future space exploration, new advances in technology and increasing demand for space travel and space tourism will create great opportunities for architects to use their special abilities and skills in the realm of space. The lunar habitat is defined as a multidisciplinary task and cannot be considered an independent project from the main module. Therefore, habitability will become the most important aspect of future human exploration. A successful design strategy should integrate architecture, structure and other disciplines and should bring in elements such as psychological and physiological factors, human interfaces, and privacy. The current research provides "Habitat Architectural Design System (HADS)" in order to evaluate lunar habitat concepts based on habitability, functional optimization, and human factors. HADS helps to promote parametric studied and evaluation of habitat concepts. It will provide a guideline dependent upon mission objectives to standardize architectural needs within the engineering applications and scientific demands. The significance of this research is the process of developing lunar habitat concepts using an architectural system to evaluate the quality of each concept via habitability aspects. This process can be employed during the early stage of design development and is flexible enough to be adjusted by different parameters according to the objectives of lunar mission, limitations, and cost. It also emphasizes the importance of architecture involvement in space projects, especially habitats.

Bahrami, Payam

437

Omicron space habitat—research stage II  

NASA Astrophysics Data System (ADS)

The design presented in this paper is in response to the revolution in private space activities, the increasing public interest in commercial flights to space and the utilization of structures such as space hotels or private orbital habitats. The baseline for the Omicron design concept is the Russian Salyut derived space station module. Salyut was the first space station to orbit the Earth. Its unique design and technical features were what made the development of space stations Salyut 1-7, MIR and the International Space Station (ISS) Zwezda service module possible. Due to its versatility and the reliable operating launch vehicle Proton, this space module series has the potential to be adapted for space hotel development. This paper proposes a conceptual design of the space habitat called Omicron, with particular focus on interior design for the microgravity environment. The Omicron concepts address the needs of space tourism with a strong emphasis on the safety and comfort of the spaceflight participants. The Omicron habitat supports three inhabitants in nominal conditions (e.g., two passengers and one astronaut). The habitat provides a flexible interior, facilities and spaces dynamically transforming in order to accommodate various types of activities, which will be performed in an organically formed interior supporting spatial orientation and movement in microgravity. The future development potential of Omicron is also considered. The baseline version is composed solely of one rigid module with an inverted cupola for observations. An alternative version offers more space using an inflatable structure. Finally, a combination of multiple Omicron modules enables the creation of a larger orbital habitat. The Omicron's subsystems support a few days visit by trained passengers. The transport to the habitat would be provided e.g., by the Soyuz TMA spacecraft carried by the Soyuz launch vehicle in the early stage of Omicron's development, before a fully reusable spacecraft would be available.

Doule, Ond?ej; Šálený, Vratislav; Hérin, Benoît; Rousek, Tomáš

2012-01-01

438

Habitat Suitability Index Models: Coastal Stocks of Striped Bass  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop estuarine habitat models for coastal stocks of striped bass (Morone saxatilis). Models for five life stages are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1 (optimally suitable habitat) for estuarine areas of the continental United States. Habitat suitability indexes are designed for use with the habitat evaluation procedures developed by the U.S. Fish and Wildlife Service. Guidelines for coastal striped bass model applications and techniques for estimating model variable are described.

Bain, Mark B.; Bain, Jane L.

1982-01-01

439

Environmental mycobacteria from alpine and subalpine habitats.  

PubMed

Abstract Mycobacteria were isolated from a variety of materials such as soil, peat, humus, tufa, sphagnum, and wood, collected in alpine and subalpine habitats. Mycobacteria, including Mycobacterium kansasii, Mycobacterium malmoense, Mycobacterium szulgai, Mycobacterium gordonae, Mycobacterium terrae, Mycobacterium chelonae, and Mycobacterium fortuitum were recovered from 69 of 81 (85%) samples. All of the isolates were recovered on medium incubated at 20 and 30 degrees C. None were recovered if the medium was incubated at 37 degrees C. The isolation of mycobacteria confirms the presence of these opportunistic pathogens in alpine habitats. PMID:19712284

Thorel, Marie-Francoise; Falkinham, Joseph O; Moreau, R G

2004-09-01

440

Vesicle sizing  

PubMed Central

A procedure is described which optimizes nonnegative least squares and exponential sampling fitting methods for analysis of dynamic light scattering (DLS) data from aqueous suspensions of vesicle/liposome systems. This approach utilizes a Rayleigh-Gans-Debye form factor for a coated sphere and yields number distributions which can be compared directly to distributions obtained by freeze-fracture electron microscopy (EM). Excellent agreement between the DLS and EM results are obtained for vesicle size distributions in the 100-200-nm range.

Hallett, F. R.; Watton, J.; Krygsman, P.

