Minimizing predation risk in a landscape of multiple predators: effects on the spatial distribution of African ungulates.
Minimizing predation risk in a landscape of multiple predators: effects on the spatial distribution of African ungulates.
复制标题
最大限度地减少多种捕食者景观中的捕食风险：对非洲有蹄类动物空间分布的影响。
作者：
M. Thaker;A. Vanak;Cailey R. Owen;Monika Ogden;S. M. Niemann;R. Slotow
研究集中在单一的捕食者-猎物的相互作用可能是不够的理解antipredator反应在多捕食者系统。然而，仍然是一个普遍缺乏信息的策略，猎物，以尽量减少捕食风险，从多个捕食者在景观水平。在这里，我们研究了7个非洲有蹄类动物物种的分布在围栏Karongwe游戏保护区（KGR），南非，作为一个功能的捕食风险从所有大型食肉动物物种（狮子，豹，猎豹，非洲野狗，和斑点鬣狗）。使用观察到的杀死数据，我们产生了有蹄类特定的相对捕食风险和栖息地的风险预测。为了确定有蹄类动物如何在景观水平上最大限度地减少捕食风险，我们明确测试了五个假设，包括战略，减少遇到捕食者的概率，和被杀的概率。所有的有蹄类动物都避免了危险的栖息地，大多数选择了更安全的栖息地，从而降低了它们被杀死的可能性。为了减少遇到捕食者的可能性，大多数较小的猎物物种（黑斑羚，疣猪，水羚，捻角羚）避免了所有捕食者的空间使用，而较大的物种（角马，斑马，长颈鹿）只避免狮子和豹空间使用高的地区。捕食者空间利用的回避强度一般不对应于这些捕食者的相对捕食威胁。相反，有蹄类动物使用了一种更简单的行为规则，即避开坐着追逐的捕食者（狮子和豹子）的活动区域，而不是那些奔跑的捕食者（猎豹和非洲野狗）。一般来说，生境的选择和回避比回避捕食者活动区更强。我们希望类似的决策规则，以推动有蹄类动物在其他非洲热带草原和其他多捕食者系统的分布格局，特别是在捕食者在他们的狩猎模式不同。
Studies that focus on single predator-prey interactions can be inadequate for understanding antipredator responses in multi-predator systems. Yet there is still a general lack of information about the strategies of prey to minimize predation risk from multiple predators at the landscape level. Here we examined the distribution of seven African ungulate species in the fenced Karongwe Game Reserve (KGR), South Africa, as a function of predation risk from all large carnivore species (lion, leopard, cheetah, African wild dog, and spotted hyena). Using observed kill data, we generated ungulate-specific predictions of relative predation risk and of riskiness of habitats. To determine how ungulates minimize predation risk at the landscape level, we explicitly tested five hypotheses consisting of strategies that reduce the probability of encountering predators, and the probability of being killed. All ungulate species avoided risky habitats, and most selected safer habitats, thus reducing their probability of being killed. To reduce the probability of encountering predators, most of the smaller prey species (impala, warthog, waterbuck, kudu) avoided the space use of all predators, while the larger species (wildebeest, zebra, giraffe) only avoided areas where lion and leopard space use were high. The strength of avoidance for the space use of predators generally did not correspond to the relative predation threat from those predators. Instead, ungulates used a simpler behavioral rule of avoiding the activity areas of sit-and-pursue predators (lion and leopard), but not those of cursorial predators (cheetah and African wild dog). In general, selection and avoidance of habitats was stronger than avoidance of the predator activity areas. We expect similar decision rules to drive the distribution pattern of ungulates in other African savannas and in other multi-predator systems, especially where predators differ in their hunting modes.