Crawford Daniel A, Cherry Michael J, Kelly Brian D, Garrison Elina P, Shindle David B, Conner L Mike, Chandler Richard B, Miller Karl V
Warnell School of Forestry and Natural Resources University of Georgia Athens Georgia.
College of Natural Resources and Environment Virginia Polytechnic Institute and State University Blacksburg Virginia.
Ecol Evol. 2019 Feb 26;9(6):3264-3275. doi: 10.1002/ece3.4947. eCollection 2019 Mar.
Fear of predators can behaviorally mediate prey population dynamics, particularly when predation risk influences reproductive investment. However, the costs of reproductive investment may mitigate predation risk aversion relative to periods when the link between reproductive output and prey behavior is weaker.We posit that intensity of reproductive investment in ungulates may predict their response to predation risk such that the sexes increase risk exposure during biological seasons that are pivotal to reproductive success, such as the fawn-rearing and breeding seasons for females and males, respectively.We examined the activity patterns of sympatric white-tailed deer (), a sexually segregated polygynous ungulate, and Florida panthers () in the context of the "risky times - risky places hypothesis" and the reproductive strategy hypothesis. We compared detection rates and diel activity overlap of both species using motion-triggered camera traps positioned on ( = 120) and off ( = 60) anthropogenic trails across five reproductive seasons.Florida panthers were nocturnal and primarily observed on-trail providing an experimental framework with risky times and risky places. Contrary to studies in other taxa inversely correlating prey reproductive investment to predation risk, the sexes of deer were more risk prone during sex-specific seasons associated with intense reproductive investment.Our results suggest spatiotemporally variable predation risk influences sex-specific behavioral decision-making in deer such that reproductive success is maximized.
对捕食者的恐惧会在行为上调节猎物的种群动态，尤其是当捕食风险影响生殖投资时。然而，相对于生殖产出与猎物行为之间的联系较弱的时期，生殖投资的成本可能会减轻对捕食风险的厌恶。我们假设，有蹄类动物生殖投资的强度可能预示着它们对捕食风险的反应，即两性在对生殖成功至关重要的生物季节增加风险暴露，例如雌性的育幼季节和雄性的繁殖季节。我们在“危险时期 - 危险地点假说”和生殖策略假说的背景下，研究了同域分布的白尾鹿（一种性别隔离的多配偶有蹄类动物）和佛罗里达美洲狮的活动模式。我们使用运动触发式相机陷阱，在五个生殖季节中，对位于人为小径上（n = 120）和小径外（n = 60）的两种物种的检测率和昼夜活动重叠进行了比较。佛罗里达美洲狮是夜行性动物，主要在小径上被观察到，这提供了一个具有危险时期和危险地点的实验框架。与其他将猎物生殖投资与捕食风险呈负相关的类群研究相反，鹿的两性在与高强度生殖投资相关的特定性别季节更倾向于冒险。我们的结果表明，时空变化的捕食风险会影响鹿的性别特异性行为决策，从而使生殖成功率最大化。
