Science.gov

Sample records for quantifying habitat requirements

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

    USGS Publications Warehouse

    Donovan, T.M.; Freeman, M.; Abouelezz, H.; Royar, K.; Howard, A.; Mickey, R.

    2011-01-01

    We demonstrate how home range and habitat use analysis can inform landscape-scale conservation planning for the bobcat, Lynx rufus, in Vermont USA. From 2005 to 2008, we outfitted fourteen bobcats with GPS collars that collected spatially explicit locations from individuals every 4. h for 3-4. months. Kernel home range techniques were used to estimate home range size and boundaries, and to quantify the utilization distribution (UD), which is a spatially explicit, topographic mapping of how different areas within the home range are used. We then used GIS methods to quantify both biotic (e.g. habitat types, stream density) and abiotic (e.g. slope) resources within each bobcat's home range. Across bobcats, upper 20th UD percentiles (core areas) had 18% less agriculture, 42% less development, 26% more bobcat habitat (shrub, deciduous, coniferous forest, and wetland cover types), and 33% lower road density than lower UD percentiles (UD valleys). For each bobcat, we used Akaike's Information Criterion (AIC) to evaluate and compare 24 alternative Resource Utilization Functions (hypotheses) that could explain the topology of the individual's UD. A model-averaged population-level Resource Utilization Function suggested positive responses to shrub, deciduous, coniferous forest, and wetland cover types within 1. km of a location, and negative responses to roads and mixed forest cover types within 1. km of a location. Applying this model-averaged function to each pixel in the study area revealed habitat suitability for bobcats across the entire study area, with suitability scores ranging between -1.69 and 1.44, where higher values were assumed to represent higher quality habitat. The southern Champlain Valley, which contained ample wetland and shrub habitat, was a concentrated area of highly suitable habitat, while areas at higher elevation areas were less suitable. Female bobcat home ranges, on average, had an average habitat suitability score of near 0, indicating that home

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

    USGS Publications Warehouse

    Donovan, Therese; Freeman, Mark; Abouelezz, Hanem; Royar, K.; Howard, Alan D.; Mickey, R.

    2011-01-01

    We demonstrate how home range and habitat use analysis can inform landscape-scale conservation planning for the bobcat, Lynx rufus, in Vermont USA. From 2005 to 2008, we outfitted fourteen bobcats with GPS collars that collected spatially explicit locations from individuals every 4 h for 3–4 months. Kernel home range techniques were used to estimate home range size and boundaries, and to quantify the utilization distribution (UD), which is a spatially explicit, topographic mapping of how different areas within the home range are used. We then used GIS methods to quantify both biotic (e.g. habitat types, stream density) and abiotic (e.g. slope) resources within each bobcat’s home range. Across bobcats, upper 20th UD percentiles (core areas) had 18% less agriculture, 42% less development, 26% more bobcat habitat (shrub, deciduous, coniferous forest, and wetland cover types), and 33% lower road density than lower UD percentiles (UD valleys). For each bobcat, we used Akaike’s Information Criterion (AIC) to evaluate and compare 24 alternative Resource Utilization Functions (hypotheses) that could explain the topology of the individual’s UD. A model-averaged population-level Resource Utilization Function suggested positive responses to shrub, deciduous, coniferous forest, and wetland cover types within 1 km of a location, and negative responses to roads and mixed forest cover types within 1 km of a location. Applying this model-averaged function to each pixel in the study area revealed habitat suitability for bobcats across the entire study area, with suitability scores ranging between −1.69 and 1.44, where higher values were assumed to represent higher quality habitat. The southern Champlain Valley, which contained ample wetland and shrub habitat, was a concentrated area of highly suitable habitat, while areas at higher elevation areas were less suitable. Female bobcat home ranges, on average, had an average habitat suitability score of near 0, indicating

  3. Quantifying consistent individual differences in habitat selection.

    PubMed

    Leclerc, Martin; Vander Wal, Eric; Zedrosser, Andreas; Swenson, Jon E; Kindberg, Jonas; Pelletier, Fanie

    2016-03-01

    Habitat selection is a fundamental behaviour that links individuals to the resources required for survival and reproduction. Although natural selection acts on an individual's phenotype, research on habitat selection often pools inter-individual patterns to provide inferences on the population scale. Here, we expanded a traditional approach of quantifying habitat selection at the individual level to explore the potential for consistent individual differences of habitat selection. We used random coefficients in resource selection functions (RSFs) and repeatability estimates to test for variability in habitat selection. We applied our method to a detailed dataset of GPS relocations of brown bears (Ursus arctos) taken over a period of 6 years, and assessed whether they displayed repeatable individual differences in habitat selection toward two habitat types: bogs and recent timber-harvest cut blocks. In our analyses, we controlled for the availability of habitat, i.e. the functional response in habitat selection. Repeatability estimates of habitat selection toward bogs and cut blocks were 0.304 and 0.420, respectively. Therefore, 30.4 and 42.0 % of the population-scale habitat selection variability for bogs and cut blocks, respectively, was due to differences among individuals, suggesting that consistent individual variation in habitat selection exists in brown bears. Using simulations, we posit that repeatability values of habitat selection are not related to the value and significance of β estimates in RSFs. Although individual differences in habitat selection could be the results of non-exclusive factors, our results illustrate the evolutionary potential of habitat selection.

  4. Quantifying consistent individual differences in habitat selection.

    PubMed

    Leclerc, Martin; Vander Wal, Eric; Zedrosser, Andreas; Swenson, Jon E; Kindberg, Jonas; Pelletier, Fanie

    2016-03-01

    Habitat selection is a fundamental behaviour that links individuals to the resources required for survival and reproduction. Although natural selection acts on an individual's phenotype, research on habitat selection often pools inter-individual patterns to provide inferences on the population scale. Here, we expanded a traditional approach of quantifying habitat selection at the individual level to explore the potential for consistent individual differences of habitat selection. We used random coefficients in resource selection functions (RSFs) and repeatability estimates to test for variability in habitat selection. We applied our method to a detailed dataset of GPS relocations of brown bears (Ursus arctos) taken over a period of 6 years, and assessed whether they displayed repeatable individual differences in habitat selection toward two habitat types: bogs and recent timber-harvest cut blocks. In our analyses, we controlled for the availability of habitat, i.e. the functional response in habitat selection. Repeatability estimates of habitat selection toward bogs and cut blocks were 0.304 and 0.420, respectively. Therefore, 30.4 and 42.0 % of the population-scale habitat selection variability for bogs and cut blocks, respectively, was due to differences among individuals, suggesting that consistent individual variation in habitat selection exists in brown bears. Using simulations, we posit that repeatability values of habitat selection are not related to the value and significance of β estimates in RSFs. Although individual differences in habitat selection could be the results of non-exclusive factors, our results illustrate the evolutionary potential of habitat selection. PMID:26597548

  5. Quantifying spatial habitat loss from hydrocarbon development through assessing habitat selection patterns of mule deer.

    PubMed

    Northrup, Joseph M; Anderson, Charles R; Wittemyer, George

    2015-11-01

    Extraction of oil and natural gas (hydrocarbons) from shale is increasing rapidly in North America, with documented impacts to native species and ecosystems. With shale oil and gas resources on nearly every continent, this development is set to become a major driver of global land-use change. It is increasingly critical to quantify spatial habitat loss driven by this development to implement effective mitigation strategies and develop habitat offsets. Habitat selection is a fundamental ecological process, influencing both individual fitness and population-level distribution on the landscape. Examinations of habitat selection provide a natural means for understanding spatial impacts. We examined the impact of natural gas development on habitat selection patterns of mule deer on their winter range in Colorado. We fit resource selection functions in a Bayesian hierarchical framework, with habitat availability defined using a movement-based modeling approach. Energy development drove considerable alterations to deer habitat selection patterns, with the most substantial impacts manifested as avoidance of well pads with active drilling to a distance of at least 800 m. Deer displayed more nuanced responses to other infrastructure, avoiding pads with active production and roads to a greater degree during the day than night. In aggregate, these responses equate to alteration of behavior by human development in over 50% of the critical winter range in our study area during the day and over 25% at night. Compared to other regions, the topographic and vegetative diversity in the study area appear to provide refugia that allow deer to behaviorally mediate some of the impacts of development. This study, and the methods we employed, provides a template for quantifying spatial take by industrial activities in natural areas and the results offer guidance for policy makers, mangers, and industry when attempting to mitigate habitat loss due to energy development. PMID:26264447

  6. Quantifying spatial habitat loss from hydrocarbon development through assessing habitat selection patterns of mule deer.

    PubMed

    Northrup, Joseph M; Anderson, Charles R; Wittemyer, George

    2015-11-01

    Extraction of oil and natural gas (hydrocarbons) from shale is increasing rapidly in North America, with documented impacts to native species and ecosystems. With shale oil and gas resources on nearly every continent, this development is set to become a major driver of global land-use change. It is increasingly critical to quantify spatial habitat loss driven by this development to implement effective mitigation strategies and develop habitat offsets. Habitat selection is a fundamental ecological process, influencing both individual fitness and population-level distribution on the landscape. Examinations of habitat selection provide a natural means for understanding spatial impacts. We examined the impact of natural gas development on habitat selection patterns of mule deer on their winter range in Colorado. We fit resource selection functions in a Bayesian hierarchical framework, with habitat availability defined using a movement-based modeling approach. Energy development drove considerable alterations to deer habitat selection patterns, with the most substantial impacts manifested as avoidance of well pads with active drilling to a distance of at least 800 m. Deer displayed more nuanced responses to other infrastructure, avoiding pads with active production and roads to a greater degree during the day than night. In aggregate, these responses equate to alteration of behavior by human development in over 50% of the critical winter range in our study area during the day and over 25% at night. Compared to other regions, the topographic and vegetative diversity in the study area appear to provide refugia that allow deer to behaviorally mediate some of the impacts of development. This study, and the methods we employed, provides a template for quantifying spatial take by industrial activities in natural areas and the results offer guidance for policy makers, mangers, and industry when attempting to mitigate habitat loss due to energy development.

  7. QUANTIFYING STRUCTURAL PHYSICAL HABITAT ATTRIBUTES USING LIDAR AND HYPERSPECTRAL IMAGERY

    EPA Science Inventory

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

  8. Quantifying the effect of habitat availability on species distributions.

    PubMed

    Aarts, Geert; Fieberg, John; Brasseur, Sophie; Matthiopoulos, Jason

    2013-11-01

    1. If animals moved randomly in space, the use of different habitats would be proportional to their availability. Hence, deviations from proportionality between use and availability are considered the tell-tale sign of preference. This principle forms the basis for most habitat selection and species distribution models fitted to use-availability or count data (e.g. MaxEnt and Resource Selection Functions). 2. Yet, once an essential habitat type is sufficiently abundant to meet an individual's needs, increased availability of this habitat type may lead to a decrease in the use/availability ratio. Accordingly, habitat selection functions may estimate negative coefficients when habitats are superabundant, incorrectly suggesting an apparent avoidance. Furthermore, not accounting for the effects of availability on habitat use may lead to poor predictions, particularly when applied to habitats that differ considerably from those for which data have been collected. 3. Using simulations, we show that habitat use varies non-linearly with habitat availability, even when individuals follow simple movement rules to acquire food and avoid risk. The results show that the impact of availability strongly depends on the type of habitat (e.g. whether it is essential or substitutable) and how it interacts with the distribution and availability of other habitats. 4. We demonstrate the utility of a variety of existing and new methods that enable the influence of habitat availability to be explicitly estimated. Models that allow for non-linear effects (using b-spline smoothers) and interactions between environmental covariates defining habitats and measures of their availability were best able to capture simulated patterns of habitat use across a range of environments. 5. An appealing aspect of some of the methods we discuss is that the relative influence of availability is not defined a priori, but directly estimated by the model. This feature is likely to improve model prediction

  9. Quantifying multi-habitat support of Great Lakes fishes

    EPA Science Inventory

    Recent advances in trophic ecology have revealed the interconnectedness of diverse habitats in support of aquatic food webs. Understanding the degree to which different habitats support fish can be valuable for fisheries management and ecosystem protection. For example, stable is...

  10. Quantifying structural physical habitat attributes using LIDAR and hyperspectral imagery.

    PubMed

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

    2009-12-01

    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

  11. Quantifying Regional Measurement Requirements for ASCENDS

    NASA Astrophysics Data System (ADS)

    Mountain, M. E.; Eluszkiewicz, J.; Nehrkorn, T.; Hegarty, J. D.; Aschbrenner, R.; Henderson, J.; Zaccheo, S.

    2011-12-01

    Quantification of greenhouse gas fluxes at regional and local scales is required by the Kyoto protocol and potential follow-up agreements, and their accompanying implementation mechanisms (e.g., cap-and-trade schemes and treaty verification protocols). Dedicated satellite observations, such as those provided by the Greenhouse gases Observing Satellite (GOSAT), the upcoming Orbiting Carbon Observatory (OCO-2), and future active missions, particularly Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) and Advanced Space Carbon and Climate Observation of Planet Earth (A-SCOPE), are poised to play a central role in this endeavor. In order to prepare for the ASCENDS mission, we are applying the Stochastic Time-Inverted Lagrangian Transport (STILT) model driven by meteorological fields from a customized version of the Weather Research and Forecasting (WRF) model to generate surface influence functions for ASCENDS observations. These "footprints" (or adjoint) express the sensitivity of observations to surface fluxes in the upwind source regions and thus enable the computation of a posteriori flux error reductions resulting from the inclusion of satellite observations (taking into account the vertical sensitivity and error characteristics of the latter). The overarching objective of this project is the specification of the measurement requirements for the ASCENDS mission, with a focus on policy-relevant regional scales. Several features make WRF-STILT an attractive tool for regional analysis of satellite observations: 1) WRF meteorology is available at higher resolution than for global models and is thus more realistic, 2) The Lagrangian approach minimizes numerical diffusion present in Eulerian models, 3) The WRF-STILT coupling has been specifically designed to achieve good mass conservation characteristics, and 4) The receptor-oriented approach offers a relatively straightforward way to compute the adjoint of the transport model. These aspects allow

  12. Quantifying Florida Bay habitat suitability for fishes and invertebrates under climate change scenarios.

    PubMed

    Kearney, Kelly A; Butler, Mark; Glazer, Robert; Kelble, Christopher R; Serafy, Joseph E; Stabenau, Erik

    2015-04-01

    The Florida Bay ecosystem supports a number of economically important ecosystem services, including several recreational fisheries, which may be affected by changing salinity and temperature due to climate change. In this paper, we use a combination of physical models and habitat suitability index models to quantify the effects of potential climate change scenarios on a variety of juvenile fish and lobster species in Florida Bay. The climate scenarios include alterations in sea level, evaporation and precipitation rates, coastal runoff, and water temperature. We find that the changes in habitat suitability vary in both magnitude and direction across the scenarios and species, but are on average small. Only one of the seven species we investigate (Lagodon rhomboides, i.e., pinfish) sees a sizable decrease in optimal habitat under any of the scenarios. This suggests that the estuarine fauna of Florida Bay may not be as vulnerable to climate change as other components of the ecosystem, such as those in the marine/terrestrial ecotone. However, these models are relatively simplistic, looking only at single species effects of physical drivers without considering the many interspecific interactions that may play a key role in the adjustment of the ecosystem as a whole. More complex models that capture the mechanistic links between physics and biology, as well as the complex dynamics of the estuarine food web, may be necessary to further understand the potential effects of climate change on the Florida Bay ecosystem.

  13. Quantifying solar spectral irradiance in aquatic habitats for the assessment of photoenhanced toxicity

    USGS Publications Warehouse

    Barron, M.G.; Little, E.E.; Calfee, R.; Diamond, S.

    2000-01-01

    The spectra and intensity of solar radiation (solar spectral irradiance [SSI]) was quantified in selected aquatic habitats in the vicinity of an oil field on the California coast. Solar spectral irradiance measurements consisted of spectral scans (280-700 rim) and radiometric measurements of ultraviolet (UV): UVB (280-320 nm) and UVA (320-400 nm). Solar spectral irradiance measurements were taken at the surface and at various depths in two marsh ponds, a shallow wetland, an estuary lagoon, and the intertidal area of a high-energy sandy beach. Daily fluctuation in SSI showed a general parabolic relationship with time; maximum structure-activity relationship (SAR) was observed at approximate solar noon. Solar spectral irradiance measurements taken at 10-cm depth at approximate solar noon in multiple aquatic habitats exhibited only a twofold variation in visible light and UVA and a 4.5-fold variation in UVB. Visible light ranged from 11,000 to 19,000 ??W/cm2, UVA ranged from 460 to 1,100 ??W/cm2, and UVB ranged from 8.4 to 38 ??W/cm2. In each habitat, the attenuation of light intensity with increasing water depth was differentially affected over specific wavelengths of SSI. The study results allowed the development of environmentally realistic light regimes necessary for photoenhanced toxicity studies.

  14. Quantifying Florida Bay Habitat Suitability for Fishes and Invertebrates Under Climate Change Scenarios

    NASA Astrophysics Data System (ADS)

    Kearney, Kelly A.; Butler, Mark; Glazer, Robert; Kelble, Christopher R.; Serafy, Joseph E.; Stabenau, Erik

    2015-04-01

    The Florida Bay ecosystem supports a number of economically important ecosystem services, including several recreational fisheries, which may be affected by changing salinity and temperature due to climate change. In this paper, we use a combination of physical models and habitat suitability index models to quantify the effects of potential climate change scenarios on a variety of juvenile fish and lobster species in Florida Bay. The climate scenarios include alterations in sea level, evaporation and precipitation rates, coastal runoff, and water temperature. We find that the changes in habitat suitability vary in both magnitude and direction across the scenarios and species, but are on average small. Only one of the seven species we investigate ( Lagodon rhomboides, i.e., pinfish) sees a sizable decrease in optimal habitat under any of the scenarios. This suggests that the estuarine fauna of Florida Bay may not be as vulnerable to climate change as other components of the ecosystem, such as those in the marine/terrestrial ecotone. However, these models are relatively simplistic, looking only at single species effects of physical drivers without considering the many interspecific interactions that may play a key role in the adjustment of the ecosystem as a whole. More complex models that capture the mechanistic links between physics and biology, as well as the complex dynamics of the estuarine food web, may be necessary to further understand the potential effects of climate change on the Florida Bay ecosystem.

  15. Quantifying Florida Bay habitat suitability for fishes and invertebrates under climate change scenarios.

    PubMed

    Kearney, Kelly A; Butler, Mark; Glazer, Robert; Kelble, Christopher R; Serafy, Joseph E; Stabenau, Erik

    2015-04-01

    The Florida Bay ecosystem supports a number of economically important ecosystem services, including several recreational fisheries, which may be affected by changing salinity and temperature due to climate change. In this paper, we use a combination of physical models and habitat suitability index models to quantify the effects of potential climate change scenarios on a variety of juvenile fish and lobster species in Florida Bay. The climate scenarios include alterations in sea level, evaporation and precipitation rates, coastal runoff, and water temperature. We find that the changes in habitat suitability vary in both magnitude and direction across the scenarios and species, but are on average small. Only one of the seven species we investigate (Lagodon rhomboides, i.e., pinfish) sees a sizable decrease in optimal habitat under any of the scenarios. This suggests that the estuarine fauna of Florida Bay may not be as vulnerable to climate change as other components of the ecosystem, such as those in the marine/terrestrial ecotone. However, these models are relatively simplistic, looking only at single species effects of physical drivers without considering the many interspecific interactions that may play a key role in the adjustment of the ecosystem as a whole. More complex models that capture the mechanistic links between physics and biology, as well as the complex dynamics of the estuarine food web, may be necessary to further understand the potential effects of climate change on the Florida Bay ecosystem. PMID:25216988

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  19. MWSA's physical habitat approach - combining knowledge of habitat requirements with mechanisms of geomorphic and anthropogenic influence on stream channel form

    EPA Science Inventory

    Effective environmental policy decisions benefit from stream habitat information that is accurate, precise, and relevant. The recent National Wadeable Streams Assessment (NWSA) carried out by the U.S. EPA required physical habitat information sufficiently comprehensive to facilit...

  20. Quantifying habitat impacts of natural gas infrastructure to facilitate biodiversity offsetting.

    PubMed

    Jones, Isabel L; Bull, Joseph W; Milner-Gulland, Eleanor J; Esipov, Alexander V; Suttle, Kenwyn B

    2014-01-01

    Habitat degradation through anthropogenic development is a key driver of biodiversity loss. One way to compensate losses is "biodiversity offsetting" (wherein biodiversity impacted is "replaced" through restoration elsewhere). A challenge in implementing offsets, which has received scant attention in the literature, is the accurate determination of residual biodiversity losses. We explore this challenge for offsetting gas extraction in the Ustyurt Plateau, Uzbekistan. Our goal was to determine the landscape extent of habitat impacts, particularly how the footprint of "linear" infrastructure (i.e. roads, pipelines), often disregarded in compensation calculations, compares with "hub" infrastructure (i.e. extraction facilities). We measured vegetation cover and plant species richness using the line-intercept method, along transects running from infrastructure/control sites outward for 500 m, accounting for wind direction to identify dust deposition impacts. Findings from 24 transects were extrapolated to the broader plateau by mapping total landscape infrastructure network using GPS data and satellite imagery. Vegetation cover and species richness were significantly lower at development sites than controls. These differences disappeared within 25 m of the edge of the area physically occupied by infrastructure. The current habitat footprint of gas infrastructure is 220 ± 19 km(2) across the Ustyurt (total ∼ 100,000 km(2)), 37 ± 6% of which is linear infrastructure. Vegetation impacts diminish rapidly with increasing distance from infrastructure, and localized dust deposition does not conspicuously extend the disturbance footprint. Habitat losses from gas extraction infrastructure cover 0.2% of the study area, but this reflects directly eliminated vegetation only. Impacts upon fauna pose a more difficult determination, as these require accounting for behavioral and demographic responses to disturbance by elusive mammals, including threatened species. This study

  1. Quantifying habitat impacts of natural gas infrastructure to facilitate biodiversity offsetting.

    PubMed

    Jones, Isabel L; Bull, Joseph W; Milner-Gulland, Eleanor J; Esipov, Alexander V; Suttle, Kenwyn B

    2014-01-01

    Habitat degradation through anthropogenic development is a key driver of biodiversity loss. One way to compensate losses is "biodiversity offsetting" (wherein biodiversity impacted is "replaced" through restoration elsewhere). A challenge in implementing offsets, which has received scant attention in the literature, is the accurate determination of residual biodiversity losses. We explore this challenge for offsetting gas extraction in the Ustyurt Plateau, Uzbekistan. Our goal was to determine the landscape extent of habitat impacts, particularly how the footprint of "linear" infrastructure (i.e. roads, pipelines), often disregarded in compensation calculations, compares with "hub" infrastructure (i.e. extraction facilities). We measured vegetation cover and plant species richness using the line-intercept method, along transects running from infrastructure/control sites outward for 500 m, accounting for wind direction to identify dust deposition impacts. Findings from 24 transects were extrapolated to the broader plateau by mapping total landscape infrastructure network using GPS data and satellite imagery. Vegetation cover and species richness were significantly lower at development sites than controls. These differences disappeared within 25 m of the edge of the area physically occupied by infrastructure. The current habitat footprint of gas infrastructure is 220 ± 19 km(2) across the Ustyurt (total ∼ 100,000 km(2)), 37 ± 6% of which is linear infrastructure. Vegetation impacts diminish rapidly with increasing distance from infrastructure, and localized dust deposition does not conspicuously extend the disturbance footprint. Habitat losses from gas extraction infrastructure cover 0.2% of the study area, but this reflects directly eliminated vegetation only. Impacts upon fauna pose a more difficult determination, as these require accounting for behavioral and demographic responses to disturbance by elusive mammals, including threatened species. This study

  2. Quantifying habitat impacts of natural gas infrastructure to facilitate biodiversity offsetting

    PubMed Central

    Jones, Isabel L; Bull, Joseph W; Milner-Gulland, Eleanor J; Esipov, Alexander V; Suttle, Kenwyn B

    2014-01-01

    Habitat degradation through anthropogenic development is a key driver of biodiversity loss. One way to compensate losses is “biodiversity offsetting” (wherein biodiversity impacted is “replaced” through restoration elsewhere). A challenge in implementing offsets, which has received scant attention in the literature, is the accurate determination of residual biodiversity losses. We explore this challenge for offsetting gas extraction in the Ustyurt Plateau, Uzbekistan. Our goal was to determine the landscape extent of habitat impacts, particularly how the footprint of “linear” infrastructure (i.e. roads, pipelines), often disregarded in compensation calculations, compares with “hub” infrastructure (i.e. extraction facilities). We measured vegetation cover and plant species richness using the line-intercept method, along transects running from infrastructure/control sites outward for 500 m, accounting for wind direction to identify dust deposition impacts. Findings from 24 transects were extrapolated to the broader plateau by mapping total landscape infrastructure network using GPS data and satellite imagery. Vegetation cover and species richness were significantly lower at development sites than controls. These differences disappeared within 25 m of the edge of the area physically occupied by infrastructure. The current habitat footprint of gas infrastructure is 220 ± 19 km2 across the Ustyurt (total ∼ 100,000 km2), 37 ± 6% of which is linear infrastructure. Vegetation impacts diminish rapidly with increasing distance from infrastructure, and localized dust deposition does not conspicuously extend the disturbance footprint. Habitat losses from gas extraction infrastructure cover 0.2% of the study area, but this reflects directly eliminated vegetation only. Impacts upon fauna pose a more difficult determination, as these require accounting for behavioral and demographic responses to disturbance by elusive mammals, including threatened species

  3. Do Lanice conchilega (sandmason) aggregations classify as reefs? Quantifying habitat modifying effects

    NASA Astrophysics Data System (ADS)

    Rabaut, Marijn; Vincx, Magda; Degraer, Steven

    2009-03-01

    The positive effects of the tube dwelling polychaete Lanice conchilega for the associated benthic community emphasizes this bio-engineer’s habitat structuring capacity (Rabaut et al. in Estuar Coastal Shelf Sci, 2007). Therefore, L. conchilega aggregations are often referred to as reefs. The reef building capacity of ecosystem engineers is important for marine management as the recognition as reef builder will increase the protected status the concerned species. To classify as reefs however, bio-engineering activities need to significantly alter several habitat characteristics: elevation, sediment consolidation, spatial extent, patchiness, reef builder density, biodiversity, community structure, longevity and stability [guidelines to apply the EU reef-definition by Hendrick and Foster-Smith (J Mar Biol Assoc UK 86:665-677, 2006)]. This study investigates the physical and temporal characteristics of high density aggregations of L. conchilega. Results show that the elevation and sediment consolidation of the biogenic mounds was significantly higher compared to the surrounding unstructured sediment. Areas with L. conchilega aggregations tend to be extensive and patchiness is high (coverage 5-18%). The discussion of present study evaluates whether L. conchilega aggregations can be considered as reefs (discussing physical, biological and temporal characteristics). Individual aggregations were found to persist for several years if yearly renewal of existing aggregations through juvenile settlement occurred. This renewal is enhanced by local hydrodynamic changes and availability of attaching structures (adult tubes). We conclude that the application of the EU definition for reefs provides evidence that all physical and biological characteristics are present to classify L. conchilega as a reef builder. For temporal characteristics, this study shows several mechanisms exist for reefs to persist for a longer period of time. However, a direct evidence of long

  4. QUANTIFYING STREAM STRUCTURAL PHYSICAL HABITAT ATTRIBUTES USING LIDAR AND HYPERSPECTRAL IMAGERY

    EPA Science Inventory

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

  5. Terrestrial laser scanning for delineating in-stream boulders and quantifying habitat complexity measures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate stream topography measurement is important for many ecological applications such as hydraulic modeling and habitat characterization. Habitat complexity measures are often made using total station surveying or visual approximation, which can be subjective and have spatial resolution limitati...

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  9. Raccoon spatial requirements and multi-scale habitat selection within an intensively managed central Appalachian forest

    USGS Publications Warehouse

    Owen, Sheldon F.; Berl, Jacob L.; Edwards, John W.; Ford, W. Mark; Wood, Petra Bohall

    2015-01-01

    We studied a raccoon (Procyon lotor) population within a managed central Appalachian hardwood forest in West Virginia to investigate the effects of intensive forest management on raccoon spatial requirements and habitat selection. Raccoon home-range (95% utilization distribution) and core-area (50% utilization distribution) size differed between sexes with males maintaining larger (2×) home ranges and core areas than females. Home-range and core-area size did not differ between seasons for either sex. We used compositional analysis to quantify raccoon selection of six different habitat types at multiple spatial scales. Raccoons selected riparian corridors (riparian management zones [RMZ]) and intact forests (> 70 y old) at the core-area spatial scale. RMZs likely were used by raccoons because they provided abundant denning resources (i.e., large-diameter trees) as well as access to water. Habitat composition associated with raccoon foraging locations indicated selection for intact forests, riparian areas, and regenerating harvest (stands <10 y old). Although raccoons were able to utilize multiple habitat types for foraging resources, a selection of intact forest and RMZs at multiple spatial scales indicates the need of mature forest (with large-diameter trees) for this species in managed forests in the central Appalachians.

  10. Habitat requirements and expected distribution of Alaska coral. Final report

    SciTech Connect

    Cimberg, R.L.; Gerrodette, T.; Muzik, K.

    1981-10-01

    The objectives of the study are to provide the Alaskan OCS office of the Bureau of Land Management with: (1) a compilation and synthesis of information from the literature and other sources regarding the distribution, abundance, habitat requirements, and probable locations of corals along the Alaskan OCS waters; (2) a discussion of the potential effects of oil and gas exploration and development on corals; and (3) recommendations for further studies of corals and the effects of oil and gas exploration and development on these organisms.

  11. Quantifying landscape ruggedness for animal habitat analysis: A case study using bighorn sheep in the Mojave Desert

    USGS Publications Warehouse

    Sappington, J.M.; Longshore, K.M.; Thompson, D.B.

    2007-01-01

    Terrain ruggedness is often an important variable in wildlife habitat models. Most methods used to quantify ruggedness are indices derived from measures of slope and, as a result, are strongly correlated with slope. Using a Geographic Information System, we developed a vector ruggedness measure (VRM) of terrain based on a geomorphological method for measuring vector dispersion that is less correlated with slope. We examined the relationship of VRM to slope and to 2 commonly used indices of ruggedness in 3 physiographically different mountain ranges within the Mojave Desert of the southwestern United States. We used VRM, slope, distance to water, and springtime bighorn sheep (Ovis canadensis nelsoni) adult female locations to model sheep habitat in the 3 ranges. Using logistic regression, we determined that the importance of ruggedness in habitat selection remained consistent across mountain ranges, whereas the relative importance of slope varied according to the characteristic physiography of each range. Our results indicate that the VRM quantifies local variation in terrain more independently of slope than other methods tested, and that VRM and slope distinguish 2 different components of bighorn sheep habitat.

  12. Quantifying The Influence Of Time-Since-Creation On Benthic Secondary Production In Created Coastal Habitats

    EPA Science Inventory

    Wetland creation, enhancement, and restoration activities are commonly implemented to compensate for wetland loss or degradation in freshwater and coastal ecosystems. While assessments on structural condition are common in monitoring habitat restoration, functional equivalence i...

  13. Quantifying the co-evolution of morphology, hydraulics and spawning habitat in a recently restored gravel-bed river

    NASA Astrophysics Data System (ADS)

    Harrison, L. R.; Legleiter, C. J.; Wydzga, A. M.; Dunne, T.

    2008-12-01

    An emergent paradigm within restoration science is that restoration of natural physical processes is the best way to restore habitat for native organisms in degraded rivers. This concept, which underpins many restoration projects, is based on the notion that the establishment of an actively migrating, alluvial river channel-floodplain system will provide a number of desired ecological functions, each related to specific physical processes that occur at the habitat-scale. Here we quantify the rates of morphologic change, channel migration and the development of high-quality habitat, using a recently restored gravel-bed reach of the Merced River, California, USA. DEM-derived differences in bed elevation indicate that sediment storage accelerated processes of bar-building, pool scour, and bank erosion, leading to more asymmetric cross- sectional geometry. The volume of sediment stored on developing point bars was correlated with the migration distance of the outer bank, whereas in bends that have not accumulated sediment there has been little erosion, suggesting that channel migration was influenced by sediment supply as well as by channel curvature. The documented channel changes have had marked results on flow hydraulics, leading to decreased velocities over riffles and increased velocities in pools during low flow spawning conditions. Habitat modeling indicates that the quality of Chinook salmon (Oncorhynchus tshawytscha) spawning habitat has improved following the initial channel construction. These changes in morphology, hydraulics and habitat availability occurred primarily during two sustained periods of overbank flow. Collectively, these results highlight the importance of overbank flows and a sediment supply sufficient for bar growth in meander migration and creating channel complexity and high-quality habitat.

  14. Methods for Quantifying Shallow-Water Habitat Availability in the Missouri River

    SciTech Connect

    Hanrahan, Timothy P.; Larson, Kyle B.

    2012-04-09

    As part of regulatory requirements for shallow-water habitat (SWH) restoration, the U.S. Army Corps of Engineers (USACE) completes periodic estimates of the quantity of SWH available throughout the lower 752 mi of the Missouri River. To date, these estimates have been made by various methods that consider only the water depth criterion for SWH. The USACE has completed estimates of SWH availability based on both depth and velocity criteria at four river bends (hereafter called reference bends), encompassing approximately 8 river miles within the lower 752 mi of the Missouri River. These estimates were made from the results of hydraulic modeling of water depth and velocity throughout each bend. Hydraulic modeling of additional river bends is not expected to be completed for deriving estimates of available SWH. Instead, future estimates of SWH will be based on the water depth criterion. The objective of this project, conducted by the Pacific Northwest National Laboratory for the USACE Omaha District, was to develop geographic information system methods for estimating the quantity of available SWH based on water depth only. Knowing that only a limited amount of water depth and channel geometry data would be available for all the remaining bends within the lower 752 mi of the Missouri River, the intent was to determine what information, if any, from the four reference bends could be used to develop methods for estimating SWH at the remaining bends. Specifically, we examined the relationship between cross-section channel morphology and relative differences between SWH estimates based on combined depth and velocity criteria and the depth-only criterion to determine if a correction factor could be applied to estimates of SWH based on the depth-only criterion. In developing these methods, we also explored the applicability of two commonly used geographic information system interpolation methods (TIN and ANUDEM) for estimating SWH using four different elevation data

  15. Quantifying fluid and bed dynamics for characterizing benthic physical habitat in large rivers

    USGS Publications Warehouse

    Gaeuman, D.; Jacobson, R.B.

    2007-01-01

    Sturgeon use benthic habitats in and adjacent to main channels where environmental conditions can include bedload sediment transport and high near-bed flow velocities. Bed velocity measurements obtained with acoustic Doppler instruments provide a means to assess the concentration and velocity of sediment moving near the streambed, and are thus indicative of the bedload sediment transport rate, the near-bed flow velocity, and the stability of the substrate. Acoustic assessments of benthic conditions in the Missouri River were conducted at scales ranging from the stream reach to individual bedforms. Reach-scale results show that spatially-averaged bed velocities in excess of 0.5 m s-1 frequently occur in the navigation channel. At the local scale, bed velocities are highest near bedform crests, and lowest in the troughs. Low-velocity zones can persist in areas with extremely high mean bed velocities. Use of these low-velocity zones may allow sturgeon to make use of portions of the channel where the average conditions near the bed are severe. To obtain bed velocity measurements of the highest possible quality, it is necessary to extract bottom-track and GPS velocity information from the raw ADCP data files on a ping-by-ping basis. However, bed velocity measured from a point can also be estimated using a simplified method that is more easily implemented in the context of routine monitoring. The method requires only the transect distance and direction data displayed in standard ADCP data-logging software. Bed velocity estimates obtained using this method are usually within 5-10% of estimates obtained from ping-by-ping processing. ?? 2007 Blackwell Verlag.

  16. Quantifying changes in fish habitat use in coastal waters of Louisiana, United States of America: A hydroacoustic approach

    NASA Astrophysics Data System (ADS)

    Boswell, Kevin M.

    The development of reliable tools for identifying essential fish habitat (EFH) has proven problematic. Knowledge of the distribution and biomass of fishes over discrete habitat types is a prerequisite for effective use of EFH in the management of important commercial and recreational fish species. Resolution of the influence of habitat type and environmental factors on the distribution of fishes is confounded by limitations of traditional sampling gears. To date, hydroacoustic technology has been widely accepted as a tool for surveying fishery resources; however few studies have implemented acoustics in ultra shallow (<2 m) coastal waters. Efforts should be made to utilize hydroacoustics for quantifying changes in fish distributions within estuarine environments given the benefits provided through acoustic technology (e.g. ease of deployment, reduced sampling effort, and non-invasive sampling attributes). A technique was developed for acoustically sensing fishes in the shallow, turbid waters of Barataria Bay, Louisiana. A robust and lightweight remotely-controlled transducer platform was designed for deploying acoustic gear. Sources of scattering within the bay were identified through a series of exclosure net experiments designed to quantify potential effects of plankton and suspended solids on acoustic scattering. Analysis filters were developed to reduce the effects of bubble-induced noise, often observed during periods when wind speeds were greater than 4.5 m s-1. Side-aspect acoustic target strength-length and target strength-weight relationships were derived for tethered individuals of bay anchovy (Anchoa mitchilli) and Gulf menhaden ( Brevoortia patronus), with best fit models incorporating data from both species at the lateral perspective. Greater mean fish biomass and fish size were associated with higher salinity and oyster shell habitat in Barataria Bay when compared to nearby soft-bottom habitats. Results of acoustic mobile surveys of the Freeport

  17. Quantifying the role of woody debris in providing bioenergetically favorable habitat for juvenile salmon

    NASA Astrophysics Data System (ADS)

    Harrison, L.; Hafs, A. W.; Utz, R.; Dunne, T.

    2013-12-01

    The habitat complexity of a riverine ecosystem substantially influences aquatic communities, and especially the bioenergetics of drift feeding fish. We coupled hydrodynamic and bioenergetic models to assess the influence of habitat complexity, generated via large woody debris (LWD) additions, on juvenile Chinook salmon (Oncorhynchus tshawytscha) growth potential in a river that lacked large wood. Model simulations indicated that LWD diversified the flow field, creating pronounced velocity gradients, which enhanced fish feeding and resting activities at the micro-habitat (sub-meter) scale. Fluid drag created by individual wood structures was increased under higher wood loading rates, leading to a 5-19% reduction in the reach-averaged velocity. We found that wood loading was asymptotically related to the reach-scale growth potential, suggesting that the river became saturated with LWD and additional loading would produce minimal benefit. In our study reach, LWD additions could potentially quadruple the potential growth area available before that limit was reached. Wood depletion in the world's rivers has been widely documented, leading to widespread attempts by river managers to reverse this trend by adding wood to simplified aquatic habitats, though systematic prediction of the effects of wood on fish growth has not been previously accomplished. We offer a quantitative, theory-based approach for assessing the role of wood on habitat potential as it affects fish growth at the micro-habitat and reach-scales. Fig. 1. Predicted flow field and salmon growth potential maps produced from model simulations with no woody debris (Graphs A and D), a low density (Graphs B and E), and a high density (Graphs C and E) of woody debris.

  18. Quantifying overlap between the Deepwater Horizon oil spill and predicted bluefin tuna spawning habitat in the Gulf of Mexico

    PubMed Central

    Hazen, Elliott L.; Carlisle, Aaron B.; Wilson, Steven G.; Ganong, James E.; Castleton, Michael R.; Schallert, Robert J.; Stokesbury, Michael J. W.; Bograd, Steven J.; Block, Barbara A.

    2016-01-01

    Atlantic bluefin tuna (Thunnus thynnus) are distributed throughout the North Atlantic and are both economically valuable and heavily exploited. The fishery is currently managed as two spawning populations, with the GOM population being severely depleted for over 20 years. In April-August of 2010, the Deepwater Horizon oil spill released approximately 4 million barrels of oil into the GOM, with severe ecosystem and economic impacts. Acute oil exposure results in mortality of bluefin eggs and larvae, while chronic effects on spawning adults are less well understood. Here we used 16 years of electronic tagging data for 66 bluefin tuna to identify spawning events, to quantify habitat preferences, and to predict habitat use and oil exposure within Gulf of Mexico spawning grounds. More than 54,000 km2 (5%) of predicted spawning habitat within the US EEZ was oiled during the week of peak oil dispersal, with potentially lethal effects on eggs and larvae. Although the oil spill overlapped with a relatively small portion of predicted spawning habitat, the cumulative impact from oil, ocean warming and bycatch mortality on GOM spawning grounds may result in significant effects for a population that shows little evidence of rebuilding. PMID:27654709

  19. Quantifying overlap between the Deepwater Horizon oil spill and predicted bluefin tuna spawning habitat in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Hazen, Elliott L.; Carlisle, Aaron B.; Wilson, Steven G.; Ganong, James E.; Castleton, Michael R.; Schallert, Robert J.; Stokesbury, Michael J. W.; Bograd, Steven J.; Block, Barbara A.

    2016-09-01

    Atlantic bluefin tuna (Thunnus thynnus) are distributed throughout the North Atlantic and are both economically valuable and heavily exploited. The fishery is currently managed as two spawning populations, with the GOM population being severely depleted for over 20 years. In April-August of 2010, the Deepwater Horizon oil spill released approximately 4 million barrels of oil into the GOM, with severe ecosystem and economic impacts. Acute oil exposure results in mortality of bluefin eggs and larvae, while chronic effects on spawning adults are less well understood. Here we used 16 years of electronic tagging data for 66 bluefin tuna to identify spawning events, to quantify habitat preferences, and to predict habitat use and oil exposure within Gulf of Mexico spawning grounds. More than 54,000 km2 (5%) of predicted spawning habitat within the US EEZ was oiled during the week of peak oil dispersal, with potentially lethal effects on eggs and larvae. Although the oil spill overlapped with a relatively small portion of predicted spawning habitat, the cumulative impact from oil, ocean warming and bycatch mortality on GOM spawning grounds may result in significant effects for a population that shows little evidence of rebuilding.

  20. A National Approach for Mapping and Quantifying Habitat-based Biodiversity Metrics Across Multiple Spatial Scales

    EPA Science Inventory

    Ecosystem services, i.e., "services provided to humans from natural systems," have become a key issue of this century in resource management, conservation planning, and environmental decision analysis. Mapping and quantifying ecosystem services have become strategic national inte...

  1. Quantifying and Mapping Habitat-Based Biodiversity Metrics Within an Ecosystem Services Framework

    EPA Science Inventory

    Ecosystem services have become a key issue of this century in resource management, conservation planning, human well-being, and environmental decision analysis. Mapping and quantifying ecosystem services have become strategic national interests for integrating ecology with econom...

  2. Quantifying forest vertical structure to determine bird habitat quality in the Greenbelt Corridor, Denton, TX

    NASA Astrophysics Data System (ADS)

    Matsubayashi, Shiho

    This study presents the integration of light detection and range (LiDAR) and hyperspectral remote sensing to create a three-dimensional bird habitat map in the Greenbelt Corridor of the Elm Fork of the Trinity River. This map permits to examine the relationship between forest stand structure, landscape heterogeneity, and bird community composition. A biannual bird census was conducted at this site during the breeding seasons of 2009 and 2010. Census data combined with the three-dimensional map suggest that local breeding bird abundance, community structure, and spatial distribution patterns are highly influenced by vertical heterogeneity of vegetation surface. For local breeding birds, vertical heterogeneity of canopy surface within stands, connectivity to adjacent forest patches, largest forest patch index, and habitat (vegetation) types proved to be the most influential factors to determine bird community assemblages. Results also highlight the critical role of secondary forests to increase functional connectivity of forest patches. Overall, three-dimensional habitat descriptions derived from integrated LiDAR and hyperspectral data serve as a powerful bird conservation tool that shows how the distribution of bird species relates to forest composition and structure at various scales.

  3. Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin

    USGS Publications Warehouse

    Arkle, Robert S.; Pilliod, David S.; Hanser, Steven E.; Brooks, Matthew L.; Chambers, Jeanne C.; Grace, James B.; Knutson, Kevin C.; Pyke, David A.; Welty, Justin L.

    2014-01-01

    conditions, but in most climates, establishing forbs and reducing cheatgrass dominance is unlikely. Reestablishing sagebrush cover will require more than 20 years using past restoration methods. Given current fire frequencies and restoration capabilities, protection of landscapes containing a mix of dwarf sagebrush and big sagebrush steppe, minimal human development, and low non-native plant cover may provide the best opportunity for conservation of sage-grouse habitats.

  4. Forest loss and the biodiversity threshold: an evaluation considering species habitat requirements and the use of matrix habitats.

    PubMed

    Estavillo, Candelaria; Pardini, Renata; da Rocha, Pedro Luís Bernardo

    2013-01-01

    Habitat loss is the main driver of the current biodiversity crisis, a landscape-scale process that affects the survival of spatially-structured populations. Although it is well-established that species responses to habitat loss can be abrupt, the existence of a biodiversity threshold is still the cause of much controversy in the literature and would require that most species respond similarly to the loss of native vegetation. Here we test the existence of a biodiversity threshold, i.e. an abrupt decline in species richness, with habitat loss. We draw on a spatially-replicated dataset on Atlantic forest small mammals, consisting of 16 sampling sites divided between forests and matrix habitats in each of five 3600-ha landscapes (varying from 5% to 45% forest cover), and on an a priori classification of species into habitat requirement categories (forest specialists, habitat generalists and open-area specialists). Forest specialists declined abruptly below 30% of forest cover, and spillover to the matrix occurred only in more forested landscapes. Generalists responded positively to landscape heterogeneity, peaking at intermediary levels of forest cover. Open area specialists dominated the matrix and did not spillover to forests. As a result of these distinct responses, we observed a biodiversity threshold for the small mammal community below 30% forest cover, and a peak in species richness just above this threshold. Our results highlight that cross habitat spillover may be asymmetrical and contingent on landscape context, occurring mainly from forests to the matrix and only in more forested landscapes. Moreover, they indicate the potential for biodiversity thresholds in human-modified landscapes, and the importance of landscape heterogeneity to biodiversity. Since forest loss affected not only the conservation value of forest patches, but also the potential for biodiversity-mediated services in anthropogenic habitats, our work indicates the importance of proactive

  5. Two-dimensional hydrodynamic modeling to quantify effects of peak-flow management on channel morphology and salmon-spawning habitat in the Cedar River, Washington

    NASA Astrophysics Data System (ADS)

    Barnas, C. R.; Czuba, J. A.; Gendaszek, A. S.; Magirl, C. S.

    2010-12-01

    The Cedar River in Washington State originates on the western slope of the Cascade Range and provides the City of Seattle with most of its drinking water, while also supporting a productive salmon habitat. Water-resource managers require detailed information on how best to manage high-flow releases from Chester Morse Lake, a large reservoir on the Cedar River, during periods of heavy precipitation to minimize flooding, while mitigating negative effects on fish populations. Instream flow-management practices include provisions for adaptive management to promote and maintain healthy aquatic habitat in the river system. The current study is designed to understand the linkages between peak flow characteristics, geomorphic processes, riverine habitat, and biological responses. Specifically, two-dimensional hydrodynamic modeling is used to simulate and quantify the effects of the peak-flow magnitude, duration, and frequency on the channel morphology and salmon-spawning habitat. Two study reaches, representative of the typical geomorphic and ecologic characteristics of the Cedar River, were selected for the modeling. Detailed bathymetric data, collected with a real-time kinematic global positioning system and an acoustic Doppler current profiler, were combined with a LiDAR-derived digital elevation model in the overbank area to develop a computational mesh. The model is used to simulate water velocity, benthic shear stress, flood inundation, and morphologic changes in the gravel-bedded river under the current and alternative flood-release strategies. Simulations of morphologic change and salmon-redd scour by floods of differing magnitude and duration enable water-resource managers to incorporate model simulation results into adaptive management of peak flows in the Cedar River.

  6. Two-dimensional hydrodynamic modeling to quantify effects of peak-flow management on channel morphology and salmon-spawning habitat in the Cedar River, Washington

    USGS Publications Warehouse

    Czuba, Christiana; Czuba, Jonathan A.; Gendaszek, Andrew S.; Magirl, Christopher S.

    2010-01-01

    The Cedar River in Washington State originates on the western slope of the Cascade Range and provides the City of Seattle with most of its drinking water, while also supporting a productive salmon habitat. Water-resource managers require detailed information on how best to manage high-flow releases from Chester Morse Lake, a large reservoir on the Cedar River, during periods of heavy precipitation to minimize flooding, while mitigating negative effects on fish populations. Instream flow-management practices include provisions for adaptive management to promote and maintain healthy aquatic habitat in the river system. The current study is designed to understand the linkages between peak flow characteristics, geomorphic processes, riverine habitat, and biological responses. Specifically, two-dimensional hydrodynamic modeling is used to simulate and quantify the effects of the peak-flow magnitude, duration, and frequency on the channel morphology and salmon-spawning habitat. Two study reaches, representative of the typical geomorphic and ecologic characteristics of the Cedar River, were selected for the modeling. Detailed bathymetric data, collected with a real-time kinematic global positioning system and an acoustic Doppler current profiler, were combined with a LiDAR-derived digital elevation model in the overbank area to develop a computational mesh. The model is used to simulate water velocity, benthic shear stress, flood inundation, and morphologic changes in the gravel-bedded river under the current and alternative flood-release strategies. Simulations of morphologic change and salmon-redd scour by floods of differing magnitude and duration enable water-resource managers to incorporate model simulation results into adaptive management of peak flows in the Cedar River. PDF version of a presentation on hydrodynamic modelling in the Cedar River in Washington state. Presented at the American Geophysical Union Fall Meeting 2010.

  7. Assessment of Habitat and Streamflow Requirements for Habitat Protection, Usquepaug-Queen River, Rhode Island, 1999-2000

    USGS Publications Warehouse

    Armstrong, David S.; Parker, Gene W.

    2003-01-01

    species that would have been expected to occur in this area. Streamflow records from the gaging station Usquepaug River near Usquepaug were used to (1) determine streamflow requirements for habitat protection by use of the Tennant method, and (2) define a flow regime that mimics the river's natural flow regime by use of the Range of Variability Approach. The Tennant streamflow requirement, defined as 30 percent of the mean annual flow, was 0.64 cubic feet per second per square mile (ft3/s/mi2). This requirement should be considered an initial estimate because flows measured at the Usquepaug River gaging station are reduced by water withdrawals upstream from the gage. The streamflow requirements may need to be revised once a watershed-scale precipitationrunoff model of the Usquepaug River is complete and a simulation of streamflows without water withdrawals has been determined. Streamflow requirements for habitat protection were also determined at seven riffle sites by use of the Wetted-Perimeter and R2Cross methods. Two of these sites were on the mainstem Usquepaug River, one was on the mainstem Queen River, and four were on tributaries and the headwaters of the Queen River. Median streamflow requirements for habitat protection for these sites were 0.41 (ft3/s)/mi2, determined by the Wetted-Perimeter method and 0.72 ft3/s/mi2, determined by the R2Cross method.

  8. Quantifying Seagrass Light Requirements Using an Algorithm to Spatially Resolve Depth of Colonization

    EPA Science Inventory

    The maximum depth of colonization (Zc) is a useful measure of seagrass growth that describes response to light attenuation in the water column. However, lack of standardization among methods for estimating Zc has limited the description of habitat requirements at spatial scales m...

  9. Habitat requirements of New Mexico’s endangered salamanders

    USGS Publications Warehouse

    Ramotnik, Cindy A.; Scott, N.J.

    1988-01-01

    We measured habitat components for two state-listed endangered salamanders in New Mexico in 1986 and 1987. Both species are restricted to mesic environments within high-elevation, mixed coniferous forests. Steep slope and high elevation were the most useful variables for predicting the occurrence of Jemez Mountains salamanders and Sacramento Mountain salamanders, respectively. Although the discriminant models show some predictive value in detecting salamanders based on habitat variables, we believe that the best survey technique is ground-truth surveys in wet weather. A better fit of the discriminant models might be obtained by including variables not measured e.g., fire and logging history, and soil characteristics. We offer interim management guidelines as a result of our analysis.

  10. Representing connectivity: quantifying effective habitat availability based on area and connectivity for conservation status assessment and recovery

    PubMed Central

    Tumas, Hayley R.; Marsden, Brittany W.

    2014-01-01

    We apply a comprehensive suite of graph theoretic metrics to illustrate how landscape connectivity can be effectively incorporated into conservation status assessments and in setting conservation objectives. These metrics allow conservation practitioners to evaluate and quantify connectivity in terms of representation, resiliency, and redundancy and the approach can be applied in spite of incomplete knowledge of species-specific biology and dispersal processes. We demonstrate utility of the graph metrics by evaluating changes in distribution and connectivity that would result from implementing two conservation plans for three endangered plant species (Erigeron parishii, Acanthoscyphus parishii var. goodmaniana, and Eriogonum ovalifolium var. vineum) relative to connectivity under current conditions. Although distributions of the species differ from one another in terms of extent and specific location of occupied patches within the study landscape, the spatial scale of potential connectivity in existing networks were strikingly similar for Erigeron and Eriogonum, but differed for Acanthoscyphus. Specifically, patches of the first two species were more regularly distributed whereas subsets of patches of Acanthoscyphus were clustered into more isolated components. Reserves based on US Fish and Wildlife Service critical habitat designation would not greatly contribute to maintain connectivity; they include 83–91% of the extant occurrences and >92% of the aerial extent of each species. Effective connectivity remains within 10% of that in the whole network for all species. A Forest Service habitat management strategy excluded up to 40% of the occupied habitat of each species resulting in both range reductions and loss of occurrences from the central portions of each species’ distribution. Overall effective network connectivity was reduced to 62–74% of the full networks. The distance at which each CHMS network first became fully connected was reduced relative to the

  11. Representing connectivity: quantifying effective habitat availability based on area and connectivity for conservation status assessment and recovery.

