Am Nat. 2020 Apr;195(4):636-648. doi: 10.1086/707544. Epub 2020 Feb 13.
The ability of prey to assess predation risk is fundamental to their success. It is routinely assumed that predator cues do not vary in reliability across levels of predation risk. We propose that cues can differ in how precisely they indicate different levels of predation risk. What we call danger cues precisely indicate high risk levels, while safety cues precisely indicate low risk levels. Using optimality modeling, we find that prey fitness is increased when prey pay more attention to safety cues than to danger cues. This fitness advantage is greater when prey need to protect assets, predators are more dangerous, or predation risk increases at an accelerating rate with prey foraging efforts. Each of these conditions lead to prey foraging less when estimated predation risk is higher. Danger cues have less value than safety cues because they give precise information about risk when it is high, but prey behavior varies little when risk is high. Safety cues give precise information about levels of risk where prey behavior varies. These results highlight how our fascination with predators may have biased the way that we study predator-prey interactions and focused too exclusively on cues that clearly indicate the presence of predator rather than cues that clearly indicate their absence.
猎物评估捕食风险的能力对其成功至关重要。通常认为，捕食者线索在不同捕食风险水平上的可靠性不会变化。我们提出，线索可以在指示不同水平的捕食风险的准确性上有所不同。我们称之为危险线索的线索准确地指示高风险水平，而安全线索则准确地指示低风险水平。通过最优化建模，我们发现当猎物更关注安全线索而不是危险线索时，其适应性会增加。当猎物需要保护资产、捕食者更危险或捕食风险随着猎物觅食努力而加速增加时，这种适应性优势更大。当估计的捕食风险较高时，这些条件中的每一个都会导致猎物觅食减少。危险线索的价值不如安全线索高，因为它们在风险高时提供了有关风险的准确信息，但当风险高时，猎物的行为变化很小。安全线索提供了有关猎物行为变化的风险水平的准确信息。这些结果突出表明，我们对捕食者的着迷可能会影响我们研究捕食者-猎物相互作用的方式，并过于专注于那些明显表明捕食者存在的线索，而不是那些明显表明捕食者不存在的线索。
