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The article focuses on field surveys of stream-scale habitat, examining basin-scale habitat with the use of Geographic Information System for 27 streams where two subspecies of cutthroat trout were translocated in Colorado and New Mexico. Information about the use of polytomous logistic regression to develop models predicting three categories of cutthroat trout translocation success from habitat attributes is presented.

A major challenge facing conservation biologists and wildlife managers is to predict how fauna will respond to habitat loss. Different species require different amounts of habitat for population persistence, and species' reproductive rates have been identified as one of the major factors affecting these habitat-amount requirements. The purpose of this study was to test the prediction that species with higher reproductive rates require less habitat for population persistence than species with lower reproductive rates. We used 41 species of forest breeding birds to test for a relationship between the annual reproductive output and the amount of forest cover at which each species has a 50% probability of presence in the landscape. To look at the presence of species over landscapes with varying amounts of forest cover, we combined two large-scale independent data sets: the North American Breeding Bird Survey and the U.S. Geological Survey (USGS) Land Use and Land Cover (LULC) digital data. Species presence/absence information was determined over a 10-year window for 779 circular landscapes that surround each Breeding Bird Survey route in the central and eastern USA region. Annual reproductive rates were obtained from the literature. There was a significant negative (interspecies) relationship between the estimated minimum habitat amount at which there was a 50% probability of presence in the landscape and annual reproductive output (F[SUB]1,39[SUB] = 7.71, P = 0.008, r[SUP]2[SUP] = 0.16). This is the first direct test for a negative relationship between minimum habitat requirements and annual reproductive rates. [ABSTRACT FROM AUTHOR]

Predicting potential habitat across a landscape for rare species is extremely challenging. However, partitioned Mahalanobis D² methods avoid pitfalls commonly encountered when surveying rare species by using data collected only at known species locations. Minimum habitat requirements are then determined by examining a principal components analysis to find consistent habitat characteristics across known locations. We used partitioned D² methods to examine minimum habitat requirements of Indiana bats (Myotis sodalis) in the Champlain Valley of Vermont and New York, USA, across 7 spatial scales and map potential habitat for the species throughout the same area. We radiotracked 24 female Indiana bats to their roost trees and across their nighttime foraging areas to collect habitat characteristics at 7 spatial scales: 1) roost trees, 2) 0.1-ha circular plots surrounding the roost trees, 3) home ranges, and 4-7) 0.5-km, 1-km, 2-km, and 3-km buffers surrounding the roost tree. Roost trees (n = 50) typically were tall, dead, large-diameter trees with exfoliating bark, located at low elevations and close to water. Trees surrounding roosts typically were smaller in diameter and shorter in height, but they had greater soundness than the roost trees. We documented 14 home ranges in areas of diverse, patchy land cover types that were close to water with east-facing aspects. Across all landscape extents, area of forest within roost-tree buffers and the aspect across those buffers were the most consistent features. Predictive maps indicated that suitable habitat ranged from 4.7-8.1% of the area examined within the Champlain Valley. These habitat models further understanding of Indiana bat summer habitat by indicating minimum habitat characteristics at multiple scales and can be used to aid management decisions by highlighting potential habitat. Nonetheless, information on juvenile production and recruitment is lacking; therefore, assessments of Indiana bat habitat quality in the region are still incomplete. [ABSTRACT FROM AUTHOR]

The Hamilton Harbour Remedial Action Plan has adopted a dissolved oxygen goal for restoring habitat in the pelagic portion of Hamilton Harbour based on the ecological needs of Cisco (Coregonus artedii), a fish formerly abundant in Hamilton Harbour. The goal for dissolved oxygen is based on retaining an adequate volume of optimum Cisco habitat characterized as temperature <20°C and dissolved oxygen >6 mg l−1during the June to September period. The goal also specifies minimum habitat requirements for when optimum conditions are not achieved, that being a smaller volume of refuge habitat with temperature <20°C and dissolved oxygen >3 mg l−1for no more than 2 weeks per year. Weekly temperature and dissolved oxygen profiles during May to October, 1987 to 2012 in the center of Hamilton Harbour were assessed to evaluate optimum and refuge Cisco habitat relative to the Remedial Action Plan goal for dissolved oxygen. This goal was met only in 2009. However, this was fortuitous, based on a combination of cooler water temperatures in May and June and exchanges of cool oxygenated water from Lake Ontario. From 1987 to 2002 optimum habitat was estimated to be absent at least one week and up to seven weeks during June to September. Cisco could not have survived in Hamilton Harbour during six of these years when refuge habitat was absent for one or two weeks. Since 2003, Cisco habitat in Hamilton Harbour improved markedly, as some refuge habitat was always present. As well, the number of weeks with inadequate refuge habitat, and with no optimum habitat has declined. These improvements in Cisco habitat since 2003 were related to higher dissolved oxygen in the mid-depths of Hamilton Harbour. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reproductive rate has been suggested to have a positive effect on the amount of habitat loss a species can tolerate while emigration from habitat patches has been suggested to have both positive and negative effects. Forest fragmentation has been suggested to have negative effects on forest species. We determined the extinction threshold for 12 species of saproxylic (dead wood dependent) longhorned beetles (Coleoptera: Cerambycidae) using trap catch data from Ontario, Canada. We also determined the maximum egg production of each species and whether they were likely to move outside of forest patches. We found a strong negative relationship between reproductive rate and the minimum habitat amount required for species presence. This relationship is obscured if the scale of investigation is not appropriate for the study organism. As well, species caught moving outside forest habitat had lower extinction thresholds than species not caught moving outside forest but this was not significant after accounting for reproductive rate. Fragmentation did not have an effect on the minimum habitat requirements. These relationships can inform predictions of which species will be most affected by habitat loss. [ABSTRACT FROM AUTHOR]

Mahalanobis Distance (D²) Statistic is a multivariate statistical method that has been used to model habitats occupied by wildlife and plant species. The output, whether standardized squared distance or probability values, represents the similarity of a given set of values with those of an optimum habitat configuration defined exclusively by sites where the species of interest is known to occur. Typically, all principal components with nonzero eigenvalues are used to calculate D² values. We partitioned D² into contributions from individual principal components (PCs) and selected PCs corresponding to relatively invariant aspects of the environment across all use sites to formulate D²(k). Partitioned Mahalanobis D²(k) represents the similarity of a given set of values with those of "minimum" habitat requirements of the species as defined by occupied sites using the k subset of principal components. We created a GIS-based model of the habitat surrounding 39 confirmed timber rattlesnake hibernacula on the Madison County Wildlife Management Area in northwest Arkansas, USA, using slope, aspect, elevation, and 11 physical soil attributes. We retained 4 of 15 principal components in D²(k = 4) calculations, and minimum habitat requirements corresponded to a combination of moderate slope, south to southwest facing slopes, and medium to high elevations. We used bootstrap and cross-validation techniques to examine the stability of the correlation matrix and the effect of each site on overall D²(k) values. The D²(k = 4) model specifically highlighted habitats similar to known rattlesnake hibernacula. We present a method to translate the probability surface into a qualitative data layer useful in making management decisions by examining the cumulative distributions of the percentages of (1) hibernacula correctly classified and (2) the study area predicted. We selected the probability threshold that maximized the predictive gain by... [ABSTRACT FROM AUTHOR]

