RESUMEN

One of the most obvious impacts of roads is roadkill, a problem that is recently being addressed in Mexico. However, there are economic and human resource limitations to monitor the entire road network, assess its impacts, and propose mitigation measures. The black bear (Ursus americanus) is a top predator and the largest terrestrial mammal distributed in Mexico, currently the only of the Ursidae family. In recent years, its presence near human settlements and incidents on roads has increased. We generated a single MaxEnt model to identify characteristics of sites with high black bear roadkill risk and to identify these areas within protected natural areas. We obtained 83 bear roadkill records between 2008 and 2022, and we used a set of 16 variables that included landscape, road variables, and human variables. The model had an area under curve value of 0.96 indicating good performance and the Jacknife analysis identified influence on the roadkill risk of the distance to water bodies, protected areas, scrubland, drainages, and speed limit. We identified 3883.25 km of roads at high roadkill risk for black bears of which, 373.10 (9.6%) km were inside protected areas. We suggest placing speed bumps and effective signage on high-risk sections as a short-term, low-cost strategy. The results help to focus conservation efforts to specific sections of the road network, as roadkill is an increasing source of mortality that has not been evaluated for black bear in Mexico. This information is applicable for mitigating the impacts of existing roads and for planning new projects that have less impact on wild black bear populations and, at the same time, increase the safety of vehicle drivers.

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RESUMEN

Asiatic black bear is present in variety of habitats like broad-leaves and coniferous forests, extending form sea level to 4300m elevation and change their habitat for food purpose seasonally. The present study was conducted at Kaghan and Siran Valleys, District Mansehra, Khyber Pakhtunkhwa, Pakistan to assess habitat of black bear. Line transect method was used for observation of bear signs. Twelve meter circular radius plots were selected for the concern vegetations i.e. (trees, shrubs and herbs) and three to six plots were placed in each transect. At the result of sign survey, thirteen different categories of bear signs were recorded and encounter rate was calculated for each sign. A total of 1858 signs were observed during field surveys. Total (81%) coniferous species were recoded among trees, with the highest appearance of Pinus wallichiana (34.22%) and Spruce spp (27.76%), similarly broad leaves trees (18.56%) were also recoded from habitat plots. Most of the signs were encountered in bushy areas, whereas high number of Viburnum Spp (60.29%) was present. It is indicated that black bear prefers blend of Coniferous Trees, Viburnum and Ferns Species; probably because these plants provide enough food, protection, and meticulous shelter because more than 80% of habitat composed of these three species. Currently habitat destruction and increase in human population are the up-growing issues for wild animals (especially Asiatic black bear), which is highly sensitive to such problems. High levels of conservation efforts are recommended for the protection of black bear habitat and to avoid human interference in their territory.(AU)

O urso-negro asiático está presente em uma variedade de habitats, como folhas largas e florestas de coníferas, estendendo-se do nível do mar até 4.300 m de altitude e mudando seu habitat para fins alimentares sazonalmente. O presente estudo foi conduzido nos vales Kaghan e Siran, distrito de Mansehra, Khyber Pakhtunkhwa, Paquistão, para avaliar o habitat do urso preto. O método de transecto linear foi usado para a observação de sinais do urso. Parcelas de raio circular de 12 m foram selecionadas para a vegetação de preocupação, ou seja, árvores, arbustos e ervas, e 3 a 6 parcelas foram colocadas em cada transecto. No resultado da pesquisa de sinais, 13 categorias diferentes de sinais de urso foram registradas e a taxa de encontro foi calculada para cada sinal. Um total de 1858 sinais foi observado durante os levantamentos de campo. O total (81%) de espécies de coníferas foi recodificado entre as árvores, com maior aparecimento de Pinus wallichiana (34,22%) e Spruce spp (27,76%); árvores de folhas largas (18,56%) também foram recodificadas em parcelas de habitat. A maioria dos sinais foi encontrada em áreas com arbustos, enquanto um alto número de Viburnum spp (60,29%) estava presente. É indicado que o urso-negro prefere a mistura de árvores coníferas, espécies de viburnos e samambaias; provavelmente porque essas plantas fornecem alimento suficiente, proteção e abrigo meticuloso porque mais de 80% do habitat é composto por essas três espécies. Atualmente, a destruição do habitat e o aumento da população humana são questões crescentes para os animais selvagens, especialmente o urso-negro asiático, que é altamente sensível a esses problemas. Altos níveis de esforços de conservação são recomendados para a proteção do habitat do urso-negro e para evitar a interferência humana em seu território.(AU)

