Wildlife Habitat Use Research Articles

Lost in translation? Insights into caribou habitat selection from forest inventory data

The gap between research and its implementation is an impediment to conservation of the environment. Translating science into actionable management and policy requires effective communication and collaboration among scientists, practitioners, and policy-makers. Ecologists routinely rely on spatial data to describe wildlife distributions; however, habitat definitions vary by species, and data sources often differ from those used by land managers. Finding commonalities in the language and data used to plan for industrial activities and wildlife conservation may help address the research-implementation gap for threatened species like woodland caribou. We built resource selection functions for caribou using Alberta Vegetation Index (AVI) habitat data, which is employed by the Alberta forest industry for landbase planning. Our goal was to bridge the research-implementation gap by providing the forest industry with tools to facilitate planning for caribou conservation within their jurisdiction. In contrast to previous studies that highlighted shortcomings in AVI data for predicting wildlife habitat use, we found that resource selection function models that combined AVI data with complementary covariates validated well to predict caribou habitat use. We suggest that by using a data source familiar to land managers, ecologists can facilitate the bridging of the research-implementation gap without compromising the quality of ecological modeling.

Grizzly bear response to fine spatial and temporal scale spring snow cover in Western Alberta.

Snow dynamics influence seasonal behaviors of wildlife, such as denning patterns and habitat selection related to the availability of food resources. Under a changing climate, characteristics of the temporal and spatial patterns of snow are predicted to change, and as a result, there is a need to better understand how species interact with snow dynamics. This study examines grizzly bear (Ursus arctos) spring habitat selection and use across western Alberta, Canada. Made possible by newly available fine-scale snow cover data, this research tests a hypothesis that grizzly bears select for locations with less snow cover and areas where snow melts sooner during spring (den emergence to May 31st). Using Integrated Step Selection Analysis, a series of models were built to examine whether snow cover information such as fractional snow covered area and date of snow melt improved models constructed based on previous knowledge of grizzly bear selection during the spring. Comparing four different models fit to 62 individual bear-years, we found that the inclusion of fractional snow covered area improved model fit 60% of the time based on Akaike Information Criterion tallies. Probability of use was then used to evaluate grizzly bear habitat use in response to snow and environmental attributes, including fractional snow covered area, date since snow melt, elevation, and distance to road. Results indicate grizzly bears select for lower elevation, snow-free locations during spring, which has important implications for management of threatened grizzly bear populations in consideration of changing climatic conditions. This study is an example of how fine spatial and temporal scale remote sensing data can be used to improve our understanding of wildlife habitat selection and use in relation to key environmental attributes.

Wildlife mortality on roads and railways following highway mitigation

AbstractWildlife mortality caused by collisions with vehicles on roads is increasingly and effectively mitigated with exclusion fencing and crossing structures, but this solution potentially changes wildlife habitat use and distribution to increase the risk of mortality on adjacent, unmitigated railways. We investigated this potential side‐effect of mitigating the TransCanada Highway, which was completed in sections between 1983 and 2013, on the rate of wildlife mortality on the nearby transcontinental mainline of the Canadian Pacific Railway in Banff National Park. For each transportation class (highway and railway), we calculated collision rate as the number of collisions per year and km for two guilds (carnivores and ungulates) before and after mitigation occurred between 1981 and 2014. We constructed additional models for each transportation class and each of four species groups with adequate sample sizes: elk (Cervus canadensis), other ungulates (family Cervidae), bears (Ursus spp.), and coyotes (Canis latrans). Across guilds, mortality rates declined after mitigation, particularly on the highway (as expected) and most strongly for ungulates. For individual species groups, mortality on the railway for elk was best predicted by year and population size, without the inclusion of mitigation status on the adjacent highway. However, collision rates on the railway increased after mitigation for other ungulates (mostly deer, Odocoileus spp.) while also increasing over time. Collision rates on the railway increased over time for bears, but not in relation to highway mitigation. We found no evidence that the spatial distribution of collisions on the railway changed after highway mitigation, as might be expected from a funneling effect of crossing structures. Our results support and extend previous work demonstrating that exclusion fencing and wildlife crossing structures reduce wildlife mortalities on the highway at this location, and provide limited evidence, for other ungulates alone, that such mitigation may increase mortality on the adjacent railway. Similar analyses are warranted in other locations, particularly mountainous regions, where major transportation features often occur in close proximity.

