Pub Date : 2023-05-15DOI: 10.2192/URSUS-D-22-00003R1
Melissa J Reynolds-Hogland, Alan B. Ramsey, C. Muench, Kirsten Terkildsen, K. Pilgrim, Cory Engkjer, Philip W. Ramsey
Abstract: Animal tool use has been documented for a variety of wildlife, but few studies have evaluated tool use by bears. We used long-term video data to observe and classify behaviors of wild American black bears (Ursus americanus) in western Montana, USA, during 2012–2022. We present video-documentation of true and borderline tool use by multiple individuals. Six bears (4F:2M) picked up sticks from the bottom of a creek pool and then manipulated the sticks with their forepaws to scratch and/or rub themselves. In addition, one bear manipulated a tree sapling near a cage trap in an apparent attempt to reach hanging food. We identified several parent–offspring relationships among our small sample size of tool users, indicating that tool use behavior may have partially developed via social learning and/or genetic inheritance. Our findings build on the limited research on ursid tool use and demonstrate the value of long-term video data to document wild bear behavior.
{"title":"Video-documentation of true and borderline tool use by wild American black bears","authors":"Melissa J Reynolds-Hogland, Alan B. Ramsey, C. Muench, Kirsten Terkildsen, K. Pilgrim, Cory Engkjer, Philip W. Ramsey","doi":"10.2192/URSUS-D-22-00003R1","DOIUrl":"https://doi.org/10.2192/URSUS-D-22-00003R1","url":null,"abstract":"Abstract: Animal tool use has been documented for a variety of wildlife, but few studies have evaluated tool use by bears. We used long-term video data to observe and classify behaviors of wild American black bears (Ursus americanus) in western Montana, USA, during 2012–2022. We present video-documentation of true and borderline tool use by multiple individuals. Six bears (4F:2M) picked up sticks from the bottom of a creek pool and then manipulated the sticks with their forepaws to scratch and/or rub themselves. In addition, one bear manipulated a tree sapling near a cage trap in an apparent attempt to reach hanging food. We identified several parent–offspring relationships among our small sample size of tool users, indicating that tool use behavior may have partially developed via social learning and/or genetic inheritance. Our findings build on the limited research on ursid tool use and demonstrate the value of long-term video data to document wild bear behavior.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"148 1","pages":"1 - 12"},"PeriodicalIF":1.3,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74756338","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}
Pub Date : 2023-01-24DOI: 10.2192/URSUS-D-22-00015
V. Penteriani, Alfonso Hartasánchez, Juan Díaz García, José Ramón Magadan Ruitiña, María del Mar Delgado
Abstract: Patches of color may be used to communicate to conspecifics, mainly in species showing uniform coloration, and may (a) help individuals maintain visual contact, such as between mothers and their young; (b) function as signals of subordination or to frighten rivals; (c) warn conspecifics of approaching predators; and/or (d) signal reproductive condition, health, or genetic quality to potential mates. Intraspecific communication represents one of the major evolutionary forces responsible for the coloration of body parts, but the meaning of many of these signals is still unclear. One of the first steps to understanding whether fur marks have a role in social communication is to understand whether such body patches are stable over time (i.e., whether they represent a unique visual signature for every individual). During the period 1999–2021, we recorded yearly pictures of 7 female (mean no. of monitoring years per bear = 13.6, standard deviation [SD] = 4.6; range = 9–22 yr) and 6 male (mean no. of monitoring years per bear = 9.3, SD = 4.3; range = 5–15 yr) brown bears (Ursus arctos) in the Cantabrian Mountains (NW Spain). We show that body mark shapes are stable over time and, because of their uniqueness, might represent a distinctive signature of individuals. Brown bear body marks may act as multicomponent signals, where different features of a given mark may inform about different aspects of the bearer or act as back-ups. For example, a quality-signaling capacity does not preclude the same mark from being used in other functions at the same time, such as individual recognition. Noninvasive techniques helpful for identifying individuals have been developed for estimating population size, reproductive rates, and the survival of several carnivore species. Fur marks that are stable over time can thus be useful in field research (e.g., body marks that are persistent and do not vary over time are an important tool in longitudinal photographic capture–recapture studies).
