Data from: Escape from predators and genetic variance in birds

Predation is a common cause of death in numerous organisms, and a host of anti-predator defenses have evolved. Such defenses often have a genetic background as shown by significant heritability and micro-evolutionary responses towards weaker defenses in the absence of predators. Flight initiation distance (FID) is the distance at which an individual animal takes flight when approached by a human, and hence it reflects the life history compromise between risk of predation and the benefits of foraging. Here we analyzed FID in 128 species of birds in relation to three measures of genetic variation, band sharing coefficient for minisatellites, observed heterozygosity and inbreeding coefficient for microsatellites in order to test whether FID was positively correlated with genetic variation. We found consistently shorter FID for a given body size in the presence of high band sharing coefficients, low heterozygosity and high inbreeding coefficients in phylogenetic analyses after controlling statistically for potentially confounding variables. These findings imply that anti-predator behavior is related to genetic variance. We predict that many threatened species with low genetic variability will show reduced anti-predator behavior, and that subsequent predator-induced reductions in abundance may contribute to unfavorable population trends for such species.捕食是众多生物常见的致死诱因，由此演化出了丰富多样的反捕食防御策略。这类防御策略往往具有遗传基础，这一点可通过显著的遗传力以及无捕食者环境下防御能力弱化的微进化响应得到佐证。逃逸起始距离（Flight initiation distance, FID）指单个动物在人类接近时启动逃逸行为的距离，因此它反映了捕食风险与觅食收益之间的生活史权衡。本研究针对128种鸟类的FID展开分析，结合三项遗传变异测量指标——小卫星（minisatellites）的条带共享系数、微卫星（microsatellites）的观测杂合度与近交系数，以检验FID是否与遗传变异呈正相关。在对潜在混杂变量进行统计学控制后，系统发育分析结果显示：在给定体型大小的前提下，条带共享系数较高、观测杂合度较低以及近交系数较高的类群，其FID普遍更短。上述发现表明反捕食行为与遗传变异存在关联。我们据此预测，许多遗传多样性较低的受威胁物种，其反捕食行为能力会出现衰减，而后续由捕食者驱动的种群数量缩减，可能会进一步加剧这类物种的种群衰退趋势。