Effects of roads on landscape structure within nested ecological units of the Northern Great Lakes Region, USA

Road development is a primary mechanism of fragmentation in the northern Great Lakes Region, removing original land cover, creating edge habitat, altering landscape structure and function, and increasing access for humans. We examined road density, landscape structure, and edge habitat created by roads for eight land cover types at two ecological extents within a 78,752 km² landscape. Road density ranged from 0.16 to 2.07 km/km² within land type associations. Between 5 and 60% of a land cover type was affected by roads, depending on the assumed depth-of-edge influence (DEI). Roads increased number of patches and patch density, and decreased mean patch size and largest patch index. Changes in patch size coefficient of variation and measures of patch shape complexity depended on ecological level (i.e. scale) and land cover class. Limited additional change in landscape metrics occurred as road DEI was increased from 20 to 300 m. Land cover type occurred in buffers at the same percentages as in the landscape as a whole. At finer extents, areas with greatest road densities did not always parallel those with greatest changes in landscape structure. Interactions of scale and variation in the distribution of roads across the region emphasize the importance of examining landscape metrics and road impacts within specific cover types and at appropriate, or multiple, scales. Although this region is densely forested, the fragmentation effects of roads are pervasive, significantly altering landscape structure within multiple forest cover classes and at differing ecological extents.     

The efficacy of small-scale conservation efforts, as assessed on Australian golf courses

Habitat remnants on urban green-space areas (i.e. parks, gardens and golf courses) sometimes provide refuge to urban-avoiding wildlife, leading some to suggest these areas may play a role in wildlife conservation if they are appropriately designed and managed. The high densities observed on some green-space areas may however be attributed to external influences. Localised efforts to enhance the habitat value of urban green-space areas may therefore have little more than a cosmetic effect. This study investigated environmental factors influencing bird, reptile, mammal and amphibian diversity on Australian golf courses to assess the efficacy of small-scale conservation efforts. Abundance and species richness did not simply reflect local habitat qualities but were instead, partly determined by the nature of the surrounding landscape (i.e. the area of adjacent built land, native vegetation and the number of connecting streams). Vertebrate abundance and species richness were however, also associated with on-site habitat characteristics, increasing with the area of native vegetation (all vertebrates), foliage height diversity and native grass cover (birds), tree density, native grass cover and the number of hollows (mammals), woody debris, patch width and canopy cover (reptiles), waterbody heterogeneity and aquatic vegetation complexity (frogs). Localised conservation efforts on small land types can benefit urban-avoiding wildlife. Urban green-space areas can provide refuge to urban-avoiding vertebrates provided combined efforts are made at patch (management), local (design) and landscape (planning) scales.     

Human-mediated shifts in animal habitat use: Sequential changes in pronghorn use of a natural gas field in Greater Yellowstone

To manage America’s 991,479 km² (245 million acres) of public BLM lands for such mixed uses as natural resource extraction, wildlife, and recreation requires knowledge about effects of habitat alterations. Two of North America’s largest natural gas fields occur in the southern region of the Greater Yellowstone Ecosystem (Wyoming), an area that contains >100,000 wintering ungulates. During a 5-year period (2005–2009), we concentrated on patterns of habitat selection of pronghorn (Antilocapra americana) to understand how winter weather and increasing habitat loss due to gas field development impact habitat selection. Since this population is held below a food ceiling (i.e., carrying capacity) by human harvest, we expected few habitat constraints on animal movements – hence we examined fine-scale habitat use in relationship to progressive energy footprints. We used mixed-effects resource selection function models on 125 GPS-collared female pronghorn, and analyzed a comprehensive set of factors that included habitat (e.g., slope, plant cover type) and variables examining the impact of gas field infrastructure and human activity (e.g., distance to nearest road and well pad, amount of habitat loss due to conversion to a road or well pad) inside gas fields. Our RSF models demonstrate: (1) a fivefold sequential decrease in habitat patches predicted to be of high use and (2) sequential fine-scale abandonment by pronghorn of areas with the greatest habitat loss and greatest industrial footprint. The ability to detect behavioral impacts may be a better sentinel and earlier warning for burgeoning impacts of resource extraction on wildlife populations than studies focused solely on demography. Nevertheless disentangling cause and effect through the use of behavior warrants further investigation.     