    PubMed

    Neel, Maile; Tumas, Hayley R; Marsden, Brittany W

    2014-01-01

    We apply a comprehensive suite of graph theoretic metrics to illustrate how landscape connectivity can be effectively incorporated into conservation status assessments and in setting conservation objectives. These metrics allow conservation practitioners to evaluate and quantify connectivity in terms of representation, resiliency, and redundancy and the approach can be applied in spite of incomplete knowledge of species-specific biology and dispersal processes. We demonstrate utility of the graph metrics by evaluating changes in distribution and connectivity that would result from implementing two conservation plans for three endangered plant species (Erigeron parishii, Acanthoscyphus parishii var. goodmaniana, and Eriogonum ovalifolium var. vineum) relative to connectivity under current conditions. Although distributions of the species differ from one another in terms of extent and specific location of occupied patches within the study landscape, the spatial scale of potential connectivity in existing networks were strikingly similar for Erigeron and Eriogonum, but differed for Acanthoscyphus. Specifically, patches of the first two species were more regularly distributed whereas subsets of patches of Acanthoscyphus were clustered into more isolated components. Reserves based on US Fish and Wildlife Service critical habitat designation would not greatly contribute to maintain connectivity; they include 83-91% of the extant occurrences and >92% of the aerial extent of each species. Effective connectivity remains within 10% of that in the whole network for all species. A Forest Service habitat management strategy excluded up to 40% of the occupied habitat of each species resulting in both range reductions and loss of occurrences from the central portions of each species' distribution. Overall effective network connectivity was reduced to 62-74% of the full networks. The distance at which each CHMS network first became fully connected was reduced relative to the full

  12. Habitat requirements for Chesapeake Bay living resources. Chesapeake Bay Program Agreement Commitment Report

    SciTech Connect

    Not Available

    1988-01-01

    This report provides guidance, along with EPA Water Quality Criteria and State Water Quality Standards and other information, to help refine and improve Chesapeake Bay Agreement programs designed to provide for the restoration and protection of living resources, their habitats, and ecological relationships. The Living Resources Task Force, an ad hoc workgroup of the Chesapeake Bay Program, was charged by the Chesapeake Bay Implementation Committee to develop an approach to define habitat objectives for the living resources of the Bay. The report was produced by the Task Force to establish a technically defensible approach in setting regional habitat objectives for Chesapeake Bay by initially assembling habitat requirement for individual target species. It summarizes the results of the Task Force efforts to date and provides the basis for future refinement of the habitat objectives approach.

  13. Status and Habitat Requirements of White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1989-1990 Annual Report.

    SciTech Connect

    Nigro, Anthony A.

    1990-09-01

    We report on our progress from April 1989 through March 1990 on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW), Washington Department of Fisheries (WDF), US Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS). Study objectives addressed by each agency are to describe the life history and population dynamics of subadults and adults between Bonneville and McNary dams and evaluate the need and identify potential methods for protecting, mitigating and enhancing populations downstream from McNary Dam, to describe the white sturgeon recreational fishery between Bonneville and McNary dams, describe reproductive and early life history characteristics downstream from Bonneville Dam and describe life history and population dynamics of subadults and adults downstream from Bonneville Dam, to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available between Bonneville and McNary dams, and to describe reproduction and early life history characteristics, define habitat requirements for spawning and rearing and quantify extent of habitat available downstream from Bonneville Dam. Our approach is to work concurrently downstream and upstream from Bonneville Dam. Upstream from Bonneville Dam we began work in the Dalles Reservoir in 1987 and expanded efforts to Bonneville Reservoir in 1988 and John Day Reservoir in 1989. Highlights from this work is also included. 47 refs., 33 figs., 66 tabs.

  14. Assessment of Habitat, Fish Communities, and Streamflow Requirements for Habitat Protection, Ipswich River, Massachusetts, 1998-99

    USGS Publications Warehouse

    Armstrong, David S.; Richards, Todd A.; Parker, Gene W.

    2001-01-01

    The relations among stream habitat, fish communities, and hydrologic conditions were investigated in the Ipswich River Basin in northeastern Massachusetts. Data were assessed from 27 sites on the mainstem of the Ipswich River from July to September 1998 and from 10 sites on 5 major tributaries in July and August 1999. Habitat assessments made in 1998 determined that in a year with sustained streamflow for most of the summer, the Ipswich River contains diverse, high-quality aquatic habitat. Channel types are predominantly low gradient glides, pools, and impoundments, with a sandy streambed and a forest or shrub riparian zone. Features that provide fish habitat are located mostly along stream margins; these features include overhanging brush, undercut banks, exposed roots, and woody debris. These habitat features decrease in availability to aquatic communities with declining streamflows and generally become unavailable after streamflows drop to the point where the edge of water recedes from the stream banks.The mainstem and tributaries were sampled to determine fish species composition, relative abundance, and length frequency. Fish sampling indicates that the fish community in the Ipswich River is currently a warm-water fish community dominated by pond-type fish. However, historical temperature data, and survival of stocked trout in the mainstem Ipswich into late summer of 1998, indicate that the Ipswich River potentially could support cold-water fish species if adequate flows are maintained. Dominant fish species sampled in the mainstem Ipswich River were redfin pickerel (Esox americanus), American eel (Anguilla rostrata), and pumpkinseed (Lepomis gibbosus), which together represented 41, 22, and 10 percent, respectively, of 4,745 fish sampled. The fish communities of the mainstem and tributaries contained few fluvial-dependent or fluvial-specialist species (requiring flow), and were dominated by macrohabitat generalists (tolerant of low-flow, warm-water, and

  15. Habitat Suitability Index Models: Marten

    USGS Publications Warehouse

    Allen, Arthur W.

    1982-01-01

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

  16. Habitat Suitability Index Models: Veery

    USGS Publications Warehouse

    Sousa, Patrick J.

    1982-01-01

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

  17. Marine mammal and habitat monitoring: Requirements; principles; needs; and approaches

    SciTech Connect

    Swartz, S.L.; Hofman, R.J.

    1991-08-01

    The paper discusses the intents and provisions of section 101(a)(5) of the Marine Mammal Protection Act which allows the Secretaries of the Interior and Commerce to authorize the unintentional taking of small numbers of marine mammals incidental to offshore oil and gas development and other such activities. It explains the rationale for and describes the types of site-specific and population monitoring programs required to document the manner and level of take and to verify that the take has negligible effects on the distribution, size, and productivity of the affected species and populations.

  18. Habitat requirements and burrowing depths of rodents in relation to shallow waste burial sites

    SciTech Connect

    Gano, K.A.; States, J.B.

    1982-05-01

    The purpose of this paper is to provide a review of the literature and summarize information on factors affecting habitat selection and maximum recorded burrowing depths for representative small mammals that we consider most likely to inhibit waste burial sites in arid and semi-arid regions of the West. The information is intended for waste management designers who need to know what to expect from small mammals that may be present at a particular site. Waste repositories oculd be designed to exclude the deep burrowing rodents of a region by creating an unattractive habitat over the waste. Summaries are given for habitat requirements of each group along with generalized modifications that could be employed to deter habitation. Representatives from the major groups considered to be deep burrowers are discussed. Further, detailed information about a particular species can be obtained from the references cited.

  19. Applying coupled flow and sediment-transport models to understanding habitat requirements and availability.

    NASA Astrophysics Data System (ADS)

    McDonald, R. R.; Nelson, J. M.

    2006-12-01

    Understanding the relationship between habitat requirements and the magnitude and duration of flow and sediment supply is an important component of both habitat assessment and restoration strategies. Fish habitat is often defined in terms of velocity, depth or substrate composition; locations where combinations of these factors meet habitat requirements depend on channel morphology, flow magnitude, and, in rivers with mobile beds, time-varying change in channel morphology. Because coupled multi-dimensional flow and sediment transport models provide spatially distributed information on flow and other hydraulic quantities, they permit detailed delineation of habitat. Furthermore, they can be used directly to understand how flow magnitude and duration and sediment supply control channel change and habitat availability. We present an example to illustrate how such models can be used in investigations of fish spawning habitat and availability. In the Kootenai River, Idaho, comparison of observed spawning locations with model derived spatial distributions of depths and velocities suggests that white sturgeon utilize the largest available velocity and depth within an 18-kilometer spawning reach over a range of discharges. This is a somewhat more selective criterion than a simple specification of a range of velocity or depth magnitudes, which illustrates the importance of evaluating habitat over a full range of discharge magnitudes. Observations also suggest that spawning currently occurs over a sandy substrate resulting in suffocation of eggs and little to no recruitment of juvenile sturgeon since closure of Libby Dam in 1974. Extending flow modeling to incorporate sediment- transport and bed evolution suggests that a relatively high magnitude long duration discharge can remove sandy substrate, thereby exposing a coarse gravel lag deposit in some areas and providing needed spawning substrate. These results were qualitatively validated through video surveys of channel

  20. Quantifying flow-dependent changes in subyearling fall chinook salmon rearing habitat using two-dimensional spatially explicit modeling

    USGS Publications Warehouse

    Tiffan, K.F.; Garland, R.D.; Rondorf, D.W.

    2002-01-01

    We used an analysis based on a geographic information system (GIS) to determine the amount of rearing habitat and stranding area for subyearling fall chinook salmon Oncorhynchus tshawytscha in the Hanford Reach of the Columbia River at steady-state flows ranging from 1,416 to 11,328 m3/s. High-resolution river channel bathymetry was used in conjunction with a two-dimensional hydrodynamic model to estimate water velocities, depths, and lateral slopes throughout our 33-km study area. To relate the probability of fish presence in nearshore habitats to measures of physical habitat, we developed a logistic regression model from point electrofishing data. We only considered variables that were compatible with a GIS and therefore excluded other variables known to be important to juvenile salmonids. Water velocity and lateral slope were the only two variables included in our final model. The amount of available rearing habitat generally decreased as flow increased, with the greatest decreases occurring between 1,416 and 4,814 m3/s. When river discharges were between 3,682 and 7,080 m3/s, flow fluctuations of 566 m3/s produced the smallest change in available rearing area (from -6.3% to +6.8% of the total). Stranding pool area was greatly reduced at steady-state flows exceeding 4,531 m3/s, but the highest net gain in stranding area was produced by 850 m3/s decreases in flow when river discharges were between 5,381 and 5,664 m3/s. Current measures to protect rearing fall chinook salmon include limiting flow fluctuations at Priest Rapids Dam to 850 m3/s when the dam is spilling water and when the weekly flows average less than 4,814 m3/s. We believe that limiting flow fluctuations at all discharges would further protect subyearling fall chinook salmon.

  1. Conceptual model for quantifying pre-smolt production from flow-dependent physical habitat and water temperature

    USGS Publications Warehouse

    Williamson, S. C.; Bartholow, J. M.; Stalnaker, C. B.

    1993-01-01

    A conceptual model has been developed to test river regulation concepts by linking physical habitat and water temperature with salmonid population and production in cold water streams. Work is in progress to examine numerous questions as part of flow evaluation and habitat restoration programmes in the Trinity River of California and elsewhere. For instance, how much change in pre-smolt chinook salmon (Oncorhynchus tshawytscha) production in the Trinity River would result from a different annual instream allocation (i.e. up or down from 271 × 106 m3 released in the late 1980s) and how much change in pre-smolt production would result from a different release pattern (i.e. different from the 8.5 m3 s−1 year-round release). The conceptual model is being used to: design, integrate and improve young-of-year population data collection efforts; test hypotheses that physical habitat significantly influences movement, growth and mortality of salmonid fishes; and analyse the relative severity of limiting factors during each life stage. The conceptual model, in conjunction with previously developed tools in the Instream Flow Incremental Methodology, should provide the means to more effectively manage a fishery resource below a regulated reservoir and to provide positive feedback to planning of annual reservoir operations.

  2. Habitat area requirements of breeding forest birds of the middle Atlantic states

    USGS Publications Warehouse

    Robbins, Chandler S.; Dawson, Deanna K.; Dowell, Barbara A.

    1989-01-01

    Conservation of birds requires an understanding of their nesting requirements, including area as well as structural characteristics of the habitat. Previous studies have shown that many neotropical migrant bird species seem to depend on extensive forested areas, but the specific area requirements of individual species have not been clarified sufficiently to aid in design and management of effective preserves. For this 5-year study, bird and vegetation data were obtained at 469 points in forests ranging in area from 0.1 ha to more than 3,000 ha in Maryland and adjacent states. Data were analyzed first by stepwise regression to identify habitat factors that had the greatest influence on relative abundance of each bird species. In the relatively undisturbed mature forests studied, degree of isolation and area were significant predictors of relative abundance for more bird species than were any habitat variables. For species for which forest area was a significant predictor of abundance, we used logistic regression to examine the relationship between forest area and the probability of detecting the species. In managing forest lands for wildlife, top priority should go toward providing for the needs of area-sensitive or rare species rather than increasing species diversity per se. Avian species that occur in small and disturbed forests are generalists that are adapted to survival under edge conditions and need no special assistance from man. Forest reserves with thousands of hectares are required to have the highest probability of providing for the least common species of forest birds in a region. However, if preservation of large contiguous forest tracts is not a realistic option, results of this study suggest 2 alternative approaches. First, if other habitat attributes also are considered, smaller forests may provide suitable breeding sites for relatively rare species. Second, smaller tracts in close proximity to other forests may serve to attract or retain area

  3. Using videography to quantify landscape-level availability of habitat for grazers: An example with emperor geese in western Alaska

    USGS Publications Warehouse

    Lake, B.C.; Lindberg, M.S.; Schmutz, J.A.; Anthony, R.M.; Broerman, F.J.

    2006-01-01

    We present a videography approach to estimating large-scale availability of grazing lawns, an important food resource used by broods of emperor geese (Chen canagica) on the Yukon-Kuskokwim Delta, Alaska. Sampling was conducted in 1999, 2003, and 2004 at six locations that encompassed ???40% of the North American population of breeding emperor geese. We conducted ground truthing in 2003 and 2004 to estimate how accurately grazing lawn was classified. Overall, classification accuracy for grazing lawn and non-grazing lawn habitat was greater than 91%. Availability of grazing lawns was stable among years, but varied both among and within locations. Some locations have up to three times as much available grazing lawn, which in combination with densities of geese, likely represents dramatic variation in per capita food availability. Our results suggest that videography is a useful way to sample quickly across a large region and accurately identify fine-scale habitats. We present its use for estimating the availability of a preferred food resource for emperor geese, but the method could be applied to many other cases.

  4. Dispersal ability and habitat requirements determine landscape-level genetic patterns in desert aquatic insects.

    PubMed

    Phillipsen, Ivan C; Kirk, Emily H; Bogan, Michael T; Mims, Meryl C; Olden, Julian D; Lytle, David A

    2015-01-01

    Species occupying the same geographic range can exhibit remarkably different population structures across the landscape, ranging from highly diversified to panmictic. Given limitations on collecting population-level data for large numbers of species, ecologists seek to identify proximate organismal traits-such as dispersal ability, habitat preference and life history-that are strong predictors of realized population structure. We examined how dispersal ability and habitat structure affect the regional balance of gene flow and genetic drift within three aquatic insects that represent the range of dispersal abilities and habitat requirements observed in desert stream insect communities. For each species, we tested for linear relationships between genetic distances and geographic distances using Euclidean and landscape-based metrics of resistance. We found that the moderate-disperser Mesocapnia arizonensis (Plecoptera: Capniidae) has a strong isolation-by-distance pattern, suggesting migration-drift equilibrium. By contrast, population structure in the flightless Abedus herberti (Hemiptera: Belostomatidae) is influenced by genetic drift, while gene flow is the dominant force in the strong-flying Boreonectes aequinoctialis (Coleoptera: Dytiscidae). The best-fitting landscape model for M. arizonensis was based on Euclidean distance. Analyses also identified a strong spatial scale-dependence, where landscape genetic methods only performed well for species that were intermediate in dispersal ability. Our results highlight the fact that when either gene flow or genetic drift dominates in shaping population structure, no detectable relationship between genetic and geographic distances is expected at certain spatial scales. This study provides insight into how gene flow and drift interact at the regional scale for these insects as well as the organisms that share similar habitats and dispersal abilities.

  5. Virtual environment to quantify the influence of colour stimuli on the performance of tasks requiring attention

    PubMed Central

    2011-01-01

    Background Recent studies indicate that the blue-yellow colour discrimination is impaired in ADHD individuals. However, the relationship between colour and performance has not been investigated. This paper describes the development and the testing of a virtual environment that is capable to quantify the influence of red-green versus blue-yellow colour stimuli on the performance of people in a fun and interactive way, being appropriate for the target audience. Methods An interactive computer game based on virtual reality was developed to evaluate the performance of the players. The game's storyline was based on the story of an old pirate who runs across islands and dangerous seas in search of a lost treasure. Within the game, the player must find and interpret the hints scattered in different scenarios. Two versions of this game were implemented. In the first, hints and information boards were painted using red and green colours. In the second version, these objects were painted using blue and yellow colours. For modelling, texturing, and animating virtual characters and objects the three-dimensional computer graphics tool Blender 3D was used. The textures were created with the GIMP editor to provide visual effects increasing the realism and immersion of the players. The games were tested on 20 non-ADHD volunteers who were divided into two subgroups (A1 and A2) and 20 volunteers with ADHD who were divided into subgroups B1 and B2. Subgroups A1 and B1 used the first version of the game with the hints painted in green-red colors, and subgroups A2 and B2 the second version using the same hints now painted in blue-yellow. The time spent to complete each task of the game was measured. Results Data analyzed with ANOVA two-way and posthoc TUKEY LSD showed that the use of blue/yellow instead of green/red colors decreased the game performance of all participants. However, a greater decrease in performance could be observed with ADHD participants where tasks, that require

  6. Establishing Reference Condition for Streambed Mobility: Quantifying the Effect of Form Roughness From Stream Habitat Survey Data

    NASA Astrophysics Data System (ADS)

    Kaufmann, P. R.; Faustini, J. M.; Larsen, D. P.; Shirazi, M. A.

    2008-12-01

    The size and mobility of streambed particles are sensitive to changes in the balance between sediment supply and transport. Therefore, changes in mobility can be an indicator of natural or anthropogenic alterations in this balance. Predictions of the critical diameter for mobility of stream bed particles (Dc) typically depend on estimates of bed shear stress that are based on stream gradient, depth, and the specific weight of water. In complex natural streams, depth at a given discharge increases with hydraulic resistance, but reach-average shear stress exerted on bed particles declines if depth increases are the result of form resistance associated with large roughness elements such as wood and bedforms. Published, practical approaches to quantify the reduction in this component of shear stress are lacking. We derived an adjustment of bankfull shear stress and Dc that multiplies the bankfull hydraulic radius (Rbf) by the one-third power of the ratio of particle-derived resistance to total hydraulic resistance, (Cp/Ct)1/3. We computed Cp using a Keulegan equation relating resistance to relative submergence of bed particles and Ct from thalweg mean and residual depths and large wood volume. Measured total resistance was determined by dye-transit over a wide range of discharge, residual pools, and wood in natural stream channels. We tested our estimates of Ct using data from a survey of 104 wadeable streams in the Pacific Northwest, USA. Estimated bankfull Ct ranged from 0.002 to 1.68 (friction factors 0.016 to 13). Stream discharges calculated using Ct compared favorably with velocity- area measurements of discharge at low flow, and published data on 1 to 2-year recurrence floods. The median ratio of particle- to total resistance (Cp/Ct) was 6.7% at bankfull flows, showing that in half of these streams at least 93% of resistance resulted from large roughness elements including longitudinal bedforms, pools and wood. Bankfull Dc ranged very fine gravel to large

  7. Defining environmental flows requirements at regional scale by using meso-scale habitat models and catchments classification

    NASA Astrophysics Data System (ADS)

    Vezza, Paolo; Comoglio, Claudio; Rosso, Maurizio

    2010-05-01

    oxygen were collected for each sampled area and considered as independent variables. According to the MesoHABSIM method, we performed a stepwise forward logistic regression in order to build up a biological model identifying the habitat characteristics mostly used by a target fish. For each stream we predicted changes in habitat area over a range of discharges by building the habitat-flow rating curves. Finally, in order to define a regional criteria needed to fulfill environmental flow requirements, we split the study domain according to the regression tree classification criterion defining homogenous sub-regions distinct on both environmental flows and catchment characteristics.

  8. Habitat and logistic support requirements for the initiation of a space manufacturing enterprise

    NASA Technical Reports Server (NTRS)

    Vajk, J. P.; Engel, J. H.; Shettler, J. A.

    1979-01-01

    A detailed scenario for the initiation of a space manufacturing enterprise using lunar materials to construct solar power satellites (SPS) was developed, with particular attention to habitat design and logistic support requirements. If SPS's can be constructed exclusively from lunar materials, the entire enterprise can be initiated in a 7 year period of launch activity (beginning as early as 1985) using the Space Shuttle and a low-cost, Shuttle-derived heavy lift vehicle. If additional chemical feedstocks must be imported from earth in significant quantities, it may be necessary to bring the next-generation launch vehicle (single-stage-to-orbit) into operation by 1991. The scenario presented features use of the mass-driver reaction engine for orbit-to-orbit transfer of cargos and makes extensive use of the expendable Shuttle external propellant tanks.

  9. Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season.

    PubMed

    Webber, Alyson F; Heath, Julie A; Fischer, Richard A

    2013-04-01

    Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, and brood-rearing and used multi-season occupancy models to examine whether human disturbance, habitat features, or both influenced site occupancy, colonization (probability of transition from an unoccupied site to an occupied site), and extinction (probability of transition from an occupied site to an unoccupied site). Snowy plover site occupancy and colonization was negatively associated with human disturbance and site extinction was positively associated with human disturbance. Interdune vegetation had a negative effect on occupancy and colonization, indicating that plovers were less likely to use areas with uniform, dense vegetation among dunes. Also, dune shape, beach debris, and access to low-energy foraging areas influenced site occupancy, colonization, and extinction. Plovers used habitat based on beach characteristics that provided stage-specific resource needs; however, human disturbance was the strongest predictor of site occupancy. In addition, vegetation plantings used to enhance dune rehabilitation may negatively impact plover site occupancy. Management actions that decrease human disturbance, such as symbolic fencing and signage, may increase the amount of breeding habitat available to snowy plovers on the Florida Panhandle and in other areas with high human

  10. Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season

    PubMed Central

    Webber, Alyson F; Heath, Julie A; Fischer, Richard A

    2013-01-01

    Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, and brood-rearing and used multi-season occupancy models to examine whether human disturbance, habitat features, or both influenced site occupancy, colonization (probability of transition from an unoccupied site to an occupied site), and extinction (probability of transition from an occupied site to an unoccupied site). Snowy plover site occupancy and colonization was negatively associated with human disturbance and site extinction was positively associated with human disturbance. Interdune vegetation had a negative effect on occupancy and colonization, indicating that plovers were less likely to use areas with uniform, dense vegetation among dunes. Also, dune shape, beach debris, and access to low-energy foraging areas influenced site occupancy, colonization, and extinction. Plovers used habitat based on beach characteristics that provided stage-specific resource needs; however, human disturbance was the strongest predictor of site occupancy. In addition, vegetation plantings used to enhance dune rehabilitation may negatively impact plover site occupancy. Management actions that decrease human disturbance, such as symbolic fencing and signage, may increase the amount of breeding habitat available to snowy plovers on the Florida Panhandle and in other areas with high human

  11. Modeling spring habitat requirements of the endangered brown eared pheasant Crossoptilon mantchuricum in the Huanglong Mountains, Shaanxi Province, China.

    PubMed

    Li, Hongqun; Yue, Bisong; Lian, Zhenmin; Zhao, Hongfeng; Zhao, Delong; Xiao, Xiangming

    2012-09-01

    A detailed understanding of the habitat needs of brown eared pheasants (Crossoptilon mantchuricum) is essential for conserving the species. We carried out field surveys in the Huanglong Mountains of Shaanxi Province, China, from March to June in 2007 and 2008. We arrayed a total of 206 grid plots (200 × 200 m) along transects in 2007 and 2008 and quantified a suite of environmental variables for each one. In the optimal logistic regression model, the most important variables for brown eared pheasants were slope degree, tree cover, distance to nearest water, cover and depth of fallen leaves. Hosmer and Leweshow goodness-of-fit tests explained that logistic models for the species were good fits. The model suggested that spring habitat selection of the brown eared pheasant was negatively related to distance to nearest water and slope degree, and positively to cover of trees and cover and depth of fallen leaves. In addition, the observed detected and undetected grids in 2007 did not show significant differences with predictions based on the model. These results showed that the model could well predict the habitat selection of brown eared pheasants. Based on these predictive models, we suggest that habitat management plans incorporating this new information can now focus more effectively on restrictions on the number of tourists entering the nature reserve, prohibition of firewood collection, livestock grazing, and medicinal plant harvesting by local residents in the core areas, protection of mixed forest and sources of the permanent water in the reserve, and use of alternatives to firewood.

  12. Quantifying changes in flooding and habitats in the Tonle Sap Lake (Cambodia) caused by water infrastructure development and climate change in the Mekong Basin.

    PubMed

    Arias, Mauricio E; Cochrane, Thomas A; Piman, Thanapon; Kummu, Matti; Caruso, Brian S; Killeen, Timothy J

    2012-12-15

    The economic value of the Tonle Sap Lake Floodplain to Cambodia is arguably among the highest provided to a nation by a single ecosystem around the world. Nonetheless, the Mekong River Basin is changing rapidly due to accelerating water infrastructure development (hydropower, irrigation, flood control, and water supply) and climate change, bringing considerable modifications to the flood pulse of the Tonle Sap Lake in the foreseeable future. This paper presents research conducted to determine how the historical flooding regime, together with human action, influenced landscape patterns of habitats in the Tonle Sap Lake, and how these habitats might shift as a result of hydrological changes. Maps of water depth, annual flood duration, and flood frequency were created for recent historical hydrological conditions and for simulated future scenarios of water infrastructure development and climate change. Relationships were then established between the historical flood maps and land cover, and these were subsequently applied to assess potential changes to habitat cover in future decades. Five habitat groups were clearly distinguishable based on flood regime, physiognomic patterns, and human activity: (1) Open water, flooded for 12 months in an average hydrological year; (2) Gallery forest, with flood duration of 9 months annually; (3) Seasonally flooded habitats, flooded 5-8 months and dominated by shrublands and grasslands; (4) transitional habitats, flooded 1-5 months and dominated by abandoned agricultural fields, receding rice/floating rice, and lowland grasslands; and (5) Rainfed habitats, flooded up to 1 month and consisting mainly of wet season rice fields and village crops. It was found that water infrastructure development could increase the area of open water (+18 to +21%) and the area of rainfed habitats (+10 to +14%), while reducing the area covered with seasonally flooded habitats (-13 to -22%) and gallery forest (-75 to -83%). Habitat cover shifts as a

  13. Quantifying the thermal heat requirement of Brassica in assessing biophysical parameters under semi-arid microenvironments

    NASA Astrophysics Data System (ADS)

    Adak, Tarun; Chakravarty, N. V. K.

    2010-07-01

    Evaluation of the thermal heat requirement of Brassica spp. across agro-ecological regions is required in order to understand the further effects of climate change. Spatio-temporal changes in hydrothermal regimes are likely to affect the physiological growth pattern of the crop, which in turn will affect economic yields and crop quality. Such information is helpful in developing crop simulation models to describe the differential thermal regimes that prevail at different phenophases of the crop. Thus, the current lack of quantitative information on the thermal heat requirement of Brassica crops under debranched microenvironments prompted the present study, which set out to examine the response of biophysical parameters [leaf area index (LAI), dry biomass production, seed yield and oil content] to modified microenvironments. Following 2 years of field experiments on Typic Ustocrepts soils under semi-arid climatic conditions, it was concluded that the Brassica crop is significantly responsive to microenvironment modification. A highly significant and curvilinear relationship was observed between LAI and dry biomass production with accumulated heat units, with thermal accumulation explaining ≥80% of the variation in LAI and dry biomass production. It was further observed that the economic seed yield and oil content, which are a function of the prevailing weather conditions, were significantly responsive to the heat units accumulated from sowing to 50% physiological maturity. Linear regression analysis showed that growing degree days (GDD) could indicate 60-70% variation in seed yield and oil content, probably because of the significant response to differential thermal microenvironments. The present study illustrates the statistically strong and significant response of biophysical parameters of Brassica spp. to microenvironment modification in semi-arid regions of northern India.

  14. Quantifying the Dimensions of Water Crisis in India: Spatial Water Deficits and Storage Requirements

    NASA Astrophysics Data System (ADS)

    Perveen, S.; Devineni, N.; Lall, U.

    2010-12-01

    India is facing threats of mounting water resources crisis with growing concerns on the reliable supply of water for various agricultural, industrial and domestic needs. High inter-annual rainfall variability, limited storage infrastructure to buffer the variations, and increasing consumptive uses across the country exacerbates the situation further. In this study, a detailed quantitative assessment of the water availability and storage requirements for India is presented. Considering the climate variability over a century time scale and the current water demands, Potential Storage Index (PSI) is developed for all districts in India using the sequent peak algorithm. The Potential Storage Index highlights the districts with high water stress, thus identifying the regions where water demand management or new storage infrastructure is needed. Preliminary analysis shows that the regions under high stress are the regions with high inter-annual variability in rainfall and depleted groundwater aquifers. The sensitivity of the model and applications to irrigated and rainfed crop management are presented. The results of the analysis are further used to assess differential vulnerability of particular sectors within the nation which can serve as a basis for targeting policy interventions.

  15. Preliminary assessment of streamflow requirements for habitat protection for selected sites on the Assabet and Charles rivers, eastern Massachusetts

    USGS Publications Warehouse

    Parker, Gene W.; Armstrong, David S.

    2002-01-01

    Streamflow requirements for habitat protection were determined at several critical riffle reaches in the Assabet River and Charles River Basins. The R2Cross and Wetted-Perimeter methods yielded median streamflow requirements of 0.75 cubic feet per second per square mile (ft3/s/mi2) and 0.13 ft3/s/mi2, respectively. Three study reaches are on tributaries to the Assabet River (Danforth Brook, Great Brook, and Elizabeth Brook), two are on the mainstem of the Charles River, and one is on a tributary to the Charles River (Mine Brook). The strength of the R2Cross and Wetted-Perimeter methods is that they may be applied at ungaged locations. A Range of Variability Approach analysis was conducted on a common 30-year period of record from 1969 to 1998 for five mostly unaltered flow, streamgaging stations. The discharge range defined by the median R2Cross and Wetted-Perimeter streamflow requirements brackets the interquartile range for the median of monthly-mean flows during the summer low-flow period, as defined by the Range of Variability Approach analysis of five streamgaging stations. The median R2Cross streamflow requirement for the five riffles compares very closely to the median Tennant 40-percent of the mean annual flow requirement for good habitat condition. The median Wetted-Perimeter streamflow requirement compares closely to the median Tennant 10-percent of the mean annual-flow requirement for a poor habitat condition. Tennant and Range of Variability Approach methods require continuous discharge records for analysis.

  16. Biodiversity: Habitat Suitability

    EPA Science Inventory

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

  17. Biodiversity conservation across taxa and landscapes requires many small as well as single large habitat fragments.

    PubMed

    Rösch, Verena; Tscharntke, Teja; Scherber, Christoph; Batáry, Péter

    2015-09-01

    Agricultural intensification has been shown to reduce biodiversity through processes such as habitat degradation and fragmentation. We tested whether several small or single large habitat fragments (re-visiting the 'single large or several small' debate) support more species across a wide range of taxonomic groups (plants, leafhoppers, true bugs, snails). Our study comprised 14 small (<1 ha) and 14 large (1.5-8 ha) fragments of calcareous grassland in Central Germany along orthogonal gradients of landscape complexity and habitat connectivity. Each taxon was sampled on six plots per fragment. Across taxa, species richness did not differ between large and small fragments, whereas species-area accumulation curves showed that both overall and specialist species richness was much higher on several small fragments of calcareous grassland than on few large fragments. On average, 85% of the overall species richness was recorded on all small fragments taken together (4.6 ha), whereas the two largest ones (15.1 ha) only accounted for 37% of the species. This could be due to the greater geographic extent covered by many small fragments. However, community composition differed strongly between large and small fragments, and some of the rarest specialist species appeared to be confined to large fragments. The surrounding landscape did not show any consistent effects on species richness and community composition. Our results show that both single large and many small fragments are needed to promote landscape-wide biodiversity across taxa. We therefore question the focus on large fragments only and call for a new diversified habitat fragmentation strategy for biodiversity conservation.

  18. The chimpanzee nest quantified: morphology and ecology of arboreal sleeping platforms within the dry habitat site of Toro-Semliki Wildlife Reserve, Uganda.

    PubMed

    Samson, David R

    2012-10-01

    The nightly construction of a sleeping platform (SP) or "nest" is widely regarded as a universal behavior among great apes, yet SP structural morphology has been incompletely quantified to date. This is in part due to the inherent difficulties of gathering empirical data on arboreally sited SPs. I gathered quantitative structural data on SPs (n = 65) at the Toro-Semliki Wildlife Reserve from May to June 2008 and from August 2010 to January 2011. I measured SP length (semi-major axis length), width (semi-minor axis length), radii (length from the surface center to the rim edge 45° from the axis), depth (width of the concavity from the surface center to the parallel rim), and thickness (ventral center to the dorsal underside of the SP). SP complexity was defined with a scored index. SP complexity was found to be correlated with SP circumference, surface area, mass, proportion of soft leafy material to hard woody material, number of frame support branches used in its construction, and other measures that are argued to index "comfort." In addition, the height of the tree canopy above the SP was negatively correlated with SP complexity. Greater complexity (and therefore stability) is argued to maintain SP integrity, stability and restraint in the face of greater wind speeds, thereby reducing the probability of falls. Given the observation that males site SPs lower than females (Fruth and Hohmann, Ethology 94:113-126, 1994; Brownlow et al., Am J Primatol 55:49-55, 2001), and that SP diameters were greater for SPs sited low in the canopy at Semliki, it is inferred that more massive males benefit from lower climbing expenses and greater stability. These data support Baldwin and colleagues' (Primates 22:474-486, 1981) hypothesis that the principal advantage of SPs over open-branch sleeping sites is the greater stability required by large-bodied great apes.

  19. The Effects of Reducing the Structural Mass of the Transit Habitat on the Cryogenic Propellant Required for a Human Phobos Mission

    NASA Technical Reports Server (NTRS)

    Zipay, John Joseph

    2016-01-01

    A technique for rapidly determining the relationship between the pressurized volume, structural mass and the cryogenic propellant required to be delivered to Earth orbit for a Mars Transit Habitat is provided. This technique is based on assumptions for the required delta-V's, the Exploration Upper Stage performance and the historical structural masses for human spacecraft from Mercury Program through the International Space Station. If the Mars Transit Habitat is constructed from aluminum, structural mass estimates based on the habitat pressurized volume are accurate to within 15%. Other structural material options for the Mars Transit Habitat are also evaluated. The results show that small, achievable reductions in the structural mass of the Transit Habitat can save tens of thousands of pounds of cryogenic propellant that need to be delivered to Earth orbit for a human Phobos Mission.

  20. The Effects of Reducing the Structural Mass of the Transit Habitat on the Cryogenic Propellant Required for a Human Phobos Mission

    NASA Technical Reports Server (NTRS)

    Zipay, John J.

    2016-01-01

    A technique for rapidly determining the relationship between the pressurized volume, structural mass and the cryogenic propellant required to be delivered to Earth orbit for a Mars Transit Habitat is provided. This technique is based on assumptions for the required delta-V's, the Exploration Upper Stage performance and the historical structural masses for human spacecraft from Mercury Program through the International Space Station. If the Mars Transit Habitat is constructed from aluminum, structural mass estimates based on the habitat pressurized volume are accurate to within 15 percent. Other structural material options for the Mars Transit Habitat are also evaluated. The results show that small, achievable reductions in the structural mass of the Transit Habitat can save tens of thousands of pounds of cryogenic propellant that need to be delivered to Earth orbit for a human Phobos Mission.

  1. Chesapeake bay submerged aquatic vegetation habitat requirements and restoration targets: A technical synthesis

    SciTech Connect

    Batiuk, R.A.; Orth, R.J.; Moore, K.A.; Dennison, W.C.; Stevenson, J.C.

    1992-12-01

    Chesapeake Bay, one of the world's largest estuaries, has experienced deterioration of water quality from nutrient enrichment, resulting in anoxic or hypoxic conditions and declines in living resources. Determination of relationships between water quality and various living resources provides a mechanism of relating anthropogenic inputs to the 'health' of Chesapeake Bay. One of the major factors contributing to the high productivity of Chesapeake Bay has been the historical abundance of submerged aquatic vegetation (SAV). SAV in Chesapeake Bay include some twenty freshwater and marine species of rooted, flowering plants. SAV provide food for waterfowl and are critical habitat for shellfish and finfish. SAV also affect nutrient cycling, sediment stability, and water turbidity. The primary objective of the SAV Technical Synthesis is to establish the quantitative levels of relevant water quality parameters necessary to support continued survival, propagation, and restoration of SAV.

  2. Development of a Habitat Suitability Index Model for the Sage Sparrow on the Hanford Site

    SciTech Connect

    Duberstein, Corey A.; Simmons, Mary Ann; Sackschewsky, Michael R.; Becker, James M.

    2008-01-01

    Mitigation threshold guidelines for the Hanford Site are based on habitat requirements of the sage sparrow (Amphispiza belli) and only apply to areas with a mature sagebrush (Artemisia tridentata) overstory and a native understory. The sage sparrow habitat requirements are based on literature values and are not specific to the Hanford Site. To refine these guidelines for the Site, a multi-year study was undertaken to quantify habitat characteristics of sage sparrow territories. These characteristics were then used to develop a habitat suitability index (HSI) model which can be used to estimate the habitat value of specific locations on the Site.

  3. Quantifying the net benefit impacts of the Troy Waste Water Treatment Plant on Steelhead Habitat in the West Fork Little Bear Creek drainage

    NASA Astrophysics Data System (ADS)

    Sanchez-Murillo, R.; Brooks, E. S.; Boll, J.

    2010-12-01

    Discharge of waste water treatment plants (WWTPs) typically is viewed to result in water quality impairment. However, WWTPs can also be a source of nutrients to enhance the salmonid food web as well as an efficient way to maintain acceptable water temperature regimes and flow conditions during summer. We observed this paradox in West Fork Little Bear Creek (WFLB) in the City of Troy, Idaho. Despite the nutrient load, the WFLB had the highest Steelhead trout density in the watershed, with a mean density of 13.2 fish/100 m2. The objective of this project was to utilize a water quality model, QUAL2kw, and an ecology assessment to examine how the nutrient load from the WWTP affects: a) habitat conditions for steelhead juveniles, and b) physic-chemical parameters. Four monitoring stations were installed from May through November in 2009 and 2010. An undisturbed creek was used as a control site in 2010. Dissolved oxygen (DO), electrical conductivity, temperature, and discharge were measured continuously at each monitoring station. Weekly samples were collected at each monitoring station and analyzed for nitrate, nitrite, ammonia, total Kjeldahl nitrogen, total phosphorous, and orthophosphates. In 2010, Chlorophyll a was analyzed weekly, while bottom algae biomass was determined monthly. Results show that during summer months, the WWTP provides the majority of the flow (0.1 cfs) in the creek. Water samples and DO measurements taken 200 m downstream of the plant during late summer months indicate that nitrification process leads to low DO level well below the state standard of 6 mg/L for cold water biota. However dissolved oxygen levels recover within 1 km downstream. Discharge data suggest that without the flow from the treatment most of the creek would dry during late summer months. Abundance of macroinverbrates, high primary productivity, and sustained flow during summer suggests that the effluent from the WWTP is a net benefit to the Steelhead habitat in the basin

  4. Habitat requirements of the endangered California freshwater shrimp (Syncaris pacifica) in lagunitas and Olema creeks, Marin County, California, USA

    USGS Publications Warehouse

    Martin, Barbara A.; Saiki, Michael K.; Fong, Darren

    2009-01-01

    This study was conducted to better understand the habitat requirements and environmental limiting factors of Syncaris pacifica, the California freshwater shrimp. This federally listed endangered species is native to perennial lowland streams in a few watersheds in northern California. Field sampling occurred in Lagunitas and Olema creeks at seasonal intervals from February 2003 to November 2004. Ten glides, five pools, and five riffles served as fixed sampling reaches, with eight glides, four pools, and four riffles located in Lagunitas Creek and the remainder in Olema Creek. A total of 1773 S. pacifica was counted during this study, all of which were captured along vegetated banks in Lagunitas Creek. Syncaris pacifica was most numerous in glides (64), then in pools (31), and lastly in riffles (5). According to logistic regression analysis, S. pacifica was mostly associated with submerged portions of streambank vegetation (especially overhanging vegetation such as ferns and blackberries, emergent vegetation such as sedge and brooklime, and fine roots associated with water hemlock, willow, sedge, and blackberries) along with low water current velocity and a sandy substrate. These seemingly favorable habitat conditions for S. pacifica were present in glides and pools in Lagunitas Creek, but not in Olema Creek. ?? 2009 The Crustacean Society.

  5. Effects of Mitigative Measures on Productivity of White Sturgeon Populations in the Columbia River Downstream from McNary Dam; Determine Status and Habitat Requirements of White Sturgeon Populations in the Columbia and Snake Rivers Upstream from the McNary Dam, 1994-1995 Annual Report.

    SciTech Connect

    Beiningen, Kirk T.

    1996-03-01

    The author reports on progress from April 1994 through March 1995 of research on white sturgeon in the lower Columbia River. The study began in July 1986 and is a cooperative effort of federal, state and tribal fisheries entities to determine the (1) the status and habitat requirements, and (2) the effects of mitigative measures on productivity of white sturgeon populations in the lower Columbia River. This report describes activities conducted during the third year of this contract's second phase. Information was collected, analyzed, and evaluated on sub-adult and adult life histories, population dynamics, quantity and quality of habitat, and production enhancement strategies. The report is divided into sections that evaluate success of developing and implementing a management plan for white sturgeon; evaluate growth, mortality, and contributions to fisheries of juvenile white sturgeon transplanted from areas downstream; describe the life history and population dynamics of sub-adult a nd adult white sturgeon; define habitat requirements for spawning and rearing of white sturgeon and quantify the extent of habitat available; describe reproductive and early life history characteristics of white sturgeon; and quantify physical habitat used by spawning and rearing white sturgeon in the free-flowing portion of the Columbia River.

  6. A physiological approach to quantifying thermal habitat quality for redband rainbow trout (Oncorhynchus mykiss gairdneri) in the south Fork John Day River, Oregon

    USGS Publications Warehouse

    Feldhaus, J.W.; Heppell, S.A.; Li, H.; Mesa, M.G.

    2010-01-01

    We examined tissue-specific levels of heat shock protein 70 (hsp70) and whole body lipid levels in juvenile redband trout (Oncorhynchus mykiss gairdneri) from the South Fork of the John Day River (SFJD), Oregon, with the goal of determining if these measures could be used as physiological indicators of thermal habitat quality for juvenile redband trout. Our objectives were to determine the hsp70 induction temperature in liver, fin, and white muscle tissue and characterize the relation between whole body lipids and hsp70 for fish in the SFJD. We found significant increases in hsp70 levels between 19 and 22??C in fin, liver, and white muscle tissue. Maximum hsp70 levels in liver, fin, and white muscle tissue occurred when mean weekly maximum temperatures (MWMT) exceeded 20-22??C. In general, the estimated hsp70 induction temperature for fin and white muscle tissue was higher than liver tissue. Whole body lipid levels began to decrease when MWMT exceeded 20. 4??C. There was a significant interaction between temperature and hsp70 in fin and white muscle tissue, but not liver tissue. Collectively, these results suggest that increased hsp70 levels in juvenile redband trout are symptomatic of thermal stress, and that energy storage capacity decreases with this stress. The possible decrease in growth potential and fitness for thermally stressed individuals emphasizes the physiological justification for thermal management criteria in salmon-bearing streams. ?? Springer Science+Business Media B.V. 2010.

  7. Predictive Seagrass Habitat Model

    EPA Science Inventory

    Restoration of ecosystem services provided by seagrass habitats in estuaries requires a firm understanding of the modes of action of multiple interacting stressors including nutrients, climate change, coastal land-use change, and habitat modification. We explored the application...

  8. Habitat requirements of the pulmonate land snails Trochulus oreinos oreinos and Cylindrus obtusus endemic to the Northern Calcareous Alps, Austria

    PubMed Central

    Duda, Michael; Kruckenhauser, Luise; Haring, Elisabeth; Sattmann, Helmut

    2014-01-01

    The habitat needs and potential threats to Trochulus oreinos oreinos (Wagner 1915) and Cylindrus obtusus (Draparnaud 1805) were assessed by comparing vegetation maps and our own records. We selected four sites from which we had adequate samples and for which exact vegetation maps were available: the mountains Hoch-schwab, Schneealpe, Rax and Schneeberg. Both taxa prefer open dry alpine grassland with diggable soil and/or stones. T. oreinos oreinos is restricted to subalpine and alpine boulder societies and Caricetum firmae. While C. obtusus dwells on several communities of plants, it seems to be bound to unconsolidated stony ground. As both taxa prefer naturally forest-free areas, they are not affected by structural changes of the habitat, such as reforestation caused by the abandonment of grazing and the shift of vegetation zones. But it has to be considered that T. oreinos oreinos and C. obtusus are limited by microclimatic factors, as they prefer cooler habitats. The mountains Schneealpe, Rax and Schneeberg, reaching barely 2000 m in height, are on the climatic limit of the species distribution. Therefore, the investigated taxa are vulnerable to the upward shift of climate zones. T. oreinos oreinos shows striking similarities in its habitat preference to the Swiss endemic T. biconicus, as both taxa prefer the same dry alpine habitats which are quite different to those of other representatives of the genus, which prefer damp habitats. PMID:25729612

  9. Determining habitat quality for species that demonstrate dynamic habitat selection

    USGS Publications Warehouse

    Beerens, James; Frederick, Peter C; Noonburg, Erik G; Gawlik, Dale E.

    2015-01-01

    Determining habitat quality for wildlife populations requires relating a species' habitat to its survival and reproduction. Within a season, species occurrence and density can be disconnected from measures of habitat quality when resources are highly seasonal, unpredictable over time, and patchy. Here we establish an explicit link among dynamic selection of changing resources, spatio-temporal species distributions, and fitness for predictive abundance and occurrence models that are used for short-term water management and long-term restoration planning. We used the wading bird distribution and evaluation models (WADEM) that estimate (1) daily changes in selection across resource gradients, (2) landscape abundance of flocks and individuals, (3) conspecific foraging aggregation, and (4) resource unit occurrence (at fixed 400 m cells) to quantify habitat quality and its consequences on reproduction for wetland indicator species. We linked maximum annual numbers of nests detected across the study area and nesting success of Great Egrets (Ardea alba), White Ibises (Eudocimus albus), and Wood Storks (Mycteria americana) over a 20-year period to estimated daily dynamics of food resources produced by WADEM over a 7490 km2 area. For all species, increases in predicted species abundance in March and high abundance in April were strongly linked to breeding responses. Great Egret nesting effort and success were higher when birds also showed greater conspecific foraging aggregation. Synthesis and applications: This study provides the first empirical evidence that dynamic habitat selection processes and distributions of wading birds over environmental gradients are linked with reproductive measures over periods of decades. Further, predictor variables at a variety of temporal (daily-multiannual) resolutions and spatial (400 m to regional) scales effectively explained variation in ecological processes that change habitat quality. The process used here allows managers to develop

  10. Determining habitat quality for species that demonstrate dynamic habitat selection.

    PubMed

    Beerens, James M; Frederick, Peter C; Noonburg, Erik G; Gawlik, Dale E

    2015-12-01

    Determining habitat quality for wildlife populations requires relating a species' habitat to its survival and reproduction. Within a season, species occurrence and density can be disconnected from measures of habitat quality when resources are highly seasonal, unpredictable over time, and patchy. Here we establish an explicit link among dynamic selection of changing resources, spatio-temporal species distributions, and fitness for predictive abundance and occurrence models that are used for short-term water management and long-term restoration planning. We used the wading bird distribution and evaluation models (WADEM) that estimate (1) daily changes in selection across resource gradients, (2) landscape abundance of flocks and individuals, (3) conspecific foraging aggregation, and (4) resource unit occurrence (at fixed 400 m cells) to quantify habitat quality and its consequences on reproduction for wetland indicator species. We linked maximum annual numbers of nests detected across the study area and nesting success of Great Egrets (Ardea alba), White Ibises (Eudocimus albus), and Wood Storks (Mycteria americana) over a 20-year period to estimated daily dynamics of food resources produced by WADEM over a 7490 km(2) area. For all species, increases in predicted species abundance in March and high abundance in April were strongly linked to breeding responses. Great Egret nesting effort and success were higher when birds also showed greater conspecific foraging aggregation. Synthesis and applications: This study provides the first empirical evidence that dynamic habitat selection processes and distributions of wading birds over environmental gradients are linked with reproductive measures over periods of decades. Further, predictor variables at a variety of temporal (daily-multiannual) resolutions and spatial (400 m to regional) scales effectively explained variation in ecological processes that change habitat quality. The process used here allows managers to

  11. Quantifying the influence of imbrication on forces required to initiate motion of coarse-grained sediment on natural river bars

    NASA Astrophysics Data System (ADS)

    Sanguinito, S.; Johnson, J. P.

    2010-12-01

    The goal of this study is to investigate the impact that the stacking and imbrication of clasts has on forces required to initiate particle motion. Equations for predicting clast motion, such as the Shields parameter, typically assume that clast weight is the factor that controls mobility. We explore the hypothesis that the overlapping of clasts increases the forces required to dislodge particles, making individual clasts less mobile and interlocked beds more stable. Specific variables in our analysis include grain size, clast shape, and degree of clast burial. Field measurements were taken at two, subaerially exposed bar reaches along the Colorado River in Texas. These sites, the Roy G. Guerrero Park and Marble Falls contain median grain sizes of 3.7 and 6.4 mm, respectively. Small hooks were glued to individual clasts without disrupting their positions, and peak forces required to quasi-statically dislodge each clast via slow vertical lifting were measured using an FDIX force gage. Repeated lift tests done on several 100 % exposed clasts indicate that the method is repeatable, and the slow lifting simply measures the weight of the clast if it is not held down by surrounding grains. We parameterize the additional force required to mobilize a clast beyond its weight as the "excess force ratio", defined as the peak vertical dislodgement force divided by the weight of the clast. In addition, exposed surfaces were sprayed with colored dye before clasts were dislodged, and image analysis was used to calculate the ratio of exposed surface area to total surface area for individual clasts. Our data find no correlation between Corey shape factor and excess force ratio, which suggests particle shape is not a controlling variable for forces resisting motion. Particle size and mass constrain the excess force ratio; larger clasts (>1000 g) require forces equal to only one or two times their weight while smaller clasts (<500 g) can require forces up to five times their weight

  12. Mean deformation metrics for quantifying 3D cell–matrix interactions without requiring information about matrix material properties

    PubMed Central

    Stout, David A.; Bar-Kochba, Eyal; Estrada, Jonathan B.; Toyjanova, Jennet; Kesari, Haneesh; Reichner, Jonathan S.; Franck, Christian

    2016-01-01

    Mechanobiology relates cellular processes to mechanical signals, such as determining the effect of variations in matrix stiffness with cell tractions. Cell traction recorded via traction force microscopy (TFM) commonly takes place on materials such as polyacrylamide- and polyethylene glycol-based gels. Such experiments remain limited in physiological relevance because cells natively migrate within complex tissue microenvironments that are spatially heterogeneous and hierarchical. Yet, TFM requires determination of the matrix constitutive law (stress–strain relationship), which is not always readily available. In addition, the currently achievable displacement resolution limits the accuracy of TFM for relatively small cells. To overcome these limitations, and increase the physiological relevance of in vitro experimental design, we present a new approach and a set of associated biomechanical signatures that are based purely on measurements of the matrix's displacements without requiring any knowledge of its constitutive laws. We show that our mean deformation metrics (MDM) approach can provide significant biophysical information without the need to explicitly determine cell tractions. In the process of demonstrating the use of our MDM approach, we succeeded in expanding the capability of our displacement measurement technique such that it can now measure the 3D deformations around relatively small cells (∼10 micrometers), such as neutrophils. Furthermore, we also report previously unseen deformation patterns generated by motile neutrophils in 3D collagen gels. PMID:26929377

  13. Mean deformation metrics for quantifying 3D cell-matrix interactions without requiring information about matrix material properties.

    PubMed

    Stout, David A; Bar-Kochba, Eyal; Estrada, Jonathan B; Toyjanova, Jennet; Kesari, Haneesh; Reichner, Jonathan S; Franck, Christian

    2016-03-15

    Mechanobiology relates cellular processes to mechanical signals, such as determining the effect of variations in matrix stiffness with cell tractions. Cell traction recorded via traction force microscopy (TFM) commonly takes place on materials such as polyacrylamide- and polyethylene glycol-based gels. Such experiments remain limited in physiological relevance because cells natively migrate within complex tissue microenvironments that are spatially heterogeneous and hierarchical. Yet, TFM requires determination of the matrix constitutive law (stress-strain relationship), which is not always readily available. In addition, the currently achievable displacement resolution limits the accuracy of TFM for relatively small cells. To overcome these limitations, and increase the physiological relevance of in vitro experimental design, we present a new approach and a set of associated biomechanical signatures that are based purely on measurements of the matrix's displacements without requiring any knowledge of its constitutive laws. We show that our mean deformation metrics (MDM) approach can provide significant biophysical information without the need to explicitly determine cell tractions. In the process of demonstrating the use of our MDM approach, we succeeded in expanding the capability of our displacement measurement technique such that it can now measure the 3D deformations around relatively small cells (∼10 micrometers), such as neutrophils. Furthermore, we also report previously unseen deformation patterns generated by motile neutrophils in 3D collagen gels. PMID:26929377

  14. Using urban forest assessment tools to model bird habitat potential

    USGS Publications Warehouse

    Lerman, Susannah B.; Nislow, Keith H.; Nowak, David J.; Destefano, Stephen; King, David I.; Jones-Farrand, D. Todd

    2014-01-01

    The alteration of forest cover and the replacement of native vegetation with buildings, roads, exotic vegetation, and other urban features pose one of the greatest threats to global biodiversity. As more land becomes slated for urban development, identifying effective urban forest wildlife management tools becomes paramount to ensure the urban forest provides habitat to sustain bird and other wildlife populations. The primary goal of this study was to integrate wildlife suitability indices to an existing national urban forest assessment tool, i-Tree. We quantified available habitat characteristics of urban forests for ten northeastern U.S. cities, and summarized bird habitat relationships from the literature in terms of variables that were represented in the i-Tree datasets. With these data, we generated habitat suitability equations for nine bird species representing a range of life history traits and conservation status that predicts the habitat suitability based on i-Tree data. We applied these equations to the urban forest datasets to calculate the overall habitat suitability for each city and the habitat suitability for different types of land-use (e.g., residential, commercial, parkland) for each bird species. The proposed habitat models will help guide wildlife managers, urban planners, and landscape designers who require specific information such as desirable habitat conditions within an urban management project to help improve the suitability of urban forests for birds.

  15. Habitat Suitability Index Models: Pronghorn

    USGS Publications Warehouse

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

    1984-01-01

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

  16. Climate Tolerances and Habitat Requirements Jointly Shape the Elevational Distribution of the American Pika (Ochotona princeps), with Implications for Climate Change Effects.

    PubMed

    Yandow, Leah H; Chalfoun, Anna D; Doak, Daniel F

    2015-01-01

    Some of the most compelling examples of ecological responses to climate change are elevational range shifts of individual species, which have been observed throughout the world. A growing body of evidence, however, suggests substantial mediation of simple range shifts due to climate change by other limiting factors. Understanding limiting factors for a species within different contexts, therefore, is critical for predicting responses to climate change. The American pika (Ochotona princeps) is an ideal species for investigating distributions in relation to climate because of their unusual and well-understood natural history as well as observed shifts to higher elevation in parts of their range. We tested three hypotheses for the climatic or habitat characteristics that may limit pika presence and abundance: summer heat, winter snowpack, and forage availability. We performed these tests using an index of pika abundance gathered in a region where environmental influences on pika distribution have not been well-characterized. We estimated relative pika abundance via scat surveys and quantified climatic and habitat characteristics across two North-Central Rocky Mountain Ranges, the Wind River and Bighorn ranges in Wyoming, USA. Pika scat density was highest at mid-elevations and increased linearly with forage availability in both ranges. Scat density also increased with temperatures conducive to forage plant growth, and showed a unimodal relationship with the number of days below -5°C, which is modulated by insulating snowpack. Our results provide support for both the forage availability and winter snowpack hypotheses. Especially in montane systems, considering the context-dependent nature of climate effects across regions and elevations as well as interactions between climatic and other critical habitat characteristics, will be essential for predicting future species distributions.

