甘肃祁连山脉雪豹及其同域分布大型食肉动物时间生态位关系

Temporal niche relationship between snow leopard(Panthera uncia)and its sympatric large carnivores in Qilian Mountains,Gansu Province

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)。

Large mammalian carnivores are at the top of the food chain and nutritional level,and they play an important role in maintaining the stability of ecosystem structure and function.Exploring the interspecific interaction and coexistence mechanism of large carnivores is of great significance to understanding how biotic communities assemble,species population dynamics,and endangered species conservation and management.In this study,we seleted the Yanchiwan National Nature Reserve in the west of Qilian Mountains,Gansu Province as our study area.We collected temporal data of snow leopards(Panthera uncia)and their sympatric large carnivores from a camera-trapping survey in the alpine ecosystem and conducted kernel density estimation and coefficient of overlap to explore temporal niche differentiation.We found that the daily activity patterns of snow leopards showed a sub-peak and a peak at 04:00–08:00 and 16:00–20:00,respectively,indicating that snow leopards tended to be crepuscular.The sub-peak and the highest peak of the daily activity patterns of brown bears(Ursus arctos)are from 03:00 to 05:00 and from 19:00 to 21:00 respectively,which are more nocturnal.Dhole(Cuon alpinus)has the highest peak and sub-peak from 06:00 to 10:00,which are concentrated in the daytime and mainly active in the morning,making it a typical diurnal animal.The daily activity patterns of lynx(Lynx lynx)and wolf(Canis lupus)were both bimodal.The two activity peaks of lynx are 01:00-03:00 and 18:00-20:00,which are more nocturnal,while the two activity peaks of wolves are about 09:00-11:00 and 18:00-19:00,which are more diurnal.The overlap of daily activity patterns of snow leopard and wolf(Δ1=0.70),snow leopard and lynx(Δ1=0.78),and snow leopard and brown bear(Δ1=0.82)were higher,while snow leopard and dhole(Δ1=0.39)showed low overlap of daily activity pattern.The results preliminarily revealed the temporal niche relationship between the snow leopard and its sympatric large carnivores and,provide basic information for a further in-depth understanding of the coexistence mechanism of large carnivores in the alpine ecosystem.