{"title":"Brown bear body patches are temporally stable and represent a unique individual visual signature","authors":"V. Penteriani, Alfonso Hartasánchez, Juan Díaz García, José Ramón Magadan Ruitiña, María del Mar Delgado","doi":"10.2192/URSUS-D-22-00015","DOIUrl":"https://doi.org/10.2192/URSUS-D-22-00015","url":null,"abstract":"Abstract: Patches of color may be used to communicate to conspecifics, mainly in species showing uniform coloration, and may (a) help individuals maintain visual contact, such as between mothers and their young; (b) function as signals of subordination or to frighten rivals; (c) warn conspecifics of approaching predators; and/or (d) signal reproductive condition, health, or genetic quality to potential mates. Intraspecific communication represents one of the major evolutionary forces responsible for the coloration of body parts, but the meaning of many of these signals is still unclear. One of the first steps to understanding whether fur marks have a role in social communication is to understand whether such body patches are stable over time (i.e., whether they represent a unique visual signature for every individual). During the period 1999–2021, we recorded yearly pictures of 7 female (mean no. of monitoring years per bear = 13.6, standard deviation [SD] = 4.6; range = 9–22 yr) and 6 male (mean no. of monitoring years per bear = 9.3, SD = 4.3; range = 5–15 yr) brown bears (Ursus arctos) in the Cantabrian Mountains (NW Spain). We show that body mark shapes are stable over time and, because of their uniqueness, might represent a distinctive signature of individuals. Brown bear body marks may act as multicomponent signals, where different features of a given mark may inform about different aspects of the bearer or act as back-ups. For example, a quality-signaling capacity does not preclude the same mark from being used in other functions at the same time, such as individual recognition. Noninvasive techniques helpful for identifying individuals have been developed for estimating population size, reproductive rates, and the survival of several carnivore species. Fur marks that are stable over time can thus be useful in field research (e.g., body marks that are persistent and do not vary over time are an important tool in longitudinal photographic capture–recapture studies).","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"61 1","pages":"1 - 6"},"PeriodicalIF":1.3,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84040392","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}
Pub Date : 2023-01-11DOI: 10.2192/URSUS-D-22-00002.2
Frank T. van Manen, M. Ebinger, C. M. Costello, Daniel D. Bjornlie, Justin G. Clapp, Daniel J. Thompson, M. Haroldson, K. Frey, C. Hendricks, Jeremy M. Nicholson, K. Gunther, Katharine R. Wilmot, H. Cooley, Jennifer K. Fortin-Noreus, P. Hnilicka, D. Tyers
Abstract: In the Greater Yellowstone Ecosystem, counts of female grizzly bears (Ursus arctos) with cubs-of-the-year (females with cubs) from systematic aerial surveys and opportunistic ground sightings are combined with demographic data to derive annual population estimates. We addressed 2 limitations to the monitoring approach. As part of a rule set, a conservative distance of >30 km currently is used as a threshold to assign sightings to unique females with cubs, resulting in underestimation bias. Using telemetry locations of females with cubs collected during 1997–2019, we created 1,000 data sets for each of 5 levels of simulated number of females with cubs, simulated sightings by selecting among these locations, and evaluated the classification performance of alternative distance criteria (12–30 km). Under all scenarios, 12–16-km criteria maximized classification performance and minimized estimation bias; the 16-km criterion was optimal for current conditions and sampling efforts. Our second objective was to test generalized additive models (GAMs) as a flexible trend analysis technique. We simulated 1,000 time series for each of 10 scenarios (10, 15, and 20% decline over periods of 5, 10, and 15 yrs, plus stability), applied GAMs, and assessed metrics associated with the posterior distribution of the instantaneous rate of change. We detected declines among >99.6% of replicates under the 15 and 20% decline scenarios and in 84.7–94.7% of replicates under the 10% decline scenario. From decline onset to first detection, periods ranged from 3.7 (20% decline over 5 yrs) to 11.1 (10% decline over 15 yrs), with 3.9–8.8 years mean duration of detection events. The GAM approach allows detection of directional changes in population trend, including early warning metrics, and stabilization after such changes. Retrospective application of the 16-km distance criterion and GAMs resulted in higher population estimates and growth rates than are reported using current methods.