  17. Climate Tolerances and Habitat Requirements Jointly Shape the Elevational Distribution of the American Pika (Ochotona princeps), with Implications for Climate Change Effects.

    PubMed

    Yandow, Leah H; Chalfoun, Anna D; Doak, Daniel F

    2015-01-01

    Some of the most compelling examples of ecological responses to climate change are elevational range shifts of individual species, which have been observed throughout the world. A growing body of evidence, however, suggests substantial mediation of simple range shifts due to climate change by other limiting factors. Understanding limiting factors for a species within different contexts, therefore, is critical for predicting responses to climate change. The American pika (Ochotona princeps) is an ideal species for investigating distributions in relation to climate because of their unusual and well-understood natural history as well as observed shifts to higher elevation in parts of their range. We tested three hypotheses for the climatic or habitat characteristics that may limit pika presence and abundance: summer heat, winter snowpack, and forage availability. We performed these tests using an index of pika abundance gathered in a region where environmental influences on pika distribution have not been well-characterized. We estimated relative pika abundance via scat surveys and quantified climatic and habitat characteristics across two North-Central Rocky Mountain Ranges, the Wind River and Bighorn ranges in Wyoming, USA. Pika scat density was highest at mid-elevations and increased linearly with forage availability in both ranges. Scat density also increased with temperatures conducive to forage plant growth, and showed a unimodal relationship with the number of days below -5°C, which is modulated by insulating snowpack. Our results provide support for both the forage availability and winter snowpack hypotheses. Especially in montane systems, considering the context-dependent nature of climate effects across regions and elevations as well as interactions between climatic and other critical habitat characteristics, will be essential for predicting future species distributions. PMID:26244851

  18. Climate Tolerances and Habitat Requirements Jointly Shape the Elevational Distribution of the American Pika (Ochotona princeps), with Implications for Climate Change Effects

    PubMed Central

    Yandow, Leah H.; Chalfoun, Anna D.; Doak, Daniel F.

    2015-01-01

    Some of the most compelling examples of ecological responses to climate change are elevational range shifts of individual species, which have been observed throughout the world. A growing body of evidence, however, suggests substantial mediation of simple range shifts due to climate change by other limiting factors. Understanding limiting factors for a species within different contexts, therefore, is critical for predicting responses to climate change. The American pika (Ochotona princeps) is an ideal species for investigating distributions in relation to climate because of their unusual and well-understood natural history as well as observed shifts to higher elevation in parts of their range. We tested three hypotheses for the climatic or habitat characteristics that may limit pika presence and abundance: summer heat, winter snowpack, and forage availability. We performed these tests using an index of pika abundance gathered in a region where environmental influences on pika distribution have not been well-characterized. We estimated relative pika abundance via scat surveys and quantified climatic and habitat characteristics across two North-Central Rocky Mountain Ranges, the Wind River and Bighorn ranges in Wyoming, USA. Pika scat density was highest at mid-elevations and increased linearly with forage availability in both ranges. Scat density also increased with temperatures conducive to forage plant growth, and showed a unimodal relationship with the number of days below -5°C, which is modulated by insulating snowpack. Our results provide support for both the forage availability and winter snowpack hypotheses. Especially in montane systems, considering the context-dependent nature of climate effects across regions and elevations as well as interactions between climatic and other critical habitat characteristics, will be essential for predicting future species distributions. PMID:26244851

  19. Spatial Heterogeneity of Rana boylii Habitat: Quantification and Ecological Meaningfulness

    NASA Astrophysics Data System (ADS)

    Yarnell, S. M.

    2005-05-01

    Analysis of the heterogeneity of stream habitat and how biological communities respond to that complexity are fundamental components of ecosystem analysis that are often inadequately addressed in watershed assessments and restoration practices. Many aquatic species, such as the Foothill Yellow-legged Frog (Rana boylii), known to associate with certain physical habitats at various times throughout their lifecycle may require some degree of habitat complexity at a larger reach scale for a population to persist. Recent research in the field of landscape ecology has expanded the use of spatial heterogeneity indices to other fields of ecology as an objective method to quantify variability in habitat. Provided that indices are used in an appropriate context and are shown to be ecologically meaningful, they provide a potentially useful tool for quantifying the variability in riverine habitat for aquatic species such as R. boylii. This study evaluated whether stream reaches with a high heterogeneity of geomorphic features, as measured by several key spatial heterogeneity indices, correlated with a greater relative abundance of R. boylii. R. boylii habitat associations were quantified throughout a single season to obtain further insight into the local hydraulic and geomorphic conditions preferred by each lifestage. The two best predictors of habitat associations by lifestage were velocity and substrate size, two key characteristics of geomorphic units such as riffles and pools. The heterogeneity of geomorphic units was then quantified and measured at the reach scale using a variety of spatial indices. Indices of spatial composition, such as Shannon's Diversity Index, were found to correlate well with frog abundance, while indices of spatial configuration, such as Contagion, were not significant. These findings indicate R. boylii may select stream reaches with increased geomorphic complexity that potentially provide habitats suitable to each lifestage with multiple functions

  20. Establishing Minimum Flow Requirements Based on Benthic Vegetation: What are Some Issues Related to Identifying Quantity of Inflow and Tools Used to Quantify Ecosystem Response?

    NASA Astrophysics Data System (ADS)

    Hunt, M. J.; Nuttle, W. K.; Cosby, B. J.; Marshall, F. E.

    2005-05-01

    Establishing minimum flow requirements in aquatic ecosystems is one way to stipulate controls on water withdrawals in a watershed. The basis of the determination is to identify the amount of flow needed to sustain a threshold ecological function. To develop minimum flow criteria an understanding of ecological response in relation to flow is essential. Several steps are needed including: (1) identification of important resources and ecological functions, (2) compilation of available information, (3) determination of historical conditions, (4) establishment of technical relationships between inflow and resources, and (5) identification of numeric criteria that reflect the threshold at which resources are harmed. The process is interdisciplinary requiring the integration of hydrologic and ecologic principles with quantitative assessments. The tools used quantify the ecological response and key questions related to how the quantity of flow influences the ecosystem are examined by comparing minimum flow determination in two different aquatic systems in South Florida. Each system is characterized by substantial hydrologic alteration. The first, the Caloosahatchee River is a riverine system, located on the southwest coast of Florida. The second, the Everglades- Florida Bay ecotone, is a wetland mangrove ecosystem, located on the southern tip of the Florida peninsula. In both cases freshwater submerged aquatic vegetation (Vallisneria americana or Ruppia maritima), located in areas of the saltwater- freshwater interface has been identified as a basis for minimum flow criteria. The integration of field studies, laboratory studies, and literature review was required. From this information we developed ecological modeling tools to quantify and predict plant growth in response to varying environmental variables. Coupled with hydrologic modeling tools questions relating to the quantity and timing of flow and ecological consequences in relation to normal variability are addressed.

  1. Quantifying resilience

    USGS Publications Warehouse

    Allen, Craig R.; Angeler, David G.

    2016-01-01

    Several frameworks to operationalize resilience have been proposed. A decade ago, a special feature focused on quantifying resilience was published in the journal Ecosystems (Carpenter, Westley & Turner 2005). The approach there was towards identifying surrogates of resilience, but few of the papers proposed quantifiable metrics. Consequently, many ecological resilience frameworks remain vague and difficult to quantify, a problem that this special feature aims to address. However, considerable progress has been made during the last decade (e.g. Pope, Allen & Angeler 2014). Although some argue that resilience is best kept as an unquantifiable, vague concept (Quinlan et al. 2016), to be useful for managers, there must be concrete guidance regarding how and what to manage and how to measure success (Garmestani, Allen & Benson 2013; Spears et al. 2015). Ideas such as ‘resilience thinking’ have utility in helping stakeholders conceptualize their systems, but provide little guidance on how to make resilience useful for ecosystem management, other than suggesting an ambiguous, Goldilocks approach of being just right (e.g. diverse, but not too diverse; connected, but not too connected). Here, we clarify some prominent resilience terms and concepts, introduce and synthesize the papers in this special feature on quantifying resilience and identify core unanswered questions related to resilience.

  2. Comparison of methods for determining streamflow requirements for aquatic habitat protection at selected sites on the Assabet and Charles Rivers, Eastern Massachusetts, 2000-02

    USGS Publications Warehouse

    Parker, Gene W.; Armstrong, David S.; Richards, Todd A.

    2004-01-01

    Four methods used to determine streamflow requirements for habitat protection at nine critical riffle reaches in the Assabet River and Charles River Basins were compared. The methods include three standard setting techniques?R2Cross, Wetted Perimeter, and Tennant?and a diagnostic method, the Range of Variability Approach. One study reach is on the main stem of the Assabet River, four reaches are on tributaries to the Assabet River (Cold Harbor Brook, Danforth Brook, Fort Meadow Brook, and Elizabeth Brook), three are on the main stem of the Charles River, and one is on a tributary to the Charles River (Mine Brook). The strength of the R2Cross and Wetted-Perimeter methods is that they may be applied at ungaged locations whereas the Tennant method and the Range of Variability Approach require a period of streamflow record for analysis. Fish community assessments conducted at or near riffle sites in flowing reaches of the Assabet River and Charles River Basins were used to indicate ecological conditions. The fish communities in the main stem and tributary reaches of both the Assabet and Charles River Basins indicated degraded aquatic ecosystems. However, the degree of degradation differs between the two basins. The extreme predominance of tolerant, generalist species in the Charles River fish community demon-strates the cumulative impacts of flow, habitat, and water-chemistry degradation, combined with the effects of nearby impoundments and changing land use. The range of discharges for nine ungaged riffle reaches defined by the median R2Cross 3-of-3 criteria, R2Cross 2-of-3 criteria, and Wetted-Perimeter streamflow requirements, was 0.86 cubic foot per second per square mile, 0.18 cubic foot per second per square mile, and 0.23 cubic foot per second per square mile, respectively. Application of R2Cross and Wetted-Perimeter methods to sites with altered streamflows or at sites that are riffles only at low to moderate flows can result in a greater variability of

  3. Evaluation of Streamflow Requirements for Habitat Protection by Comparison to Streamflow Characteristics at Index Streamflow-Gaging Stations in Southern New England

    USGS Publications Warehouse

    Armstrong, David S.; Parker, Gene W.; Richards, Todd A.

    2003-01-01

    Streamflow characteristics and methods for determining streamflow requirements for habitat protection were investigated at 23 active index streamflow-gaging stations in southern New England. Fish communities sampled near index streamflow-gaging stations in Massachusetts have a high percentage of fish that require flowing-water habitats for some or all of their life cycle. The relatively unaltered flow condition at these sites was assumed to be one factor that has contributed to this condition. Monthly flow durations and low flow statistics were determined for the index streamflow-gaging stations for a 25-year period from 1976 to 2000. Annual hydrographs were prepared for each index station from median streamflows at the 50-percent monthly flow duration, normalized by drainage area. A median monthly flow of 1 ft3/s/mi2 was used to split hydrographs into a high-flow period (November?May), and a low-flow period (June?October). The hydrographs were used to classify index stations into groups with similar median monthly flow durations. Index stations were divided into four regional groups, roughly paralleling the coast, to characterize streamflows for November to May; and into two groups, on the basis of base-flow index and percentage of sand and gravel in the contributing area, for June to October. For the June to October period, for index stations with a high base-flow index and contributing areas greater than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.57, 0.49, and 0.46 ft3/s/mi2 for July, August, and September, respectively. For index stations with a low base-flow index and contributing areas less than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.34, 0.28, and 0.27 ft3/s/mi2 for July, August, and September, respectively. Streamflow variability between wet and dry years can be characterized by use of the

  4. A framework to integrate habitat monitoring and restoration with endangered insect recovery.

    PubMed

    Bried, Jason; Tear, Tim; Shirer, Rebecca; Zimmerman, Chris; Gifford, Neil; Campbell, Steve; O'Brien, Kathy

    2014-12-01

    Monitoring is essential to track the long-term recovery of endangered species. Greater emphasis on habitat monitoring is especially important for taxa whose populations may be difficult to quantify (e.g., insects) or when true recovery (delisting) requires continuous species-specific habitat management. In this paper, we outline and implement a standardized framework to facilitate the integration of habitat monitoring with species recovery efforts. The framework has five parts: (1) identify appropriate sample units, (2) select measurable indicators of habitat requirements, (3) determine rating categories for these indicators, (4) design and implement appropriate data collection protocols, and (5) synthesize the ratings into an overall measure of habitat potential. Following these steps, we developed a set of recovery criteria to estimate habitat potential and initially assess restoration activities in the context of recovering an endangered insect, the Karner blue butterfly (Lycaeides melissa samuelis). We recommend basing the habitat potential grading scheme on recovery plan criteria, the latest information on species biology, and working hypotheses as needed. The habitat-based assessment framework helps to identify which recovery areas and habitat patches are worth investing in and what type of site-specific restoration work is needed. We propose that the transparency and decision-making process in endangered insect recovery efforts could be improved through adaptive management that explicitly identifies and tracks progress toward habitat objectives and ultimate population recovery.

  5. A Framework to Integrate Habitat Monitoring and Restoration with Endangered Insect Recovery

    NASA Astrophysics Data System (ADS)

    Bried, Jason; Tear, Tim; Shirer, Rebecca; Zimmerman, Chris; Gifford, Neil; Campbell, Steve; O'Brien, Kathy

    2014-12-01

    Monitoring is essential to track the long-term recovery of endangered species. Greater emphasis on habitat monitoring is especially important for taxa whose populations may be difficult to quantify (e.g., insects) or when true recovery (delisting) requires continuous species-specific habitat management. In this paper, we outline and implement a standardized framework to facilitate the integration of habitat monitoring with species recovery efforts. The framework has five parts: (1) identify appropriate sample units, (2) select measurable indicators of habitat requirements, (3) determine rating categories for these indicators, (4) design and implement appropriate data collection protocols, and (5) synthesize the ratings into an overall measure of habitat potential. Following these steps, we developed a set of recovery criteria to estimate habitat potential and initially assess restoration activities in the context of recovering an endangered insect, the Karner blue butterfly ( Lycaeides melissa samuelis). We recommend basing the habitat potential grading scheme on recovery plan criteria, the latest information on species biology, and working hypotheses as needed. The habitat-based assessment framework helps to identify which recovery areas and habitat patches are worth investing in and what type of site-specific restoration work is needed. We propose that the transparency and decision-making process in endangered insect recovery efforts could be improved through adaptive management that explicitly identifies and tracks progress toward habitat objectives and ultimate population recovery.

  6. A framework to integrate habitat monitoring and restoration with endangered insect recovery.

    PubMed

    Bried, Jason; Tear, Tim; Shirer, Rebecca; Zimmerman, Chris; Gifford, Neil; Campbell, Steve; O'Brien, Kathy

    2014-12-01

    Monitoring is essential to track the long-term recovery of endangered species. Greater emphasis on habitat monitoring is especially important for taxa whose populations may be difficult to quantify (e.g., insects) or when true recovery (delisting) requires continuous species-specific habitat management. In this paper, we outline and implement a standardized framework to facilitate the integration of habitat monitoring with species recovery efforts. The framework has five parts: (1) identify appropriate sample units, (2) select measurable indicators of habitat requirements, (3) determine rating categories for these indicators, (4) design and implement appropriate data collection protocols, and (5) synthesize the ratings into an overall measure of habitat potential. Following these steps, we developed a set of recovery criteria to estimate habitat potential and initially assess restoration activities in the context of recovering an endangered insect, the Karner blue butterfly (Lycaeides melissa samuelis). We recommend basing the habitat potential grading scheme on recovery plan criteria, the latest information on species biology, and working hypotheses as needed. The habitat-based assessment framework helps to identify which recovery areas and habitat patches are worth investing in and what type of site-specific restoration work is needed. We propose that the transparency and decision-making process in endangered insect recovery efforts could be improved through adaptive management that explicitly identifies and tracks progress toward habitat objectives and ultimate population recovery. PMID:25108660

  7. Evaluation of generalized habitat criteria for assessing impacts of altered flow regimes on warmwater fishes

    USGS Publications Warehouse

    Bowen, Z.H.; Freeman, Mary C.; Bovee, K.D.

    1998-01-01

    Assessing potential effects of flow regulation on southeastern warmwater fish assemblages is problematic because of high species richness and our poor knowledge of habitat requirements for most species. A previous attempt to reduce the complexity of describing habitat requirements for diverse assemblages defined five 'key habitat' types based on quantitative descriptions of depth, velocity, substrate, and cover for assessing the effects of streamflow alteration on fish communities. Our study investigated relationships between availability and temporal stability of key habitats and fish abundances at regulated and unregulated sites in the Tallapoosa River system. Fish assemblage characteristics at seven sites were quantified based on 1,400 electrofishing samples collected during 1994 and 1995. Simulations were used to model availability and temporal stability of key habitats at regulated and unregulated sites, Associations between fish assemblages and availability or stability of key habitats were identified using correlation analysis. We found that hydropeaking dam operation reduced the average length of time that shallow-water habitats were stable during the spring and summer and also reduced year-to-year variation in the stability of shallow-water habitats compared to unregulated sites. Within-site comparisons of fish and habitat variables indicated that differences in fish abundances correlated with differences in the availability and temporal stability of shallow-water habitats. Additionally, groups of stream fishes defined by taxonomy or differences in orientation to the substrate and feeding mode responded similarly to changes in key habitat availability. These findings demonstrate that the temporal and spatial availability of key habitats could serve as a useful measure of the potential effects of flow alteration on lotic fish assemblages, and suggest that both short-term temporal stability of key habitats as well as annual variation in key habitat

  8. A habitat overlap analysis derived from maxent for tamarisk and the south-western willow flycatcher

    NASA Astrophysics Data System (ADS)

    York, Patricia; Evangelista, Paul; Kumar, Sunil; Graham, James; Flather, Curtis; Stohlgren, Thomas

    2011-06-01

    Biologic control of the introduced and invasive, woody plant tamarisk ( Tamarix spp, saltcedar) in south-western states is controversial because it affects habitat of the federally endangered South-western Willow Flycatcher ( Empidonax traillii extimus). These songbirds sometimes nest in tamarisk where floodplain-level invasion replaces native habitats. Biologic control, with the saltcedar leaf beetle ( Diorhabda elongate), began along the Virgin River, Utah, in 2006, enhancing the need for comprehensive understanding of the tamarisk-flycatcher relationship. We used maximum entropy (Maxent) modeling to separately quantify the current extent of dense tamarisk habitat (>50% cover) and the potential extent of habitat available for E. traillii extimus within the studied watersheds. We used transformations of 2008 Landsat Thematic Mapper images and a digital elevation model as environmental input variables. Maxent models performed well for the flycatcher and tamarisk with Area Under the ROC Curve (AUC) values of 0.960 and 0.982, respectively. Classification of thresholds and comparison of the two Maxent outputs indicated moderate spatial overlap between predicted suitable habitat for E. traillii extimus and predicted locations with dense tamarisk stands, where flycatcher habitat will potentially change flycatcher habitats. Dense tamarisk habitat comprised 500 km2 within the study area, of which 11.4% was also modeled as potential habitat for E. traillii extimus. Potential habitat modeled for the flycatcher constituted 190 km2, of which 30.7% also contained dense tamarisk habitat. Results showed that both native vegetation and dense tamarisk habitats exist in the study area and that most tamarisk infestations do not contain characteristics that satisfy the habitat requirements of E. traillii extimus. Based on this study, effective biologic control of Tamarix spp. may, in the short term, reduce suitable habitat available to E. traillii extimus, but also has the potential

  9. Quantifier Comprehension in Corticobasal Degeneration

    ERIC Educational Resources Information Center

    McMillan, Corey T.; Clark, Robin; Moore, Peachie; Grossman, Murray

    2006-01-01

    In this study, we investigated patients with focal neurodegenerative diseases to examine a formal linguistic distinction between classes of generalized quantifiers, like "some X" and "less than half of X." Our model of quantifier comprehension proposes that number knowledge is required to understand both first-order and higher-order quantifiers.…

  10. Quantifying contextuality.

    PubMed

    Grudka, A; Horodecki, K; Horodecki, M; Horodecki, P; Horodecki, R; Joshi, P; Kłobus, W; Wójcik, A

    2014-03-28

    Contextuality is central to both the foundations of quantum theory and to the novel information processing tasks. Despite some recent proposals, it still faces a fundamental problem: how to quantify its presence? In this work, we provide a universal framework for quantifying contextuality. We conduct two complementary approaches: (i) the bottom-up approach, where we introduce a communication game, which grasps the phenomenon of contextuality in a quantitative manner; (ii) the top-down approach, where we just postulate two measures, relative entropy of contextuality and contextuality cost, analogous to existent measures of nonlocality (a special case of contextuality). We then match the two approaches by showing that the measure emerging from the communication scenario turns out to be equal to the relative entropy of contextuality. Our framework allows for the quantitative, resource-type comparison of completely different games. We give analytical formulas for the proposed measures for some contextual systems, showing in particular that the Peres-Mermin game is by order of magnitude more contextual than that of Klyachko et al. Furthermore, we explore properties of these measures such as monotonicity or additivity. PMID:24724629

  11. Quantifying water requirements of riparian river red gum (Eucalyptus camaldulensis) in the Murray-Darling Basin, Australia: Implications for the management of environmental flows

    USGS Publications Warehouse

    Doody, Tanya M.; Colloff, Matthew J.; Davies, Micah; Koul, Vijay; Benyon, Richard G.; Nagler, Pamela L.

    2015-01-01

    Water resource development and drought have altered river flow regimes, increasing average flood return intervals across floodplains in the Murray-Darling Basin, Australia, causing health declines in riparian river red gum (Eucalyptus camaldulensis) forests and woodlands. Environmental flow allocations helped to alleviate water stress during the recent Millennium Drought (1997–2010), however, quantification of the flood frequency required to support healthy E. camaldulensis communities is still needed. We quantified water requirements of E. camaldulensis for two years across a flood gradient (trees inundated at frequencies of 1:2, 1:5 and 1:10 years) at Yanga National Park, New South Wales to help inform management decision-making and design of environmental flows. Sap flow, evaporative losses and soil moisture measurements were used to determine transpiration, evapotranspiration and plant-available soil water before and after flooding. A formula was developed using plant-available soil water post-flooding and average annual rainfall, to estimate maintenance time of soil water reserves in each flood frequency zone. Results indicated that soil water reserves could sustain 1:2 and 1:5 trees for 15 months and six years, respectively. Trees regulated their transpiration rates, allowing them to persist within their flood frequency zone, and showed reduction in active sapwood area and transpiration rates when flood frequencies exceeded 1:2 years. A leaf area index of 0.5 was identified as a potential threshold indicator of severe drought stress. Our results suggest environmental water managers may have greater flexibility to adaptively manage floodplains in order to sustain E. camaldulensis forests and woodlands than has been appreciated hitherto.

  12. Using Multiscale Spatial Models to Assess Potential Surrogate Habitat for an Imperiled Reptile

    PubMed Central

    Fill, Jennifer M.; Gibbons, J. Whitfield; Bennett, Stephen H.; Mousseau, Timothy A.

    2015-01-01

    In evaluating conservation and management options for species, practitioners might consider surrogate habitats at multiple scales when estimating available habitat or modeling species’ potential distributions based on suitable habitats, especially when native environments are rare. Species’ dependence on surrogates likely increases as optimal habitat is degraded and lost due to anthropogenic landscape change, and thus surrogate habitats may be vital for an imperiled species’ survival in highly modified landscapes. We used spatial habitat models to examine a potential surrogate habitat for an imperiled ambush predator (eastern diamondback rattlesnake, Crotalus adamanteus; EDB) at two scales. The EDB is an apex predator indigenous to imperiled longleaf pine ecosystems (Pinus palustris) of the southeastern United States. Loss of native open-canopy pine savannas and woodlands has been suggested as the principal cause of the species’ extensive decline. We examined EDB habitat selection in the Coastal Plain tidewater region to evaluate the role of marsh as a potential surrogate habitat and to further quantify the species’ habitat requirements at two scales: home range (HR) and within the home range (WHR). We studied EDBs using radiotelemetry and employed an information-theoretic approach and logistic regression to model habitat selection as use vs. availability. We failed to detect a positive association with marsh as a surrogate habitat at the HR scale; rather, EDBs exhibited significantly negative associations with all landscape patches except pine savanna. Within home range selection was characterized by a negative association with forest and a positive association with ground cover, which suggests that EDBs may use surrogate habitats of similar structure, including marsh, within their home ranges. While our HR analysis did not support tidal marsh as a surrogate habitat, marsh may still provide resources for EDBs at smaller scales. PMID:25915926

  13. Habitat models for land-use planning: assumptions and strategies for development

    USGS Publications Warehouse

    Farmer, Adrian H.; Armbruster, Michael J.; Terrell, James W.; Schroeder, Richard L.

    1982-01-01

    Wildlife managers have long recognized that management goals must be constrained by the availability and suitability of habitat. This recognition, combined with ever increasing land development pressures, has resulted in environmental legislation emphasizing systematic approaches to collection and analysis of habitat information. Wildlife planners have responded with a variety of approached to the development of models that quantify habitat requirements. The use of habitat models in wildlife management is certainly not a new concept. Early models attempted to relate habitat quality and quantity as defined by various life requisites (Trippensee 1948). Conceptually, these early approaches are identical to many contemporary efforts directed at modeling habitat. This paper has two objectives related to contemporary habitat modeling approaches. The first objective is to characterize the assumptions and limitations inherent to operational habitat models. Various approaches to habitat modeling, some of which will be discussed at this conference, are described in their own terminology-which tends to obscure the fact that they have common ideals and are subject to the same sets of limitations. The second objective of this paper is to describe a strategy for development of habitat models consistent with these potential limitations. There seems to be two divergent perspectives on operational habitat models. The first is an ideal perspective, which views operational habitat models with skepticism because the current state of habitat knowledge is limited. The second is a pragmatic perspective, which recognizes that available habitat information, no matter how incomplete, can be used to improve the credibility of a land-use decision. The strategy outlined in this paper is directed toward the latter perspective but may help to bridge the gap between the pragmatic and ideal.

  14. Status and Habitat Requirements of White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1988-1989 Annual Report.

    SciTech Connect

    Nigro, Anthony A. )

    1989-09-01

    We report on our progress from April 1988 through March 1989 on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam. Highlights of results of our work in the Dalles and Bonneville reservoirs are: using setlines, we caught 1,586 sturgeon in The Dalles Reservoir and 484 sturgeon in Bonneville Reservoir in 1988. Fork length of fish caught ranged from 34 cm to 274 cm. Of the fish caught we marked 1,248 in The Dalles Reservoir and 341 in Bonneville Reservoir. Of the fish marked in 1988, we recaptured 82 in The Dalles Reservoir and none in Bonneville Reservoir. We recaptured 89 fish marked in 1987 in The Dalles Reservoir. Anglers recaptured 35 fish marked in 1988 and 16 fish marked in 1987 in The Dalles Reservoir. Anglers recaptured 2 sturgeon marked in 1988 in Bonneville Reservoir. Individual papers were processed separately for the data base.

  15. Catalysis: Quantifying charge transfer

    NASA Astrophysics Data System (ADS)

    James, Trevor E.; Campbell, Charles T.

    2016-02-01

    Improving the design of catalytic materials for clean energy production requires a better understanding of their electronic properties, which remains experimentally challenging. Researchers now quantify the number of electrons transferred from metal nanoparticles to an oxide support as a function of particle size.

  16. Habitat automation

    NASA Technical Reports Server (NTRS)

    Swab, Rodney E.

    1992-01-01

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

  17. Contrasting habitat selection amongst cephalopods in the Mediterranean Sea: When the environment makes the difference.

    PubMed

    Lauria, V; Garofalo, G; Gristina, M; Fiorentino, F

    2016-08-01

    Conservation of fish habitat requires a deeper knowledge of how species distribution patterns are related to environmental factors. Habitat suitability modelling is an essential tool to quantify species' realised niches and understand species-environment relationships. Cephalopods are important players in the marine food web and a significant resource for fisheries; they are also very sensitive to environmental changes. Here a time series of fishery-independent data (1998-2011) was used to construct habitat suitability models and investigate the influence of environmental variables on four commercial cephalopods: Todaropsis eblanae, Illex coindetii, Eledone moschata and Eledone cirrhosa, in the central Mediterranean Sea. The main environmental predictors of cephalopod habitat suitability were depth, seafloor morphology, chlorophyll-a concentration, sea surface temperature and surface salinity. Predictive maps highlighted contrasting habitat selection amongst species. This study identifies areas where the important commercial species of cephalopods are concentrated and provides significant information for a future spatial based approach to fisheries management in the Mediterranean Sea.

  18. Lake Shore and Littoral Habitat Structure: Precision and biological Relevance of a Field Survey Method.

    EPA Science Inventory

    Until recently, lake physical habitat assessment has been an underemployed tool for assessing lake and reservoir ecological condition. We outline and evaluate a rapid field sampling and analytical approach for quantifying near-shore physical habitat. We quantified the repeatabil...

  19. Flow and habitat effects on juvenile fish abundance in natural and altered flow regimes

    USGS Publications Warehouse

    Freeman, Mary C.; Bowen, Z.H.; Bovee, K.D.; Irwin, E.R.

    2001-01-01

    Conserving biological resources native to large river systems increasingly depends on how flow-regulated segments of these rivers are managed. Improving management will require a better understanding of linkages between river biota and temporal variability of flow and instream habitat. However, few studies have quantified responses of native fish populations to multiyear (>2 yr) patterns of hydrologic or habitat variability in flow-regulated systems. To provide these data, we quantified young-of-year (YOY) fish abundance during four years in relation to hydrologic and habitat variability in two segments of the Tallapoosa River in the southeastern United States. One segment had an unregulated flow regime, whereas the other was flow-regulated by a peak-load generating hydropower dam. We sampled fishes annually and explored how continuously recorded flow data and physical habitat simulation models (PHABSIM) for spring (April-June) and summer (July-August) preceding each sample explained fish abundances. Patterns of YOY abundance in relation to habitat availability (median area) and habitat persistence (longest period with habitat area continuously above the long-term median area) differed between unregulated and flow-regulated sites. At the unregulated site, YOY abundances were most frequently correlated with availability of shallow-slow habitat in summer (10 species) and persistence of shallow-slow and shallow-fast habitat in spring (nine species). Additionally, abundances were negatively correlated with 1-h maximum flow in summer (five species). At the flow-regulated site, YOY abundances were more frequently correlated with persistence of shallow-water habitats (four species in spring; six species in summer) than with habitat availability or magnitude of flow extremes. The associations of YOY with habitat persistence at the flow-regulated site corresponded to the effects of flow regulation on habitat patterns. Flow regulation reduced median flows during spring and

  20. The Influence of Relative Sediment Supply on Riverine Habitat Heterogeneity

    NASA Astrophysics Data System (ADS)

    Yarnell, S. M.

    2005-05-01

    The diversity of aquatic habitats in a stream reach and associated biological response are linked to physical processes that act at various spatial and time scales within a watershed. A fundamental driver of stream geomorphology integrating multi-scale processes is the relationship between sediment supply and transport capacity. This study explored the interactions between riverine habitat heterogeneity and the geomorphic processes governing channel conditions by testing the hypothesis that maximum habitat heterogeneity occurs in stream reaches with a moderate relative local sediment supply, as measured by the supply-capacity ratio. Habitat heterogeneity was quantified with an ecologically meaningful spatial heterogeneity index from the field of landscape ecology, Shannon's Diversity Index (SHDI), and relative sediment supply was quantified using a dimensionless bedload transport rate, q*. Data from previously published studies and a new field study on tributaries to the South Yuba River in Nevada County, California were evaluated to test the hypothesis. Results showed that in alluvial reaches where flow and sediment interacted freely without obstruction, moderate q* values correlated with high SHDI values; however, in reaches where less mobile structural elements, such as large woody debris and boulders, were present, SHDI increased as the percentage of structural elements increased. The results indicate two potential mechanisms for how relative sediment supply may drive habitat diversity at the reach scale. When structural elements are not a large proportion of the reach landscape, the supply-capacity ratio dictates the range of sediment textures and geomorphic features observed such that channels with a moderate relative sediment supply exhibit high habitat heterogeneity supporting the study hypothesis. In contrast, when structural elements are relatively abundant, increased local scour and deposition creates a greater variety of geomorphic features and sorted

  1. Habitat Suitability Index Models: Largemouth bass

    USGS Publications Warehouse

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

    1982-01-01

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

  2. Habitat Suitability Index Models: Eastern meadowlark

    USGS Publications Warehouse

    Schroeder, Richard L.; Sousa, Patrick J.

    1982-01-01

    Habitat preferences of the eastern meadowlark (Sturnella magna) are described in this publication, which is one of a series of Habitat Suitability Index (HSI) models. Habitat use information is presented in a synthesis of the literature on the species-habitat requirements of the eastern meadowlark, followed by the development of the HSI model. The model is presented in three formats: graphic, word, and mathematical, and is designed to provide information for use in impact assessment and habitat management activities.

  3. Habitat Suitability Index Models: Pine warbler

    USGS Publications Warehouse

    Schroeder, Richard L.

    1982-01-01

    Habitat preferences of the pine warbler (Dendroica pinus) are described in this publication, which is one of a series of Habitat Suitability Index (HSI) models. Habitat use information is presented in a synthesis of the literature on the species-habitat requirements of the pine warbler, followed by the development of the HSI model. The model is presented in three formats: graphic, word, and mathematical, and is designed to provide information for use in impact assessment and habitat management activities.

  4. Introduction to stream network habitat analysis

    USGS Publications Warehouse

    Bartholow, John M.; Waddle, Terry J.

    1986-01-01

    Increasing demands on stream resources by a variety of users have resulted in an increased emphasis on studies that evaluate the cumulative effects of basinwide water management programs. Network habitat analysis refers to the evaluation of an entire river basin (or network) by predicting its habitat response to alternative management regimes. The analysis principally focuses on the biological and hydrological components of the riv er basin, which include both micro- and macrohabitat. (The terms micro- and macrohabitat are further defined and discussed later in this document.) Both conceptual and analytic models are frequently used for simplifying and integrating the various components of the basin. The model predictions can be used in developing management recommendations to preserve, restore, or enhance instream fish habitat. A network habitat analysis should begin with a clear and concise statement of the study objectives and a thorough understanding of the institutional setting in which the study results will be applied. This includes the legal, social, and political considerations inherent in any water management setting. The institutional environment may dictate the focus and level of detail required of the study to a far greater extent than the technical considerations. After the study objectives, including species on interest, and institutional setting are collectively defined, the technical aspects should be scoped to determine the spatial and temporal requirements of the analysis. A macro level approach should be taken first to identify critical biological elements and requirements. Next, habitat availability is quantified much as in a "standard" river segment analysis, with the likely incorporation of some macrohabitat components, such as stream temperature. Individual river segments may be aggregated to represent the networkwide habitat response of alternative water management schemes. Things learned about problems caused or opportunities generated may

  5. The allometric relationship between resting metabolic rate and body mass in wild waterfowl (Anatidae) and an application to estimation of winter habitat requirements

    USGS Publications Warehouse

    Miller, M.R.; Eadie, J. McA

    2006-01-01

    We examined the allometric relationship between resting metabolic rate (RMR; kJ day-1) and body mass (kg) in wild waterfowl (Anatidae) by regressing RMR on body mass using species means from data obtained from published literature (18 sources, 54 measurements, 24 species; all data from captive birds). There was no significant difference among measurements from the rest (night; n = 37), active (day; n = 14), and unspecified (n = 3) phases of the daily cycle (P > 0.10), and we pooled these measurements for analysis. The resulting power function (aMassb) for all waterfowl (swans, geese, and ducks) had an exponent (b; slope of the regression) of 0.74, indistinguishable from that determined with commonly used general equations for nonpasserine birds (0.72-0.73). In contrast, the mass proportionality coefficient (b; y-intercept at mass = 1 kg) of 422 exceeded that obtained from the nonpasserine equations by 29%-37%. Analyses using independent contrasts correcting for phylogeny did not substantially alter the equation. Our results suggest the waterfowl equation provides a more appropriate estimate of RMR for bioenergetics analyses of waterfowl than do the general nonpasserine equations. When adjusted with a multiple to account for energy costs of free living, the waterfowl equation better estimates daily energy expenditure. Using this equation, we estimated that the extent of wetland habitat required to support wintering waterfowl populations could be 37%-50% higher than previously predicted using general nonpasserine equations. ?? The Cooper Ornithological Society 2006.

  6. Spatiotemporal dynamics of ecological variation of waterbird habitats in Dongtan area of Chongming Island

    NASA Astrophysics Data System (ADS)

    Fan, Xuezhong; Zhang, Liquan

    2012-05-01

    Based on Landsat TM images, we explored the pattern of variation of suitable waterbird habitats from 1990 to 2008 in the Dongtan area of Chongming Island at the Changjiang (Yangtze) River mouth. By applying our highly accurate indicator model ( R=0.999, P<0.01), we quantified the variations of fluctuation intensity for local waterbird habitats during 1990-2008, and for the main waterbird groups (Anatidae, Charadriidae, Ardeidae and Laridae) from 2006 to 2008, to evaluate the impact of habitat quantity change on the waterbird habitat status and the population dynamics of the different waterbird groups. The results show that the aquaculture ponds (AP) and the Scirpus mariqueter zone (SMZ) underwent drastic habitat changes during certain periods (AP: 1997-2000, 2000-2003, 2005-2008; SMZ: 1997-2000), and the fluctuation intensity differed among habitat types in the order AP>SMZ>TSH (total suitable habitat)>BSA (bare mud flat and shallow water area). The abandonment of tracts of aquaculture ponds in Dongtan in mid-2006 brought about an intensive population fluctuation, caused by rapidly changing habitat with the population expanding to adjacent areas. At present, Anatidae and Ardeidae are threatened in the Dongtan area with declining populations because of their very "picky" habitat requirements (i.e., high reliance on AP). The Charadriidae experienced enormous population declines in the late 1990s, however, they have since recovered to normal levels as habitat change has stabilized. Our findings suggest that the current challenges for habitat management are the protection and stabilization of AP and SMZ habitats.

  7. Assessing patterns of fish demographics and habitat in stream networks

    EPA Science Inventory

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

  8. Habitat suitability index models: Black crappie

    USGS Publications Warehouse

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

    1982-01-01

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

  9. Food technology in space habitats

    NASA Technical Reports Server (NTRS)

    Karel, M.

    1979-01-01

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

  10. Habitat Complexity Metrics to Guide Restoration of Large Rivers

    NASA Astrophysics Data System (ADS)

    Jacobson, R. B.; McElroy, B. J.; Elliott, C.; DeLonay, A.

    2011-12-01

    Restoration strategies on large, channelized rivers typically strive to recover lost habitat complexity, based on the assumption complexity and biophysical capacity are directly related. Although definition of links between complexity and biotic responses can be tenuous, complexity metrics have appeal because of their potential utility in quantifying habitat quality, defining reference conditions and design criteria, and measuring restoration progress. Hydroacoustic instruments provide many ways to measure complexity on large rivers, yet substantive questions remain about variables and scale of complexity that are meaningful to biota, and how complexity can be measured and monitored cost effectively. We explore these issues on the Missouri River, using the example of channel re-engineering projects that are intended to aid in recovery of the pallid sturgeon, an endangered benthic fish. We are refining understanding of what habitat complexity means for adult fish by combining hydroacoustic habitat assessments with acoustic telemetry to map locations during reproductive migrations and spawning. These data indicate that migrating sturgeon select points with relatively low velocity but adjacent to areas of high velocity (that is, with high velocity gradients); the integration of points defines pathways which minimize energy expenditures during upstream migrations of 10's to 100's of km. Complexity metrics that efficiently quantify migration potential at the reach scale are therefore directly relevant to channel restoration strategies. We are also exploring complexity as it relates to larval sturgeon dispersal. Larvae may drift for as many as 17 days (100's of km at mean velocities) before using up their yolk sac, after which they "settle" into habitats where they initiate feeding. An assumption underlying channel re-engineering is that additional channel complexity, specifically increased shallow, slow water, is necessary for early feeding and refugia. Development of

  11. Habitat model for the Florida Scrub Jay on John F. Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Breininger, David R.

    1992-01-01

    The Florida Scrub Jay is endemic to Florida. The John F. Kennedy Space Center (KSC) provides habitat for one of the three largest populations of the Florida Scrub Jay. This threatened bird occupies scrub, slash pine flatwoods, disturbed scrub, and coastal strand on KSC. Densities of Florida Scrub Jays were shown to vary with habitat characteristics but not necessarily with vegetation type. Relationships between Florida Scrub Jay densities and habitat characteristics were used to develop a habitat model to provide a tool to compare alternative sites for new facilities and to quantify environmental impacts. This model is being tested using long term demographic studies of colorbanded Florida Scrub Jays. Optimal habitat predicted by the model has greater than or equal to 50 percent of the shrub canopy comprised of scrub oaks, 20-50 percent open space or scrub oak vegetation within 100 m of a ruderal edge, less than or equal to 15 percent pine canopy cover, a shrub height of 120-170 cm, and is greater than or equal to 100 m from a forest. This document reviews life history, social behavior, food, foraging habitat, cover requirements, characteristics of habitat on KSC, and habitat preferences of the Florida Scrub Jay. Construction of the model and its limitations are discussed.

  12. The spatial structure of habitat selection: A caribou's-eye-view

    NASA Astrophysics Data System (ADS)

    Mayor, Stephen J.; Schaefer, James A.; Schneider, David C.; Mahoney, Shane P.

    2009-03-01

    Greater understanding of habitat selection requires investigation at the scales at which organisms perceive and respond to their environment. Such knowledge could reveal the relative importance of factors limiting populations and the extent of response to habitat changes, and so guide conservation initiatives. We conducted a novel, spatially explicit analysis of winter habitat selection by caribou ( Rangifer tarandus) in Newfoundland, Canada, to elucidate the spatial scales of habitat selection. We combined conventional hierarchical habitat analysis with a newly developed geospatial approach that quantifies selection across scales as the difference in variance between available and used sites. We used both ordination and univariate analyses of lichen and plant cover, snow hardness and depth. This represents the first use of ordination with geostatistics for the assessment of habitat selection. Caribou habitat selection was driven by shallow, soft snow and high cover of Cladina lichens and was strongest at feeding microsites (craters) and broader feeding areas. Habitat selection was most evident at distance lags of up to 15 km, perhaps an indication of the perceptual abilities of caribou.

  13. 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...

  14. 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

    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

    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

  15. Habitat Design Optimization and Analysis

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    Long-duration surface missions to the Moon and Mars will require habitats for the astronauts. The materials chosen for the habitat walls play a direct role in the protection against the harsh environments found on the surface. Choosing the best materials, their configuration, and the amount required is extremely difficult due to the immense size of the design region. Advanced optimization techniques are necessary for habitat wall design. Standard optimization techniques are not suitable for problems with such large search spaces; therefore, a habitat design optimization tool utilizing genetic algorithms has been developed. Genetic algorithms use a "survival of the fittest" philosophy, where the most fit individuals are more likely to survive and reproduce. This habitat design optimization tool is a multi-objective formulation of structural analysis, heat loss, radiation protection, and meteoroid protection. This paper presents the research and development of this tool.

  16. Stability of Caribbean coral communities quantified by long-term monitoring and autoregression models.

    PubMed

    Gross, Kevin; Edmunds, Peter J

    2015-07-01

    Tropical coral reefs exemplify ecosystems imperiled by environmental change. Anticipating the future of reef ecosystems requires understanding how scleractinian corals respond to the multiple environmental disturbances that threaten their survival. We analyzed the stability of coral reefs at three habitats at different depths along the south shore of St. John, U.S. Virgin Islands, using multivariate autoregression (MAR) models and two decades of monitoring data. We quantified several measures of ecosystem stability, including the magnitude of typical stochastic fluctuations, the rate of recovery following disturbance, and the sensitivity of coral cover to hurricanes and elevated sea temperature. Our results show that, even within a -4 km shore, coral communities in different habitats display different stability properties, and that the stability of each habitat corresponds with the habitat's known synecology. Two Orbicella-dominated habitats are less prone to annual stochastic fluctuations than coral communities in shallower water, but they recover slowly from disturbance, and one habitat has suffered recent losses in scleractinian cover that will not be quickly reversed. In contrast, a shallower, low-coral-cover habitat is subject to greater stochastic fluctuations, but rebounds more quickly from disturbance and is more robust to hurricanes and seawater warming. In some sense, the shallower community is more stable, although the stability arguably arises from having little coral cover left. Our results sharpen understanding of recent changes in coral communities at these habitats, provide a more detailed understanding of how these habitats may change in future environments, and illustrate how MAR models can be used to assess stability of communities founded upon long-lived species. PMID:26378304

  17. Stability of Caribbean coral communities quantified by long-term monitoring and autoregression models.

    PubMed

    Gross, Kevin; Edmunds, Peter J

    2015-07-01

    Tropical coral reefs exemplify ecosystems imperiled by environmental change. Anticipating the future of reef ecosystems requires understanding how scleractinian corals respond to the multiple environmental disturbances that threaten their survival. We analyzed the stability of coral reefs at three habitats at different depths along the south shore of St. John, U.S. Virgin Islands, using multivariate autoregression (MAR) models and two decades of monitoring data. We quantified several measures of ecosystem stability, including the magnitude of typical stochastic fluctuations, the rate of recovery following disturbance, and the sensitivity of coral cover to hurricanes and elevated sea temperature. Our results show that, even within a -4 km shore, coral communities in different habitats display different stability properties, and that the stability of each habitat corresponds with the habitat's known synecology. Two Orbicella-dominated habitats are less prone to annual stochastic fluctuations than coral communities in shallower water, but they recover slowly from disturbance, and one habitat has suffered recent losses in scleractinian cover that will not be quickly reversed. In contrast, a shallower, low-coral-cover habitat is subject to greater stochastic fluctuations, but rebounds more quickly from disturbance and is more robust to hurricanes and seawater warming. In some sense, the shallower community is more stable, although the stability arguably arises from having little coral cover left. Our results sharpen understanding of recent changes in coral communities at these habitats, provide a more detailed understanding of how these habitats may change in future environments, and illustrate how MAR models can be used to assess stability of communities founded upon long-lived species.

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

    PubMed

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

    2008-10-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

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

    USGS Publications Warehouse

    Lyons, J.E.

    2005-01-01

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

  1. Mars habitat

    NASA Technical Reports Server (NTRS)

    1991-01-01

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

  2. Habitat persistence for sedentary organisms in managed rivers: the case for the federally endangered dwarf wedgemussel (Alasmidonta heterodon) in the Delaware River

    USGS Publications Warehouse

    Maloney, Kelly O.; Lellis, William A.; Bennett, Randy M.; Waddle, Terry J.

    2012-01-01

    1. To manage the environmental flow requirements of sedentary taxa, such as mussels and aquatic insects with fixed retreats, we need a measure of habitat availability over a variety of flows (i.e. a measure of persistent habitat). Habitat suitability measures in current environmental flow assessments are measured on a ‘flow by flow’ basis and thus are not appropriate for these taxa. Here, we present a novel measure of persistent habitat suitability for the dwarf wedgemussel (Alasmidonta heterodon), listed as federally endangered in the U.S.A., in three reaches of the Delaware River. 2. We used a two-dimensional hydrodynamic model to quantify suitable habitat over a range of flows based on modelled depth, velocity, Froude number, shear velocity and shear stress at three scales (individual mussel, mussel bed and reach). Baseline potentially persistent habitat was quantified as the sum of pixels that met all thresholds identified for these variables for flows ≥40 m3 s−1, and we calculated the loss of persistently suitable habitat by sequentially summing suitable habitat estimates at lower flows. We estimated the proportion of mussel beds exposed at each flow and the amount of change in the size of the mussel bed for one reach. 3. For two reaches, mussel beds occupied areas with lower velocity, shear velocity, shear stress and Froude number than the reach average at all flows. In the third reach, this was true only at higher flows. Together, these results indicate that beds were possible refuge areas from the effects of these hydrological parameters. Two reaches showed an increase in the amount of exposed mussel beds with decreasing flow. 4. Baseline potentially persistent habitat was less than half the areal extent of potentially suitable habitat, and it decreased with decreasing flow. Actually identified beds and modelled persistent habitat showed good spatial overlap, but identified beds occupied only a portion of the total modelled persistent

  3. Physical habitat in the national wadeable streams assessment

    EPA Science Inventory

    Effective environmental policy decisions require stream habitat information that is accurate, precise, and relevant. The recent National Wadeable Streams Assessment (NWSA) carried out by the U.S. EPA required physical habitat information sufficiently comprehensive to facilitate i...

  4. Quantifying learning-dependent changes in the brain: Single-trial multivoxel pattern analysis requires slow event-related fMRI.

    PubMed

    Visser, Renée M; de Haan, Michelle I C; Beemsterboer, Tinka; Haver, Pia; Kindt, Merel; Scholte, H Steven

    2016-08-01

    Single-trial analysis is particularly useful for assessing cognitive processes that are intrinsically dynamic, such as learning. Studying these processes with fMRI is problematic, as the low signal-to-noise ratio of fMRI requires the averaging over multiple trials, obscuring trial-by-trial changes in neural activation. The superior sensitivity of multivoxel pattern analysis over univariate analyses has opened up new possibilities for single-trial analysis, but this may require different fMRI designs. Here, we measured fMRI and pupil dilation responses during discriminant aversive conditioning, to assess associative learning in a trial-by-trial manner. The impact of design choices was examined by varying trial spacing and trial order in a series of five experiments (total n = 66), while keeping stimulus duration constant (4.5 s). Our outcome measure was the change in similarity between neural response patterns related to two consecutive presentations of the same stimulus (within-stimulus) and between patterns related to pairs of different stimuli (between-stimulus) that shared a specific outcome (electric stimulation vs. no consequence). This trial-by-trial similarity analysis revealed clear single-trial learning curves in conditions with intermediate (8.1-12.6 s) and long (16.5-18.4 s) intervals, with effects being strongest in designs with long intervals and counterbalanced stimulus presentation. No learning curves were observed in designs with shorter intervals (1.6-6.1 s), indicating that rapid event-related designs-at present, the most common designs in fMRI research-are not suited for single-trial pattern analysis. These findings emphasize the importance of deciding on the type of analysis prior to data collection.

  5. The Habitat Connection.

    ERIC Educational Resources Information Center

    Naturescope, 1987

    1987-01-01

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

  6. Habitat Demonstration Unit - Deep Space Habitat Configuration

    NASA Video Gallery

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

  7. Habitat characteristics at marten subnivean access sites

    USGS Publications Warehouse

    Corn, Janelle G.; Raphael, Martin G.

    1992-01-01

    The occurrence of coarse woody debris (CWD) at sites of subnivean (under snow) access by martens (Martes americana) has not been quantified adequately, and must be better understood to provide suitable winter habitat management for the species. Consequently, we studied subnivean activity of martens in a subalpine forest in southern Wyoming to determine how subnivean space was accessed, and to examine microhabitat characteristics around entry sites. Martens used existing openings in snow, created primarily by logs at low snow depths and by small live spruce and fir trees at greater snow depths. Sites of marten subnivean entry had greater percent cover (P ≤ 0.01) and total volume of CWD (P ≤ 0.01), greater numbers of log layers (all P ≤ 0.02), greater volume of undecayed (P ≤ 0.05) and moderately decayed logs (P ≤ 0.02), less volume of very decayed logs (P ≤ 0.001), and fewer small root masses (P ≤ 0.001) than surrounding forest stands. Provision of sufficient CWD in winter habitat of martens may require specific effort, particularly in managed forests of the central Rocky Mountains.

  8. Fuzzy modelling of Atlantic salmon physical habitat

    NASA Astrophysics Data System (ADS)

    St-Hilaire, André; Mocq, Julien; Cunjak, Richard

    2015-04-01

    Fish habitat models typically attempt to quantify the amount of available river habitat for a given fish species for various flow and hydraulic conditions. To achieve this, information on the preferred range of values of key physical habitat variables (e.g. water level, velocity, substrate diameter) for the targeted fishs pecies need to be modelled. In this context, we developed several habitat suitability indices sets for three Atlantic salmon life stages (young-of-the-year (YOY), parr, spawning adults) with the help of fuzzy logic modeling. Using the knowledge of twenty-seven experts, from both sides of the Atlantic Ocean, we defined fuzzy sets of four variables (depth, substrate size, velocity and Habitat Suitability Index, or HSI) and associated fuzzy rules. When applied to the Romaine River (Canada), median curves of standardized Weighted Usable Area (WUA) were calculated and a confidence interval was obtained by bootstrap resampling. Despite the large range of WUA covered by the expert WUA curves, confidence intervals were relatively narrow: an average width of 0.095 (on a scale of 0 to 1) for spawning habitat, 0.155 for parr rearing habitat and 0.160 for YOY rearing habitat. When considering an environmental flow value corresponding to 90% of the maximum reached by WUA curve, results seem acceptable for the Romaine River. Generally, this proposed fuzzy logic method seems suitable to model habitat availability for the three life stages, while also providing an estimate of uncertainty in salmon preferences.

