Pub Date : 2018-12-01DOI: 10.2192/URSUS-D-18-00001.1
I. Hatter, G. Mowat, B. Mclellan
Abstract Grizzly bear (Ursus arctos) populations are costly to monitor by traditional survey methods. In British Columbia, Canada, hunter kill data are available and provide relatively inexpensive information that possibly can be used to estimate trends in hunted populations. We applied statistical population reconstruction (SPR) using Program PopRecon 2.0 to evaluate trends in abundance of ≥3-year-old male grizzly bears for 3 large areas in British Columbia. Model inputs included annual estimates of age-at-kill and hunter effort, combined with auxiliary information on population abundance in 2012, and a non-hunting survival rate. Modeled abundance in all 3 areas was sensitive to the auxiliary abundance estimate but less so for the auxiliary survival estimate or the length of the time series. Relative trends in abundance appeared to be primarily affected by kill and effort data and were less affected by the auxiliary data. The gradual increase in abundance within the Temperate Mountains area from 1985 to 2004 followed by an apparent decline was consistent with other independent studies and supported the premise that grizzly bear numbers were recovering from a population low until between 2000 and 2005. Our results suggest that the grizzly bear population in the Boreal–Sub-boreal area was also recovering during this period. Our analysis demonstrates the potential utility of SPR for monitoring grizzly bear population trends, but results from the Coastal area also highlight the importance of sufficient hunter-kill and -effort data, in addition to quality auxiliary data, to detect population change. Future enhancements in Program PopRecon may help improve the performance and utility of SPR for grizzly bears in British Columbia.
{"title":"Statistical population reconstruction to evaluate grizzly bear trends in British Columbia, Canada","authors":"I. Hatter, G. Mowat, B. Mclellan","doi":"10.2192/URSUS-D-18-00001.1","DOIUrl":"https://doi.org/10.2192/URSUS-D-18-00001.1","url":null,"abstract":"Abstract Grizzly bear (Ursus arctos) populations are costly to monitor by traditional survey methods. In British Columbia, Canada, hunter kill data are available and provide relatively inexpensive information that possibly can be used to estimate trends in hunted populations. We applied statistical population reconstruction (SPR) using Program PopRecon 2.0 to evaluate trends in abundance of ≥3-year-old male grizzly bears for 3 large areas in British Columbia. Model inputs included annual estimates of age-at-kill and hunter effort, combined with auxiliary information on population abundance in 2012, and a non-hunting survival rate. Modeled abundance in all 3 areas was sensitive to the auxiliary abundance estimate but less so for the auxiliary survival estimate or the length of the time series. Relative trends in abundance appeared to be primarily affected by kill and effort data and were less affected by the auxiliary data. The gradual increase in abundance within the Temperate Mountains area from 1985 to 2004 followed by an apparent decline was consistent with other independent studies and supported the premise that grizzly bear numbers were recovering from a population low until between 2000 and 2005. Our results suggest that the grizzly bear population in the Boreal–Sub-boreal area was also recovering during this period. Our analysis demonstrates the potential utility of SPR for monitoring grizzly bear population trends, but results from the Coastal area also highlight the importance of sufficient hunter-kill and -effort data, in addition to quality auxiliary data, to detect population change. Future enhancements in Program PopRecon may help improve the performance and utility of SPR for grizzly bears in British Columbia.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"12 1","pages":"1 - 12"},"PeriodicalIF":1.3,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72802043","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 : 2018-12-01DOI: 10.2192/URSUS-D-17-00020.2
Dario F. Cueva, B. Gutiérrez, Gabriela Bruque, Santiago Molina, M. Torres
Abstract Few studies have analyzed the genetics of Andean bear (Tremarctos ornatus) populations through the use of the hypervariable D-Loop mitochondrial region. This approach can be useful for the assessment of genetic diversity and ancestral lineages. In the present study we evaluate the genetic status of an Andean bear population in northern Ecuador using D-loop mtDNA sequence polymorphisms. For this purpose, DNA from individuals sampled in the Metropolitan District of Quito was used to amplify and sequence a fragment of the hypervariable D-loop region. Our results show remarkably low levels of genetic diversity, based on haplotype (H) and nucleotide (π) diversity indices, and low pairwise genetic distances between haplotypes. Phylogenetic analyses suggest that these haplotypes are clustered into a single monophyletic group. These diversity indices are among the lowest reported for any bear population, suggesting a need to establish or revise the current conservation strategies in the region.