{"title":"Enhancements to population monitoring of Yellowstone grizzly bears","authors":"Frank T. van Manen, M. Ebinger, C. M. Costello, Daniel D. Bjornlie, Justin G. Clapp, Daniel J. Thompson, M. Haroldson, K. Frey, C. Hendricks, Jeremy M. Nicholson, K. Gunther, Katharine R. Wilmot, H. Cooley, Jennifer K. Fortin-Noreus, P. Hnilicka, D. Tyers","doi":"10.2192/URSUS-D-22-00002.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-22-00002.2","url":null,"abstract":"Abstract: In the Greater Yellowstone Ecosystem, counts of female grizzly bears (Ursus arctos) with cubs-of-the-year (females with cubs) from systematic aerial surveys and opportunistic ground sightings are combined with demographic data to derive annual population estimates. We addressed 2 limitations to the monitoring approach. As part of a rule set, a conservative distance of >30 km currently is used as a threshold to assign sightings to unique females with cubs, resulting in underestimation bias. Using telemetry locations of females with cubs collected during 1997–2019, we created 1,000 data sets for each of 5 levels of simulated number of females with cubs, simulated sightings by selecting among these locations, and evaluated the classification performance of alternative distance criteria (12–30 km). Under all scenarios, 12–16-km criteria maximized classification performance and minimized estimation bias; the 16-km criterion was optimal for current conditions and sampling efforts. Our second objective was to test generalized additive models (GAMs) as a flexible trend analysis technique. We simulated 1,000 time series for each of 10 scenarios (10, 15, and 20% decline over periods of 5, 10, and 15 yrs, plus stability), applied GAMs, and assessed metrics associated with the posterior distribution of the instantaneous rate of change. We detected declines among >99.6% of replicates under the 15 and 20% decline scenarios and in 84.7–94.7% of replicates under the 10% decline scenario. From decline onset to first detection, periods ranged from 3.7 (20% decline over 5 yrs) to 11.1 (10% decline over 15 yrs), with 3.9–8.8 years mean duration of detection events. The GAM approach allows detection of directional changes in population trend, including early warning metrics, and stabilization after such changes. Retrospective application of the 16-km distance criterion and GAMs resulted in higher population estimates and growth rates than are reported using current methods.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"247 1","pages":"1 - 19"},"PeriodicalIF":1.3,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76983255","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}
Pub Date : 2022-12-21DOI: 10.2192/URSUS-D-21-00022.1
Gregory McCann, Keith Pawlowski, Pablo Sinovas, S. Thon
Abstract: A wildlife camera-trapping survey spanning 5 years, from January 2014 to 2021 in Virachey National Park in Northeast Cambodia, turned up notable records of Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus). Both species are in decline throughout Indochina (Vietnam, Laos, and Cambodia) as a result of illegal logging, agricultural and infrastructure development that encroaches on forest habitat, and a widespread snaring crisis that supplies the illegal wildlife trade. We deployed 44 camera traps in 3 separate survey areas, resulting in 133 independent encounters of sun bears, 44 of black bears, and 2 Ursidae, where the species could not be determined. Despite the threats facing both species, our records show that the Park is an important refuge and further, more widespread and structured surveys are warranted to help identify priority areas for bear conservation.
{"title":"Asiatic black bears and sun bears in Virachey National Park, Northeast Cambodia","authors":"Gregory McCann, Keith Pawlowski, Pablo Sinovas, S. Thon","doi":"10.2192/URSUS-D-21-00022.1","DOIUrl":"https://doi.org/10.2192/URSUS-D-21-00022.1","url":null,"abstract":"Abstract: A wildlife camera-trapping survey spanning 5 years, from January 2014 to 2021 in Virachey National Park in Northeast Cambodia, turned up notable records of Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus). Both species are in decline throughout Indochina (Vietnam, Laos, and Cambodia) as a result of illegal logging, agricultural and infrastructure development that encroaches on forest habitat, and a widespread snaring crisis that supplies the illegal wildlife trade. We deployed 44 camera traps in 3 separate survey areas, resulting in 133 independent encounters of sun bears, 44 of black bears, and 2 Ursidae, where the species could not be determined. Despite the threats facing both species, our records show that the Park is an important refuge and further, more widespread and structured surveys are warranted to help identify priority areas for bear conservation.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"29 1","pages":"1 - 9"},"PeriodicalIF":1.3,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82830516","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}