Difference in spatiotemporal patterns of wildlife road-crossings and wildlife-vehicle collisions

Human–wildlife conflicts like wildlife–vehicle collisions pose major challenges for the management and conservation of mobile wildlife in human-dominated landscapes, particularly when large species are involved. Mitigation measures to reduce risk of collisions may be based on information given by wildlife movement and collision data. To test whether movement and collision data indicate different spatiotemporal risk zones, we predicted year-around probabilities of road-crossings of GPS-marked female moose (Alces alces) (n = 102), and compared them with spatiotemporal patterns of police recorded moose-vehicle collisions (n = 1158). Probability of moose road-crossings peaked in May, June, and between mid November and the beginning of January, i.e. during moose migration. Moose-vehicle collisions were more likely during autumn and winter. Comparing environmental attributes of crossing and collision sites showed significant differences. The likelihood of collisions increased with the abundance of human-modified areas and higher allowed speed, and was lower on forest roads. We found that animal movement data alone are insufficient to predict collision risk zones, while analyses of collision data alone overestimate the collision risk in certain habitats. Our findings suggest that higher collision risk is largely due to low light and poor road surface conditions rather than to more animal road-crossings. This suggests that efforts to reduce wildlife collisions should focus on driver attitudes and road conditions rather than animal movement, and any efforts to model the collision risk will require actual collision data, and not just movement data.     

Testing the importance of spatial configuration of winter habitat for woodland caribou: An application of graph theory

Conservation of remaining woodland caribou (Rangifer tarandus caribou) populations requires land management strategies that not only maintain caribou habitat, but also favour habitat connectivity. This study presents and field tests graph theory-based measures of landscape connectivity, and demonstrate an association between the distribution of woodland caribou and well-connected winter habitat. Cost values for the intervening land cover types were determined based on the probability of selection relative to high-quality winter habitat. Habitat connectivity was then represented by linking high-quality habitat patches along least-cost paths through this parameterized cost surface. A randomization procedure was used to assess the animal’s association with habitat connected at increasing distance thresholds to identify appropriate scales of response. A strong relationship was obtained between large clusters of high-quality winter habitat patches and winter GPS telemetry location points (November 1-March 15) from two woodland caribou herds in Manitoba, Canada. This relationship was stronger when only late winter location points (January 1-March 15) were used. Our results highlight the importance of accounting for the spatial configuration of habitat on the landscape and the intervening land cover types when assessing range quality for woodland caribou. They also provide support for the use of graph theory to assist in identifying core activity areas for woodland caribou and key linkages between these areas and other parts of the landscape.     

Building large-scale spatially explicit models to predict the distribution of suitable habitat patches for the Greater rhea (Rhea americana), a near-threatened species

We developed large-scale spatially explicit models to predict the distribution of suitable habitat patches for the Greater rhea (Rhea americana), a near-threatened species, in two areas of central Argentina with different land use: a grassland area (ca. 4943 km²) mainly devoted to cattle grazing and an agro-ecosystem area (ca. 4006 km²) mostly used for crop production. The models were developed using logistic regression and were based on current records of Greater rhea occurrence coupled with remote sensing data, including land cover and human presence variables. The habitat suitability maps generated were used to predict the suitable habitat patch structure for wild rhea populations in each area. Fifty-one percent of the total grassland area was suitable for the species, being represented by a single large patch that included 62% of the individual locations. In the agro-ecosystem, only 28% of the total area was suitable, which was distributed among four patches. Seventy percent of rhea observations were in suitable habitat, with all rheas grouped in the largest patch. Conservation efforts for preserving wild rhea populations should be focused on maintaining habitats similar to grasslands, which are less profitable for landowners at present. Consequently, the protection of the pampas grasslands, a key habitat for this species as well as for others with similar habitat requirements, will demand strong conservation actions through the reconciliation of interests between producers and conservationists, since the proportion of croplands is increasing.     

