Foragers make decisions based on cues, information collected from their environment, processed into strategic behaviours. This information, processed in multiple regions of the brain, ultimately result in the production of stress hormones and visible changes in behaviour of animals - both reflexively to avoid depredation and strategically to avoid an encounter with the predator. In a common-garden experiment we tested how imperfect information from visual cues of a predator impacts foraging and apprehension of a desert rodent, the Egyptian gerbil (Gerbillus pyramidum). The gerbils were exposed to predation by barn owls (Tyto alba), one camouflaged on dark nights using black dye. Gerbils' response to the owls was measured using patch-use measured in giving-up densities (GUDs) and time spent in vigilance activity. Owl lethality was extrapolated from mean times spent in attacks and number of attempted strikes. Dyed owls attack-rate was lower and attack duration greater than those of the white owls. During the full moon, when dyed owls were visible, gerbils responded with extreme vigilance and minimal foraging (high GUDs). During the new moon when the owls were most stealthy, the gerbils showed low vigilance coupled with a similar high GUD. The inconsistency between gerbils' foraging and vigilance behaviours, suggest a likely mismatch between perceived risk and actual measurement of predator lethality gathered by the gerbils' observations in real time.

中文翻译：

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忍者猫头鹰; 沙鼠过度期待一个意想不到的飞行捕食者

觅食者根据线索、从环境中收集的信息、处理成战略行为做出决定。这些信息在大脑的多个区域进行处理，最终导致压力荷尔蒙的产生和动物行为的明显变化——既是反射性地避免掠夺，又是战略性地避免与捕食者相遇。在一个公共花园实验中，我们测试了来自捕食者视觉线索的不完美信息如何影响对沙漠啮齿动物埃及沙鼠（沙鼠金字塔）的觅食和逮捕。沙鼠被谷仓猫头鹰（Tyto alba）捕食，一种在黑夜使用黑色染料伪装。沙鼠对猫头鹰的反应是使用贴片使用测量的，以放弃密度（GUD）和警觉活动花费的时间来衡量。猫头鹰的杀伤力是根据平均攻击时间和未遂攻击次数推断出来的。染色猫头鹰的攻击率低于白猫头鹰，攻击持续时间更长。在满月期间，当可以看到染色的猫头鹰时，沙鼠会以极高的警惕性和极少的觅食（高 GUD）做出反应。在猫头鹰最隐蔽的新月期间，沙鼠表现出低警惕性和类似的高 GUD。沙鼠觅食和警惕行为之间的不一致表明，感知风险与沙鼠实时观察收集的捕食者杀伤力的实际测量之间可能不匹配。当看到染色的猫头鹰时，沙鼠会以极度警惕和极少觅食（高 GUD）作出反应。在猫头鹰最隐蔽的新月期间，沙鼠表现出低警惕性和类似的高 GUD。沙鼠觅食和警惕行为之间的不一致表明，感知风险与沙鼠实时观察收集的捕食者杀伤力的实际测量之间可能不匹配。当看到染色的猫头鹰时，沙鼠会以极度警惕和极少觅食（高 GUD）作出反应。在猫头鹰最隐蔽的新月期间，沙鼠表现出低警惕性和类似的高 GUD。沙鼠觅食和警惕行为之间的不一致表明，感知风险与沙鼠实时观察收集的捕食者杀伤力的实际测量之间可能不匹配。