  9. Habitat Selection and Post-Release Movement of Reintroduced Brown Treecreeper Individuals in Restored Temperate Woodland

    PubMed Central

    Bennett, Victoria A.; Doerr, Veronica A. J.; Doerr, Erik D.; Manning, Adrian D.; Lindenmayer, David B.; Yoon, Hwan-Jin

    2012-01-01

    It is essential to choose suitable habitat when reintroducing a species into its former range. Habitat quality may influence an individual’s dispersal decisions and also ultimately where they choose to settle. We examined whether variation in habitat quality (quantified by the level of ground vegetation cover and the installation of nest boxes) influenced the movement, habitat choice and survival of a reintroduced bird species. We experimentally reintroduced seven social groups (43 individuals) of the brown treecreeper (Climacteris picumnus) into two nature reserves in south-eastern Australia. We radio-tracked 18 brown treecreepers from release in November 2009 until February 2010. We observed extensive movements by individuals irrespective of the release environment or an individual’s gender. This indicated that individuals were capable of dispersing and actively selecting optimum habitat. This may alleviate pressure on wildlife planners to accurately select the most optimum release sites, so long as the species’ requirements are met. There was significant variation in movement between social groups, suggesting that social factors may be a more important influence on movement than habitat characteristics. We found a significant effect of ground vegetation cover on the likelihood of settlement by social groups, with high rates of settlement and survival in dry forests, rather than woodland (where the species typically resides), which has implications for the success of woodland restoration. However, overall the effects of variation in habitat quality were not as strong as we had expected, and resulted in some unpredicted effects such as low survival and settlement in woodland areas with medium levels of ground vegetation cover. The extensive movement by individuals and unforeseen effects of habitat characteristics make it difficult to predict the outcome of reintroductions, the movement behaviour and habitat selection of reintroduced individuals, particularly

  10. Quantifying landscape linkages among giant panda subpopulations in regional scale conservation.

    PubMed

    Qi, Dunwu; Hu, Yibo; Gu, Xiaodong; Yang, Xuyi; Yang, Guang; Wei, Fuwen

    2012-06-01

    Understanding habitat requirements and identifying landscape linkages are essential for the survival of isolated populations of endangered species. Currently, some of the giant panda populations are isolated, which threatens their long-term survival, particularly in the Xiaoxiangling mountains. In the present study, we quantified niche requirements and then identified potential linkages of giant panda subpopulations in the most isolated region, using ecological niche factor analysis and a least-cost path model. Giant pandas preferred habitat with conifer forest and gentle slopes (>20 to ≤30°). Based on spatial distribution of suitable habitat, linkages were identified for the Yele subpopulation to 4 other subpopulations (Liziping, Matou, Xinmin and Wanba). Their lengths ranged from 15 to 54 km. The accumulated cost ranged from 693 to 3166 and conifer forest covered over 31%. However, a variety of features (e.g. major roads, human settlements and large unforested areas) might act as barriers along the linkages for giant panda dispersal. Our analysis quantified giant panda subpopulation connectivity to ensure long-term survival.

  11. Quantifying landscape linkages among giant panda subpopulations in regional scale conservation.

    PubMed

    Qi, Dunwu; Hu, Yibo; Gu, Xiaodong; Yang, Xuyi; Yang, Guang; Wei, Fuwen

    2012-06-01

    Understanding habitat requirements and identifying landscape linkages are essential for the survival of isolated populations of endangered species. Currently, some of the giant panda populations are isolated, which threatens their long-term survival, particularly in the Xiaoxiangling mountains. In the present study, we quantified niche requirements and then identified potential linkages of giant panda subpopulations in the most isolated region, using ecological niche factor analysis and a least-cost path model. Giant pandas preferred habitat with conifer forest and gentle slopes (>20 to ≤30°). Based on spatial distribution of suitable habitat, linkages were identified for the Yele subpopulation to 4 other subpopulations (Liziping, Matou, Xinmin and Wanba). Their lengths ranged from 15 to 54 km. The accumulated cost ranged from 693 to 3166 and conifer forest covered over 31%. However, a variety of features (e.g. major roads, human settlements and large unforested areas) might act as barriers along the linkages for giant panda dispersal. Our analysis quantified giant panda subpopulation connectivity to ensure long-term survival. PMID:22691200

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

    NASA Technical Reports Server (NTRS)

    Simon, Matthew A.; Wilhite, Alan W.

    2013-01-01

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

  13. Habitat Suitability Index Models: Yellow-Headed Blackbird

    USGS Publications Warehouse

    Schroeder, Richard L.

    1982-01-01

    Habitat preferences of the yellow-headed blackbird (Xanthocephalus xanthocephalus) are described in this publication. It is one of a series of Habitat Suitability Index (HSI) models and was developed through an analysis of available infomration on the species-habitat requirements of the species. Habitat use information is presented in a review of the literature, followed by the development of an HSI model, designed for use in impact assessment and habitat management activities.

  14. Home range dynamics, habitat selection, and survival of Greater Roadrunners

    USGS Publications Warehouse

    Kelley, S.W.; Ransom, D.; Butcher, J.A.; Schulz, G.G.; Surber, B.W.; Pinchak, W.E.; Santamaria, C.A.; Hurtado, L.A.

    2011-01-01

    Greater Roadrunners (Geococcyx californianus) are common, poorly studied birds of arid and semi-arid ecosystems in the southwestern United States. Conservation of this avian predator requires a detailed understanding of their movements and spatial requirements that is currently lacking. From 2006 to 2009, we quantified home-range and core area sizes and overlap, habitat selection, and survival of roadrunners (N= 14 males and 20 females) in north-central Texas using radio-telemetry and fixed kernel estimators. Median home-range and core-area sizes were 90.4 ha and 19.2 ha for males and 80.1 ha and 16.7 ha for females, respectively. The size of home range and core areas did not differ significantly by either sex or season. Our home range estimates were twice as large (x??= 108.9 ha) as earlier published estimates based on visual observations (x??= 28-50 ha). Mean percent overlap was 38.4% for home ranges and 13.7% for core areas. Male roadrunners preferred mesquite woodland and mesquite savanna cover types, and avoided the grass-forb cover type. Female roadrunners preferred mesquite savanna and riparian woodland cover types, and avoided grass-forb habitat. Kaplan-Meier annual survival probabilities for females (0.452 ?? 0.118[SE]) were twice that estimated for males (0.210 ?? 0.108), but this difference was not significant. Mortality rates of male roadrunners were higher than those of females during the spring when males call from elevated perches, court females, and chase competing males. Current land use practices that target woody-shrub removal to enhance livestock forage production could be detrimental to roadrunner populations by reducing availability of mesquite woodland and mesquite savanna habitat required for nesting and roosting and increasing the amount of grass-forb habitat that roadrunners avoid. ??2011 The Authors. Journal of Field Ornithology ??2011 Association of Field Ornithologists.

  15. Geospatial interface and model for predicting potential seagrass habitat

    EPA Science Inventory

    Restoration of ecosystem services provided by seagrass habitats in estuaries requires a clear understanding of the modes of action of multiple interacting stressors including nutrients, climate change, coastal land-use change, and habitat modification. We have developed a geos...

  16. Natural Propagation and Habitat Improvement, Volume I, Oregon, Supplement A: Habitat Enhancement Evaluation of Fish and Wash Creeks, 1983 Annual Report.

    SciTech Connect

    Everest, Fred

    1984-04-01

    Habitat improvements for anadromous salmonids on Fish Creek in the upper Clackamas Basin were evaluated. The primary objectives of the evaluation effort include: (1) evaluate and quantify the changes in salmonid spawning and rearing habitat resulting from a variety of habitat improvements; (2) evaluate and quantify the changes in fish populations and biomass resulting from habitat improvements; and (3) evaluate the cost-effectiveness of habitat improvements developed with BPA and KV funds on Fish Creek. This report integrates data for the evaluation efforts collected in the Fish Creek Basin in 1982 and 1983. 3 references, 34 figures, 23 tables.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  18. Quantifying the Spatial Ecology of Wide-Ranging Marine Species in the Gulf of California: Implications for Marine Conservation Planning

    PubMed Central

    Anadón, José Daniel; D'Agrosa, Caterina; Gondor, Anne; Gerber, Leah R.

    2011-01-01

    There is growing interest in systematic establishment of marine protected area (MPA) networks and representative conservation sites. This movement toward networks of no-take zones requires that reserves are deliberately and adequately spaced for connectivity. Here, we test the network functionality of an ecoregional assessment configuration of marine conservation areas by evaluating the habitat protection and connectivity offered to wide-ranging fauna in the Gulf of California (GOC, Mexico). We first use expert opinion to identify representative species of wide-ranging fauna of the GOC. These include leopard grouper, hammerhead sharks, California brown pelicans and green sea turtles. Analyzing habitat models with both structural and functional connectivity indexes, our results indicate that the configuration includes large proportions of biologically important habitat for the four species considered (25–40%), particularly, the best quality habitats (46–57%). Our results also show that connectivity levels offered by the conservation area design for these four species may be similar to connectivity levels offered by the entire Gulf of California, thus indicating that connectivity offered by the areas may resemble natural connectivity. The selected focal species comprise different life histories among marine or marine-related vertebrates and are associated with those habitats holding the most biodiversity values (i.e. coastal habitats); our results thus suggest that the proposed configuration may function as a network for connectivity and may adequately represent the marine megafauna in the GOC, including the potential connectivity among habitat patches. This work highlights the range of approaches that can be used to quantify habitat protection and connectivity for wide-ranging marine species in marine reserve networks. PMID:22163013

  19. Quantifying the spatial ecology of wide-ranging marine species in the Gulf of California: implications for marine conservation planning.

    PubMed

    Anadón, José Daniel; D'Agrosa, Caterina; Gondor, Anne; Gerber, Leah R

    2011-01-01

    There is growing interest in systematic establishment of marine protected area (MPA) networks and representative conservation sites. This movement toward networks of no-take zones requires that reserves are deliberately and adequately spaced for connectivity. Here, we test the network functionality of an ecoregional assessment configuration of marine conservation areas by evaluating the habitat protection and connectivity offered to wide-ranging fauna in the Gulf of California (GOC, Mexico). We first use expert opinion to identify representative species of wide-ranging fauna of the GOC. These include leopard grouper, hammerhead sharks, California brown pelicans and green sea turtles. Analyzing habitat models with both structural and functional connectivity indexes, our results indicate that the configuration includes large proportions of biologically important habitat for the four species considered (25-40%), particularly, the best quality habitats (46-57%). Our results also show that connectivity levels offered by the conservation area design for these four species may be similar to connectivity levels offered by the entire Gulf of California, thus indicating that connectivity offered by the areas may resemble natural connectivity. The selected focal species comprise different life histories among marine or marine-related vertebrates and are associated with those habitats holding the most biodiversity values (i.e. coastal habitats); our results thus suggest that the proposed configuration may function as a network for connectivity and may adequately represent the marine megafauna in the GOC, including the potential connectivity among habitat patches. This work highlights the range of approaches that can be used to quantify habitat protection and connectivity for wide-ranging marine species in marine reserve networks. PMID:22163013

  20. Mars habitat

    NASA Technical Reports Server (NTRS)

    Ayers, Dale; Barnes, Timothy; Bryant, Woody; Chowdhury, Parveen; Dillard, Joe; Gardner, Vernadette; Gregory, George; Harmon, Cheryl; Harrell, Brock; Hilton, Sherrill

    1991-01-01

    The objective of this study is to develop a conceptual design for a permanently manned, self-sustaining Martian facility, to accommodate a crew of 20 people. The goal is to incorporate the major functions required for long term habitation in the isolation of a barren planet into a thriving ecosystem. These functions include living, working, service, and medical facilities as well as a green house. The main design task was to focus on the internal layout while investigating the appropriate structure, materials, and construction techniques. The general concept was to create a comfortable, safe living environment for the crew members for a stay of six to twelve months on Mars. Two different concepts were investigated, a modular assembly reusable structure (MARS) designated Lavapolis, and a prefabricated space frame structure called Hexamars. Both models take into account factors such as future expansion, radiation shielding, and ease of assembly.

  1. Loss and modification of habitat

    USGS Publications Warehouse

    Lemckert, Francis; Hecnar, Stephen; Pilliod, David S.; Wilkinson, John W.; Heatwole, Harold

    2012-01-01

    Amphibians live in a wide variety of habitats around the world, many of which have been modified or destroyed by human activities. Most species have unique life history characteristics adapted to specific climates, habitats (e.g., lentic, lotic, terrestrial, arboreal, fossorial, amphibious), and local conditions that provide suitable areas for reproduction, development and growth, shelter from environmental extremes, and predation, as well as connectivity to other populations or habitats. Although some species are entirely aquatic or terrestrial, most amphibians, as their name implies, lead a dual life and require a mosaic of habitats in both aquatic and terrestrial ecosystems. With over 6 billion people on Earth, most species are now persisting in habitats that have been directly or indirectly influenced by human activities. Some species have disappeared where their habitats have been completely destroyed, reduced, or rendered unsuitable. Habitat loss and degradation are widely considered by most researchers as the most important causes of amphibian population decline globally (Barinaga 1990; Wake and Morowitz 1991; Alford and Richards 1999). In this chapter, a background on the diverse habitat requirements of amphibians is provided, followed by a discussion of the effects of urbanization, agriculture, livestock grazing, timber production and harvesting, fire and hazardous fuel management, and roads on amphibians and their habitats. Also briefly discussed is the influence on amphibian habitats of natural disturbances, such as extreme weather events and climate change, given the potential for human activities to impact climate in the longer term. For amphibians in general, microhabitats are of greater importance than for other vertebrates. As ectotherms with a skin that is permeable to water and with naked gelatinous eggs, amphibians are physiologically constrained to be active during environmental conditions that provide appropriate body temperatures and adequate

  2. Habitats of North American sea ducks.

    USGS Publications Warehouse

    Derksen, Dirk V.; Petersen, Margaret R.; Savard, Jean-Pierre L.

    2015-01-01

    Breeding, molting, fall and spring staging, and wintering habitats of the sea duck tribe Mergini are described based on geographic locations and distribution in North America, geomorphology, vegetation and soil types, and fresh water and marine characteristics. The dynamics of habitats are discussed in light of natural and anthropogenic events that shape areas important to sea ducks. Strategies for sea duck habitat management are outlined and recommendations for international collaboration to preserve key terrestrial and aquatic habitats are advanced. We follow the definition of habitat advanced by Odum (1971), which is the place or space where an organism lives. Weller (1999) emphasized that habitats for waterbirds required presence of sufficient resources (i.e., food, water, cover, space) for maintenance during a portion of their annual cycle. Habitats exploited by North American sea ducks are diverse, widespread across the continent and adjacent marine waters and until recently, most were only superficially known. Even following a 15-year-long effort through the Sea Duck Joint Venture and U.S. and Canadian Endangered/Threatened Species programs to fund research focused on sea duck habitats there are still important gaps in our understanding of key elements required by some species during various life stages. Importantly, many significant habitats, especially staging and wintering sites, have been and continue to be destroyed or altered, largely as a result of anthropogenic effects. Our goal here is to develop a comprehensive summary of marine, freshwater, and terrestrial habitats and their characteristics by considering sea duck species with similar needs as groups (e.g., eiders) within the tribe Mergini. Additionally, this chapter will examine threats and changes to sea duck habitats from human-caused and natural events. Finally, we will evaluate conservation and management programs underway or available for maintenance and enhancement of habitats critical for

  3. Wireless quantified reflex device

    NASA Astrophysics Data System (ADS)

    Lemoyne, Robert Charles

    The deep tendon reflex is a fundamental aspect of a neurological examination. The two major parameters of the tendon reflex are response and latency, which are presently evaluated qualitatively during a neurological examination. The reflex loop is capable of providing insight for the status and therapy response of both upper and lower motor neuron syndromes. Attempts have been made to ascertain reflex response and latency, however these systems are relatively complex, resource intensive, with issues of consistent and reliable accuracy. The solution presented is a wireless quantified reflex device using tandem three dimensional wireless accelerometers to obtain response based on acceleration waveform amplitude and latency derived from temporal acceleration waveform disparity. Three specific aims have been established for the proposed wireless quantified reflex device: 1. Demonstrate the wireless quantified reflex device is reliably capable of ascertaining quantified reflex response and latency using a quantified input. 2. Evaluate the precision of the device using an artificial reflex system. 3.Conduct a longitudinal study respective of subjects with healthy patellar tendon reflexes, using the wireless quantified reflex evaluation device to obtain quantified reflex response and latency. Aim 1 has led to the steady evolution of the wireless quantified reflex device from a singular two dimensional wireless accelerometer capable of measuring reflex response to a tandem three dimensional wireless accelerometer capable of reliably measuring reflex response and latency. The hypothesis for aim 1 is that a reflex quantification device can be established for reliably measuring reflex response and latency for the patellar tendon reflex, comprised of an integrated system of wireless three dimensional MEMS accelerometers. Aim 2 further emphasized the reliability of the wireless quantified reflex device by evaluating an artificial reflex system. The hypothesis for aim 2 is that

  4. Habitat selection by juvenile Mojave Desert tortoises

    USGS Publications Warehouse

    Todd, Brian D; Halstead, Brian J.; Chiquoine, Lindsay P.; Peaden, J. Mark; Buhlmann, Kurt A.; Tuberville, Tracey D.; Nafus, Melia G.

    2016-01-01

    Growing pressure to develop public lands for renewable energy production places several protected species at increased risk of habitat loss. One example is the Mojave desert tortoise (Gopherus agassizii), a species often at the center of conflicts over public land development. For this species and others on public lands, a better understanding of their habitat needs can help minimize negative impacts and facilitate protection or restoration of habitat. We used radio-telemetry to track 46 neonate and juvenile tortoises in the Eastern Mojave Desert, California, USA, to quantify habitat at tortoise locations and paired random points to assess habitat selection. Tortoise locations near burrows were more likely to be under canopy cover and had greater coverage of perennial plants (especially creosote [Larrea tridentata]), more coverage by washes, a greater number of small-mammal burrows, and fewer white bursage (Ambrosia dumosa) than random points. Active tortoise locations away from burrows were closer to washes and perennial plants than were random points. Our results can help planners locate juvenile tortoises and avoid impacts to habitat critical for this life stage. Additionally, our results provide targets for habitat protection and restoration and suggest that diverse and abundant small-mammal populations and the availability of creosote bush are vital for juvenile desert tortoises in the Eastern Mojave Desert.

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  8. Missouri River Emergent Sandbar Habitat Monitoring Plan - A Conceptual Framework for Adaptive Management

    USGS Publications Warehouse

    Sherfy, Mark H.; Stucker, Jennifer H.; Anteau, Michael J.

    2009-01-01

    Habitat conditions are one of the most important factors determining distribution and productivity of least terns (Sternula antillarum) and piping plovers (Charadrius melodus) in the upper Missouri River system (Ziewitz and others, 1992; Kruse and others, 2002). Habitat conditions are known to change within and among seasons in response to variation in river flows, weather conditions, and management actions targeted at providing for the needs of terns and plovers. Although these principles are generally agreed upon, there is little empirical information available on the quantity and quality of tern and plover habitats in this system, particularly with reference to the major life history events that must be supported (egg laying, incubation, and brood rearing). Habitat requirements for these events are composed of two major categories: nesting and foraging habitat. In the case of piping plovers, these two requirements must occur on the same area because plover chicks are constrained to foraging near nesting sites prior to fledging (Knetter and others, 2002; Haffner, 2005). In contrast, least terns chicks are fed by the adults, allowing food procurement for broods to occur outside the immediate nesting area; however, food resources must be close enough to nesting locations to minimize foraging time. The complexity and dynamics of the upper Missouri River system introduce considerable uncertainty into how best to manage tern and plover habitats, and how best to evaluate the effectiveness of this management. An extensive program of habitat monitoring will be needed to address this complexity and support the management of least terns and piping plovers under the Missouri River Recovery Program. These needs are being addressed, in part, through a program of habitat creation and management targeted at improving quality and quantity of habitats for terns and plovers. Given the momentum of these projects and their associated costs, it is imperative that the capacity be

  9. ESTUARINE HABITAT RESTORATION

    SciTech Connect

    Thom, Ronald M.; Borde, Amy B.

    2015-09-01

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

  10. 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...

  11. Concepts for manned lunar habitats

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  12. Contrasting habitat selection amongst cephalopods in the Mediterranean Sea: When the environment makes the difference.

    PubMed

    Lauria, V; Garofalo, G; Gristina, M; Fiorentino, F

    2016-08-01

    Conservation of fish habitat requires a deeper knowledge of how species distribution patterns are related to environmental factors. Habitat suitability modelling is an essential tool to quantify species' realised niches and understand species-environment relationships. Cephalopods are important players in the marine food web and a significant resource for fisheries; they are also very sensitive to environmental changes. Here a time series of fishery-independent data (1998-2011) was used to construct habitat suitability models and investigate the influence of environmental variables on four commercial cephalopods: Todaropsis eblanae, Illex coindetii, Eledone moschata and Eledone cirrhosa, in the central Mediterranean Sea. The main environmental predictors of cephalopod habitat suitability were depth, seafloor morphology, chlorophyll-a concentration, sea surface temperature and surface salinity. Predictive maps highlighted contrasting habitat selection amongst species. This study identifies areas where the important commercial species of cephalopods are concentrated and provides significant information for a future spatial based approach to fisheries management in the Mediterranean Sea. PMID:27371813

  13. Assessing the Wildlife Habitat Value of New England Salt Marshes: I. Model and Application

    EPA Science Inventory

    We developed an assessment model to quantify the wildlife habitat value of New England salt marshes based on marsh characteristics and the presence of habitat types that influence habitat use by terrestrial wildlife. Applying the model to12 salt marshes located in Narragansett B...

  14. Urban Areas. Habitat Pac.

    ERIC Educational Resources Information Center

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

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

  15. Predicting spatial and temporal distribution of Indo-Pacific lionfish (Pterois volitans) in Biscayne Bay through habitat suitability modeling

    USGS Publications Warehouse

    Bernal, Nicholas A.; DeAngelis, Donald L.; Schofield, Pamela J.; Sullivan Sealey, Kathleen

    2014-01-01

    Invasive species may exhibit higher levels of growth and reproduction when environmental conditions are most suitable, and thus their effects on native fauna may be intensified. Understanding potential impacts of these species, especially in the nascent stages of a biological invasion, requires critical information concerning spatial and temporal distributions of habitat suitability. Using empirically supported environmental variables (e.g., temperature, salinity, dissolved oxygen, rugosity, and benthic substrate), our models predicted habitat suitability for the invasive lionfish (Pterois volitans) in Biscayne Bay, Florida. The use of Geographic Information Systems (GIS) as a platform for the modeling process allowed us to quantify correlations between temporal (seasonal) fluctuations in the above variables and the spatial distribution of five discrete habitat quality classes, whose ranges are supported by statistical deviations from the apparent best conditions described in prior studies. Analysis of the resulting models revealed little fluctuation in spatial extent of the five habitat classes on a monthly basis. Class 5, which represented the area with environmental variables closest to the best conditions for lionfish, occupied approximately one-third of Biscayne Bay, with subsequent habitats declining in area. A key finding from this study was that habitat suitability increased eastward from the coastline, where higher quality habitats were adjacent to the Atlantic Ocean and displayed marine levels of ambient water quality. Corroboration of the models with sightings from the USGS-NAS database appeared to support our findings by nesting 79 % of values within habitat class 5; however, field testing (i.e., lionfish surveys) is necessary to confirm the relationship between habitat classes and lionfish distribution.

  16. Umatilla River Basin Anadromous Fish Habitat Enhancement Project : 1993 Annual Report.

    SciTech Connect

    Shaw, R. Todd

    1993-04-01

    The Umatilla Basin Anadromous Fish Habitat Enhancement Project is funded under the Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program Measure 704 (d) (1) 34.02 and targets the improvement of water quality and restoration of riparian areas, holding, spawning and rearing habitats of steelhead, spring and fall chinook and coho salmon. The project focused on implementing instream and riparian habitat improvements on private lands on the Umatilla Indian Reservation (hereafter referred to as Reservation) from April 1, 1988 to March 31, 1992. These efforts resulted in enhancement of the lower 1/4 mile of Boston Canyon Creek, the lower 4 river miles of Meacham Creek and 3.2 river miles of the Umatilla River (downstream of the Meacham Creek confluence upstream to the Reservation East Boundary). In 1993, the project shifted emphasis to a comprehensive watershed approach consistent with other basin efforts and began to identify upland and riparian watershed-wide causative factors impacting fisheries habitat and natural fisheries production capabilities throughout the Umatilla River Watershed. Maintenance of existing habitat improvement projects was included under this comprehensive approach. Maintenance of existing gravel traps, instream and bank stabilization structures was required within project areas during the reporting period due to spring flooding damage and high bedload movement. Maintenance activities were completed between river mile (RM) 0.0 and RM 0.25 Boston Canyon Creek, between RM 0.0 and RM 4 Meacham Creek and between RM 78.5 and RM 79 Umatilla River. Habitat enhancement areas were seeded with native grass, legume, shrub and wildflower mixes and planted with willow cuttings to assist in floodplain recovery, stream channel stability and filtering of sediments during high flow periods. Water quality monitoring continued for temperature and turbidity throughout the upper Umatilla River Watershed. Survey of cross sections and photo

  17. The airspace is habitat

    USGS Publications Warehouse

    Diehl, Robert H.

    2013-01-01

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

  18. Greater shrub dominance alters breeding habitat and food resources for migratory songbirds in Alaskan arctic tundra.

    PubMed

    Boelman, Natalie T; Gough, Laura; Wingfield, John; Goetz, Scott; Asmus, Ashley; Chmura, Helen E; Krause, Jesse S; Perez, Jonathan H; Sweet, Shannan K; Guay, Kevin C

    2015-04-01

    Climate warming is affecting the Arctic in multiple ways, including via increased dominance of deciduous shrubs. Although many studies have focused on how this vegetation shift is altering nutrient cycling and energy balance, few have explicitly considered effects on tundra fauna, such as the millions of migratory songbirds that breed in northern regions every year. To understand how increasing deciduous shrub dominance may alter breeding songbird habitat, we quantified vegetation and arthropod community characteristics in both graminoid and shrub dominated tundra. We combined measurements of preferred nest site characteristics for Lapland longspurs (Calcarius lapponicus) and Gambel's White-crowned sparrows (Zonotrichia leucophrys gambelii) with modeled predictions for the distribution of plant community types in the Alaskan arctic foothills region for the year 2050. Lapland longspur nests were found in sedge-dominated tussock tundra where shrub height does not exceed 20 cm, whereas White-crowned sparrows nested only under shrubs between 20 cm and 1 m in height, with no preference for shrub species. Shrub canopies had higher canopy-dwelling arthropod availability (i.e. small flies and spiders) but lower ground-dwelling arthropod availability (i.e. large spiders and beetles). Since flies are the birds' preferred prey, increasing shrubs may result in a net enhancement in preferred prey availability. Acknowledging the coarse resolution of existing tundra vegetation models, we predict that by 2050 there will be a northward shift in current White-crowned sparrow habitat range and a 20-60% increase in their preferred habitat extent, while Lapland longspur habitat extent will be equivalently reduced. Our findings can be used to make first approximations of future habitat change for species with similar nesting requirements. However, we contend that as exemplified by this study's findings, existing tundra modeling tools cannot yet simulate the fine-scale habitat

  19. Greater shrub dominance alters breeding habitat and food resources for migratory songbirds in Alaskan arctic tundra.

    PubMed

    Boelman, Natalie T; Gough, Laura; Wingfield, John; Goetz, Scott; Asmus, Ashley; Chmura, Helen E; Krause, Jesse S; Perez, Jonathan H; Sweet, Shannan K; Guay, Kevin C

    2015-04-01

    Climate warming is affecting the Arctic in multiple ways, including via increased dominance of deciduous shrubs. Although many studies have focused on how this vegetation shift is altering nutrient cycling and energy balance, few have explicitly considered effects on tundra fauna, such as the millions of migratory songbirds that breed in northern regions every year. To understand how increasing deciduous shrub dominance may alter breeding songbird habitat, we quantified vegetation and arthropod community characteristics in both graminoid and shrub dominated tundra. We combined measurements of preferred nest site characteristics for Lapland longspurs (Calcarius lapponicus) and Gambel's White-crowned sparrows (Zonotrichia leucophrys gambelii) with modeled predictions for the distribution of plant community types in the Alaskan arctic foothills region for the year 2050. Lapland longspur nests were found in sedge-dominated tussock tundra where shrub height does not exceed 20 cm, whereas White-crowned sparrows nested only under shrubs between 20 cm and 1 m in height, with no preference for shrub species. Shrub canopies had higher canopy-dwelling arthropod availability (i.e. small flies and spiders) but lower ground-dwelling arthropod availability (i.e. large spiders and beetles). Since flies are the birds' preferred prey, increasing shrubs may result in a net enhancement in preferred prey availability. Acknowledging the coarse resolution of existing tundra vegetation models, we predict that by 2050 there will be a northward shift in current White-crowned sparrow habitat range and a 20-60% increase in their preferred habitat extent, while Lapland longspur habitat extent will be equivalently reduced. Our findings can be used to make first approximations of future habitat change for species with similar nesting requirements. However, we contend that as exemplified by this study's findings, existing tundra modeling tools cannot yet simulate the fine-scale habitat

  20. Habitat requirements of the seabird tick, Ixodes uriae (Acari: Ixodidae), from the Antarctic Peninsula in relation to water balance characteristics of eggs, nonfed and engorged stages.

    PubMed

    Benoit, J B; Yoder, J A; Lopez-Martinez, G; Elnitsky, M A; Lee, R E; Denlinger, D L

    2007-02-01

    The seabird tick Ixodes uriae is exposed to extreme environmental conditions during the off-host phase of its life cycle on the Antarctic Peninsula. To investigate how this tick resists desiccation, water requirements of each developmental stage were determined. Features of I. uriae water balance include a high percentage body water content, low dehydration tolerance limit, and a high water loss rate, which are characteristics that classify this tick as hydrophilic. Like other ticks, I. uriae relies on water vapor uptake as an unfed larva and enhanced water retention in the adult, while nymphs are intermediate and exploit both strategies. Stages that do not absorb water vapor, eggs, fed larvae and fed nymphs, rely on water conservation. Other noteworthy features include heat sensitivity that promotes water loss in eggs and unfed larvae, an inability to drink free water from droplets, and behavioral regulation of water loss by formation of clusters. We conclude that I. uriae is adapted for life in a moisture-rich environment, and this requirement is met by clustering in moist, hydrating, microhabitats under rocks and debris that contain moisture levels that are higher than the tick's critical equilibrium activity.

  1. Habitat characteristics of North American tortoises: chapter 9

    USGS Publications Warehouse

    Nussear, Kenneth E.; Tuberville, Tracey D.

    2014-01-01

    North American tortoises are distributed in semi-arid and temperate deserts and coastal regions of the southern United States and Mexico. The five species currently recognized each have specific habitat requirements, which they fulfill through their selection of, and interaction with unique habitat constituents. In this chapter we discuss the physiographic and geological associations, perennial and annual vegetation components, shelter sites, and climatic conditions associated with the species’ habitats, as well as the potential threats to their habitat.

  2. Quantifying Faculty Workloads.

    ERIC Educational Resources Information Center

    Archer, J. Andrew

    Teaching load depends on many variables, however most colleges define it strictly in terms of contact or credit hours. The failure to give weight to variables such as number of preparations, number of students served, committee and other noninstructional assignments is usually due to the lack of a formula that will quantify the effects of these…

  3. Nesting habitat and nest site selection by the bald eagle in Maryland. Final report

    SciTech Connect

    Mosher, J.A.; Andrew, J.M.

    1981-07-01

    Habitat at 70 bald eagle (Haliaeetus leucocephalus) nest sites was quantified and compared with evaluations at 139 random habitat plots located in the Chesapeake Bay region of Maryland. Bald eagles selected vegetationally open habitats near water and away from selected human activities relative to random habitat plots. Successful nest sites were located in denser forest stands farther from water and unoccupied structures than unsuccessful nest sites.

  4. Quantifying Fish Assemblages in Large, Offshore Marine Protected Areas: An Australian Case Study

    PubMed Central

    Hill, Nicole A.; Barrett, Neville; Lawrence, Emma; Hulls, Justin; Dambacher, Jeffrey M.; Nichol, Scott; Williams, Alan; Hayes, Keith R.

    2014-01-01

    As the number of marine protected areas (MPAs) increases globally, so does the need to assess if MPAs are meeting their management goals. Integral to this assessment is usually a long-term biological monitoring program, which can be difficult to develop for large and remote areas that have little available fine-scale habitat and biological data. This is the situation for many MPAs within the newly declared Australian Commonwealth Marine Reserve (CMR) network which covers approximately 3.1 million km2 of continental shelf, slope, and abyssal habitat, much of which is remote and difficult to access. A detailed inventory of the species, types of assemblages present and their spatial distribution within individual MPAs is required prior to developing monitoring programs to measure the impact of management strategies. Here we use a spatially-balanced survey design and non-extractive baited video observations to quantitatively document the fish assemblages within the continental shelf area (a multiple use zone, IUCN VI) of the Flinders Marine Reserve, within the Southeast marine region. We identified distinct demersal fish assemblages, quantified assemblage relationships with environmental gradients (primarily depth and habitat type), and described their spatial distribution across a variety of reef and sediment habitats. Baited videos recorded a range of species from multiple trophic levels, including species of commercial and recreational interest. The majority of species, whilst found commonly along the southern or south-eastern coasts of Australia, are endemic to Australia, highlighting the global significance of this region. Species richness was greater on habitats containing some reef and declined with increasing depth. The trophic breath of species in assemblages was also greater in shallow waters. We discuss the utility of our approach for establishing inventories when little prior knowledge is available and how such an approach may inform future monitoring

  5. Quantifying fish assemblages in large, offshore marine protected areas: an Australian case study.

    PubMed

    Hill, Nicole A; Barrett, Neville; Lawrence, Emma; Hulls, Justin; Dambacher, Jeffrey M; Nichol, Scott; Williams, Alan; Hayes, Keith R

    2014-01-01

    As the number of marine protected areas (MPAs) increases globally, so does the need to assess if MPAs are meeting their management goals. Integral to this assessment is usually a long-term biological monitoring program, which can be difficult to develop for large and remote areas that have little available fine-scale habitat and biological data. This is the situation for many MPAs within the newly declared Australian Commonwealth Marine Reserve (CMR) network which covers approximately 3.1 million km2 of continental shelf, slope, and abyssal habitat, much of which is remote and difficult to access. A detailed inventory of the species, types of assemblages present and their spatial distribution within individual MPAs is required prior to developing monitoring programs to measure the impact of management strategies. Here we use a spatially-balanced survey design and non-extractive baited video observations to quantitatively document the fish assemblages within the continental shelf area (a multiple use zone, IUCN VI) of the Flinders Marine Reserve, within the Southeast marine region. We identified distinct demersal fish assemblages, quantified assemblage relationships with environmental gradients (primarily depth and habitat type), and described their spatial distribution across a variety of reef and sediment habitats. Baited videos recorded a range of species from multiple trophic levels, including species of commercial and recreational interest. The majority of species, whilst found commonly along the southern or south-eastern coasts of Australia, are endemic to Australia, highlighting the global significance of this region. Species richness was greater on habitats containing some reef and declined with increasing depth. The trophic breath of species in assemblages was also greater in shallow waters. We discuss the utility of our approach for establishing inventories when little prior knowledge is available and how such an approach may inform future monitoring

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

    NASA Astrophysics Data System (ADS)

    Levin, Phillip S.; Stunz, Gregory W.

    2005-07-01

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

  7. Quantifying Ubiquitin Signaling

    PubMed Central

    Ordureau, Alban; Münch, Christian; Harper, J. Wade

    2015-01-01

    Ubiquitin (UB)-driven signaling systems permeate biology, and are often integrated with other types of post-translational modifications (PTMs), most notably phosphorylation. Flux through such pathways is typically dictated by the fractional stoichiometry of distinct regulatory modifications and protein assemblies as well as the spatial organization of pathway components. Yet, we rarely understand the dynamics and stoichiometry of rate-limiting intermediates along a reaction trajectory. Here, we review how quantitative proteomic tools and enrichment strategies are being used to quantify UB-dependent signaling systems, and to integrate UB signaling with regulatory phosphorylation events. A key regulatory feature of ubiquitylation is that the identity of UB chain linkage types can control downstream processes. We also describe how proteomic and enzymological tools can be used to identify and quantify UB chain synthesis and linkage preferences. The emergence of sophisticated quantitative proteomic approaches will set a new standard for elucidating biochemical mechanisms of UB-driven signaling systems. PMID:26000850

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

    PubMed Central

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

    2012-01-01

    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

  9. Landscape habitat diversity: An information theoretic measure

    SciTech Connect

    Loehle, C.; Wein, G.

    1994-06-01

    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.

  10. Linking habitat mosaics and connectivity in a coral reef seascape.

    PubMed

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

    2012-09-18

    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.

  11. Linking habitat mosaics and connectivity in a coral reef seascape

    PubMed Central

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

    2012-01-01

    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

  12. Surface Habitat Systems

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.

    2009-01-01

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

  13. Effects of Mitigative Measures on Productivity of White Sturgeon Populations in the Columbia River Downstream from McNary Dam; Determine Status and Habitat Requirements of White Sturgeon Populations in the Columbia and Snake Rivers Upstream from McNary Dam, 1995-1996 Annual Report.

    SciTech Connect

    Rien, Thomas A.; Beiningen, Kirk T.

    1997-07-01

    This project began in July 1986 and is a cooperative effort of federal, state, and tribal fisheries entities to determine (1) the status and habitat requirements, and (2) effects of mitigative measures on productivity of white sturgeon populations in the lower Colombia and Snake rivers.

  14. The conflicting role of matrix habitats as conduits and barriers for dispersal.

    PubMed

    Kuefler, Daniel; Hudgens, Brian; Haddad, Nick M; Morris, William F; Thurgate, Nicole

    2010-04-01

    Determining connectivity within complex landscapes is difficult if habitats that facilitate dispersal differ from habitats where animals normally are found or enter. We addressed the question of how landscape features affect dispersal by quantifying two critical aspects of animal movement behavior that determine dispersal rates across complex landscapes: conductivity of major habitat types and behavior at boundaries between habitat types. Our tests consisted of behavioral experiments and observational surveys of a wetland butterfly, Satyrodes appalachia. Displacement rates varied among habitats, with the longest moves and straightest paths leading to greater displacement rate in open habitat and shortest moves and most sinuous paths causing the slowest displacement rate in riparian forest habitat. We found a strong negative relationship between the probability of entering a habitat and the speed of moving through it. Recognizing this central conflict between entering and moving through habitat is important for assessing the connectivity of complex landscapes.

  15. Quantifying light pollution

    NASA Astrophysics Data System (ADS)

    Cinzano, P.; Falchi, F.

    2014-05-01

    In this paper we review new available indicators useful to quantify and monitor light pollution, defined as the alteration of the natural quantity of light in the night environment due to introduction of manmade light. With the introduction of recent radiative transfer methods for the computation of light pollution propagation, several new indicators become available. These indicators represent a primary step in light pollution quantification, beyond the bare evaluation of the night sky brightness, which is an observational effect integrated along the line of sight and thus lacking the three-dimensional information.

  16. Selecting habitat management strategies on refuges

    USGS Publications Warehouse

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

    1998-01-01

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

  17. Advanced Plant Habitat (APH)

    NASA Technical Reports Server (NTRS)

    Richards, Stephanie E. (Compiler); Levine, Howard G.; Reed, David W.

    2016-01-01

    The Advanced Plant Habitat (APH) hardware will be a large growth volume plant habitat, capable of hosting multigenerational studies, in which environmental variables (e.g., temperature, relative humidity, carbon dioxide level light intensity and spectral quality) can be tracked and controlled in support of whole plant physiological testing and Bio-regenerative Life Support System investigations.

  18. Schoolyard Habitat Project Guide.

    ERIC Educational Resources Information Center

    Mason, Rich

    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…

  19. Wildlife Habitat Evaluation Handbook.

    ERIC Educational Resources Information Center

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

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

  20. The Habitat Project

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2011-01-01

    The Habitat Project is a multiday, differentiated, interdisciplinary environmental science lesson that incorporates skill-building and motivational strategies to internalize ecosystem vocabulary. Middle school students research an animal, display its physical characteristics on a poster, build a three-dimensional habitat and present their work…

  1. No net loss of fish habitat: a review and analysis of habitat compensation in Canada.

    PubMed

    Harper, D J; Quigley, J T

    2005-09-01

    The achievement of No Net Loss (NNL) through habitat compensation has rarely been assessed in Canada. Files relating to 124 Fisheries Act Section 35(2) authorizations issued by Fisheries and Oceans Canada for the harmful alteration, disruption, and destruction of fish habitat (HADD) were collected and reviewed. Data extracted from these files were pooled and analyzed to provide an indication of the types of HADDs that have been authorized in Canada, what habitats have been affected, and what habitat management approaches have been used when compensating for HADDs and monitoring and ensuring the success of the compensation. Determinations regarding the effectiveness of habitat compensation in achieving NNL were made. Impacts to 419,562 m2 of fish habitat from the 124 authorized HADDs were offset by 1,020,388 m2 of compensatory habitat. Eighty percent of the authorizations had compensation ratios (compensation area:HADD area) of 2:1 or less, and 25% of the authorizations had a compensation ratio that was less than 1:1. In-channel and riparian habitat were the most frequently impacted habitats. Urban development and roads and highways resulted in the greatest areal loss of habitat. The compensation option that was most often selected was the creation of in-kind habitat. The mean duration of post-construction monitoring programs was 3.7 years. Determinations of NNL could only be made for 17 authorizations as a result of poor proponent compliance with monitoring requirements and the qualitative assessment procedures used by the monitoring programs. Adequate resources, proper training, and standardized approaches to data management and monitoring programs are required to ensure that the conservation goal of NNL can be achieved in Canada. PMID:16082569

  2. Relationship between nitrogen concentration, light, and Zostera marina habitat quality and survival in southeastern Massachusetts estuaries.

    PubMed

    Benson, Jennifer L; Schlezinger, David; Howes, Brian L

    2013-12-15

    The relationship of eelgrass survival and habitat quality to water column nitrogen level, phytoplankton biomass, particulate matter, bottom light intensity, and light attenuation was quantified at 70 sites within 19 Massachusetts estuaries through 4 growing seasons (2007-2009, 2011). Sites included a range of eelgrass habitat quality, from stable productive eelgrass beds, to degraded beds, to areas that have lost all eelgrass coverage. Survival of transplanted eelgrass culms was used as a bio-indicator of habitat quality. Habitat quality based upon both changes in stability of eelgrass coverage and transplant survival was positively related to light intensity and percent transmittance. Transplant survival was consistent with habitat designations based upon long-term changes in eelgrass coverage, with lowest light coinciding with areas that lost eelgrass in earlier decades. Bottom light declined in proportion to increases in total nitrogen levels, phytoplankton biomass, and water column particulates determined from long-term water quality data. Field surveys indicated that eelgrass survival required bottom light ≥100 μE/m(2)/s and healthy eelgrass existed where tidally-averaged total nitrogen was less than 0.34 mg/L, equivalent to a mid-ebb tide water-column total nitrogen of <0.37 mg/L. Traditional sampling of water column nitrogen at mid-ebb tide was found to slightly overestimate the average nitrogen level over a complete tidal cycle. However, since long-term, ebb-tide and tidally-averaged total nitrogen are correlated, it is possible to use the monitoring average to guide management until tidally-averaged TN becomes available. Nitrogen thresholds that support eelgrass communities provide a fundamental tool for managing this habitat and for selection of transplant sites aimed at accelerating restoration of this resource under increasing nitrogen loading of the coastal zone.

  3. Lunar Habitat Optimization Using Genetic Algorithms

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  4. Decadal-scale effects of benthic habitat and marine reserve protection on Philippine goatfish (F: Mullidae)

    NASA Astrophysics Data System (ADS)

    Russ, Garry R.; Bergseth, Brock J.; Rizzari, Justin R.; Alcala, Angel C.

    2015-09-01

    Reef fish populations can be affected by both fishing and changes in benthic habitat. Yet, partitioning these effects is often difficult, usually requiring an appropriate sampling design and long-term monitoring. Here we quantify, over a 30-yr period, the effects of benthic habitat change and no-take marine reserve (NTMR) protection on the density and species richness of a lightly harvested benthic-feeding reef fish family, the Mullidae (goatfish), at four Philippine islands. Boosted regression trees demonstrated that goatfish density and species richness had strong negative associations with hard coral cover and strong positive associations with cover of dead substratum. No-take marine reserve protection had no effect on the density or species richness of goatfish over 19 and 30 yr at Sumilon and Apo islands, respectively. However, environmental disturbances (e.g., typhoons, coral bleaching) that reduced hard coral cover subsequently led to increases in goatfish numbers for periods ranging from 2 to 8 yr. After initial increases due to benthic disturbance, goatfish populations decreased during coral recovery, occurring on timescales of 10-20 yr. This long-term, "natural experiment" demonstrated that changes to benthic habitat (bottom-up control) had a far greater effect on Philippine goatfish populations than protection from fishing (a top-down effect) in NTMRs. Given the strong positive response of goatfish populations to loss of live hard coral cover, this group of fishes may be a valuable indicator species for habitat degradation on coral reefs.

  5. Resource pulses in desert river habitats: productivity-biodiversity hotspots, or mirages?

    PubMed

    Free, Carissa L; Baxter, Greg S; Dickman, Christopher R; Leung, Luke K P

    2013-01-01

    Resource pulses in the world's hot deserts are driven largely by rainfall and are highly variable in both time and space. However, run-on areas and drainage lines in arid regions receive more water more often than adjacent habitats, and frequently sustain relatively high levels of primary productivity. These landscape features therefore may support higher biotic diversity than other habitats, and potentially act as refuges for desert vertebrates and other biota during droughts. We used the ephemeral Field River in the Simpson Desert, central Australia, as a case study to quantify how resources and habitat characteristics vary spatially and temporally along the riparian corridor. Levels of moisture and nutrients were greater in the clay-dominated soils of the riverine corridor than in the surrounding sand dunes, as were cover values of trees, annual grasses, other annual plants and litter; these resources and habitat features were also greater near the main catchment area than in the distal reaches where the river channel runs out into extensive dune fields. These observations confirm that the riverine corridor is more productive than the surrounding desert, and support the idea that it may act as a refuge or as a channel for the ingress of peri-desert species. However, the work also demonstrates that species diversity of invertebrates and plants is not higher within the river corridor; rather, it is driven by rainfall and the accompanying increase in annual plants following a rain event. Further research is required to identify the biota that depend upon these resource pulses.

  6. Detroit River habitat inventory

    USGS Publications Warehouse

    Manny, Bruce A.

    2003-01-01

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

  7. Transmission loss in manatee habitats.

    PubMed

    Miksis-Olds, Jennifer L; Miller, James H

    2006-10-01

    The Florida manatee is regularly exposed to high volumes of vessel traffic and other human-related noise because of its coastal distribution. Quantifying specific aspects of the manatee's acoustic environment will allow for a better understanding of how these animals respond to both natural and human-induced changes in their environment. Transmission loss measurements were made in 24 sampling sites that were chosen based on the frequency of manatee presence. The Monterey-Miami Parabolic Equation model was used to relate environmental parameters to transmission loss in two extremely shallow water environments: seagrass beds and dredged habitats. Model accuracy was verified by field tests at all modeled sites. Results indicated that high-use grassbeds have higher levels of transmission loss for frequencies above 2 kHz compared to low-use sites of equal food species composition and density. This also happens to be the range of most efficient sound propagation inside the grassbed habitat and includes the dominant frequencies of manatee vocalizations. The acoustic environment may play a more important role in manatee grassbed selection than seagrass coverage or species composition, as linear regression analysis showed no significant correlation between usage and either total grass coverage, individual species coverage, or aerial pattern. PMID:17069327

  8. On quantifying insect movements

    SciTech Connect

    Wiens, J.A.; Crist, T.O. ); Milne, B.T. )

    1993-08-01

    We elaborate on methods described by Turchin, Odendaal Rausher for quantifying insect movement pathways. We note the need to scale measurement resolution to the study insects and the questions being asked, and we discuss the use of surveying instrumentation for recording sequential positions of individuals on pathways. We itemize several measures that may be used to characterize movement pathways and illustrate these by comparisons among several Eleodes beetles occurring in shortgrass steppe. The fractal dimension of pathways may provide insights not available from absolute measures of pathway configuration. Finally, we describe a renormalization procedure that may be used to remove sequential interdependence among locations of moving individuals while preserving the basic attributes of the pathway.

  9. Partitioning mechanisms of predator interference in different habitats.

    PubMed

    Griffen, Blaine D; Byers, James E

    2006-01-01

    Prey are often consumed by multiple predator species. Predation rates on shared prey species measured in isolation often do not combine additively due to interference or facilitation among the predator species. Furthermore, the strength of predator interactions and resulting prey mortality may change with habitat type. We experimentally examined predation on amphipods in rock and algal habitats by two species of intertidal crabs, Hemigrapsus sanguineus (top predators) and Carcinus maenas (intermediate predators). Algae provided a safer habitat for amphipods when they were exposed to only a single predator species. When both predator species were present, mortality of amphipods was less than additive in both habitats. However, amphipod mortality was reduced more in rock than algal habitat because intermediate predators were less protected in rock habitat and were increasingly targeted by omnivorous top predators. We found that prey mortality in general was reduced by (1) altered foraging behavior of intermediate predators in the presence of top predators, (2) top predators switching to foraging on intermediate predators rather than shared prey, and (3) density reduction of intermediate predators. The relative importance of these three mechanisms was the same in both habitats; however, the magnitude of each was greater in rock habitat. Our study demonstrates that the strength of specific mechanisms of interference between top and intermediate predators can be quantified but cautions that these results may be habitat specific. PMID:16086166

  10. Partitioning mechanisms of predator interference in different habitats.

    PubMed

    Griffen, Blaine D; Byers, James E

    2006-01-01

    Prey are often consumed by multiple predator species. Predation rates on shared prey species measured in isolation often do not combine additively due to interference or facilitation among the predator species. Furthermore, the strength of predator interactions and resulting prey mortality may change with habitat type. We experimentally examined predation on amphipods in rock and algal habitats by two species of intertidal crabs, Hemigrapsus sanguineus (top predators) and Carcinus maenas (intermediate predators). Algae provided a safer habitat for amphipods when they were exposed to only a single predator species. When both predator species were present, mortality of amphipods was less than additive in both habitats. However, amphipod mortality was reduced more in rock than algal habitat because intermediate predators were less protected in rock habitat and were increasingly targeted by omnivorous top predators. We found that prey mortality in general was reduced by (1) altered foraging behavior of intermediate predators in the presence of top predators, (2) top predators switching to foraging on intermediate predators rather than shared prey, and (3) density reduction of intermediate predators. The relative importance of these three mechanisms was the same in both habitats; however, the magnitude of each was greater in rock habitat. Our study demonstrates that the strength of specific mechanisms of interference between top and intermediate predators can be quantified but cautions that these results may be habitat specific.

  11. Comparative habitat use in a juniper woodland bird community

    USGS Publications Warehouse

    Pavlacky, D.C.; Anderson, S.H.

    2004-01-01

    We compared vegetation structure used by 14 bird species during the 1998 and 1999 breeding seasons to determine what habitat features best accounted for habitat division and community organization in Utah juniper (Juniperus osteosperma) woodlands of southwestern Wyoming. Habitat use was quantified by measuring 24 habitat variables in 461 bird-centered quadrats, each 0.04 ha in size. Using discriminant function analysis, we differentiated between habitat used by 14 bird species along 3 habitat dimensions: (1) variation in shrub cover, overstory juniper cover, mature tree density, understory height, and decadent tree density; (2) a gradient composed of elevation and forb cover; and (3) variation in grass cover, tree height, seedling/sapling cover, and bare ground/rock cover. Of 14 species considered, 9 exhibited substantial habitat partitioning: Mourning Dove (Zenaida macroura), Bewick's Wren (Thryomanes bewickii), Blue-gray Gnatcatcher (Polioptila caerulea), Mountain Bluebird (Sialia currucoides), Plumbeous Vireo (Vireo plumbeus), Green-tailed Towhee (Pipilo chlorurus), Brewer's Sparrow (Spizella breweri), Dark-eyed Junco (Junco hyemalis), and Cassin's Finch (Carpodacus cassinii). Our results indicate juniper bird communities of southwestern Wyoming are organized along a 3-dimensional habitat gradient composed of woodland maturity, elevation, and juniper recruitment. Because juniper birds partition habitat along successional and altitudinal gradients, indiscriminate woodland clearing as well as continued fire suppression will alter species composition. Restoration efforts should ensure that all successional stages of juniper woodland are present on the landscape.

  12. Multi-scale Hydroacoustic Remote Sensing of Sturgeon and Their Habitats in A Large, Turbid River

    NASA Astrophysics Data System (ADS)

    Jacobson, R. B.; Delonay, A.; Vishy, C.; Elliott, C. M.; Reuter, J. M.; Chojnacki, K. A.

    2009-12-01

    Restoration and management of the Lower Missouri River (LMOR) to support recovery of the endangered pallid sturgeon (Scaphirhynchus albus) requires quantifying habitats used during all life stages in order to isolate specific habitats (if any) that present bottlenecks to reproduction and survival. All life stages of the pallid sturgeon take place in deep, turbid rivers where direct observation of habitat selection, movement, and behavior are impossible. Female pallid sturgeon reproduce only once every 3-5 years, but during a reproductive season they may migrate 10’s to 100’s of kilometers to spawn in patches of only several 100’s of square meters over a period of several hours. The broad ranges of spatial and temporal scales involved in understanding how particular life stages relate to their environment, as well as the technical challenges of working in a large river, dictate application of a multi-scale, remote-sensing approach. At the scale of the entire LMOR (1300 km), extensive hydroacoustic mapping using single-beam bathymetry, acoustic Doppler current profiling (ADCP), and substrate classification has been used to quantify the fundamental biophysical capacity of river segments in terms of frequency distributions of hydraulic variables. Coordinated telemetric tracking of reproductive fish provides an understanding of home range and habitat selection at reach to segment scales, over timeframes commensurate with 3-5 year reproductive cycles. Intensive reach-scale hydroacoustic mapping using multibeam bathymetry, ADCP, and high-resolution sidescan sonar, combined with intensive telemetric tracking, provide coincident measures of habitat availability and selection for upstream-migrating and spawning fish during reproductive seasons. These assessments measure habitat variables at sub-meter to bedform scales, commensurate with the scale at which fish occupy their habitat. For example, dual-frequency identification sonar (DIDSON) imagery indicates that during

  13. Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  14. Lunar/Mars Surface Habitat Mockups Project

    NASA Technical Reports Server (NTRS)

    Tri, Terry O.; Daues, Katherine R.

    2005-01-01

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

  15. Modeling effects of conservation grassland losses on amphibian habitat

    USGS Publications Warehouse

    Mushet, David M.; Neau, Jordan L.; Euliss, Ned H.

    2014-01-01

    Amphibians provide many ecosystem services valued by society. However, populations have declined globally with most declines linked to habitat change. Wetlands and surrounding terrestrial grasslands form habitat for amphibians in the North American Prairie Pothole Region (PPR). Wetland drainage and grassland conversion have destroyed or degraded much amphibian habitat in the PPR. However, conservation grasslands can provide alternate habitat. In the United States, the Conservation Reserve Program (CRP) is the largest program maintaining grasslands on agricultural lands. We used an ecosystem services model (InVEST) parameterized for the PPR to quantify amphibian habitat over a six-year period (2007–2012). We then quantified changes in availability of amphibian habitat under various land-cover scenarios representing incremental losses (10%, 25%, 50%, 75%, and 100%) of CRP grasslands from 2012 levels. The area of optimal amphibian habitat in the four PPR ecoregions modeled (i.e., Northern Glaciated Plains, Northwestern Glaciated Plains, Lake Agassiz Plain, Des Moines Lobe) declined by approximately 22%, from 3.8 million ha in 2007 to 2.9 million ha in 2012. These losses were driven by the conversion of CRP grasslands to croplands, primarily for corn and soybean production. Our modeling identified an additional 0.8 million ha (26%) of optimal amphibian habitat that would be lost if remaining CRP lands are returned to crop production. An economic climate favoring commodity production over conservation has resulted in substantial losses of amphibian habitat across the PPR that will likely continue into the future. Other regions of the world face similar challenges to maintaining amphibian habitats.