GIS-models work well, but are not enough: Habitat preferences of Lanius collurio at multiple levels and conservation implications

Species conservation largely depends on knowledge of habitat needs of target species. GIS-models are increasingly used to assess habitat preferences and distribution of target species, but their accuracy is constrained by availability of digital data layers. We developed a two-steps approach aiming at showing pros and cons of landscape (GIS)- and site-level habitat models, identifying key habitat factors for conservation of a threatened bird species, the red-backed shrike Lanius collurio. A spatially explicit GIS-model was generated using landscape variables, and a second model at site level was developed using fine-scale variables measured on the ground. The GIS-based model was then extrapolated to the entire region to obtain a map of distribution of suitable habitats. Positive associations between shrike occurrence and both hedgerow length and partial shrub cover were detected at both scales. Shrikes were also positively associated with grassland cover at landscape level and with partial cover of untilled herbaceous vegetation at the finer scale, and negatively affected by lucerne cover. The GIS-model led to an affordable map of predicted habitat suitability which should help conservationists to focus on different local priorities, but was unable to identify effects of untilled and lucerne cover. Site-level model gave fine details for habitat management, but its application elsewhere requires ground-measurements of factors. Combining the multiscale models could indicate more urgent actions at large scales (e.g. maintaining suitable habitats, or improving connectivity among isolated patches) and draw a detailed figure of the most suitable habitat for the species. Shrike occurrence was associated with a higher number of shrub and tree species: the indicator value of the species should ensure general benefits for biodiversity from dedicated management.     

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

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

Restoring habitat permeability to roaded landscapes with isometrically-scaled wildlife crossings

Globally, human activities impact from one-third to one-half of the earth’s land surface; a major component of development involves the construction of roads. In the US and Europe, road networks fragment normal animal movement patterns, reduce landscape permeability, and increase wildlife-vehicle collisions, often with serious wildlife population and human health consequences. Critically, the placement of wildlife crossing structures to restore landscape connectivity and reduce the number of wildlife-vehicle collisions has been a hit-or-miss proposition with little ecological underpinning, however recent important developments in allometric scaling laws can be used to guide their placement. In this paper, we used cluster analysis to develop domains of scale for mammalian species groups having similar vagility and developed metrics that reflect realistic species movement dynamics. We identified six home range area domains; three quarters of 102 species clustered in the three smallest domains. We used HR^0.5 to represent a daily movement metric; when individual species movements were plotted against road mile markers, 71.2% of 72 species found in North America were included at distances of ?1 mi. The placement of wildlife crossings based on the HR^0.5 metric, along with appropriate auxiliary mitigation, will re-establish landscape permeability by facilitating wildlife movement across the roaded landscape and significantly improve road safety by reducing wildlife vehicle collisions.     

Dynamic wildlife habitat models: Seasonal foods and mortality risk predict occupancy-abundance and habitat selection in grizzly bears

Most current wildlife habitat models, such as resource selection functions, typically assume a static environment, extrapolate poorly in space and time, and often lack linkages to population processes. We submit that more mechanistic habitat models that directly consider bottom-up resources affecting growth and reproduction (i.e., food) and top-down limitations affecting survival are needed to effectively predict habitat quality, especially in the presence of rapid environmental change. Here we present a general model for estimating potential habitat quality (relating to growth and reproduction) and realised habitat quality (accounting for survival) using basic knowledge of the species’ seasonal diet, predicted locations of food resource patches and regional patterns in mortality risk. We illustrate our model for a threatened population of grizzly bears in west-central Alberta. Bi-monthly potential habitat quality successfully predicted habitat selection by radio-collared grizzly bears, while multi-seasonal realised habitat quality predicted patterns in occupancy-abundance as measured from unique bears at hair-snag sites. Bottom-up resources therefore predicted patterns of habitat selection, while top-down processes (survival) were necessary to scale-up to population measures. We suggest that more direct measures of resources and environments that affect growth, reproduction and survival, as well as match the temporal scale of animal behaviour, be considered when developing wildlife habitat models.     