Spatial ecology and multi-scale habitat selection by Western Painted Turtles (<i>Chrysemys picta bellii</i>) in an urban area

As urban centres expand, knowledge on the habitat and space use of native wildlife, particularly long-lived species, is required for proper management. Our objective was to understand space requirements and key habitat features necessary for long-term persistence of Western Painted Turtles (Chrysemys picta bellii) living in a Canadian urban park. Using radio telemetry, we examined seasonal habitat selection and space use over two years, 2015–2016 (n = 23), and 2016–2017 (n = 29) in Regina, Saskatchewan. Daily movements and home ranges of males and females were smaller during emergence than during nesting or post-nesting phases of the active season. Turtles inhabiting marsh sites had 2- and 4-times larger daily movements and home ranges compared to turtles inhabiting the creek. Turtles selected the shoreline habitat over urban/parkland and open water. Turtles used marsh-shoreline habitats non-randomly, selecting accessible shoreline with large trees in the active season. In contrast, turtles used creek-shoreline habitat according to availability. Overwintering sites selected by turtles were warmer and deeper than random available sites, with no difference in dissolved oxygen level. However, water was hypoxic for most overwintering sites. Our results show that turtles range widely, requiring 20–60 ha throughout the year. Urban park areas should be managed to provide accessible shorelines with a combination of cover and open basking areas. Critically, careful attention needs to be paid to managing water depth so that over-wintering sites remain viable.

Habitat use, preference, and utilization distribution of two crane species (Genus: Grus) in Huize National Nature Reserve, Yunnan-Guizhou Plateau, China.

Understanding the habitat use and spatial distribution of wildlife can help conservationists determine high-priority areas and enhance conservation efforts. We studied the wintering habitat use, preference, and utilization distribution of two crane species, that is, the black-necked crane (Grus nigricollis, Przevalski, 1876) and common crane (Grus grus, Linnaeus, 1758), in Huize National Natural Reserve, Yunnan–Guizhou Plateau, southwestern China. Line transects indicated that anthropogenic farmland habitat was highly utilized and was positively selected by both crane species (>90% of flocks observed for both species). Black-necked cranes preferred marshland in spring (February and March) but avoided grassland during the entire wintering period, whereas common cranes avoided both marshland and grassland throughout the entire period. The two cranes species had communal nightly roosting sites and separate daily foraging sites. Black-necked cranes were distributed within two km (1.89 ± 0.08 km) of the roosting site, covering an area of 283.84 ha, with the core distribution area encompassing less than 100 ha. In contrast, common cranes were distributed far from the roosting site (4.38 ± 0.11 km), covering an area of 558.73 ha, with the core distribution area encompassing 224.81 ha. Thus, interspecies competition may have influenced the habitat preference and spatial distribution divergence of these two phylogenetically related species. This study should help guide habitat management as well as functional zoning development and adjustment in the future. Based on our results, we recommend restoration of additional wetlands, retention of large areas of farmland, and protection of areas that cranes use most frequently.

RANCANG BANGUN KAMPUNG EKOWISATA BURUNG MALEO GUNUNG (Aepypodius arfakianus) BERBASIS KEARIFAN LOKAL MASYARAKAT HATAM UNTUK MENINGKATKAN EKONOMI DAN KONSERVASI SATWA ENDEMIK PAPUA DI PEGUNUNGAN ARFAK

