Data from: Evidence for nonconsumptive effects from a large predator in an ungulate prey?

Pedators can indirectly affect prey survival and reproduction by evoking costly anti-predator responses. Such non-consumptive effects may be as strong or stronger than consumptive predator effects. However, evidence for this in large terrestrial vertebrate systems is equivocal and few studies quantify the actual fitness costs of non-consumptive effects. Here we investigated whether non-consumptive effects elicited by Eurasian lynx (Lynx lynx), a large terrestrial predator, reduced survival in an ungulate prey, the European roe deer (Capreolus capreolus). To reveal the behavioral processes underlying non-consumptive effects, we distinguished between proactive risk avoidance of areas with high lynx encounter probability, and reactive risk avoidance in response to actual lynx encounters and analyzed these responses using step selection functions. We also quantified the consequences of these behaviors for deer survival. Deer reacted differently at day and at night, but avoided high-risk areas proactively during the day and at night in the summer. During a predator encounter, deer increased avoidance of high-risk areas at night but not during the day. Thus, roe deer exhibited a behavioral response race that involved temporally and spatially varying tradeoffs with environmental constraints. We found evidence that non-consumptive effects of lynx predation risk reduced deer survival and that survival was more sensitive to variation in non-consumptive effects of lynx than to variation in human proximity. Our findings highlight that non-consumptive effects may depend on the spatiotemporal distribution of risks and the environmental context, and we discuss how human factors contribute to predator-prey dynamics in human dominated landscapes.捕食者可通过触发代价高昂的反捕食行为响应，间接影响猎物的存活与繁殖成功率。这类非消耗性效应（non-consumptive effects）的强度可与捕食者的消耗性效应相当，甚至更强。但目前在大型陆生脊椎动物系统中，相关研究证据仍存争议，且鲜有研究量化非消耗性效应的实际适合度成本。本研究旨在探究大型陆生捕食者欧亚猞猁（Lynx lynx）引发的非消耗性效应，是否会降低其有蹄类猎物——欧洲狍（Capreolus capreolus）的存活率。为揭示非消耗性效应背后的行为机制，我们将风险规避行为划分为两类：主动规避高猞猁遭遇概率的区域，以及针对实际遭遇猞猁的反应性风险规避，并通过步选择函数（step selection functions）对上述行为响应开展分析。此外，我们还量化了这些行为对狍存活的影响。研究发现，狍的行为反应存在昼夜差异：在夏季，无论白天还是夜间，狍均会主动规避高风险区域；而当遭遇捕食者时，狍仅在夜间会进一步强化对高风险区域的规避行为，白天则无此响应。由此可见，欧洲狍展现出一种随时间与空间动态调整的行为响应权衡策略，需平衡各类环境约束带来的利弊取舍。本研究证实，猞猁捕食风险带来的非消耗性效应会降低狍的存活率，且狍的存活率对猞猁非消耗性效应变化的敏感性，高于其对人类活动干扰程度变化的敏感性。我们的研究结果表明，非消耗性效应的强弱可能取决于风险的时空分布与环境背景，并讨论了人类活动因素如何在人类主导的景观中调控捕食者-猎物的动态关系。