Headwater streams support vital aquatic habitat yet are vulnerable to changing climate due to their high elevation and small size. Coldwater fish are especially sensitive to the altered streamflow and water temperature regimes during summer low flow periods. Though previous studies have provided insights on how changes in climate and alterations in stream discharge may affect habitat availability for various native cutthroat trout species, suitable physical habitats have not been evaluated under future climate projections for the threatened Greenback Cutthroat Trout (GBCT) native to headwater regions of Colorado, USA. Thus, this study used field data collected from selected headwater streams across the current distribution of GBCT to construct one‐dimensional hydraulic models to evaluate streamflow and physical habitat under four future climate projections. Results illustrate reductions in both predicted streamflow and physical habitat for all future climate projections across study sites. The projected mean summer streamflow shows greater decline (−52% on average) compared to the projected decline in mean August flow (−21% on average). Moreover, sites located at a relative higher elevation with larger substrate and steeper slope were projected to experience more reductions in physical habitat due to streamflow reductions. Specifically, streams with step‐pool morphologies may experience grater changes in available habitat compared to pool‐riffle streams. Future climate change studies related to coldwater fish that examine spatial variation in flow alteration could provide novel data to complement the existing literature on the thermal characteristics. Tailoring reintroduction and management efforts for GBCT to the individual headwater stream with adequate on‐site monitoring could provide a more holistic conservation approach. [ABSTRACT FROM AUTHOR]

Salmonids are of immense socio‐economic importance in much of the world, but are threatened by climate change. This has generated a substantial literature documenting the effects of climate variation on salmonid productivity in freshwater ecosystems, but there has been no global quantitative synthesis across studies. We conducted a systematic review and meta‐analysis to gain quantitative insight into key factors shaping the effects of climate on salmonid productivity, ultimately collecting 1321 correlations from 156 studies, representing 23 species across 24 countries. Fisher's Z was used as the standardized effect size, and a series of weighted mixed‐effects models were compared to identify covariates that best explained variation in effects. Patterns in climate effects were complex and were driven by spatial (latitude, elevation), temporal (time‐period, age‐class), and biological (range, habitat type, anadromy) variation within and among study populations. These trends were often consistent with predictions based on salmonid thermal tolerances. Namely, warming and decreased precipitation tended to reduce productivity when high temperatures challenged upper thermal limits, while opposite patterns were common when cold temperatures limited productivity. Overall, variable climate impacts on salmonids suggest that future declines in some locations may be counterbalanced by gains in others. In particular, we suggest that future warming should (1) increase salmonid productivity at high latitudes and elevations (especially >60° and >1500 m), (2) reduce productivity in populations experiencing hotter and dryer growing season conditions, (3) favor non‐native over native salmonids, and (4) impact lentic populations less negatively than lotic ones. These patterns should help conservation and management organizations identify populations most vulnerable to climate change, which can then be prioritized for protective measures. Our framework enables broad inferences about future productivity that can inform decision‐making under climate change for salmonids and other taxa, but more widespread, standardized, and hypothesis‐driven research is needed to expand current knowledge. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Fisheries & Aquatic Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate change and habitat loss have been identified as the main causes of species extinction. Forest regeneration and protected areas are essential to buffer climate change impacts and to ensure quality habitats for threatened species. We assessed the current and future environmental suitability for the maned sloth, Bradypus torquatus , under both future climate and forest restoration scenarios, using ecological niche modeling. We compared environmental suitability for two Evolutionarily Significant Units (ESUnorth and ESUsouth) using two climate change scenarios for 2070, and three potential forest regeneration scenarios. Likewise, we evaluated the protection degree of the suitable areas resulting from the models, according to Brazilian law: PA—Protected Areas; PPA—Permanent Protection Areas (environmentally sensitive areas in private properties); and LR—Legal Reserves (natural vegetation areas in private properties). Finally, we calculated the deficit of PPA and LR in each ESU, considering the current forest cover. Forest regeneration might mitigate the deleterious effects of climate change by maintaining and increasing environmental suitability in future scenarios. The ESUnorth contains more suitable areas (21,570 km²) than the ESUsouth (12,386 km²), with an increase in all future scenarios (up to 45,648 km² of new suitable areas), while ESUsouth might have a significant decrease (up to 7,546 km² less). Suitable areas are mostly unprotected (ESUnorth—65.5% and ESUsouth—58.3%). Therefore, PPA and PA can maintain only a small portion of current and future suitable areas. Both ESUs present a high deficit of PPA and LR, highlighting the necessity to act in the recovery of these areas to accomplish a large-scale restoration, mitigate climate change effects, and achieve, at least, a minimum forested area to safeguard the species. Notwithstanding, a long-term conservation of B. torquatus will benefit from forest regeneration besides those minimum requirements, allied to the protection of forest areas. [ABSTRACT FROM AUTHOR]

Wetland birds are undergoing severe population declines in North America, with habitat degradation and wetland loss considered two of the primary causes. Due to the cryptic nature of many wetland bird species, the ecological conditions (e.g., matrix composition) that influence bird occupancy, and the relevant spatial scales at which to measure bird responses, remain unclear but may affect inference about wetland use and suitability. We conducted wetland bird surveys at 477 points across northeastern Illinois and northwestern Indiana within the highly urbanized landscape surrounding Chicago. Using remotely sensed land cover data, we built occupancy models for 10 wetland bird species (American Coot Fulica americana, Black‐crowned Night‐Heron Nycticorax nycticorax, Blue‐winged Teal Anas discors, Common Gallinule Gallinula galeata, Least Bittern Ixobrychus exilis, Marsh Wren Cistothorus palustris, Pied‐billed Grebe Podilymbus podiceps, Sora Porzana carolina, Swamp Sparrow Melospiza georgiana, and Virginia Rail Rallus limicola) to quantify their responses to wetland cover types (emergent wetland, forested wetland, riverine wetland, and freshwater pond) and urbanization at four spatial scales (200‐, 400‐, 800‐, and 2000‐m radial distances). We also included the distance to Lake Michigan as a covariate in occupancy models to account for ecological differences between coastal and inland wetlands. We found that relationships between land cover types and occupancy differed by species, as did the spatial scale of support. Generally, the presence of emergent wetlands or ponds at immediate (200 m) and local (400 m) spatial scales within the surrounding matrix was positively associated with wetland bird occupancy. Contrary to expectations, we did not find support for a negative relationship between urbanization and occupancy for most focal species, indicating that birds are using available wetland habitats despite surrounding development. While future research should evaluate management strategies at the watershed scale, our findings suggest that wetland conservation planning at immediate and local scales is likely to promote bird habitat use within highly modified landscapes of the Upper Midwestern United States. [ABSTRACT FROM AUTHOR]

Abstract: This paper is based on a study conducted by Sasakawa International Center for Space Architecture (SICSA) between September 2008 and February 2009. SICSA has been awarded key roles in helping two aerospace company teams plan living and working accommodations for early lunar surface missions. SICSA has major conceptual design responsibilities on teams headed by Boeing and ILC-Dover which were separately selected out of more than 20 competing proposals for two out of three total NASA study contracts. Major study priorities were to determine minimum habitat requirements essential to keep crews alive and safe from harm during the first month-long missions, and then expand these accommodations as operations, facilities and amenities are extended. This paper discusses important points of radiation protection design options and known radiation protection materials applications with a special emphasis upon comparative mass implications for several proposed habitat configuration concepts. These comparisons are correlated with shielding surface area rather than actual mass estimates due to current data uncertainties regarding a number of issues: unresolved questions concerning how much radiation protection will be mandated, what mitigation strategies will be selected, what types and thicknesses of materials will be used, and how much of the total allowable module mass can be allocated for this purpose. [ABSTRACT FROM AUTHOR]