{"title":"Mitochondrial DNA reveals low genetic diversity in Ecuadorian Andean bears","authors":"Dario F. Cueva, B. Gutiérrez, Gabriela Bruque, Santiago Molina, M. Torres","doi":"10.2192/URSUS-D-17-00020.2","DOIUrl":"https://doi.org/10.2192/URSUS-D-17-00020.2","url":null,"abstract":"Abstract Few studies have analyzed the genetics of Andean bear (Tremarctos ornatus) populations through the use of the hypervariable D-Loop mitochondrial region. This approach can be useful for the assessment of genetic diversity and ancestral lineages. In the present study we evaluate the genetic status of an Andean bear population in northern Ecuador using D-loop mtDNA sequence polymorphisms. For this purpose, DNA from individuals sampled in the Metropolitan District of Quito was used to amplify and sequence a fragment of the hypervariable D-loop region. Our results show remarkably low levels of genetic diversity, based on haplotype (H) and nucleotide (π) diversity indices, and low pairwise genetic distances between haplotypes. Phylogenetic analyses suggest that these haplotypes are clustered into a single monophyletic group. These diversity indices are among the lowest reported for any bear population, suggesting a need to establish or revise the current conservation strategies in the region.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"12 1","pages":"43 - 50"},"PeriodicalIF":1.3,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91109272","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 : 2017-12-18DOI: 10.2192/URSU-D-17-00010.1
J. B. Mesa-Cruz, K. Lahmers, S. Clark-Deener, N. Pavlisko, M. Kelly
Abstract: Herniation of viscera induced by medical intervention has been described in carnivores, yet occurrence of hernias causing wild carnivore mortality, including in bears, remains unknown. We describe an inguinal hernia, intestinal entrapment and rupture, and peritonitis causing mortality in a male American black bear (Ursus americanus). In the autumn of 2014, a free-ranging, adult bear was housed at Virginia Tech's Black Bear Research Center. After 13 days in captivity, the bear showed signs of lethargy and intermittent inappetence consistent with the onset of hibernating behaviors. However, the bear suddenly displayed rapid deterioration and died before medical assistance could be provided. During necropsy examination, a devitalized portion of small intestine was found entrapped in the left inguinal ring. An intestinal perforation was evident near the entrapment area, which caused a subsequent peritonitis. To our knowledge this is the first report of bear mortality due to inguinal herniation with subsequent perforation and peritonitis.
