Knowledge of large carnivore population abundance is essential for wildlife management and conservation,but these data are often difficult to obtain in inherently low-density species.In particular,the snow leopard,Pan...Knowledge of large carnivore population abundance is essential for wildlife management and conservation,but these data are often difficult to obtain in inherently low-density species.In particular,the snow leopard,Panthera uncia,an enigmatic cat occupying remote mountains in Central Asia,has received insufficient assessments of its population abundance because of logistical and methodological challenges.Here,we aimed to develop a robust density estimation of snow leopards based on 81 days of camera trapping within a contiguous and previously un-surveyed 1950 km^(2)area of habitat on the Tibetan Plateau(Mayue Township,Shenzha County,Xizang Autonomous Region,China).By applying spatially explicit capture-recapture models,we produced an estimate of 1.40(95%CI:1.06-1.84)individuals per 100 km^(2).Results also suggested sex-specific variation in the range of movement around activity centers,with male(N=10,σ=4.02)movement considerably greater than female(N=8,σ=1.84)move-ment.Thefindings can serve as a reliable baseline reference for assessing the population trends of this endangered felid species with future estimates.This study will provide context to contribute toward a better understanding of ecological factors shaping the distribution and abundance of snow leopards and the related conservation measures needed to sustain their long-term survival on the Tibetan Plateau.展开更多
虎作为世界上最为珍稀的野生动物之一,备受国际社会的关注。基于Web of Science数据库,采用文献计量学方法,分析了1992~2019年全球发表的虎研究论文量、居世界前10名的国家、机构、期刊和研究方向等情况。结果表明1992~2019年全球共发...虎作为世界上最为珍稀的野生动物之一,备受国际社会的关注。基于Web of Science数据库,采用文献计量学方法,分析了1992~2019年全球发表的虎研究论文量、居世界前10名的国家、机构、期刊和研究方向等情况。结果表明1992~2019年全球共发表的虎文献共867篇,年均发表论文31篇,且发文量呈逐年上升趋势;美国、印度和英国发文量居世界前3位,美国发文量最多,为378篇,占比43.6;印度野生动物研究所(Wildlife Institute of India)发文量最多(83篇),国际野生动物保护协会(Wildlife Conservation Society)和俄罗斯科学院(Russian Academy of Sciences)分别以75篇和35篇位居第2位和第3位。最有学术影响力的发文期刊是《Conservation Biology》,环境科学与生态学、动物学和生物多样性保护是虎研究的重点领域。未来虎的研究除在资源保护方面,还应注重遗传信息、机制等方面的研究。展开更多
In total, 177 of 245 terrestrial carnivores are described as solitary, and much of carnivore ecology is built on the assumptions that interactions between adult solitary carnivores are rare. We employed Global Positio...In total, 177 of 245 terrestrial carnivores are described as solitary, and much of carnivore ecology is built on the assumptions that interactions between adult solitary carnivores are rare. We employed Global Positioning System （GPS） technology and motion-triggered cameras to test predictions of land-tenure territoriality and the resource dispersion hypothesis in a territorial carnivore, the puma Puma concolor. We documented 89 independent GPS interactions, 60% of which occurred at puma kills （n=53）, 59 camera interactions, 11 （17%） of which captured courtship behaviors, and 5 other interactions （1 F-F, 3 M-F, and 1 M-M）. Mean minimum weekly contact rates were 5.5 times higher in winter, the season when elk Cervus elaphus were aggregated at lower elevations and during which puma courtship primarily occurred. In winter, contacts rates were 0.6_＋ 0.3 （standard devi- ation （SD）） interactions/week vs. 0.1 _＋ 0.1 （SD） interactions/week during summer. The preponder- ance of interactions at food sources supported the resource dispersion hypothesis, which predicts that resource fluxes can explain temporary social behaviors that do not result in any apparent benefits for the individuals involved. Conspecific tolerance is logical when a prey is so large that the predator that killed it cannot consume it entirely, and thus, the costs of tolerating a conspecific sharing the kill are less than the potential costs associated with defending it and being injured. Puma aggregations at kills numbered as high as 9, emphasizing the need for future research on what explains tolerance among solitary carnivores.展开更多