Quantitative relationships between river discharge and hydraulic habitat availability for key taxa are important elements of environmental flow assessment. We used radiotelemetry to examine diel patterns of habitat use by tracking the locations of 17 juvenile Sooty grunter (Hephaestus fuliginosus) over a 10‐day period during the late dry season in a river in the wet–dry tropics of northern Australia. Habitat use data were integrated with a hydrodynamic model to identify preferred hydraulic habitat and explore different river discharge scenarios to assess the potential effects of water abstraction on habitat availability. Sooty grunter exhibited a strong preference for shallow, fast flowing mesohabitat (riffles and runs). Hydraulic microhabitat preference was modelled using generalised additive mixed‐effect models (GAMMs) and showed no significant difference in microhabitat selection between day and night. Habitat criteria developed from a combined day‐night GAMM were defined as locations with velocities of 0.26–1.42 m s−1 and depths <0.69 m. Hydrodynamic modelling of river discharge scenarios in the study reach showed that the area of preferred habitat was highest at 8 m3 s−1, with large declines in habitat area under low flows (61% decline in habitat area at 0.5 m3 s−1 compared to the discharge of 2.8 m3 s−1 at the time of radio‐tracking). While the study focusses on a single species, our findings demonstrate the broad applicability of radiotelemetry as a means of quantifying the diel hydraulic habitat requirements of riverine fish to support the objective determination of environmental flow regimes. [ABSTRACT FROM AUTHOR]

Aim: Conserving stream biota could require strategies that preserve habitats conveying resistance to ecological impacts of changing land use and climate. Retrospective analyses of species' responses to anthropogenic disturbances can inform such strategies. We developed a hierarchical framework to contrast environmental conditions underlying persistence versus extirpation of an imperilled stream fish, Candy Darter (Etheostoma osburni), over decades of changing land use. The decline of E. osburni may broadly represent the challenge of conserving sensitive freshwater species in intensively used upland environments. Location: New River drainage, Appalachian Mountains, USA. Methods: We surveyed fish and habitat in historically occupied sites to identify population refugia, and used multivariate and spatial analyses to address three questions: (a) what are the environmental correlates of refugia? (b) are the pathways by which land use impacts instream habitat constrained by catchment‐ and/or segment‐scale features? and (c) are E. osburni distributional dynamics spatially structured and explained by fine sediment and warm stream temperatures? Results: We confirmed a recently localized distribution similar to other upland species, marked by at least seven extirpations from streams throughout E. osburni's southern range. Catchment‐scale features primarily constrained land use and finer‐scale habitat, leading to either extirpations or population‐supporting refugia defined by features at multiple scales. Refugium habitats contained cooler temperatures and less fine sediment. Rare mismatches between persistence and habitat suitability were explained by network location, suggesting unmeasured environmental gradients and/or dispersal contributed to distributional dynamics. Main conclusions: We provided insight at multiple spatial scales into how aquatic species' distributions become fragmented and localized. Our results demonstrate that natural landscape heterogeneity imparts spatially variable resistance of sensitive species to intensive land uses. By recognizing the scale‐specific features that buffer populations from extirpation, conservation strategies could be tailored to protect naturally occurring refugium habitats and focus restoration in systems where such habitats are broadly lacking. [ABSTRACT FROM AUTHOR]

Landscape connectivity is integral to the persistence of metapopulations of wide ranging carnivores and other terrestrial species. The objectives of this research were to investigate the landscape characteristics essential to use of areas by lynx and bobcats in northern New England, map a habitat availability model for each species, and explore connectivity across areas of the region likely to experience future development pressure. A Mahalanobis distance analysis was conducted on location data collected between 2005 and 2010 from 16 bobcats in western Vermont and 31 lynx in northern Maine to determine which variables were most consistent across all locations for each species using three scales based on average 1) local (15 minute) movement, 2) linear distance between daily locations, and 3) female home range size. The bobcat model providing the widest separation between used locations and random study area locations suggests that they cue into landscape features such as edge, availability of cover, and development density at different scales. The lynx model with the widest separation between random and used locations contained five variables including natural habitat, cover, and elevation—all at different scales. Shrub scrub habitat—where lynx’s preferred prey is most abundant—was represented at the daily distance moved scale. Cross validation indicated that outliers had little effect on models for either species. A habitat suitability value was calculated for each 30 m2 pixel across Vermont, New Hampshire, and Maine for each species and used to map connectivity between conserved lands within selected areas across the region. Projections of future landscape change illustrated potential impacts of anthropogenic development on areas lynx and bobcat may use, and indicated where connectivity for bobcats and lynx may be lost. These projections provided a guide for conservation of landscape permeability for lynx, bobcat, and species relying on similar habitats in the region. [ABSTRACT FROM AUTHOR]

Faunal responses to anthropogenic habitat modification represent an important aspect of global change. In Puerto Rico, two species of arboreal lizard, Anolis cristatellus and A. stratulus, are commonly encountered in urban areas, yet seem to use the urban habitat in different ways. In this study, we quantified differences in habitat use between these two species in an urban setting. For each species, we measured habitat use and preference, and the niche space of each taxon, with respect to manmade features of the urban environment. To measure niche space of these species in an urban environment, we collected data from a total of six urban sites across four different municipalities on the island of Puerto Rico. We quantified relative abundance of both species, their habitat use, and the available habitat in the environment to measure both microhabitat preference in an urban setting, as well as niche partitioning between the two different lizards. Overall, we found that the two species utilize different portions of the urban habitat. Anolis stratulus tends to use more 'natural' portions of the urban environment (i.e., trees and other cultivated vegetation), whereas A. cristatellus more frequently uses anthropogenic structures. We also found that aspects of habitat discrimination in urban areas mirror a pattern measured in prior studies for forested sites in which A. stratulus was found to perch higher than A. cristatellus and preferred lower temperatures and greater canopy cover. In our study, we found that the multivariate niche space occupied by A. stratulus did not differ from the available niche space in natural portions of the urban environment and in turn represented a subset of the niche space occupied by A. cristatellus. The unique niche space occupied by A. cristatellus corresponds to manmade aspects of the urban environment generally not utilized by A. stratulus. Our results demonstrate that some species are merely tolerant of urbanization while others utilize urban habitats in novel ways. This finding has implications for long-term persistence in urban habitats and suggests that loss of natural habitat elements may lead to nonrandom species extirpations as urbanization intensifies. [ABSTRACT FROM AUTHOR]

