Weak spatiotemporal response of prey to predation risk in a freely interacting system
Weak spatiotemporal response of prey to predation risk in a freely interacting system
复制标题
DOI：
10.1111/1365-2656.12968
复制
发表时间：
2020-01-01
影响因子：
4.8
通讯作者：
MacNulty, Daniel R.
中科院分区：
文献类型：
--
作者：
Cusack, Jeremy J.;Kohl, Michel T.;MacNulty, Daniel R.
猎物空间的积极利用程度如何最大限度地降低捕食风险仍然引发争议。阻碍达成共识的方法论原因包括对捕食风险的测量不一致、测量反应的时空尺度存在偏差以及缺乏稳健的零预期。我们在美国黄石北部冬季对成年雌性麋鹿（Cervus elaphus）对狼（Canis lupus）捕食风险的时空反应进行了全面分析，解决了所有三个挑战。我们量化了带 GPS 项圈的麋鹿冬季栖息地和三种捕食风险指标之间的空间重叠：狼空间利用的强度、被狼杀死的麋鹿的分布和植被开放度。我们还评估了麋鹿在一天中的几个小时内是否会改变对具有或多或少捕食风险特征的区域的使用，并估计了麋鹿和狼群同时轨迹之间的遭遇率。如果麋鹿的运动是随机的，我们使用零模型方法并参考捕食风险来确定观测值是否显着低于预期。尽管一小部分麋鹿确实表现出在一天中的特定时间尽量减少使用开放植被的倾向，但总体而言，我们强调雌性麋鹿对黄石北部狼捕食风险的时空反应明显缺乏。我们的结果表明，捕食者与猎物的相互作用可能并不总是导致强烈的时空回避模式。
The extent to which prey space use actively minimizes predation risk continues to ignite controversy. Methodological reasons that have hindered consensus include inconsistent measurements of predation risk, biased spatiotemporal scales at which responses are measured and lack of robust null expectations. We addressed all three challenges in a comprehensive analysis of the spatiotemporal responses of adult female elk (Cervus elaphus) to the risk of predation by wolves (Canis lupus) during winter in northern Yellowstone, USA. We quantified spatial overlap between the winter home ranges of GPS-collared elk and three measures of predation risk: the intensity of wolf space use, the distribution of wolf-killed elk and vegetation openness. We also assessed whether elk varied their use of areas characterized by more or less predation risk across hours of the day, and estimated encounter rates between simultaneous elk and wolf pack trajectories. We determined whether observed values were significantly lower than expected if elk movements were random with reference to predation risk using a null model approach. Although a small proportion of elk did show a tendency to minimize use of open vegetation at specific times of the day, overall we highlight a notable absence of spatiotemporal response by female elk to the risk of predation posed by wolves in northern Yellowstone. Our results suggest that predator-prey interactions may not always result in strong spatiotemporal patterns of avoidance.