1991-01-01

441

Size Matters  

PubMed Central

We tallied the number of possible mutant amino acids in proteins thought to be inactivated early in tumorigenesis and in proteins thought to be inactivated late in tumorigenesis, respectively. Proteins thought to be inactivated early in tumorigenesis, on average, have a greater number of alternative, mutant possibilities, which raises the possibility that the sequential order of mutations associated with cancer development reflects the random chance, throughout life, of a mutagen inactivating a larger versus a smaller target. The hypothesis that the temporal order of genetic changes in cancer reflects mutagen target sizes leads to novel considerations of 1) the mechanisms of the acquisition of cancer hallmarks and 2) cancer screening strategies.

Long, Kimberly; Abuelenen, Toaa; Pava, Libia; Bastille, Maya

2011-01-01

442

Information to support to monitoring and habitat restoration on Ash Meadows National Wildlife Refuge  

USGS Publications Warehouse

The Ash Meadows National Wildlife Refuge staff focuses on improving habitat for the highest incidence of endemic species for an area of its size in the continental United States. Attempts are being made to restore habitat to some semblance of its pre-anthropogenic undisturbed condition, and to provide habitat conditions to which native plant and animal species have evolved. Unfortunately, restoring the Ash Meadows’ Oases to its pre-anthropogenic undisturbed condition is almost impossible. First, there are constraints on water manipulation because there are private holdings within the refuge boundary; second, there has been at least one species extinction—the Ash Meadows pool fish (Empetrichthys merriami). It is also quite possible that thermal endemic invertebrate species were lost before ever being described. Perhaps the primary obstacle to restoring Ash Meadows to its pre-anthropogenic undisturbed conditions is the presence of invasive species. However, invasive species, such as red swamp crayfish (Procambarus clarki) and western mosquitofish (Gambusia affinis), are a primary driving force in restoring Ash Meadows’ spring systems, because under certain habitat conditions they can all but replace native species. Returning Ash Meadows’ physical landscape to some semblance of its pre-anthropogenic undisturbed condition through natural processes may take decades. Meanwhile, the natural dissolution of concrete and earthen irrigation channels threatens to allow cattail marshes to flourish instead of spring-brooks immediately downstream of spring discharge. This successional stage favors non-native crayfish and mosquitofish over the native Amargosa pupfish (Cyprinodon nevadensis). Thus, restoration is needed to control non-natives and to promote native species, and without such intervention the probability of native fish reduction or loss, is anticipated. The four studies in this report are intended to provide information for restoring native fish habitat and for monitoring native fish populations in relation to restoration efforts on the Ash Meadows National Wildlife Refuge. There are no precise records on conditions of each of the spring systems prior to anthropogenic alteration; however, fostering conditions that favor native over non-natives will be key to habitat restoration. Information regarding native species carbon source is needed to create habitat that favors native species, thus habitat restoration fostering food stuff consumed by native species should be considered in restoration efforts. In compiling data for the first part of this report, we tracked carbon source for native and non-native species at four stations along the Jackrabbit Spring system. Thus, we were able to contrast carbon source in warm- and cool-water habitats. Habitat in Jackrabbit Spring was improved for native fishes in 2007. The second paper in this report focuses on native fish populations in Jackrabbit Spring system pre- and post-restoration. Much of the Ash Meadows Oases is marsh habitat where non-native red swamp crayfish and western mosquitofish are often abundant, to the detriment of non-natives. Because marsh habitat is broadly represented in the Ash Meadows landscape, establishing marsh habitat most conducive to the native fishes is important to the restoration effort, and the third paper addresses marsh habitat type with the relative abundance of fishes and crayfish. There are previous years of monitoring Ash Meadows’ native fish populations, but not all monitoring occurred at the same time of year. Desert-fish populations sometimes undergo seasonal fluctuation, so it might not be valid to compare population trends using difference seasons. For report four, we tracked a closed population of Amargosa pupfish (Cyprinodon nevadensis) year round to track seasonal trends. Knowledge of seasonal trends is important in tracking changes of populations pre- and post-restoration.

Scoppettone, G. Gary

2013-01-01

443

Assessment of fish assemblages in coastal lagoon habitats: Effect of sampling method  

NASA Astrophysics Data System (ADS)

The structure of fish assemblages accounted for by different sampling methods (namely fyke net, seine nets, visual census) applied to vegetated and unvegetated lagoon habitats was investigated in terms of species composition, functional groups (ecological and trophic guilds), and fish size distribution. Significant differences were detected among methods, even among similar ones (seine nets). Visual census and fyke net detected more easily pelagic species, allowing the sampling of larger fish, whereas seine nets targeted more efficiently benthic-demersal species, with a dominance of 2-10 cm size classes in the fish catches. Differences were detected also among habitats, reflecting the different fish assemblages associated to vegetated and unvegetated habitats in coastal lagoons and transitional waters. However a different ability of discriminating between habitat-associated fish assemblages was recorded for the sampling methods. The different selectivity and functioning of the tested sampling methods confirm the importance of considering the targeted scale at which the research is being carried out, as well as the method that will be used to assess the ecological status of lagoon fish assemblages when choosing the most appropriate sampling method. A cross-validation of fish sampling methodologies in transitional waters is necessary to cope with the mandatory of the Water Framework Directive of standardization and comparability of monitoring methods.

