Department of Biology, University of Wisconsin Eau Claire, Eau Claire, WI, USA.
Department of Biology, Mills College, 5000 MacArthur Blvd, Oakland, CA 94631, USA.
Proc Biol Sci. 2023 Oct 25;290(2009):20231812. doi: 10.1098/rspb.2023.1812.
Sensory integration theory predicts natural selection should favour adaptive responses of animals to multiple forms of information, yet empirical tests of this prediction are rare, particularly in free-living mammals. Studying indirect predator cues offers a salient opportunity to inquire about multimodal risk assessment and its potentially interactive effects on prey responses. Here we exposed California ground squirrels from two study sites (that differ in human and domestic dog activity) to acoustic and/or olfactory predator cues to reveal divergent patterns of signal dominance. Olfactory information most strongly predicted space use within the testing arena. That is, individuals, especially those at the human-impacted site, avoided coyote urine, a danger cue that may communicate the proximity of a coyote. By contrast, subjects allocated less time to risk-sensitive behaviours when exposed to acoustic cues. Specifically, although individuals were consistent in their behavioural responses across trials, 'quiet coyotes' (urine without calls) significantly increased the behavioural reactivity of prey, likely because coyotes rarely vocalize when hunting. More broadly, our findings highlight the need to consider the evolution of integrated fear responses and contribute to an emerging understanding of how animals integrate multiple forms of information to trade off between danger and safety cues in a changing world.
感觉统合理论预测，自然选择应该有利于动物对多种形式的信息做出适应性反应，但对这一预测的实证检验却很少见，特别是在自由生活的哺乳动物中。研究间接的捕食者线索提供了一个很好的机会，可以探究多模态风险评估及其对猎物反应的潜在交互作用。在这里，我们让来自两个研究地点（人类和家犬活动程度不同）的加利福尼亚地松鼠接触到声音和/或嗅觉的捕食者线索，以揭示信号优势的发散模式。嗅觉信息最强烈地预测了测试场地内的空间利用。也就是说，个体，尤其是那些在人类活动影响大的地方的个体，会避开郊狼尿液，这种危险的信号可能表明郊狼就在附近。相比之下，当暴露在声音线索下时，个体分配给风险敏感行为的时间较少。具体来说，尽管个体在不同的试验中表现出一致的行为反应，但“安静的郊狼”（没有叫声的尿液）显著增加了猎物的行为反应性，这可能是因为郊狼在狩猎时很少发声。更广泛地说，我们的研究结果强调了需要考虑综合恐惧反应的进化，并有助于更好地理解动物如何整合多种形式的信息，在不断变化的世界中权衡危险和安全信号。
