Ursus最新文献

{"title":"Effects of a highway on the genetic diversity of Asiatic black bears","authors":"Sakawrat Vaeokhaw, D. Ngoprasert, A. Swatdipong, G. Gale, Worata Klinsawat, T. Vichitsoonthonkul","doi":"10.2192/URSUS-D-18-00013.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00013.2","url":null,"abstract":"Abstract: Bears are globally threatened by habitat fragmentation, particularly due to roads, which can act as dispersal barriers. We used noninvasive hair sampling to study the genetic diversity of Asiatic black bears (Ursus thibetanus) in the Dong Phayayen–Khao Yai forest complex, Thailand, during 2012–2015. We used 9 microsatellite loci to investigate black bears inhabiting 2 sides of the complex that have been separated by a highway for 60 years. We genetically identified 49 individuals (31 males and 18 females) in Khao Yai and 45 individuals (25 males and 20 females) in Dong Phayayen. The genetic diversity level of Dong Phayayen was similar to Khao Yai; low differentiation (F ST = 0.035) and no strong evidence of inbreeding was indicated for both populations (FIS = 0.13 and 0.07, respectively). However, the pairwise FST between Khao Yai and Dong Phayayen was notably higher (FST = 0.035 and 0.038, respectively) than within Dong Phayayen (0.004), suggesting an observable effect of the highway on the populations, with a current migration rate of 1% between the 2 forests. Thus, the road apparently acts as a significant dispersal barrier for the black bear. This population is of conservation concern because the estimated effective population size (Ne = 178 bears) was below the recommended size for black bears. The relatively long generation time of Asiatic black bears could be the main factor contributing to the time lag between placement of the highway and changes in genetic diversity between the populations. Our simulations indicated a strong negative impact of the highway on the genetics of this population within the next 10 generations and an increased risk of extinction if there is continued isolation. Our data also suggest that an assisted migration program via habitat corridors could reduce the impact of this highway and promote the persistence of bears.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91013577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Female brown bears use areas with infanticide risk in a spatially confined population","authors":"V. Penteriani, A. Zarzo‐Arias, María del Mar Delgado, Fredrick Dalerum, E. Gurarie, Paloma Peón Torre, Teresa Sánchez Corominas, V. M. Vázquez, Pablo Vázquez García, A. Ordiz","doi":"10.2192/URSUS-D-18-00019R4","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00019R4","url":null,"abstract":"Abstract: Areas used by female brown bears (Ursus arctos) with cubs-of-the-year (hereafter, FCOY) during the first months after den exit are crucial for offspring survival, primarily because of the risk of infanticide by male bears. Therefore, FCOY may avoid areas frequented by adult males during the mating season. The main aim of this study was to identify landscape features (i.e., structure, composition, and human footprint) that may differentiate the habitat use of FCOY in the small bear population of the Cantabrian Mountains (northwestern Spain; 2001–2016) from (a) areas frequented by females with yearlings, because older cubs are at less risk of infanticide than cubs-of-the-year, and (b) bear mating areas (i.e., the riskiest areas for FCOY because of the presence of adult males). During the first months after den emergence (Apr–Jun), FCOY settled in the roughest areas of the Cantabrian Mountains at most spatial scales. This settlement pattern might represent a behavioral adaptation of FCOY to reduce the risk of encounters with males during the mating season. However, FCOY also settled in similar landscapes to those used by adult bears during the mating season, which may increase the likelihood of risky encounters. Indeed, we observed a spatial overlap between observed locations of FCOY and mating areas, which may help explain the high frequency of infanticide observed in the Cantabrian Mountains. We hypothesize that the need for both shelter and food in early spring may ‘trap’ FCOY in otherwise favorable areas that overlap with mating areas. This may occur predominately in small and confined bear populations, such as the one in the Cantabrian Mountains, where a restricted range and limited habitat availability might prevent FCOY from avoiding risky areas successfully.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73510944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"American black bear population fragmentation detected with pedigrees in the transborder Canada–United States region","authors":"M. Proctor, W. Kasworm, J. Teisberg, Christopher Servheen, Thomas G. Radandt, C. Lamb, K. Kendall, R. Mace, D. Paetkau, M. Boyce","doi":"10.2192/URSUS-D-18-00003R2","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00003R2","url":null,"abstract":"Abstract: Population fragmentation is stressing wildlife species worldwide. In populations with minimal genetic structure across potential fractures, detecting fragmentation can be challenging. Here we apply a relatively unused approach, genetic pedigree analysis, to detect fragmentation in the American black bear (Ursus americanus) across 2 highway corridors that are bordered by large, contiguous populations. We compared