Predation rate, prey preference and predator switching: experiments on voles and weasels
Predation rate, prey preference and predator switching: experiments on voles and weasels
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DOI：
10.1034/j.1600-0706.2003.12264.x
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发表时间：
2003-06
期刊：
影响因子：
3.4
通讯作者：
J. Sundell;J. Eccard;R. Tiilikainen;H. Ylönen
中科院分区：
文献类型：
--
作者：
J. Sundell;J. Eccard;R. Tiilikainen;H. Ylönen
在野外大型围栏内，研究了白鼬（Mustela nivalis nivalis）对北方环境中最常见的两种猎物--河岸田鼠（Clethrionomys glareolus）和田鼠（Microtus agrestis）的捕食率和猎物选择。我们还在实验室研究了黄鼠狼对这两种气味的反应。封闭实验进行了使用恒定的田鼠密度（16田鼠/公顷），但不同的相对丰度的两个物种。黄鼬对河岸田鼠的捕食率较高，且雄性的捕食率高于雌性。雌鼠杀死的猎物种类多得不成比例，但它们更喜欢河岸田鼠，而不是田野田鼠。总体而言，捕食率也增加了丰富的银行田鼠。因此，我们的研究结果是在协议与早期的实验室结果显示偏好银行田鼠，即使没有内在的偏好，无论是物种的气味，在我们的实验室研究中观察到。我们建议，最少的黄鼠狼狩猎根据猎物的可用性，猎物聚集和狩猎栖息地的适宜性，这会导致观察到的依赖性最少的黄鼠狼对田鼠和强调的作用，在田鼠-黄鼠狼的相互作用，在循环田鼠种群的田鼠。此外，我们的研究结果表明，黄鼠狼的捕食可能会促进共存的两种田鼠通过捕食者切换，它可能会导致观察到的同步性田鼠物种之间的动态。
We studied the predation rate and prey selection of the least weasel (Mustela nivalis nivalis) on its two most common prey species in boreal environments, the bank vole (Clethrionomys glareolus) and the field vole (Microtus agrestis), in large outdoor enclosures. We also studied the response of weasels to odours of the two species in the laboratory. The enclosure experiment was conducted using constant vole densities (16 voles/ha) but with varying relative abundance of the two species. Weasels showed higher predation rates on bank voles, and males had higher predation rate than females. Females killed disproportionately more of the more abundant prey species, but they preferred bank voles to field voles when both were equally available. Overall, the predation rate also increased with increasing abundance of bank voles. Therefore our results are in agreement with earlier laboratory results showing preference for bank voles, even if no intrinsic preference for odours of either species was observed in our laboratory study. We suggest that the least weasel hunts according to prey availability, prey aggregation and suitability of hunting habitat, and that this causes the observed dependence of least weasels on field voles and emphasises the role of the field vole in the vole-weasel interaction in cyclic vole populations. Furthermore, our results suggest that predation by weasels may facilitate the coexistence of the two vole species via predator switching, and that it may cause the observed synchrony in dynamics between vole species.