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RESUMEN

Asiatic black bear is present in variety of habitats like broad-leaves and coniferous forests, extending form sea level to 4300m elevation and change their habitat for food purpose seasonally. The present study was conducted at Kaghan and Siran Valleys, District Mansehra, Khyber Pakhtunkhwa, Pakistan to assess habitat of black bear. Line transect method was used for observation of bear signs. Twelve meter circular radius plots were selected for the concern vegetation’s i.e. (trees, shrubs and herbs) and three to six plots were placed in each transect. At the result of sign survey, thirteen different categories of bear signs were recorded and encounter rate was calculated for each sign. A total of 1858 signs were observed during field surveys. Total (81%) coniferous species were recoded among trees, with the highest appearance of Pinus wallichiana (34.22%) and Spruce spp (27.76%), similarly broad leaves trees (18.56%) were also recoded from habitat plots. Most of the signs were encountered in bushy areas, whereas high number of Viburnum Spp (60.29%) was present. It is indicated that black bear prefers blend of Coniferous Trees, Viburnum and Ferns Species; probably because these plants provide enough food, protection, and meticulous shelter because more than 80% of habitat composed of these three species. Currently habitat destruction and increase in human population are the up-growing issues for wild animals (especially Asiatic black bear), which is highly sensitive to such problems. High levels of conservation efforts are recommended for the protection of black bear habitat and to avoid human interference in their territory.

O urso-negro asiático está presente em uma variedade de habitats, como folhas largas e florestas de coníferas, estendendo-se do nível do mar até 4.300 m de altitude e mudando seu habitat para fins alimentares sazonalmente. O presente estudo foi conduzido nos vales Kaghan e Siran, distrito de Mansehra, Khyber Pakhtunkhwa, Paquistão, para avaliar o habitat do urso preto. O método de transecto linear foi usado para a observação de sinais do urso. Parcelas de raio circular de 12 m foram selecionadas para a vegetação de preocupação, ou seja, árvores, arbustos e ervas, e 3 a 6 parcelas foram colocadas em cada transecto. No resultado da pesquisa de sinais, 13 categorias diferentes de sinais de urso foram registradas e a taxa de encontro foi calculada para cada sinal. Um total de 1858 sinais foi observado durante os levantamentos de campo. O total (81%) de espécies de coníferas foi recodificado entre as árvores, com maior aparecimento de Pinus wallichiana (34,22%) e Spruce spp (27,76%); árvores de folhas largas (18,56%) também foram recodificadas em parcelas de habitat. A maioria dos sinais foi encontrada em áreas com arbustos, enquanto um alto número de Viburnum spp (60,29%) estava presente. É indicado que o urso-negro prefere a mistura de árvores coníferas, espécies de viburnos e samambaias; provavelmente porque essas plantas fornecem alimento suficiente, proteção e abrigo meticuloso porque mais de 80% do habitat é composto por essas três espécies. Atualmente, a destruição do habitat e o aumento da população humana são questões crescentes para os animais selvagens, especialmente o urso-negro asiático, que é altamente sensível a esses problemas. Altos níveis de esforços de conservação são recomendados para a proteção do habitat do urso-negro e para evitar a interferência humana em seu território.

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RESUMEN

Abstract Asiatic black bear is present in variety of habitats like broad-leaves and coniferous forests, extending form sea level to 4300m elevation and change their habitat for food purpose seasonally. The present study was conducted at Kaghan and Siran Valleys, District Mansehra, Khyber Pakhtunkhwa, Pakistan to assess habitat of black bear. Line transect method was used for observation of bear signs. Twelve meter circular radius plots were selected for the concern vegetations i.e. (trees, shrubs and herbs) and three to six plots were placed in each transect. At the result of sign survey, thirteen different categories of bear signs were recorded and encounter rate was calculated for each sign. A total of 1858 signs were observed during field surveys. Total (81%) coniferous species were recoded among trees, with the highest appearance of Pinus wallichiana (34.22%) and Spruce spp (27.76%), similarly broad leaves trees (18.56%) were also recoded from habitat plots. Most of the signs were encountered in bushy areas, whereas high number of Viburnum Spp (60.29%) was present. It is indicated that black bear prefers blend of Coniferous Trees, Viburnum and Ferns Species; probably because these plants provide enough food, protection, and meticulous shelter because more than 80% of habitat composed of these three species. Currently habitat destruction and increase in human population are the up-growing issues for wild animals (especially Asiatic black bear), which is highly sensitive to such problems. High levels of conservation efforts are recommended for the protection of black bear habitat and to avoid human interference in their territory.

Resumo O urso-negro asiático está presente em uma variedade de habitats, como folhas largas e florestas de coníferas, estendendo-se do nível do mar até 4.300 m de altitude e mudando seu habitat para fins alimentares sazonalmente. O presente estudo foi conduzido nos vales Kaghan e Siran, distrito de Mansehra, Khyber Pakhtunkhwa, Paquistão, para avaliar o habitat do urso preto. O método de transecto linear foi usado para a observação de sinais do urso. Parcelas de raio circular de 12 m foram selecionadas para a vegetação de preocupação, ou seja, árvores, arbustos e ervas, e 3 a 6 parcelas foram colocadas em cada transecto. No resultado da pesquisa de sinais, 13 categorias diferentes de sinais de urso foram registradas e a taxa de encontro foi calculada para cada sinal. Um total de 1858 sinais foi observado durante os levantamentos de campo. O total (81%) de espécies de coníferas foi recodificado entre as árvores, com maior aparecimento de Pinus wallichiana (34,22%) e Spruce spp (27,76%); árvores de folhas largas (18,56%) também foram recodificadas em parcelas de habitat. A maioria dos sinais foi encontrada em áreas com arbustos, enquanto um alto número de Viburnum spp (60,29%) estava presente. É indicado que o urso-negro prefere a mistura de árvores coníferas, espécies de viburnos e samambaias; provavelmente porque essas plantas fornecem alimento suficiente, proteção e abrigo meticuloso porque mais de 80% do habitat é composto por essas três espécies. Atualmente, a destruição do habitat e o aumento da população humana são questões crescentes para os animais selvagens, especialmente o urso-negro asiático, que é altamente sensível a esses problemas. Altos níveis de esforços de conservação são recomendados para a proteção do habitat do urso-negro e para evitar a interferência humana em seu território.

