Breeding synchrony and predator specialization: a test of the predator swamping hypothesis in seabirds

Reproductive synchrony is a widespread phenomenon that is predicted to be adaptive for prey with specialist predators but not for those with generalist ones. I tested this prediction in three polar seabird species characterized by different levels of predator specialization. In the Antarctic petrel, for which the only predator was highly specialized, hatching dates were highly synchronous and chicks that hatched close to the mean hatching date had a higher survival. In black-legged kittiwakes and Brünnich’s guillemots, whose predators were generalists, breeding was less synchronous and there was no fitness advantage in hatching close to the mean. This study emphasizes the potential importance of the relative timing of reproduction for individual fitness and supports the hypothesis that the adaptive value of breeding synchrony depends on the predator functional response.

繁殖同步性（reproductive synchrony）是一种广泛存在的生态学现象，现有理论预测其对拥有特化捕食者的猎物具有适应性优势，而对拥有泛化捕食者的猎物则无此类优势。本研究针对三种捕食特化程度各异的极地海鸟物种，对该预测展开实证检验。在南极海燕（Antarctic petrel）中，其唯一捕食者为高度特化的物种，雏鸟的孵化日期呈现出高度同步性，且孵化时间接近平均孵化日期的雏鸟存活率更高。而在捕食者为泛化物种的黑脚三趾鸥（black-legged kittiwakes）和布氏海鸠（Brünnich's guillemots，原文本存在编码乱码已修正）中，繁殖同步性较弱，且孵化时间贴近平均孵化日期并不会带来适合度优势。本研究强调了繁殖相对时间对个体适合度的潜在重要性，并支持“繁殖同步性的适应性价值取决于捕食者功能响应（predator functional response）”这一假说。