  16. Habitat Evaluation Procedures (HEP) Report; Beaver Lake, Technical Report 2005.

    SciTech Connect

    Entz, Ray

    2005-05-01

    On August 14, 2003, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the Beaver Lake property, an acquisition completed by the Kalispel Tribe of Indians in November 2002. Evaluation species and appropriate models include bald eagle, black-capped chickadee, Canada goose, mallard, muskrat, yellow warbler, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The Beaver Lake Project provides a total of 232.26 Habitat Units (HUs) for the species evaluated. Conifer forest habitat provides 136.58 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. Forested wetland habitat provides 20.02 HUs for bald eagle, black-caped chickadee, mallard, and white-tailed deer. Scrub-shrub wetland habitat provides 7.67 HUs for mallard, yellow warbler, and white-tailed deer. Grassland meadow provides 22.69 HUs for Canada goose and mallard. Emergent wetlands provide 35.04 HUs for Canada goose, mallard, and muskrat. Open water provided 10.26 HUs for Canada goose, mallard, and muskrat. The objective of using HEP at the Beaver Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  17. Habitat Evaluation Procedures (HEP) Report; Gamblin Lake, Technical Report 2005.

    SciTech Connect

    Entz, Ray

    2005-05-01

    On August 12, 2003, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the Gamblin Lake property, an acquisition completed by the Kalispel Tribe of Indians in December 2002. Evaluation species and appropriate models include bald eagle, black-capped chickadee, mallard, muskrat, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The Gamblin Lake Project provides a total of 273.28 Habitat Units (HUs) for the species evaluated. Conifer forest habitat provides 127.92 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. Forested wetland habitat provides 21.06 HUs for bald eagle, black-caped chickadee, mallard, and white-tailed deer. Wet meadow provides 78.05 HUs for Canada goose and mallard. Emergent wetland habitat provides 46.25 HUs for mallard, muskrat, and Canada goose. The objective of using HEP at the Gamblin Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  18. Resource selection by the California condor (Gymnogyps californianus) relative to terrestrial-based habitats and meteorological conditions.

    PubMed

    Rivers, James W; Johnson, J Matthew; Haig, Susan M; Schwarz, Carl J; Glendening, John W; Burnett, L Joseph; George, Daniel; Grantham, Jesse

    2014-01-01

    Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to

  19. Resource selection by the California condor (Gymnogyps californianus) relative to terrestrial-based habitats and meteorological conditions

    USGS Publications Warehouse

    Johnson, J. Matthew; Haig, Susan M.; Schwarz, Carl J.; Glendening, John W.; Burnett, L. Joseph; George, Daniel; Grantham, Jesse

    2014-01-01

    Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to

  20. Resource Selection by the California Condor (Gymnogyps californianus) Relative to Terrestrial-Based Habitats and Meteorological Conditions

    PubMed Central

    Rivers, James W.; Johnson, J. Matthew; Haig, Susan M.; Schwarz, Carl J.; Glendening, John W.; Burnett, L. Joseph; George, Daniel; Grantham, Jesse

    2014-01-01

    Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to

  1. Resource selection by the California condor (Gymnogyps californianus) relative to terrestrial-based habitats and meteorological conditions.

    PubMed

    Rivers, James W; Johnson, J Matthew; Haig, Susan M; Schwarz, Carl J; Glendening, John W; Burnett, L Joseph; George, Daniel; Grantham, Jesse

    2014-01-01

    Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to

  2. Habitat Suitability Index Models: Southern red-backed vole (western United States)

    USGS Publications Warehouse

    Allen, Arthur W.

    1983-01-01

    Habitat preferences of the southern red-backed vole (Clethrionomys gapperi) are described in this publication, which is one of a series of Habitat Suitability Index (HSI) models. A review and synthesis of the literature is followed by development of a model of the species-habitat requirements of the southern red-backed vole. Habitat suitability indexes are designed for use with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  3. Habitat Suitability Index Models: Southern Red-Backed Vole (Western United States)

    USGS Publications Warehouse

    Allen, Arthur W.

    1983-01-01

    Habitat preferences of the southern red-backed vole (Clethrionomys gapperi) are described in this publication, which is one of a series of Habitat Suitability Index (HSI) models. A review and synthesis of the literature is followed by development of a model of the species-habitat requirements of the southern red-backed vole. Habitat suitability indexes are designed for use with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  4. Quantifying the Adaptive Cycle.

    PubMed

    Angeler, David G; Allen, Craig R; Garmestani, Ahjond S; Gunderson, Lance H; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994-2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems. PMID:26716453

  5. Uncertainty quantified trait predictions

    NASA Astrophysics Data System (ADS)

    Fazayeli, Farideh; Kattge, Jens; Banerjee, Arindam; Schrodt, Franziska; Reich, Peter

    2015-04-01

    Functional traits of organisms are key to understanding and predicting biodiversity and ecological change, which motivates continuous collection of traits and their integration into global databases. Such composite trait matrices are inherently sparse, severely limiting their usefulness for further analyses. On the other hand, traits are characterized by the phylogenetic trait signal, trait-trait correlations and environmental constraints, all of which provide information that could be used to statistically fill gaps. We propose the application of probabilistic models which, for the first time, utilize all three characteristics to fill gaps in trait databases and predict trait values at larger spatial scales. For this purpose we introduce BHPMF, a hierarchical Bayesian extension of Probabilistic Matrix Factorization (PMF). PMF is a machine learning technique which exploits the correlation structure of sparse matrices to impute missing entries. BHPMF additionally utilizes the taxonomic hierarchy for trait prediction. Implemented in the context of a Gibbs Sampler MCMC approach BHPMF provides uncertainty estimates for each trait prediction. We present comprehensive experimental results on the problem of plant trait prediction using the largest database of plant traits, where BHPMF shows strong empirical performance in uncertainty quantified trait prediction, outperforming the state-of-the-art based on point estimates. Further, we show that BHPMF is more accurate when it is confident, whereas the error is high when the uncertainty is high.

  6. Quantifying the adaptive cycle

    USGS Publications Warehouse

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  7. Quantifying solvated electrons' delocalization.

    PubMed

    Janesko, Benjamin G; Scalmani, Giovanni; Frisch, Michael J

    2015-07-28

    Delocalized, solvated electrons are a topic of much recent interest. We apply the electron delocalization range EDR(r;u) (J. Chem. Phys., 2014, 141, 144104) to quantify the extent to which a solvated electron at point r in a calculated wavefunction delocalizes over distance u. Calculations on electrons in one-dimensional model cavities illustrate fundamental properties of the EDR. Mean-field calculations on hydrated electrons (H2O)n(-) show that the density-matrix-based EDR reproduces existing molecular-orbital-based measures of delocalization. Correlated calculations on hydrated electrons and electrons in lithium-ammonia clusters illustrates how electron correlation tends to move surface- and cavity-bound electrons onto the cluster or cavity surface. Applications to multiple solvated electrons in lithium-ammonia clusters provide a novel perspective on the interplay of delocalization and strong correlation central to lithium-ammonia solutions' concentration-dependent insulator-to-metal transition. The results motivate continued application of the EDR to simulations of delocalized electrons.

  8. Quantifying the Adaptive Cycle

    PubMed Central

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems. PMID:26716453

  9. Habitat suitability of the Carolina madtom, an imperiled, endemic stream fish

    USGS Publications Warehouse

    Midway, S.R.; Kwak, Thomas J.; Aday, D.D.

    2010-01-01

    The Carolina madtom Noturus furiosus is an imperiled stream ictalurid that is endemic to the Tar and Neuse River basins in North Carolina. The Carolina madtom is listed as a threatened species by the state of North Carolina, and whereas recent distribution surveys have found that the Tar River basin population occupies a range similar to its historical range, the Neuse River basin population has shown recent significant decline. Quantification of habitat requirements and availability is critical for effective management and subsequent survival of the species. We investigated six reaches (three in each basin) to (1) quantify Carolina madtom microhabitat use, availability, and suitability; (2) compare suitable microhabitat availability between the two basins; and (3) examine use of an instream artificial cover unit. Carolina madtoms were located and their habitat was quantified at four of the six survey reaches. They most frequently occupied shallow to moderate depths of swift moving water over a sand substrate and used cobble for cover. Univariate and principal components analyses both showed that Carolina madtom use of instream habitat was selective (i.e., nonrandom). Interbasin comparisons suggested that suitable microhabitats were more prevalent in the impacted Neuse River basin than in the Tar River basin. We suggest that other physical or biotic effects may be responsible for the decline in the Neuse River basin population. We designed instream artificial cover units that were occupied by Carolina madtoms (25% of the time) and occasionally by other organisms. Carolina madtom abundance among all areas treated with the artificial cover unit was statistically higher than that in the control areas, demonstrating use of artificial cover when available. Microhabitat characteristics of occupied artificial cover units closely resembled those of natural instream microhabitat used by Carolina madtoms; these units present an option for conservation and restoration if

  10. Quantifying the Thermal Fatigue of CPV Modules

    SciTech Connect

    Bosco, N.; Kurtz, S.

    2011-02-01

    A method is presented to quantify thermal fatigue in the CPV die-attach from meteorological data. A comparative; study between cities demonstrates a significant difference in the accumulated damage. These differences are most; sensitive to the number of larger (ΔT) thermal cycles experienced for a location. High frequency data (<1/min) may; be required to most accurately employ this method.

  11. Current practices in the identification of critical habitat for threatened species.

    PubMed

    Camaclang, Abbey E; Maron, Martine; Martin, Tara G; Possingham, Hugh P

    2015-04-01

    The term critical habitat is used to describe the subset of habitat that is essential to the survival and recovery of species. Some countries legally require that critical habitat of listed threatened and endangered species be identified and protected. However, there is little evidence to suggest that the identification of critical habitat has had much impact on species recovery. We hypothesized that this may be due at least partly to a mismatch between the intent of critical habitat identification, which is to protect sufficient habitat for species persistence and recovery, and its practice. We used content analysis to systematically review critical habitat documents from the United States, Canada, and Australia. In particular, we identified the major trends in type of information used to identify critical habitat and in occupancy of habitat identified as critical. Information about population viability was used to identify critical habitat for only 1% of the species reviewed, and for most species, designated critical habitat did not include unoccupied habitat. Without reference to population viability, it is difficult to determine how much of a species' occupied and unoccupied habitat will be required for persistence. We therefore conclude that the identification of critical habitat remains inconsistent with the goal of protecting sufficient habitat to support persistence and recovery of the species. Ensuring that critical habitat identification aligns more closely with its intent will improve the accuracy of the designations and may therefore help improve the benefits to species recovery when combined with adequate implementation and enforcement of legal protections. PMID:25472827

  12. Current practices in the identification of critical habitat for threatened species.

    PubMed

    Camaclang, Abbey E; Maron, Martine; Martin, Tara G; Possingham, Hugh P

    2015-04-01

    The term critical habitat is used to describe the subset of habitat that is essential to the survival and recovery of species. Some countries legally require that critical habitat of listed threatened and endangered species be identified and protected. However, there is little evidence to suggest that the identification of critical habitat has had much impact on species recovery. We hypothesized that this may be due at least partly to a mismatch between the intent of critical habitat identification, which is to protect sufficient habitat for species persistence and recovery, and its practice. We used content analysis to systematically review critical habitat documents from the United States, Canada, and Australia. In particular, we identified the major trends in type of information used to identify critical habitat and in occupancy of habitat identified as critical. Information about population viability was used to identify critical habitat for only 1% of the species reviewed, and for most species, designated critical habitat did not include unoccupied habitat. Without reference to population viability, it is difficult to determine how much of a species' occupied and unoccupied habitat will be required for persistence. We therefore conclude that the identification of critical habitat remains inconsistent with the goal of protecting sufficient habitat to support persistence and recovery of the species. Ensuring that critical habitat identification aligns more closely with its intent will improve the accuracy of the designations and may therefore help improve the benefits to species recovery when combined with adequate implementation and enforcement of legal protections.

  13. Modeling Protected Species Habitat and Assigning Risk to Inform Regulatory Decisions

    NASA Astrophysics Data System (ADS)

    Montgomery, Robert A.; Rubeck-Schurtz, C. Nichole; Millenbah, Kelly F.; Roloff, Gary J.; Whalon, Mark E.; Olsen, Larry G.

    2009-07-01

    In the United States, environmental regulatory agencies are required to use “best available” scientific information when making decisions on a variety of issues. However, agencies are often hindered by coarse or incomplete data, particularly as it pertains to threatened and endangered species protection. Stakeholders often agree that more resolute and integrated processes for decision-making are desirable. We demonstrate a process that uses species occurrence data for a federally endangered insect (Karner blue butterfly), a readily available habitat modeling tool, and spatially explicit information about an important Michigan commodity (tart cherries). This case study has characteristics of many protected species regulatory decisions in that species occurrence data were sparse and unequally distributed; regulatory decisions (on pesticide use) were required with potentially significant impacts on a viable agricultural industry; and stakeholder relations were diverse, misinformed, and, in some situations, unjustly contentious. Results from our process include a large-scale, empirically derived habitat suitability map for the focal species and a risk ranking of tart cherry orchards with risk based on the likelihood that pesticide applications will influence the focal protected species. Although the majority (77%) of pesticide-influence zones overlapped Karner blue butterfly habitat, risk scores associated with each orchard were low. Through our process we demonstrated that spatially explicit models can help stakeholders visualize and quantify potential protected species effects. In addition, model outputs can serve to guide field activities (e.g., species surveys and implementation of pesticide buffer zones) that help minimize future effects.

  14. Modeling protected species habitat and assigning risk to inform regulatory decisions.

    PubMed

    Montgomery, Robert A; Rubeck-Schurtz, C Nichole; Millenbah, Kelly F; Roloff, Gary J; Whalon, Mark E; Olsen, Larry G

    2009-07-01

    In the United States, environmental regulatory agencies are required to use "best available" scientific information when making decisions on a variety of issues. However, agencies are often hindered by coarse or incomplete data, particularly as it pertains to threatened and endangered species protection. Stakeholders often agree that more resolute and integrated processes for decision-making are desirable. We demonstrate a process that uses species occurrence data for a federally endangered insect (Karner blue butterfly), a readily available habitat modeling tool, and spatially explicit information about an important Michigan commodity (tart cherries). This case study has characteristics of many protected species regulatory decisions in that species occurrence data were sparse and unequally distributed; regulatory decisions (on pesticide use) were required with potentially significant impacts on a viable agricultural industry; and stakeholder relations were diverse, misinformed, and, in some situations, unjustly contentious. Results from our process include a large-scale, empirically derived habitat suitability map for the focal species and a risk ranking of tart cherry orchards with risk based on the likelihood that pesticide applications will influence the focal protected species. Although the majority (77%) of pesticide-influence zones overlapped Karner blue butterfly habitat, risk scores associated with each orchard were low. Through our process we demonstrated that spatially explicit models can help stakeholders visualize and quantify potential protected species effects. In addition, model outputs can serve to guide field activities (e.g., species surveys and implementation of pesticide buffer zones) that help minimize future effects.

  15. Quantifying Anderson's fault types

    USGS Publications Warehouse

    Simpson, R.W.

    1997-01-01

    Anderson [1905] explained three basic types of faulting (normal, strike-slip, and reverse) in terms of the shape of the causative stress tensor and its orientation relative to the Earth's surface. Quantitative parameters can be defined which contain information about both shape and orientation [Ce??le??rier, 1995], thereby offering a way to distinguish fault-type domains on plots of regional stress fields and to quantify, for example, the degree of normal-faulting tendencies within strike-slip domains. This paper offers a geometrically motivated generalization of Angelier's [1979, 1984, 1990] shape parameters ?? and ?? to new quantities named A?? and A??. In their simple forms, A?? varies from 0 to 1 for normal, 1 to 2 for strike-slip, and 2 to 3 for reverse faulting, and A?? ranges from 0?? to 60??, 60?? to 120??, and 120?? to 180??, respectively. After scaling, A?? and A?? agree to within 2% (or 1??), a difference of little practical significance, although A?? has smoother analytical properties. A formulation distinguishing horizontal axes as well as the vertical axis is also possible, yielding an A?? ranging from -3 to +3 and A?? from -180?? to +180??. The geometrically motivated derivation in three-dimensional stress space presented here may aid intuition and offers a natural link with traditional ways of plotting yield and failure criteria. Examples are given, based on models of Bird [1996] and Bird and Kong [1994], of the use of Anderson fault parameters A?? and A?? for visualizing tectonic regimes defined by regional stress fields. Copyright 1997 by the American Geophysical Union.

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

    USGS Publications Warehouse

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

    2006-01-01

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

  17. External Device to Incrementally Skid the Habitat (E-DISH)

    NASA Technical Reports Server (NTRS)

    Brazell, J. W.; Introne, Steve; Bedell, Lisa; Credle, Ben; Holp, Graham; Ly, Siao; Tait, Terry

    1994-01-01

    A Mars habitat transport system was designed as part of the NASA Mars exploration program. The transport system, the External Device to Incrementally Skid the Habitat (E - DISH), will be used to transport Mars habitats from their landing sites to the colony base and will be detached after unloading. The system requirements for Mars were calculated and scaled for model purposes. Specific model materials are commonly found and recommendations for materials for the Mars design are included.

  18. Simple measures of channel habitat complexity predict transient hydraulic storage in streams

    EPA Science Inventory

    Stream thalweg depth profiles (along path of greatest channel depth) and woody debris tallies have recently become components of routine field procedures for quantifying physical habitat in national stream monitoring efforts. Mean residual depth, standard deviation of thalweg dep...

  19. Physical habitat structure of the lake shoreline and littoral zone -- How important is it?

    EPA Science Inventory

    The recent National Lakes Assessment (NLA) included the first national assessment of littoral and lakeshore physical habitat. It quantified water depth, surface characteristics, bank morphology, lake level fluctuations, substrate, fish concealment features, aquatic macrophytes, l...

  20. Using multilevel models to quantify heterogeneity in resource selection

    USGS Publications Warehouse

    Wagner, T.; Diefenbach, D.R.; Christensen, S.A.; Norton, A.S.

    2011-01-01

    Models of resource selection are being used increasingly to predict or model the effects of management actions rather than simply quantifying habitat selection. Multilevel, or hierarchical, models are an increasingly popular method to analyze animal resource selection because they impose a relatively weak stochastic constraint to model heterogeneity in habitat use and also account for unequal sample sizes among individuals. However, few studies have used multilevel models to model coefficients as a function of predictors that may influence habitat use at different scales or quantify differences in resource selection among groups. We used an example with white-tailed deer (Odocoileus virginianus) to illustrate how to model resource use as a function of distance to road that varies among deer by road density at the home range scale. We found that deer avoidance of roads decreased as road density increased. Also, we used multilevel models with sika deer (Cervus nippon) and white-tailed deer to examine whether resource selection differed between species. We failed to detect differences in resource use between these two species and showed how information-theoretic and graphical measures can be used to assess how resource use may have differed. Multilevel models can improve our understanding of how resource selection varies among individuals and provides an objective, quantifiable approach to assess differences or changes in resource selection. ?? The Wildlife Society, 2011.

  1. A review of approaches for classifying benthic habitats and evaluating habitat quality.

    PubMed

    Diaz, Robert J; Solan, Martin; Valente, Raymond M

    2004-11-01

    We have assessed the current state of knowledge relative to methods used in assessing sub-tidal benthic habitat quality and the classification of benthic habitats. While our main focus is on marine habitat, we extensively draw on knowledge gained in freshwater systems where benthic assessment procedures are at an advanced stage of maturity. We found a broad range of sophistication/complication in terms of the methods applied in assessing and mapping benthic habitats. The simplest index or metric involved some assessment of species richness, while the most complicated required utilizing multi-variate analysis. The simplest mapping attempts equated physical substrate with benthic habitat while the most sophisticated relied on extensive environmental preference and groundtruth data for species of concern. The leading edge of methods for benthic habitat mapping involves combining the advances in optical and acoustic methods that allow for routine classifying and mapping of the seafloor with biological and habitat data for species of concern. The objective of this melding of dispirit methods is to produce benthic habitat maps with broad system wide coverage and sound biological underpinning. It is clear that the disparity in information density between the physical and biological sides of the equation currently hinder applicability and acceptability of benthic habitat mapping efforts. In addition to the lack of basic information on the biological and environmental tolerances of targeted species, the proliferation of metrics for characterizing and assessing biological conditions further clouds the usefulness of any broad scale mapping attempt. The problem of data density mismatch between physical and biological methods will likely not be solved until acoustic methods can routinely resolve the elusive biological components that make a physical substrate a habitat.

  2. Habitat Suitability Index Models: Muskellunge

    USGS Publications Warehouse

    Cook, Mark F.; Solomon, R. Charles

    1987-01-01

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

  3. Habitat Suitability Index Models: Bobcat

    USGS Publications Warehouse

    Boyle, Katherine A.; Fendley, Timothy T.

    1987-01-01

    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.

  4. Meso-scale habitat simulation for the conservation of the endangered crayfish Austropotamobious pallipes complex in Italy

    NASA Astrophysics Data System (ADS)

    Vezza, Paolo; Ghia, Daniela; Fea, Gianluca; Spairani, Michele; Comoglio, Claudio; Di Francesco, Monica

    2014-05-01

    Crayfish are the largest mobile freshwater invertebrates, being often considered key species in the aquatic ecosystems of small streams and creeks in Italy. Specifically, Austropotamobius pallipes complex is currently classified as an endangered species, and Italian local populations significantly decreased over the last decades due to habitat modifications and introduction of alien species. Information on A. pallipes ecological requirements is then needed to quantify habitat loss, to simulate restoration scenarios and to implement effective conservation measures. In this work we analyze mesohabitat use of A. pallipes in reference streams and creeks located in the Italian pre-Alps (Lombardia region) and in the mountainous areas of the Gran Sasso e monti della Laga National Park (Abruzzo region). Data from seven morphologically different streams were used to calibrate and validate habitat models for the endangered crayfish A. pallipes complex. The Random Forests algorithm was used to identify the best and the most parsimonious habitat model, to define the lowest number of variables to be surveyed in future model applications. The obtained habitat models were then applied to each stream in order to classify each mesohabitat into suitability categories, and to develop habitat-flow rating curves. Finally, habitat time series analysis was used to define detailed schemes of flow management for individual water diversions in order to represent how physical habitat changes through time and to identify stress conditions for A. pallipes created by persistent limitation in habitat availability. Results indicated that fine substrate (as proportion of gravel and sand), shallow water depth and cover (as presence of boulders, woody debris and undercut banks) revealed to be significant variables for the occurrence of A. pallipes. Habitat models, performing well in both model calibration and validation phases (accuracy ranging from 71% to 87%), are regarded as valuable tools being

  5. Impacts of Discharge Reductions on Physical and Thermal Habitat Characteristics in a Desert Spring, Death Valley National Park, California, USA

    NASA Astrophysics Data System (ADS)

    Morrison, R. R.; Stone, M. C.; Sada, D. W.

    2013-12-01

    Desert springs are biodiversity hotspots that are sensitive to anthropogenic activities. Despite their importance, the effects of human disturbance on desert springs are not well known, and scarce information exists describing the biotic or environmental effects of incrementally increasing disturbance. The objective of this research was to quantify the influence of incremental reductions in discharge on the physical and thermal characteristics of a desert springbrook. This objective was accomplished through a combination of field experiments at Travertine Spring in Death Valley National Park, USA, and hydraulic/temperature modeling in order to: (1) quantify changes in physical characteristics of the springbrook channel and aquatic environment; (2) investigate the effects of reduced spring discharge on seasonal spatial temperature patterns; (3) delineate tipping points that exhibit a non-linear response to decreased flow. The study results supported our predictions that decreased discharge would modify physical habitat characteristics of the springbrook, reduce aquatic habitat volume, increase variability in water temperatures along the springbrook, and reduce springbrook suitability for invertebrates that require stable environments. Field observations revealed a significant relationship between water depth and flow velocity with reduced spring discharge. The rate of change of mean water depths, velocities, and habitat volumes were greatest with only a 10% reduction in spring flow. In addition, a non-linear temperature response to flow reductions was present under all modeled conditions. Generally, water temperature gradients increased as flows were decreased, and the sensitivity of reduced discharge increased with distance from the spring source. The degree of sensitivity was a function of season, which reflects the influence of ambient air temperature and wind in the cooling of the springbrook. These results suggest that habitat for species using stable thermal

  6. A geospatial modelling approach to predict seagrass habitat recovery under multiple stressor regimes

    EPA Science Inventory

    Restoration of estuarine seagrass habitats requires a clear understanding of the modes of action of multiple interacting stressors including nutrients, climate change, coastal land-use change, and habitat modification. We have developed and demonstrated a geospatial modeling a...

  7. EFFECT OF URBANIZATION ON FISH ASSEMBLAGES AND HABITAT QUALITY IN A PIEDMONT RIVER BASIN

    EPA Science Inventory

    We quantified the relationships among urbanization, fishes, and habitat quality to determine how assemblags respond to urbanization and if a habitat quality assessment reflects urban effects on stream ecosystems. We sampled 30 wadeable streams along an urban gradient in the Etow...

  8. Reconstructing fish movements between coastal wetland and nearshore habitats of the Great Lakes

    EPA Science Inventory

    The use of resources from multiple habitats has been shown to be important to the production of aquatic consumers. To quantify the support of Great Lakes coastal wetland (WL) and nearshore (NS) habitats to yellow perch, we used otolith microchemistry to trace movements between th...

  9. RELATIONSHIPS BETWEEN HABITAT QUALITY AND DENSITY OF JUVENILE WINTER FLOUNDER

    EPA Science Inventory

    We used a digital video camera mounted to a 1-m beam trawl together with an attached continuous recording YSI sonde and GPS unit to quantify juvenile winter flounder (Pseudopleuronectes americanus) densities and fish habitat. The YSI sonde measured temperature, salinity, dissolve...

  10. Habitat goes green

    SciTech Connect

    Kriescher, P.; Smith, M.

    1999-12-01

    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.

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

    PubMed Central

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

    2011-01-01

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

  12. Lunar microcosmos. [human factors of lunar habitat

    NASA Technical Reports Server (NTRS)

    Pirie, N.

    1974-01-01

    A human habitat on the lunar surface requires energy recycling metabolites based on the utilization of vegetative plants that are good photosynthesizers. Selection criteria involve reactions to fertilization by human excrements, suitability as food for man (with or without fractionation), physiological effects of prolonged ingestion of these plants, and technical methods for returning inedible portions back into the cycle.

  13. Scale considerations in monitoring greater sage-grouse ( Centrocercus urophasianus) vegetation structure and habitat suitability within nesting habitat in western Wyoming

    NASA Astrophysics Data System (ADS)

    Zabihi Afratakhti, Khodabakhsh

    Disturbance of nesting habitat associated with energy development has contributed to population declines of greater sage-grouse (Centrocercus urophasianus) in western Wyoming. Greater sage-grouse, rely on sagebrush ecosystems during all of their life stages. Specific criteria for suitable nesting habitat for the species includes both amount and distribution of sagebrush and herbaceous cover. Loss of suitable sagebrush habitat makes the identification of remaining suitable habitat critical for long-term management of the species. This research documents spatial patterns of vegetation structure within greater sage-grouse nesting habitat to compare shrub configuration (shrub patchiness) between nest and random non-nest locations at very fine scales. Additionally, we examine the applicability of gap intercept techniques to quantify shrub structural characteristics (shrub height and patchiness). Finally, the suitability of nesting habitats was mapped using biophysical features and anthropogenic disturbances at fine to broad scales. Spatial vegetation patterns vary with scale, and spatial homogeneity of sagebrush stands declines with increasing shrub height. Canopy gap intercept techniques reliably quantify composition, configuration, and height of shrub cover. The proportion of shrub cover and non-shrub gaps can be used as a compositional attribute that characterizes nesting habitat at the broad scale (across kilometers). In addition, variation in gap sizes within shrub cover, or shrub patchiness is a habitat characteristic that differentiates nesting and non-nest habitat at fine scales. Shrub cover-to-gap proportion, shrub spatial configuration, and mean shrub heights are important vegetative traits that characterize sage-grouse nesting habitat. At broad scales, habitat suitability for nesting is related to both anthropogenic disturbances and the suitability of biophysical features (e.g., slope, aspect, vegetation type and composition). Information about habitat

  14. Quantifying macromolecular conformational transition pathways

    NASA Astrophysics Data System (ADS)

    Seyler, Sean; Kumar, Avishek; Thorpe, Michael; Beckstein, Oliver

    2015-03-01

    Diverse classes of proteins function through large-scale conformational changes that are challenging for computer simulations. A range of fast path-sampling techniques have been used to generate transitions, but it has been difficult to compare paths from (and assess the relative strengths of) different methods. We introduce a comprehensive method (pathway similarity analysis, PSA) for quantitatively characterizing and comparing macromolecular pathways. The Hausdorff and Fréchet metrics (known from computational geometry) are used to quantify the degree of similarity between polygonal curves in configuration space. A strength of PSA is its use of the full information available from the 3 N-dimensional configuration space trajectory without requiring additional specific knowledge about the system. We compare a sample of eleven different methods for the closed-to-open transitions of the apo enzyme adenylate kinase (AdK) and also apply PSA to an ensemble of 400 AdK trajectories produced by dynamic importance sampling MD and the Geometrical Pathways algorithm. We discuss the method's potential to enhance our understanding of transition path sampling methods, validate them, and help guide future research toward deeper physical insights into conformational transitions.

  15. Mapping Habitats and Developing Baselines in Offshore Marine Reserves with Little Prior Knowledge: A Critical Evaluation of a New Approach.

    PubMed

    Lawrence, Emma; Hayes, Keith R; Lucieer, Vanessa L; Nichol, Scott L; Dambacher, Jeffrey M; Hill, Nicole A; Barrett, Neville; Kool, Johnathan; Siwabessy, Justy

    2015-01-01

    The recently declared Australian Commonwealth Marine Reserve (CMR) Network covers a total of 3.1 million km2 of continental shelf, slope, and abyssal habitat. Managing and conserving the biodiversity values within this network requires knowledge of the physical and biological assets that lie within its boundaries. Unfortunately very little is known about the habitats and biological assemblages of the continental shelf within the network, where diversity is richest and anthropogenic pressures are greatest. Effective management of the CMR estate into the future requires this knowledge gap to be filled efficiently and quantitatively. The challenge is particularly great for the shelf as multibeam echosounder (MBES) mapping, a key tool for identifying and quantifying habitat distribution, is time consuming in shallow depths, so full coverage mapping of the CMR shelf assets is unrealistic in the medium-term. Here we report on the results of a study undertaken in the Flinders Commonwealth Marine Reserve (southeast Australia) designed to test the benefits of two approaches to characterising shelf habitats: (i) MBES mapping of a continuous (~30 km2) area selected on the basis of its potential to include a range of seabed habitats that are potentially representative of the wider area, versus; (ii) a novel approach that uses targeted mapping of a greater number of smaller, but spatially balanced, locations using a Generalized Random Tessellation Stratified sample design. We present the first quantitative estimates of habitat type and sessile biological communities on the shelf of the Flinders reserve, the former based on three MBES analysis techniques. We contrast the quality of information that both survey approaches offer in combination with the three MBES analysis methods. The GRTS approach enables design based estimates of habitat types and sessile communities and also identifies potential biodiversity hotspots in the northwest corner of the reserve's IUCN zone IV, and in

  16. Mapping Habitats and Developing Baselines in Offshore Marine Reserves with Little Prior Knowledge: A Critical Evaluation of a New Approach

    PubMed Central

    Lawrence, Emma; Hayes, Keith R.; Lucieer, Vanessa L.; Nichol, Scott L.; Dambacher, Jeffrey M.; Hill, Nicole A.; Barrett, Neville; Kool, Johnathan; Siwabessy, Justy

    2015-01-01

    The recently declared Australian Commonwealth Marine Reserve (CMR) Network covers a total of 3.1 million km2 of continental shelf, slope, and abyssal habitat. Managing and conserving the biodiversity values within this network requires knowledge of the physical and biological assets that lie within its boundaries. Unfortunately very little is known about the habitats and biological assemblages of the continental shelf within the network, where diversity is richest and anthropogenic pressures are greatest. Effective management of the CMR estate into the future requires this knowledge gap to be filled efficiently and quantitatively. The challenge is particularly great for the shelf as multibeam echosounder (MBES) mapping, a key tool for identifying and quantifying habitat distribution, is time consuming in shallow depths, so full coverage mapping of the CMR shelf assets is unrealistic in the medium-term. Here we report on the results of a study undertaken in the Flinders Commonwealth Marine Reserve (southeast Australia) designed to test the benefits of two approaches to characterising shelf habitats: (i) MBES mapping of a continuous (~30 km2) area selected on the basis of its potential to include a range of seabed habitats that are potentially representative of the wider area, versus; (ii) a novel approach that uses targeted mapping of a greater number of smaller, but spatially balanced, locations using a Generalized Random Tessellation Stratified sample design. We present the first quantitative estimates of habitat type and sessile biological communities on the shelf of the Flinders reserve, the former based on three MBES analysis techniques. We contrast the quality of information that both survey approaches offer in combination with the three MBES analysis methods. The GRTS approach enables design based estimates of habitat types and sessile communities and also identifies potential biodiversity hotspots in the northwest corner of the reserve’s IUCN zone IV, and

  17. Mapping Habitats and Developing Baselines in Offshore Marine Reserves with Little Prior Knowledge: A Critical Evaluation of a New Approach.

    PubMed

    Lawrence, Emma; Hayes, Keith R; Lucieer, Vanessa L; Nichol, Scott L; Dambacher, Jeffrey M; Hill, Nicole A; Barrett, Neville; Kool, Johnathan; Siwabessy, Justy

    2015-01-01

    The recently declared Australian Commonwealth Marine Reserve (CMR) Network covers a total of 3.1 million km2 of continental shelf, slope, and abyssal habitat. Managing and conserving the biodiversity values within this network requires knowledge of the physical and biological assets that lie within its boundaries. Unfortunately very little is known about the habitats and biological assemblages of the continental shelf within the network, where diversity is richest and anthropogenic pressures are greatest. Effective management of the CMR estate into the future requires this knowledge gap to be filled efficiently and quantitatively. The challenge is particularly great for the shelf as multibeam echosounder (MBES) mapping, a key tool for identifying and quantifying habitat distribution, is time consuming in shallow depths, so full coverage mapping of the CMR shelf assets is unrealistic in the medium-term. Here we report on the results of a study undertaken in the Flinders Commonwealth Marine Reserve (southeast Australia) designed to test the benefits of two approaches to characterising shelf habitats: (i) MBES mapping of a continuous (~30 km2) area selected on the basis of its potential to include a range of seabed habitats that are potentially representative of the wider area, versus; (ii) a novel approach that uses targeted mapping of a greater number of smaller, but spatially balanced, locations using a Generalized Random Tessellation Stratified sample design. We present the first quantitative estimates of habitat type and sessile biological communities on the shelf of the Flinders reserve, the former based on three MBES analysis techniques. We contrast the quality of information that both survey approaches offer in combination with the three MBES analysis methods. The GRTS approach enables design based estimates of habitat types and sessile communities and also identifies potential biodiversity hotspots in the northwest corner of the reserve's IUCN zone IV, and in

  18. Semi-automted analysis of high-resolution aerial images to quantify docks in Upper Midwest glacial lakes

    USGS Publications Warehouse

    Beck, Marcus W.; Vondracek, Bruce C.; Hatch, Lorin K.; Vinje, Jason

    2013-01-01

    Lake resources can be negatively affected by environmental stressors originating from multiple sources and different spatial scales. Shoreline development, in particular, can negatively affect lake resources through decline in habitat quality, physical disturbance, and impacts on fisheries. The development of remote sensing techniques that efficiently characterize shoreline development in a regional context could greatly improve management approaches for protecting and restoring lake resources. The goal of this study was to develop an approach using high-resolution aerial photographs to quantify and assess docks as indicators of shoreline development. First, we describe a dock analysis workflow that can be used to quantify the spatial extent of docks using aerial images. Our approach incorporates pixel-based classifiers with object-based techniques to effectively analyze high-resolution digital imagery. Second, we apply the analysis workflow to quantify docks for 4261 lakes managed by the Minnesota Department of Natural Resources. Overall accuracy of the analysis results was 98.4% (87.7% based on ) after manual post-processing. The analysis workflow was also 74% more efficient than the time required for manual digitization of docks. These analyses have immediate relevance for resource planning in Minnesota, whereas the dock analysis workflow could be used to quantify shoreline development in other regions with comparable imagery. These data can also be used to better understand the effects of shoreline development on aquatic resources and to evaluate the effects of shoreline development relative to other stressors.

  19. The interaction of intraspecific competition and habitat on individual diet specialization: a near range-wide examination of sea otters.

    PubMed

    Newsome, Seth D; Tinker, M Tim; Gill, Verena A; Hoyt, Zachary N; Doroff, Angela; Nichol, Linda; Bodkin, James L

    2015-05-01

    The quantification of individuality is a common research theme in the fields of population, community, and evolutionary ecology. The potential for individuality to arise is likely context-dependent, and the influence of habitat characteristics on its prevalence has received less attention than intraspecific competition. We examined individual diet specialization in 16 sea otter (Enhydra lutris) populations from southern California to the Aleutian Islands in Alaska. Because population histories, relative densities, and habitat characteristics vary widely among sites, we could examine the effects of intraspecific competition and habitat on the prevalence of individual diet specialization. Using observed diet data, we classified half of our sites as rocky substrate habitats and the other half containing a mixture of rocky and unconsolidated (soft) sediment substrates. We used stable isotope data to quantify population- and individual-level diet variation. Among rocky substrate sites, the slope [±standard error (SE)] of the positive significant relationship between the within-individual component (WIC) and total isotopic niche width (TINW) was shallow (0.23 ± 0.07) and negatively correlated with sea otter density. In contrast, the slope of the positive WIC/TINW relationship for populations inhabiting mixed substrate habitats was much higher (0.53 ± 0.14), suggesting a low degree of individuality, irrespective of intraspecific competition. Our results show that the potential for individuality to occur as a result of increasing intraspecific competition is context-dependent and that habitat characteristics, which ultimately influence prey diversity, relative abundance, and the range of skillsets required for efficient prey procurement, are important in determining when and where individual diet specialization occurs in nature.

  20. The interaction of intraspecific competition and habitat on individual diet specialization: a near range-wide examination of sea otters

    USGS Publications Warehouse

    Newsome, Seth D.; Tinker, M. Tim; Gill, Verena A.; Hoyt, Zachary N.; Doroff, Angela; Nichol, Linda; Bodkin, James L.

    2015-01-01

    The quantification of individuality is a common research theme in the fields of population, community, and evolutionary ecology. The potential for individuality to arise is likely context-dependent, and the influence of habitat characteristics on its prevalence has received less attention than intraspecific competition. We examined individual diet specialization in 16 sea otter (Enhydra lutris) populations from southern California to the Aleutian Islands in Alaska. Because population histories, relative densities, and habitat characteristics vary widely among sites, we could examine the effects of intraspecific competition and habitat on the prevalence of individual diet specialization. Using observed diet data, we classified half of our sites as rocky substrate habitats and the other half containing a mixture of rocky and unconsolidated (soft) sediment substrates. We used stable isotope data to quantify population- and individual-level diet variation. Among rocky substrate sites, the slope [±standard error (SE)] of the positive significant relationship between the within-individual component (WIC) and total isotopic niche width (TINW) was shallow (0.23 ± 0.07) and negatively correlated with sea otter density. In contrast, the slope of the positive WIC/TINW relationship for populations inhabiting mixed substrate habitats was much higher (0.53 ± 0.14), suggesting a low degree of individuality, irrespective of intraspecific competition. Our results show that the potential for individuality to occur as a result of increasing intraspecific competition is context-dependent and that habitat characteristics, which ultimately influence prey diversity, relative abundance, and the range of skillsets required for efficient prey procurement, are important in determining when and where individual diet specialization occurs in nature.

  1. The interaction of intraspecific competition and habitat on individual diet specialization: a near range-wide examination of sea otters.

    PubMed

    Newsome, Seth D; Tinker, M Tim; Gill, Verena A; Hoyt, Zachary N; Doroff, Angela; Nichol, Linda; Bodkin, James L

    2015-05-01

    The quantification of individuality is a common research theme in the fields of population, community, and evolutionary ecology. The potential for individuality to arise is likely context-dependent, and the influence of habitat characteristics on its prevalence has received less attention than intraspecific competition. We examined individual diet specialization in 16 sea otter (Enhydra lutris) populations from southern California to the Aleutian Islands in Alaska. Because population histories, relative densities, and habitat characteristics vary widely among sites, we could examine the effects of intraspecific competition and habitat on the prevalence of individual diet specialization. Using observed diet data, we classified half of our sites as rocky substrate habitats and the other half containing a mixture of rocky and unconsolidated (soft) sediment substrates. We used stable isotope data to quantify population- and individual-level diet variation. Among rocky substrate sites, the slope [±standard error (SE)] of the positive significant relationship between the within-individual component (WIC) and total isotopic niche width (TINW) was shallow (0.23 ± 0.07) and negatively correlated with sea otter density. In contrast, the slope of the positive WIC/TINW relationship for populations inhabiting mixed substrate habitats was much higher (0.53 ± 0.14), suggesting a low degree of individuality, irrespective of intraspecific competition. Our results show that the potential for individuality to occur as a result of increasing intraspecific competition is context-dependent and that habitat characteristics, which ultimately influence prey diversity, relative abundance, and the range of skillsets required for efficient prey procurement, are important in determining when and where individual diet specialization occurs in nature. PMID:25645269

  2. Thermoregulatory strategies in an aquatic ectotherm from thermally-constrained habitats: An evaluation of current approaches.

    PubMed

    Piasečná, Karin; Pončová, Alena; Tejedo, Miguel; Gvoždík, Lumír

    2015-08-01

    Many ectotherms employ diverse behavioral adjustments to effectively buffer the spatio-temporal variation in environmental temperatures, whereas others remain passive to thermal heterogeneity. Thermoregulatory studies are frequently performed on species living in thermally benign habitats, which complicate understanding of the thermoregulation-thermoconformity continuum. The need for new empirical data from ectotherms exposed to thermally challenging conditions requires the evaluation of available methods for quantifying thermoregulatory strategies. We evaluated the applicability of various thermoregulatory indices using fire salamander larvae, Salamandra salamandra, in two aquatic habitats, a forest pool and well, as examples of disparate thermally-constrained environments. Water temperatures in the well were lower and less variable than in the pool. Thermal conditions prevented larvae from reaching their preferred body temperature range in both water bodies. In contrast to their thermoregulatory abilities examined in a laboratory thermal gradient, field body temperatures only matched the mean and range of operative temperatures, showing thermal passivity of larvae in both habitats. Despite apparent thermoconformity, thermoregulatory indices indicated various strategies from active thermoregulation, to thermoconformity, and even thermal evasion, which revealed their limited applicability under thermally-constrained conditions. Salamander larvae abandoned behavioral thermoregulation despite varying opportunities to increase their body temperature above average water temperatures. Thermoconformity represents a favored strategy in these ectotherms living in more thermally-constrained environments than those examined in previous thermoregulatory studies. To understand thermal ecology and its impact on population dynamics, the quantification of thermoregulatory strategies of ectotherms in thermally-constrained habitats requires the careful choice of an appropriate

  3. Thermoregulatory strategies in an aquatic ectotherm from thermally-constrained habitats: An evaluation of current approaches.

    PubMed

    Piasečná, Karin; Pončová, Alena; Tejedo, Miguel; Gvoždík, Lumír

    2015-08-01

    Many ectotherms employ diverse behavioral adjustments to effectively buffer the spatio-temporal variation in environmental temperatures, whereas others remain passive to thermal heterogeneity. Thermoregulatory studies are frequently performed on species living in thermally benign habitats, which complicate understanding of the thermoregulation-thermoconformity continuum. The need for new empirical data from ectotherms exposed to thermally challenging conditions requires the evaluation of available methods for quantifying thermoregulatory strategies. We evaluated the applicability of various thermoregulatory indices using fire salamander larvae, Salamandra salamandra, in two aquatic habitats, a forest pool and well, as examples of disparate thermally-constrained environments. Water temperatures in the well were lower and less variable than in the pool. Thermal conditions prevented larvae from reaching their preferred body temperature range in both water bodies. In contrast to their thermoregulatory abilities examined in a laboratory thermal gradient, field body temperatures only matched the mean and range of operative temperatures, showing thermal passivity of larvae in both habitats. Despite apparent thermoconformity, thermoregulatory indices indicated various strategies from active thermoregulation, to thermoconformity, and even thermal evasion, which revealed their limited applicability under thermally-constrained conditions. Salamander larvae abandoned behavioral thermoregulation despite varying opportunities to increase their body temperature above average water temperatures. Thermoconformity represents a favored strategy in these ectotherms living in more thermally-constrained environments than those examined in previous thermoregulatory studies. To understand thermal ecology and its impact on population dynamics, the quantification of thermoregulatory strategies of ectotherms in thermally-constrained habitats requires the careful choice of an appropriate

  4. Structural Health System for Crew Habitats

    NASA Technical Reports Server (NTRS)

    Brandon, Erik

    2005-01-01

    This viewgraph presentation reviews the history of JPL, and its affilation with CalTech and NASA. It continues by examining some of the sensors, and systems to ensure structural health that JPL has developed. It also reviews some of the habitat designs that are being developed for the lunar base. With these crew habitats, there is a requirement to have embedded systems health monitoring, to alert the crew in time about adverse structural conditions. The use of sensing technologies and smart materials are being developed to assure mechanical flexibility, minimumally invasive, autonomous, and enhanced reliability.

  5. Habitat Evaluation Procedures (HEP) Report; Carey Creek, Technical Report 2005.

    SciTech Connect

    Entz, Ray

    2005-05-01

    In August 2002, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the Carey Creek property, an acquisition completed by the Kalispel Tribe of Indians in December 2001. Evaluation species and appropriate models include bald eagle, black-capped chickadee, Canada goose, mallard, yellow warbler, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The Carey Creek Project provides a total of 172.95 Habitat Units (HUs) for the species evaluated. Conifer forest habitat provides 4.91 HUs for bald eagle, black-capped chickadee, and white-tailed deer. Forested wetlands provide 52.68 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. Scrub-shrub wetlands provide 2.82 HUs for mallard, yellow warbler and white-tailed deer. Wet meadow and grassland meadow provide 98.13 HUs for mallard and Canada goose. Emergent wetlands provide 11.53 HUs for mallard, muskrat, and Canada goose. Open water provides 2.88 HUs for Canada goose, mallard, and muskrat. The objective of using HEP at the Carey Creek Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  6. Spring foraging distribution and habitat selection by Double-crested Cormorants on the Penobscot River, Maine USA

    USGS Publications Warehouse

    Blackwell, B.F.; Krohn, W.B.

    1997-01-01

    Restoration of the Atlantic salmon (Salmo salar) to New England rivers requires, in part, an understanding of the use of habitat and prey by potential and known predators. We examined variation in habitat use by Double-crested Cormorants (Phalacrocorax auritius), from April through June 1992-94 on ca. 288 km of the 2 primary tributaries and the mainstem of the Penobscot River, Maine. Our objectives were to quantify temporal and spatial variation in habitat use and test for selection of spring foraging habitats by cormorants. Cormorants forage during daylight hours only. To determine the distribution of foraging birds we conducted aerial surveys at intervals of 105 km north of the mouth of the mainstem. However, from late April through early June of all years, birds selected (P < 0.05) 4 of the 5 mainstem dams and the estuarine portion of the river. Cormorant use of dams remained at or above expected levels until the second week of June in all years. We suggest that cormorant selection for foraging areas adjacent to dams reflected a higher availability of prey, possibly due to delay and injury of migrating Atlantic salmon smolts. Cormorant selection of the estuarine portion of the Penobscot River was likely a response to a seasonally increasing availability and abundance of estuarine and marine prey, in addition to resident freshwater species and migrating smolts.

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

    ERIC Educational Resources Information Center

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

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

  8. Predictive Modeling of Spinner Dolphin (Stenella longirostris) Resting Habitat in the Main Hawaiian Islands

    PubMed Central

    Thorne, Lesley H.; Johnston, David W.; Urban, Dean L.; Tyne, Julian; Bejder, Lars; Baird, Robin W.; Yin, Suzanne; Rickards, Susan H.; Deakos, Mark H.; Mobley, Joseph R.; Pack, Adam A.; Chapla Hill, Marie

    2012-01-01

    Predictive habitat models can provide critical information that is necessary in many conservation applications. Using Maximum Entropy modeling, we characterized habitat relationships and generated spatial predictions of spinner dolphin (Stenella longirostris) resting habitat in the main Hawaiian Islands. Spinner dolphins in Hawai'i exhibit predictable daily movements, using inshore bays as resting habitat during daylight hours and foraging in offshore waters at night. There are growing concerns regarding the effects of human activities on spinner dolphins resting in coastal areas. However, the environmental factors that define suitable resting habitat remain unclear and must be assessed and quantified in order to properly address interactions between humans and spinner dolphins. We used a series of dolphin sightings from recent surveys in the main Hawaiian Islands and a suite of environmental variables hypothesized as being important to resting habitat to model spinner dolphin resting habitat. The model performed well in predicting resting habitat and indicated that proximity to deep water foraging areas, depth, the proportion of bays with shallow depths, and rugosity were important predictors of spinner dolphin habitat. Predicted locations of suitable spinner dolphin resting habitat provided in this study indicate areas where future survey efforts should be focused and highlight potential areas of conflict with human activities. This study provides an example of a presence-only habitat model used to inform the management of a species for which patterns of habitat availability are poorly understood. PMID:22937022

  9. The decline of the European eel Anguilla anguilla: quantifying and managing escapement to support conservation.

    PubMed

    Bilotta, G S; Sibley, P; Hateley, J; Don, A

    2011-01-01

    A method was developed to quantify the number and biomass of European eels Anguilla anguilla escaping to the ocean for breeding. The non-intrusive method, involving a fixed-position, high-frequency multi-beam sonar, permitted constant surveillance of A. anguilla movements throughout their 5 month escapement season (July to December). During this period, >1000 individuals were monitored escaping to the Atlantic Ocean from their freshwater habitat in the River Huntspill study site (Somerset, U.K.). The total length of each fish was measured using the sonar software. These measurements were then converted to an estimate of mass using a length:mass regression relationship derived from historical fyke-net data from this site, comprising c. 500 A. anguilla length:mass measurements collected over a 10 year period. The net biomass of escapement from the study site was equivalent to c. 6 kg ha⁻¹ year⁻¹, lower than the present European target which would require at least 7 kg ha⁻¹ year⁻¹ from this habitat. These findings demonstrate the capabilities of this monitoring technique and its usefulness both as a tool to assess the compliance with conservation targets and as a tool to evaluate the success of conservation measures for elusive aquatic species such as A. anguilla.

  10. Children's interpretations of general quantifiers, specific quantifiers, and generics

    PubMed Central

    Gelman, Susan A.; Leslie, Sarah-Jane; Was, Alexandra M.; Koch, Christina M.

    2014-01-01

    Recently, several scholars have hypothesized that generics are a default mode of generalization, and thus that young children may at first treat quantifiers as if they were generic in meaning. To address this issue, the present experiment provides the first in-depth, controlled examination of the interpretation of generics compared to both general quantifiers ("all Xs", "some Xs") and specific quantifiers ("all of these Xs", "some of these Xs"). We provided children (3 and 5 years) and adults with explicit frequency information regarding properties of novel categories, to chart when "some", "all", and generics are deemed appropriate. The data reveal three main findings. First, even 3-year-olds distinguish generics from quantifiers. Second, when children make errors, they tend to be in the direction of treating quantifiers like generics. Third, children were more accurate when interpreting specific versus general quantifiers. We interpret these data as providing evidence for the position that generics are a default mode of generalization, especially when reasoning about kinds. PMID:25893205

  11. The Nutritional Geometry of Resource Scarcity: Effects of Lean Seasons and Habitat Disturbance on Nutrient Intakes and Balancing in Wild Sifakas.

    PubMed

    Irwin, Mitchell T; Raharison, Jean-Luc; Raubenheimer, David R; Chapman, Colin A; Rothman, Jessica M

    2015-01-01

    Animals experience spatial and temporal variation in food and nutrient supply, which may cause deviations from optimal nutrient intakes in both absolute amounts (meeting nutrient requirements) and proportions (nutrient balancing). Recent research has used the geometric framework for nutrition to obtain an improved understanding of how animals respond to these nutritional constraints, among them free-ranging primates including spider monkeys and gorillas. We used this framework to examine macronutrient intakes and nutrient balancing in sifakas (Propithecus diadema) at Tsinjoarivo, Madagascar, in order to quantify how these vary across seasons and across habitats with varying degrees of anthropogenic disturbance. Groups in intact habitat experience lean season decreases in frugivory, amounts of food ingested, and nutrient intakes, yet preserve remarkably constant proportions of dietary macronutrients, with the proportional contribution of protein to the diet being highly consistent. Sifakas in disturbed habitat resemble intact forest groups in the relative contribution of dietary macronutrients, but experience less seasonality: all groups' diets converge in the lean season, but disturbed forest groups largely fail to experience abundant season improvements in food intake or nutritional outcomes. These results suggest that: (1) lemurs experience seasonality by maintaining nutrient balance at the expense of calories ingested, which contrasts with earlier studies of spider monkeys and gorillas, (2) abundant season foods should be the target of habitat management, even though mortality might be concentrated in the lean season, and (3) primates' within-group competitive landscapes, which contribute to variation in social organization, may vary in complex ways across habitats and seasons.

  12. The Nutritional Geometry of Resource Scarcity: Effects of Lean Seasons and Habitat Disturbance on Nutrient Intakes and Balancing in Wild Sifakas

    PubMed Central

    Irwin, Mitchell T.; Raharison, Jean-Luc; Raubenheimer, David R.; Chapman, Colin A.; Rothman, Jessica M.

    2015-01-01

    Animals experience spatial and temporal variation in food and nutrient supply, which may cause deviations from optimal nutrient intakes in both absolute amounts (meeting nutrient requirements) and proportions (nutrient balancing). Recent research has used the geometric framework for nutrition to obtain an improved understanding of how animals respond to these nutritional constraints, among them free-ranging primates including spider monkeys and gorillas. We used this framework to examine macronutrient intakes and nutrient balancing in sifakas (Propithecus diadema) at Tsinjoarivo, Madagascar, in order to quantify how these vary across seasons and across habitats with varying degrees of anthropogenic disturbance. Groups in intact habitat experience lean season decreases in frugivory, amounts of food ingested, and nutrient intakes, yet preserve remarkably constant proportions of dietary macronutrients, with the proportional contribution of protein to the diet being highly consistent. Sifakas in disturbed habitat resemble intact forest groups in the relative contribution of dietary macronutrients, but experience less seasonality: all groups’ diets converge in the lean season, but disturbed forest groups largely fail to experience abundant season improvements in food intake or nutritional outcomes. These results suggest that: (1) lemurs experience seasonality by maintaining nutrient balance at the expense of calories ingested, which contrasts with earlier studies of spider monkeys and gorillas, (2) abundant season foods should be the target of habitat management, even though mortality might be concentrated in the lean season, and (3) primates’ within-group competitive landscapes, which contribute to variation in social organization, may vary in complex ways across habitats and seasons. PMID:26061401

  13. The Nutritional Geometry of Resource Scarcity: Effects of Lean Seasons and Habitat Disturbance on Nutrient Intakes and Balancing in Wild Sifakas.

