Abstract

Prey species often mitigate predation risk through alteration of spatiotemporal diel activity patterns whereby prey access high-quality resources in risky areas during predator downtimes. However, dominance hierarchies exist in some prey species, and temporal partitioning is a mechanism thought to reduce aggressive intraspecific interactions. How demographic-specific responses to predation risk influence intraspecific temporal partitioning in prey are largely unknown and could be key to understanding the effects of predators on intraspecific interactions in prey. To assess the effects of predation risk on intraspecific interactions in white-tailed deer (Odocoileus virginianus), we monitored deer diel activity during the fawning season in four pairs of predator exclusion and control plots (~40 ha) from 2015 to 2018 using 16 camera traps. We examined the effect of predation risk on diel activity of males, females, and nursery groups by comparing the within-group coefficient of activity overlap (d̂) across predator exclusion and control plots. We then examined within-treatment activity overlap between groups in the predator exclosure and control plots. All groups maintained different diel activity patterns in safe and risky areas. Unconstrained by predation risk, all groups behaved more similarly, and interspecific group overlap was greater in the predator exclusion plots than control plots. Male-nursery group overlap exhibited the strongest treatment effect, increasing 24% in predator exclusion plots (d̂ = 0.91, confidence interval [CI]: 0.87–0.95) relative to control plots (d̂ = 0.67, CI: 0.57–0.76). Our results suggest predators increase heterogeneity in prey behavior and may be important drivers of behavioral processes, such as temporal partitioning, that minimize antagonistic intraspecific interactions of prey.

中文翻译：

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捕食风险会增加白尾鹿diel活动模式的种内异质性

摘要

猎物经常通过时空diel活动模式的改变来减轻捕食风险，从而使捕食者在捕食者宕机时能从危险地区获得高质量的资源。但是，在某些猎物物种中存在优势等级，并且时间划分是一种减少攻击性种内相互作用的机制。人口统计学对捕食风险的反应如何影响猎物内种间时间划分尚不清楚，这可能是了解捕食者对猎物内种间相互作用的影响的关键。评估捕食风险对白尾鹿（Odocoileus virginianus）种内相互作用的影响），我们使用16个摄影机诱集器，在2015年至2018年的四对捕食者排斥和控制地块（〜40公顷）中监测了小鹿季节的鹿角活动。我们通过比较捕食者排斥和控制地块内活动重叠的组内系数（dgroup），研究了捕食风险对雄性，雌性和苗圃组diel活动的影响。然后，我们在捕食者排泄图和对照图中检查了各组之间的治疗内活动重叠。所有组在安全和危险的地区保持不同的diel活动模式。不受捕食风险的约束，所有组的行为都更相似，并且在捕食者排他图中，种间组的重叠要大于对比例。男性护理群体的重叠表现出最强的治疗效果，在捕食者排斥区中增加了24％（d̂ = 0.91，置信区间[CI]：0.87–0.95）相对于对照图（d̂ = 0.67，CI：0.57–0.76）。我们的结果表明，捕食者会增加猎物行为的异质性，并且可能是行为过程（例如时间划分）的重要驱动力，从而最大程度地减少了对立的捕食性对种内相互作用。