Pub Date : 2022-12-21DOI: 10.2192/URSUS-D-21-00011.1
Chen Hsiao, Y. Ju, Chun-Hao Chang, Sheng-Wei Chen, Hui-Wen Tsai, Ling Wang, Wai-tung. Lin, M. Hwang
Abstract: The Formosan black bear (Ursus thibetanus formosanus, FBB) is an endangered subspecies of Asiatic black bear, geographically isolated in Taiwan from 6 other subspecies on the Asian continent and in Japan. Data on the genetic diversity and structure of wild FBB are lacking, though 2 potential hotspots for FBB occurrence have been identified; Yushan National Park (YNP) and Dasyueshan National Forest Recreation Area (DSY). Elucidating species' genetic structure can help assess the potential risks of population fragmentation and isolation that threaten FBB. Here, we employed 8 FBB-derived microsatellite loci to genotype 139 individuals from fecal samples collected in YNP, 20 captured individuals from both study areas, and 1 fecal sample from DSY, during 2009–2019. The marker set featured high polymorphic information content (mean > 0.699) and appropriate probability of identity (combined P(ID) < 0.0001) for individual identification. We detected high heterozygosity and no evidence of inbreeding in YNP, but the 2 subpopulations presented significant genetic differentiation. All DSY samples were assigned to one genetic cluster or phylogenetic clade, indicating that the DSY subpopulation is monophyletic. However, members of the YNP subpopulation were allocated to diverse lineages, and some YNP samples were partly assigned to the same cluster or clade as DSY individuals. We discuss potential evolutionary scenarios in which the observed population genetic structuring may have evolved. Based on our genetic results, the DSY and YNP subpopulations should be considered 2 separate management units and gene flow between both parts should be promoted.
{"title":"Genetic status and conservation implications of endangered Formosan black bears","authors":"Chen Hsiao, Y. Ju, Chun-Hao Chang, Sheng-Wei Chen, Hui-Wen Tsai, Ling Wang, Wai-tung. Lin, M. Hwang","doi":"10.2192/URSUS-D-21-00011.1","DOIUrl":"https://doi.org/10.2192/URSUS-D-21-00011.1","url":null,"abstract":"Abstract: The Formosan black bear (Ursus thibetanus formosanus, FBB) is an endangered subspecies of Asiatic black bear, geographically isolated in Taiwan from 6 other subspecies on the Asian continent and in Japan. Data on the genetic diversity and structure of wild FBB are lacking, though 2 potential hotspots for FBB occurrence have been identified; Yushan National Park (YNP) and Dasyueshan National Forest Recreation Area (DSY). Elucidating species' genetic structure can help assess the potential risks of population fragmentation and isolation that threaten FBB. Here, we employed 8 FBB-derived microsatellite loci to genotype 139 individuals from fecal samples collected in YNP, 20 captured individuals from both study areas, and 1 fecal sample from DSY, during 2009–2019. The marker set featured high polymorphic information content (mean > 0.699) and appropriate probability of identity (combined P(ID) < 0.0001) for individual identification. We detected high heterozygosity and no evidence of inbreeding in YNP, but the 2 subpopulations presented significant genetic differentiation. All DSY samples were assigned to one genetic cluster or phylogenetic clade, indicating that the DSY subpopulation is monophyletic. However, members of the YNP subpopulation were allocated to diverse lineages, and some YNP samples were partly assigned to the same cluster or clade as DSY individuals. We discuss potential evolutionary scenarios in which the observed population genetic structuring may have evolved. Based on our genetic results, the DSY and YNP subpopulations should be considered 2 separate management units and gene flow between both parts should be promoted.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"46 1","pages":"1 - 13"},"PeriodicalIF":1.3,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73515081","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}
Pub Date : 2022-12-19DOI: 10.2192/URSUS-D-21-00021.2
Satem Longchar, M. Hayward
Abstract: This study presents photographic evidence of 2 species of bears—Asiatic black bear (Ursus thibetanus) and sun bear (Helartos malayanus) from a camera-trap study conducted from January 2020 to June 2021 in Intangki National Park, Nagaland, India, where they were assumed to be extirpated. The presence of bears in Intangki shows the potential for effective species conservation in Nagaland through collaboration with local communities and government management. This finding highlights the need to draw attention to the conservation issues pertaining to large-bodied mammals, such as bears, in poorly monitored areas of the world.
