Foraging strategy mediates ectotherm predator–prey responses to climate warming
Foraging strategy mediates ectotherm predator–prey responses to climate warming
复制标题
觅食策略调节变温掠食者-猎物对气候变暖的反应
DOI：
10.1002/ecy.3146
复制
发表时间：
2020
期刊：
影响因子：
4.8
通讯作者：
Zarnetske, Phoebe L.
中科院分区：
文献类型：
--
作者：
Twardochleb, Laura A.;Treakle, Tyler C.;Zarnetske, Phoebe L.
气候变暖和物种特征相互作用，影响捕食者的表现，包括个体摄食和生长速度。然而，捕食者觅食策略的一个重要特征的影响在很大程度上是未知的。我们研究了捕食者对两种外温性捕食者的捕食策略与温度的相互作用。这两种捕食者是一种活跃的捕食者--背水型捕食者波纹夜蛾，以及一种坐以待毙的捕食者--斑点天敌Enallagma Annexum。在一系列跨越温度梯度的捕食者-猎物实验中，我们测量了捕食者对活跃的猎物物种--浮游动物--脉冲大型水蚤的摄食率，捕食者的生长速度，以及影响捕食者摄食的机制：捕食者和猎物的身体速度(这里测量的是游泳速度)，猎物遇到率，捕获成功率，攻击率和处理时间。总体而言，气候变暖通过改变捕食者功能反应的每个组成部分，增加了这两种捕食者的摄食率。我们发现，猎物的游泳速度随着温度的升高而显著增加。主动捕食者的游泳速度也随着温度的升高而增加，捕食者和猎物游泳速度的增加共同导致了温度升高时主动捕食者遇到猎物的几率增加了一倍。相比之下，坐等的捕食者遇到猎物的几率随着温度的上升而增加四倍，这是由于猎物游泳速度加快的结果。同时，在高温下，猎物游动速度的增加与捕食者捕获成功率的下降有关，而坐以待毙的捕食者捕获成功率随着温度的升高而略有增加。我们提供了一些最初的证据，证明觅食特征在气候变暖对捕食者行为的间接影响中起到了中介作用。了解特征如何影响物种对气候变暖的反应，可以澄清气候变化将如何影响物种的整个功能群体。
Climate warming and species traits interact to influence predator performance, including individual feeding and growth rates. However, the effects of an important trait—predator foraging strategy—are largely unknown. We investigated the interactions between predator foraging strategy and temperature on two ectotherm predators: an active predator, the backswimmerNotonecta undulata, and a sit‐and‐wait predator, the damselflyEnallagma annexum. In a series of predator–prey experiments across a temperature gradient, we measured predator feeding rates on an active prey species, zooplanktonDaphnia pulex, predator growth rates, and mechanisms that influence predator feeding: body speed of predators and prey (here measured as swimming speed), prey encounter rates, capture success, attack rates, and handling time. Overall, warming led to increased feeding rates for both predators through changes to each component of the predator’s functional response. We found that prey swimming speed strongly increased with temperature. The active predator’s swimming speed also increased with temperature, and together, the increase in predator and prey swimming speed resulted in twofold higher prey encounter rates for the active predator at warmer temperatures. By contrast, prey encounter rates of the sit‐and‐wait predator increased fourfold with rising temperatures as a result of increased prey swimming speed. Concurrently, increased prey swimming speed was associated with a decline in the active predator’s capture success at high temperatures, whereas the sit‐and‐wait predator’s capture success slightly increased with temperature. We provide some of the first evidence that foraging traits mediate the indirect effects of warming on predator performance. Understanding how traits influence species’ responses to warming could clarify how climate change will affect entire functional groups of species.