<p>The wildlife on earth is increasingly urged by human life, where forest functions are used as residential and agricultural land. Illegal logging causes destruction of habitat and excessive use of wildlife causing damage to ecological functions in general. Uncontrolled utilization of eggs and fowls of wattled brushturkeys will accelerate the extinction of these animals in natural habitats. On the other hand the dependence on protein and economic needs of communities in the Arfak Mountains is high as evidenced by the widespread of hunting activities conducted with various purposes of utilization. Breeding efforts for the purpose of utilization need to be given attention in relation to the conservation and fulfillment of human needs. Efforts to increase the population of the bird are made through the modification of breeding and captive breeding efforts so as to encourage the acceleration of the bird population in nature and on the other hand the community interest in the fulfillment of protein and economic needs can be accommodated. Therefore, basic knowledge of the wisdom of local communities are need to support the sustainability of this bird in nature. Studies of local community wisdom and natural nest site coverage data need to be immediately obtained to fullfil the purpose. This baseline data is a reference to the establishment of appropriate breeding sites and management is expected to increase the acceleration of this bird population in nature as well as economic improvement through an ecotourism village. This research was conducted in Minyambouw District around Arfak Mountains Nature Reserve for 2 years (2013-2014). The first year study aims to find out the location of active nesting sites and strategic location to serve as a breeding model. Some active bird nests of the bird have been found in the forest of Syoubri village and then mapped based on GPS data. In the second year, the collection of cultural data of the community (local wisdom) as the basis of customary rules that bind the community. Some people (50%) still do hunting for family consumption and income. To overcome this, the community agreed and happy to make the bird and its nest as a tourist attraction. In relation to that there is a need to do management of ecological tourism for the community and creation of a captive breeding programme through a hatchery effort on wattled brushturkey birds.<strong></strong></p>

Distribution and occupancy of wolverines on tundra, northwestern Alaska

ABSTRACTUnderstanding wildlife distribution and habitat use is needed for effectively balancing resource development, wildlife conservation, and Alaska Native subsistence on the North Slope of Alaska, USA. This region includes the National Petroleum Reserve‐Alaska (NPR‐A), a 96,000‐km2remote area of largely undeveloped lands that is important for wildlife, including caribou (Rangifer tarandus), wolves (Canis lupus), and wolverines (Gulo gulo). We focused our study on spring distribution and occupancy of wolverines in the NPR‐A because a baseline distribution estimate is required to understand current distribution and track changes over time. We conducted aerial surveys of wolverine tracks in snow during March and April of 2014 and 2015, surveying over 84,400 km2using 100‐km2hexagonal sampling units. We used hierarchical Bayesian occupancy modeling to determine wolverine distribution and estimate probability of occupancy within each hexagon, relative to measured covariates with potential to affect either detection or occupancy. Probability of wolverine occupancy increased as well‐drained soils increased, suggesting that wolverines prefer drier areas or habitat features associated with well‐drained soils. In addition, as standard deviation of elevation increased, wolverine occupancy also increased, indicating that wolverines may prefer areas with more rugged and variable terrain. Mean elevation was not retained as a covariate in the best‐fitting model, supporting the importance of terrain ruggedness rather than elevation on wolverine distribution within the NPR‐A. Spatially, areas of highest wolverine occupancy occurred within the southern and northeastern portions of the study area, with lowest occupancy in the northern portion of the study area west of Teshekpuk Lake. Based on the spatial pattern of wolverine probability of occupancy, we proposed 4 potential wolverine management zones with varying priorities for monitoring and managing wolverine populations. © 2018 The Wildlife Society.

Incorporating productivity as a measure of fitness into models of breeding area quality of Arctic peregrine falcons

Using empirical location data from individuals to model habitat quality and species distributions is valuable towards understanding habitat use of wildlife, especially for conservation and management planning. Incorporating measures of reproductive success or survival into these models helps address the role of vital rates (a surrogate of fitness) in affecting a species' distribution. We used 24‐year datasets of Arctic peregrine falcon Falco peregrinus tundrius nest‐site locations and productivity from the Colville River Special Area, Alaska, USA to model suitability of breeding habitat and the relative quality of used and potential nest sites. We used zero‐inflated negative binomial regression models and covariates describing nest‐site productivity, area of surrounding prey habitat, geology, topography and land‐cover type to model and predict intensity of Arctic peregrine falcon nest‐site use along the Colville River, and developed a predictive map of intensity of nest‐site use. Regions of higher predicted intensity of use were characterized by steeper slopes, greater area of prey habitat, and higher average productivity, which are likely attributed to minimizing predation risk, gaining advantages for hunting, having sufficient prey resources, site quality, and overall fitness. Including productivity in intensity of nest‐site use models improved the models, supporting our supposition that adding a fitness parameter enhanced the predictive capability of the species distribution model. Areas predicted to have higher intensity of use by our model can be used to focus efforts of continued protection of areas with frequently occupied and productive nest sites, and conversely, identify areas where protection of nest sites is likely to have few conservation benefits.

