Despite a wealth of studies documenting prey responses to perceived predation risk, researchers have only recently begun to consider how prey integrate information from multiple cues in their assessment of risk. We conduct a systematic review and meta-analysis of studies that experimentally manipulated perceived predation risk in birds and evaluate support for three alternative models of cue integration: redundancy/equivalence, enhancement, and antagonism. One key insight from our analysis is that the current theory, generally applied to study cue integration in animals, is incomplete. These theories specify the effects of increasing information level on mean, but not variance, in responses. In contrast, we show that providing multiple complementary cues of predation risk simultaneously does not affect mean response. Instead, as information richness increases, populations appear to assess risk more accurately, resulting in lower among-population variance in response to manipulations of perceived predation risk. We show that this may arise via a statistical process called maximum-likelihood estimation (MLE) integration. Our meta-analysis illustrates how explicit consideration of variance in responses can yield important biological insights.

尽管有大量研究记录了猎物对感知到的捕食风险的反应，但研究人员最近才开始考虑猎物如何在风险评估中整合来自多种线索的信息。我们对通过实验操纵鸟类感知捕食风险的研究进行了系统回顾和荟萃分析，并评估了对线索整合的三种替代模型的支持：冗余/等价、增强和拮抗。我们分析的一个关键见解是，目前通常用于研究动物线索整合的理论是不完整的。这些理论具体说明了增加信息水平对响应平均值的影响，但没有对方差的影响。相比之下，我们表明同时提供捕食风险的多个补充线索不会影响平均反应。相反，随着信息丰富度的增加，种群似乎能够更准确地评估风险，从而导致对感知捕食风险的操纵产生较小的种群间差异。我们证明这可能是通过称为最大似然估计（MLE）积分的统计过程产生的。我们的荟萃分析说明了明确考虑反应差异如何能够产生重要的生物学见解。