School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK.
Biol Lett. 2020 May;16(5):20200098. doi: 10.1098/rsbl.2020.0098. Epub 2020 May 13.
Predators must often employ flexible strategies to capture prey. Particular attention has been given to the strategies of visual predators that actively pursue their prey, but sit-and-wait predators have been largely overlooked, their strategies often characterized as stereotyped. Praying mantids are primarily sit-and-wait predators that often employ crypsis to catch their prey using a raptorial strike produced by their highly modified forelimbs. Here, we show that the raptorial strike of the Madagascan marbled mantis () varies in duration from 60 to 290 ms due to the tibial extension alone; slower strikes involve slower tibial extensions that may also be interrupted by a pause. The success of a strike is independent of its duration or the presence of these pauses. However, prey speed affects the duration of tibial extension and the probability of a pause occurring, both increasing at slower prey speeds. Adjusting the duration of the tibial extension according to prey speed allows mantids to time the final downward sweep of the tibia to their prey's approach. The use of visual inputs to adjust the motor pattern controlling forelimb movements shows that not all aspects of the strike are stereotyped and that sit-and-wait predators can produce behavioural flexibility.
捕食者通常必须采用灵活的策略来捕获猎物。人们特别关注主动追捕猎物的视觉捕食者的策略，但对坐以待兔的捕食者却关注甚少，它们的策略通常被认为是刻板的。螳螂主要是坐以待兔的捕食者，它们经常使用伪装来捕捉猎物，方法是用高度特化的前肢进行猛扑。在这里，我们表明马达加斯加大理石螳螂的猛扑持续时间可因胫骨伸展而在 60 到 290 毫秒之间变化；较慢的猛扑涉及较慢的胫骨伸展，也可能被暂停打断。猛扑的成功与否与其持续时间或是否存在这些暂停无关。然而，猎物的速度会影响胫骨伸展的持续时间和暂停发生的概率，在较慢的猎物速度下，这两个因素都会增加。根据猎物速度调整胫骨伸展的持续时间可以使螳螂能够根据猎物的接近情况调整胫骨向下扫动的时间。使用视觉输入来调整控制前肢运动的运动模式表明，并非猛扑的所有方面都是刻板的，而且坐以待兔的捕食者可以产生行为灵活性。