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The phylogeography of the American black bear (Ursus americanus) is characterized by isolation into glacial refugia, followed by population expansion and genetic admixture. Anthropogenic activities, including overharvest, habitat loss, and transportation infrastructure, have also influenced their landscape genetic structure. We describe the genetic structure of the American black bear in the American Southwest and northern Mexico and investigate how prehistoric and contemporary forces shaped genetic structure and influenced gene flow. Using a suite of microsatellites and a sample of 550 bears, we identified 14 subpopulations organized hierarchically following the distribution of ecoregions and mountain ranges containing black bear habitat. The pattern of subdivision we observed is more likely a product of postglacial habitat fragmentation during the Pleistocene and Holocene, rather than a consequence of contemporary anthropogenic barriers to movement during the Anthropocene. We used linear mixed-effects models to quantify the relationship between landscape resistance and genetic distance among individuals, which indicated that both isolation by resistance and geographic distance govern gene flow. Gene flow was highest among subpopulations occupying large tracts of contiguous habitat, was reduced among subpopulations in the Madrean Sky Island Archipelago, where montane habitat exists within a lowland matrix of arid lands, and was essentially nonexistent between two isolated subpopulations. We found significant asymmetric gene flow supporting the hypothesis that bears expanded northward from a Pleistocene refugium located in the American Southwest and northern Mexico and that major highways were not yet affecting gene flow. The potential vulnerability of the species to climate change, transportation infrastructure, and the US-Mexico border wall highlights conservation challenges and opportunities for binational collaboration.

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Mange, a parasitic skin disease caused by various species of mites, is found in free-ranging wildlife populations and has been increasingly reported in American black bears (Ursus americanus) over the last decade in New York State (NYS), USA. Our goal was to describe the geographic, seasonal, and demographic factors associated with mange in this species in NYS. Our retrospective study used historic, opportunistic data from diagnostic necropsy records and visual sighting reports collected by the NYS Wildlife Health Program from 2009 to 2018. We used chi-square tests for independence and odds ratios to examine whether geographic location, year, season, sex, age, and reason for laboratory submission were associated with mange in bears. We used maps and seasonal analysis to investigate emerging patterns. We confirmed increased black bear mange reports in recent years. Necropsy data revealed more bears submitted to the laboratory because of mange, mainly caused by Sarcoptes scabiei; females were more likely than males to present with sarcoptic mange. We found that cases of mange in the Northern Zone were widely disseminated throughout the region, whereas cases in the Southern Zone were concentrated in two areas along the Pennsylvania border. Seasonally, mange cases showed peaks occurring in late spring to early summer and in fall. Our results were on the basis of available data; a comprehensive statewide surveillance program would be useful to better understand the apparent increase in mange and its potential impact on both the welfare of individual animals and the population of black bears in NYS. Additional research on the timing of transmission dynamics associated with females in winter dens may be helpful to wildlife managers to identify strategies to mitigate deleterious spread of the disease in black bears.

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Informed management of American black bears (Ursus americanus) requires knowledge of the distribution and pathology of diseases affecting the species. Little information is available on pathogen prevalence from black bear populations in the Southwest, US, and it is unknown how these infections may influence black bear populations or disease transmission. We captured New Mexico black bears (Ursus americanus amblyceps) during 2016-17 as part of a long-term monitoring project and opportunistically collected 36 blood samples from 12 female and 17 male black bears. We wanted to determine prior exposure to canine distemper virus, canine parvovirus, Yersinia pestis, Francisella tularensis, West Nile virus, Toxoplasma gondii, and the tick-borne pathogens, Anaplasma spp., Ehrlichia spp., Borrelia burgdorferi, Rickettsia spp., and Babesia spp. Approximately half (55%, 16/29) of the individuals sampled had antibodies to Y. pestis, and 37% (10/27) had antibodies to T. gondii. Prevalence of antibodies to West Nile virus, F. tularensis, and canine parvovirus were lower (i.e., 11, 10, and 3%, respectively). We detected no antibodies to canine distemper, B. burgdorferi, Rickettsia spp., or Babesia spp. We documented changes in antibody titer levels for both sexes of several recaptured black bears. Our data will inform managers of pathogen prevalence and distribution in black bears in north-central New Mexico and provide a vital baseline dataset for future pathogen monitoring. Additionally, these data support actions to minimize exposure through handling wild individuals or through hunter harvest activities.

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