群落内多物种如何共存是群落生态学和生物多样性研究的核心内容之一。经典物种共存理论强调物种之间的生态位分化,侧重于物种对环境的需求,Hutchinson(1957)提出超体积生态位概念,认为物种适合度是由多个因素共同决定,即物种只有在满足...群落内多物种如何共存是群落生态学和生物多样性研究的核心内容之一。经典物种共存理论强调物种之间的生态位分化,侧重于物种对环境的需求,Hutchinson(1957)提出超体积生态位概念,认为物种适合度是由多个因素共同决定,即物种只有在满足其生态位需求的多维空间,才能在没有个体迁入的条件下持续生存;极限相似性假说假定能够稳定共存的两个物种之间的相似性程度存在一个上限,超过此上限,物种间即发生竞争排除(MacArthur and Levins,1967)。展开更多
豺(Cuon alpinus)历史上广泛分布于东亚、南亚以及中亚地区,是其所在生态系统中的顶级捕食者(apex predator),在维持生态系统结构完整和功能稳定中具有重要的作用(Ripple et al.,2014;Kamler,2015)。目前,豺是全球最濒危的犬科动物之一...豺(Cuon alpinus)历史上广泛分布于东亚、南亚以及中亚地区,是其所在生态系统中的顶级捕食者(apex predator),在维持生态系统结构完整和功能稳定中具有重要的作用(Ripple et al.,2014;Kamler,2015)。目前,豺是全球最濒危的犬科动物之一。据估计,豺在全球的分布范围已经缩减了82.4%(Wolf and Ripple,2017),目前种群总数仅为4500~10500只(Kamleretal.,2015)。展开更多
Resource depletion exerts opposing pressures on co-occurring consumers to expand diets while limiting overlap with competitors.Using foraging theory as a framework,we tested the effects of prey availability on diet sp...Resource depletion exerts opposing pressures on co-occurring consumers to expand diets while limiting overlap with competitors.Using foraging theory as a framework,we tested the effects of prey availability on diet spe-cialization and overlap among competing Asian predators:dhole,leopard,and tiger.We used scat analysis from a prey-poor site,combined with a quantitative synthesis of 40 other diet studies,to determine biomass of different prey types consumed by each predator.We then assessed diet composition in relation to prey density,and compared diet breadth and overlap between prey-poor and prey-rich sites.In prey rich areas,all three predators specialized on energetically profitable medium and large ungulates(>30 kg),resulting in narrow,overlapping niches.Each predator shifted toward less profitable small-bodied prey(≤30 kg)as preferred ungulates declined,whereas con-sumption of preferred ungulates was unrelated to small prey abundance,as predicted by foraging theory.Diet breadths doubled under prey depletion(except leopard),but overlap declined as diets diverged via species-specific traits that facilitated capture of different types of alternative prey.Asia’s apex predators adapt similarly to depletion of mutually preferred ungulates by switching to more numerous but less profitable small prey.Yet they can also partition a depleted prey base through intrinsic niche differences,thereby avoiding competitive exclusion.Our find-ings illuminate the stabilizing properties of adaptive foraging and niche differences in ecological communities,and provide insights into the behavior and resilience of Asia’s endangered apex predators in response to prey depletion in the heavily poached forests of this region.展开更多
文摘群落内多物种如何共存是群落生态学和生物多样性研究的核心内容之一。经典物种共存理论强调物种之间的生态位分化,侧重于物种对环境的需求,Hutchinson(1957)提出超体积生态位概念,认为物种适合度是由多个因素共同决定,即物种只有在满足其生态位需求的多维空间,才能在没有个体迁入的条件下持续生存;极限相似性假说假定能够稳定共存的两个物种之间的相似性程度存在一个上限,超过此上限,物种间即发生竞争排除(MacArthur and Levins,1967)。
文摘豺(Cuon alpinus)历史上广泛分布于东亚、南亚以及中亚地区,是其所在生态系统中的顶级捕食者(apex predator),在维持生态系统结构完整和功能稳定中具有重要的作用(Ripple et al.,2014;Kamler,2015)。目前,豺是全球最濒危的犬科动物之一。据估计,豺在全球的分布范围已经缩减了82.4%(Wolf and Ripple,2017),目前种群总数仅为4500~10500只(Kamleretal.,2015)。
基金funded by Fran-cois and Sheila Brutsch,WWF Germany,WWF France,WWF US,WWF Sweden,WWF Denmark,WWF Aus-tria,The Rhino and Tiger Conservation Fund(U.S.Fish and Wildlife Service),and Keidanren Nature Conserva-tion Fund.
文摘Resource depletion exerts opposing pressures on co-occurring consumers to expand diets while limiting overlap with competitors.Using foraging theory as a framework,we tested the effects of prey availability on diet spe-cialization and overlap among competing Asian predators:dhole,leopard,and tiger.We used scat analysis from a prey-poor site,combined with a quantitative synthesis of 40 other diet studies,to determine biomass of different prey types consumed by each predator.We then assessed diet composition in relation to prey density,and compared diet breadth and overlap between prey-poor and prey-rich sites.In prey rich areas,all three predators specialized on energetically profitable medium and large ungulates(>30 kg),resulting in narrow,overlapping niches.Each predator shifted toward less profitable small-bodied prey(≤30 kg)as preferred ungulates declined,whereas con-sumption of preferred ungulates was unrelated to small prey abundance,as predicted by foraging theory.Diet breadths doubled under prey depletion(except leopard),but overlap declined as diets diverged via species-specific traits that facilitated capture of different types of alternative prey.Asia’s apex predators adapt similarly to depletion of mutually preferred ungulates by switching to more numerous but less profitable small prey.Yet they can also partition a depleted prey base through intrinsic niche differences,thereby avoiding competitive exclusion.Our find-ings illuminate the stabilizing properties of adaptive foraging and niche differences in ecological communities,and provide insights into the behavior and resilience of Asia’s endangered apex predators in response to prey depletion in the heavily poached forests of this region.