Poaching as well as loss of habitat and prey are identified as causes of tiger population declines.Although some studies have examined habitat requirements and prey availability,few studies have quantified cause-speci...Poaching as well as loss of habitat and prey are identified as causes of tiger population declines.Although some studies have examined habitat requirements and prey availability,few studies have quantified cause-specific mortality of tigers.We used cumulative incidence functions(CIFs)to quantify cause-specific mortality rates of tigers,expanding and refining earlier studies to assess the potential impact of a newly emerging disease.To quantify changes in tiger mortality over time,we re-examined data first collected by Goodrich et al.(2008;study period 1:1992–2004)as well as new telemetry data collected since January 2005(study period 2:2005–2012)using a total of 57 tigers(27 males and 30 females)monitored for an average of 747 days(range 26–4718 days).Across the entire study period(1992 to 2012)we found an estimated average annual survival rate of 0.75 for all tigers combined.Poaching was the primary cause of mortality during both study periods,followed by suspected poaching,distemper and natural/unknown causes.Since 2005,poaching mortality has remained relatively constant and,if combined with suspected poaching,may account for a loss of 17–19%of the population each year.Canine distemper virus(CDV)may be an additive form of mortality to the population,currently accounting for an additional 5%.Despite this relatively new source of mortality,poaching remains the main threat to Amur tiger survival and,therefore,population growth.展开更多
The snow leopard（Panthera uncial,Figure 1A）is a kind of beautiful big cat that is believed to originate on the Tibetan Plateau seven million years ago（Tseng et al.,2013）,and now inhabits alpine and subalpine zones...The snow leopard（Panthera uncial,Figure 1A）is a kind of beautiful big cat that is believed to originate on the Tibetan Plateau seven million years ago（Tseng et al.,2013）,and now inhabits alpine and subalpine zones in the remote and rugged mountains on the Tibetan Plateau and its surrounding mountain ranges.展开更多
As an apex predator the Amur tiger(Panthera tigris altaica)could play a pivotal role in maintaining the integrity of forest ecosystems in Northeast Asia.Due to habitat loss and harvest over the past century,tige...As an apex predator the Amur tiger(Panthera tigris altaica)could play a pivotal role in maintaining the integrity of forest ecosystems in Northeast Asia.Due to habitat loss and harvest over the past century,tigers rapidly declined in China and are now restricted to the Russian Far East and bordering habitat in nearby China.To facilitate restoration of the tiger in its historical range,reliable estimates of population size are essential to assess effectiveness of conservation interventions.Here we used camera trap data collected in Hunchun National Nature Reserve from April to June 2013 and 2014 to estimate tiger density and abundance using both maximum likelihood and Bayesian spatially explicit capture-recapture(SECR)methods.A minimum of 8 individuals were detected in both sample periods and the documentation of marking behavior and reproduction suggests the presence of a resident population.Using Bayesian SECR modeling within the 11400 km2 state space,density estimates were 0.33 and 0.40 individuals/100 km^(2) in 2013 and 2014,respectively,corresponding to an estimated abundance of 38 and 45 animals for this transboundary Sino-Russian population.In a maximum likelihood framework,we estimated densities of 0.30 and 0.24 individuals/100 km^(2) corresponding to abundances of 34 and 27,in 2013 and 2014,respectively.These density estimates are comparable to other published estimates for resident Amur tiger populations in the Russian Far East.This study reveals promising signs of tiger recovery in Northeast China,and demonstrates the importance of connectivity between the Russian and Chinese populations for recovering tigers in Northeast China.展开更多
With only 5%of the world’s wild tigers(Panthera tigris Linnaeus,1758)remaining since the last century,conservationists urgently need to know whether or not the management strategies currently being employed are effec...With only 5%of the world’s wild tigers(Panthera tigris Linnaeus,1758)remaining since the last century,conservationists urgently need to know whether or not the management strategies currently being employed are effectively protecting these tigers.This knowledge is contingent on the ability to reliably monitor tiger populations,or subsets,over space and time.In the this paper,we focus on the 2 seminal methodologies(camera trap and occupancy surveys)that have enabled the monitoring of tiger populations with greater confidence.Specifically,we:(i)describe their statistical theory and application in the field;(ii)discuss issues associated with their survey designs and state variable modeling;and,(iii)discuss their future directions.These methods have had an unprecedented influence on increasing statistical rigor within tiger surveys and,also,surveys of other carnivore species.Nevertheless,only 2 published camera trap studies have gone beyond single baseline assessments and actually monitored population trends.For low density tiger populations(e.g.