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The political isolation during the communist regime and the economic crisis that followed its downfall adversely affected the conservation of brown bears (Ursus arctos) in Albania. In 2008–2009 we conducted questionnaires and field surveys in southeastern Albania to determine the presence of bears and evaluate bear–human interactions, and on-site inspections to record the status of bears held in captivity. We recorded bears mainly in the eastern and southeastern part of the study area and documented wide-scale bear–human conflicts, which often resulted in the killing and a generally negative public perception of bears. We documented 25 bears in captivity, often under marginal welfare conditions and noted wild-born cubs that were maintained in captivity to meet the demand for captive bears. We recommend additional studies to better evaluate brown bear status; nation-wide education on species conservation needs and how to mitigate negative interactions; and efforts to improve welfare of bears in captivity.
Brown bears (Ursus arctos) are generally solitary animals, although they are known to aggregate at concentrated food resources. Using remote cameras, we documented brown bears aggregating while scavenging a whale carcass from 19 May to 17 September 2010 in Glacier Bay National Park, Alaska, USA. Such aggregations have not been reported in Glacier Bay, a recently deglaciated fjord where bear food resources are dispersed and less diverse than in other regions of coastal Alaska. We documented multiple brown bears and wolves (Canis lupus) scavenging the carcass—at times, simultaneously. This study provided a rare opportunity to document brown bear–wolf interactions over several months associated with a large-magnitude resource event with little evidence of aggression between species. Our results suggest that the humpback whale (Megaptera novaeangliae) carcass provided a substantial food resource for brown bears and wolves in Glacier Bay, potentially influencing space use and interspecific interactions.
Managers often must decide whether to use non-lethal intervention (e.g., hazing or relocation) or lethal removal for resolving bear–human conflicts. Bears with a history of anthropogenic food use are less likely to respond favorably to non-lethal intervention. Stable isotope analysis can be a useful tool to determine a bear's history of anthropogenic food use. We analyzed nitrogen (N) and carbon (C) stable isotopes in 51 hair samples collected between 1991 and 2006 from 30 grizzly bears (Ursus arctos), and their likely food items, from the oilfield region of Alaska's Arctic Coastal Plain (USA) to evaluate the feasibility of using stable isotopes to identify human food use in bears without direct observation. δ15N values varied by >4‰, indicating a trophically diverse diet. We found differences in isotopic values between bears that we had observed on a diet of natural foods (NF) only and those on a predominantly anthropogenic diet (food-conditioned [FC]). For 12 FC and 15 NF bears, mean δ15N values were 6.6‰ (0.26 SE) and 4.8‰ (0.12 SE) and mean δ13C values were −20.4‰ (0.3 SE) and −23.0‰ (0.14 SE), respectively. We confirmed that 3 putative NF bears whose home ranges overlapped the oilfields were likely NF bears. Isotope analysis confirmed visual observations of bear feeding behavior, and in the absence of extensive field observations could be used to determine whether an individual bear is likely to respond favorably to non-lethal management.
American black bears (Ursus americanus) historically inhabited every province and territory in Canada, all continental states in the United States (U.S.), and northern states of Mexico. We used BearsWhere?, an Internet mapping tool, to survey bear biologists in Canada, Mexico, and the U.S. and estimate the current range of black bears using 4 categories: primary range and secondary range (which together comprise total range), bear sighting locations outside range, and no bears reported. Primary and secondary ranges in 12 Canadian provinces and territories, 40 states in the U.S., and 6 states in Mexico totaled 10.5 million km2, representing 65–75% of the species' historical range. Total bear range in Canada was 6.9 million km2, representing 95–100% of its historical range. Prince Edward Island was the only province with no bear range or sightings. Total range in the U.S. was 3.5 million km2, representing 45–60% of U.S. historical range. Respondents reported occasional sightings but no primary or secondary range in 6 U.S. states (IA, KS, NE, ND, OH, and SD), and bears were absent from the District of Columbia and the remaining 4 states (DE, HI, IL, and IN). Only primary range data were available in Mexico, consisting of approximately 99,000 km2 across portions of 6 states (Chihuahua, Coahuila, Durango, Nuevo Leon, Sonora, and Tamaulipas). Our ability to detect a change in bear range was limited, but notable expansion of primary range since the mid-1990s was confirmed in Virginia and North Carolina.
The Alps–Dinaric–Pindos (ADP) bear population is considered to be one of the largest populations remaining in Europe. Despite its international importance for large-scale bear conservation, detailed and accurate information about the genetic and conservation status of some of its sub-populations is lacking. Serbia is located in the geographic center of the ADP bear population, and is of special importance because it connects this population to bear populations in southeastern Europe. Our aim was to establish a research protocol for genetic monitoring and provide information on genetic parameters of brown bears in western Serbia. From hair samples collected non-invasively from hair traps and 2 live-captures, we identified 10 individual bears; a comparison to other bear populations in Europe suggests a favorable genetic status (i.e., increased genetic diversity) of bears in this part of the country. The close geographic proximity of bears in western Serbia to bear populations in adjacent countries, and our results, suggest that the ADP population is interconnected in this region. We recommend a coordinated, multi-national approach for the monitoring and conservation of bears in southeastern Europe, for example, through the establishment of a common genetic database.
