The North Chinese leopard(Panthera pardus japonensis),the least-known big cat,disappeared in most historical range for decades,following the development of modern civilization.Unfortunately,we have scarce knowledge ab...The North Chinese leopard(Panthera pardus japonensis),the least-known big cat,disappeared in most historical range for decades,following the development of modern civilization.Unfortunately,we have scarce knowledge about the status of this big cat so far,apart from anecdotal reports.In this study,we investigated density,distribution,and habitat use of the leopard,the apex predator,in a complex forest landscape in the Loess Plateau.We used a camera-trapping network to obtain population estimates for leopards over 2 years through spatially explicit capture-recapture models.Our results,based on maximum likelihood and Bayesian/MCMC methods,reveal that the largest wild population of the leopard was found widely distributed in remnant forests in central Loess plateau.The population is increasing in our study area,and the density of leopards(1.70(SE=0.48)−2.40(SE=0.67)/100 km^(2))is higher than other areas of China.According to the analysis of 2 seasonal occupancy models,prey species drive partially the leopard habitat use,predicting that the big cat thrives from the recovery of prey community.However,human disturbances,especially oil wells,seem to have negative impacts on the habitat use of leopards.Specifically,it is necessary to have joint efforts by the government and researchers to improve human disturbances management and prey species population density,as well as strengthen the investment in research on the North Chinese leopard,which could all further strengthen protection ability and ensure the long-term survival of this species.展开更多
Insect diversity and abundance are in drastic decline worldwide,but quantifying insect populations to better conserve them is a difficult task.Mark-release-recapture(MRR)is widely used as an ecological indicator for i...Insect diversity and abundance are in drastic decline worldwide,but quantifying insect populations to better conserve them is a difficult task.Mark-release-recapture(MRR)is widely used as an ecological indicator for insect populations,but the accuracy of MRR estimates can vary with factors such as spatial scale,sampling effort and models of inference.We conducted a 3-year MRR study of B.thaidina in Yanzigou valley,Mt.Gongga but failed to obtain sufficient data for a robust population estimate.This prompted us to integrate B.thaidina life history information to parameterize agent-based models and evaluate the conditions under which successful MRR studies could be conducted.We evaluated:(1)the performance of MRR models under different landscape types,and(2)the influence of experimental design on the accuracy and variance of MRR-based estimates.Our simulations revealed systematic underestimates of true population parameters by MRR models when sampling effort was insufficient.In a total of 2772 simulations,subjective decisions in sampling protocol(e.g.,frequency,number of sampling locations,use of spatially explicit models,type of estimands)accounted for nearly half of the variation in estimates.We conclude that MRR-based estimates could be improved with the addition of more field-specific parameters.展开更多
The endangered Asian tapir(Tapirus indicus)is threatened by large-scale habitat loss,forest fragmentation and increased hunting pressure.Conservation planning for this species,however,is hampered by a severe paucity o...The endangered Asian tapir(Tapirus indicus)is threatened by large-scale habitat loss,forest fragmentation and increased hunting pressure.Conservation planning for this species,however,is hampered by a severe paucity of information on its ecology and population status.We present the first Asian tapir population density estimate from a camera trapping study targeting tigers in a selectively logged forest within Peninsular Malaysia using a spatially explicit capture-recapture maximum likelihood based framework.With a trap effort of 2496 nights,17 individuals were identified corresponding to a density(standard error)estimate of 9.49(2.55)adult ta-pirs/100 km2.Although our results include several caveats,we believe that our density estimate still serves as an important baseline to facilitate the monitoring of tapir population trends in Peninsular Malaysia.Our study also highlights the potential of extracting vital ecological and population information for other cryptic individual-ly identifiable animals from tiger-centric studies,especially with the use of a spatially explicit capture-recapture maximum likelihood based framework.展开更多
基金supported by grant from the National Natural Sci-ence Foundation of China(31670537,31200410)the National Scientific and Technical Foundation Project of China(2012FY112000)Cyrus Tang Foundation(2016),and the Doctoral Fund of Ministry of Education of China(2019M653714).