Evaluating efficacy of fence markers in reducing greater sage-grouse collisions with fencing

Anthropogenic infrastructure routinely interferes with wildlife movement, habitat use, and survival. Grouse in the family Phasianidae may be particularly susceptible to collisions with fences due to their morphology and life history. Because many Phasianid species are of conservation concern, managers often deploy markers on fences to reduce collision-associated mortality. However, scarce information on the effectiveness of different marker styles or the effects of local and landscape features on collision risk exists. Our objectives were to (1) determine the effectiveness of different marker styles in reducing collisions, (2) estimate the effects of local and landscape features on collision risk, and (3) evaluate an existing greater sage-grouse (Centrocercus urophasianus) collision risk model. We conducted greater sage-grouse collision surveys within Sublette County, Wyoming, USA in March and April of 2014 and 2015. Data were analyzed in a multi-scale occupancy model accounting for incomplete detection of collisions. We found substantial evidence for the ability of all markers to reduce collisions (~57% reduction), with little difference between the tested marker types. We found strong evidence for lower collision probabilities at fences with wood posts and on fences farther from leks. Our results also indicated a negative relationship between collision probabilities and the difference between fence and vegetation heights. We observed little evidence for differences in collision risk between areas defined as “high” or “moderate” risk in a pre-existing collision risk map. We recommend integrating fence marking into conservation practices requiring fencing, and prioritizing fence marking near leks in areas with greater fence exposure.

Diversity and activity patterns of sympatric animals among four types of forest habitat in Guanyinshan Nature Reserve in the Qinling Mountains, China.

Environmental heterogeneity contributes to various habitats and may influence the diversity and activity patterns of wildlife among habitats. We used camera traps to assess wildlife habitat use in Guanyinshan Nature Reserve from 2009 to 2012. We focused on four types of habitat including open areas with gentle slope (<15°) (Type1), low elevation areas (about 1500-1700m) with high bamboo coverage (Type2), high elevation areas (about 2100-2300m) with high canopy coverage (Type3), and wildlife migration passages (Type4). We analyzed the differences in species richness, relative abundance index (RAI), species diversity, and animals' activity pattern among habitats. Total six species were analyzed on activity pattern, which are Takin (Budorcas taxicolor), tufted deer (Elaphodus cephalophus), Himalayan goral (Naemorhedus goral), wild boar (Sus scrofa), golden pheasant (Chrysolophus pictus), and porcupine (Hystrix hodgsoni). The results are (1) that there were significant differences in richness and RAIt among habitats; (2) Type4 habitat had the highest richness and RAIt while Type2 had the highest species diversity; giant pandas were found in these two habitats; (3) there were significant differences in species' activity during daytime and nighttime; and (4) differences appeared in habitat preference of the most abundant species. Takin and tufted deer preferred Type1, Himalayan goral preferred Type2, and golden pheasant preferred Type3. Type4 habitat was used by most animals. All these revealed that habitat heterogeneity plays an important role in species diversity and the importance for conservation.

The vegetation and wildlife habitats of the Savuti-Mababe-Linyanti ecosystem, northern Botswana

This study classified the vegetation of the Savuti-Mababe-Linyanti ecosystem (SMLE), northern Botswana and developed a detailed map that provides a reliable habitat template of the SMLE for future wildlife habitat use studies. The major vegetation units of the SMLE were determined from satellite imagery and field visits and then mapped using Landsat 8 and RapidEye imagery and maximum likelihood classifier. These units were sampled using 40 m x 20 m (800 m²) plots in which the coverage of all plant species was estimated. Non-metric multidimensional scaling (NMS) demonstrated that plant communities were determined by gradients in soil texture or fertility and wetness. NMS 1 represented a gradient of soil texture with seven woodland communities on sandy soils (sandveld communities and Baikiaea forest) dominated by Baikiaea plurijuga in Baikiaea forest and Terminalia sericea and Philenoptera nelsii in sandveld, with various indicator species differentiating the various sandveld community types. Mopane woodland further from and riparian woodland adjacent to permanent water was common on less sandy alluvial soils. Mineral-rich, heavy clay soils in the sump of a large paleolake system support open grassland and mixed Senegalia/Vachellia (Acacia) savanna, with the mineral-rich soils supporting grasses high in minerals such as phosphorus, calcium, sodium and potassium, and thus this region is a critical wet season range for migratory zebra. Taller, high-quality grasses in the mosaic of sandveld and mopane woodland communities provide critical grazing for taller grass grazers such as buffalo, roan and sable antelope, whereas wetland communities provide reliable green forage during the dry season for a variety of herbivores, including elephant. This study has demonstrated how large-scale environmental gradients determine functional habitat heterogeneity for wildlife.Conservation implications: Our study demonstrated that the functionality of protected areas is determined by large-scale environmental gradients. Thus conservation science must aim to ensure that protected areas cover the full range of key environmental gradients in a region (soil texture and wetness in our study). Our habitat map provides a data base for wildlife habitat use studies in the region.