{"title":"Inguinal hernia causes mortality in an adult American black bear","authors":"J. B. Mesa-Cruz, K. Lahmers, S. Clark-Deener, N. Pavlisko, M. Kelly","doi":"10.2192/URSU-D-17-00010.1","DOIUrl":"https://doi.org/10.2192/URSU-D-17-00010.1","url":null,"abstract":"Abstract: Herniation of viscera induced by medical intervention has been described in carnivores, yet occurrence of hernias causing wild carnivore mortality, including in bears, remains unknown. We describe an inguinal hernia, intestinal entrapment and rupture, and peritonitis causing mortality in a male American black bear (Ursus americanus). In the autumn of 2014, a free-ranging, adult bear was housed at Virginia Tech's Black Bear Research Center. After 13 days in captivity, the bear showed signs of lethargy and intermittent inappetence consistent with the onset of hibernating behaviors. However, the bear suddenly displayed rapid deterioration and died before medical assistance could be provided. During necropsy examination, a devitalized portion of small intestine was found entrapped in the left inguinal ring. An intestinal perforation was evident near the entrapment area, which caused a subsequent peritonitis. To our knowledge this is the first report of bear mortality due to inguinal herniation with subsequent perforation and peritonitis.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"65 1","pages":"131 - 134"},"PeriodicalIF":1.3,"publicationDate":"2017-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73965827","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 : 2017-11-01DOI: 10.2192/URSU-D-16-00033.1
Andrew N. Tri, J. Edwards, C. W. Ryan, Colin P. Carpenter, Patrick C. Carr, Mark A. Ternent, M. Strager, J. Petty
Abstract: There is a salient belief that bears (Ursidae) using the wildland–urban interface (WUI) are not vulnerable to harvest, and therefore, hunting is an ineffective management tool for bears in the WUI of the eastern United States; however, this question remains untested. We fit and monitored 116 American black bears (Ursus americanus; hereafter, black bear) with Global Positioning System–Global System for Mobile Communications collars in 9 municipalities in New Jersey, Pennsylvania, and West Virginia, USA, during 2010–2013 to determine (1) whether bears in the WUI were vulnerable to harvest; (2) if so, at what rates are they harvested; and (3) what are other cause-specific mortalities in the WUI. Harvest mortality did occur on the monitored bears in the WUI during our study. Harvest mortality rates were lower than statewide tag-return harvest rates from New Jersey and higher 3 of 4 years in Pennsylvania. The proportion of bears that was harvested was similar for juvenile males (30%), adult males (36%), and adult females (29%). Annual survival was variable (range = 40–92%), but was similar among adult males and females. Euthanasia accounted for 8–19% of the total mortality in New Jersey and West Virginia but only 3% in Pennsylvania. Black bears in the WUI were vulnerable to harvest; therefore, we consider regulated harvest to be a viable management tool. Agencies may prefer that hunters act as a compensatory mortality mechanism by harvesting problem bears that would otherwise be euthanized or killed in bear–vehicle collisions.
{"title":"Harvest rates and cause-specific mortality of American black bears in the wildland–urban interface of the Mid-Atlantic region, USA","authors":"Andrew N. Tri, J. Edwards, C. W. Ryan, Colin P. Carpenter, Patrick C. Carr, Mark A. Ternent, M. Strager, J. Petty","doi":"10.2192/URSU-D-16-00033.1","DOIUrl":"https://doi.org/10.2192/URSU-D-16-00033.1","url":null,"abstract":"Abstract: There is a salient belief that bears (Ursidae) using the wildland–urban interface (WUI) are not vulnerable to harvest, and therefore, hunting is an ineffective management tool for bears in the WUI of the eastern United States; however, this question remains untested. We fit and monitored 116 American black bears (Ursus americanus; hereafter, black bear) with Global Positioning System–Global System for Mobile Communications collars in 9 municipalities in New Jersey, Pennsylvania, and West Virginia, USA, during 2010–2013 to determine (1) whether bears in the WUI were vulnerable to harvest; (2) if so, at what rates are they harvested; and (3) what are other cause-specific mortalities in the WUI. Harvest mortality did occur on the monitored bears in the WUI during our study. Harvest mortality rates were lower than statewide tag-return harvest rates from New Jersey and higher 3 of 4 years in Pennsylvania. The proportion of bears that was harvested was similar for juvenile males (30%), adult males (36%), and adult females (29%). Annual survival was variable (range = 40–92%), but was similar among adult males and females. Euthanasia accounted for 8–19% of the total mortality in New Jersey and West Virginia but only 3% in Pennsylvania. Black bears in the WUI were vulnerable to harvest; therefore, we consider regulated harvest to be a viable management tool. Agencies may prefer that hunters act as a compensatory mortality mechanism by harvesting problem bears that would otherwise be euthanized or killed in bear–vehicle collisions.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"28 1","pages":"195 - 207"},"PeriodicalIF":1.3,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84636086","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 : 2017-11-01DOI: 10.2192/URSU-D-16-00012.1
V. Penteriani, María del Mar Delgado, J. López‐Bao, Pablo Vázquez García, J. S. Monrós, Efrén Vigón Álvarez, Teresa Sánchez Corominas, V. M. Vázquez
Abstract: Between 2008 and 2013, 3 female brown bears (Ursus arctos; 2 cubs-of-the-year and 1 2-yr-old) were rescued, rehabilitated in captivity, radiotagged, and released back to the Cantabrian Mountains, northwestern Spain. We characterized their daily and seasonal movements post-release to gain insights into their movement strategies and the viability of bears released in human-dominated environments. The bears exhibited marked diurnal activity and were active throughout winter. Two bears demonstrated behaviors similar to those reported for wild bears, whereas one cub-of-the-year was recaptured after 21 days because she developed signs of habituation to humans.