    PubMed

    Irwin, Mitchell T; Raharison, Jean-Luc; Raubenheimer, David R; Chapman, Colin A; Rothman, Jessica M

    2015-01-01

    Animals experience spatial and temporal variation in food and nutrient supply, which may cause deviations from optimal nutrient intakes in both absolute amounts (meeting nutrient requirements) and proportions (nutrient balancing). Recent research has used the geometric framework for nutrition to obtain an improved understanding of how animals respond to these nutritional constraints, among them free-ranging primates including spider monkeys and gorillas. We used this framework to examine macronutrient intakes and nutrient balancing in sifakas (Propithecus diadema) at Tsinjoarivo, Madagascar, in order to quantify how these vary across seasons and across habitats with varying degrees of anthropogenic disturbance. Groups in intact habitat experience lean season decreases in frugivory, amounts of food ingested, and nutrient intakes, yet preserve remarkably constant proportions of dietary macronutrients, with the proportional contribution of protein to the diet being highly consistent. Sifakas in disturbed habitat resemble intact forest groups in the relative contribution of dietary macronutrients, but experience less seasonality: all groups' diets converge in the lean season, but disturbed forest groups largely fail to experience abundant season improvements in food intake or nutritional outcomes. These results suggest that: (1) lemurs experience seasonality by maintaining nutrient balance at the expense of calories ingested, which contrasts with earlier studies of spider monkeys and gorillas, (2) abundant season foods should be the target of habitat management, even though mortality might be concentrated in the lean season, and (3) primates' within-group competitive landscapes, which contribute to variation in social organization, may vary in complex ways across habitats and seasons. PMID:26061401

  14. The Habitat Demonstration Unit Project

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

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

    PubMed

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

    2008-12-01

    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

  16. GIS habitat analysis for lesser prairie-chickens in southeastern New Mexico

    PubMed Central

    Johnson, Kristine; Neville, Teri B; Neville, Paul

    2006-01-01

    Background We conducted Geographic Information System (GIS) habitat analyses for lesser prairie-chicken (LPCH, Tympanuchus pallidicinctus) conservation planning. The 876,799 ha study area included most of the occupied habitat for the LPCH in New Mexico. The objectives were to identify and quantify: 1. suitable LPCH habitat in New Mexico, 2. conversion of native habitats, 3. potential for habitat restoration, and 4. unsuitable habitat available for oil and gas activities. Results We found 16% of suitable habitat (6% of the study area) distributed in 13 patches of at least 3,200 ha and 11% of suitable habitat (4% of the study area) distributed in four patches over 7,238 ha. The area converted from native vegetation types comprised 17% of the study area. Ninety-five percent of agricultural conversion occurred on private lands in the northeastern corner of the study area. Most known herbicide-related conversions (82%) occurred in rangelands in the western part of the study area, on lands managed primarily by the US Bureau of Land Management (BLM). We identified 88,190 ha (10% of the study area) of habitats with reasonable restoration potential. Sixty-two percent of the primary population area (PPA) contained occupied, suitable, or potentially suitable habitat, leaving 38% that could be considered for oil and gas development. Conclusion Although suitable LPCH habitat appears at first glance to be abundant in southeastern New Mexico, only a fraction of apparently suitable vegetation types constitute quality habitat. However, we identified habitat patches that could be restored through mesquite control or shin-oak reintroduction. The analysis also identified areas of unsuitable habitat with low restoration potential that could be targeted for oil and gas exploration, in lieu of occupied, high-quality habitats. Used in combination with GIS analysis and current LPCH population data, the habitat map represents a powerful conservation and management tool. PMID:17144922

  17. Dynamic habitat selection by two wading bird species with divergent foraging strategies in a seasonally fluctuating wetland

    USGS Publications Warehouse

    Beerens, J.M.; Gawlik, D.E.; Herring, G.; Cook, Mark I.

    2011-01-01

    Seasonal and annual variation in food availability during the breeding season plays an influential role in the population dynamics of many avian species. In highly dynamic ecosystems like wetlands, finding and exploiting food resources requires a flexible behavioral response that may produce different population trends that vary with a species' foraging strategy. We quantified dynamic foraging-habitat selection by breeding and radiotagged White Ibises (Eudocimus albus) and Great Egrets (Ardea alba) in the Florida Everglades, where fluctuation in food resources is pronounced because of seasonal drying and flooding. The White Ibis is a tactile "searcher" species in population decline that specializes on highly concentrated prey, whereas the Great Egret, in a growing population, is a visual "exploiter" species that requires lower prey concentrations. In a year with high food availability, resource-selection functions for both species included variables that changed over multiannual time scales and were associated with increased prey production. In a year with low food availability, resource-selection functions included short-term variables that concentrated prey (e.g., water recession rates and reversals in drying pattern), which suggests an adaptive response to poor foraging conditions. In both years, the White Ibis was more restricted in its use of habitats than the Great Egret. Real-time species-habitat suitability models were developed to monitor and assess the daily availability and quality of spatially explicit habitat resources for both species. The models, evaluated through hindcasting using independent observations, demonstrated that habitat use of the more specialized White Ibis was more accurately predicted than that of the more generalist Great Egret. ?? The American Ornithologists' Union, 2011.

  18. Spatiotemporal variation in range-wide Golden-cheeked Warbler habitat

    USGS Publications Warehouse

    Duarte, Adam; Jensen, Jennifer; Hatfield, Jeffrey S.; Weckerly, Floyd

    2013-01-01

    Habitat availability ultimately limits the distribution and abundance of wildlife species. Consequently, it is paramount to identify where wildlife habitat is and understand how it changes over time in order to implement large scale wildlife conservation plans. Yet, no work has quantified the degree of change in range-wide breeding habitat for the golden-cheeked warbler (Setophaga chrysoparia), despite the species being listed as endangered by the U.S. federal government. Thus, using available geographic information system (GIS) data and Landsat satellite imagery we quantified range-wide warbler breeding habitat change from 1999-2001 to 2010-2011. We detected a 29% reduction in total warbler breeding habitat and found that warbler breeding habitat was removed and became more fragmented at uneven rates across the warbler’s breeding range during this time period. This information will assist researchers and managers in prioritizing breeding habitat conservation efforts for the species and provide a foundation for more realistic carrying capacity scenarios when modeling golden-cheeked warbler populations over time. Additionally, this study highlights the need for future work centered on quantifying golden-cheeked warbler movement rates and distances in order to assess the degree of connectivity between increasingly fragmented habitat patches.

  19. Habitat and Recreational Fishing Opportunity in Tampa Bay: Linking Ecological and Ecosystem Services to Human Beneficiaries

    EPA Science Inventory

    Estimating value of estuarine habitat to human beneficiaries requires that we understand how habitat alteration impacts function through both production and delivery of ecosystem goods and services (EGS). Here we expand on the habitat valuation technique of Bell (1997) with an es...

  20. Measuring acoustic habitats

    PubMed Central

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-01-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies. PMID:25954500

  1. An Initial Mars Habitat (IMH)

    NASA Technical Reports Server (NTRS)

    Gutierrez, D. J.

    1993-01-01

    As long duration, manned missions to Mars are studied for feasibility, the requirements to maintain a crew for two years in hostile environments while allowing productive and necessary work to occur, quickly becomes a driving force. Based on a mission scenario developed in the Explorations Program Office at the Johnson Space, the Initial Mars Habitat (IMH) explores one solution to providing a six person crew with the necessary hardware, logistics and environment to support a 500 day Martian surface stay. Many key issues drove the development of this initial concept; crew safety, logistics resupply, crew productivity and several critical mission element assumptions such as the limitations of a surface lander. Consideration of expansion beyond the first mission to an enhanced capability base was also integrated into the development of the IMH.

  2. Assessing functional equivalency of nekton habitat in enhanced habitats: Comparison of terraced and unterraced marsh ponds

    USGS Publications Warehouse

    La Peyre, M.K.; Gossman, B.; Nyman, J.A.

    2007-01-01

    be significantly lower in terraced versus unterraced ponds (p < 0.05). To properly assess the ecological equivalency of restored or rehabilitated sites for nekton requires that we move beyond measures of nekton density, biomass, and diversity and incorporate measures of functional equivalency, including habitat measures. ?? 2007 Estuarine Research Federation.

  3. Habitat Evaluation Procedures (HEP) Report : West Beaver Lake, 2004-2005 Technical Report.

    SciTech Connect

    Entz, Ray

    2005-02-01

    On September 7, 2004, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the West Beaver Lake property, an acquisition completed by the Kalispel Tribe of Indians in September 2004. Evaluation species and appropriate models include bald eagle, black-capped chickadee, mallard, muskrat, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The West Beaver Lake Project provides a total of 103.08 Habitat Units (HUs) for the species evaluated. Emergent wetland habitat provides 7.17 HUs for mallard and muskrat. Conifer forest habitat provides 95.91 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. The objective of using HEP at the West Beaver Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  4. Habitat selection and abundance of young-of-year smallmouth bass in north temperate lakes

    USGS Publications Warehouse

    Brown, Peter James; Bozek, Michael A.

    2010-01-01

    Habitat use during early life history plays an important role in the ecology of smallmouth bass Micropterus dolomieu in north temperate lakes. The highest levels of mortality occur during the first year of life, and the habitat selected probably affects mortality. We used resource selection functions and abundance data from two northern Wisconsin lakes to determine the habitats that influence the survival of smallmouth bass. Coarse substrates were consistently important to both nesting locations and young-of-year smallmouth bass. Young smallmouth bass used woody structure after swimming from their nests but disassociated themselves from habitats with more complex woody structure by August. Nonwoody cobble areas offer protection for young-of-year smallmouth bass without attracting predators, as woody habitats do. The decline in the abundance of young-of-year smallmouth bass was best fit to an exponential decay function in woody habitats, but in rock habitats it was linear. Habitat selection by young-of-year smallmouth bass shifts over time, and the shift is linked to predation risk: woody habitats initially offer them an advantage with respect to spawning but eventually provide their predators greater opportunities for ambush. This shift underscores the importance of having a diversity of littoral habitats. This study provides the first quantifiable analyses describing the habitat features selected by young-of-year smallmouth bass and links these descriptions to population dynamics.

  5. Resource Pulses in Desert River Habitats: Productivity-Biodiversity Hotspots, or Mirages?

    PubMed Central

    Free, Carissa L.; Baxter, Greg S.; Dickman, Christopher R.; Leung, Luke K. P.

    2013-01-01

    Resource pulses in the world's hot deserts are driven largely by rainfall and are highly variable in both time and space. However, run-on areas and drainage lines in arid regions receive more water more often than adjacent habitats, and frequently sustain relatively high levels of primary productivity. These landscape features therefore may support higher biotic diversity than other habitats, and potentially act as refuges for desert vertebrates and other biota during droughts. We used the ephemeral Field River in the Simpson Desert, central Australia, as a case study to quantify how resources and habitat characteristics vary spatially and temporally along the riparian corridor. Levels of moisture and nutrients were greater in the clay-dominated soils of the riverine corridor than in the surrounding sand dunes, as were cover values of trees, annual grasses, other annual plants and litter; these resources and habitat features were also greater near the main catchment area than in the distal reaches where the river channel runs out into extensive dune fields. These observations confirm that the riverine corridor is more productive than the surrounding desert, and support the idea that it may act as a refuge or as a channel for the ingress of peri-desert species. However, the work also demonstrates that species diversity of invertebrates and plants is not higher within the river corridor; rather, it is driven by rainfall and the accompanying increase in annual plants following a rain event. Further research is required to identify the biota that depend upon these resource pulses. PMID:24124446

  6. Habitat planning, maintenance and management working group

    SciTech Connect

    1997-03-01

    The Gulf of Mexico (GOM), called {open_quotes}America`s Sea,{close_quotes} is actually a small ocean basin covering over 1.5 million square kilometers. Because of the multiple uses, diversity, and size of the Gulf`s resources, management is shared by a number of governmental agencies including the Minerals Management Service, the Gulf of Mexico Fishery Management Council, the Gulf States Marine Fisheries Commission, National Marine Fisheries Service, the US Coast Guard, the US Army Corps of Engineers, and the five Gulf states fisheries agencies. All of these entities share a common goal of achieving optimum sustainable yield to maximize geological, biological, social, and economic benefits from these resources. These entities also share a common theme that the successful management of the northern GOM requires maintenance and enhancement of both the quantity and quality of habitats. A closer look at the GOM shows the sediment to be clearly dominated by vast sand and mud plains. These soft bottom habitats are preferred by many groundfish and shrimp species and, thus, have given rise to large commercial fisheries on these stocks. Hard bottom and reef habitats, on the other hand, are limited to approximately 1.6% of the total area of the Gulf, so that, while there are high demands by commercial and recreational fishermen for reef associated species, the availability of habitat for these stocks is limited. The thousands of oil and gas structures placed in the Gulf have added significant amounts of new hard substrate. The rigs-to-reefs concept was a common sense idea with support from environmental user groups and the petroleum industry for preserving a limited but valuable habitat type. As long as maximizing long-term benefits from the Gulf s resources for the greatest number of users remains the goal, then programs such as Rigs-to-Reefs will remain an important tool for fisheries and habitat managers in the Gulf.

  7. Quantifying errors without random sampling

    PubMed Central

    Phillips, Carl V; LaPole, Luwanna M

    2003-01-01

    Background All quantifications of mortality, morbidity, and other health measures involve numerous sources of error. The routine quantification of random sampling error makes it easy to forget that other sources of error can and should be quantified. When a quantification does not involve sampling, error is almost never quantified and results are often reported in ways that dramatically overstate their precision. Discussion We argue that the precision implicit in typical reporting is problematic and sketch methods for quantifying the various sources of error, building up from simple examples that can be solved analytically to more complex cases. There are straightforward ways to partially quantify the uncertainty surrounding a parameter that is not characterized by random sampling, such as limiting reported significant figures. We present simple methods for doing such quantifications, and for incorporating them into calculations. More complicated methods become necessary when multiple sources of uncertainty must be combined. We demonstrate that Monte Carlo simulation, using available software, can estimate the uncertainty resulting from complicated calculations with many sources of uncertainty. We apply the method to the current estimate of the annual incidence of foodborne illness in the United States. Summary Quantifying uncertainty from systematic errors is practical. Reporting this uncertainty would more honestly represent study results, help show the probability that estimated values fall within some critical range, and facilitate better targeting of further research. PMID:12892568

  8. Abyssal recipes revisited: A new physically-based approach to quantify the vertical diapycnal diffusion profile required to balance water masses formation by surface heat and freshwater fluxes with error bars.

    NASA Astrophysics Data System (ADS)

    Hochet, Antoine; Tailleux, Rémi; Kuhlbrodt, Till; Ferreira, David; Gregory, Jonathan

    2016-04-01

    We revisit the calculation of the diapycnal mixing required to equilibrate the formation of deep water made by Munk and Wunsch 1998 (MW). Our calculation is made possible by a new physically-based density variable, called thermodynamic neutral density, recently introduced by Tailleux 2016, which accurately approximates Jackett and McDougall 1997 empirical neutral density. Unlike neutral density, however, thermodynamic neutral density is a materially conserved variable. As a result, it can only change as the result of diabatic molecular diffusive effects by heat and salt, and is therefore more suitable for studying ocean mixing than neutral density, since the latter can also change as the result of non-material effects unrelated to mixing processes. Climatological temperature and salinity data are used along with heat and freshwater surface fluxes to estimate the dianeutral mean fluxes using a framework stemming from Walin 1982 ideas. The mean fluxes values are estimated to range between 0.2e-4 m^2/s and 5e-4 m^2/s for the densest waters and between 0.025e-4 m^2/s and 0.1e-4 m^2/s for middepth and surface waters. These values contrasts with the previous values of 1e-4 m^2/s first obtained by Munk 1966 and then by MW, and appear much closer to observational estimates of diapycnal mixing obtained by tracer release or microstructure measurements. We further show that the range of uncertainty in the above values is due to the nonlinearities of the equation of state for density.

  9. Satellite-based remote sensing of running water habitats at large riverscape scales: Tools to analyze habitat heterogeneity for river ecosystem management

    NASA Astrophysics Data System (ADS)

    Hugue, F.; Lapointe, M.; Eaton, B. C.; Lepoutre, A.

    2016-01-01

    We illustrate an approach to quantify patterns in hydraulic habitat composition and local heterogeneity applicable at low cost over very large river extents, with selectable reach window scales. Ongoing developments in remote sensing and geographical information science massively improve efficiencies in analyzing earth surface features. With the development of new satellite sensors and drone platforms and with the lowered cost of high resolution multispectral imagery, fluvial geomorphology is experiencing a revolution in mapping streams at high resolution. Exploiting the power of aerial or satellite imagery is particularly useful in a riverscape research framework (Fausch et al., 2002), where high resolution sampling of fluvial features and very large coverage extents are needed. This study presents a satellite remote sensing method that requires very limited field calibration data to estimate over various scales ranging from 1 m to many tens or river kilometers (i) spatial composition metrics for key hydraulic mesohabitat types and (ii) reach-scale wetted habitat heterogeneity indices such as the hydromorphological index of diversity (HMID). When the purpose is hydraulic habitat characterization applied over long river networks, the proposed method (although less accurate) is much less computationally expensive and less data demanding than two dimensional computational fluid dynamics (CFD). Here, we illustrate the tools based on a Worldview 2 satellite image of the Kiamika River, near Mont Laurier, Quebec, Canada, specifically over a 17-km river reach below the Kiamika dam. In the first step, a high resolution water depth (D) map is produced from a spectral band ratio (calculated from the multispectral image), calibrated with limited field measurements. Next, based only on known river discharge and estimated cross section depths at time of image capture, empirical-based pseudo-2D hydraulic rules are used to rapidly generate a two-dimensional map of flow velocity

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

    USGS Publications Warehouse

    Kirsch, Eileen M.

    1996-01-01

    Least terns (Sterna antillarum) were studied on the lower Platte River, Nebraska, where this endangered population nests on natural sandbar habitat and on sandpit sites created by gravel dredging adjacent to the river. Theoretically terns should select habitats according to habitat suitability. However, the introduction of sandpits and conversion of tallgrass prairies along the river banks to agriculture, residential, and wooded areas may have affected terns' abilities to distinguish suitable habitat or the suitability of nesting habitats in general. I examined habitat selection and productivity of least terns to determine if terns selected habitat according to suitability (as indicated by productivity), what factors affected habitat selection and productivity, and if estimated productivity could support this population. Available habitats of both types were characterized and quantified using aerial videography (1989-90), and habitat use was assessed from census data (1987-90). Productivity of adults and causes and correlates of egg and chick mortality were estimated (1987-90). Population trend was assessed with a deterministic model using my estimates of productivity and a range of survival estimates for Laridae reported in the literature. Terns tended to use river sites with large midstream sandbars and a wide channel, and large sandpit sites with large surface areas of water relative to unused sites on both habitats. Number of sites and area of sand available were estimated using discriminant function analysis of variables quantified from video scenes of both habitats. Terns apparently did not use all potentially available sandbar and sandpit sites because discriminant function factor scores for used and unused sites overlapped broadly for both habitats. Terns did not prefer 1 habitat over the other. Although proportions of available sites used were greater on sandpits than on the river, proportions of available sand used did not differ between habitats

  11. Assessing cumulative impacts of forest development on the distribution of furbearers using expert-based habitat modeling.

    PubMed

    Bridger, M C; Johnson, C J; Gillingham, M P

    2016-03-01

    Cumulative impacts of anthropogenic landscape change must be considered when managing and conserving wildlife habitat. Across the central-interior of British Columbia, Canada, industrial activities are altering the habitat of furbearer species. This region has witnessed unprecedented levels of anthropogenic landscape change following rapid development in a number of resource sectors, particularly forestry. Our objective was to create expert-based habitat models for three furbearer species: fisher (Pekania pennanti), Canada lynx (Lynx canadensis), and American marten (Martes americana) and quantify habitat change for those species. We recruited 10 biologist and 10 trapper experts and then used the analytical hierarchy process to elicit expert knowledge of habitat variables important to each species. We applied the models to reference landscapes (i.e., registered traplines) in two distinct study areas and then quantified the change in habitat availability from 1990 to 2013. There was strong agreement between expert groups in the choice of habitat variables and associated scores. Where anthropogenic impacts had increased considerably over the study period, the habitat models showed substantial declines in habitat availability for each focal species (78% decline in optimal fisher habitat, 83% decline in optimal lynx habitat, and 79% decline in optimal marten habitat). For those traplines with relatively little forest harvesting, the habitat models showed no substantial change in the availability of habitat over time. The results suggest that habitat for these three furbearer species declined significantly as a result of the cumulative impacts of forest harvesting. Results of this study illustrate the utility of expert knowledge for understanding large-scale patterns of habitat change over long time periods.

  12. Assessing cumulative impacts of forest development on the distribution of furbearers using expert-based habitat modeling.

    PubMed

    Bridger, M C; Johnson, C J; Gillingham, M P

    2016-03-01

    Cumulative impacts of anthropogenic landscape change must be considered when managing and conserving wildlife habitat. Across the central-interior of British Columbia, Canada, industrial activities are altering the habitat of furbearer species. This region has witnessed unprecedented levels of anthropogenic landscape change following rapid development in a number of resource sectors, particularly forestry. Our objective was to create expert-based habitat models for three furbearer species: fisher (Pekania pennanti), Canada lynx (Lynx canadensis), and American marten (Martes americana) and quantify habitat change for those species. We recruited 10 biologist and 10 trapper experts and then used the analytical hierarchy process to elicit expert knowledge of habitat variables important to each species. We applied the models to reference landscapes (i.e., registered traplines) in two distinct study areas and then quantified the change in habitat availability from 1990 to 2013. There was strong agreement between expert groups in the choice of habitat variables and associated scores. Where anthropogenic impacts had increased considerably over the study period, the habitat models showed substantial declines in habitat availability for each focal species (78% decline in optimal fisher habitat, 83% decline in optimal lynx habitat, and 79% decline in optimal marten habitat). For those traplines with relatively little forest harvesting, the habitat models showed no substantial change in the availability of habitat over time. The results suggest that habitat for these three furbearer species declined significantly as a result of the cumulative impacts of forest harvesting. Results of this study illustrate the utility of expert knowledge for understanding large-scale patterns of habitat change over long time periods. PMID:27209791

  13. Room to Live: the sizing of Lunar and Martian Habitats

    NASA Technical Reports Server (NTRS)

    McGregor, Walter L.

    2006-01-01

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

  14. Plant Habitat (PH)

    NASA Technical Reports Server (NTRS)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  15. Tracking changes and preventing loss in critical tiger habitat.

    PubMed

    Joshi, Anup R; Dinerstein, Eric; Wikramanayake, Eric; Anderson, Michael L; Olson, David; Jones, Benjamin S; Seidensticker, John; Lumpkin, Susan; Hansen, Matthew C; Sizer, Nigel C; Davis, Crystal L; Palminteri, Suzanne; Hahn, Nathan R

    2016-04-01

    The global population of wild tigers remains dangerously low at fewer than 3500 individuals. Habitat loss, along with poaching, can undermine the international target recovery of doubling the number of wild tigers by 2022. Using a new satellite-based monitoring system, we analyzed 14 years of forest loss data within the 76 landscapes (ranging from 278 to 269,983 km(2)) that have been prioritized for conservation of wild tigers. Our analysis provides an update of the status of tiger habitat and describes new applications of technology to detect precisely where forest loss is occurring in order to curb future habitat loss. Across the 76 landscapes, forest loss was far less than anticipated (79,597 ± 22,629 km(2), 7.7% of remaining habitat) over the 14-year study period (2001-2014). Habitat loss was unevenly distributed within a subset of 29 landscapes deemed most critical for doubling wild tiger populations: 19 showed little change (1.5%), whereas 10 accounted for more than 98% (57,392 ± 16,316 km(2)) of habitat loss. Habitat loss in source population sites within 76 landscapes ranged from no loss to 435 ± 124 km(2) ([Formula: see text], SD = 89, total = 1676 ± 476 km(2)). Doubling the tiger population by 2022 requires moving beyond tracking annual changes in habitat. We highlight near-real-time forest monitoring technologies that provide alerts of forest loss at relevant spatial and temporal scales to prevent further erosion. PMID:27051881

  16. Tracking changes and preventing loss in critical tiger habitat.

    PubMed

    Joshi, Anup R; Dinerstein, Eric; Wikramanayake, Eric; Anderson, Michael L; Olson, David; Jones, Benjamin S; Seidensticker, John; Lumpkin, Susan; Hansen, Matthew C; Sizer, Nigel C; Davis, Crystal L; Palminteri, Suzanne; Hahn, Nathan R

    2016-04-01

    The global population of wild tigers remains dangerously low at fewer than 3500 individuals. Habitat loss, along with poaching, can undermine the international target recovery of doubling the number of wild tigers by 2022. Using a new satellite-based monitoring system, we analyzed 14 years of forest loss data within the 76 landscapes (ranging from 278 to 269,983 km(2)) that have been prioritized for conservation of wild tigers. Our analysis provides an update of the status of tiger habitat and describes new applications of technology to detect precisely where forest loss is occurring in order to curb future habitat loss. Across the 76 landscapes, forest loss was far less than anticipated (79,597 ± 22,629 km(2), 7.7% of remaining habitat) over the 14-year study period (2001-2014). Habitat loss was unevenly distributed within a subset of 29 landscapes deemed most critical for doubling wild tiger populations: 19 showed little change (1.5%), whereas 10 accounted for more than 98% (57,392 ± 16,316 km(2)) of habitat loss. Habitat loss in source population sites within 76 landscapes ranged from no loss to 435 ± 124 km(2) ([Formula: see text], SD = 89, total = 1676 ± 476 km(2)). Doubling the tiger population by 2022 requires moving beyond tracking annual changes in habitat. We highlight near-real-time forest monitoring technologies that provide alerts of forest loss at relevant spatial and temporal scales to prevent further erosion.

  17. Vacant habitats in the Universe.

    PubMed

    Cockell, Charles S

    2011-02-01

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

  18. Spawning Habitat Studies of Hanford Reach Fall Chinook Salmon (Oncorhynchus tshawytscha), Final Report.

    SciTech Connect

    Geist, David R.; Arntzen, Evan V.; Chien, Yi-Ju

    2009-03-02

    agricultural and industrial development. In some cases, the riverbed is armored such that it is more difficult for spawners to move, while in other cases the intrusion of fine sediment into spawning gravels has reduced water flow to sensitive eggs and young fry. Recovery of fall Chinook salmon populations may involve habitat restoration through such actions as dam removal and reservoir drawdown. In addition, habitat protection will be accomplished through set-asides of existing high-quality habitat. A key component to evaluating these actions is quantifying the salmon spawning habitat potential of a given river reach so that realistic recovery goals for salmon abundance can be developed. Quantifying salmon spawning habitat potential requires an understanding of the spawning behavior of Chinook salmon, as well as an understanding of the physical habitat where these fish spawn. Increasingly, fish biologists are recognizing that assessing the physical habitat of riverine systems where salmon spawn goes beyond measuring microhabitat like water depth, velocity, and substrate size. Geomorphic features of the river measured over a range of spatial scales set up the physical template upon which the microhabitat develops, and successful assessments of spawning habitat potential incorporate these geomorphic features. We had three primary objectives for this study. The first objective was to determine the relationship between physical habitats at different spatial scales and fall Chinook salmon spawning locations. The second objective was to estimate the fall Chinook salmon redd capacity for the Reach. The third objective was to suggest a protocol for determining preferable spawning reaches of fall Chinook salmon. To ensure that we collected physical data within habitat that was representative of the full range of potential spawning habitat, the study area was stratified based on geomorphic features of the river using a two-dimensional river channel index that classified the river cross

  19. Deep Space Habitat Wireless Smart Plug

    NASA Technical Reports Server (NTRS)

    Morgan, Joseph A.; Porter, Jay; Rojdev, Kristina; Carrejo, Daniel B.; Colozza, Anthony J.

    2014-01-01

    NASA has been interested in technology development for deep space exploration, and one avenue of developing these technologies is via the eXploration Habitat (X-Hab) Academic Innovation Challenge. In 2013, NASA's Deep Space Habitat (DSH) project was in need of sensors that could monitor the power consumption of various devices in the habitat with added capability to control the power to these devices for load shedding in emergency situations. Texas A&M University's Electronic Systems Engineering Technology Program (ESET) in conjunction with their Mobile Integrated Solutions Laboratory (MISL) accepted this challenge, and over the course of 2013, several undergraduate students in a Capstone design course developed five wireless DC Smart Plugs for NASA. The wireless DC Smart Plugs developed by Texas A&M in conjunction with NASA's Deep Space Habitat team is a first step in developing wireless instrumentation for future flight hardware. This paper will further discuss the X-Hab challenge and requirements set out by NASA, the detailed design and testing performed by Texas A&M, challenges faced by the team and lessons learned, and potential future work on this design.

  20. Habitat Concepts for Deep Space Exploration

    NASA Technical Reports Server (NTRS)

    Smitherman, David; Griffin, Brand N.

    2014-01-01

    Future missions under consideration requiring human habitation beyond the International Space Station (ISS) include deep space habitats in the lunar vicinity to support asteroid retrieval missions, human and robotic lunar missions, satellite servicing, and Mars vehicle servicing missions. Habitat designs are also under consideration for missions beyond the Earth-Moon system, including transfers to near-Earth asteroids and Mars orbital destinations. A variety of habitat layouts have been considered, including those derived from the existing ISS designs and those that could be fabricated from the Space Launch System (SLS) propellant tanks. This paper presents a comparison showing several options for asteroid, lunar, and Mars mission habitats using ISS derived and SLS derived modules and identifies some of the advantages and disadvantages inherent in each. Key findings indicate that the larger SLS diameter modules offer built-in compatibility with the launch vehicle, single launch capability without on-orbit assembly, improved radiation protection, lighter structures per unit volume, and sufficient volume to accommodate consumables for long duration missions without resupply. The information provided with the findings includes mass and volume comparison data that should be helpful to future exploration mission planning efforts.

  1. Interspecific variation in hypoxia tolerance, swimming performance and plasticity in cyprinids that prefer different habitats.

    PubMed

    Fu, Shi-Jian; Fu, Cheng; Yan, Guan-Jie; Cao, Zhen-Dong; Zhang, An-Jie; Pang, Xu

    2014-02-15

    This study quantified and compared hypoxia tolerance and swim performance among cyprinid fish species from rapid-, slow- and intermediate-flow habitats (four species per habitat) in China. In addition, we explored the effects of short-term acclimation on swim performance, maximum metabolic rate (M(O2,max)) and gill remodelling to detect habitat-associated patterns of plastic response to hypoxia. Indices of hypoxia tolerance included oxygen threshold for loss of equilibrium (LOE50) and aquatic surface respiration (ASR50), and critical oxygen tension for routine metabolic rate (Pcrit). Critical swimming speed (Ucrit) and M(O2,max) were measured under normoxic and hypoxic conditions after 48 h acclimation to normoxia and hypoxia, and gill remodelling was estimated after 48 h of hypoxia exposure. Both traditional ANCOVA and phylogenetically independent contrast (PDANOVA) analyses showed that fish species from rapid-flow habitats exhibited lower LOE50 compared with fish from intermediate- and slow-flow habitats. Habitat-specific differences in Pcrit and Ucrit were detected using PDANOVA but not traditional ANCOVA analyses, with fish species from rapid-flow habitats exhibiting lower Pcrit but higher Ucrit values compared with fish from intermediate- and slow-flow habitats. Fish species from rapid-flow habitats were also characterized by less plasticity in swim performance and gill morphology in response to hypoxia acclimation compared with species from slow-flow habitats, but a greater drop in swim performance in response to acute hypoxia exposure. The study detected a habitat-specific difference in hypoxia tolerance, swimming performance and its plasticity among fish from habitats with different flow conditions, possibly because of the long-term adaptation to the habitat caused by selection stress. The PDANOVA analyses were more powerful than traditional statistical analyses according to the habitat effects in both hypoxia tolerance and swimming performance in this

  2. Coastal vertebrate exposure to predicted habitat changes due to sea level rise

    USGS Publications Warehouse

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel; Moore, Clinton; Cooper, Robert J.

    2015-01-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species’ fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species’ foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  3. Coastal Vertebrate Exposure to Predicted Habitat Changes Due to Sea Level Rise.

    PubMed

    Hunter, Elizabeth A; Nibbelink, Nathan P; Alexander, Clark R; Barrett, Kyle; Mengak, Lara F; Guy, Rachel K; Moore, Clinton T; Cooper, Robert J

    2015-12-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species' fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species' foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  4. Coastal Vertebrate Exposure to Predicted Habitat Changes Due to Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel K.; Moore, Clinton T.; Cooper, Robert J.

    2015-12-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species' fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species ( n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species' foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  5. Natural Propagation and Habitat Improvement, Volume I, Oregon, Supplement C, White River Habitat Inventory, 1983 Annual Report.

    SciTech Connect

    Heller, David

    1984-04-01

    More than 130 miles of stream fish habitat was inventoried and evaluated on the Mt. Hood National Forest during the first year of this multi-year project. First year tasks included field inventory and evaluation of habitat conditions on the White River and tributary streams thought to have the highest potential for supporting anadromous fish populations. All streams inventoried were located on the Mt. Hood National Forest. The surveyed area appears to contain most of the high quality anadromous fish habitat in the drainage. Habitat conditions appear suitable for steelhead, coho, and chinook salmon, and possibly sockeye. One hundred and twenty-four miles of potential anadromous fish habitat were identifed in the survey. Currently, 32 miles of this habitat would be readily accessible to anadromous fish. An additional 72 miles of habitat could be accessed with only minor passage improvement work. About 20 miles of habitat, however, will require major investment to provide fish passage. Three large lakes (Boulder, 14 acres; Badger, 45 acres; Clear, 550 acres) appear to be well-suited for rearing anadromous fish, although passage enhancement would be needed before self-sustaining runs could be established in any of the lakes.

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

    SciTech Connect

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

    2005-01-01

    Brine spills associated with petroleum extraction can reduce the amount of suitable habitat and increase habitat fragmentation for many terrestrial animals. We conducted a simulation study to quantify the effects of habitat loss and fragmentation on a solitary mammal predator. To provide focus, we adopted biological attributes of the American badger (Taxidea taxus) and environmental attributes of the Tallgrass Prairie Preserve in Oklahoma. We simulated badger activities on landscapes with different degrees of habitat loss and fragmentation using a spatially explicit and individual-based population model. Both habitat loss and fragmentation increased the incidence of habitat-related mortality and decreased the 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.

  7. Habitat Evaluation Procedures (HEP) Report; Calispell Creek Project, Technical Report 2004-2005.

    SciTech Connect

    Entz, Ray

    2005-02-01

    On July 13, 2004, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the Calispell Creek property, an acquisition completed by the Kalispel Tribe of Indians in February 2004. Evaluation species and appropriate models include Canada goose, mallard, muskrat, yellow warbler, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The Calispell Creek Project provides a total of 138.17 Habitat Units (HUs) for the species evaluated. Emergent wetland habitat provides 5.16 HUs for mallard and muskrat. Grassland provides 132.02 HUs for mallard and Canada goose. Scrub-shrub vegetation provides 0.99 HUs for yellow warbler and white-tailed deer. The objective of using HEP at the Calispell Creek Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  8. Effects of Mitigation Measures on Productivity of the White Sturgeon Populations in the Columbia River Downstream from McNary Dam, and Status and Habitat Requirements of White Sturgeon Populations in the Columbia and Snake Rivers Upstream from McNary Dam, 1992-1993 Annual Report.

    SciTech Connect

    Beamesdorfer, Raymond C.; Nigro, Anthony A.

    1993-12-01

    We report on our progress from April 1992-March 1993 in research on white sturgeon in the lower Columbia River. The study began in July 1986 and progress through 1992 was summarized in a comprehensive report in 2 volumes (Beamesderfer and Nigro 1993a, 1993b). This report details activities during the first year of Phase II of this sturgeon research. In Phase I, we assessed the status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam. Phase II will examine the effects on white sturgeon productivity of mitigative measures recommended in Phase I. The status and habitat requirements of white sturgeon populations upstream from McNary Dam will also be examined in Phase II. The study is a cooperative effort by the Oregon Department of Fish and Wildlife, Washington Department of Fisheries, U.S. Fish and Wildlife Service, and National Marine Fisheries Service. Work during the past year has focused on: (1) analysis of results of limited sampling conducted in 1992, (2) submission of Phase I results to the peer-review literature to ensure widespread dissemination, clarity of presentation, and credibility of findings, and (3) preparations for additional field work in 1993. In report sections A to D, each agency reports 1992 results if applicable and the current status of manuscripts. Results of field work conducted in 1993 will be reported in the 1994 annual report.

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

    USGS Publications Warehouse

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

    2003-01-01

    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.

  10. The influence of relative sediment supply on riverine habitat heterogeneity

    NASA Astrophysics Data System (ADS)

    Yarnell, Sarah M.; Mount, Jeffrey F.; Larsen, Eric W.

    2006-10-01

    The diversity of aquatic habitats in streams is linked to physical processes that act at various spatial and temporal scales. Two components of many that contribute to creating habitat heterogeneity in streams are the interaction between sediment supply and transport capacity and the presence of local in-stream structures, such as large woody debris and boulders. Data from previously published flume and field studies and a new field study on tributaries to the South Yuba River in Nevada County, California, USA, were used to evaluate the relationship between habitat heterogeneity, local in-stream structural features and relative sediment supply. Habitat heterogeneity was quantified using spatial heterogeneity measures from the field of landscape ecology. Relative sediment supply, as expressed by the sediment supply/transport capacity ratio, which controls channel morphology and substrate textures, two key physical habitat characteristics, was quantified using a dimensionless bedload transport ratio, q*. Calculated q* values were plotted against an ecologically meaningful heterogeneity index, Shannon's Diversity Index, measured for each study reach, as well as the percent area of in-stream structural elements. The results indicate two potential mechanisms for how relative sediment supply may drive geomorphic diversity in natural river systems at the reach scale. When less mobile structural elements form a small proportion of the reach landscape, the supply/capacity ratio dictates the range of sediment textures and geomorphic features observed within the reach. In these settings, channels with a moderate relative sediment supply exhibit the highest textural and geomorphic diversity. In contrast, when less mobile structural elements are abundant, forced local scour and deposition creates high habitat heterogeneity, even in the presence of high relative sediment supply.

  11. Habitat-mediated timing of migration in polar bears: an individual perspective.

    PubMed

    Cherry, Seth G; Derocher, Andrew E; Lunn, Nicholas J

    2016-07-01

    Migration phenology is largely determined by how animals respond to seasonal changes in environmental conditions. Our perception of the relationship between migratory behavior and environmental cues can vary depending on the spatial scale at which these interactions are measured. Understanding the behavioral mechanisms behind population-scale movements requires knowledge of how individuals respond to local cues. We show how time-to-event models can be used to predict what factors are associated with the timing of an individual's migratory behavior using data from GPS collared polar bears (Ursus maritimus) that move seasonally between sea ice and terrestrial habitats. We found the concentration of sea ice that bears experience at a local level, along with the duration of exposure to these conditions, was most associated with individual migration timing. Our results corroborate studies that assume thresholds of >50% sea ice concentration are necessary for suitable polar bear habitat; however, continued periods (e.g., days to weeks) of exposure to suboptimal ice concentrations during seasonal melting were required before the proportion of bears migrating to land increased substantially. Time-to-event models are advantageous for examining individual movement patterns because they account for the idea that animals make decisions based on an accumulation of knowledge from the landscapes they move through and not simply the environment they are exposed to at the time of a decision. Understanding the migration behavior of polar bears moving between terrestrial and marine habitat, at multiple spatiotemporal scales, will be a major aspect of quantifying observed and potential demographic responses to climate-induced environmental changes. PMID:27547331

  12. Scale-dependent habitat use in three species of prairie wetland birds

    USGS Publications Warehouse

    Naugle, D.E.; Higgins, K.F.; Nusser, S.M.; Johnson, W.C.

    1999-01-01

    We evaluated the influence of scale on habitat use for three wetland-obligate bird species with divergent life history characteristics and possible scale-dependent criteria for nesting and foraging in South Dakota, USA. A stratified, two-stage cluster sample was used to randomly select survey wetlands within strata defined by region, wetland density, and wetland surface area. We used 18-m (0.1 ha) fixed radius circular-plots to survey birds in 412 semipermanent wetlands during the summers of 1995 and 1996. Variation in habitat use by pied-billed grebes (Podilymbus podiceps) and yellow-headed blackbirds (Xanthocephalus xanthocephalus), two sedentary species that rarely exploit resources outside the vicinity of nest wetlands, was explained solely by within-patch variation. Yellow-headed blackbirds were a cosmopolitan species that commonly nested in small wetlands, whereas pied-billed grebes were an area-sensitive species that used larger wetlands regardless of landscape pattern. Area requirements for black terns (Chlidonias niger), a vagile species that typically forages up to 4 km away from the nest wetland, fluctuated in response to landscape structure. Black tern area requirements were small (6.5 ha) in heterogeneous landscapes compared to those in homogeneous landscapes (15.4-32.6 ha). Low wetland density landscapes composed of small wetlands, where few nesting wetlands occurred and potential food sources were spread over large distances, were not widely used by black terns. Landscape-level measurements related to black tern occurrence extended past relationships between wetlands into the surrounding matrix. Black terns were more likely to occur in landscapes where grasslands had not been tilled for agricultural production. Our findings represent empirical evidence that characteristics of entire landscapes, rather than individual patches, must be quantified to assess habitat suitability for wide-ranging species that use resources over large areas.

  13. Habitat-mediated timing of migration in polar bears: an individual perspective.

    PubMed

    Cherry, Seth G; Derocher, Andrew E; Lunn, Nicholas J

    2016-07-01

    Migration phenology is largely determined by how animals respond to seasonal changes in environmental conditions. Our perception of the relationship between migratory behavior and environmental cues can vary depending on the spatial scale at which these interactions are measured. Understanding the behavioral mechanisms behind population-scale movements requires knowledge of how individuals respond to local cues. We show how time-to-event models can be used to predict what factors are associated with the timing of an individual's migratory behavior using data from GPS collared polar bears (Ursus maritimus) that move seasonally between sea ice and terrestrial habitats. We found the concentration of sea ice that bears experience at a local level, along with the duration of exposure to these conditions, was most associated with individual migration timing. Our results corroborate studies that assume thresholds of >50% sea ice concentration are necessary for suitable polar bear habitat; however, continued periods (e.g., days to weeks) of exposure to suboptimal ice concentrations during seasonal melting were required before the proportion of bears migrating to land increased substantially. Time-to-event models are advantageous for examining individual movement patterns because they account for the idea that animals make decisions based on an accumulation of knowledge from the landscapes they move through and not simply the environment they are exposed to at the time of a decision. Understanding the migration behavior of polar bears moving between terrestrial and marine habitat, at multiple spatiotemporal scales, will be a major aspect of quantifying observed and potential demographic responses to climate-induced environmental changes.

  14. Quantification of fish habitat in selected reaches of the Marmaton and Marais des Cygnes Rivers, Missouri

    USGS Publications Warehouse

    Heimann, David C.; Richards, Joseph M.; Brewer, Shannon K.; Norman, Richard D.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Conservation, undertook a study to quantify fish habitat by using relations between streamflow and the spatial and temporal distributions of fish habitat at five sites in the Marmaton and Marais des Cygnes Rivers in western Missouri. Twenty-six fish habitat categories were selected for nine species under varying seasonal (spring, summer, and fall), diel (summer day and night), and life-stage (spawning, juvenile, and adult) conditions. Physical habitat characteristics were determined for each category using depth, velocity, and channel substrate criteria. Continuous streamflow data were then combined with the habitat-streamflow relations to compile a habitat time series for each habitat category at each site. Fish habitat categories were assessed as to their vulnerability to habitat alteration based on critical life stages (spawning and juvenile rearing periods) and susceptibility to habitat limitations from dewatering or high flows. Species categories representing critical life stages with physical habitat limitations represent likely bottlenecks in fish populations. Categories with potential bottlenecks can serve as indicator categories and aid managers when determining the flows necessary for maintaining these habitats under altered flow regimes. The relation between the area of each habitat category and streamflow differed greatly between category, season, and stream reach. No single flow maximized selected habitat area for all categories or even for all species/category within a particular season at a site. However, some similarities were noted among habitat characteristics, including the streamflow range for which habitat availability is maximized and the range of streamflows for which a habitat category area is available at the Marmaton River sites. A monthly habitat time series was created for all 26 habitat categories at two Marmaton River sites. A daily habitat time series was

  15. Workstation Designs for a Cis-Lunar Deep Space Habitat

    NASA Technical Reports Server (NTRS)

    Howe, A. Scott

    2014-01-01

    Using the International Standard Payload Rack (ISPR) system, a suite of workstations required for deep space missions have been proposed to fill out habitation functions in an International Space Station (ISS) derived Cis-lunar Deep Space Habitat. This paper introduces the functional layout of the Cis-lunar habitat design, and describes conceptual designs for modular deployable work surfaces, General Maintenance Workstation (GMWS), In-Space Manufacturing Workstation (ISMW), Intra-Vehicular Activity Telerobotics Work Station (IVA-TRWS), and Galley / Wardroom.

  16. Occupancy in continuous habitat

    USGS Publications Warehouse

    Efford, Murray G.; Dawson, Deanna K.

    2012-01-01

    The probability that a site has at least one individual of a species ('occupancy') has come to be widely used as a state variable for animal population monitoring. The available statistical theory for estimation when detection is imperfect applies particularly to habitat patches or islands, although it is also used for arbitrary plots in continuous habitat. The probability that such a plot is occupied depends on plot size and home-range characteristics (size, shape and dispersion) as well as population density. Plot size is critical to the definition of occupancy as a state variable, but clear advice on plot size is missing from the literature on the design of occupancy studies. We describe models for the effects of varying plot size and home-range size on expected occupancy. Temporal, spatial, and species variation in average home-range size is to be expected, but information on home ranges is difficult to retrieve from species presence/absence data collected in occupancy studies. The effect of variable home-range size is negligible when plots are very large (>100 x area of home range), but large plots pose practical problems. At the other extreme, sampling of 'point' plots with cameras or other passive detectors allows the true 'proportion of area occupied' to be estimated. However, this measure equally reflects home-range size and density, and is of doubtful value for population monitoring or cross-species comparisons. Plot size is ill-defined and variable in occupancy studies that detect animals at unknown distances, the commonest example being unlimited-radius point counts of song birds. We also find that plot size is ill-defined in recent treatments of "multi-scale" occupancy; the respective scales are better interpreted as temporal (instantaneous and asymptotic) rather than spatial. Occupancy is an inadequate metric for population monitoring when it is confounded with home-range size or detection distance.

  17. Quantifying Poststroke Apathy With Actimeters.

    PubMed

    Goldfine, Andrew M; Dehbandi, Behdad; Kennedy, Juliana M; Sabot, Briana; Semper, Cory; Putrino, David

    2016-01-01

    The authors tested the hypothesis that wrist-worn actimeters can quantify the severity of poststroke apathy. The authors studied 57 patients admitted to an acute rehabilitation unit for ischemic or hemorrhagic stroke. After accounting for motor deficit of the affected arm and accounting for age, each increment of the Apathy Inventory score correlated with 5.6 fewer minutes of moving per hour. The overall statistical model had an R(2) of only 0.34, suggesting unexplained factors for total movement time. Wrist-worn actimeters may serve as an objective, quantifiable measure of poststroke apathy in patients with an intact upper extremity but cannot be used alone to diagnose apathy. PMID:26900735

  18. Quantifying and measuring cyber resiliency

    NASA Astrophysics Data System (ADS)

    Cybenko, George

    2016-05-01

    Cyber resliency has become an increasingly attractive research and operational concept in cyber security. While several metrics have been proposed for quantifying cyber resiliency, a considerable gap remains between those metrics and operationally measurable and meaningful concepts that can be empirically determined in a scientific manner. This paper describes a concrete notion of cyber resiliency that can be tailored to meet specific needs of organizations that seek to introduce resiliency into their assessment of their cyber security posture.

  19. Natural regeneration in two central Idaho grand fir habitat types. Forest Service research paper

    SciTech Connect

    Geier-Hayes, K.

    1994-03-01

    Natural regeneration of five conifer species was surveyed in two central Idaho grand fir habitat types. The habitat types range from warm, dry (grand fir/white spirea) to mesic (Grand fir/Mountain Maple). Four harvest-regeneration methods and four site preparation techniques were sampled. Recommendations for obtaining natural regeneration vary primarily by habitat type. Conifer seedlings in the warm, dry grand fir white spirea habitat type require site protection for establishment. In the mesic grand fir/mountain maple habitat type, tall shrub potential can reduce the opportunity to establish early seral conifer species.

  20. Concepts for a Shroud or Propellant Tank Derived Deep Space Habitat

    NASA Technical Reports Server (NTRS)

    Howard, Robert L.

    2012-01-01

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

  1. Using otolith chemical and structural analysis to investigate reservoir habitat use by juvenile Chinook salmon Oncorhynchus tshawytscha.

    PubMed

    Bourret, S L; Kennedy, B P; Caudill, C C; Chittaro, P M

    2014-11-01

    Isotopic composition of (87) Sr:(86) Sr and natural elemental tracers (Sr, Ba, Mg, Mn and Ca) were quantified from otoliths in juvenile and adult Chinook salmon Oncorhynchus tshawytscha to assess the ability of otolith microchemistry and microstructure to reconstruct juvenile O. tshawytscha rearing habitat and growth. Daily increments were measured to assess relative growth between natal rearing habitats. Otolith microchemistry was able to resolve juvenile habitat use between reservoir and natal tributary rearing habitats (within headwater basins), but not among catchments. Results suggest that 90% (n = 18) of sampled non-hatchery adults returning to the Middle Fork Willamette River were reared in a reservoir and 10% (n = 2) in natal tributary habitat upstream from the reservoir. Juveniles collected in reservoirs had higher growth rates than juveniles reared in natal streams. The results demonstrate the utility of otolith microchemistry and microstructure to distinguish among rearing habitats, including habitats in highly altered systems. PMID:25229130

  2. A Wildlife Habitat Improvement Plan.

    ERIC Educational Resources Information Center

    Rogers, S. Elaine

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

  3. Clay Animals and Their Habitats

    ERIC Educational Resources Information Center

    Adamson, Kay

    2010-01-01

    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…

  4. Saving Salmon Through Advances in Fluvial Remote Sensing: Applying the Optimal Band Ratio Analysis (OBRA) for Bathymetric Mapping of Over 250 km of River Channel and Habitat Classification

    NASA Astrophysics Data System (ADS)

    Richardson, R.; Legleiter, C. J.; Harrison, L.

    2015-12-01

    Salmonids are threatened with extinction across the world from the fragmentation of riverine ecosystems from dams and diversions. In California, efforts to expand the range of spawnable habitat for native salmon by transporting fish around reservoirs is a potentially species saving idea. But, strong scientific evidence of the amount of high quality habitat is required to make these difficult management decisions. Remote sensing has long been used in fluvial settings to identify physical parameters that drive the quality of aquatic habitat; however, the true strength of remote sensing to cover large spatial extents has not been applied with the resolution that is relevant to salmonids. This project utilizes hyperspectral data of over 250 km of the Tuolumne and Merced Rivers to extract depth and bed slope from the wetted channel and NIR LiDAR for the surrounding topography. The Optimal Band Ratio Analysis (OBRA) has proven as an effective tool to create bathymetric maps of river channels in ideal settings with clear water, high amounts of bottom reflectance, and less than 3 meters deep over short distances. Results from this study show that OBRA can be applied over larger riverscapes at high resolutions (0.5 m). The depth and bed slope estimations are used to classify habitat units that are crucial to quantifying the quality and amount of habitat in these river that once produced large populations of native salmonids. As more managers look to expand habitat for these threatened species the tools developed here will be cost effective over the large extents that salmon migrate to spawn.

  5. The impacts of mobile fishing gear on seafloor habitats in the gulf of maine (Northwest Atlantic): Implications for conservation of fish populations

    USGS Publications Warehouse

    Auster, P.J.; Malatesta, R.J.; Langton, R.W.; Watling, Les; Valentine, P.C.; Donaldson, C.L.S.; Langton, E.W.; Shepard, A.N.; Babb, Ivar G.

    1996-01-01

    Fishing gear alters seafloor habitats, but the extent of these alterations, and their effects, have not been quantified extensively in the northwest Atlantic. Understanding the extent of these impacts, and their effects on populations of living marine resources, is needed to properly manage current and future levels of fishing effort and fishing power. For example, the entire U.S. side of the Gulf of Maine was impacted annually by mobile fishing gear between 1984 and 1990, based on calculations of area swept by trawl and dredge gear. Georges Bank was impacted three to nearly four times annually during the same period. Studies at three sites in the Gulf of Maine (off Swans Island, Jeffreys Bank, and Stellwagen Bank) showed that mobile fishing gear altered the physical structure (=complexity) of benthic habitats. Complexity was reduced by direct removal of biogenic (e.g., sponges, hydrozoans, bryozoans, amphipod tubes, holothurians, shell aggregates) and sedimentary (e.g., sand waves, depressions) structures. Also, removal of organisms that create structures (e.g., crabs, scallops) indirectly reduced complexity. Reductions in habitat complexity may lead to increased predation on juveniles of harvested species and ultimately recruitment to the harvestable stock. Because of a lack of reference sites, where use of mobile fishing is prohibited, no empirical studies have yet been conducted on a scale that could demonstrate population level effects of habitat-management options. If marine fisheries management is to evolve toward an ecosystem or habitat management approach, experiments are required on the effects of habitat change, both anthropogenic and natural.

  6. The shark assemblage at French Frigate Shoals atoll, Hawai'i: species composition, abundance and habitat use.

    PubMed

    Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G

    2011-01-01

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling. PMID:21347321

  7. The Shark Assemblage at French Frigate Shoals Atoll, Hawai‘i: Species Composition, Abundance and Habitat Use

    PubMed Central

    Dale, Jonathan J.; Stankus, Austin M.; Burns, Michael S.; Meyer, Carl G.

    2011-01-01

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao Mh ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289–1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling. PMID:21347321

  8. The shark assemblage at French Frigate Shoals atoll, Hawai'i: species composition, abundance and habitat use.

    PubMed

    Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G

    2011-02-10

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling.