Context: Many studies dichotomize habitat selection into 'local' or 'landscape' effects, with little explanation regarding what each represents. Ambiguous use of these terms across studies may confound observations of selection operating across different spatiotemporal resolutions and impede synthesis of scale-dependent habitat selection. Objective: To examine the consistency of use of the terms 'local' and 'landscape' level habitat selection and evaluate potential implications for conservation science. Methods: We reviewed 136 multi-level studies observing local and/or landscape effects. From each study, we identified which of Johnson's (Ecology 61:65-71, 1980) selection orders was observed at the local and landscape scale. We assessed consistency in the selection order observed at each scale. Results: At the local scale, 54% of studies observed 3rd order selection and 38% of studies observed 4th order selection. At the landscape scale, 64% of studies observed 2nd order selection, while only 8% of studies observed 1st order selection. Overlap also occurred; 2nd order selection was observed at the local scale in 8% of studies, while 3rd and 4th order selection was observed at the landscape scale in 24 and 3% of studies, respectively. Conclusions: Selection orders observed at local and landscape scales are inconsistent across studies, making comparisons and synthesis difficult. This inconsistency makes the terms 'local' and 'landscape' meaningless, and may lead to misidentification of limiting factor(s) most important for conservation efforts. Dichotomous terms should no longer be used in reference to levels of selection, but in reference to specific explanatory variables whose characteristic scale(s) best fit the appropriate definition. [ABSTRACT FROM AUTHOR]

Climate-driven shrub expansion is altering the distribution of animal communities in the Arctic. A better understanding of habitat requirements is needed to accurately predict the response of herbivore communities to shrub expansion. We examined patterns of browsing by moose ( Alces alces), snowshoe hare ( Lepus americanus), and ptarmigan ( Lagopus lagopus, L. muta) across the tundra of northern Alaska to determine whether forage requirements explain the distribution of herbivores in this ecosystem. In addition, we examined the potential for competition among these three shrub-dependent species. We recorded shrub characteristics and browsing levels at 59 sites along a 568 km riparian transect spanning from the Brooks Range to the Arctic Coast. Mean shrub height was positively correlated with browsing intensity for all three species ( r = 0.40-0.71). The minimum shrub height threshold for hare occurrence (≥87 cm, 95% CI: 67-94) was similar to that for moose (≥81 cm, 95% CI: 65-96), whereas ptarmigan were nearly ubiquitous (≥3 cm, lower 95% CI = 0). Diet overlap among herbivores was nearly complete, with all three species heavily browsing feltleaf willow ( Salix alaxensis). Our findings indicate that unlike moose and ptarmigan, forage availability does not appear to control the distribution of snowshoe hares in the Arctic. Resource competition may further affect distribution patterns within this guild as shrub cover continues to expand. [ABSTRACT FROM AUTHOR]

Some empirical and theoretical studies suggest that more mobile species are less at risk in human-altered landscapes, while others suggest the opposite., We propose three novel hypotheses to explain these contradictory findings: (i) extinction risk increases with increasing mobility when mobility is measured as emigration, but decreases with increasing mobility when mobility is measured as immigration; (ii) the most mobile species (whether measured by emigration or immigration) in unaltered landscapes are least mobile in human-altered landscapes, so the relationship between mobility and risk is opposite when mobility is measured in unaltered and altered landscapes; and (iii) the mobility-risk relationship is ∩-shaped; thus, the relationship is apparently positive when studied species have low-to-intermediate mobility, but negative when species have intermediate-to-high mobility. We also evaluate a fourth hypothesis that had been previously theorized: that some landscape structures drive evolution of dispersal characteristics that increase both mobility and risk, while others drive evolution of characteristics that increase mobility and decrease risk., To evaluate these four hypotheses, we created an individual-based, spatially explicit simulation model to simulate population dynamics, evolution of dispersal characteristics and species response to habitat loss., Our simulations supported the first and fourth hypotheses. Extinction risk increased with emigration rate but decreased with immigration rate. Species in landscapes with historically more abundant, less fragmented habitat and more frequent disturbance had increased risk and mobility during habitat loss, while species in landscapes with lower matrix quality had increased risk and decreased mobility., Synthesis. This is the first study to investigate why some studies find that more mobile species are less at risk in human-altered landscapes, while others find the opposite. Our results suggest that these contradictory relationships occur because of differences in how mobility is measured and differences in the historic structure of species' landscapes. Understanding how mobility and the historic landscape influence extinction risk can help us identify species of conservation concern. Our results suggest that we should focus on species with high emigration rates but low immigration rates, and those that evolved in landscapes with non-fragmented habitat and high-risk matrix. [ABSTRACT FROM AUTHOR]

Warming during the 20th century has changed the arctic landscape, including aspects of the hydrology, vegetation, permafrost, and glaciers, but effects on wildlife have been difficult to detect. The primary aim of this study is to examine the physical and biological processes contributing to the expanded riparian habitat and range of snowshoe hares (Lepus americanus) in northern Alaska. We explore linkages between components of the riparian ecosystem in Arctic Alaska since the 1960s, including seasonality of stream flow, air temperature, floodplain shrub habitat, and snowshoe hare distributions. Our analyses show that the peak discharge during spring snowmelt has occurred on average 3.4 days per decade earlier over the last 30 years and has contributed to a longer growing season in floodplain ecosystems. We use empirical correlations between cumulative summer warmth and riparian shrub height to reconstruct annual changes in shrub height from the 1960s to the present. The effects of longer and warmer growing seasons are estimated to have stimulated a 78% increase in the height of riparian shrubs. Earlier spring discharge and the estimated increase in riparian shrub height are consistent with observed riparian shrub expansion in the region. Our browsing measurements show that snowshoe hares require a mean riparian shrub height of at least 1.24-1.36 m, a threshold which our hindcasting indicates was met between 1964 and 1989. This generally coincides with observational evidence we present suggesting that snowshoe hares became established in 1977 or 1978. Warming and expanded shrub habitat is the most plausible reason for recent snowshoe hare establishment in Arctic Alaska. The establishment of snowshoe hares and other shrub herbivores in the Arctic in response to increasing shrub habitat is a contrasting terrestrial counterpart to the decline in marine mammals reliant on decreasing sea ice. [ABSTRACT FROM AUTHOR]

A citizen science project was developed to encourage homeowners and others to build and monitor artificial nesting habitats for solitary bees and wasps. Social media applications were used to recruit participants and provide forums for social discussion and participation. Between April 2012 and July 2014, 268 individuals and 19 groups registered for the Native Buzz project at www.ufnativebuzz.com for a total combined membership of 655 participants. Participants were located in 30 counties in Florida as well as 38 other states and 10 additional countries. Participants had designed, built and monitored 68 artificial nest sites by July 2014. During the two-year study period, the sites collectively contained over 10,657 potential nests constructed from a variety of materials and established within a variety of ecosystems. Comments solicited from participants were used to identify future needs, motivating factors and challenges associated with implementing an ''insect-oriented'' citizen science project. Results of this study indicate that technology-based citizen science projects of this type can effectively recruit non-scientist citizens to create artificial nesting habitats for solitary bees and wasps and provide a useful platform for helping entomological researchers collect solitary bee and wasp nesting data from a large geographic range via data provided by volunteer citizen scientists. [ABSTRACT FROM AUTHOR]