{"title":"Patterns of movement of released female brown bears in the Cantabrian Mountains, northwestern Spain","authors":"V. Penteriani, María del Mar Delgado, J. López‐Bao, Pablo Vázquez García, J. S. Monrós, Efrén Vigón Álvarez, Teresa Sánchez Corominas, V. M. Vázquez","doi":"10.2192/URSU-D-16-00012.1","DOIUrl":"https://doi.org/10.2192/URSU-D-16-00012.1","url":null,"abstract":"Abstract: Between 2008 and 2013, 3 female brown bears (Ursus arctos; 2 cubs-of-the-year and 1 2-yr-old) were rescued, rehabilitated in captivity, radiotagged, and released back to the Cantabrian Mountains, northwestern Spain. We characterized their daily and seasonal movements post-release to gain insights into their movement strategies and the viability of bears released in human-dominated environments. The bears exhibited marked diurnal activity and were active throughout winter. Two bears demonstrated behaviors similar to those reported for wild bears, whereas one cub-of-the-year was recaptured after 21 days because she developed signs of habituation to humans.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"83 1","pages":"165 - 170"},"PeriodicalIF":1.3,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76125948","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 : 2017-11-01DOI: 10.2192/URSU-D-16-00021.1
M. Obbard, E. Newton, D. Potter, A. Orton, B. Patterson, B. Steinberg
Abstract: Protected areas may provide insufficient protection for carnivores such as bears (Ursidae) with large home ranges and extensive seasonal movements. Even in protected areas, harvest can be the main cause of mortality if parks are small or individuals live close to the boundary. At >7,600 km2, Algonquin Provincial Park (APP) is the largest protected area in southern Ontario, Canada, yet wolves (Canis lycaon c.f.) experienced increased mortality when leaving APP to hunt white-tailed deer (Odocoileus virginianus). American black bears (Ursus americanus; hereafter, bears) also undertake seasonal movements, and may incur increased risk of harvest related mortality if they leave the park. We fitted 72 bears with Global Positioning System or Very High Frequency radiocollars during 2006–2014 to determine overall and cause-specific mortality rates, and whether risk of mortality changed when bears left APP or during years of low natural food availability. Further, we compared the abundance of resident bears with harvest rates in Wildlife Management Units (WMUs) surrounding APP to determine whether harvest was higher in areas surrounding the park compared with WMUs farther from the park boundary. Hazard analysis showed annual mortality for radiocollared bears in APP was 15%. Harvest mortality was double that of all other causes combined. Bears were 7 times more likely to die outside the park. Years of lower natural food availability inside the park, or higher red oak (Quercus rubra) availability outside the park did not significantly alter the risk of mortality. Male bears were 6 times more likely to be harvested than females, and 4 times more likely to die from other causes. High harvests of bears in WMUs near APP contrasted with low abundance of resident bears, suggesting that APP acts as a source population for harvest that occurs near park boundaries. Meaningful maintenance of the integrity of bear populations in protected areas should be undertaken at the landscape scale.
