Potash Alex D, Conner L Mike, Clinchy Michael, Zanette Liana Y, McCleery Robert A
Department of Wildlife Ecology, University of Florida Institute of Food and Agricultural Science, 110 Newins-Ziegler Hall, P.O. Box 110430, Gainesville, FL, 32611, USA.
The Jones Center at Ichauway, 3988 Jones Center Drive, Newton, GA, 39870, USA.
Oecologia. 2023 Mar;201(3):661-671. doi: 10.1007/s00442-023-05350-9. Epub 2023 Mar 10.
The decline of terrestrial predator populations across the globe is altering top-down pressures that drive predator-prey interactions. However, a knowledge gap remains in understanding how removing terrestrial predators affects prey behavior. Using a bifactorial playback experiment, we exposed fox squirrels to predator (red-tailed hawks, coyotes, dogs) and non-predator control (Carolina wren) calls inside terrestrial predator exclosures, accessible to avian predators, and in control areas subject to ambient predation risk. Fox squirrels increased their use of terrestrial predator exclosures, a pattern that corresponded with 3 years of camera trapping. Our findings suggest fox squirrels recognized that exclosures had predictably lower predation risk. However, exclosures had no effect on their immediate behavioral response towards any call, and fox squirrels responded most severely to hawk predator calls. This study shows that anthropogenically driven predator loss creates predictably safer areas (refugia) that prey respond to proactively with increased use. However, the persistence of a lethal avian predator is sufficient to retain a reactive antipredator response towards an immediate predation threat. Some prey may benefit from shifting predator-prey interactions by gaining refugia without sacrificing a sufficient response towards potential predators.
全球陆地捕食者种群数量的减少正在改变驱动捕食者与猎物相互作用的自上而下的压力。然而，在理解去除陆地捕食者如何影响猎物行为方面仍存在知识空白。我们通过双因素回放实验，在陆地捕食者围栏内、鸟类捕食者可进入的区域以及存在环境捕食风险的对照区域，让狐松鼠接触捕食者（红尾鹰、郊狼、狗）和非捕食者对照（卡罗来纳鹪鹩）的叫声。狐松鼠增加了对陆地捕食者围栏的使用，这一模式与三年的相机捕捉结果相符。我们的研究结果表明，狐松鼠认识到围栏内的捕食风险可预测地更低。然而，围栏对它们对任何叫声的即时行为反应没有影响，并且狐松鼠对鹰捕食者的叫声反应最为强烈。这项研究表明，人为导致的捕食者损失创造了可预测的更安全区域（避难所），猎物会通过增加对其的使用来积极响应。然而，致命鸟类捕食者的存在足以使猎物对即时捕食威胁保持反应性的反捕食反应。一些猎物可能通过获得避难所而不牺牲对潜在捕食者的充分反应，从改变的捕食者 - 猎物相互作用中受益。