  9. Lunar Surface Habitat Configuration Assessment: Methodology and Observations

    NASA Technical Reports Server (NTRS)

    Carpenter, Amanda

    2008-01-01

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

  10. Density-dependent habitat selection and partitioning between two sympatric ungulates.

    PubMed

    van Beest, Floris M; McLoughlin, Philip D; Vander Wal, Eric; Brook, Ryan K

    2014-08-01

    Theory on density-dependent habitat selection predicts that as population density of a species increases, use of higher quality (primary) habitat by individuals declines while use of lower quality (secondary) habitat rises. Habitat partitioning is often considered the primary mechanism for coexistence between similar species, but how this process evolves with changes in population density remains to be empirically tested for free-ranging ungulates. We used resource-selection functions to quantify density effects on landscape-scale habitat selection of two sympatric species of ungulates [moose (Alces alces) and elk (Cervus canadensis manitobensis)] in Riding Mountain National Park, Manitoba, Canada (2000-2011). The density of elk was actively reduced from 1.2 to 0.4 elk km(-2) through increased hunting effort during the period of study, while moose density decreased without additional human influence from 1.6-0.7 moose km(-2). Patterns of habitat selection during winter by both species changed in accordance to expectations from density-dependent habitat-selection theory. At low intraspecific density, moose and elk did not partition habitat, as both species selected strongly for mixed forest (primary habitat providing both food and cover), but did so in different areas segregated across an elevational gradient. As intraspecific density increased, selection for primary habitat by both species decreased, while selection for secondary, lower quality habitat such as agricultural fields (for elk) and built-up areas (for moose) increased. We show that habitat-selection strategies during winter for moose and elk, and subsequent effects on habitat partitioning, depend heavily on the position in state space (density) of both species.

  11. Weather Conditions Drive Dynamic Habitat Selection in a Generalist Predator

    PubMed Central

    Sunde, Peter; Thorup, Kasper; Jacobsen, Lars B.; Rahbek, Carsten

    2014-01-01

    Despite the dynamic nature of habitat selection, temporal variation as arising from factors such as weather are rarely quantified in species-habitat relationships. We analysed habitat use and selection (use/availability) of foraging, radio-tagged little owls (Athene noctua), a nocturnal, year-round resident generalist predator, to see how this varied as a function of weather, season and availability. Use of the two most frequently used land cover types, gardens/buildings and cultivated fields varied more than 3-fold as a simple function of season and weather through linear effects of wind and quadratic effects of temperature. Even when controlling for the temporal context, both land cover types were used more evenly than predicted from variation in availability (functional response in habitat selection). Use of two other land cover categories (pastures and moist areas) increased linearly with temperature and was proportional to their availability. The study shows that habitat selection by generalist foragers may be highly dependent on temporal variables such as weather, probably because such foragers switch between weather dependent feeding opportunities offered by different land cover types. An opportunistic foraging strategy in a landscape with erratically appearing feeding opportunities in different land cover types, may possibly also explain decreasing selection of the two most frequently used land cover types with increasing availability. PMID:24516615

  12. Weather conditions drive dynamic habitat selection in a generalist predator.

    PubMed

    Sunde, Peter; Thorup, Kasper; Jacobsen, Lars B; Rahbek, Carsten

    2014-01-01

    Despite the dynamic nature of habitat selection, temporal variation as arising from factors such as weather are rarely quantified in species-habitat relationships. We analysed habitat use and selection (use/availability) of foraging, radio-tagged little owls (Athene noctua), a nocturnal, year-round resident generalist predator, to see how this varied as a function of weather, season and availability. Use of the two most frequently used land cover types, gardens/buildings and cultivated fields varied more than 3-fold as a simple function of season and weather through linear effects of wind and quadratic effects of temperature. Even when controlling for the temporal context, both land cover types were used more evenly than predicted from variation in availability (functional response in habitat selection). Use of two other land cover categories (pastures and moist areas) increased linearly with temperature and was proportional to their availability. The study shows that habitat selection by generalist foragers may be highly dependent on temporal variables such as weather, probably because such foragers switch between weather dependent feeding opportunities offered by different land cover types. An opportunistic foraging strategy in a landscape with erratically appearing feeding opportunities in different land cover types, may possibly also explain decreasing selection of the two most frequently used land cover types with increasing availability.

  13. Tundra swan habitat preferences during migration in North Dakota

    USGS Publications Warehouse

    Earnst, S.L.

    1994-01-01

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

  14. Defining critical habitats of threatened and endemic reef fishes with a multivariate approach.

    PubMed

    Purcell, Steven W; Clarke, K Robert; Rushworth, Kelvin; Dalton, Steven J

    2014-12-01

    Understanding critical habitats of threatened and endemic animals is essential for mitigating extinction risks, developing recovery plans, and siting reserves, but assessment methods are generally lacking. We evaluated critical habitats of 8 threatened or endemic fish species on coral and rocky reefs of subtropical eastern Australia, by measuring physical and substratum-type variables of habitats at fish sightings. We used nonmetric and metric multidimensional scaling (nMDS, mMDS), Analysis of similarities (ANOSIM), similarity percentages analysis (SIMPER), permutational analysis of multivariate dispersions (PERMDISP), and other multivariate tools to distinguish critical habitats. Niche breadth was widest for 2 endemic wrasses, and reef inclination was important for several species, often found in relatively deep microhabitats. Critical habitats of mainland reef species included small caves or habitat-forming hosts such as gorgonian corals and black coral trees. Hard corals appeared important for reef fishes at Lord Howe Island, and red algae for mainland reef fishes. A wide range of habitat variables are required to assess critical habitats owing to varied affinities of species to different habitat features. We advocate assessments of critical habitats matched to the spatial scale used by the animals and a combination of multivariate methods. Our multivariate approach furnishes a general template for assessing the critical habitats of species, understanding how these vary among species, and determining differences in the degree of habitat specificity.

  15. The integration of climate change, spatial dynamics, and habitat fragmentation: A conceptual overview.

    PubMed

    Holyoak, Marcel; Heath, Sacha K

    2016-01-01

    A growing number of studies have looked at how climate change alters the effects of habitat fragmentation and degradation on both single and multiple species; some raise concern that biodiversity loss and its effects will be exacerbated. The published literature on spatial dynamics (such as dispersal and metapopulation dynamics), habitat fragmentation and climate change requires synthesis and a conceptual framework to simplify thinking. We propose a framework that integrates how climate change affects spatial population dynamics and the effects of habitat fragmentation in terms of: (i) habitat quality, quantity and distribution; (ii) habitat connectivity; and (iii) the dynamics of habitat itself. We use the framework to categorize existing autecological studies and investigate how each is affected by anthropogenic climate change. It is clear that a changing climate produces changes in the geographic distribution of climatic conditions, and the amount and quality of habitat. The most thorough published studies show how such changes impact metapopulation persistence, source-sink dynamics, changes in species' geographic range and community composition. Climate-related changes in movement behavior and quantity, quality and distribution of habitat have also produced empirical changes in habitat connectivity for some species. An underexplored area is how habitat dynamics that are driven by climatic processes will affect species that live in dynamic habitats. We end our discussion by suggesting ways to improve current attempts to integrate climate change, spatial population dynamics and habitat fragmentation effects, and suggest distinct areas of study that might provide opportunities for more fully integrative work.

  16. The integration of climate change, spatial dynamics, and habitat fragmentation: A conceptual overview.

    PubMed

    Holyoak, Marcel; Heath, Sacha K

    2016-01-01

    A growing number of studies have looked at how climate change alters the effects of habitat fragmentation and degradation on both single and multiple species; some raise concern that biodiversity loss and its effects will be exacerbated. The published literature on spatial dynamics (such as dispersal and metapopulation dynamics), habitat fragmentation and climate change requires synthesis and a conceptual framework to simplify thinking. We propose a framework that integrates how climate change affects spatial population dynamics and the effects of habitat fragmentation in terms of: (i) habitat quality, quantity and distribution; (ii) habitat connectivity; and (iii) the dynamics of habitat itself. We use the framework to categorize existing autecological studies and investigate how each is affected by anthropogenic climate change. It is clear that a changing climate produces changes in the geographic distribution of climatic conditions, and the amount and quality of habitat. The most thorough published studies show how such changes impact metapopulation persistence, source-sink dynamics, changes in species' geographic range and community composition. Climate-related changes in movement behavior and quantity, quality and distribution of habitat have also produced empirical changes in habitat connectivity for some species. An underexplored area is how habitat dynamics that are driven by climatic processes will affect species that live in dynamic habitats. We end our discussion by suggesting ways to improve current attempts to integrate climate change, spatial population dynamics and habitat fragmentation effects, and suggest distinct areas of study that might provide opportunities for more fully integrative work. PMID:26458303

  17. Defining critical habitats of threatened and endemic reef fishes with a multivariate approach.

    PubMed

    Purcell, Steven W; Clarke, K Robert; Rushworth, Kelvin; Dalton, Steven J

    2014-12-01

    Understanding critical habitats of threatened and endemic animals is essential for mitigating extinction risks, developing recovery plans, and siting reserves, but assessment methods are generally lacking. We evaluated critical habitats of 8 threatened or endemic fish species on coral and rocky reefs of subtropical eastern Australia, by measuring physical and substratum-type variables of habitats at fish sightings. We used nonmetric and metric multidimensional scaling (nMDS, mMDS), Analysis of similarities (ANOSIM), similarity percentages analysis (SIMPER), permutational analysis of multivariate dispersions (PERMDISP), and other multivariate tools to distinguish critical habitats. Niche breadth was widest for 2 endemic wrasses, and reef inclination was important for several species, often found in relatively deep microhabitats. Critical habitats of mainland reef species included small caves or habitat-forming hosts such as gorgonian corals and black coral trees. Hard corals appeared important for reef fishes at Lord Howe Island, and red algae for mainland reef fishes. A wide range of habitat variables are required to assess critical habitats owing to varied affinities of species to different habitat features. We advocate assessments of critical habitats matched to the spatial scale used by the animals and a combination of multivariate methods. Our multivariate approach furnishes a general template for assessing the critical habitats of species, understanding how these vary among species, and determining differences in the degree of habitat specificity. PMID:25302855

  18. Linking occurrence and fitness to persistence: habitat-based approach for endangered greater sage-grouse.

    PubMed

    Aldridge, Cameron L; Boyce, Mark S

    2007-03-01

    Detailed empirical models predicting both species occurrence and fitness across a landscape are necessary to understand processes related to population persistence. Failure to consider both occurrence and fitness may result in incorrect assessments of habitat importance leading to inappropriate management strategies. We took a two-stage approach to identifying critical nesting and brood-rearing habitat for the endangered Greater Sage-Grouse (Centrocercus urophasianus) in Alberta at a landscape scale. First, we used logistic regression to develop spatial models predicting the relative probability of use (occurrence) for Sage-Grouse nests and broods. Secondly, we used Cox proportional hazards survival models to identify the most risky habitats across the landscape. We combined these two approaches to identify Sage-Grouse habitats that pose minimal risk of failure (source habitats) and attractive sink habitats that pose increased risk (ecological traps). Our models showed that Sage-Grouse select for heterogeneous patches of moderate sagebrush cover (quadratic relationship) and avoid anthropogenic edge habitat for nesting. Nests were more successful in heterogeneous habitats, but nest success was independent of anthropogenic features. Similarly, broods selected heterogeneous high-productivity habitats with sagebrush while avoiding human developments, cultivated cropland, and high densities of oil wells. Chick mortalities tended to occur in proximity to oil and gas developments and along riparian habitats. For nests and broods, respectively, approximately 10% and 5% of the study area was considered source habitat, whereas 19% and 15% of habitat was attractive sink habitat. Limited source habitats appear to be the main reason for poor nest success (39%) and low chick survival (12%). Our habitat models identify areas of protection priority and areas that require immediate management attention to enhance recruitment to secure the viability of this population. This novel

  19. Linking occurrence and fitness to persistence: Habitat-based approach for endangered Greater Sage-Grouse

    USGS Publications Warehouse

    Aldridge, C.L.; Boyce, M.S.

    2007-01-01

    Detailed empirical models predicting both species occurrence and fitness across a landscape are necessary to understand processes related to population persistence. Failure to consider both occurrence and fitness may result in incorrect assessments of habitat importance leading to inappropriate management strategies. We took a two-stage approach to identifying critical nesting and brood-rearing habitat for the endangered Greater Sage-Grouse (Centrocercus urophasianus) in Alberta at a landscape scale. First, we used logistic regression to develop spatial models predicting the relative probability of use (occurrence) for Sage-Grouse nests and broods. Secondly, we used Cox proportional hazards survival models to identify the most risky habitats across the landscape. We combined these two approaches to identify Sage-Grouse habitats that pose minimal risk of failure (source habitats) and attractive sink habitats that pose increased risk (ecological traps). Our models showed that Sage-Grouse select for heterogeneous patches of moderate sagebrush cover (quadratic relationship) and avoid anthropogenic edge habitat for nesting. Nests were more successful in heterogeneous habitats, but nest success was independent of anthropogenic features. Similarly, broods selected heterogeneous high-productivity habitats with sagebrush while avoiding human developments, cultivated cropland, and high densities of oil wells. Chick mortalities tended to occur in proximity to oil and gas developments and along riparian habitats. For nests and broods, respectively, approximately 10% and 5% of the study area was considered source habitat, whereas 19% and 15% of habitat was attractive sink habitat. Limited source habitats appear to be the main reason for poor nest success (39%) and low chick survival (12%). Our habitat models identify areas of protection priority and areas that require immediate management attention to enhance recruitment to secure the viability of this population. This novel

  20. Habitat-based cetacean density models for the U.S. Atlantic and Gulf of Mexico.

    PubMed

    Roberts, Jason J; Best, Benjamin D; Mannocci, Laura; Fujioka, Ei; Halpin, Patrick N; Palka, Debra L; Garrison, Lance P; Mullin, Keith D; Cole, Timothy V N; Khan, Christin B; McLellan, William A; Pabst, D Ann; Lockhart, Gwen G

    2016-01-01

    Cetaceans are protected worldwide but vulnerable to incidental harm from an expanding array of human activities at sea. Managing potential hazards to these highly-mobile populations increasingly requires a detailed understanding of their seasonal distributions and habitats. Pursuant to the urgent need for this knowledge for the U.S. Atlantic and Gulf of Mexico, we integrated 23 years of aerial and shipboard cetacean surveys, linked them to environmental covariates obtained from remote sensing and ocean models, and built habitat-based density models for 26 species and 3 multi-species guilds using distance sampling methodology. In the Atlantic, for 11 well-known species, model predictions resembled seasonal movement patterns previously suggested in the literature. For these we produced monthly mean density maps. For lesser-known taxa, and in the Gulf of Mexico, where seasonal movements were less well described, we produced year-round mean density maps. The results revealed high regional differences in small delphinoid densities, confirmed the importance of the continental slope to large delphinoids and of canyons and seamounts to beaked and sperm whales, and quantified seasonal shifts in the densities of migratory baleen whales. The density maps, freely available online, are the first for these regions to be published in the peer-reviewed literature. PMID:26936335

  1. Habitat-based cetacean density models for the U.S. Atlantic and Gulf of Mexico

    PubMed Central

    Roberts, Jason J.; Best, Benjamin D.; Mannocci, Laura; Fujioka, Ei; Halpin, Patrick N.; Palka, Debra L.; Garrison, Lance P.; Mullin, Keith D.; Cole, Timothy V. N.; Khan, Christin B.; McLellan, William A.; Pabst, D. Ann; Lockhart, Gwen G.

    2016-01-01

    Cetaceans are protected worldwide but vulnerable to incidental harm from an expanding array of human activities at sea. Managing potential hazards to these highly-mobile populations increasingly requires a detailed understanding of their seasonal distributions and habitats. Pursuant to the urgent need for this knowledge for the U.S. Atlantic and Gulf of Mexico, we integrated 23 years of aerial and shipboard cetacean surveys, linked them to environmental covariates obtained from remote sensing and ocean models, and built habitat-based density models for 26 species and 3 multi-species guilds using distance sampling methodology. In the Atlantic, for 11 well-known species, model predictions resembled seasonal movement patterns previously suggested in the literature. For these we produced monthly mean density maps. For lesser-known taxa, and in the Gulf of Mexico, where seasonal movements were less well described, we produced year-round mean density maps. The results revealed high regional differences in small delphinoid densities, confirmed the importance of the continental slope to large delphinoids and of canyons and seamounts to beaked and sperm whales, and quantified seasonal shifts in the densities of migratory baleen whales. The density maps, freely available online, are the first for these regions to be published in the peer-reviewed literature. PMID:26936335

  2. Habitat-based cetacean density models for the U.S. Atlantic and Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Roberts, Jason J.; Best, Benjamin D.; Mannocci, Laura; Fujioka, Ei; Halpin, Patrick N.; Palka, Debra L.; Garrison, Lance P.; Mullin, Keith D.; Cole, Timothy V. N.; Khan, Christin B.; McLellan, William A.; Pabst, D. Ann; Lockhart, Gwen G.

    2016-03-01

    Cetaceans are protected worldwide but vulnerable to incidental harm from an expanding array of human activities at sea. Managing potential hazards to these highly-mobile populations increasingly requires a detailed understanding of their seasonal distributions and habitats. Pursuant to the urgent need for this knowledge for the U.S. Atlantic and Gulf of Mexico, we integrated 23 years of aerial and shipboard cetacean surveys, linked them to environmental covariates obtained from remote sensing and ocean models, and built habitat-based density models for 26 species and 3 multi-species guilds using distance sampling methodology. In the Atlantic, for 11 well-known species, model predictions resembled seasonal movement patterns previously suggested in the literature. For these we produced monthly mean density maps. For lesser-known taxa, and in the Gulf of Mexico, where seasonal movements were less well described, we produced year-round mean density maps. The results revealed high regional differences in small delphinoid densities, confirmed the importance of the continental slope to large delphinoids and of canyons and seamounts to beaked and sperm whales, and quantified seasonal shifts in the densities of migratory baleen whales. The density maps, freely available online, are the first for these regions to be published in the peer-reviewed literature.

  3. Habitat-based cetacean density models for the U.S. Atlantic and Gulf of Mexico.

    PubMed

    Roberts, Jason J; Best, Benjamin D; Mannocci, Laura; Fujioka, Ei; Halpin, Patrick N; Palka, Debra L; Garrison, Lance P; Mullin, Keith D; Cole, Timothy V N; Khan, Christin B; McLellan, William A; Pabst, D Ann; Lockhart, Gwen G

    2016-03-03

    Cetaceans are protected worldwide but vulnerable to incidental harm from an expanding array of human activities at sea. Managing potential hazards to these highly-mobile populations increasingly requires a detailed understanding of their seasonal distributions and habitats. Pursuant to the urgent need for this knowledge for the U.S. Atlantic and Gulf of Mexico, we integrated 23 years of aerial and shipboard cetacean surveys, linked them to environmental covariates obtained from remote sensing and ocean models, and built habitat-based density models for 26 species and 3 multi-species guilds using distance sampling methodology. In the Atlantic, for 11 well-known species, model predictions resembled seasonal movement patterns previously suggested in the literature. For these we produced monthly mean density maps. For lesser-known taxa, and in the Gulf of Mexico, where seasonal movements were less well described, we produced year-round mean density maps. The results revealed high regional differences in small delphinoid densities, confirmed the importance of the continental slope to large delphinoids and of canyons and seamounts to beaked and sperm whales, and quantified seasonal shifts in the densities of migratory baleen whales. The density maps, freely available online, are the first for these regions to be published in the peer-reviewed literature.

  4. Habitat Suitability Index Models: Pileated woodpecker

    USGS Publications Warehouse

    Schroeder, Richard L.

    1983-01-01

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

  5. Development of a stream habitat index for the Northern Lakes and Forest Ecoregions

    USGS Publications Warehouse

    Goldstein, Robert M.; Wang, Lizhu; Simon, Thomas P.; Stewart, Paul M.

    2002-01-01

    Physical habitat was quantified in 105 randomly selected streams across the Northern Lakes and Forests Ecoregion during 1998 and 1999 to develop a stream habitat index for the region. Physical habitat measures (106) were classified into four groups: substrate, instream cover, riparian zone–land use, and geomorphology–hydrology. Variable reduction procedures yielded seven variables: sinuosity, percent of substrate gravel or larger, percent substrate as detritus or muck, percent of bank with forested cover, amount of bank erosion, number of large logs per 100 m, and mean length of pools. Streams were separated by a gradient value of 3 m/km (low N = 70; high N = 35) and assigned to model and test data sets. For low-gradient streams in the model data set, the seven habitat variables explained 47% of the variation in index of biotic integrity (IBI) scores. To produce the habitat index, the coefficients in the regression were used to weight each of the seven variables. For low-gradient streams in the test data set, the habitat index explained 20% of the variation in IBI scores. A habitat index could not be developed for high-gradient sites, probably due to the low number of sites. Comparison of habitat to IBI scores provides resource managers with a method to evaluate the contribution of habitat quality to the IBI score.

  6. Habitat modification alters the structure of tropical host-parasitoid food webs.

    PubMed

    Tylianakis, Jason M; Tscharntke, Teja; Lewis, Owen T

    2007-01-11

    Global conversion of natural habitats to agriculture has led to marked changes in species diversity and composition. However, it is less clear how habitat modification affects interactions among species. Networks of feeding interactions (food webs) describe the underlying structure of ecological communities, and might be crucially linked to their stability and function. Here, we analyse 48 quantitative food webs for cavity-nesting bees, wasps and their parasitoids across five tropical habitat types. We found marked changes in food-web structure across the modification gradient, despite little variation in species richness. The evenness of interaction frequencies declined with habitat modification, with most energy flowing along one or a few pathways in intensively managed agricultural habitats. In modified habitats there was a higher ratio of parasitoid to host species and increased parasitism rates, with implications for the important ecosystem services, such as pollination and biological control, that are performed by host bees and wasps. The most abundant parasitoid species was more specialized in modified habitats, with reduced attack rates on alternative hosts. Conventional community descriptors failed to discriminate adequately among habitats, indicating that perturbation of the structure and function of ecological communities might be overlooked in studies that do not document and quantify species interactions. Altered interaction structure therefore represents an insidious and functionally important hidden effect of habitat modification by humans.

  7. Human Aspects and Habitat Studies from EuroGeoMars Campaign

    NASA Astrophysics Data System (ADS)

    Boche-Sauvan, L.; Pletser, V.; Foing, B. H.; Eurogeomars Team

    2009-04-01

    Introduction: In a human space mission, the human factor is one of the dominant aspects, which may strongly influence work results and efficiency. To quantify such a difficult and uncontrollable aspect of space missions, it is necessary to reproduce as exactly as possible the environmental and technical conditions in which astronauts may be confronted: limited re-sources, social interactions in an isolated and cramped area… We will take the benefit of the EuroGeoMars campaign in the Mars Desert Research Station (MDRS, Mars Society) in Utah to observe and measure these characteristics. EuroGeoMars campaign: The EuroGeoMars team aims at assessing the development of scientific protocols and techniques in geology and biology research in planetary conditions. In this framework, MRDS simulation constitutes its main achievement. The scientific investigations conducted in MRDS are expected to provide valuable results, beyond the simple reflection on how managing planetary specific conditions. Nevertheless, the different scientific protocols, even tailored for extreme environmental conditions, require an exhaustive analysis to evaluate how the results and their timing may possibly be affected. MDRS: The MDRS habitat will demand the crew members to work in a cramped environment, surrounded by dust and very limited manpower. Moreover, energy power and communication bandwidth will be limited to the crew members. Human aspects and habitat studies: The crewmember will work in an uncomfortable environment in the habitat: dust, cramping and crowd. Moreover, the sustainibility of the mission will relie on an optimal energy and ressources sharing. This will impose a planification of the different investigating activities. The study of the human aspects and habitat will be performed in terms of impact on scientific and technical tasks rather than in terms of crew's comfort. As any astronaut will previously be aware of the daily condition, we want to improve the working conditions

  8. Space habitat contamination model

    NASA Technical Reports Server (NTRS)

    Morgenthaler, George W.

    1990-01-01

    When one considers the missions that are involved in Space Exploration Initiative (SEI), a continuous Lunar Base at which astronauts will perform scientific experiments as well as being the center for Lunar resource exploitation, a human visit to the surface of Mars, and, later, the development of a Mars base, one recognizes that we have entered a new realm of space exploration activity. During the SEI era, human beings who are involved in such missions will be away from Earth for extended periods of time, even for years. For example, the classical Hohmann transfer round trip mission to Mars would involve a flight of 31 months, including the stay time in the vicinity of Mars. Of course, other Mars trips such as the Venus Fly-By mission (22 months) and the Mars Sprint mission (15 months) pose much less taxing problems, but still problems which put human space presence in a domain where human survival has not yet been tested and thoroughly understood. Humans have never before been placed into an isolated, low-gravity, hermetically sealed, contaminant-prone environment for periods well in excess of one year and then been expected to function normally upon return to Earth. This presentation develops a systems model to help analyze the space habitat containment growth problem and to indicate the thresholds of astronaut risk, astronaut operational impairment, and methods of risk mitigation. The model inputs were discussed with toxicology experts at the University of Colorado Health Services Center and the University of Rochester.

  9. Habitat selection responses of parents to offspring predation risk: An experimental test

    USGS Publications Warehouse

    Fontaine, J.J.; Martin, T.E.

    2006-01-01

    The ability of nest predation to influence habitat settlement decisions in birds is widely debated, despite its importance in limiting fitness. Here, we experimentally manipulated nest predation risk across a landscape and asked the question, do migratory birds assess and respond to variation in nest predation risk when choosing breeding habitats? We examined habitat preference by quantifying the density and settlement date of eight species of migratory passerines breeding in areas with and without intact nest predator communities. We found consistently more individuals nesting in areas with reduced nest predation than in areas with intact predator assemblages, although predation risk had no influence on settlement or breeding phenology. Additionally, those individuals occupying safer nesting habitats exhibited increased singing activity. These findings support a causal relationship between habitat choice and nest predation risk and suggest the importance of nest predation risk in shaping avian community structure and breeding activity. ?? 2006 by The University of Chicago. All rights reserved.

  10. Habitat quality from individual- and population-level perspectives and implications for management

    USGS Publications Warehouse

    Boves, Than J.; Rodewald, Amanda D.; Wood, Petra Bohall; Buehler, David A.; Larkin, Jeffrey L.; Wigley, T. Bently; Keyser, Patrick D.

    2015-01-01

    Many wildlife management prescriptions are either implicitly or explicitly designed to improve habitat quality for a focal species, but habitat quality is often difficult to quantify. Depending upon the approach used to define and identify high-quality habitat, management decisions may differ widely. Although individual-level measures of habitat quality based on per capita reproduction (e.g., average nesting success, number of young produced per pair) are most common in the literature, they may not align with population-level measures that reflect number of young produced within a defined area. Using data on the cerulean warbler (Setophaga cerulea) collected in the Cumberland Mountains (Tennessee, USA; 2008–2010) as an example, we illustrate how lack of concordance between individual- and population-level measures of habitat quality can have real-world management implications.

  11. Quantifying drivers of population dynamics for a migratory bird throughout the annual cycle.

    PubMed

    Rushing, Clark S; Ryder, Thomas B; Marra, Peter P

    2016-01-27

    Worldwide, migratory species are undergoing rapid declines but understanding the factors driving these declines is hindered by missing information about migratory connectivity and the lack of data to quantify environmental processes across the annual cycle. Here, we combined range-wide information about migratory connectivity with global remote-sensing data to quantify the relative importance of breeding and non-breeding environmental processes to persistent long-term population declines of a migratory songbird, the wood thrush (Hylocichla mustelina). Consistent with theoretical predictions about population limitation of migratory birds, our results suggest that habitat loss and climate have contributed to the observed declines in wood thrush breeding abundance, yet the relative importance of breeding versus non-breeding factors is population-specific. For example, high-abundance core breeding populations appear to be more limited by habitat loss, whereas low-abundance, peripheral populations appear to be limited by climate-driven seasonal interactions. Further, our analysis indicates that the relative impact of breeding habitat loss is at least three to six times greater than the impact of equivalent non-breeding habitat loss and therefore the steepest regional declines have likely been driven by the loss of breeding habitat. These results underscore the need for population-specific conservation strategies implemented throughout the annual cycle to reverse long-term declines.

  12. Quantifying drivers of population dynamics for a migratory bird throughout the annual cycle.

    PubMed

    Rushing, Clark S; Ryder, Thomas B; Marra, Peter P

    2016-01-27

    Worldwide, migratory species are undergoing rapid declines but understanding the factors driving these declines is hindered by missing information about migratory connectivity and the lack of data to quantify environmental processes across the annual cycle. Here, we combined range-wide information about migratory connectivity with global remote-sensing data to quantify the relative importance of breeding and non-breeding environmental processes to persistent long-term population declines of a migratory songbird, the wood thrush (Hylocichla mustelina). Consistent with theoretical predictions about population limitation of migratory birds, our results suggest that habitat loss and climate have contributed to the observed declines in wood thrush breeding abundance, yet the relative importance of breeding versus non-breeding factors is population-specific. For example, high-abundance core breeding populations appear to be more limited by habitat loss, whereas low-abundance, peripheral populations appear to be limited by climate-driven seasonal interactions. Further, our analysis indicates that the relative impact of breeding habitat loss is at least three to six times greater than the impact of equivalent non-breeding habitat loss and therefore the steepest regional declines have likely been driven by the loss of breeding habitat. These results underscore the need for population-specific conservation strategies implemented throughout the annual cycle to reverse long-term declines. PMID:26817774

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

    PubMed

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

    2016-01-01

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

  14. Quantifying torso deformity in scoliosis

    NASA Astrophysics Data System (ADS)

    Ajemba, Peter O.; Kumar, Anish; Durdle, Nelson G.; Raso, V. James

    2006-03-01

    Scoliosis affects the alignment of the spine and the shape of the torso. Most scoliosis patients and their families are more concerned about the effect of scoliosis on the torso than its effect on the spine. There is a need to develop robust techniques for quantifying torso deformity based on full torso scans. In this paper, deformation indices obtained from orthogonal maps of full torso scans are used to quantify torso deformity in scoliosis. 'Orthogonal maps' are obtained by applying orthogonal transforms to 3D surface maps. (An 'orthogonal transform' maps a cylindrical coordinate system to a Cartesian coordinate system.) The technique was tested on 361 deformed computer models of the human torso and on 22 scans of volunteers (8 normal and 14 scoliosis). Deformation indices from the orthogonal maps correctly classified up to 95% of the volunteers with a specificity of 1.00 and a sensitivity of 0.91. In addition to classifying scoliosis, the system gives a visual representation of the entire torso in one view and is viable for use in a clinical environment for managing scoliosis.

  15. Quantifying spatiotemporal changes in a sagebrush ecosystem in relation to energy development.

    SciTech Connect

    Walston, L. J.; Cantwell, B. L.; Krummel, J. R.; Environmental Science Division

    2009-12-01

    Energy development has been occurring in the intermountain western United States for over a century, yet few studies have attempted to spatially quantify the impacts of this disturbance on native ecosystems. We used temporal remotely sensed data for the Pinedale Anticline Project Area (PAPA) in western Wyoming, a region that has experienced increased natural gas development within the past 10 yr, to quantify the spatiotemporal distribution of Wyoming big sagebrush Artemisia tridentata, natural gas development, and other landcover types. Our analyses included 5 Landsat Thematic Mapper (TM) images of the PAPA over a 22-yr period (1985-2006). We determined whether Wyoming big sagebrush spatiotemporal patterns were associated with natural gas development or other landcover types. We also developed a footprint model to determine the direct and indirect impacts of natural gas development on the distribution of Wyoming big sagebrush habitats. Over the 22-yr period, we observed an inverse relationship between the amount of Wyoming big sagebrush habitat and natural gas development. During this time, Wyoming big sagebrush habitat declined linearly at a rate of 0.2% yr-1 (4.5% total net loss), whereas natural gas development increased exponentially at a rate of 20% yr-1 (4800% total net increase). Our evaluation indicated that, by 2006, natural gas development directly impacted 2.7% (1750 ha) of original Wyoming big sagebrush habitat. Indirect impacts, quantified to account for degraded habitat quality, affected as much as 58.5% (assuming 1000-m buffers) of the original Wyoming big sagebrush habitat. Integrating assessments of the direct and indirect impacts will yield a better elucidation of the overall effects of disturbances on ecosystem function and quality.

  16. Diversity and Community Composition of Vertebrates in Desert River Habitats.

    PubMed

    Free, C L; Baxter, G S; Dickman, C R; Lisle, A; Leung, L K-P

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  17. Diversity and Community Composition of Vertebrates in Desert River Habitats.

    PubMed

    Free, C L; Baxter, G S; Dickman, C R; Lisle, A; Leung, L K-P

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning.

  18. Diversity and Community Composition of Vertebrates in Desert River Habitats

    PubMed Central

    Free, C. L.; Baxter, G. S.; Dickman, C. R.; Lisle, A.; Leung, L. K.-P.

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  19. 76 FR 25307 - Incidental Take Permit and Habitat Conservation Plan for PacifiCorp Klamath Hydroelectric Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... National Oceanic and Atmospheric Administration RIN 0648-XA410 Incidental Take Permit and Habitat... of availability of draft environmental assessment, habitat conservation plan, implementing agreement...-year period. As required by the ESA, PacifiCorp has also prepared a Habitat Conservation Plan (Plan)...

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

    USGS Publications Warehouse

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

    2006-01-01

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

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

    PubMed

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

    2014-01-01

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

  2. Habitat and Forage Associations of a Naturally Colonising Insect Pollinator, the Tree Bumblebee Bombus hypnorum

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  4. Barcoding a quantified food web: crypsis, concepts, ecology and hypotheses.

    PubMed

    Smith, M Alex; Eveleigh, Eldon S; McCann, Kevin S; Merilo, Mark T; McCarthy, Peter C; Van Rooyen, Kathleen I

    2011-01-01

    The efficient and effective monitoring of individuals and populations is critically dependent on correct species identification. While this point may seem obvious, identifying the majority of the more than 100 natural enemies involved in the spruce budworm (Choristoneura fumiferana--SBW) food web remains a non-trivial endeavor. Insect parasitoids play a major role in the processes governing the population dynamics of SBW throughout eastern North America. However, these species are at the leading edge of the taxonomic impediment and integrating standardized identification capacity into existing field programs would provide clear benefits. We asked to what extent DNA barcoding the SBW food web would alter our understanding of the diversity and connectence of the food web and the frequency of generalists vs. specialists in different forest habitats. We DNA barcoded over 10% of the insects collected from the SBW food web in three New Brunswick forest plots from 1983 to 1993. For 30% of these specimens, we amplified at least one additional nuclear region. When the nodes of the food web were estimated based on barcode divergences (using molecular operational taxonomic units (MOTU) or phylogenetic diversity (PD)--the food web became much more diverse and connectence was reduced. We tested one measure of food web structure (the "bird feeder effect") and found no difference compared to the morphologically based predictions. Many, but not all, of the presumably polyphagous parasitoids now appear to be morphologically-cryptic host-specialists. To our knowledge, this project is the first to barcode a food web in which interactions have already been well-documented and described in space, time and abundance. It is poised to be a system in which field-based methods permit the identification capacity required by forestry scientists. Food web barcoding provided an effective tool for the accurate identification of all species involved in the cascading effects of future budworm

  5. The Habitat Demonstration Unit Project Overview

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.; Grill, Tracy R.; Tri, Terry O.; Howe, Alan S.

    2010-01-01

    This paper will describe an overview of the National Aeronautics and Space Administration (NASA) led multi-center Habitat Demonstration Unit (HDU) Project. The HDU project is a "technology-pull" project that integrates technologies and innovations from numerous NASA centers. This project will be used to investigate and validate surface architectures, operations concepts, and requirements definition of various habitation concepts. The first habitation configuration this project will build and test is the Pressurized Excursion Module (PEM). This habitat configuration - the PEM - is based on the Constellation Architecture Scenario 12.1 concept of a vertically oriented habitat module. The HDU project will be tested as part of the 2010 Desert Research and Technologies Simulations (D-RATS) test objectives. The purpose of this project is to develop, integrate, test, and evaluate a habitat configuration in the context of the mission architectures and surface operation concepts. A multi-center approach will be leveraged to build, integrate, and test the PEM through a shared collaborative effort of multiple NASA centers. The HDU project is part of the strategic plan from the Exploration Systems Mission Directorate (ESMD) Directorate Integration Office (DIO) and the Lunar Surface Systems Project Office (LSSPO) to test surface elements in a surface analog environment. The 2010 analog field test will include two Lunar Electric Rovers (LER) and the PEM among other surface demonstration elements. This paper will describe the overall objectives, its various habitat configurations, strategic plan, and technology integration as it pertains to the 2010 and 2011 field analog tests. To accomplish the development of the PEM from conception in June 2009 to rollout for operations in July 2010, the HDU project team is using a set of design standards to define the interfaces between the various systems of PEM and to the payloads, such as the Geology Lab, that those systems will support

  6. Habitat selection of Rocky Mountain elk in a nonforested environment

    USGS Publications Warehouse

    Sawyer, H.; Nielson, R.M.; Lindzey, F.G.; Keith, L.; Powell, J.H.; Abraham, A.A.

    2007-01-01

    Recent expansions by Rocky Mountain elk (Cervus elaphus) into nonforested habitats across the Intermountain West have required managers to reconsider the traditional paradigms of forage and cover as they relate to managing elk and their habitats. We examined seasonal habitat selection patterns of a hunted elk population in a nonforested high-desert region of southwestern Wyoming, USA. We used 35,246 global positioning system locations collected from 33 adult female elk to model probability of use as a function of 6 habitat variables: slope, aspect, elevation, habitat diversity, distance to shrub cover, and distance to road. We developed resource selection probability functions for individual elk, and then we averaged the coefficients to estimate population-level models for summer and winter periods. We used the population-level models to generate predictive maps by assigning pixels across the study area to 1 of 4 use categories (i.e., high, medium-high, medium-low, or low), based on quartiles of the predictions. Model coefficients and predictive maps indicated that elk selected for summer habitats characterized by higher elevations in areas of high vegetative diversity, close to shrub cover, northerly aspects, moderate slopes, and away from roads. Winter habitat selection patterns were similar, except elk shifted to areas with lower elevations and southerly aspects. We validated predictive maps by using 528 locations collected from an independent sample of radiomarked elk (n = 55) and calculating the proportion of locations that occurred in each of the 4 use categories. Together, the high- and medium-high use categories of the summer and winter predictive maps contained 92% and 74% of summer and winter elk locations, respectively. Our population-level models and associated predictive maps were successful in predicting winter and summer habitat use by elk in a nonforested environment. In the absence of forest cover, elk seemed to rely on a combination of shrubs

  7. Habitat Evaluation Procedures (HEP) Report; North Eaton Lake, Technical Report 2005.

    SciTech Connect

    Entz, Ray

    2005-11-01

    On July 6, 2005, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the North Eaton Lake property, an acquisition completed by the Kalispel Tribe of Indians in November 2004. Evaluation species and appropriate models include bald eagle, black-capped chickadee, Canada goose, mallard, muskrat, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The North Eaton Lake Project provides a total of 235.05 Habitat Units (HUs) for the species evaluated. Open water habitat provides 9.38 HUs for Canada goose, mallard and muskrat. Emergent wetland habitat provides 11.36 HUs for Canada goose, mallard and muskrat. Forested wetland provides 10.97 HUs for bald eagle, black-capped chickadee, mallard and white-tailed deer. Conifer forest habitat provides 203.34 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. The objective of using HEP at the North Eaton Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  8. Habitat Evaluation Procedures (HEP) Report; Priest River Project, Technical Report 2005.

    SciTech Connect

    Entz, Ray

    2005-05-01

    On July 6, 2004, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the Priest River property, an acquisition completed by the Kalispel Tribe of Indians in 2001. Evaluation species and appropriate models include bald eagle, black-capped chickadee, Canada goose, mallard, yellow warbler, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The Priest River Project provides a total of 140.73 Habitat Units (HUs) for the species evaluated. Conifer forest habitat provides 60.05 HUs for bald eagle, black-capped chickadee, and white-tailed deer. Grassland meadow habitat provides 7.39 HUs for Canada goose and mallard. Scrub-shrub vegetation provides 71.13 HUs for mallard, yellow warbler, and white-tailed deer. Open water habitat provides 2.16 HUs for Canada goose and mallard. The objective of using HEP at the Priest River Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  9. Coastal habitats as surrogates for taxonomic, functional and trophic structures of benthic faunal communities.

    PubMed

    Törnroos, Anna; Nordström, Marie C; Bonsdorff, Erik

    2013-01-01

    Due to human impact, there is extensive degradation and loss of marine habitats, which calls for measures that incorporate taxonomic as well as functional and trophic aspects of biodiversity. Since such data is less easily quantifiable in nature, the use of habitats as surrogates or proxies for biodiversity is on the rise in marine conservation and management. However, there is a critical gap in knowledge of whether pre-defined habitat units adequately represent the functional and trophic structure of communities. We also lack comparisons of different measures of community structure in terms of both between- (β) and within-habitat (α) variability when accounting for species densities. Thus, we evaluated a priori defined coastal habitats as surrogates for traditional taxonomic, functional and trophic zoobenthic community structure. We focused on four habitats (bare sand, canopy-forming algae, seagrass above- and belowground), all easily delineated in nature and defined through classification systems. We analyzed uni- and multivariate data on species and trait diversity as well as stable isotope ratios of benthic macrofauna. A good fit between habitat types and taxonomic and functional structure was found, although habitats were more similar functionally. This was attributed to within-habitat heterogeneity so when habitat divisions matched the taxonomic structure, only bare sand was functionally distinct. The pre-defined habitats did not meet the variability of trophic structure, which also proved to differentiate on a smaller spatial scale. The quantification of trophic structure using species density only identified an epi- and an infaunal unit. To summarize the results we present a conceptual model illustrating the match between pre-defined habitat types and the taxonomic, functional and trophic community structure. Our results show the importance of including functional and trophic aspects more comprehensively in marine management and spatial planning.

  10. QUANTIFYING ULTRAVIOLET RADIATION DOSE RELATIVE TO WETLAND HABITAT VARIABLES FOR THE ASSESSMENT OF RISK TO AMPHIBIANS

    EPA Science Inventory

    Ultraviolet B radiation (UV-B) has increased globally over the last several decades due to reduction of stratospheric ozone. UV-B may also increase when climate change alters cloud cover, rainfall, and distributions of vegetation. In aquatic systems, these factors can also intera...

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

    USGS Publications Warehouse

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

    2007-01-01

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

  12. The ecology of urban habitats

    SciTech Connect

    Gilbert, O.L.

    1989-01-01

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

  13. Biodiversity in urban habitat patches.

    PubMed

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

    2006-05-01

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

  14. Columbia River Wildlife Mitigation Habitat Evaluation Procedures Report / Scotch Creek Wildlife Area, Berg Brothers, and Douglas County Pygmy Rabbit Projects.

    SciTech Connect

    Ashley, Paul R.

    1997-01-01

    This Habitat Evaluation Procedure study was conducted to determine baseline habitat units (HUs) on the Scotch Creek, Mineral Hill, Pogue Mountain, Chesaw and Tunk Valley Habitat Areas (collectively known as the Scotch Creek Wildlife Area) in Okanogan County, Sagebrush Flat and the Dormaler property in Douglas County, and the Berg Brothers ranch located in Okanogan County within the Colville Reservation. A HEP team comprised of individuals from the Washington Department of Fish and Wildlife, the Confederated Tribes of the Colville Reservation, and the Natural Resources Conservation Service (Appendix A) conducted baseline habitat surveys using the following HEP evaluation species: mule deer (Odocoileus hemionus), sharp-tailed grouse (Tympanuchus phasianellus), pygmy rabbit (Brachylagus idahoensis), white-tailed deer (Odocoileus virginiana), mink (Mustela vison), Canada goose (Branta canadensis), downy woodpecker (Picoides pubescens), Lewis woodpecker (Melanerpes lewis), and Yellow warbler (Dendroica petechia). Results of the HEP analysis are listed below. General ratings (poor, marginal, fair, etc.,) are described in Appendix B. Mule deer habitat was marginal lacking diversity and quantify of suitable browse species. Sharp-tailed grouse habitat was marginal lacking residual nesting cover and suitable winter habitat Pygmy rabbit habitat was in fair condition except for the Dormaier property which was rated marginal due to excessive shrub canopy closure at some sites. This report is an analysis of baseline habitat conditions on mitigation project lands and provides estimated habitat units for mitigation crediting purposes. In addition, information from this document could be used by wildlife habitat managers to develop management strategies for specific project sites.

  15. Quantifying Aggressive Behavior in Zebrafish.

    PubMed

    Teles, Magda C; Oliveira, Rui F

    2016-01-01

    Aggression is a complex behavior that influences social relationships and can be seen as adaptive or maladaptive depending on the context and intensity of expression. A model organism suitable for genetic dissection of the underlying neural mechanisms of aggressive behavior is still needed. Zebrafish has already proven to be a powerful vertebrate model organism for the study of normal and pathological brain function. Despite the fact that zebrafish is a gregarious species that forms shoals, when allowed to interact in pairs, both males and females express aggressive behavior and establish dominance hierarchies. Here, we describe two protocols that can be used to quantify aggressive behavior in zebrafish, using two different paradigms: (1) staged fights between real opponents and (2) mirror-elicited fights. We also discuss the methodology for the behavior analysis, the expected results for both paradigms, and the advantages and disadvantages of each paradigm in face of the specific goals of the study. PMID:27464816

  16. Integration Process for the Habitat Demonstration Unit

    NASA Technical Reports Server (NTRS)

    Gill, Tracy; Merbitz, Jerad; Kennedy, Kriss; Tri, Terry; Howe, A. Scott

    2010-01-01

    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 centers and outside collaborators and poses a challenge in integrating these disparate efforts into a cohesive architecture To complete the development of the HDU from conception in June 2009 to rollout for operations in July 2010, a cohesive integration strategy has been developed to integrate the various systems of HDU and the payloads, such as the Geology Lab, that those systems will support The utilization of interface design standards and uniquely tailored reviews have allowed for an accelerated design process Scheduled activities include early fit-checks and the utilization of a Habitat avionics test bed prior to equipment installation into HDU A coordinated effort to utilize modeling and simulation systems has aided in design and integration concept development Modeling tools have been effective in hardware systems layout, cable routing and length estimation, and human factors analysis Decision processes on the shell development including the assembly sequence and the transportation have been fleshed out early on HDU to maximize the efficiency of both integration and field operations Incremental test operations leading up to an integrated systems test allows for an orderly systems test program The HDU will begin its journey as an emulation of a Pressurized Excursion Module (PEM) for 2010 field testing and then may evolve to a Pressurized Core Module (PCM) for 2011 and later field tests, depending on agency architecture decisions The HDU deployment will vary slightly from current lunar architecture plans to include developmental hardware and software items and additional systems called opportunities for technology demonstration One of the HDU challenges has been designing to be prepared for the integration of

  17. Geopressured habitat: A literature review

    SciTech Connect

    Negus-de Wys, Jane

    1992-09-01

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

  18. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach

    PubMed Central

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  19. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach.

    PubMed

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  20. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach.

    PubMed

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  1. Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary, Annual Report of Research.

    SciTech Connect

    Bottom, Daniel L.; Simenstad, Charles A.; Campbell, Lance

    2009-05-15

    In 2002 with support from the U.S. Army Corps of Engineers (USACE), an interagency research team began investigating salmon life histories and habitat use in the lower Columbia River estuary to fill significant data gaps about the estuary's potential role in salmon decline and recovery . The Bonneville Power Administration (BPA) provided additional funding in 2004 to reconstruct historical changes in estuarine habitat opportunities and food web linkages of Columbia River salmon (Onchorhynchus spp.). Together these studies constitute the estuary's first comprehensive investigation of shallow-water habitats, including selected emergent, forested, and scrub-shrub wetlands. Among other findings, this research documented the importance of wetlands as nursery areas for juvenile salmon; quantified historical changes in the amounts and distributions of diverse habitat types in the lower estuary; documented estuarine residence times, ranging from weeks to months for many juvenile Chinook salmon (O. tshawytscha); and provided new evidence that contemporary salmonid food webs are supported disproportionately by wetland-derived prey resources. The results of these lower-estuary investigations also raised many new questions about habitat functions, historical habitat distributions, and salmon life histories in other areas of the Columbia River estuary that have not been adequately investigated. For example, quantitative estimates of historical habitat changes are available only for the lower 75 km of the estuary, although tidal influence extends 217 km upriver to Bonneville Dam. Because the otolith techniques used to reconstruct salmon life histories rely on detection of a chemical signature (strontium) for salt water, the estuarine residency information we have collected to date applies only to the lower 30 or 35 km of the estuary, where fish first encounter ocean water. We lack information about salmon habitat use, life histories, and growth within the long tidal

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

    SciTech Connect

    Bumgarner, Joseph D.

    1999-03-01

    The Asotin Creek Model Watershed Master Plan was completed 1994. The plan was developed by a landowner steering committee for the Asotin County Conservation District (ACCD), with technical support from the various Federal, State and local entities. Actions identified within the plan to improve the Asotin Creek ecosystem fall into four main categories, (1) Stream and Riparian, (2) Forestland, (3) Rangeland, and (4) Cropland. Specific actions to be carried out within the stream and in the riparian area to improve fish habitat were, (a) create more pools, (b) increase the amount of large organic debris (LOD), (c) increase the riparian buffer zone through tree planting, and (d) increase fencing to limit livestock access; additionally, the actions are intended to stabilize the river channel, reduce sediment input, and protect private property. Fish species of main concern in Asotin Creek are summer steelhead (Oncorhynchus mykiss), spring chinook (Oncorhynchus tshawytscha), and bull trout (Salvelinus confluentus). Spring chinook in Asotin Creek are considered extinct (Bumgarner et al. 1998); bull trout and summer steelhead are below historical levels and are currently as ''threatened'' under the ESA. In 1998, 16 instream habitat projects were planned by ACCD along with local landowners. The ACCD identified the need for a more detailed analysis of these instream projects to fully evaluate their effectiveness at improving fish habitat. The Washington Department of Fish and Wildlife's (WDFW) Snake River Lab (SRL) was contracted by the ACCD to take pre-construction measurements of the existing habitat (pools, LOD, width, depth, etc.) within each identified site, and to eventually evaluate fish use within these sites. All pre-construction habitat measurements were completed between 6 and 14 July, 1998. 1998 was the first year that this sort of evaluation has occurred. Post construction measurements of habitat structures installed in 1998, and fish usage evaluation, will be

  3. Seasonal habitat preference by the flagship species Testudo hermanni: Implications for the conservation of coastal dunes.

    PubMed

    Berardo, Fabiana; Carranza, Maria Laura; Frate, Ludovico; Stanisci, Angela; Loy, Anna

    2015-05-01

    In this study, we explored if, how, and when the European Union habitats (EU sensu Habitats Directive 92/43/CEE) are used by the flagship species Testudo hermanni in a well-preserved coastal dune system of the Italian peninsula. Radio telemetry data and fine-scale vegetation habitat mapping were used to address the following questions: (a) is each EU habitat used differentially by Hermann's tortoises? (b) is there any seasonal variation in this utilization pattern? (c) how does each habitat contribute to the ecological requirements of the tortoises? Nine tortoises were fitted with transmitters and monitored for the entire season of activity. The eight EU habitats present in the study area were surveyed and mapped using GIS. The seasonal preferential use or avoidance of each habitat was tested by comparing, through bootstrap tests, the proportion of habitat occupied (piTh) with the proportion of available habitat in the entire landscape (piL). The analysis of 340 spatial locations showed a marked preference for the Cisto-Lavanduletalia dune sclerophyllous scrubs (EU code 2260) and a seasonal selection of Juniperus macrocarpa bushes (EU code 2250(*)), wooded dunes with Pinus (EU code 2270) and mosaic of dune grasslands and sclerophyllous scrubs (EU codes 2230, 2240, 2260). Seasonal variation of habitat preference was interpreted in light of the different feeding, thermoregulation and reproductive needs of the tortoises. Our results stress the ecological value of EU coastal dune habitats and suggest prioritization of conservation efforts in these ecosystems.

  4. Seasonal habitat preference by the flagship species Testudo hermanni: Implications for the conservation of coastal dunes.

    PubMed

    Berardo, Fabiana; Carranza, Maria Laura; Frate, Ludovico; Stanisci, Angela; Loy, Anna

    2015-05-01

    In this study, we explored if, how, and when the European Union habitats (EU sensu Habitats Directive 92/43/CEE) are used by the flagship species Testudo hermanni in a well-preserved coastal dune system of the Italian peninsula. Radio telemetry data and fine-scale vegetation habitat mapping were used to address the following questions: (a) is each EU habitat used differentially by Hermann's tortoises? (b) is there any seasonal variation in this utilization pattern? (c) how does each habitat contribute to the ecological requirements of the tortoises? Nine tortoises were fitted with transmitters and monitored for the entire season of activity. The eight EU habitats present in the study area were surveyed and mapped using GIS. The seasonal preferential use or avoidance of each habitat was tested by comparing, through bootstrap tests, the proportion of habitat occupied (piTh) with the proportion of available habitat in the entire landscape (piL). The analysis of 340 spatial locations showed a marked preference for the Cisto-Lavanduletalia dune sclerophyllous scrubs (EU code 2260) and a seasonal selection of Juniperus macrocarpa bushes (EU code 2250(*)), wooded dunes with Pinus (EU code 2270) and mosaic of dune grasslands and sclerophyllous scrubs (EU codes 2230, 2240, 2260). Seasonal variation of habitat preference was interpreted in light of the different feeding, thermoregulation and reproductive needs of the tortoises. Our results stress the ecological value of EU coastal dune habitats and suggest prioritization of conservation efforts in these ecosystems. PMID:25843221

  5. How mechanisms of habitat preference evolve and promote divergence with gene flow.

    PubMed

    Berner, D; Thibert-Plante, X

    2015-09-01

    Habitat preference may promote adaptive divergence and speciation, yet the conditions under which this is likely are insufficiently explored. We use individual-based simulations to study the evolution and consequence of habitat preference during divergence with gene flow, considering four different underlying genetically based behavioural mechanisms: natal habitat imprinting, phenotype-dependent, competition-dependent and direct genetic habitat preference. We find that the evolution of habitat preference generally requires initially high dispersal, is facilitated by asymmetry in population sizes between habitats, and is hindered by an increasing number of underlying genetic loci. Moreover, the probability of habitat preference to emerge and promote divergence differs greatly among the underlying mechanisms. Natal habitat imprinting evolves most easily and can allow full divergence in parameter ranges where no divergence is possible in the absence of habitat preference. The reason is that imprinting represents a one-allele mechanism of assortative mating linking dispersal behaviour very effectively to local selection. At the other extreme, direct genetic habitat preference, a two-allele mechanism, evolves under restricted conditions only, and even then facilitates divergence weakly. Overall, our results indicate that habitat preference can be a strong reproductive barrier promoting divergence with gene flow, but that this is highly contingent on the underlying preference mechanism.