{"title":"Big enough for bears? American black bears at heightened risk of mortality during seasonal forays outside Algonquin Provincial Park, Ontario","authors":"M. Obbard, E. Newton, D. Potter, A. Orton, B. Patterson, B. Steinberg","doi":"10.2192/URSU-D-16-00021.1","DOIUrl":"https://doi.org/10.2192/URSU-D-16-00021.1","url":null,"abstract":"Abstract: Protected areas may provide insufficient protection for carnivores such as bears (Ursidae) with large home ranges and extensive seasonal movements. Even in protected areas, harvest can be the main cause of mortality if parks are small or individuals live close to the boundary. At >7,600 km2, Algonquin Provincial Park (APP) is the largest protected area in southern Ontario, Canada, yet wolves (Canis lycaon c.f.) experienced increased mortality when leaving APP to hunt white-tailed deer (Odocoileus virginianus). American black bears (Ursus americanus; hereafter, bears) also undertake seasonal movements, and may incur increased risk of harvest related mortality if they leave the park. We fitted 72 bears with Global Positioning System or Very High Frequency radiocollars during 2006–2014 to determine overall and cause-specific mortality rates, and whether risk of mortality changed when bears left APP or during years of low natural food availability. Further, we compared the abundance of resident bears with harvest rates in Wildlife Management Units (WMUs) surrounding APP to determine whether harvest was higher in areas surrounding the park compared with WMUs farther from the park boundary. Hazard analysis showed annual mortality for radiocollared bears in APP was 15%. Harvest mortality was double that of all other causes combined. Bears were 7 times more likely to die outside the park. Years of lower natural food availability inside the park, or higher red oak (Quercus rubra) availability outside the park did not significantly alter the risk of mortality. Male bears were 6 times more likely to be harvested than females, and 4 times more likely to die from other causes. High harvests of bears in WMUs near APP contrasted with low abundance of resident bears, suggesting that APP acts as a source population for harvest that occurs near park boundaries. Meaningful maintenance of the integrity of bear populations in protected areas should be undertaken at the landscape scale.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"26 1","pages":"182 - 194"},"PeriodicalIF":1.3,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79941753","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 : 2017-11-01DOI: 10.2192/URSU-D-17-00014.1
Diana L. Doan-Crider, Andrew N. Tri, D. Hewitt
Abstract: American black bear (Ursus americanus; hereafter, bear) depredation on cattle is a rare occurrence. Our study population of bears normally coexists with cattle ranching operations in Serranias del Burro, Coahuila, Mexico. However, we observed unusually high incidences of depredation upon cattle during a severe drought in 1999–2000. We documented >60 reports of calf kills among 3 herds; we were able to locate exact kill-site locations for 16 of these cases. Of the 16 kills, 15 were of calves and 1 was of a cow giving birth, which resulted in the death of both cow and calf. We used logistic regression to quantify how landscape features (i.e., grassland vs. woody habitats, distance to screening cover, and distance to water source at 16 kill sites and 26 random sites) influenced probability of cattle kills. Of known kill locations, 88% of kills (n = 14) took place in woody vegetation while 12% (n = 2) took place in grassland. Our analysis indicated that habitat type (woody vs. grassland) and distance to water source were important factors in predicting bear depredation on cattle. Mean probability of depredation was 2–3 times greater in woody vegetation than in open grassland and was highest near water tanks. The probability of encounter between bears and cattle likely increased as they localized movements around watering areas, which happened to coincide with calving areas and season. Bears utilized screening cover to approach and drag off calves while mother cows were foraging. Supervising and keeping cattle in grassland areas until calves are ≥1 month old and providing alternate water sources outside of calving areas may reduce the potential for conflict. Drought may increase the potential for conflict, so cattle management strategies during periods of low rainfall should be altered to minimize losses.