Habitat fragmentation in marine landscapes: relative effects of habitat cover and configuration on juvenile crab survival in California and North Carolina seagrass beds

Processes that dictate faunal abundance (e.g. predation) may be linked primarily to the configuration of habitat (e.g. patch size, patch isolation, proximity to edge) or simply to the amount of habitat (i.e. habitat cover) in marine and terrestrial systems. I asked whether juvenile crab survival in marine seagrass habitats is linked to habitat cover or to habitat configuration, and whether relationships between crab survival and habitat features were similar in two widely separated seagrass landscapes (Bodega Harbor, California and Back Sound, North Carolina, USA). I also evaluated the independent effects of seagrass structural complexity (shoot density and shoot biomass per unit area) and habitat fragmentation on crab survival. Juvenile red rock crabs (Cancer productus: 1+year class) were tethered in Bodega Harbor and juvenile blue crabs (Callinectes sapidus: 0+year class) were tethered in Back Sound. Seagrass cover in both landscapes ranged from <10 to 100% over 10×10 m areas. Crab survival was correlated with elements of landscape structure and structural complexity in both landscapes, but relationships between crab survival and specific habitat features differed between the two landscapes. In California, juvenile red rock crab survival was negatively correlated with seagrass cover and was positively correlated with seagrass shoot density, and was marginally (P=0.06) negatively correlated with seagrass shoot biomass. In North Carolina, juvenile blue crab survival was positively correlated with log₁₀ patch area and was negatively correlated with seagrass shoot biomass. The results indicate that (1) both seagrass cover and configuration may influence crab survival; (2) seagrass structural complexity influences crab survival independently of landscape structure; (3) the relative influence of cover, configuration and structural complexity on survival likely differ among seagrass landscapes; and (4) increasing structural complexity (e.g. shoot biomass) may not always lead to increased faunal survival. The results correspond to those of recent studies in marine and terrestrial landscapes showing widely variable faunal responses to landscape structure among species, geographic location and through time, and imply that seagrass restoration and conservation strategies should incorporate species-specific responses to habitat structure at multiple scales.     

Habitat selection by the common wombat (Vombatus ursinus) in disturbed environments: Implications for the conservation of a ‘common’ species

The construction of habitat models is a repeatable technique for describing and mapping species distributions, the utility of which lies in enabling management to predict where a species is likely to occur within a landscape. Typically, habitat models have been used to establish habitat requirements for threatened species; however they have equal applicability for modelling local populations of common species. Often, few data exist on local populations of common species, and issues of abundance and habitat selection at varying scales are rarely addressed. We provide a habitat suitability model for the common wombat (Vombatus ursinus) in southern New South Wales. This species is currently perceived as abundant throughout its extensive range across temperate regions of eastern Australia, yet little factual survey data exist and populations appear under threat. We use wombat burrows to reflect habitat selection and as our basis for ecological modelling. We found that environmental variables representing proximity to cover, measures of vegetation and proximity to watercourses are important predictors of burrow presence. Extrapolation of habitat models identified an abundance of habitat suitable for burrows. However, burrows in many suitable areas were abandoned. Our estimate of the population size was similar to the total annual mortality associated with road-kill. Theoretically, given the availability of suitable habitat, common wombat populations in the region should be thriving. It seems likely that this area once supported a much higher number of wombats; however limiting factors such as road mortality and disease have reduced the populations. The persistence of wombats in the study region must be supported by migration from other populations. Our findings challenge the perception that wombats are currently common and not in need of monitoring, suggesting that perceptions of abundance are often clouded by socio-political motives rather than informed by biological and ecological factors.     

Extirpation, colonization, and habitat dynamics of a keystone species along an urban gradient

Using 5 years of patch occupancy data for 384 habitat fragments, we evaluated population and habitat dynamics of the black-tailed prairie dog in urban habitat remnants in the rapidly developing landscape of Denver, CO, USA. Specifically, we evaluated the landscape factors, including fragment area, age, and connectivity, that characterize the habitat fragments most likely to be colonized by prairie dogs, as well as those experiencing local extinctions. In addition, we determined which patch types were most often removed by land development. Sites in proximity to colonies were more likely to be colonized by prairie dogs. Local extinctions were most common on isolated colonies, and older and more isolated colonies were more likely to be extirpated by human activity. In general, smaller and older habitat patches were at the highest risk of being lost to land development. Our results provide observations of dynamic changes to the distribution of a potential keystone species in an urban area, which can be used to inform island biogeographic and metapopulation models for wildlife persistence in developing landscapes. Although populations are currently in decline, most local extinctions are the direct result of human activity, and we suggest that prairie dogs in this area can persist with appropriate management.     

