School of Biological & Marine Sciences, Plymouth University, Plymouth, PL4 8AA, UK.
Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 8LB, UK.
Sci Rep. 2017 Nov 14;7(1):15505. doi: 10.1038/s41598-017-15859-8.
Young animals must learn to forage effectively to survive the transition from parental provisioning to independent feeding. Rapid development of successful foraging strategies is particularly important for capital breeders that do not receive parental guidance after weaning. The intrinsic and extrinsic drivers of variation in ontogeny of foraging are poorly understood for many species. Grey seals (Halichoerus grypus) are typical capital breeders; pups are abandoned on the natal site after a brief suckling phase, and must develop foraging skills without external input. We collected location and dive data from recently-weaned grey seal pups from two regions of the United Kingdom (the North Sea and the Celtic and Irish Seas) using animal-borne telemetry devices during their first months of independence at sea. Dive duration, depth, bottom time, and benthic diving increased over the first 40 days. The shape and magnitude of changes differed between regions. Females consistently had longer bottom times, and in the Celtic and Irish Seas they used shallower water than males. Regional sex differences suggest that extrinsic factors, such as water depth, contribute to behavioural sexual segregation. We recommend that conservation strategies consider movements of young naïve animals in addition to those of adults to account for developmental behavioural changes.
幼年动物必须学会有效地觅食，才能从父母提供的食物过渡到独立进食。对于那些在断奶后没有父母指导的资本繁殖者来说，成功的觅食策略的快速发展尤为重要。许多物种的觅食发生的内在和外在驱动因素的变化还了解甚少。灰海豹（Halichoerus grypus）是典型的资本繁殖者；幼崽在短暂的哺乳期后被遗弃在出生地，必须在没有外部输入的情况下发展觅食技能。我们使用动物携带的遥测设备，在英国的两个地区（北海和凯尔特海和爱尔兰海）收集了最近断奶的灰海豹幼崽的位置和潜水数据，这些幼崽在海上独立的头几个月里。潜水持续时间、深度、底部时间和底栖潜水都在头 40 天增加。变化的形状和幅度在不同地区有所不同。雌性的底部时间始终较长，而且在凯尔特海和爱尔兰海中，它们的潜水深度比雄性浅。区域性别差异表明，外在因素，如水深，会导致行为上的性别隔离。我们建议保护策略考虑年轻的新生动物的运动，除了那些成年动物，以解释发育行为的变化。