{"title":"Woody cover and proximity to water increase American black bear depredation on cattle in Coahuila, Mexico","authors":"Diana L. Doan-Crider, Andrew N. Tri, D. Hewitt","doi":"10.2192/URSU-D-17-00014.1","DOIUrl":"https://doi.org/10.2192/URSU-D-17-00014.1","url":null,"abstract":"Abstract: American black bear (Ursus americanus; hereafter, bear) depredation on cattle is a rare occurrence. Our study population of bears normally coexists with cattle ranching operations in Serranias del Burro, Coahuila, Mexico. However, we observed unusually high incidences of depredation upon cattle during a severe drought in 1999–2000. We documented >60 reports of calf kills among 3 herds; we were able to locate exact kill-site locations for 16 of these cases. Of the 16 kills, 15 were of calves and 1 was of a cow giving birth, which resulted in the death of both cow and calf. We used logistic regression to quantify how landscape features (i.e., grassland vs. woody habitats, distance to screening cover, and distance to water source at 16 kill sites and 26 random sites) influenced probability of cattle kills. Of known kill locations, 88% of kills (n = 14) took place in woody vegetation while 12% (n = 2) took place in grassland. Our analysis indicated that habitat type (woody vs. grassland) and distance to water source were important factors in predicting bear depredation on cattle. Mean probability of depredation was 2–3 times greater in woody vegetation than in open grassland and was highest near water tanks. The probability of encounter between bears and cattle likely increased as they localized movements around watering areas, which happened to coincide with calving areas and season. Bears utilized screening cover to approach and drag off calves while mother cows were foraging. Supervising and keeping cattle in grassland areas until calves are ≥1 month old and providing alternate water sources outside of calving areas may reduce the potential for conflict. Drought may increase the potential for conflict, so cattle management strategies during periods of low rainfall should be altered to minimize losses.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"9 1","pages":"208 - 217"},"PeriodicalIF":1.3,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91251470","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 : 2017-11-01DOI: 10.2192/URSU-D-16-00028.1
S. Frank, A. Ordiz, Jacinthe Gosselin, A. Hertel, J. Kindberg, Martin Leclerc, F. Pelletier, S. Steyaert, O. Støen, Joanie Van de Walle, A. Zedrosser, J. Swenson
Abstract: Harvest by means of hunting is a commonly used tool in large carnivore management. To evaluate the effects of harvest on populations, managers usually focus on numerical or immediate direct demographic effects of harvest mortality on a population's size and growth. However, we suggest that managers should also give consideration to indirect and potential evolutionary effects of hunting (e.g., the consequences of a change in the age, sex, and social structure), and their effects on population growth rate. We define “indirect effects” as hunting-induced changes in a population, including human-induced selection, that result in an additive change to the population growth rate “lambda” beyond that due to the initial offtake from direct mortality. We considered 4 major sources of possible indirect effects from hunting of bears: (1) changes to a population's age and sex structure, (2) changes to a population's social structure, (3) changes in individual behavior, and (4) human-induced selection. We identified empirically supported, as well as expected, indirect effects of hunting based primarily on >30 years of research on the Scandinavian brown bear (Ursus arctos) population. We stress that some indirect effects have been documented (e.g., habitat use and daily activity patterns of bears change when hunting seasons start, and changes in male social structure induce sexually selected infanticide and reduce population growth). Other effects may be more difficult to document and quantify in wild bear populations (e.g., how a younger age structure in males may lead to decreased offspring survival). We suggest that managers of bear and other large carnivore populations adopt a precautionary approach and assume that indirect effects do exist, have a potential impact on population structure, and, ultimately, may have an effect on population growth that differs from that predicted by harvest models based on direct effects alone.