A habitat-based population viability analysis for ocelots (Leopardus pardalis) in the United States

Strategies are needed to recover the ocelot Leopardus pardalis from the endangered species list. Recently, a population viability analysis (PVA) was developed which concluded that combinations of different recovery strategies were needed to effectively reduce ocelot extinction probability in the United States (US), with habitat protection and restoration identified as the most effective recovery scenario. We expanded this PVA model by incorporating landscape data to develop a more realistic habitat-based PVA for ocelots in southern Texas. We used RAMAS/gis software to conduct a habitat-based PVA by linking landscape data with a demographic metapopulation model. The primary goal of this study was to provide a model for evaluating ocelot recovery strategies in the US. Each model scenario was simulated 1000 times over 50 years and we defined extinction as one individual remaining. Using the RAMAS/gis program we identified 11 possible ocelot habitat patches (i.e., subpopulations) occurring in southern Texas. In addition, based on the habitat-based PVA model we found that combinations of different recovery strategies were needed to effectively reduce ocelot extinction probability in the US, with reducing road mortality the single most effective strategy. Short-term recovery strategies should include reducing ocelot road mortality, and translocation of ocelots into the US from northern Mexico. Long-term recovery strategies should include the restoration of habitat between and around existing ocelot habitat patches and the establishment of a dispersal corridor between ocelot breeding populations.     

Bird communities in small woods in an agricultural landscape: Effects of area and isolation

The distribution of breeding bird species in 68 small woodlots in two areas of agricultural landscape was investigated. Effects of area, habitat variation, interpatch distance, and distance from extensive woods were analysed with the help of multivariate techniques. No correlation was found between number of breeding bird species and isolation variables, but the degree of isolation was shown to affect the number of bird species restricted to mature woods. Species showed different responses to changes of area or isolation variables. It is concluded that, for several species of woodland birds, patches of mature woodland can be regarded as habitat islands. Some indications are given to apply the regression models found to landscape planning.     

Using multi-scale modelling to predict habitat suitability for species of conservation concern: The grey long-eared bat as a case study

Although spatial scale is important for understanding ecological processes and guiding conservation planning, studies combining a range of scales are rare. Habitat suitability modelling has been used traditionally to study broad-scale patterns of species distribution but can also be applied to address conservation needs at finer scales. We studied the ability of presence-only species distribution modelling to predict patterns of habitat selection at broad and fine spatial scales for one of the rarest mammals in the UK, the grey long-eared bat (Plecotus austriacus). Models were constructed with Maxent using broad-scale distribution data from across the UK (excluding Northern Ireland) and fine-scale radio-tracking data from bats at one colony. Fine-scale model predictions were evaluated with radio-tracking locations from bats from a distant colony, and compared with results of traditional radio-tracking data analysis methods (compositional analysis of habitat selection). Broad-scale models indicated that winter temperature, summer precipitation and land cover were the most important variables limiting the distribution of the grey long-eared bat in the UK. Fine-scale models predicted that proximity to unimproved grasslands and distance to suburban areas determine foraging habitat suitability around maternity colonies, while compositional analysis also identified unimproved grasslands as the most preferred foraging habitat type. This strong association with unimproved lowland grasslands highlights the potential importance of changes in agricultural practices in the past century for wildlife conservation. Hence, multi-scale models offer an important tool for identifying conservation requirements at the fine landscape level that can guide national-level conservation management practices.     

Metapopulation viability analysis of the greater glider Petauroides volans in a wood production area

Successful forest wildlife management is dependent on information that estimates long-term viability of populations in response to different management practices. In this paper we couple information captured in a GIS database, relationships between habitat attributes and habitat quality, and the dynamics of those habitat attributes, to assess the long-term metapopulation viability of a forest-dependent arboreal marsupial, greater glider Petauroides volans Kerr, in the Ada Forest Block in south-eastern Australia. Estimates of the size and spatial distribution of populations in remnant patches of old-growth forest, and the dynamics of key elements of that habitat, are input to ALEX, a computer package for population viability analysis. The model is used to predict the probability of persistence of P. volans within the Ada Forest Block concentrating on scenarios that assess the value of different old-growth patches and the impact of wildfire. We conclude that small patches of old-growth forest ( <20 ha) make almost no contribution to the persistence of the species. In addition, control of wildfire will significantly increase the viability of the species in the remaining habitat.     