{"title":"First photographic records and conservation status of Asiatic black and sun bears in Nagaland, India","authors":"Satem Longchar, M. Hayward","doi":"10.2192/URSUS-D-21-00021.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-21-00021.2","url":null,"abstract":"Abstract: This study presents photographic evidence of 2 species of bears—Asiatic black bear (Ursus thibetanus) and sun bear (Helartos malayanus) from a camera-trap study conducted from January 2020 to June 2021 in Intangki National Park, Nagaland, India, where they were assumed to be extirpated. The presence of bears in Intangki shows the potential for effective species conservation in Nagaland through collaboration with local communities and government management. This finding highlights the need to draw attention to the conservation issues pertaining to large-bodied mammals, such as bears, in poorly monitored areas of the world.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"18 1","pages":"1 - 7"},"PeriodicalIF":1.3,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74450642","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}
Pub Date : 2022-12-14DOI: 10.2192/URSUS-D-22-00006.1
Taiki Ito, Hinako Katsushima, K. Tomita, Tomoka Matsumoto
Abstract: Cannibalism in brown bears (Ursus arctos) is infrequently reported worldwide. This study reports evidence of brown bear cannibalism in northern Hokkaido, Japan. In April 2017, we found a bear scat containing the body parts of a bear cub. We also found a series of tracks (width of the front track: 16 cm) of an adult male bear near the scat, which were likely associated with the excrement. The scat was found at the end of a long hibernation season and the beginning of mating season of brown bears in Hokkaido. The timing suggests that the cannibalism event was a consequence of infanticide by a male bear as part of mating strategy, namely, sexually selected infanticide.
{"title":"Infanticide or predation? Cannibalism by a brown bear in Hokkaido, Japan","authors":"Taiki Ito, Hinako Katsushima, K. Tomita, Tomoka Matsumoto","doi":"10.2192/URSUS-D-22-00006.1","DOIUrl":"https://doi.org/10.2192/URSUS-D-22-00006.1","url":null,"abstract":"Abstract: Cannibalism in brown bears (Ursus arctos) is infrequently reported worldwide. This study reports evidence of brown bear cannibalism in northern Hokkaido, Japan. In April 2017, we found a bear scat containing the body parts of a bear cub. We also found a series of tracks (width of the front track: 16 cm) of an adult male bear near the scat, which were likely associated with the excrement. The scat was found at the end of a long hibernation season and the beginning of mating season of brown bears in Hokkaido. The timing suggests that the cannibalism event was a consequence of infanticide by a male bear as part of mating strategy, namely, sexually selected infanticide.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"36 1","pages":"1 - 5"},"PeriodicalIF":1.3,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88367606","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}
Pub Date : 2022-07-27DOI: 10.2192/URSUS-D-21-00008.R
J. White, William H. Stiver, M. Steinberg, J. Cissell
Abstract: In Great Smoky Mountains National Park (GRSM or Park), American black bears (Ursus americanus) sometimes exhibit conflict behavior that requires resource managers to act. Management options for conflict bears are limited, and it is necessary to evaluate their effectiveness. We analyzed 26 years (1990–2015) of bear capture data and calculated and compared the success rates of the 2 main techniques used to manage bears exhibiting conflict behavior in GRSM: capture and relocation, and capture and on-site release. Overall success rates, defined as a captured bear that was not recaptured for later conflict behavior, for all conflict bears captured was 74%. Bears that were relocated after their first capture were more successful (87%) than those that were released on-site following their first capture (61%), and median time before recapture was greater for relocated bears (293 days) than those released on-site (65 days).
