No abstract

One difficulty in the conservation of endangered wildlife is the lack of reliable information on its status. This lack of knowledge can often be attributed to financial and logistic constraints as well as the lack of trained personnel to collect data. We test a simple method to study bears in the southern Balkans by inspecting power poles, which are used by bears for marking and rubbing purposes. We created a network of barbed-wire fitted poles for the collection of hair samples, evenly distributed throughout six study areas. During 87 sampling sessions in the main study area, we collected 191 samples and identified six microsatellite loci that were variable enough for individual bear identification. The most and best-quality hair samples were collected during the mating period, and DNA was most successfully extracted from samples remaining <4 weeks in the field. In the six study areas, we identified 47 bears. An advantage of using power poles for hair sampling is their availability and accessibility; no bait is required, and the network can be easily set up. A drawback may be an unequal capture probability of sex and age classes of bears. Despite this limitation, using power poles proved to be a simple and cheap method for the noninvasive genetic study of bears that did not require any prior knowledge on habitat use and activity patterns. The method is suitable for large-scale surveys to estimate distribution and relative densities of bears and could also be applied for studying other species.

Orphaned bears have been captive-reared and released back to the wild for more than 3 decades, often without a clear understanding of their fates because post-release monitoring is not a common practice. As a result, management agencies lack efficacy data on post-release success rates and are often reluctant to encourage increased use of this technique. We evaluated the potential management and conservation implications of releasing captive-reared bears by documenting post-release survival, causespecific mortality, human conflict activity, movements, and reproduction for 550 American black, brown and Asiatic black bears reared in 12 captive-rearing programs around the world. Survival rates in these programs ranged from 0.50 to 1.00 and were similar among the 3 species. The primary causes of mortality were sport hunting and road kills for American black bears, intra-specific predation and illegal kills for brown bears, and natural mortalities and illegal kills for Asiatic black bears. Although American and Asiatic black bears were involved in conflicts post-release, the majority of released bears (94%) were not documented in conflict situations. Movement patterns of captive-reared American black and brown bears showed no homing tendencies toward their rearing facility. Twenty captive-reared bears produced 21 litters. Our analyses reduce many of the uncertainties surrounding the fate of bears released as yearlings and provide evidence that releasing captive-reared bears is a defensible management alternative. Ó 2015 The Wildlife Society.

Understanding the mechanisms and patterns involved in population recoveries is challenging and important in shaping conservation strategies. We used a recovering rear-edge population of brown bears at their southernmost European range in Greece as a case study (2007-2010) to explore the recovery genetics at a species' distribution edge. We used 17 microsatellite and a mitochondrial markers to evaluate genetic structure, estimate effective population size and genetic diversity, and infer gene flow between the identified subpopulations. To understand the larger picture, we also compared the observed genetic diversity of each subpopulation with other brown bear populations in the region. The results indicate that the levels of genetic diversity for bears in western Greece are the lowest recorded in southeastern Europe, but still higher than those of other genetically depauperate bear populations. Apart from a complete separation of bear populations in eastern and western Greece, our results also indicate a considerable genetic sub-structuring in the West. As bear populations in Greece are now recovering, this structure is dissolving through a "recovery cascade" of asymmetric gene flow from South to North between neighboring subpopulations, mediated mainly by males. Our study outlines the importance of small, persisting populations, which can act as "stepping stones" that enable a rapid population expansion and recovery. This in turn makes their importance much greater than their numeric or genetic contribution to a species as a whole.

Alpine ecosystems are particularly vulnerable to climate change. For widely distributed alpine specialists, rear‐edge populations are disproportionately important; it is expected that climate change will reduce their occupancy ranges due to the loss of suitable habitats and connectivity among them. Using four alpine bird species inhabiting the southwestern Palearctic as models, we aim to study which and how environmental factors influence habitat suitability, identify mountain areas with suitable habitat, estimate the probabilities of hosting breeding populations for these areas, and predict how habitat suitability and breeding occupancy will change under future climate scenarios. We used a species distribution modeling approach to obtain habitat suitability maps for four biological seasons and assessed the importance and effects of climatic and landscape variables for the studied species. We also assessed the probability of occupancy of potential breeding patches using available systematic distribution data, and projected our habitat suitability and occupancy models to future climate conditions. Our results indicated that the habitat suitability of rear‐edge alpine specialists was limited mainly by climatic factors, restricting their suitable areas to the highest mountains where cold climate persist. The actual occupancy of the potential breeding patches was determined by their size, landscape connectivity and habitat quality. For the period 2041–2060 we predicted a substantial reduction of suitable habitats that varied across seasons and species, and a breeding occupancy range loss that varied across mountain ranges and species. Thus, these alpine bird species, currently not considered as threatened, merit a review of their conservation status. Common distribution patterns and potentially similar responses to climatic change suggest that our findings might be applicable for other rear‐edge alpine species. Our study identified specific mountain systems where research and conservation efforts should focus for the conservation of alpine biodiversity in the southwestern Palearctic.