Habitat fragmentation in aquatic systems has led to widespread isolation of stream fishes. Metapopulation theory predicts that persistence is directly related to local patch size and its characteristics, but because these relationships tend to be taxon-specific, empirical data are important. We assembled 246 observations of occurrence of westslope cutthroat trout ( WCT), a taxon of concern in the western U.S. and Canada, in stream networks isolated for up to 100 years (median 40 years) above human-made barriers, mostly culverts, at road crossings within U.S. National Forests. We used logistic regression to analyse how WCT occurrence varied with patch size, isolation time and stream-level covariates. Occurrence was positively related to stream length and habitat quality within the isolated stream network and negatively related to elevation and channel gradient. Unexpectedly, the probability of occurrence was not related to how long a habitat patch had been isolated. At the median elevation (1354 m) and channel gradient (14%), and where habitat quality was poor, WCT were likely to occur (probability >0.5) if an isolated stream network was at least 1.7 km. If habitat quality was high, about 0.2 km of habitat produced the same probability. Although there are important limitations, this analysis provides the first empirical estimate for how patch size and patch-level characteristics influence persistence of WCT in isolated stream networks. [ABSTRACT FROM AUTHOR]

Theoretical models predict strong influences of habitat loss and fragmentation on species distributions and demography, but empirical studies have shown relatively inconsistent support across species and systems. We argue that species' responses to landscape-scale habitat loss and fragmentation are likely to appear less idiosyncratic if it is recognized that species perceive the same landscapes in different ways. We present a new quantitative approach that uses species distribution models (SDMs) to measure landscapes (e.g. patch size, isolation, matrix amount) from the perspective of individual species. First, we briefly summarize the few efforts to date demonstrating that once differences in habitat distributions are controlled, consistencies in species' responses to landscape structure emerge. Second, we present a detailed example providing step-by-step methods for application of a species-centered approach using freely available land-cover data and recent statistical modeling approaches. Third, we discuss pitfalls in current applications of the approach and recommend avenues for future developments. We conclude that the species-centered approach offers considerable promise as a means to test whether sensitivity to habitat loss and fragmentation is mediated by phylogenetic, ecological, and life-history traits. Cross-species generalities in responses to habitat loss and fragmentation will be challenging to uncover unless landscape mosaics are defined using models that reflect differing species-specific distributions, functional connectivity, and domains of scale. The emergence of such generalities would not only enhance scientific understanding of biotic processes driving fragmentation effects, but would allow managers to estimate species sensitivities in new regions. [ABSTRACT FROM AUTHOR]

We tested the hypotheses that species with greater mobility and/or higher reproductive rates are less sensitive to habitat loss than species with lower mobility and/or reproductive rates by conducting a meta-analysis of wetland vertebrate responses to wetland habitat loss. We combined data from 90 studies conducted worldwide that quantified the relationship between wetland amount in a landscape and population abundance of at least one wetland species to determine if mobility (indexed as home range size and body length) and annual reproductive rate influence species responses to wetland loss. When analyzed across all taxa, animals with higher reproductive rates were less sensitive to wetland loss. Surprisingly, we did not find an effect of mobility on response to wetland loss. Overall, wetland mammals and birds were more sensitive to wetland loss than were reptiles and amphibians. Our results suggest that dispersal between habitat patches is less important than species’ reproductive rates for population persistence in fragmented landscapes. This implies that immigration and colonization rate is most strongly related to reproduction, which determines the total number of potential colonists. [ABSTRACT FROM AUTHOR]

Intentional release of wild-caught individuals has been widely used to establish new populations of the commercially valuable but threatened reef gastropodTrochus niloticusin oceanic islands. Is this also a viable strategy to enhance depleted populations of this species and other marine invertebrates? We monitored growth and survival of 765 translocated individuals and 486 in their original habitat for 5–9 months. Individuals translocated to a severely overexploited reef (mainland Palawan) grew 2–3 times faster than those at Tubbataha Reefs Natural Park, Phillipines. Despite variations in growth between the three sites, survival probabilities were consistently high, ranging between 0.77 and 0.92. So translocation is feasible, and sites at which a species has previously been found are likely to be suitable for their growth and survival. If site management can control over-fishing, this approach is likely to be a valuable tool for enhancing field populations of a large invertebrates likeTrochusthat have a short lived planktonic larva. [ABSTRACT FROM PUBLISHER]

Copyright of Canadian Journal of Fisheries & Aquatic Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses the research program on the Willow Flycatcher Empidonax traillii to determine its population demographics, and the impact of weather events and the distribution of regional-scale meadow and vegetative structure on its nesting success. The study found that the length of the breeding season of the Willow Flycatcher was reduced by the occurrence of late-spring storms and low temperatures at the start of breeding season, affecting its ability to renest. It showed nest survival to be better predicted by nest age, and an increase in nest survival in large meadows with over-nest vegetation concealment. The authors suggest that the differences in the length of breeding season and the quality of habitat in meadows have contributed to decreasing its reproductive success.

Communities in fragmented landscapes are often assumed to be structured by species extinction due to habitat loss, which has led to extensive use of the species-area relationship (SAR) in fragmentation studies. However, the use of the SAR presupposes that habitat loss leads species to extinction but does not allow for extinction to be offset by colonization of disturbed-habitat specialists. Moreover, the use of SAR assumes that species richness is a good proxy of community changes in fragmented landscapes. Here, we assessed how communities dwelling in fragmented landscapes are influenced by habitat loss at multiple scales; then we estimated the ability of models ruled by SAR and by species turnover in successfully predicting changes in community composition, and asked whether species richness is indeed an informative community metric. To address these issues, we used a data set consisting of 140 bird species sampled in 65 patches, from six landscapes with different proportions of forest cover in the Atlantic Forest of Brazil. We compared empirical patterns against simulations of over 8 million communities structured by different magnitudes of the power-law SAR and with species-specific rules to assign species to sites. Empirical results showed that, while bird community composition was strongly influenced by habitat loss at the patch and landscape scale, species richness remained largely unaffected. Modeling results revealed that the compositional changes observed in the Atlantic Forest bird metacommunity were only matched by models with either unrealistic magnitudes of the SAR or by models ruled by species turnover, akin to what would be observed along natural gradients. We show that, in the presence of such compositional turnover, species richness is poorly correlated with species extinction, and z values of the SAR strongly underestimate the effects of habitat loss. We suggest that the observed compositional changes are driven by each species reaching its individual extinction threshold: either a threshold of forest cover for species that disappear with habitat loss, or of matrix cover for species that benefit from habitat loss. [ABSTRACT FROM AUTHOR]

The spatial extent at which landscape structure best predicts population response, called the scale of effect, varies across species. An ability to predict the scale of effect of a landscape using species traits would make landscape study design more efficient and would enable landscape managers to plan at the appropriate scale. We used an individual based simulation model to predict how species traits influence the scale of effect. Specifically, we tested the effects of dispersal distance, reproductive rate, and informed movement behavior on the radius at which percent habitat cover best predicts population abundance in a focal area. Scale of effect for species with random movement behavior was compared to scale of effect for species with three (cumulative) levels of information use during dispersal: habitat based settlement, conspecific density based settlement, and gap-avoidance during movement. Consistent with a common belief among researchers, dispersal distance had a strong, positive influence on scale of effect. A general guideline for empiricists is to expect the radius of a landscape to be 4-9 times the median dispersal distance or 0.3-0.5 times the maximum dispersal distance of a species. Informed dispersal led to greater increases in population size than did increased reproductive rate. Similarly, informed dispersal led to more strongly decreased scales of effect than did reproductive rate. Most notably, gap-avoidance resulted in scales that were 0.2-0.5 times those of non-avoidant species. This is the first study to generate testable hypotheses concerning the mechanisms underlying the scale at which populations respond to the landscape. [ABSTRACT FROM AUTHOR]