<1 adult tiger/100 km2)obtaining sufficient precision for state variable estimates from camera trapping remains a challenge because of insufficient detection probabilities and/or sample sizes.Occupancy surveys have overcome this problem by redefining the sampling unit(e.g.grid cells and not individual tigers).Current research is focusing on developing spatially explicit capture-mark-recapture models and estimating abundance indices from landscape-scale occupancy surveys,as well as the use of genetic information for identifying and monitoring tigers.The widespread application of these monitoring methods in the field now enables complementary studies on the impact of the different threats to tiger populations and their response to varying management intervention.展开更多
Modern and paleoclimate changes may have altered species dynamics by shifting species’niche suitability over space and time.We analyze whether the current genetic structure and isolation of the two large American fel...Modern and paleoclimate changes may have altered species dynamics by shifting species’niche suitability over space and time.We analyze whether the current genetic structure and isolation of the two large American felids,jaguar(Panthera onca)and puma(Puma concolor),are mediated by changes in climatic suitability and connection routes over modern and paleoclimatic landscapes.We estimate species distribution under 5 climatic landscapes(modern,Holocene,last maximum glaciations[LMG],average suitability,and climatic instability)and correlate them with individuals’genetic isolation through causal modeling on a resemblance matrix.Both species exhibit genetic isolation patterns correlated with LMG climatic suitability,suggesting that these areas may have worked as“allele refuges.”However,the jaguar showed higher vulnerability to climate changes,responding to modern climatic suitability and connection routes,whereas the puma showed a continuous and gradual transition of genetic variation.Despite differential responsiveness to climate change,both species are subjected to the climatic effects on genetic configuration,which may make them susceptible to future climatic changes,since these are progressing faster and with higher intensity than changes in the paleoclimate.Thus,the effects of climatic changes should be considered in the design of conservation strategies to ensure evolutionary and demographic processes mediated by gene flow for both species.展开更多
基金funded by Panthera,Blue Moon Fund,Beijing Bishengyuan Co.Ltd.,and China Green Carbon Foundation.
文摘Knowledge of large carnivore population abundance is essential for wildlife management and conservation,but these data are often difficult to obtain in inherently low-density species.In particular,the snow leopard,Panthera uncia,an enigmatic cat occupying remote mountains in Central Asia,has received insufficient assessments of its population abundance because of logistical and methodological challenges.Here,we aimed to develop a robust density estimation of snow leopards based on 81 days of camera trapping within a contiguous and previously un-surveyed 1950 km^(2)area of habitat on the Tibetan Plateau(Mayue Township,Shenzha County,Xizang Autonomous Region,China).By applying spatially explicit capture-recapture models,we produced an estimate of 1.40(95%CI:1.06-1.84)individuals per 100 km^(2).Results also suggested sex-specific variation in the range of movement around activity centers,with male(N=10,σ=4.02)movement considerably greater than female(N=8,σ=1.84)move-ment.Thefindings can serve as a reliable baseline reference for assessing the population trends of this endangered felid species with future estimates.This study will provide context to contribute toward a better understanding of ecological factors shaping the distribution and abundance of snow leopards and the related conservation measures needed to sustain their long-term survival on the Tibetan Plateau.