Fine-scale temporal and spatial population fluctuations of medium sized carnivores in a Mediterranean agricultural matrix

Many Mediterranean ecosystems are human-dominated landscapes comprising a mosaic of agricultural, natural and semi-natural habitats alongside urban areas. The size, spatial pattern and connectivity of these “mosaic landscapes” promote changes in wildlife behavior, movement patterns and habitat use. Study how spatiotemporal landscape changes impact the spatial dynamics of a mammalian carnivore guild. We quantified multi-season activity rates/density from camera trap encounters using N-mixture models. One hundred cameras were located at 25 sites, divided into five categories: nature reserve; large natural area; vineyards within natural area; vineyards near settlements; vineyards within the core agricultural matrix. Golden jackals (Canis aureus) were active in anthropogenic modified landscapes. Red foxes (Vulpes vulpes) avoided the core activity areas of jackal during summer and restricted their activity to their peripheries. European badgers (Meles meles) were active in natural patches during winter, but shifted their activity during summer to agricultural fields embedded within natural patches. Feral and wilds cats (Felis silvestris) were highly active in the natural patches during winter and shifted their activity to the agricultural matrix during summer. Intra-guild spatio-temporal activity patterns of carnivores in mosaic landscapes are distinct and unique to each species. The patterns were affected by season, land-use, and jackal activity rates, reflecting inter-specific resource-dependent competitive interactions. The findings highlight the complexity of intra-guild space-use patterns, and shed doubt on the effectiveness of simple solutions to landscape conservation problems.

California Spotted Owl (Strix occidentalis occidentalis) habitat use patterns in a burned landscape

ABSTRACT Fire is a dynamic ecosystem process of mixed-conifer forests of the Sierra Nevada, but there is limited scientific information addressing wildlife habitat use in burned landscapes. Recent studies have presented contradictory information regarding the effects of stand-replacing wildfires on Spotted Owls (Strix occidentalis) and their habitat. While fire promotes heterogeneous forest landscapes shown to be favored by owls, high severity fire may create large canopy gaps that can fragment the closed-canopy habitat preferred by Spotted Owls. We used radio-telemetry to determine whether foraging California Spotted Owls (S. o. occidentalis) in Yosemite National Park, California, USA, showed selection for particular fire severity patch types within their home ranges. Our results suggested that Spotted Owls exhibited strong habitat selection within their home ranges for locations near the roost and edge habitats, and weak selection for lower fire severity patch types. Although owls selected high contrast...

Impacts of Bush Encroachment on Wildlife Species Diversity, Composition, and Habitat Preference in Ol Pejeta Conservancy, Laikipia, Kenya

Savannah ecosystems are currently facing a biome shift that changes grasslands to woody dominated landscapes, attributable to habitat degradation. In Ol Pejeta Conservancy (OPC), Euclea divinorum, an unpalatable and invasive woody species, is expanding to former savannah ecosystems with potential effects on herbivores key resources, wildlife species diversity, composition, and habitat use. We investigated wildlife species diversity, composition, and habitat preference or avoidance by wildlife in the conservancy. Infrared camera traps were deployed at the centroids of 2 km by 2 km, 50 cm above ground surface for 14 days and nights with 9 camera traps in each habitat type. Shannon wiener index revealed that wildlife species diversity was highest in E. divinorum dominated habitats and lowest in open grassland. Hierarchical Cluster Analysis revealed level of similarity in wildlife species composition between E. divinorum and mixed bushland. Jacobs index revealed that E. divinorum and mixed bushland were avoided by all guilds; however E. divinorum was significantly avoided while A. drepanolobium and open grassland were both preferred by all guilds. However, A. drepanolobium dominated habitats were significantly preferred compared to open grasslands. The findings are useful in management of sustainable ecosystems.