Stormwater retention ponds in urbanizing catchments are constructed to collect and treat runoff from impervious surfaces. Amphibians often inhabit retention ponds, which may partly offset the loss of natural wetlands resulting from urbanization. We investigated the use of retention ponds by frogs in a rapidly-urbanizing region of south-eastern Australia to (1) determine the habitat attributes associated with individual species, and (2) recommend specific wetland design criteria to enhance populations of frog species in the region and in other urbanizing areas throughout their distribution. We detected nine species of frogs during calling surveys at 30 retention pond sites in Greater Melbourne, 2008-2010. There were contrasting differences in habitat associations among five species for which we produced regression models of abundance or occurrence. The mean abundance of Crinia signifera increased with site area, whereas Limnodynastes dumerilii was associated with smaller sites. The occurrence of L. dumerilii was positively associated with waterbody shore depth, whereas L. peronii and L. tasmaniensis were associated with shallow shores. Two species were positively associated with time since construction or since dredging of a site, whereas the occurrence of L. dumerilii decreased with site age. Aquatic vegetation at a site was important for the occurrence of L. peronii and Litoria ewingii. There was evidence for a positive effect of aquatic connectivity on the occurrence of Limnodynastes peronii, which emphasizes the importance of riparian corridors in urban settings. These results highlight the contrasting differences in habitat associations among species in the region. We recommend that retention ponds in our region and elsewhere be constructed or enhanced to include specific habitat attributes that were found to be associated with different amphibian species. We recommend long-term monitoring at sites to determine whether retention ponds augment existing frog populations or contribute to declines. [ABSTRACT FROM AUTHOR]

Monitoring the populations of badgers and red foxes may help us to manage these predator species as a matter of wildlife conservation and regulation. To fit the needs of a monitoring programme, the most practicable method has to be selected. Hunting bag statistics deliver large but inaccurate data amounts with low effort. Indirect and also often direct counts might deliver only presence-absence data with high effort. Direct counts with high accuracy are very costly. Den mapping by volunteer local hunters can deliver reliable data on density and additional biological variables while being feasible and cost effective. Within reference areas all over Germany, fox and badger dens and litters were recorded, and spring and summer densities estimated as well as potential annual population increases were calculated for 2003-2007. Habitat preferences for breeding dens were also analysed. Additionally, in 2006, the distribution of badgers was surveyed by a nationwide questionnaire. Fox and badger are distributed all over Germany with some small gaps and regionally differing densities. During the monitoring period, fox and badger densities and reproduction stayed stable, at a high level corresponding to hunting bags. However, densities varied between geographical regions, with lower densities in the sparsely wooded lowland regions. A preference for forest and habitats offering shelter was clear for breeding setts and dens. Badgers especially preferred setts of natural origin. [ABSTRACT FROM AUTHOR]

Songbird presence is often associated with the area of suitable habitat in the surrounding landscape. However, the size of landscape for which this association is maximized is generally unknown, likely to vary among species, and may affect our ability to incorporate songbirds in landscape management. We measured the occurrence and the persistence of forest songbirds in relation to the amount of habitat measured at several scales: local (100, 200 m radius), neighborhood (400, 800 m), landscape (1.6, 3.2, 6.4 km) and regional (12-24 km), based on data from Ontario's Forest Bird Monitoring Program (1987-2005). Songbird occurrence was obtained from point count sites distributed across southern Ontario and each revisited in multiple years (mean=5.8 yr). Presence of each species at a site was associated with forest habitat area measures that account for differences in preferred forest cover types among species. Area of coniferous, deciduous and mixed forest was derived from Landsat TM imagery. Thirty-two of the 35 species studied were area-sensitive, and area-sensitivity was apparent for 13-25 species at each spatial scale. For 24 species, the strength of area-sensitivity varied with scale, suggesting the importance of local, neighborhood, landscape and regional habitat for 3, 5, 5, and 11 species respectively. As a result, the list of the five most area-sensitive species varied depending on the scale at which habitat was described. We conclude that area-sensitivity can occur at a broader set of scales than generally assumed, and is most pronounced at the regional scale. We suggest that a broad set of scales should be examined before taking conservation decisions based on avian area-sensitivity. [ABSTRACT FROM AUTHOR]

Within forests susceptible to wildfire and insect infestations, land managers need to balance dead tree removal and habitat requirements for wildlife species associated with snags. We used Mahalanobis distance methods to develop predictive models of white-headed woodpecker (Picoides albolarvatus) nesting habitat in postfire ponderosa pine (Pinus ponderosa)-dominated landscapes on the Fremont-Winema National Forests in south central Oregon, USA. The 1-km radius (314 ha) surrounding 45 nest sites was open-canopied before fire and a mosaic of burn severities after wildfire. The 1-ha surrounding nests of white-headed woodpeckers had fewer live trees per hectare and more decayed and larger diameter snags than at non-nest sites. The leading cause of nest failure seemed to be predation. Habitat and abiotic features were not associated with nest survival. High daily survival rates and little variation within habitat features among nest locations suggest white-headed woodpeckers were consistently selecting high suitability habitats. Management activities that open the forest canopy and create conditions conducive to a mosaic burn pattern will probably provide suitable white-headed woodpecker nesting habitat after wildfire. When making postfire salvage logging decisions, we suggest that retention of larger, more decayed snags will provide nesting habitat in recently burned forests. [ABSTRACT FROM AUTHOR]

Livestock predation and associated human-carnivore conflicts are increasing worldwide and require the development of methods and concepts for risk assessment and conflict management. Here we use knowledge on habitat preference and distribution of pumas and provide a first assessment of the spatial risk of livestock to puma depredation in Patagonian ranches, Argentina. In an initial step, we developed a rule-based habitat model in a Geographic Information System (GIS) to predict the distribution of puma habitat at a regional scale in Patagonia. We then used empirically derived puma occurrence records from Patagonian ranches 1) to test our regional habitat predictions, and 2) to evaluate if paddock characteristics (vegetation cover, topography, and distance to roads) contribute to explain puma occurrences within ranches. Finally, we simulated three livestock management scenarios differing in their spatial and seasonal allocation of livestock to paddocks, and compared the likelihood of livestock exposure to pumas among scenarios. At a regional scale, 22% of the study region was predicted to be suitable for puma home ranges. The greatest uncertainty in these predictions resulted from assumptions on woody vegetation cover requirements at the home range scale. Within ranches, puma occurrences were positively associated with paddock topography, woody vegetation cover on paddocks, and proximity to predicted regional puma habitat. Comparing the risk of predation by puma among simulated livestock management scenarios implied that rotating livestock during seasons may help to reduce the likelihood of livestock exposure to pumas. Our results show the usefulness of rule-based habitat models for describing broad-scale carnivore distributions and for aiding risk assessments to mitigate conflicts between predators and human activities. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim To investigate the relationships between bird species richness derived from the North American Breeding Bird Survey and estimates of the average, minimum, and the seasonal variation in canopy light absorbance (the fraction of absorbed photosynthetically active radiation, fPAR) derived from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS). Location Continental USA. Methods We describe and apply a ‘dynamic habitat index’ (DHI), which incorporates three components based on monthly measures of canopy light absorbance through the year. The three components are the annual sum, the minimum, and the seasonal variation in monthly fPAR, acquired at a spatial resolution of 1 km, over a 6-year period (2000–05). The capacity of these three DHI components to predict bird species richness across 84 defined ecoregions was assessed using regression models. Results Total bird species richness showed the highest correlation with the composite DHI [ R2 = 0.88, P < 0.001, standard error of estimate (SE) = 8 species], followed by canopy nesters ( R2 = 0.79, P < 0.001, SE = 3 species) and grassland species ( R2 = 0.74, P < 0.001, SE = 1 species). Overall, the seasonal variation in fPAR, compared with the annual average fPAR, and its spatial variation across the landscape, were the components that accounted for most ( R2 = 0.55–0.88) of the observed variation in bird species richness. Main conclusions The strong relationship between the DHI and observed avian biodiversity suggests that seasonal and interannual variation in remotely sensed fPAR can provide an effective tool for predicting patterns of avian species richness at regional and broader scales, across the conterminous USA. [ABSTRACT FROM AUTHOR]