摘要:在美国大烟山国家公园(Great Smoky Mountains National Park)，美国黑熊(Ursus americanus)有时会表现出冲突行为，需要资源管理者采取行动。冲突熊的管理选择是有限的，有必要评估其有效性。我们分析了26年(1990-2015)的熊捕获数据，并计算和比较了GRSM中出现冲突行为的熊的两种主要管理方法的成功率:捕获和重新安置，捕获和现场释放。总体成功率，定义为捕获的熊没有因为后来的冲突行为而被重新捕获，所有捕获的冲突熊的成功率为74%。第一次捕获后重新安置的熊(87%)比第一次捕获后放归的熊(61%)更成功，重新安置的熊(293天)比放归的熊(65天)更长。
{"title":"Comparing management techniques used on conflict American black bears in Great Smoky Mountains National Park","authors":"J. White, William H. Stiver, M. Steinberg, J. Cissell","doi":"10.2192/URSUS-D-21-00008.R","DOIUrl":"https://doi.org/10.2192/URSUS-D-21-00008.R","url":null,"abstract":"Abstract: In Great Smoky Mountains National Park (GRSM or Park), American black bears (Ursus americanus) sometimes exhibit conflict behavior that requires resource managers to act. Management options for conflict bears are limited, and it is necessary to evaluate their effectiveness. We analyzed 26 years (1990–2015) of bear capture data and calculated and compared the success rates of the 2 main techniques used to manage bears exhibiting conflict behavior in GRSM: capture and relocation, and capture and on-site release. Overall success rates, defined as a captured bear that was not recaptured for later conflict behavior, for all conflict bears captured was 74%. Bears that were relocated after their first capture were more successful (87%) than those that were released on-site following their first capture (61%), and median time before recapture was greater for relocated bears (293 days) than those released on-site (65 days).","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"73 1","pages":"1 - 7"},"PeriodicalIF":1.3,"publicationDate":"2022-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86406916","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}
Pub Date : 2022-07-18DOI: 10.2192/URSUS-D-21-00015.2
K. Joly, Matthew D. Cameron, M. Sorum, D. Gustine, William W. Deacy, G. Hilderbrand
Abstract: Home range size is a basic ecological index related to individual's realized niche. Its size can be influenced by body size, sex, maternal status, population density, habitat productivity, spatiotemporal variation of resources, climate, predation risk, and disturbance. Home range estimation can also be greatly affected by methodology and sampling regime. We used Global Positioning System collar data to assess what factors influenced the size of annual home ranges (space use during a single active season) of 28 female and 8 male brown bears (Ursus arctos) that denned in the Brooks Range of northcentral Alaska, USA, from 2014 to 2017. We used 2 methods to estimate annual home ranges, the Kernel Density Estimate (KDE) and the dynamic Brownian Bridge Movement Model (dBBMM). Contrary to expectations, we did not find that larger bodied bears of the same sex had larger annual home ranges. Annual home ranges of male bears (mean [standard deviation]; 504 [312] km2 and 3,886 [4,279] km2, using dBBMM and KDE, respectively) were 3.7–9.4 times larger than that of females (135 [86] km2 and 411 [738] km2, respectively). We found that greater chum salmon (Oncorhynchus keta) consumption was associated with larger annual home ranges for both sexes. In contrast, coastal brown bear populations that consume high levels of salmon often have small annual home ranges. We suggest that the relatively long distance (up to 100 km) between salmon streams and another key resource, denning habitat, is a reason for the positive association between salmon consumption and annual home range size. Although age was not in our top model for annual home range size, younger bears tended to have larger annual home ranges. We documented the fact that individuals of both sexes had the largest annual home ranges of any we could find for brown bears worldwide, using a traditional measure of space use (KDE). However, very large annual home ranges were associated with nonlocalized movements and the alternative method (dBBMM) to delineate these ranges provided more realistic range estimates. We discuss options and limitations of estimating space use and recommend caution when comparing space use between studies. With large-scale industrial infrastructure approved for development in this previously undeveloped region, the size and drivers of bear annual home ranges have numerous management implications. Brown bears with large annual home ranges in northcentral Alaska, where primary productivity is relatively low and denning habitat often far from salmon-bearing streams, are likely to move outside conservation units and encounter more risks as they interact with human infrastructure.