our results with movements detected through Global Positioning System (GPS) telemetry of collared bears between 2005 and 2010. We used 20-locus microsatellite genotypes to identify 104 first-order relatives (parent–offspring or full siblings) within 383 black bears, sampled between 2002 and 2012. We compared numbers of pairs of immediate relatives found on either side of 2 highways—U.S. Highway 2 in northwestern Montana, USA, and BC Highway 3 in southeastern British Columbia, Canada—with an expected rate, the mean across 22 lines parallel to each highway at 1-km intervals. We found that over similar geographic scales, dispersal was lower across the transportation corridors than adjacent areas without a highway corridor. The observed number of migrants across Highway 2 was 3, well below the confidence interval of the expected number of 15.1 migrants/available bears (95% CI = 12.2–18.0). Highway 3 had 6 migrants, compared with the expected 13.1 bears (95% CI = 10.8–15.5). None of 16 black bears wearing GPS radiocollars for 1 year crossed Highway 2, yet 6 of 18 crossed Highway 3. These results suggest that even though 33% of radiocollared black bears crossed Highway 3, there appeared to be less dispersal across the transportation corridors than across other regions in the study area. Pedigree and telemetry results were more closely aligned in the Highway 2 system, with both methods suggesting more intense fragmentation than we found along Highway 3. Our results identified pedigree analysis as another tool for investigating population fragmentation, particularly in situations where genetic differentiation is too weak to determine migration rates using individual-based methods, such as population assignment.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81099823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assimilated diet patterns of American black bears in the Sierra Nevada and western Great Basin, Nevada, USA","authors":"Jennapher Teunissen van Manen, C. Lackey, J. Beckmann, L. Muller, Zheng-hua Li","doi":"10.2192/URSUS-D-17-00031.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-17-00031.2","url":null,"abstract":"Abstract: In western Nevada, USA, the American black bear (Ursus americanus) coexists with humans and increasing urban sprawl. Hotels, casinos, restaurants, and homeowners dispose large quantities of high-protein, calorie-rich foods, often in unsecured waste containers. We used 173 hair samples from black bears captured in western Nevada from 2003 to 2010 and conducted δ13C and δ15N analysis to examine anthropogenic food use. We developed a set of a priori models to examine the effect of biological (sex, age class, mass category [considering sex and age]), chronological (season, molt phase, and year), and spatial (urban–wildland classification [UW class]) factors potentially affecting use of anthropogenic foods and accompanying stable isotope signatures. Bears in above-average mass categories had enriched 13C and 15N signatures compared with bears of below-average mass. Wildland bears had depleted 13C compared with urban bears and appeared to use human foods less. Postmolt hair samples (representing late-spring–early summer diet) were depleted in both 13C and 15N relative to premolt hairs (late-summer–autumn diet), indicating changes in food availability. Male black bears had enriched 15N compared with females, indicating more meat in their diet. Our results indicated substantial 13C and 15N enrichment of black bear diets in Nevada, which was affected by biological, chronological, and spatial factors. Using mixing models of the 2 isotopes, we found both urban and wildland bears relied on natural and anthropogenic foods, with wildland bears using wild foods more often. There was only 3.8% difference in the median use of human foods between urban and wildland bears, but great variability for individual bears in each location category. Our results affirmed that, to effectively address human–bear conflicts, officials should emphasize exclusion of anthropogenic food attractants on a year-round basis and further try to understand factors affecting individual bear use of garbage.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80203529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of roads and motorized human access on grizzly bear populations in British Columbia and Alberta, Canada","authors":"M. Proctor, B. Mclellan, G. Stenhouse, G. Mowat, C. Lamb, M. Boyce","doi":"10.2192/URSUS-D-18-00016.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00016.2","url":null,"abstract":"Abstract: The growing human footprint has placed unprecedented stressors on ecosystems in recent decades resulting in losses of biodiversity and ecosystem function around the world. Roads are influential through their direct footprint and facilitating human access; however, their influence can be mitigated. Here, we review the scientific literature on the relationship between grizzly bears (Ursus arctos), human motorized access, and the efficacy of motorized access control as a tool to benefit grizzly bear conservation in western Canada. We found that motorized access affected grizzly bears at the individual and population levels through effects on bears' habitat use, home range selection, movements, population fragmentation, survival, and reproductive rates that ultimately were reflected in population density, trend, and conservation