文摘虎作为世界上最为珍稀的野生动物之一,备受国际社会的关注。基于Web of Science数据库,采用文献计量学方法,分析了1992~2019年全球发表的虎研究论文量、居世界前10名的国家、机构、期刊和研究方向等情况。结果表明1992~2019年全球共发表的虎文献共867篇,年均发表论文31篇,且发文量呈逐年上升趋势;美国、印度和英国发文量居世界前3位,美国发文量最多,为378篇,占比43.6;印度野生动物研究所(Wildlife Institute of India)发文量最多(83篇),国际野生动物保护协会(Wildlife Conservation Society)和俄罗斯科学院(Russian Academy of Sciences)分别以75篇和35篇位居第2位和第3位。最有学术影响力的发文期刊是《Conservation Biology》,环境科学与生态学、动物学和生物多样性保护是虎研究的重点领域。未来虎的研究除在资源保护方面,还应注重遗传信息、机制等方面的研究。
文摘In total, 177 of 245 terrestrial carnivores are described as solitary, and much of carnivore ecology is built on the assumptions that interactions between adult solitary carnivores are rare. We employed Global Positioning System （GPS） technology and motion-triggered cameras to test predictions of land-tenure territoriality and the resource dispersion hypothesis in a territorial carnivore, the puma Puma concolor. We documented 89 independent GPS interactions, 60% of which occurred at puma kills （n=53）, 59 camera interactions, 11 （17%） of which captured courtship behaviors, and 5 other interactions （1 F-F, 3 M-F, and 1 M-M）. Mean minimum weekly contact rates were 5.5 times higher in winter, the season when elk Cervus elaphus were aggregated at lower elevations and during which puma courtship primarily occurred. In winter, contacts rates were 0.6_＋ 0.3 （standard devi- ation （SD）） interactions/week vs. 0.1 _＋ 0.1 （SD） interactions/week during summer. The preponder- ance of interactions at food sources supported the resource dispersion hypothesis, which predicts that resource fluxes can explain temporary social behaviors that do not result in any apparent benefits for the individuals involved. Conspecific tolerance is logical when a prey is so large that the predator that killed it cannot consume it entirely, and thus, the costs of tolerating a conspecific sharing the kill are less than the potential costs associated with defending it and being injured. Puma aggregations at kills numbered as high as 9, emphasizing the need for future research on what explains tolerance among solitary carnivores.
文摘Poaching as well as loss of habitat and prey are identified as causes of tiger population declines.Although some studies have examined habitat requirements and prey availability,few studies have quantified cause-specific mortality of tigers.We used cumulative incidence functions(CIFs)to quantify cause-specific mortality rates of tigers,expanding and refining earlier studies to assess the potential impact of a newly emerging disease.To quantify changes in tiger mortality over time,we re-examined data first collected by Goodrich et al.(2008;study period 1:1992–2004)as well as new telemetry data collected since January 2005(study period 2:2005–2012)using a total of 57 tigers(27 males and 30 females)monitored for an average of 747 days(range 26–4718 days).Across the entire study period(1992 to 2012)we found an estimated average annual survival rate of 0.75 for all tigers combined.Poaching was the primary cause of mortality during both study periods,followed by suspected poaching,distemper and natural/unknown causes.Since 2005,poaching mortality has remained relatively constant and,if combined with suspected poaching,may account for a loss of 17–19%of the population each year.Canine distemper virus(CDV)may be an additive form of mortality to the population,currently accounting for an additional 5%.Despite this relatively new source of mortality,poaching remains the main threat to Amur tiger survival and,therefore,population growth.
文摘The snow leopard（Panthera uncial,Figure 1A）is a kind of beautiful big cat that is believed to originate on the Tibetan Plateau seven million years ago（Tseng et al.,2013）,and now inhabits alpine and subalpine zones in the remote and rugged mountains on the Tibetan Plateau and its surrounding mountain ranges.
基金supported by grants from the Natural Science Foundation of China(31270567,31210103911,31421063,31200410 and 31470566)the National Scientific and Technical Foundation Project of China(2012FY112000).
