Isbell Lynne A
Animal Behavior Group, Department of Anthropology, University of California, Davis.
Am J Primatol. 1990;21(1):41-52. doi: 10.1002/ajp.1350210105.
A substantial increase in mortality, due mainly to predation, occurred during 1987 in a population of vervet monkeys (Cercopithecus aethiops) studied from 1977 to 1989 in Amboseli National Park, Kenya. It has been shown that vervets moving into new and unfamiliar habitats are more at risk from predation. However, this does not entirely explain the increase in predation in 1987 because predation decreased after 1987 while movement into new areas continued. An increase in leopard alarm calls relative to previous years in four of five groups, and an association between disappearances and leopard alarm calls given by vervets in the same four groups, suggest that leopards, a main predator of vervets, accounted for the increase in mortality. The vervets' increased vulnerability to leopard predation in 1987 did not appear to be related either directly or indirectly to continued habitat deterioration because 1) mortality rates after 1987 decreased to pre-1987 levels and 2) the vervets' behavior did not appear to change to make them more vulnerable than in previous years. The increased vulnerability appeared to be due in part to an increase in the presence of leopards. However, it is unclear why predator presence temporarily increased.
1987年，在肯尼亚安博塞利国家公园于1977年至1989年期间研究的一群黑长尾猴（草原猴）中，主要由于捕食导致死亡率大幅上升。研究表明，迁入新的和不熟悉栖息地的黑长尾猴面临更大的被捕食风险。然而，这并不能完全解释1987年捕食率的上升，因为1987年之后捕食率下降了，而迁入新区域的情况仍在继续。五个群体中有四个群体相对于前几年豹的警报叫声增加，并且在同一四个群体中黑长尾猴发出的消失事件与豹的警报叫声之间存在关联，这表明作为黑长尾猴主要捕食者的豹是死亡率上升的原因。1987年黑长尾猴对豹捕食的易感性增加似乎与栖息地持续恶化没有直接或间接关系，因为：1）1987年之后的死亡率降至1987年之前的水平；2）黑长尾猴的行为似乎没有改变，使它们比前几年更容易受到伤害。易感性增加似乎部分归因于豹的出现增加。然而，目前尚不清楚为什么捕食者的出现会暂时增加。