The loss of wetlands and semi-natural grasslands throughout much of Europe has led to a historic decline of species associated with these habitats. The reinstatement of these habitats, however, requires spatially explicit predictions of the most suitable sites for restoration, to maximize the ecological benefit per unit effort. One species that demonstrates such declines is the white stork Ciconia ciconia, and the restoration of habitat for this flagship species is likely to benefit a suite of other wetland and grassland biota. Storks are also being reintroduced into southern Sweden and elsewhere, and the a priori identification of suitable sites for reintroduction will greatly improve the success of such programmes. Here a simple predictive habitat-use model was developed, where only a small but reliable presence-only dataset was available. The model is based on the extent and relative soil moisture of semi-natural pastures, the extent of wetlands and the extent of hayfields in southern Sweden. Here the model was used to predict the current extent of stork habitat that is suitable for successful breeding, and the extent of habitat that would become suitable with moderate habitat restoration. The habitat model identifies all 10 occupied nesting sites where breeding is currently successful. It also identifies ∼300 km2 of habitat that is predicted to be suitable stork habitat, but that is presently unused; these sites were identified as potential areas for stork reintroduction. The model also identifies over 100 areas where moderate habitat restoration is predicted to have a disproportionate effect (relative to the restoration effort) on the area of suitable habitat for storks; these sites were identified as priorities for habitat restoration. By identifying areas for reintroduction and restoration, such habitat suitability models have the potential to maximize the effectiveness of such conservation programmes. [ABSTRACT FROM AUTHOR]

The impact of the landscape matrix on patterns of animal movement and population dynamics has been widely recognized by ecologists. However, few tools are available to model the matrix's influence on the length, relative quality, and redundancy of dispersal routes connecting habitat patches. Many GIS software packages can use land use/land cover maps to identify the route of least resistance between two points—the least-cost path. The limitation of this type of analysis is that only a single path is identified, even though alternative paths with comparable costs might exist. In this paper, we implemented two graph theory methods that extend the least-cost path approach: the Conditional Minimum Transit Cost (CMTC) tool and the Multiple Shortest Paths (MSPs) tool. Both methods enable the visualization of multiple dispersal routes that, together, are assumed to form a corridor. We show that corridors containing alternative dispersal routes emerge when favorable habitat is randomly distributed in space. As clusters of favorable habitat start forming, corridors become less redundant and dispersal bottlenecks become visible. Our approach is illustrated using data from a real landscape in the Brazilian Atlantic forest. We explored the effect of small, localized disturbance on dispersal routes linking conservation units. Simulated habitat destruction caused the appearance of alternative dispersal routes, or caused existing corridors to become narrower. These changes were observed even in the absence of significant differences in the length or cost of least-cost paths. Last, we discuss applications to animal movement studies and conservation initiatives. [ABSTRACT FROM AUTHOR]

This study presents a graph-theoretical modelling approach using daily movements and habitat demands of different target bird species in an urban context to assess: 1) habitable land cover types, 2) threshold distances between patches of habitat, 3) the required minimum accessible habitat areas and 4) the effects of barriers and stepping stones. The modelling approach is tested using empirical data from field surveys in the urban area of Stockholm, Sweden. The results show that groups of small habitat patches can house the same species as larger contiguous patches as long as they are perceived as functionally connected by the inhabitant organisms. Furthermore, we found that binary habitat/non-habitat representations of the landscape could roughly explain the variation in species occurrence, as long as habitat was properly defined. However, the explanatory power of the landscape models increased when features of matrix heterogeneity such as stepping stones and barriers were accounted for. Synthesis and application: in a world where forest ecosystems are becoming increasingly fragmented there is an urgent need to find comprehensive and scientifically relevant methods for managing and planning ecosystems. This study shows that: 1) groups of well placed small habitat patches can, together, be sufficient to attract birds in intensively developed areas, 2) the presented modelling approach can help identify such groups of patches, 3) matrix heterogeneity should preferably be accounted for, and 4) proper assessments of habitable land cover types are important. Finally, we argue that the modelling approach applied here may substantially improve landscape management and planning at scales ranging from whole landscapes down to neighbourhoods. [ABSTRACT FROM AUTHOR]

1. The severe and early destruction and fragmentation of woodland habitats due to human activities is thought to have been a leading factor in the extirpation from Britain of several large, forest-dependent mammal species, such as the Eurasian lynx Lynx lynx. However, during the 20th century, Scotland in particular has experienced rapid, large-scale reafforestation. In order to assess if this reafforestation has been sufficient to permit the potential restoration of extirpated forest mammal species with large spatial requirements, a Geographical Information System (GIS) analysis of potential habitat of one species, the Eurasian lynx, was performed for the Scottish mainland. 2. A rule-based analysis, incorporating data and expert opinion from Switzerland, an environmentally similar area where lynx now occur, was used to identify patches of suitable lynx habitat in Scotland. A connectivity analysis was used to investigate whether and how these patches are connected to form larger interconnected networks of potential lynx habitat that would allow lynx to sufficiently interact with one another to form a single interbreeding population. 3. Scotland has over 20 000 km2 of suitable lynx habitat split into two main networks of interconnected patches: the Highlands ( c. 15 000 km2) and the Southern Uplands ( c. 5000 km2). A further 800 km2 of potential habitat, contiguous with the Southern Uplands lynx habitat network, lies across the border in England. Although connectivity between the Highlands and Southern Uplands networks is currently weak, the implementation of measures to mitigate the barrier effects of busy roads in central Scotland could facilitate the movement of lynx between the two areas. 4. Based on the availability of prey resources, Scotland could support around 400 adult and subadult lynx in the Highlands and around 50 in the Southern Uplands. A Scottish population of this size would be the fourth largest lynx population in Europe considering current population estimates. [ABSTRACT FROM AUTHOR]

The article discusses a study on the estimation of required habitat size that is efficient for fish conservation in streams. It describes a procedure that would estimate viable population size and the area of habitat needed to support an endangered stream fish population. It evaluates the population fates with stochastic demography and random variation using Monte Carlo Simulations. It uses the data for Rio Grande Cutthroat trout or the Oncorhynchus clarkii virginalis. It mentions that there is an occurrence of minimum viable population size at the highest survival rate of young of year and no population-wide year class failures.