Sustaining biodiversity conservation in human-modified landscapes in the Western Ghats: Remnant forests matter

Human-modified tropical landscapes under semi-natural or agro-ecosystems often harbor biodiversity of significant conservation value. In the Western Ghats of India, these ecosystems also provide connectivity between protected areas and other remnant forests. We investigated the conservation value of these landscapes and agro-ecosystems using results from 35 studies covering 14 taxonomic groups. Large, conspicuous taxonomic groups and tree-covered land-use types have received much focus in this area of research in the Western Ghats. We computed a response ratio defined as the log ratio of species richness in human land use to species richness in forest control site from 17 studies. In a meta-analysis, we investigated variation of this ratio across studies with respect to three variables: taxonomic group, the land-use type sampled and the extent of forest cover within the study landscape. Higher forest cover within the landscape emerged as a major positive influence on biodiversity in human-modified landscapes for vertebrates and vegetation while no patterns emerged for invertebrates. Our results suggest that loss of remnant forest patches from these landscapes is likely to reduce biodiversity within agro-ecosystems and exacerbate overall biodiversity loss across the Western Ghats. Conservation of these remnant forest patches through protection and restoration of habitat and connectivity to larger forest patches needs to be prioritized. In the densely populated Western Ghats, this can only be achieved by building partnerships with local land owners and stakeholders through innovative land-use policy and incentive schemes for conservation.     

Small mammals in agricultural landscapes of Prince Edward Island (Canada): Effects of habitat characteristics at three different spatial scales

We examined the influence of habitat characteristics at the microhabitat, macrohabitat, and landscape spatial scales on small mammals occurring in 12 forest patches within four agricultural landscapes of Prince Edward Island (Canada). Landscape features were important determinants of small mammal variables at all levels, but especially at the community level, whereas microhabitat characteristics tended to influence small mammals at the population level. Macrohabitat characteristics had only minor effects on small mammals occurring in our study sites. Species richness was most strongly influenced by patch area, reaching a threshold at forest patches of roughly 8-10 ha. The proportions of both forest and hedgerow cover within 400 m from the study site were also significant determinants of small mammals species diversity, possibly reflecting their ability to perceive suitable habitats, forage in areas outside the forest patches, and/or disperse in agricultural landscapes. At least one small mammal species (Napaeozapus insignis) benefitted from the presence of agricultural fields at distances up to 1000 m. Tamias striatus benefitted from the presence of hedgerow cover within 400 m from forest patches, possibly allowing them to move between forest patches. Clearly, the maintenance of forest patches of 8-10 ha and of forest cover within 400 m from them is fundamental for the conservation of small mammals inhabiting agricultural landscapes on the Island. Conservation strategies should also consider the establishment of more effective regulations to prevent and/or reduce hedgerow removal on Prince Edward Island.     

Predicting potential habitat and population size for reintroduction of the Far Eastern leopards in the Russian Far East

The Far Eastern Leopard (Panthera pardus orientalis; Schlegel, 1857) is perhaps the world’s most endangered large felid subspecies occurring in a single population of ?30 adults, and faces immediate risk of extinction unless additional populations can be established within its historical range in the Russian Far East. We used locations of leopard tracks (and their ungulate prey) collected from snow track surveys from 1997 to 2007 to develop resource selection functions (RSF) to identify potential habitat for reintroduction. We compared models that include prey versus those based on landscape covariates, and also included covariates related to human-induced mortality. To estimate potential population size, we used a habitat-based population estimate based on the ratio of population size and RSF value of occupied range. Far Eastern leopards selected for areas with high ungulate density, lower-elevation Korean pine forests on southwest facing slopes, and in areas far from human activity. Using this RSF model, we identified a total of 10,648 km² in eight patches >500 km² of potential Far Eastern leopard habitat that could harbor a potential population of 105.3 (57.9–147.2) adults. In combination with the existing population, successful reintroductions could result in a total of 139.2 (76.5–194.6) adult leopards, a 3–4-fold increase in population size. Our habitat models assist the reintroduction planning process by identifying factors that predict presence and potential suitable habitat. Identifying the highest quality, most connected patches, in combination with appropriate selection and training of released animals, is recommended for successfully reintroducing Far Eastern leopards, and potentially other endangered carnivores into the wild.