Data from: Maternal programming of offspring antipredator behavior in a seabird

Predation risk is an important environmental factor for animal populations, expected to trigger maternal effects to prepare offspring for living in an environment with predators. Yet, evidence of adaptive anticipatory maternal effects in wild animals is still weak. Here, we explored this question in a wild colony of yellow-legged gulls, Larus michahellis. To this aim, prior to laying we exposed mothers to either mink decoys or non-predator rabbit decoys and explored the antipredator behavior of 118 chicks at the age of two days. We found that chicks from second-laid eggs by predator-exposed mothers crouched faster after hearing a playback with adult alarm calls than chicks from second-laid eggs by control mothers. Besides, chicks from third-laid eggs by predator-exposed mothers were lighter than control chicks, but this was not due to differences in egg volume. Our results suggest that predator-exposed mothers modified offspring phenotype via eggs to cope with predators, although only in chicks from second-laid eggs. Maternal transference of corticosterone could underlie chick behavioral plasticity. Results support the role of maternal effects as a form of phenotype programming to forewarn offspring about environmental hazards.

捕食风险是影响动物种群的关键环境因子，可触发母体效应（maternal effects），使子代做好适应存在捕食者的环境的准备。然而，目前关于野生动物中适应性预期型母体效应（adaptive anticipatory maternal effects）的研究证据仍较为匮乏。本研究以野生黄腿鸥（Larus michahellis）种群为研究对象，针对这一科学问题展开探究。为实现研究目标，我们在产卵前将待产母鸥分别暴露于水貂模型与非捕食者家兔模型的环境中，并对118只两日龄雏鸥的反捕食行为进行观测。研究结果显示：暴露于捕食者环境的母鸥所产第二枚卵孵化的雏鸥，在听到成鸟告警叫声回放时，其蹲伏反应速度显著快于对照组母鸥所产第二枚卵孵化的雏鸥。此外，暴露于捕食者环境的母鸥所产第三枚卵孵化的雏鸥，其体重低于对照组雏鸥，但该差异并非由卵体积差异所导致。本研究结果表明：尽管该效应仅在第二枚卵孵化的雏鸥中被观测到，但暴露于捕食者环境的母鸥可通过产卵途径改变子代的表型（phenotype），以帮助子代应对捕食者威胁。母鸥体内皮质酮（corticosterone）的子代传递，或可作为雏鸥行为可塑性（behavioral plasticity）的潜在调控机制。本研究结果证实，母体效应可作为一种表型编程方式，提前向子代预警环境中的潜在危害。