Effects of age and reproductive status on individual foraging site fidelity in a long-lived marine predator

Individual foraging specializations, where individuals use a small component of the population niche width, are widespread in nature with important ecological and evolutionary implications. In long-lived animals, foraging ability develops with age, but we know little about the ontogeny of individuality in foraging. Here we use precision global positioning system (GPS) loggers to examine how individual foraging site fidelity (IFSF), a common component of foraging specialization, varies between breeders, failed breeders and immatures in a long-lived marine predator—the northern gannet Morus bassanus. Breeders (aged 5+) showed strong IFSF: they had similar routes and were faithful to distal points during successive trips. However, centrally placed immatures (aged 2–3) were far more exploratory and lacked route or foraging site fidelity. Failed breeders were intermediate: some with strong fidelity, others being more exploratory. Individual foraging specializations were previously thought to...个体觅食特化现象——即个体仅利用种群生态位宽度中的一小部分资源——在自然界中广泛存在，且具有重要的生态学与进化学意义。对于长寿动物而言，觅食能力会随年龄增长而发育，但目前我们对觅食行为中个体特征的个体发育过程仍知之甚少。本研究借助高精度全球定位系统（GPS）记录仪，探究了觅食特化的常见表现形式——个体觅食位点忠实性（individual foraging site fidelity, IFSF）——在长寿海洋捕食者北鲣鸟（Morus bassanus）的繁殖个体、繁殖失败个体与未成熟个体之间的差异。5岁及以上的繁殖个体表现出极强的个体觅食位点忠实性：它们在多次觅食行程中会遵循相似的飞行路线，且忠实于此前选定的远端觅食位点。与之相反，2至3岁的未成熟个体（活动范围集中于中心区域）则表现出更强的探索性，既无固定飞行路线，也不存在觅食位点忠实性。繁殖失败的个体则处于中间状态：部分个体表现出较强的觅食位点忠实性，另一部分则更倾向于探索行为。此前学界普遍认为，个体觅食特化现象……