  6. How mechanisms of habitat preference evolve and promote divergence with gene flow

    PubMed Central

    Berner, Daniel

    2015-01-01

    Habitat preference may promote adaptive divergence and speciation, yet the conditions under which this is likely are insufficiently explored. We use individual-based simulations to study the evolution and consequence of habitat preference during divergence with gene flow, considering four different underlying genetically-based behavioral mechanisms: natal habitat imprinting, phenotype-dependent, competition-dependent, and direct genetic habitat preference. We find that the evolution of habitat preference generally requires initially high dispersal, is facilitated by asymmetry in population sizes between habitats, and is hindered by an increasing number of underlying genetic loci. Moreover, the probability of habitat preference to emerge and promote divergence differs greatly among the underlying mechanisms. Natal habitat imprinting evolves most easily and can allow full divergence in parameter ranges where no divergence is possible in the absence of habitat preference. The reason is that imprinting represents a one-allele mechanism of assortative mating linking dispersal behavior very effectively to local selection. At the other extreme, direct genetic habitat preference, a two-allele mechanism, evolves under restricted conditions only, and even then facilitates divergence weakly. Overall, our results indicate that habitat preference can be a strong reproductive barrier promoting divergence with gene flow, but that this is highly contingent on the underlying preference mechanism. PMID:26119841

  7. Potential effects of direct transfer payments on farmland habitat diversity in a marginal European landscape.

    PubMed

    Reger, Birgit; Sheridan, Patrick; Simmering, Dietmar; Otte, Annette; Waldhardt, Rainer

    2009-06-01

    Farmland habitat diversity in marginal European landscapes changed significantly in the past decades. Further changes toward homogenization are expected, particularly in the course of European agricultural policy. Based on three alternative transfer payment schemes, we modeled spatially explicit potential effects on the farmland habitat diversity in a marginal European landscape. We defined (1) a scenario with direct transfer payments coupled to production, (2) a scenario with direct transfer payments decoupled from production, and (3) a scenario phasing out all direct transfer payments. We characterized habitat diversity with three indices: habitat richness, evenness, and rarity. The habitat pattern in 1995 served as reference for comparison. All scenarios predicted a general trend of homogenization of the farmland habitat pattern, yet to a differing extent. Transfer payments coupled to production (Scenario 1) favored the abandonment of agricultural production, particularly in low-productive areas and arable land use in more productive areas. Habitat richness and habitat evenness had intermediate values in this scenario. Decoupling transfer payments from production (Scenario 2) supported grassland as most profitable farming system. This led to a grassland-dominated landscape with low values of all habitat diversity indices. Phasing out transfer payments (Scenario 3) resulted in complete abandonment or afforestation of agricultural land and extremely low values in all habitat diversity indices. Scenario results indicate that transfer payments may prevent cessation of agricultural production, but may not counteract homogenization in marginal landscapes. Conserving high farmland habitat diversity in such landscapes may require support schemes, e.g., Pillar Two of EU Common Agricultural Policy.

  8. Animal biometrics: quantifying and detecting phenotypic appearance.

    PubMed

    Kühl, Hjalmar S; Burghardt, Tilo

    2013-07-01

    Animal biometrics is an emerging field that develops quantified approaches for representing and detecting the phenotypic appearance of species, individuals, behaviors, and morphological traits. It operates at the intersection between pattern recognition, ecology, and information sciences, producing computerized systems for phenotypic measurement and interpretation. Animal biometrics can benefit a wide range of disciplines, including biogeography, population ecology, and behavioral research. Currently, real-world applications are gaining momentum, augmenting the quantity and quality of ecological data collection and processing. However, to advance animal biometrics will require integration of methodologies among the scientific disciplines involved. Such efforts will be worthwhile because the great potential of this approach rests with the formal abstraction of phenomics, to create tractable interfaces between different organizational levels of life.

  9. Quantifying Evaporation in a Permeable Pavement System

    EPA Science Inventory

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  10. Quantifying foot deformation using finite helical angle.

    PubMed

    Pothrat, Claude; Goislard de Monsabert, Benjamin; Vigouroux, Laurent; Viehweger, Elke; Berton, Eric; Rao, Guillaume

    2015-10-15

    Foot intrinsic motion originates from the combination of numerous joint motions giving this segment a high adaptive ability. Existing foot kinematic models are mostly focused on analyzing small scale foot bone to bone motions which require both complex experimental methodology and complex interpretative work to assess the global foot functionality. This study proposes a method to assess the total foot deformation by calculating a helical angle from the relative motions of the rearfoot and the forefoot. This method required a limited number of retro-reflective markers placed on the foot and was tested for five different movements (walking, forefoot impact running, heel impact running, 90° cutting, and 180° U-turn) and 12 participants. Overtime intraclass correlation coefficients were calculated to quantify the helical angle pattern repeatability for each movement. Our results indicated that the method was suitable to identify the different motions as different amplitudes of helical angle were observed according to the flexibility required in each movement. Moreover, the results showed that the repeatability could be used to identify the mastering of each motion as this repeatability was high for well mastered movements. Together with existing methods, this new protocol could be applied to fully assess foot function in sport or clinical contexts.

  11. Choosing appropriate techniques for quantifying groundwater recharge

    USGS Publications Warehouse

    Scanlon, B.R.; Healy, R.W.; Cook, P.G.

    2002-01-01

    Various techniques are available to quantify recharge; however, choosing appropriate techniques is often difficult. Important considerations in choosing a technique include space/time scales, range, and reliability of recharge estimates based on different techniques; other factors may limit the application of particular techniques. The goal of the recharge study is important because it may dictate the required space/time scales of the recharge estimates. Typical study goals include water-resource evaluation, which requires information on recharge over large spatial scales and on decadal time scales; and evaluation of aquifer vulnerability to contamination, which requires detailed information on spatial variability and preferential flow. The range of recharge rates that can be estimated using different approaches should be matched to expected recharge rates at a site. The reliability of recharge estimates using different techniques is variable. Techniques based on surface-water and unsaturated-zone data provide estimates of potential recharge, whereas those based on groundwater data generally provide estimates of actual recharge. Uncertainties in each approach to estimating recharge underscore the need for application of multiple techniques to increase reliability of recharge estimates.

  12. Habitat Suitability Index Models: Bigmouth buffalo

    USGS Publications Warehouse

    Edwards, Elizabeth A.

    1983-01-01

    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.

  13. Habitat Suitability Index Models: Eastern brown pelican

    USGS Publications Warehouse

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

    1985-01-01

    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.

  14. Habitat degradation may affect niche segregation patterns in lizards

    NASA Astrophysics Data System (ADS)

    Pelegrin, N.; Chani, J. M.; Echevarria, A. L.; Bucher, E. H.

    2013-08-01

    Lizards partition resources in three main niche dimensions: time, space and food. Activity time and microhabitat use are strongly influenced by thermal environment, and may differ between species according to thermal requirements and tolerance. As thermal characteristics are influenced by habitat structure, microhabitat use and activity of lizards can change in disturbed habitats. We compared activity and microhabitat use of two abundant lizard species of the Semi-arid Chaco of Argentina between a restored and a highly degraded Chaco forest, to determine how habitat degradation affects lizard segregation in time and space, hypothesizing that as activity and microhabitat use of lizards are related to habitat structure, activity and microhabitat use of individual species can be altered in degraded habitats, thus changing segregation patterns between them. Activity changed from an overlapped pattern in a restored forest to a segregated pattern in a degraded forest. A similar trend was observed for microhabitat use, although to a less extent. No correlation was found between air temperature and lizard activity, but lizard activity varied along the day and among sites. Contrary to what was believed, activity patterns of neotropical diurnal lizards are not fixed, but affected by multiple factors related to habitat structure and possibly to interspecific interactions. Changes in activity patterns and microhabitat use in degraded forests may have important implications when analyzing the effects of climate change on lizard species, due to synergistic effects.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  16. Functional variability of habitats within the Sacramento-San Joaquin Delta: Restoration implications

    USGS Publications Warehouse

    Lucas, L.V.; Cloern, J.E.; Thompson, J.K.; Monsen, N.E.

    2002-01-01

    We have now entered an era of large-scale attempts to restore ecological functions and biological communities in impaired ecosystems. Our knowledge base of complex ecosystems and interrelated functions is limited, so the outcomes of specific restoration actions are highly uncertain. One approach for exploring that uncertainty and anticipating the range of possible restoration outcomes is comparative study of existing habitats similar to future habitats slated for construction. Here we compare two examples of one habitat type targeted for restoration in the Sacramento-San Joaquin River Delta. We compare one critical ecological function provided by these shallow tidal habitats - production and distribution of phytoplankton biomass as the food supply to pelagic consumers. We measured spatial and short-term temporal variability of phytoplankton biomass and growth rate and quantified the hydrodynamic and biological processes governing that variability. Results show that the production and distribution of phytoplankton biomass can be highly variable within and between nearby habitats of the same type, due to variations in phytoplankton sources, sinks, and transport. Therefore, superficially similar, geographically proximate habitats can function very differently, and that functional variability introduces large uncertainties into the restoration process. Comparative study of existing habitats is one way ecosystem science can elucidate and potentially minimize restoration uncertainties, by identifying processes shaping habitat functionality, including those that can be controlled in the restoration design.

  17. Relationship between shrubs and foods in mountain plover habitat in Park County, Colorado

    USGS Publications Warehouse

    Schneider, S.C.; Wunder, Michael B.; Knopf, F.L.

    2006-01-01

    We explored habitat use in terms of vegetation structure and potential forage availability for mountain plovers (Charadrius montanus) in Park County, Colorado. We quantified the percentage cover of bare ground, percentage cover of shrubs (Chrysothamnus visadiflorus), linear distance to nearest shrub, arthropod biomass, and grasshopper density for 102 plots of 1,963 m2, 51 of which were occupied by plovers and 51 of which were selected randomly within previously-classified potential habitat. We modeled the probability of habitat use by plovers based on these measurements. We further subdivided the occupied plots to model probability of habitat use by adults with broods as compared with use by pre-nesting and post-nesting adults. Percentage of bare ground and probability of habitat use for adults with broods were related inversely, but not so for adults without broods. Grasshopper density was positively related to probability of habitat use by adults without broods, whereas proximity to nearest shrub was negatively related. We propose that habitat use by plovers in South Park is influenced by the amount of available shrub-grassland edge habitat and the availability of forage.

  18. Habitat Suitability Index Models: Flathead Catfish

    USGS Publications Warehouse

    Lee, Lawrence A.; Terrell, James W.

    1987-01-01

    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.

  19. Habitat Suitability Index Models: Cactus Wren

    USGS Publications Warehouse

    Short, Henry L.

    1985-01-01

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

  20. Habitat Suitability Index Models: Eastern Wild Turkey

    USGS Publications Warehouse

    Schroeder, Richard L.

    1985-01-01

    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.

  1. Habitat Suitability Index Models: Snapping turtle

    USGS Publications Warehouse

    Graves, Brent M.; Anderson, Stanley H.

    1987-01-01

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

  2. Habitat Suitability Index Models: Marsh wren

    USGS Publications Warehouse

    Gutzwiller, Kevin J.; Anderson, Stanley H.

    1987-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the marsh wren (Cistothorus palustris). 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.

  3. Habitat Suitability Index Models: Spotted owl

    USGS Publications Warehouse

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

    1985-01-01

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

  4. Habitat Suitability Index Models: Cactus wren

    USGS Publications Warehouse

    Short, Henry L.

    1985-01-01

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

  5. Habitat Suitability Index Models: Swamp rabbit

    USGS Publications Warehouse

    Allen, Arthur W.

    1985-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the swamp rabbit (Sylvilagus aquaticus). 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.

  6. Habitat Suitability Index Models: Eastern wild turkey

    USGS Publications Warehouse

    Schroeder, Richard L.

    1985-01-01

    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.

  7. Habitat Suitability Index Models: Hairy Woodpecker

    USGS Publications Warehouse

    Sousa, Patrick J.

    1987-01-01

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

  8. Habitat Suitability Index Models: Swamp Rabbit

    USGS Publications Warehouse

    Allen, Arthur W.

    1985-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the swamp rabbit (Sylvilagus aquaticus). 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.

  9. Habitat Suitability Index Models: Slider turtle

    USGS Publications Warehouse

    Morreale, Stephen J.; Gibbons, J. Whitfield

    1986-01-01

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

  10. Habitat Suitability Index Models: Barred Owl

    USGS Publications Warehouse

    Allen, Arthur W.

    1987-01-01

    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.

  11. Habitat Suitability Index Models: Spotted Owl

    USGS Publications Warehouse

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

    1985-01-01

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

  12. Bird communities of natural and modified habitats in Panama

    USGS Publications Warehouse

    Petit, L.J.; Petit, D.R.; Christian, D.G.; Powell, H.D.W.

    1999-01-01

    enhancement of agricultural and developed lands as wildlife habitat. To understand the true conservation value of these modified lands will require examination not only of numbers but also of the types of species supported by these habitats, their reproductive output and survival rates.

  13. Tracking changes and preventing loss in critical tiger habitat

    PubMed Central

    Joshi, Anup R.; Dinerstein, Eric; Wikramanayake, Eric; Anderson, Michael L.; Olson, David; Jones, Benjamin S.; Seidensticker, John; Lumpkin, Susan; Hansen, Matthew C.; Sizer, Nigel C.; Davis, Crystal L.; Palminteri, Suzanne; Hahn, Nathan R.

    2016-01-01

    The global population of wild tigers remains dangerously low at fewer than 3500 individuals. Habitat loss, along with poaching, can undermine the international target recovery of doubling the number of wild tigers by 2022. Using a new satellite-based monitoring system, we analyzed 14 years of forest loss data within the 76 landscapes (ranging from 278 to 269,983 km2) that have been prioritized for conservation of wild tigers. Our analysis provides an update of the status of tiger habitat and describes new applications of technology to detect precisely where forest loss is occurring in order to curb future habitat loss. Across the 76 landscapes, forest loss was far less than anticipated (79,597 ± 22,629 km2, 7.7% of remaining habitat) over the 14-year study period (2001–2014). Habitat loss was unevenly distributed within a subset of 29 landscapes deemed most critical for doubling wild tiger populations: 19 showed little change (1.5%), whereas 10 accounted for more than 98% (57,392 ± 16,316 km2) of habitat loss. Habitat loss in source population sites within 76 landscapes ranged from no loss to 435 ± 124 km2 (x¯=24km2, SD = 89, total = 1676 ± 476 km2). Doubling the tiger population by 2022 requires moving beyond tracking annual changes in habitat. We highlight near–real-time forest monitoring technologies that provide alerts of forest loss at relevant spatial and temporal scales to prevent further erosion. PMID:27051881

  14. Detecting, visualising, and quantifying mucins.

    PubMed

    Harrop, Ceri A; Thornton, David J; McGuckin, Michael A

    2012-01-01

    The extreme size, extensive glycosylation, and gel-forming nature of mucins make them a challenge to work with, and methodologies for the detection of mucins must take into consideration these features to ensure that one obtains both accurate and meaningful results. In understanding and appreciating the nature of mucins, this affords the researcher a valuable toolkit which can be used to full advantage in detecting, quantifying, and visualising mucins. The employment of a combinatorial approach to mucin detection, using antibody, chemical, and lectin detection methods, allows important information to be gleaned regarding the size, extent of glycosylation, specific mucin species, and distribution of mucins within a given sample. In this chapter, the researcher is guided through considerations into the structure of mucins and how this both affects the detection of mucins and can be used to full advantage. Techniques including ELISA, dot/slot blotting, and Western blotting, use of lectins and antibodies in mucin detection on membranes as well as immunohistochemistry and immunofluorescence on both tissues and cells grown on Transwell™ inserts are described. Notes along with each section advice the researcher on best practice and describe any associated limitations of a particular technique from which the researcher can further develop a particular protocol.

  15. Quantifying the vitamin D economy.

    PubMed

    Heaney, Robert P; Armas, Laura A G

    2015-01-01

    Vitamin D enters the body through multiple routes and in a variety of chemical forms. Utilization varies with input, demand, and genetics. Vitamin D and its metabolites are carried in the blood on a Gc protein that has three principal alleles with differing binding affinities and ethnic prevalences. Three major metabolites are produced, which act via two routes, endocrine and autocrine/paracrine, and in two compartments, extracellular and intracellular. Metabolic consumption is influenced by physiological controls, noxious stimuli, and tissue demand. When administered as a supplement, varying dosing schedules produce major differences in serum metabolite profiles. To understand vitamin D's role in human physiology, it is necessary both to identify the foregoing entities, mechanisms, and pathways and, specifically, to quantify them. This review was performed to delineate the principal entities and transitions involved in the vitamin D economy, summarize the status of present knowledge of the applicable rates and masses, draw inferences about functions that are implicit in these quantifications, and point out implications for the determination of adequacy. PMID:26024057

  16. Quantifying the vitamin D economy.

    PubMed

    Heaney, Robert P; Armas, Laura A G

    2015-01-01

    Vitamin D enters the body through multiple routes and in a variety of chemical forms. Utilization varies with input, demand, and genetics. Vitamin D and its metabolites are carried in the blood on a Gc protein that has three principal alleles with differing binding affinities and ethnic prevalences. Three major metabolites are produced, which act via two routes, endocrine and autocrine/paracrine, and in two compartments, extracellular and intracellular. Metabolic consumption is influenced by physiological controls, noxious stimuli, and tissue demand. When administered as a supplement, varying dosing schedules produce major differences in serum metabolite profiles. To understand vitamin D's role in human physiology, it is necessary both to identify the foregoing entities, mechanisms, and pathways and, specifically, to quantify them. This review was performed to delineate the principal entities and transitions involved in the vitamin D economy, summarize the status of present knowledge of the applicable rates and masses, draw inferences about functions that are implicit in these quantifications, and point out implications for the determination of adequacy.

  17. Quantifying Uncertainty in Epidemiological Models

    SciTech Connect

    Ramanathan, Arvind; Jha, Sumit Kumar

    2012-01-01

    Modern epidemiology has made use of a number of mathematical models, including ordinary differential equation (ODE) based models and agent based models (ABMs) to describe the dynamics of how a disease may spread within a population and enable the rational design of strategies for intervention that effectively contain the spread of the disease. Although such predictions are of fundamental importance in preventing the next global pandemic, there is a significant gap in trusting the outcomes/predictions solely based on such models. Hence, there is a need to develop approaches such that mathematical models can be calibrated against historical data. In addition, there is a need to develop rigorous uncertainty quantification approaches that can provide insights into when a model will fail and characterize the confidence in the (possibly multiple) model outcomes/predictions, when such retrospective analysis cannot be performed. In this paper, we outline an approach to develop uncertainty quantification approaches for epidemiological models using formal methods and model checking. By specifying the outcomes expected from a model in a suitable spatio-temporal logic, we use probabilistic model checking methods to quantify the probability with which the epidemiological model satisfies the specification. We argue that statistical model checking methods can solve the uncertainty quantification problem for complex epidemiological models.

  18. Quantifying periodicity in omics data.

    PubMed

    Amariei, Cornelia; Tomita, Masaru; Murray, Douglas B

    2014-01-01

    Oscillations play a significant role in biological systems, with many examples in the fast, ultradian, circadian, circalunar, and yearly time domains. However, determining periodicity in such data can be problematic. There are a number of computational methods to identify the periodic components in large datasets, such as signal-to-noise based Fourier decomposition, Fisher's g-test and autocorrelation. However, the available methods assume a sinusoidal model and do not attempt to quantify the waveform shape and the presence of multiple periodicities, which provide vital clues in determining the underlying dynamics. Here, we developed a Fourier based measure that generates a de-noised waveform from multiple significant frequencies. This waveform is then correlated with the raw data from the respiratory oscillation found in yeast, to provide oscillation statistics including waveform metrics and multi-periods. The method is compared and contrasted to commonly used statistics. Moreover, we show the utility of the program in the analysis of noisy datasets and other high-throughput analyses, such as metabolomics and flow cytometry, respectively.

  19. Landscape and fine scale habitat associations of the Loggerhead Shrike

    USGS Publications Warehouse

    Michaels, H.L.; Cully, J.E.

    1998-01-01

    This study was conducted to determine landscape and fine-scale vegetative variables associated with breeding Loggerhead Shrikes (Lanius ludovicianus) on Fort Riley Military Reservation, Kansas. Because Fort Riley is an Army training site, the influences of training disturbance to the vegetation, and range management practices on bird habitat patterns were also investigated. Breeding birds were surveyed in 1995 and 1996 using point counts. Survey plots were identified, a priori, at the landscape scale as either grassland, savannah, or woodland edge according to cover by woody vegetation. In 1996, fine-scale habitat at survey points and at bird use sites was measured and a principal components analysis used to characterize the fine-scale herbaceous vegetation structure. A military disturbance index was developed to quantify the severity of vehicle disturbance to the vegetation at survey and bird use sites. Shrikes were associated with savannah habitat at the landscape scale. Sites used by Loggerhead Shrikes were characterized at the fine-scale by tall, sparse, structurally heterogeneous herbaceous vegetation with high standing dead plant cover and low litter cover. At the fine-scale, tree and shrub density did not differ between sites used and not used by shrikes. Used sites did not differ from survey sites with respect to military training disturbance, hay harvest, or the number of years since a site was last burned. Our results in this study suggest that the shifting mosaic of vegetation on Fort Riley resulting from training and range management practices maintains adequate habitat for breeding shrikes.

  20. Ecological specialisation in habitat selection within a macropodid herbivore guild.

    PubMed

    Garnick, Sarah; Di Stefano, Julian; Elgar, Mark A; Coulson, Graeme

    2016-03-01

    Specialist species show stronger resource selection, narrower niches and lower niche overlap than generalist species. We examined ecological specialisation with respect to habitat selection in a macropodid community comprising the western grey kangaroo Macropus fuliginosus, red-necked wallaby M. rufogriseus and swamp wallaby Wallabia bicolor in the Grampians National Park, Victoria, Australia. We used radio tracking to quantify habitat selection. We predicted that because the fitness benefits of generalisation and specialisation differ, there would be a mix of generalised and specialised species in our community. As all three macropodid species show marked sexual dimorphism, we also expected that they would show sex-based specialisation. Finally, because many large herbivores select different habitats for foraging and resting, we predicted that our species would specialise on a subset of their overall selected habitat based on activity period (diurnal or nocturnal). All three species specialised on the available resources to some degree. Western grey kangaroos were specialists, at least during the active period. Niche data for the two wallaby species were harder to interpret so we could not determine their degree of specialisation. Within species, we found no evidence of sex-based specialisation. However, we found clear evidence of specialisation by activity period in western grey kangaroos and red-necked wallabies, but not in swamp wallabies. The strength of behavioural decisions made during the active period in influencing specialisation points to the likelihood that bottom-up processes regulate this community.

  1. Habitat specialization predicts genetic response to fragmentation in tropical birds.

    PubMed

    Khimoun, Aurélie; Eraud, Cyril; Ollivier, Anthony; Arnoux, Emilie; Rocheteau, Vincent; Bely, Marine; Lefol, Emilie; Delpuech, Martin; Carpentier, Marie-Laure; Leblond, Gilles; Levesque, Anthony; Charbonnel, Anaïs; Faivre, Bruno; Garnier, Stéphane

    2016-08-01

    Habitat fragmentation is one of the most severe threats to biodiversity as it may lead to changes in population genetic structure, with ultimate modifications of species evolutionary potential and local extinctions. Nonetheless, fragmentation does not equally affect all species and identifying which ecological traits are related to species sensitivity to habitat fragmentation could help prioritization of conservation efforts. Despite the theoretical link between species ecology and extinction proneness, comparative studies explicitly testing the hypothesis that particular ecological traits underlies species-specific population structure are rare. Here, we used a comparative approach on eight bird species, co-occurring across the same fragmented landscape. For each species, we quantified relative levels of forest specialization and genetic differentiation among populations. To test the link between forest specialization and susceptibility to forest fragmentation, we assessed species responses to fragmentation by comparing levels of genetic differentiation between continuous and fragmented forest landscapes. Our results revealed a significant and substantial population structure at a very small spatial scale for mobile organisms such as birds. More importantly, we found that specialist species are more affected by forest fragmentation than generalist ones. Finally, our results suggest that even a simple habitat specialization index can be a satisfying predictor of genetic and demographic consequences of habitat fragmentation, providing a reliable practical and quantitative tool for conservation biology. PMID:27314987

  2. Ecological specialisation in habitat selection within a macropodid herbivore guild.

    PubMed

    Garnick, Sarah; Di Stefano, Julian; Elgar, Mark A; Coulson, Graeme

    2016-03-01

    Specialist species show stronger resource selection, narrower niches and lower niche overlap than generalist species. We examined ecological specialisation with respect to habitat selection in a macropodid community comprising the western grey kangaroo Macropus fuliginosus, red-necked wallaby M. rufogriseus and swamp wallaby Wallabia bicolor in the Grampians National Park, Victoria, Australia. We used radio tracking to quantify habitat selection. We predicted that because the fitness benefits of generalisation and specialisation differ, there would be a mix of generalised and specialised species in our community. As all three macropodid species show marked sexual dimorphism, we also expected that they would show sex-based specialisation. Finally, because many large herbivores select different habitats for foraging and resting, we predicted that our species would specialise on a subset of their overall selected habitat based on activity period (diurnal or nocturnal). All three species specialised on the available resources to some degree. Western grey kangaroos were specialists, at least during the active period. Niche data for the two wallaby species were harder to interpret so we could not determine their degree of specialisation. Within species, we found no evidence of sex-based specialisation. However, we found clear evidence of specialisation by activity period in western grey kangaroos and red-necked wallabies, but not in swamp wallabies. The strength of behavioural decisions made during the active period in influencing specialisation points to the likelihood that bottom-up processes regulate this community. PMID:26621691

  3. Quantifying Riverscape Connectivity with Graph Theory

    NASA Astrophysics Data System (ADS)

    Carbonneau, P.; Milledge, D.; Sinha, R.; Tandon, S. K.

    2013-12-01

    Fluvial catchments convey fluxes of water, sediment, nutrients and aquatic biota. At continental scales, crustal topography defines the overall path of channels whilst at local scales depositional and/or erosional features generally determine the exact path of a channel. Furthermore, constructions such as dams, for either water abstraction or hydropower, often have a significant impact on channel networks.The concept of ';connectivity' is commonly invoked when conceptualising the structure of a river network.This concept is easy to grasp but there have been uneven efforts across the environmental sciences to actually quantify connectivity. Currently there have only been a few studies reporting quantitative indices of connectivity in river sciences, notably, in the study of avulsion processes. However, the majority of current work describing some form of environmental connectivity in a quantitative manner is in the field of landscape ecology. Driven by the need to quantify habitat fragmentation, landscape ecologists have returned to graph theory. Within this formal setting, landscape ecologists have successfully developed a range of indices which can model connectivity loss. Such formal connectivity metrics are currently needed for a range of applications in fluvial sciences. One of the most urgent needs relates to dam construction. In the developed world, hydropower development has generally slowed and in many countries, dams are actually being removed. However, this is not the case in the developing world where hydropower is seen as a key element to low-emissions power-security. For example, several dam projects are envisaged in Himalayan catchments in the next 2 decades. This region is already under severe pressure from climate change and urbanisation, and a better understanding of the network fragmentation which can be expected in this system is urgently needed. In this paper, we apply and adapt connectivity metrics from landscape ecology. We then examine the

  4. Habitat associations of juvenile fish at Ningaloo Reef, Western Australia: the importance of coral and algae.

    PubMed

    Wilson, Shaun K; Depczynski, Martial; Fisher, Rebecca; Holmes, Thomas H; O'Leary, Rebecca A; Tinkler, Paul

    2010-12-07

    Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres) 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting) were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and protecting reefs

  5. Habitat Evaluation Procedures (HEP) Report, Pend Oreille Wetlands Wildlife II Project, Technical Report 2002.

    SciTech Connect

    Holmes, Darren

    2003-06-01

    In 2002, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the Pend Oreille Wetlands Wildlife II Project, an acquisition completed by the Kalispel Tribe of Indians in 1997. Evaluation species and appropriate models include bald eagle, black-capped chickadee, Canada goose, mallard, and yellow warbler. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The Pend Oreille Wetlands Wildlife II Project provides a total of 313.91 Habitat Units (HUs) for the species evaluated. Open water habitat provides 16.08 HUs for Canada goose and mallard. Shoreline and island habitat provide 7.36 HUs fore Canada goose and mallard. Wet meadow provides 117.62 HUs for Canada goose and mallard. Scrub-shrub wetlands provide 9.78 HUs for yellow warbler, mallard, and white-tailed deer. Deciduous forested wetlands provide 140.47 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. Conifer forest provides 22.60 HUs for bald eagle, black-capped chickadee, and white-tailed deer. The objective of using HEP at the Pend Oreille Wetlands Wildlife II Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  6. Habitat Evaluation Procedures (HEP) Report; West Beaver Lake Project, Technical Report 2005

    SciTech Connect

    Entz, Ray

    2005-05-01

    On September 7, 2004, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the West Beaver Lake property, an acquisition completed by the Kalispel Tribe of Indians in September 2004. Evaluation species and appropriate models include bald eagle, black-capped chickadee, mallard, muskrat, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The West Beaver Lake Project provides a total of 82.69 Habitat Units (HUs) for the species evaluated. Emergent wetland habitat provides 8.80 HUs for mallard, muskrat, and Canada goose. Conifer forest habitat provides 70.33 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. Open water provides 3.30 HUs for mallard, muskrat, and Canada goose. The objective of using HEP at the West Beaver Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  7. Mapping anuran habitat suitability to estimate effects of grassland and wetland conservation programs

    USGS Publications Warehouse

    Mushet, David M.; Euliss, Ned H.; Stockwell, Craig A.

    2012-01-01

    The conversion of the Northern Great Plains of North America to a landscape favoring agricultural commodity production has negatively impacted wildlife habitats. To offset impacts, conservation programs have been implemented by the U.S. Department of Agriculture and other agencies to restore grassland and wetland habitat components. To evaluate effects of these efforts on anuran habitats, we used call survey data and environmental data in ecological niche factor analyses implemented through the program Biomapper to quantify habitat suitability for five anuran species within a 196 km2 study area. Our amphibian call surveys identified Northern Leopard Frogs (Lithobates pipiens), Wood Frogs (Lithobates sylvaticus), Boreal Chorus Frogs (Pseudacris maculata), Great Plains Toads (Anaxyrus cognatus), and Woodhouse’s Toads (Anaxyrus woodhousii) occurring within the study area. Habitat suitability maps developed for each species revealed differing patterns of suitable habitat among species. The most significant findings of our mapping effort were 1) the influence of deep-water overwintering wetlands on suitable habitat for all species encountered except the Boreal Chorus Frog; 2) the lack of overlap between areas of core habitat for both the Northern Leopard Frog and Wood Frog compared to the core habitat for both toad species; and 3) the importance of conservation programs in providing grassland components of Northern Leopard Frog and Wood Frog habitat. The differences in habitats suitable for the five species we studied in the Northern Great Plains, i.e., their ecological niches, highlight the importance of utilizing an ecosystem based approach that considers the varying needs of multiple species in the development of amphibian conservation and management plans.

  8. Negative effects of habitat loss on survival of migrant Warblers in a forest mosaic.

    PubMed

    Zitske, B P; Betts, M G; Diamond, A W

    2011-10-01

    Habitat loss and fragmentation in forested landscapes often negatively affect animal abundance; however, whether these factors also affect fitness is not well known. We hypothesized that observed decreases in bird occurrence and abundance in landscapes with harvested forests are associated with reduced apparent survival of adults. We defined apparent survival as an estimate of survival that accounts for an imperfect resighting probability, but not permanent emigration (i.e., dispersal). We examined the association between spatially extensive habitat loss and apparent survival of males of 2 Neotropical migrant species, Blackburnian Warbler (Dendroica fusca) and Black-Throated Green Warbler (D. virens), over 7 years in the Greater Fundy Ecosystem, New Brunswick, Canada. We estimated apparent survival among and within breeding seasons. We quantified amount of habitat in the context of individual species. In this landscape, boundaries between land-cover types are gradual rather than clearly identifiable and abrupt. Estimated apparent within-season survival of both species decreased as a function of amount of habitat within a 2000-m radius; survival was approximately 12 times (95% CI 3.43-14) greater in landscapes with 85% habitat than in landscapes with 10% habitat. Apparent annual survival also decreased as a function of amount of habitat within a 100-m radius. Over the range of habitat amount, apparent annual survival decreased 15% (95% CI 7-29%) as the amount of habitat decreased. Our results suggest that reduced species occurrence in landscapes with low proportions of habitat is due partly to lower apparent survival at these sites. This mechanism operates both directly (i.e., via effects on mortality or dispersal during breeding) and possibly through indirect effects during the nonbreeding season. Habitat loss was associated not only with a lower number of individuals, but also with lower survival of those individuals.

  9. Habitat Associations of Juvenile Fish at Ningaloo Reef, Western Australia: The Importance of Coral and Algae

    PubMed Central

    Wilson, Shaun K.; Depczynski, Martial; Fisher, Rebecca; Holmes, Thomas H.; O'Leary, Rebecca A.; Tinkler, Paul

    2010-01-01

    Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres) 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting) were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and protecting reefs

  10. The impacts of mobile fishing gear on seafloor habitats in the Gulf of Maine (Northwest Atlantic): implications for conservation of fish populations

    USGS Publications Warehouse

    Auster, Peter J.; Malatesta, Richard J.; Langton, Richard W.; Watting, Les; Valentine, Page C.; Donaldson, Carol Lee S.; Langton, Elizabeth W.; Shepard, Andrew N.; Babb, War G.

    1997-01-01

    Fishing gear alters seafloor habitats, but the extent of these alterations, and their effects, have not been quantified extensively in the northwest Atlantic. Understanding the extent of these impacts, and their effects on populations of living marine resources, is needed to properly manage current and future levels of fishing effort and fishing power. For example, the entire U.S. side of the Gulf of Maine was impacted annually by mobile fishing gear between 1984 and 1990, based on calculations of area swept by trawl and dredge gear. Georges Bank was imparted three to nearly four times annually during the same period. Studies at three sites in the Gulf of Maine (off Swans Island, Jeffreys Bank, and Stellwagen Bank) showed that mobile fishing gear altered the physical structure (=complexity) of benthic habitats. Complexity was reduced by direct removal of biogenic (e.g., sponges, hydrozoans, bryozoans, amphipod tubes, holothurians, shell aggregates) and‐ sedimentary (e.g., sand waves, depressions) structures. Also, removal of organisms that create.structures (e.g., crabs, scallops) indirectly reduced complexity. Reductions in habitat complexity may lead to increased predation on juveniles of harvested species and ultimately recruitment to the harvestable stock. Because of a lack of reference sites, where use of mobile fishing is prohibited, no empirical studies have yet been conducted on a scale that could demonstrate population level effects of habitat‐management options. If marine fisheries management is to evolve toward an ecosystem or habitat management approach, experiments are required on the effects of habitat change, both anthropogenic and natural.

  11. Conservation planning and monitoring avian habitat

    USGS Publications Warehouse

    Twedt, D.J.; Loesch, C.R.; Bonney, Rick; Pashley, David N.; Cooper, Robert; Niles, Larry

    2000-01-01

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

  12. Choosing among Techniques for Quantifying Single-Case Intervention Effectiveness

    ERIC Educational Resources Information Center

    Manolov, Rumen; Solanas, Antonio; Sierra, Vicenta; Evans, Jonathan J.

    2011-01-01

    If single-case experimental designs are to be used to establish guidelines for evidence-based interventions in clinical and educational settings, numerical values that reflect treatment effect sizes are required. The present study compares four recently developed procedures for quantifying the magnitude of intervention effect using data with known…

  13. Habitat use by giant panda in relation to man-made forest in Wanglang Nature Reserve of China.

    PubMed

    Kang, Dongwei; Wang, Xiaorong; Yang, Hongwei; Duan, Lijuan; Li, Junqing

    2014-12-01

    To evaluate the effectiveness of human restoration in species conservation, in this study, we undertook a field survey of giant panda (Ailuropoda melanoleuca) habitat and man-made forest habitat in Wanglang Nature Reserve of China. Our results revealed that giant panda did not use the man-made forest in this area so far, and that there were significant differences between the giant panda habitat and the man-made forest habitat. Compared with giant panda habitat, the man-made forest habitat was characterized by lower shrub coverage, thinner trees and lower bamboo density. To improve the effectiveness of human restoration, the habitat requirement of giant panda should be fully consider in the whole process of habitat restoration.

  14. Habitat use by giant panda in relation to man-made forest in Wanglang Nature Reserve of China.

    PubMed

    Kang, Dongwei; Wang, Xiaorong; Yang, Hongwei; Duan, Lijuan; Li, Junqing

    2014-12-01

    To evaluate the effectiveness of human restoration in species conservation, in this study, we undertook a field survey of giant panda (Ailuropoda melanoleuca) habitat and man-made forest habitat in Wanglang Nature Reserve of China. Our results revealed that giant panda did not use the man-made forest in this area so far, and that there were significant differences between the giant panda habitat and the man-made forest habitat. Compared with giant panda habitat, the man-made forest habitat was characterized by lower shrub coverage, thinner trees and lower bamboo density. To improve the effectiveness of human restoration, the habitat requirement of giant panda should be fully consider in the whole process of habitat restoration. PMID:25012204

  15. Impacts of forest herbicides on wildlife: Toxicity and habitat alteration

    USGS Publications Warehouse

    Morrison, M.L.; Meslow, E.C.

    1983-01-01

    This paper begins with a review of both laboratory and field studies on tbe possible direct toxic effects of herbicides on terrestrial vertebrates, primarily birds and mammals. Alteration of the palatability of forage and changes in reproductive success are also discussed. Emphasis is placed on the use of herbicides in forestry; studies dealing with agricultural systems are referenced where appropriate. The indirect effects of herbicides on wildlife-habitat are then conceptualized and quantified using data from a 3-year study on effects of phenoxy and glyphosate herbicides on bird and small mammal communities in western Oregon. Data on density and habitat use are presented and compared with data available from other geographic regions.

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  19. Quantifying uncertainty from material inhomogeneity.

    SciTech Connect

    Battaile, Corbett Chandler; Emery, John M.; Brewer, Luke N.; Boyce, Brad Lee

    2009-09-01

    Most engineering materials are inherently inhomogeneous in their processing, internal structure, properties, and performance. Their properties are therefore statistical rather than deterministic. These inhomogeneities manifest across multiple length and time scales, leading to variabilities, i.e. statistical distributions, that are necessary to accurately describe each stage in the process-structure-properties hierarchy, and are ultimately the primary source of uncertainty in performance of the material and component. When localized events are responsible for component failure, or when component dimensions are on the order of microstructural features, this uncertainty is particularly important. For ultra-high reliability applications, the uncertainty is compounded by a lack of data describing the extremely rare events. Hands-on testing alone cannot supply sufficient data for this purpose. To date, there is no robust or coherent method to quantify this uncertainty so that it can be used in a predictive manner at the component length scale. The research presented in this report begins to address this lack of capability through a systematic study of the effects of microstructure on the strain concentration at a hole. To achieve the strain concentration, small circular holes (approximately 100 {micro}m in diameter) were machined into brass tensile specimens using a femto-second laser. The brass was annealed at 450 C, 600 C, and 800 C to produce three hole-to-grain size ratios of approximately 7, 1, and 1/7. Electron backscatter diffraction experiments were used to guide the construction of digital microstructures for finite element simulations of uniaxial tension. Digital image correlation experiments were used to qualitatively validate the numerical simulations. The simulations were performed iteratively to generate statistics describing the distribution of plastic strain at the hole in varying microstructural environments. In both the experiments and simulations, the

  20. Quantifying magma segregation in dykes

    NASA Astrophysics Data System (ADS)

    Yamato, P.; Duretz, T.; May, D. A.; Tartèse, R.

    2015-10-01

    The dynamics of magma flow is highly affected by the presence of a crystalline load. During magma ascent, it has been demonstrated that crystal-melt segregation constitutes a viable mechanism for magmatic differentiation. Moreover, crystal-melt segregation during magma transport has important implications not only in terms of magma rheology, but also in terms of differentiation of the continental crust. However, the influences of the crystal volume percentage (φ), of their geometry, their size and their density on crystal-melt segregation are still not well constrained. To address these issues, we performed a parametric study using 2D direct numerical simulations, which model the ascension of a crystal-bearing magma in a vertical dyke. Using these models, we have characterised the amount of segregation as a function of different physical properties including φ, the density contrast between crystals and the melt phase (Δρ), the size of the crystals (Ac) and their aspect ratio (R). Results show that small values of R do not affect the segregation. In this case, the amount of segregation depends upon four parameters. Segregation is highest when Δρ and Ac are large, and lowest for large pressure gradient (Pd) and/or large values of dyke width (Wd). These four parameters can be combined into a single one, the Snumber, which can be used to quantify the amount of segregation occurring during magma ascent. Based on systematic numerical modelling and dimensional analysis, we provide a first order scaling law which allows quantification of the segregation for an arbitrary Snumber and φ, encompassing a wide range of typical parameters encountered in terrestrial magmatic systems. Although developed in a simplified system, this study has strong implications regarding our understanding of crystal segregation processes during magma transport. Our first order scaling law allows to immediately determine the amount of crystal-melt segregation occurring in any given magmatic

  1. RELATIONSHIPS BETWEEN HABITAT ARRANGEMENT AND JUVENILE WINTER FLOUNDER DENSITY IN NARRAGANSETT BAY

    EPA Science Inventory

    We used aerial photography in conjunction with a 1-m beam trawl attached to a videocamera with GPS overwrite and a YSI water quality logger to quantify fish densities and characterize habitats in Narragansett Bay and in Rhode Island's coastal lagoons. We compared fish counts fro...

  2. USE OF VIDEO TO ACCESS JUVENILE WINTER FLOUNDER DENSITIES AND HABITATS

    EPA Science Inventory

    We used a digital video camera mounted to a 1-m beam trawl together with an attached continuous recording YSI sonde and a GPS unit to quantify juvenile winter flounder (Pseudopleuronectes americanus) densities and fish habitat in Narragansett Bay, RI. The YSI sonde measured te...

  3. Lake shore and littoral habitat structure: a field survey method and its precision

    EPA Science Inventory

    Until recently, lake physical habitat assessment has been and underemployed tool for assessing lake and reservoir ecological condition. Herein, we outline and evaluate a rapid (2 persons: 1.5-3.5 h) field sampling and analytical approach for quantifying near-shore physical habit...

  4. Umatilla Basin Habitat Improvement Project.

    SciTech Connect

    Bailey, Timothy D.

    1990-01-01

    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.

  5. Habitat Suitability Index Models: Mink

    USGS Publications Warehouse

    Allen, Arthur W.

    1983-01-01

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

  6. Lunar Habitat Airlock/Suitlock

    NASA Technical Reports Server (NTRS)

    Griffin, Brand Norman

    2008-01-01

    Airlocks for lunar Extravehicular Activity (EVA) will be significantly different than previous designs. Until now, airlocks operated infrequently and only in the "clean" weightless environment, but lunar airlocks are planned to be used much more often (every other day) in a dusty, gravity environment. Concepts for airlocks were analyzed by the NASA, JSC Habitability Focus Element during recent lunar outpost studies. Three airlock types were identified; an Airlock (AL) or independent pressure vessel with one hatch to the outside and the other to the Habitat. A Suitlock (SL) which shares a pressure bulkhead with the Habitat allowing rear-entry suits to remain on the dusty side while the crew enters/exits the Habitat. The third option is the Suitport (SP) which offers direct access from the habitable volume into an externally mounted suit. The SP concept was not compared, however between the AL and SL, the AL was favored.

  7. Channel dynamics and habitat complexity in a meandering, gravel-bed river

    NASA Astrophysics Data System (ADS)

    Harrison, L. R.; Legleiter, C. J.; Pecquerie, L.; Dunne, T.

    2009-12-01

    River channel dynamics play an important role in creating and maintaining diverse habitat conditions for multiple life stages of aquatic organisms. As a result, many river restoration projects seek to re-establish ecosystems in which an enhanced degree of habitat complexity is sustained through natural fluvial processes of flow, sediment transport, and channel change. Few field cases have effectively quantified the evolution of channel morphology and habitat complexity in restored rivers, however, and the outcomes of restoration actions remain difficult to predict. Our objective was to quantify the extent to which morphology, flow complexity and salmonid spawning and rearing habitat develop from the simplified initial conditions commonly observed in re-configured meandering channels. Using a time-series of topographic data, we measured rates of morphologic change in a recently restored gravel-bed reach of the Merced River, California, USA. We constructed two-dimensional (2D) hydrodynamic models to quantify how the evolving morphology influenced hydraulic conditions, flow complexity and suitability for Chinook salmon spawning and rearing. Following two large flood events, point bar development led to order-of-magnitude increases in modeled flow complexity, as quantified via the metrics of kinetic energy gradient, vorticity and hydraulic strain. On a bend-averaged scale, morphologic changes produced up to a two-fold increase in flow circulation, indicating a direct linkage between geomorphic processes and the development of habitat complexity at both the local (1.0 m2 grid cell) and meander wavelength scale. Habitat modeling indicated that the availability of Chinook salmon spawning habitat has increased over time, whereas the majority of the reach provides low-medium quality rearing habitat for juvenile salmonids, primarily due to a lack of low velocity refuge zones. These results demonstrate the ability of geomorphic processes to increase flow complexity and

  8. Quantifying Flaw Characteristics from IR NDE Data

    SciTech Connect

    Miller, W; Philips, N R; Burke, M W; Robbins, C L

    2003-02-14

    Work is presented which allows flaw characteristics to be quantified from the transient IR NDE signature. The goal of this effort was to accurately determine the type, size and depth of flaws revealed with IR NDE, using sonic IR as the example IR NDE technique. Typically an IR NDE experiment will result in a positive qualitative indication of a flaw such as a cold or hot spot in the image, but will not provide quantitative data thereby leaving the practitioner to make educated guesses as to the source of the signal. The technique presented here relies on comparing the transient IR signature to exact heat transfer analytical results for prototypical flaws, using the flaw characteristics as unknown fitting parameters. A nonlinear least squares algorithm is used to evaluate the fitting parameters, which then provide a direct measure of the flaw characteristics that can be mapped to the imaged surface for visual reference. The method uses temperature data for the heat transfer analysis, so radiometric calibration of the IR signal is required. The method provides quantitative data with a single thermal event (e.g. acoustic pulse or flash), as compared to phase-lock techniques that require many events. The work has been tested with numerical data but remains to be validated by experimental data, and that effort is underway.

  9. Effects of Mitigative Measures on Productivity of White Sturgeon Populations in the Columbia River Downstream from McNary Dam: Determine Status and Habitat Requirements of White Sturgeon Populations in the Columbia and Snake Rivers Upstream from McNary Dam, 1997-1998 Annual Report.

    SciTech Connect

    Ward, David L.

    1999-02-01

    The authors report on their progress from April 1997 through March 1998 on determining the effects of mitigative measures on productivity of white sturgeon populations in the Columbia River downstream from McNary Dam, and on determining the status and habitat requirements of white sturgeon populations in the Columbia and Snake rivers upstream from McNary Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW; Report A), Washington Department of Fish and Wildlife (WDFW; Report B), U.S. Geological Survey Biological Resources Division (USGS; Report C), National Marine Fisheries Service (NMFS; Report D), U.S. Fish and Wildlife Service (USFWS; Report E), and Columbia River Inter-Tribal Fish Commission (CRITFC; Report F). This is a multi-year study with many objectives requiring more than one year to complete. Therefore, findings from a given year may be part of more significant findings yet to be reported. Highlights of results of the work from April 1997 through March 1998 listed.

  10. 77 FR 12543 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Riverside Fairy Shrimp

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-01

    ... FR 31686), our DEA of the proposed revised designation, and the amended required determinations... critical habitat rule (76 FR 31686; June 1, 2011); (b) Areas containing the physical and biological... revise critical habitat (76 FR 31686) for further discussion. (9) Any probable economic,...

  11. 78 FR 49831 - Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... designation does not require implementation of restoration, recovery, or enhancement measures by non-Federal... July 1, 1994 (59 FR 34271)), the Information Quality Act (section 515 of the Treasury and General...' habitat, ecology, and life histories as described below--(see Habitat and Life History section of...

  12. Modeling trade-offs between plant fiber and toxins: a framework for quantifying risks perceived by foraging herbivores.

    PubMed

    Camp, Meghan J; Shipley, Lisa A; Johnson, Timothy R; Forbey, Jennifer Sorensen; Rachlow, Janet L; Crowell, Miranda M

    2015-12-01

    When selecting habitats, herbivores must weigh multiple risks, such as predation, starvation, toxicity, and thermal stress, forcing them to make fitness trade-offs. Here, we applied the method of paired comparisons (PC) to investigate how herbivores make trade-offs between habitat features that influence selection of food patches. The method of PC measures utility and the inverse of utility, relative risk, and makes trade-offs and indifferences explicit by forcing animals to make choices between two patches with different types of risks. Using a series of paired-choice experiments to titrate the equivalence curve and find the marginal rate of substitution for one risk over the other, we evaluated how toxin-tolerant (pygmy rabbit Brachylagus idahoensis) and fiber-tolerant (mountain cottontail rabbit Sylviagus nuttallii) herbivores differed in their hypothesized perceived risk of fiber and toxins in food. Pygmy rabbits were willing to consume nearly five times more of the toxin 1,8-cineole in their diets to avoid consuming higher levels of fiber than were mountain cottontails. Fiber posed a greater relative risk for pygmy rabbits than cottontails and cineole a greater risk for cottontails than pygmy rabbits. Our flexible modeling approach can be used to (1) quantify how animals evaluate and trade off multiple habitat attributes when the benefits and risks are difficult to quantify, and (2) integrate diverse risks that influence fitness and habitat selection into a single index of habitat value. This index potentially could be applied to landscapes to predict habitat selection across several scales.

  13. Quantifying the distribution and abundance of rippled scour depressions (RSDs) on the seafloor of California's continental margin using autoclassfication models

    NASA Astrophysics Data System (ADS)

    Davis, A. C.; Mueller, C.; Hallenbeck, T.; Carrillo, J.; Gomez, J.

    2010-12-01

    The California Seafloor Mapping Project (CSMP) is a cooperative initiative creating a comprehensive, high-resolution (2-5m) coastal/marine geologic and habitat base map for all of California’s State waters (Mean high water to three nautical miles). This massive dataset covering > 8500 sq. km of coastal seafloor is enabling researchers to study patterns and distribution of near shore habitats and geomorphology on a scale never before possible. Data from CSMP reveal the presence of rippled scour depressions (RSD) as the most prominent features on the continental shelf. These features are found worldwide and are characterized as depressions (.4m-1m) of coarse grain sediment and long period sand waves surrounded by a fine sediment plateau. While previous studies have described the geomorphologies of RSDs and speculated on their origin, this is the first regional study describing their patterns of abundance and distribution on a scale of 1000s of km. The purpose of this study is to use auto classification methods to quantify the spatial extent and distribution of three benthic habitats (rock, sediment, RSD) within the state waters of California. Using CSMP acoustic backscatter imagery and derived bathymetric products (rugosity, bathymetric position index, and slope), we developed a habitat classification model in ArcGIS to assign benthic habitat into one of these three classes. These results will then be used to quantify and characterize spatial patterns in the distribution and abundance of these habitats along the California continental margin.

  14. The disentangled bank: how loss of habitat fragments and disassembles ecological networks.

    PubMed

    Gonzalez, Andrew; Rayfield, Bronwyn; Lindo, Zoë

    2011-03-01

    Habitat transformation is one of the leading causes of changes in biodiversity and the breakdown of ecosystem function and services. The impacts of habitat transformation on biodiversity are complex and can be difficult to test and demonstrate. Network approaches to biodiversity science have provided a powerful set of tools and models that are beginning to present new insight into the structural and functional effects of habitat transformation on complex ecological systems. We propose a framework for studying the ways in which habitat loss and fragmentation jointly affect biodiversity by altering both habitat and ecological interaction networks. That is, the explicit study of "networks of networks" is required to understand the impacts of habitat change on biodiversity. We conduct a broad review of network methods and results, with the aim of revealing the common approaches used by landscape ecology and community ecology. We find that while a lot is known about the consequences of habitat transformation for habitat network topology and for the structure and function of simple antagonistic and mutualistic interaction networks, few studies have evaluated the consequences for large interaction networks with complex and spatially explicit architectures. Moreover, almost no studies have been focused on the continuous feedback between the spatial structure and dynamics of the habitat network and the structure and dynamics of the interaction networks inhabiting the habitat network. We conclude that theory and experiments that tackle the ecology of networks of networks are needed to provide a deeper understanding of biodiversity change in fragmented landscapes.

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

    PubMed

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

    2013-01-01

    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.

  16. A method for quantifying consistency in animal distributions using survey data.

    PubMed

    Heath, Joel P; Montevecchi, William A; Esler, Daniel

    2012-01-01

    The degree of consistency with which groups of animals use the landscape is determined by a variety of ecological processes that influence their movements and patterns of habitat use. We developed a technique termed Distributional Consistency that uses survey data of unmarked individuals to quantify temporal consistency in their spatial distribution, while accounting for changes in population size. Distributional consistency is quantified by comparing the observed distribution patterns to all theoretically possible distribution patterns of observed individuals, leading to a proportional score between 0 and 1, reflecting increasingly consistent use of sites within a region. The technique can be applied to survey data for any taxa across a range of spatial and temporal scales. We suggest ways in which distributional consistency could provide inferences about the dispersal and habitat decisions of individuals, and the scales at which these decisions operate. Distributional consistency integrates spatial and temporal processes to quantify an important characteristic of different habitats and their use by populations, which in turn will be particularly useful in complimenting and interpreting other ecological measures such as population density and stability. The technique can be applied to many existing data sets to investigate and evaluate a range of important ecological questions using simple survey data.

  17. EXAMINING ASSOCIATIONS BETWEEN FISH ASSEMBLAGES AND PHYSICAL HABITAT

    EPA Science Inventory

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

  18. HABITAT ASSESSMENT MODELS FOR BAY SCALLOP, ARGOPECTEN IRRADIANS

    EPA Science Inventory

    Bay scallops (Argopecten irradians) inhabit shallow subtidal habitats along the Atlantic coast of the United States and require settlement substrates, such as submerged aquatic vegetation (SAV), for their early juvenile stages. The short lifespan of bay scallops (1-2 yr) coupled...

  19. Extreme habitats as refuge from parasite infections? Evidence from an extremophile fish

    NASA Astrophysics Data System (ADS)

    Tobler, Michael; Schlupp, Ingo; García de León, Francisco J.; Glaubrecht, Matthias; Plath, Martin

    2007-05-01

    Living in extreme habitats typically requires costly adaptations of any organism tolerating these conditions, but very little is known about potential benefits that trade off these costs. We suggest that extreme habitats may function as refuge from parasite infections, since parasites can become locally extinct either directly, through selection by an extreme environmental parameter on free-living parasite stages, or indirectly, through selection on other host species involved in its life cycle. We tested this hypothesis in a small freshwater fish, the Atlantic molly ( Poecilia mexicana) that inhabits normal freshwaters as well as extreme habitats containing high concentrations of toxic hydrogen sulfide. Populations from such extreme habitats are significantly less parasitized by the trematode Uvulifer sp. than a population from a non-sulfidic habitat. We suggest that reduced parasite prevalence may be a benefit of living in sulfidic habitats.

  20. Seasonal variation