{"title":"Factors influencing Arctic brown bear annual home range sizes and limitations of home range analyses","authors":"K. Joly, Matthew D. Cameron, M. Sorum, D. Gustine, William W. Deacy, G. Hilderbrand","doi":"10.2192/URSUS-D-21-00015.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-21-00015.2","url":null,"abstract":"Abstract: Home range size is a basic ecological index related to individual's realized niche. Its size can be influenced by body size, sex, maternal status, population density, habitat productivity, spatiotemporal variation of resources, climate, predation risk, and disturbance. Home range estimation can also be greatly affected by methodology and sampling regime. We used Global Positioning System collar data to assess what factors influenced the size of annual home ranges (space use during a single active season) of 28 female and 8 male brown bears (Ursus arctos) that denned in the Brooks Range of northcentral Alaska, USA, from 2014 to 2017. We used 2 methods to estimate annual home ranges, the Kernel Density Estimate (KDE) and the dynamic Brownian Bridge Movement Model (dBBMM). Contrary to expectations, we did not find that larger bodied bears of the same sex had larger annual home ranges. Annual home ranges of male bears (mean [standard deviation]; 504 [312] km2 and 3,886 [4,279] km2, using dBBMM and KDE, respectively) were 3.7–9.4 times larger than that of females (135 [86] km2 and 411 [738] km2, respectively). We found that greater chum salmon (Oncorhynchus keta) consumption was associated with larger annual home ranges for both sexes. In contrast, coastal brown bear populations that consume high levels of salmon often have small annual home ranges. We suggest that the relatively long distance (up to 100 km) between salmon streams and another key resource, denning habitat, is a reason for the positive association between salmon consumption and annual home range size. Although age was not in our top model for annual home range size, younger bears tended to have larger annual home ranges. We documented the fact that individuals of both sexes had the largest annual home ranges of any we could find for brown bears worldwide, using a traditional measure of space use (KDE). However, very large annual home ranges were associated with nonlocalized movements and the alternative method (dBBMM) to delineate these ranges provided more realistic range estimates. We discuss options and limitations of estimating space use and recommend caution when comparing space use between studies. With large-scale industrial infrastructure approved for development in this previously undeveloped region, the size and drivers of bear annual home ranges have numerous management implications. Brown bears with large annual home ranges in northcentral Alaska, where primary productivity is relatively low and denning habitat often far from salmon-bearing streams, are likely to move outside conservation units and encounter more risks as they interact with human infrastructure.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"107 1","pages":"1 - 12"},"PeriodicalIF":1.3,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80707862","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}
Pub Date : 2022-07-12DOI: 10.2192/URSUS-D-20-00031.2
M. L. Allen, M. Krofel, K. Yamazaki, Emmarie P. Alexander, S. Koike
Abstract: Bears are the largest terrestrial carnivores, and most bear species can be characterized as opportunistic omnivores. An infrequent foraging tactic for bears is cannibalism, where a bear consumes a conspecific individual, either through scavenging or following intraspecific predation. Although several reports of cannibalism events are known, no attempt has been made so far to gather the available information to analyze for general patterns. We therefore performed a systematic literature review to understand patterns of cannibalism in bears. We documented 39 studies detailing 198 cannibalism events. We only found evidence of cannibalism in 4 of the 8 bear species, with more events reported for polar bears (Ursus maritimus; n = 107, 54.0%) than for all other species combined. Cannibalism was most frequently associated with infanticide (n = 66, 33.3%) and conspecific strife (n = 30, 15.2%), both of which were more frequent among males than females. The most common apparent reason for cannibalism among predators is to increase fitness (i.e., eating a conspecific increases nutrition, whereas killing reduces competition for resources), but is also often linked to sexually selected infanticide in bears. Cannibalism most often appears to be an opportunistic consumption of an available carcass and not directly connected with the primary cause of death. As such, cannibalism in bears may be more casual and opportunistic than a behavior that evolved as a life history strategy.
{"title":"Cannibalism in bears","authors":"M. L. Allen, M. Krofel, K. Yamazaki, Emmarie P. Alexander, S. Koike","doi":"10.2192/URSUS-D-20-00031.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-20-00031.2","url":null,"abstract":"Abstract: Bears are the largest terrestrial carnivores, and most bear species can be characterized as opportunistic omnivores. An infrequent foraging tactic for bears is cannibalism, where a bear consumes a conspecific individual, either through scavenging or following intraspecific predation. Although several reports of cannibalism events are known, no attempt has been made so far to gather the available information to analyze for general patterns. We therefore performed a systematic literature review to understand patterns of cannibalism in bears. We documented 39 studies detailing 198 cannibalism events. We only found evidence of cannibalism in 4 of the 8 bear species, with more events reported for polar bears (Ursus maritimus; n = 107, 54.0%) than for all other species combined. Cannibalism was most frequently associated with infanticide (n = 66, 33.3%) and conspecific strife (n = 30, 15.2%), both of which were more frequent among males than females. The most common apparent reason for cannibalism among predators is to increase fitness (i.e., eating a conspecific increases nutrition, whereas killing reduces competition for resources), but is also often linked to sexually selected infanticide in bears. Cannibalism most often appears to be an opportunistic consumption of an available carcass and not directly connected with the primary cause of death. As such, cannibalism in bears may be more casual and opportunistic than a behavior that evolved as a life history strategy.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"75 1","pages":"1 - 9"},"PeriodicalIF":1.3,"publicationDate":"2022-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86337008","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}
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