文摘The North Chinese leopard(Panthera pardus japonensis),the least-known big cat,disappeared in most historical range for decades,following the development of modern civilization.Unfortunately,we have scarce knowledge about the status of this big cat so far,apart from anecdotal reports.In this study,we investigated density,distribution,and habitat use of the leopard,the apex predator,in a complex forest landscape in the Loess Plateau.We used a camera-trapping network to obtain population estimates for leopards over 2 years through spatially explicit capture-recapture models.Our results,based on maximum likelihood and Bayesian/MCMC methods,reveal that the largest wild population of the leopard was found widely distributed in remnant forests in central Loess plateau.The population is increasing in our study area,and the density of leopards(1.70(SE=0.48)−2.40(SE=0.67)/100 km^(2))is higher than other areas of China.According to the analysis of 2 seasonal occupancy models,prey species drive partially the leopard habitat use,predicting that the big cat thrives from the recovery of prey community.However,human disturbances,especially oil wells,seem to have negative impacts on the habitat use of leopards.Specifically,it is necessary to have joint efforts by the government and researchers to improve human disturbances management and prey species population density,as well as strengthen the investment in research on the North Chinese leopard,which could all further strengthen protection ability and ensure the long-term survival of this species.
基金supported by a graduate fellowship from Harvard University Department of Organismic and Evolutionary Biology,as well as a Joan Mosenthal DeWind Award in Lepidoptera conservation from the Xerces Society(2017)for studying the spatial ecology of butterflies in Yanzigou valleyZW and AJ were supported by a Rufford Small Grant(2016)to work on the conservation of B.thaidinaAspects of the modeling approach used in this research were supported by a grant from the Harvard Global Institute(HG1)to YL,ZW and NEP.
文摘Insect diversity and abundance are in drastic decline worldwide,but quantifying insect populations to better conserve them is a difficult task.Mark-release-recapture(MRR)is widely used as an ecological indicator for insect populations,but the accuracy of MRR estimates can vary with factors such as spatial scale,sampling effort and models of inference.We conducted a 3-year MRR study of B.thaidina in Yanzigou valley,Mt.Gongga but failed to obtain sufficient data for a robust population estimate.This prompted us to integrate B.thaidina life history information to parameterize agent-based models and evaluate the conditions under which successful MRR studies could be conducted.We evaluated:(1)the performance of MRR models under different landscape types,and(2)the influence of experimental design on the accuracy and variance of MRR-based estimates.Our simulations revealed systematic underestimates of true population parameters by MRR models when sampling effort was insufficient.In a total of 2772 simulations,subjective decisions in sampling protocol(e.g.,frequency,number of sampling locations,use of spatially explicit models,type of estimands)accounted for nearly half of the variation in estimates.We conclude that MRR-based estimates could be improved with the addition of more field-specific parameters.
文摘The endangered Asian tapir(Tapirus indicus)is threatened by large-scale habitat loss,forest fragmentation and increased hunting pressure.Conservation planning for this species,however,is hampered by a severe paucity of information on its ecology and population status.We present the first Asian tapir population density estimate from a camera trapping study targeting tigers in a selectively logged forest within Peninsular Malaysia using a spatially explicit capture-recapture maximum likelihood based framework.With a trap effort of 2496 nights,17 individuals were identified corresponding to a density(standard error)estimate of 9.49(2.55)adult ta-pirs/100 km2.Although our results include several caveats,we believe that our density estimate still serves as an important baseline to facilitate the monitoring of tapir population trends in Peninsular Malaysia.Our study also highlights the potential of extracting vital ecological and population information for other cryptic individual-ly identifiable animals from tiger-centric studies,especially with the use of a spatially explicit capture-recapture maximum likelihood based framework.