{"title":"Indirect effects of bear hunting: a review from Scandinavia","authors":"S. Frank, A. Ordiz, Jacinthe Gosselin, A. Hertel, J. Kindberg, Martin Leclerc, F. Pelletier, S. Steyaert, O. Støen, Joanie Van de Walle, A. Zedrosser, J. Swenson","doi":"10.2192/URSU-D-16-00028.1","DOIUrl":"https://doi.org/10.2192/URSU-D-16-00028.1","url":null,"abstract":"Abstract: Harvest by means of hunting is a commonly used tool in large carnivore management. To evaluate the effects of harvest on populations, managers usually focus on numerical or immediate direct demographic effects of harvest mortality on a population's size and growth. However, we suggest that managers should also give consideration to indirect and potential evolutionary effects of hunting (e.g., the consequences of a change in the age, sex, and social structure), and their effects on population growth rate. We define “indirect effects” as hunting-induced changes in a population, including human-induced selection, that result in an additive change to the population growth rate “lambda” beyond that due to the initial offtake from direct mortality. We considered 4 major sources of possible indirect effects from hunting of bears: (1) changes to a population's age and sex structure, (2) changes to a population's social structure, (3) changes in individual behavior, and (4) human-induced selection. We identified empirically supported, as well as expected, indirect effects of hunting based primarily on >30 years of research on the Scandinavian brown bear (Ursus arctos) population. We stress that some indirect effects have been documented (e.g., habitat use and daily activity patterns of bears change when hunting seasons start, and changes in male social structure induce sexually selected infanticide and reduce population growth). Other effects may be more difficult to document and quantify in wild bear populations (e.g., how a younger age structure in males may lead to decreased offspring survival). We suggest that managers of bear and other large carnivore populations adopt a precautionary approach and assume that indirect effects do exist, have a potential impact on population structure, and, ultimately, may have an effect on population growth that differs from that predicted by harvest models based on direct effects alone.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"9 1","pages":"150 - 164"},"PeriodicalIF":1.3,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84301243","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 : 2017-11-01DOI: 10.2192/URSU-D-17-00002.1
Sterling Miller, J. Schoen, C. C. Schwartz
Abstract: For >35 years Alaska, USA, has attempted to reduce brown bear (Ursus arctos) abundance through adoption of progressively more liberal hunting regulations. We document these changes in a portion of Alaska we term the Liberal [brown bear] Hunting Area (LHA) constituting 76% of Alaska's area. In most instances, regulation liberalizations were intended to reduce brown bear abundance in the expectation this would reduce predation by bears on wild ungulates and thereby increase hunter harvests of these ungulates. Miller et al. (2011) described the hunting regulation changes in the LHA and corresponding increases in brown bear harvests through 2010. We update the changes in regulations and harvests through 2017 and report a shift in the kinds of regulations liberalized. We also document the expansion of regulations pertaining to brown bear population reduction to the small and isolated population on Alaska's Kenai Peninsula (outside the LHA) that resulted in a 25-fold harvest increase in the year of regulation liberalization. This increase caused a conflict with federal managers of the Kenai National Wildlife Refuge. The result was congressionally imposed constraints on the ability of managers of Alaskan national wildlife refuges to manage wildlife on refuge lands in ways federal managers deemed to be in the U.S. national interest. Ongoing litigation and policy changes may result in the same outcome for Alaskan national parks, preserves, and monuments. In the LHA during 1995–2017, we tabulated 222 regulatory changes in Game Management Subunits making brown bear hunting regulations more liberal and 4 changes making regulations more conservative. Since 2000, the State of Alaska has reported no research in the LHA that would permit evaluation of the impacts of these regulatory changes and correlated harvest increases on bear abundance or demographics.