status. Motorized access management was effective in mitigating these effects. Our review of the scientific literature suggests that industrial road management would be a useful tool if (a) roads exist in high-quality grizzly bear habitats with population-energy-rich food resources; (b) open road densities exceed 0.6 km/km2; (c) less than at least 60% of the unit's area is >500 m from an open road in patch sizes of ≥10 km2. Motorized access management would be most beneficial in threatened populations, in areas where roads occur in the highest quality habitats, within and adjacent to identified linkage areas between population units, and in areas that are expected to exceed motorized route thresholds as a result of resource extraction activities. Evidence suggests benefits of motorized access management are more likely to be realized if habitat quality is integrated and is best if managed at scales that optimize the benefit of distribution, survival, reproduction, and density of female grizzly bears. We encourage land use managers developing access rules to consider a wider spectrum of biodiversity and overall habitat conservation, and suggest landscape road targets that will benefit bear conservation.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78856466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primarily resident grizzly bears respond to late-season elk harvest","authors":"Frank T. van Manen, M. Ebinger, D. Gustine, M. Haroldson, Katharine R. Wilmot, Craig Whitman","doi":"10.2192/URSUS-D-18-00018R2","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00018R2","url":null,"abstract":"Abstract: Autumn ungulate hunting in the Greater Yellowstone Ecosystem carries the risk of hunter–grizzly bear (Ursus arctos) conflict and creates a substantial challenge for managers. For Grand Teton National Park, Wyoming, USA, a key information need is whether increased availability of elk (Cervus canadensis) carcasses during a late autumn (Nov–Dec) harvest within the national park attracts grizzly bears and increases the potential for conflict with hunters. Using a robust design analysis with 6 primary sampling periods during 2014–2015, we tested the hypothesis that the elk harvest resulted in temporary movements of grizzly bears into the hunt areas, thus increasing bear numbers. We detected 31 unique individuals (6 F, 25 M) through genetic sampling and retained 26 encounter histories for analysis. Markovian movement models had more support than a null model of no temporary movement. Contrary to our research hypothesis, temporary movements into the study area occurred between the July–August (no hunt; N̄2014–2015 = 5) and September–October (no hunt; N̄2014–2015 = 24) primary periods each year, rather than during the transition from September–October (no hunt) to November–December (hunt; N̄2014–2015 = 15). A post hoc analysis indicated that September–October population estimates were biased high by detections of transient bears. Grizzly bear presence during the elk hunt was limited to approximately 15 resident bears that specialized in accessing elk carcasses. The late timing of the elk hunt likely moderated the effect of carcasses as a food attractant because it coincides with the onset of hibernation. From a population response perspective, the current timing of the elk harvest likely represents a scenario of low relative risk of hunter–bear conflicts. The risk of hunter–grizzly bear encounters remains, but may be more a function of factors that operate at the level of individual bears and hunters, such as hunter movements and bear responses to olfactory cues.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82213302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large carnivores as potential predators of sun bears","authors":"Hla Naing, Saw Htun, J. Kamler, D. Burnham, D. Macdonald","doi":"10.2192/URSU-D-18-0022.2","DOIUrl":"https://doi.org/10.2192/URSU-D-18-0022.2","url":null,"abstract":"Abstract: Sun bears (Helarctos malayanus) have a wide distribution in Southeast Asia, but little is known about their natural predators. During a camera-trap survey in 2018 in Htamanthi Wildlife Sanctuary, Myanmar, we photographed a male leopard (Panthera pardus) carrying a sun bear cub by the throat. This is the first reported case of probable predation on sun bears by leopards, and only their second confirmed predator. A literature review showed that consumption of sun bears and Asiatic black bears (Ursus thibetanus) by tigers (P. tigris) was widespread in Southeast Asia, whereas consumption of both bear species by leopards and dholes (Cuon alpinus) was less common. Outside of Southeast Asia, tigers and leopards, but not dholes, were shown to kill or consume other bear species. Future research should examine interspecific relationships between sun bears and large felids to better understand what, if any, impacts large felids have on sun bear ecology.