1. An important target for conservation planning is the minimum amount of habitat needed in a landscape to ensure the persistence of a species. Appropriate targets can be determined by identifying thresholds in the amount of habitat, below which persistence, abundance or occupancy declines rapidly. Although some studies have identified habitat thresholds, we currently have little understanding of the extent to which thresholds vary spatially. This is important for establishing whether we can apply the same planning targets across broad geographical regions. 2. We quantified habitat–occupancy relationships for the koala Phascolarctos cinereus (Goldfuss) in three study regions that span much of its geographical range. Standard and piecewise (broken-stick/segmented) logistic regression were used to model linear and threshold habitat–occupancy relationships. We then used an information-theoretic approach to test: (1) whether habitat–occupancy relationships were described better by threshold or linear models and (2) where threshold models were better, whether, and to what extent, threshold points varied among study regions. 3. There was substantially greater support for the threshold than the linear models across a range of habitat qualities and landscape extents. The threshold models generally predicted a rapid decline in occupancy below the threshold points. 4. Estimated threshold points varied, sometimes substantially, among study regions. This may relate to cross-regional differences in habitat quality, demographic rates, and land-use patterns. The role of habitat fragmentation is unclear. 5. Synthesis and applications. Variation in threshold points among study regions suggests that we should be wary of using thresholds derived in one region for setting conservation planning targets in another. Rather, we should aim to set specific targets for individual locations (and species), while acknowledging the inherent uncertainties in these targets. This has implications for our ability to make general conservation prescriptions for widely distributed species. Future research should aim to develop generic models capable of predicting threshold responses across different landscapes and life-history characteristics. [ABSTRACT FROM AUTHOR]

Lahontan cutthroat trout, Oncorhynchus clarki henshawi, are currently limited in their distribution to a patchwork of small isolated populations, the result of habitat degradation and natural variation in landscape and in-stream conditions. The objectives of this study were to determine if landscape topography influences trout distribution, and if water temperatures control this response. The work was carried out in a sub-basin of the Quinn River system, McDermitt Creek, which drains the sagebrush desert of southeastern Oregon and northern Nevada. Headwater tributaries of this creek consist of alternating canyon-confined and valley bounded reaches. Trout within these systems are challenged by low discharge and high temperatures during the summer, and anchor ice during the winter. Contiguous whole stream surveys were used to look at trout distribution during the summer of 2003 and spring and fall of 2004. Our results suggested that topography can affect trout distribution. Trout numbers were highest in areas with greater numbers of nick-points (the transition zones between less confined and more confined valley segments) and greater valley confinement. Additionally, in the downstream portion of our headwater reaches, more trout were found in nick-points than expected based on the availability of this habitat type. Our data suggest that hyporheic inputs may be high in such areas, thus providing trout with shelter from warm water in the summer, anchor ice in the winter, and shallow stream depths during all seasons. Spatial occurrence of these areas of refugia can be taken into consideration when planning land use activities and restoration efforts. Further research is required to confirm that topography can affect the distribution of Lahontan cutthroat trout in other systems, and to better understand the mechanisms behind these patterns. [ABSTRACT FROM AUTHOR]

To maximize success, reintroduction programs generally select predator-free release areas having high habitat quality. Past studies provide little insight into recovery efforts where multiple, potentially novel, mortality hazards occur. The ability of translocated animals to cope with novel environments can be affected by both pre- and postrelease experiences with habitat and mortality risks. We experimentally released elk (Cervus elaphus) having different background experiences into an area where predators and hunters were prevalent and habitat quality varied. Using a competing risks approach, we predicted the postrelease survival of individuals and their fidelity to release areas as a function of animal source and postrelease encounters with forage resources and areas used by wolves (Canis lupus) or humans. Mortality patterns were consistent with prerelease exposure to mortality risks but not habitat differences among source areas. Wolf predation, poaching, and legal Native hunting were equivalent in magnitude and accounted for the majority of elk mortalities. Familiarity with either wolves or hunters prior to release yielded first-year survival rates 1.9-2.2 times greater than observed for animals naïve to both risks. These 2 primary sources of mortality traded off temporally as well as spatially given the proximity of roads, which wolves avoided. The prevalence of forage resources in release areas increased fidelity to release sites but coincided with higher mortality risk during the critical first year, potentially setting an ecological trap for animals naïve to local risks. Translocated individuals largely mediated their respective vulnerabilities over time, showing second-year survival rates equivalent to resident elk. In addition to using source populations that are able to adjust to mortality risks in release areas, spatial and temporal variation in mortality risks might be exploited when planning releases to increase the success of translocations into risky landscapes. [ABSTRACT FROM AUTHOR]

Habitat fragmentation edge effects on riverine fish could have implications for stream fish populations and their management. We examined effects of forest fragmentation on banded kokopu and longfin eels in New Zealand. Banded kokopu prefer small shaded streams with bouldery substrates and instream cover, whereas longfin eels are found in a variety of habitats. We hypothesized that the densities of banded kokopu would be higher in forested than grassland streams, and the densities would be lower around forest margins. We sampled pools in streams flowing from native podocarp/broad-leaf forests into grassland using Gee–Minnow traps. Pools were sampled longitudinally on each stream from >50 m into the forest to >50 m downstream from the forest margin in open grassland. Banded kokopu densities were higher in interior habitat ?50 m into forests than in grassland streams. Fish caught in grassland pools were smaller than in forested pools. Longfin eels were caught in all streams, but numbers and sizes were similar in habitats; thus not likely to generate the pattern observed for banded kokopu. We found that terrestrial habitat fragmentation can impact stream fish populations by decreasing their occupancy of habitats in the vicinity of the boundary between different terrestrial habitats. [ABSTRACT FROM AUTHOR]

Quist MC, Rahel FJ, Hubert WA. Hierarchical faunal filters: an approach to assessing effects of habitat and nonnative species on native fishes.Ecology of Freshwater Fish 2004.© Blackwell Munksgaard, 2004Understanding factors related to the occurrence of species across multiple spatial and temporal scales is critical to the conservation and management of native fishes, especially for those species at the edge of their natural distribution. We used the concept of hierarchical faunal filters to provide a framework for investigating the influence of habitat characteristics and nonnative piscivores on the occurrence of 10 native fishes in streams of the North Platte River watershed in Wyoming. Three faunal filters were developed for each species: (i) large-scale biogeographic, (ii) local abiotic, and (iii) biotic. The large-scale biogeographic filter, composed of elevation and stream-size thresholds, was used to determine the boundaries within which each species might be expected to occur. Then, a local abiotic filter (i.e., habitat associations), developed using binary logistic-regression analysis, estimated the probability of occurrence of each species from features such as maximum depth, substrate composition, submergent aquatic vegetation, woody debris, and channel morphology (e.g., amount of pool habitat). Lastly, a biotic faunal filter was developed using binary logistic regression to estimate the probability of occurrence of each species relative to the abundance of nonnative piscivores in a reach. Conceptualising fish assemblages within a framework of hierarchical faunal filters is simple and logical, helps direct conservation and management activities, and provides important information on the ecology of fishes in the western Great Plains of North America. [ABSTRACT FROM AUTHOR]