During the past century, habitat fragmentation and increased human impacts have reduced populations of large carnivores throughout the world. Although bears have been extirpated from human-dominated landscape in most parts of Europe, they still occur in multi-use cultural landscapes in Southern Transylvania, Romania. Wood-pastures—grazed permanent grasslands with scattered or clumped trees and shrubs—are important elements of these cultural landscapes and provide habitat for a wide range of species. However, wood-pastures are under threat from land-use change, including intensified agricultural use and land abandonment. In 2012 we assessed the level of activity of brown bears (Ursus arctos) and environmental factors influencing bear activity in 54 wood-pastures in Southern Transylvania. As an index of bear activity, we measured the proportion of anthills that were destroyed by bears. The variables were combined in 3 groups (anthropogenic effects, local variables, and landscape context) to test which group most strongly influenced bear activity. Bear activity was found in 47 (87%) wood-pastures. Bear activity was best explained by variables describing the landscape context, with proximity to the Carpathian Mountains, terrain ruggedness, and amount of surrounding woody vegetation positively related to bear activity. Local variables (distance to forest edge and anthill density) had no effect, and surprisingly, variables related to anthropogenic features (distance to major roads, distance to villages) were positively related to bear activity (albeit weakly). Most of the wood-pastures in Southern Transylvania were used by bears for foraging on ant larvae. For the conservation of brown bears in Southern Transylvania, it is important to maintain large areas of forest but also consider cultural landscape elements such as wood-pastures. To conserve European wood-pastures, we suggest they be explicitly considered in national nature conservation policies and in major European Union (EU) policies such as the EU Habitats Directive.
American black bears (Ursus americanus) were nearly extirpated from Missouri (USA) by the early 1900s and began re-colonizing apparent suitable habitat in southern Missouri following reintroduction efforts in Arkansas (USA) during the 1960s. We used anecdotal occurrence data from 1989 to 2010 and forest cover to describe broad patterns of black bear re-colonization, human–bear incidents, and bear mortality reports in Missouri. Overall, 1,114 black bear occurrences (including 118 with dependent young) were reported, with 95% occurring within the Ozark Highlands ecological region. We created evidentiary standards to increase reliability of reports, resulting in exclusion of 21% of all occurrences and 13% of dependent young. Human–bear incidents comprised 5% of total occurrences, with 86% involving bears eating anthropogenic foods. We found support for a northward trend in latitudinal extent of total occurrences over time, but not for reported incidents. We found a positive correlation between the distribution of bear occurrences and incidents. Twenty bear mortalities were reported, with 60% caused by vehicle collisions. Black bear occurrences have been reported throughout most of Missouri's forested areas, although most reports of reproduction occur in the southern and eastern Ozark Highlands. Though occurrence data are often suspect, the distribution of reliable reports supports our understanding of black bear ecology in Missouri and reveals basic, but important, large-scale patterns important for establishing management and research plans.
Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE) are opportunistic omnivores that eat a great diversity of plant and animal species. Changes in climate may affect regional vegetation, hydrology, insects, and fire regimes, likely influencing the abundance, range, and elevational distribution of the plants and animals consumed by GYE grizzly bears. Determining the dietary breadth of grizzly bears is important to document future changes in food resources and how those changes may affect the nutritional ecology of grizzlies. However, no synthesis exists of all foods consumed by grizzly bears in the GYE. We conducted a review of available literature and compiled a list of species consumed by grizzly bears in the GYE. We documented ≥266 species within 200 genera from 4 kingdoms, including 175 plant, 37 invertebrate, 34 mammal, 7 fungi, 7 bird, 4 fish, 1 amphibian, and 1 algae species as well as 1 soil type consumed by grizzly bears. The average energy values of the ungulates (6.8 kcal/g), trout (Oncorhynchus spp., 6.1 kcal/g), and small mammals (4.5 kcal/g) eaten by grizzlies were higher than those of the plants (3.0 kcal/g) and invertebrates (2.7 kcal/g) they consumed. The most frequently detected diet items were graminoids, ants (Formicidae), whitebark pine seeds (Pinus albicaulis), clover (Trifolium spp.), and dandelion (Taraxacum spp.). The most consistently used foods on a temporal basis were graminoids, ants, whitebark pine seeds, clover, elk (Cervus elaphus), thistle (Cirsium spp.), and horsetail (Equisetum spp.). Historically, garbage was a significant diet item for grizzlies until refuse dumps were closed. Use of forbs increased after garbage was no longer readily available. The list of foods we compiled will help managers of grizzly bears and their habitat document future changes in grizzly bear food habits and how bears respond to changing food resources.
Barcoding DNA is an accepted tool in taxonomic identification. We report the design of a universal primer pair for polymerase chain reaction (PCR) amplification of the cytochrome c oxidase subunit I gene (COI) developed using COI gene sequences of all 8 extant bear species (family Ursidae) available on GenBank. This primer pair successfully amplified approximately 700 base pairs of the COI gene of Asiatic black (Ursus thibetanus; n = 12) and Himalayan brown (U. arctos; n = 6) bears. We sequenced the PCR product and compared the sequences with those of the other 6 species to generate degrees of homology (83–92%) and genetic distances. The primer pair has yet to be tested in the other 6 species. We developed a preliminary phylogenetic tree for the 8 species based on these data.
Optimization of DNA extraction and amplification techniques increases the reliability of genetic studies used to estimate population size and assess genetic diversity, particularly for non-invasively collected samples. We evaluated the effectiveness of 4 DNA extraction procedures—the Roboscreen and Qiagen kit methods and the Organic and Chelex methods, as applied to invasively and non-invasively collected samples from Asiatic black bears (Ursus thibetanus). We assessed effectiveness based on quantity and purity of the extracts by method, and their ability to amplify genomic DNA via polymerase chain reaction (PCR) amplification of a single simple sequence repeat (SSR) marker. For each method, the greatest average DNA quantity and purity index (86.25%) was from blood, while muscle showed greatest DNA quantity and purity index using the Qiagen DNA extraction method. The Roboscreen kit and Chelex method provided a 57% and 58% PCR success rate, respectively, for hairs, demonstrating the value of such samples for molecular studies of Asiatic black bears.