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81212256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Movement and activity of reintroduced giant pandas","authors":"Ke He, Q. Dai, Andrew P. Foss-Grant, E. Gurarie, W. Fagan, M. Lewis, Jing Qing, F. Huang, Xuyu Yang, X. Gu, Yan Huang, He-min Zhang, Desheng Li, Xiao Zhou, Zhisong Yang","doi":"10.2192/URSUS-D-17-00030.1","DOIUrl":"https://doi.org/10.2192/URSUS-D-17-00030.1","url":null,"abstract":"Abstract: Wild populations of giant pandas (Ailuropoda melanoleuca) have steadily increased in the past 2 decades, but the species' distribution remains highly fragmented. Since 2009, an introduction program has worked to rescue the giant panda population of Liziping National Nature Reserve in southwestern Sichuan Province, China. Using Global Positioning System and activity collar data collected between May 2011 and March 2016, we investigated the post-release behavior of the first 5 pandas introduced to Liziping, 4 of which were bred in captivity. Using a change-point analysis, we tested several models of post-release adjustment to the habitat. We found that it took 3–4 months for captive-bred individuals to exhibit movement patterns characteristic of their long-term behavior. Furthermore, we found that, for these individuals, post-adjustment behavior varied by season, with activity levels peaking between May and July, a period of high resource availability. This also corresponded with a decrease in large movement events, where individuals were less likely to travel long distances quickly during these months. Unlike wild giant pandas in more northerly reserves, the 5 pandas released in Liziping (both captive-bred and translocated) did not exhibit any seasonal migration between elevations. Finally, we found that our study individuals had 2 daily periods of activity, which was comparable to those reported in the literature for wild individuals. Our results suggest that captive-bred giant pandas are able to successfully adjust to the wild and, after a period of adjustment, settle into long-term behavior patterns.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78022741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Demographics of American black bear populations following changes in harvest policy","authors":"Thea V. Kristensen, Myron Means, L. Eggert, Kimberly G. Smith, D. White","doi":"10.2192/URSUS-D-18-00002.1","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00002.1","url":null,"abstract":"Abstract: Harvest can affect the size and composition of wildlife populations. American black bear (Ursus americanus) populations in the Central Interior Highlands, Arkansas, USA, were nearly extirpated as a result of harvest and habitat change, but have expanded geographically and demographically since reintroduction in the late 1950s and early 1960s. Harvest levels have increased since baiting was permitted on private land in 2001; therefore, we initiated demographic analyses of 2 black bear populations to evaluate the effect of this policy change. We evaluated composition of harvest in response to baiting and used noninvasive genetic sampling in conjunction with capture–recapture methods to estimate density, survival, and population growth rate (λ) of black bear populations at locations within the Ouachita (2006–2008) and Ozark (2009–2011) national forests, Arkansas. More males were harvested than females with the use of bait. Capture probability varied annually; thus, multi-year data were valuable for capturing accurate population parameters. Density was approximately 14 bears/100 km2 in the Ouachitas and approximately 26/100 km2 for the Ozarks, which was greater than estimates from historical data (1989–1990). Thus, these populations maintained or exceeded previous density estimates while the use of bait was allowed on private land. However, as with any harvested population, it will be important to continue to monitor the population to be able make decisions about appropriate harvest policies going forward.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73925015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Population genetics of American black bears in Georgia, USA","authors":"Michael J. Hooker, B. Bond, Michael J. Chamberlain","doi":"10.2192/URSUS-D-18-00025.1","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00025.1","url":null,"abstract":"Abstract: There are 3 American black bear (Ursus americanus) populations in the state of Georgia, USA. We used multi-locus microsatellite genotypes derived from bear hair and tissue samples collected across these populations to assess levels of genetic diversity within and between populations. We used population assignment clustering to evaluate whether there has been recent immigration into the smallest of the 3 populations, the Central Georgia Bear Population. Compared with other bear populations in the United States, the North Georgia and South Georgia Bear Populations have relatively high rates of genetic diversity (Ho = 0.72 ± 0.02, A = 6.68 ± 0.32, and Ho = 0.72 ± 0.02, A = 6.82 ± 0.35, respectively). In contrast, the Central Georgia Bear Population has relatively low rates (Ho = 0.46 ± 0.03, and A = 3.96 ± 0.20). Fixation indices for pairings between Georgia bear populations indicated that the North Georgia Bear Population was more similar to the South Georgia Bear Population than either was to the Central Georgia Bear Population. Our findings suggest that the Central Georgia Bear population has experienced long-term genetic isolation and genetic drift. Of a sample of 365 bears from Central Georgia, we only detected 1 immigrant and no evidence of gene flow into the population. We recommend development and implementation of plans to encourage gene flow toward the Central Georgia Bear Population.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78572898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}