Testing remotely-sensed predictors of meso-carnivore habitat use in Mediterranean ecosystems

The legacy of human use of Mediterranean ecosystems results in spatial and temporal heterogeneity of resources for wildlife. Understanding wildlife use of these ecosystems may be improved by including information on ecosystem type, structure, and function extracted from remote sensing data. To assess whether we can improve our understanding of wildlife-habitat use by including information on ecosystem type, structure and function. We tested whether remote sensing derived descriptors of ecosystem type, structure (tree cover and patch size) and function (productivity and stress) determine the habitat of stone martens (Martes foina), common genets (Genetta genetta), and European badgers (Meles meles) in southern Portugal. We linked radio-tracking data from five stone martens, five genets and eight badgers with aerial photography, and some spectra-selectivity to classify vegetation, its structure, productivity and drought stress. Statistically-derived generalized linear mixed regression models using combinations of remotely sensed descriptors of ecosystem type, structure and function, performed better than single ecosystem type descriptors. Inclusion of information on ecosystem functioning in predictive models of habitat use is more informative than ecosystem type alone, suggesting functional relationships between wildlife and their habitat. However, inclusion of both ecosystem type and function maybe limited to finer spatial resolutions. Our results illustrate the untapped potential of remote sensing to provide detailed descriptors of habitat at adequate spatial scales, now that they are freely available and are systematically collected over space and time. This information adds useful insights on wildlife-habitat relationships under changing patterns of land use and climate.

Effect of the plantation age on the use of Eucalyptus stands by medium to large-sized wild mammals in south-eastern Brazil

Abstract: In Sao Paulo State, in Southeastern Brazil, the Eucalyptus plantations have been replacing large areas which were formerly occupied by pastures used for livestock production. Such land use change may affect the habitat use by wildlife in these anthropic landscapes. In this region, the commercial Eucalyptus plantations of the paper and cellulose industry usually take from 6 to 7 years to be harvested. During its production cycle, the Eucalyptus stands vary from an open savanna-like environment just after plantation, when plants still resemble bushes, to a forest-like environment with densely distributed 18-meter high trees. Previous studies show that the Eucalyptus plantations in Southeastern Brazil are used by generalist species including medium and large sized mammals. However, the possible influence of such dramatic temporal environmental heterogeneity on the wildlife habitat use in Eucalyptus plantations is still unknown. In this study, which follows a classic stratified design, we evaluate the influence of the Eucalyptus stand age on the local patterns of distribution and abundance of middle to large-sized wild mammals. Our results show an increase not only in their species richness, but also in their frequency of occurrences along the commercial cycle of the Eucalyptus plantations with a steep decline in both before harvest. This pattern may be related to weed control practices which significantly reduce the understory vegetation, in especial at the end of the commercial cycle while preparing for harvest. Future studies should prioritize the possible variation on the trophic structure in the Eucalyptus plantations along commercial cycles as a response of wildlife friendly silvicultural/agricultural management practices.

Visual obstruction as a method to quantify herbaceous biomass in southern African semi-arid savannas

Biomass of aboveground vegetation is a useful descriptor for studies of grazing, fire and wildlife habitat use in grassland systems. The traditional method to estimate biomass, hand-clipping, is time intensive and other indices of biomass have been used successfully. In southern Africa, the disc pasture meter has been the tool of choice and the use of visual obstruction has been much less prevalent than in North America. Our goal was to determine if visual obstruction could be used as a correlate to aboveground grass biomass in grassland systems in Namibia. We gathered clipping and visual obstruction samples at three study sites in Highland Savanna and Woodland Savanna in northern Namibia. Dry biomass of grass was correlated with visual obstruction readings when samples from all study sites were pooled (r 2 ≤0.64, P<0.0001), but the strength of the relationship varied among the three study sites. We also evaluated the number of samples needed to characterise biomass at a study site. Variation in the cumulative mean was very low at sample sizes of 15–20 samples. Visual obstruction can be a useful method to evaluate biomass of grassland systems in a quick manner.