文摘As an apex predator the Amur tiger(Panthera tigris altaica)could play a pivotal role in maintaining the integrity of forest ecosystems in Northeast Asia.Due to habitat loss and harvest over the past century,tigers rapidly declined in China and are now restricted to the Russian Far East and bordering habitat in nearby China.To facilitate restoration of the tiger in its historical range,reliable estimates of population size are essential to assess effectiveness of conservation interventions.Here we used camera trap data collected in Hunchun National Nature Reserve from April to June 2013 and 2014 to estimate tiger density and abundance using both maximum likelihood and Bayesian spatially explicit capture-recapture(SECR)methods.A minimum of 8 individuals were detected in both sample periods and the documentation of marking behavior and reproduction suggests the presence of a resident population.Using Bayesian SECR modeling within the 11400 km2 state space,density estimates were 0.33 and 0.40 individuals/100 km^(2) in 2013 and 2014,respectively,corresponding to an estimated abundance of 38 and 45 animals for this transboundary Sino-Russian population.In a maximum likelihood framework,we estimated densities of 0.30 and 0.24 individuals/100 km^(2) corresponding to abundances of 34 and 27,in 2013 and 2014,respectively.These density estimates are comparable to other published estimates for resident Amur tiger populations in the Russian Far East.This study reveals promising signs of tiger recovery in Northeast China,and demonstrates the importance of connectivity between the Russian and Chinese populations for recovering tigers in Northeast China.
文摘With only 5%of the world’s wild tigers(Panthera tigris Linnaeus,1758)remaining since the last century,conservationists urgently need to know whether or not the management strategies currently being employed are effectively protecting these tigers.This knowledge is contingent on the ability to reliably monitor tiger populations,or subsets,over space and time.In the this paper,we focus on the 2 seminal methodologies(camera trap and occupancy surveys)that have enabled the monitoring of tiger populations with greater confidence.Specifically,we:(i)describe their statistical theory and application in the field;(ii)discuss issues associated with their survey designs and state variable modeling;and,(iii)discuss their future directions.These methods have had an unprecedented influence on increasing statistical rigor within tiger surveys and,also,surveys of other carnivore species.Nevertheless,only 2 published camera trap studies have gone beyond single baseline assessments and actually monitored population trends.For low density tiger populations(e.g.<1 adult tiger/100 km2)obtaining sufficient precision for state variable estimates from camera trapping remains a challenge because of insufficient detection probabilities and/or sample sizes.Occupancy surveys have overcome this problem by redefining the sampling unit(e.g.grid cells and not individual tigers).Current research is focusing on developing spatially explicit capture-mark-recapture models and estimating abundance indices from landscape-scale occupancy surveys,as well as the use of genetic information for identifying and monitoring tigers.The widespread application of these monitoring methods in the field now enables complementary studies on the impact of the different threats to tiger populations and their response to varying management intervention.
基金supported by project CGL2010-16902 of the Spanish Ministry of Research and Innovation,project CGL2013-46026-P of Ministerio de Economía,Industria y Competitividad,excellence project RNM2300 of Junta de Andalucía(Spain),the Formación de Profe-sorado Universitario fellowship#AP2010-5373 from the Spanish Ministry of Education,and by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil(CAPES)(Finance Code 001).L.P.C.has a fellowship from Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq).M.Z.is supported by CAPES(grant number 88887.478136/2020-00)through the Program of National Cooperation in the Amazon(Programa Nacional De Cooperação Acadêmica na Amazônia).
文摘Modern and paleoclimate changes may have altered species dynamics by shifting species’niche suitability over space and time.We analyze whether the current genetic structure and isolation of the two large American felids,jaguar(Panthera onca)and puma(Puma concolor),are mediated by changes in climatic suitability and connection routes over modern and paleoclimatic landscapes.We estimate species distribution under 5 climatic landscapes(modern,Holocene,last maximum glaciations[LMG],average suitability,and climatic instability)and correlate them with individuals’genetic isolation through causal modeling on a resemblance matrix.Both species exhibit genetic isolation patterns correlated with LMG climatic suitability,suggesting that these areas may have worked as“allele refuges.”However,the jaguar showed higher vulnerability to climate changes,responding to modern climatic suitability and connection routes,whereas the puma showed a continuous and gradual transition of genetic variation.Despite differential responsiveness to climate change,both species are subjected to the climatic effects on genetic configuration,which may make them susceptible to future climatic changes,since these are progressing faster and with higher intensity than changes in the paleoclimate.Thus,the effects of climatic changes should be considered in the design of conservation strategies to ensure evolutionary and demographic processes mediated by gene flow for both species.