Franco, A.; Pérez-Ruzafa, A.; Drouineau, H.; Franzoi, P.; Koutrakis, E. T.; Lepage, M.; Verdiell-Cubedo, D.; Bouchoucha, M.; López-Capel, A.; Riccato, F.; Sapounidis, A.; Marcos, C.; Oliva-Paterna, F. J.; Torralva-Forero, M.; Torricelli, P.

2012-10-01

444

Home Range, habitat use and survival of coyotes in Western South Carolina.  

SciTech Connect

ABSTRACT.—Home range size, habitat use and survival of coyotes are variable throughout their range. Because coyotes have recently become established in South Carolina, we investigated their spatial distribution, habitat use and mortality on the Savannah River Site (SRS) in western South Carolina, USA. Annual survival for adult coyotes on the SRS was 0.658. Off-site trapping and shooting accounted for 60% of mortality. Home ranges averaged 30.5 km2 and 31.85 km2 by the 95% minimum convex polygon and 95% fixed kernel methods, respectively. We detected no difference in home ranges size between males and females. Intraspecific home range overlap averaged 22.4%, excluding mated pair interactions, with 87.5% of coyotes sharing their home range with one or more individuals. Coyotes selected home ranges containing higher proportions of early successional habitat than was available on the landscape. Core areas likewise contained a greater proportion of early successional habitat than available in the animal’s home range.

Schrecengost, Joshua, D.; Kilgo, John, C.; Ray, H., Scott; Miller, Karl, V.

2009-01-01

445

Plant reproductive susceptibility to habitat fragmentation: review and synthesis through a meta-analysis.  

PubMed

The loss and fragmentation of natural habitats by human activities are pervasive phenomena in terrestrial ecosystems across the Earth and the main driving forces behind current biodiversity loss. Animal-mediated pollination is a key process for the sexual reproduction of most extant flowering plants, and the one most consistently studied in the context of habitat fragmentation. By means of a meta-analysis we quantitatively reviewed the results from independent fragmentation studies throughout the last two decades, with the aim of testing whether pollination and reproduction of plant species may be differentially susceptible to habitat fragmentation depending on certain reproductive traits that typify the relationship with and the degree of dependence on their pollinators. We found an overall large and negative effect of fragmentation on pollination and on plant reproduction. The compatibility system of plants, which reflects the degree of dependence on pollinator mutualism, was the only reproductive trait that explained the differences among the species' effect sizes. Furthermore, a highly significant correlation between the effect sizes of fragmentation on pollination and reproductive success suggests that the most proximate cause of reproductive impairment in fragmented habitats may be pollination limitation. We discuss the conservation implications of these findings and give some suggestions for future research into this area. PMID:16913941

Aguilar, Ramiro; Ashworth, Lorena; Galetto, Leonardo; Aizen, Marcelo Adrián

2006-08-01

446

Habitat Quality and Geometry Affect Patch Occupancy of Two Orthopteran Species  

PubMed Central

Impacts of habitat loss and fragmentation on distribution and population size of many taxa are well established. In contrast, less is known about the role of within-patch habitat quality for the spatial dynamics of species, even though within-patch habitat quality may substantially influence the dynamics of population networks. We studied occurrence patterns of two Orthopteran species in relation to size, isolation and quality of habitat patches in an intensively managed agricultural landscape (16.65 km2) in the Swiss lowland. Occurrence of field crickets (Gryllus campestris) was positively related to patch size and negatively to the distance to the nearest occupied patch, two measures of patch geometry. Moreover, field crickets were more likely to occur in extensively managed meadows, meadows used at low intensity and meadows dominated by Poa pratensis, three measures of patch quality. Occurrence of the large gold grasshopper (Chrysochraon dispar) was negatively related to two measures of patch geometry, distance to the nearest occupied patch and perimeter index (ratio of perimeter length to patch area). Further, large gold grasshoppers were more likely to occupy patches close to water and patches with vegetation left uncut over winter, two measures of patch quality. Finally, examination of patch occupancy dynamics of field crickets revealed that patches colonized in 2009 and patches occupied in both 2005 and 2009 were larger, better connected and of other quality than patches remaining unoccupied and patches from which the species disappeared. The strong relationships between Orthopteran occurrence and aspects of patch geometry found in this study support the “area-and-isolation paradigm”. Additionally, our study reveals the importance of patch quality for occurrence patterns of both species, and for patch occupancy dynamics in the field cricket. An increased understanding of patch occupancy patterns may be gained if inference is based on variables related to both habitat geometry and quality.

Pasinelli, Gilberto; Meichtry-Stier, Kim; Birrer, Simon; Baur, Bruno; Duss, Martin

2013-01-01