Potential environmental effects of pack stock on meadow ecosystems of the Sierra Nevada, USA

Pack and saddle stock, including, but not limited to domesticated horses, mules, and burros, are used to support commercial, private and administrative activities in the Sierra Nevada. The use of pack stock has become a contentious and litigious issue for land management agencies in the region inter alia due to concerns over effects on the environment. The potential environmental effects of pack stock on Sierra Nevada meadow ecosystems are reviewed and it is concluded that the use of pack stock has the potential to influence the following: (1) water nutrient dynamics, sedimentation, temperature, and microbial pathogen content; (2) soil chemistry, nutrient cycling, soil compaction and hydrology; (3) plant individuals, populations and community dynamics, non-native invasive species, and encroachment of woody species; and (4) wildlife individuals, populations and communities. It is considered from currently available information that management objectives of pack stock should include the following: minimise bare ground, maximise plant cover, maintain species composition of native plants, minimise trampling, especially on wet soils and stream banks, and minimise direct urination and defecation by pack stock into water. However, incomplete documentation of patterns of pack stock use and limited past research limits current understanding of the effects of pack stock, especially their effects on water, soils and wildlife. To improve management of pack stock in this region, research is needed on linking measurable monitoring variables (e.g. plant cover) with environmental relevancy (e.g. soil erosion processes, wildlife habitat use), and identifying specific environmental thresholds of degradation along gradients of pack stock use in Sierra Nevada meadows.

An evaluation of habitat selection of Asiatic black bears in a season of prevalent conflicts

Abstract Identifying the relationships between human land use and wildlife habitat use is an essential component in any attempt to mitigate human–wildlife conflict and conserve imperilled wildlife populations. We studied habitat selection by Asiatic black bears (Ursus thibetanus) by employing a resource selection function (RSF), using GPS relocation data for 9 bears in 2008 and 2009. We focused on habitat selection in summer when human–bear conflicts are most frequent in the central Japanese Alps. Logistic regression indicated that bears were positively associated with red pine (Pinus densiflora) forest and regenerating lands and negatively associated with both larch (Larix leptolepis) and coniferous plantation. Almost all bears tended to select areas with steep slopes that were close to roads and rivers. An index of human–bear encounter risk, estimated using the predicted RSF map and road density, suggested that only 5.3% of the study area was secure habitat with low human access for bears. Selection by ...

基于核密度估计的动物生境适宜度制图方法

Habitat suitability mapping can provide information on spatial variation of wildlife habitat suitability which is useful for wildlife population management and conservation planning. The key issue of habitat suitability mapping is how to construct habitat suitability model( HSM). Existing presence-only based methods of constructing HSM cannot explicitly express the quantitative relationship between wildlife habitat suitability and environmental factors. So the resulted HSM would be insufficient to express the ecological effects of environmental factors on wildlife habitat use. In this paper we proposed a kernel density estimation-based method of using wildlife occurrence data to construct HSM for wildlife habitat suitability mapping,which can obtain the quantitative ecological relationship between habitat suitability and environmental factors. Under the assumption that habitat should be more suitable where wildlife presented more frequently,the presence probability density function( PDF) estimated from wildlife occurrence data was used to express the quantitative ecological relationship between habitat suitability and each individual environmental factor. Then,assuming that habitat suitability is determined by the limiting factor,a minimum operation was applied to construct the final HSM by synthesizing all these relationships on an environmental factor set. In the case study we applied the proposed kernel density estimation-based method to habitat suitability mapping of the White-tailed deer( Odocoileus virginianus) in Voyageures National Park based on 365 deer occurrence points from aerial survey and environmental data characterizing its living environment,with the aid of geographic information system techniques. The environmental factors selected were snow depth,land cover type,forest edge length,and slope gradient. Cross validation was used to evaluate the performance of the proposed method. Results showed that the mean of continuous Boyce Indexes calculated from 10 repetitions of 2-fold cross validation was 0.75 with a standard deviation of 0. 11. This suggests that the HSM from the proposed method has a good predictive capability. The proposed kernel density estimation-based method well captures the ecological effects of environmental factors on the wildlife habitat use in the form of quantitative relationship between wildlife habitat suitability and environmental factors. From the perspective of model interpretability,the proposed method is better than other HSM-constructing methods.