摘要:在过去的35年里，美国阿拉斯加州一直试图通过逐步放宽狩猎规定来减少棕熊(Ursus arctos)的数量。我们在阿拉斯加的一部分记录了这些变化，我们称之为自由[棕熊]狩猎区(LHA)，占阿拉斯加面积的76%。在大多数情况下，管制自由化的目的是减少棕熊的数量，期望这将减少熊对野生有蹄类动物的捕食，从而增加这些有蹄类动物的猎人收成。Miller et al.(2011)描述了2010年LHA狩猎规则的变化以及相应的棕熊收获量的增加。我们更新了2017年的法规和收成变化，并报告了放宽法规种类的变化。我们还记录了有关棕熊种群减少的法规扩大到阿拉斯加基奈半岛(LHA之外)的小而孤立的种群，导致法规自由化的那一年收获量增加了25倍。这一增长引起了与基奈国家野生动物保护区的联邦管理人员的冲突。其结果是，国会对阿拉斯加国家野生动物保护区管理者以联邦管理者认为符合美国国家利益的方式管理保护区土地上野生动物的能力施加了限制。正在进行的诉讼和政策变化可能会对阿拉斯加国家公园、保护区和纪念碑造成同样的结果。在1995-2017年的LHA中，我们列出了222个游戏管理亚单位的监管变化，这些变化使棕熊狩猎法规更加自由，而4个变化使法规更加保守。自2000年以来，阿拉斯加州没有报告任何关于LHA的研究，这些研究将允许评估这些监管变化和相关收获增加对熊数量或人口统计的影响。
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Pub Date : 2017-11-01DOI: 10.2192/URSU-D-16-00029.1
A. Pagano, K. Rode, S. Atkinson
Abstract: An animal's body condition provides insight into its health, foraging success, and overall fitness. Measures of body composition including proportional fat content are useful indicators of condition. Isotopic dilution is a reliable non-destructive method for estimating the body composition of live mammals, but can require prolonged handling times. Alternatively, bioelectrical impedance analysis (BIA) has promise as a quick method for estimating the body composition of live mammals, but measurements can potentially be affected by field conditions. Body condition indices (BCI) and energy density models can also be used to assess body condition based on morphological measurements, but may not reliably reflect an animal's energy stores. Here we evaluate BIA, BCI, and an energy density model in measuring the energy stores of female polar bears (Ursus maritimus). We examine the relationship between total body fat (TBF) derived from isotopic dilution to these alternative methods for 9 female polar bears from 14 captures on the sea ice of the southern Beaufort Sea in April 2014–2016. An energy density model, BCI, and BIA-derived measures of TBF were poor predictors of TBF derived from isotopic dilution. We suggest energy density, BCI, and BIA may not be predictive of an animal's body fat at fine scales (e.g., among individuals within the same sex, reproductive status, and season). In particular, BIA should provide similar measures of body composition as isotopic dilution, but it failed to reliably measure TBF of individual bears. These limitations in the precision of body condition measures should be considered when planning future studies.
{"title":"Evaluating methods to assess the body condition of female polar bears","authors":"A. Pagano, K. Rode, S. Atkinson","doi":"10.2192/URSU-D-16-00029.1","DOIUrl":"https://doi.org/10.2192/URSU-D-16-00029.1","url":null,"abstract":"Abstract: An animal's body condition provides insight into its health, foraging success, and overall fitness. Measures of body composition including proportional fat content are useful indicators of condition. Isotopic dilution is a reliable non-destructive method for estimating the body composition of live mammals, but can require prolonged handling times. Alternatively, bioelectrical impedance analysis (BIA) has promise as a quick method for estimating the body composition of live mammals, but measurements can potentially be affected by field conditions. Body condition indices (BCI) and energy density models can also be used to assess body condition based on morphological measurements, but may not reliably reflect an animal's energy stores. Here we evaluate BIA, BCI, and an energy density model in measuring the energy stores of female polar bears (Ursus maritimus). We examine the relationship between total body fat (TBF) derived from isotopic dilution to these alternative methods for 9 female polar bears from 14 captures on the sea ice of the southern Beaufort Sea in April 2014–2016. An energy density model, BCI, and BIA-derived measures of TBF were poor predictors of TBF derived from isotopic dilution. We suggest energy density, BCI, and BIA may not be predictive of an animal's body fat at fine scales (e.g., among individuals within the same sex, reproductive status, and season). In particular, BIA should provide similar measures of body composition as isotopic dilution, but it failed to reliably measure TBF of individual bears. These limitations in the precision of body condition measures should be considered when planning future studies.","PeriodicalId":49393,"journal":{"name":"Ursus","volume":"57 1","pages":"171 - 181"},"PeriodicalIF":1.3,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82278690","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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