South for the winter? Within-dive foraging effort reveals the trade-offs between divergent foraging strategies in a free-ranging predator
South for the winter? Within-dive foraging effort reveals the trade-offs between divergent foraging strategies in a free-ranging predator
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DOI：
10.1111/1365-2435.12636
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发表时间：
2016-10-01
影响因子：
5.2
通讯作者：
Lea, Mary-Anne
中科院分区：
文献类型：
--
作者：
Arthur, Benjamin;Hindell, Mark;Lea, Mary-Anne
动物适应性的核心是其觅食策略，理解觅食动物的选择是动物生态学的一个基本目标。对潜水动物来说，量化潜水中的觅食努力提供了一个觅食的衡量标准，可以与位置信息相结合，以揭示动物如何利用它们的环境以及与对比觅食策略相关的权衡。（北极瞪羚）在繁殖后的冬季迁徙中，使用一种新的方法来量化潜水内的觅食努力，以确定不同的觅食策略，并确定与觅食决策相关的成本和收益。在潜水行为和觅食努力的女性南极海狗的显着差异可以归因于两个主要的，对比觅食策略。栖息地是潜水和觅食行为的一个主要决定因素，在南大洋的一个突出的海洋学特征-极锋两侧出现了明显的差异。更长的夜间持续时间和改善获得垂直迁移的猎物导致增加觅食机会和减少觅食努力南部的极锋。这一地区的潜水时间短而浅。相反，海豹留在更接近繁殖殖民地北部的极地前线有深，长潜水和提高觅食的努力。海狗独特的觅食策略与栖息地可用性、旅行成本、猎物可及性和猎物质量有关，这可能是它们觅食决策的驱动力。这项研究强调了对比觅食策略，目前共存于一个广泛的捕食者的人口之间的权衡，并提出了有关战略的可行性与未来的人口规模或环境条件的变化的问题。最后，了解与觅食策略相关的权衡对于评估动物在各种环境中的觅食决策非常重要。
Central to an animal's fitness is its foraging strategy and understanding the choices made by foraging animals is a fundamental aim in animal ecology. For diving animals, quantifying foraging effort within dives provides a measure of foraging that can be integrated with location information to reveal how animals use their environment as well as the trade-offs associated with contrasting foraging strategies.We investigated the diving behaviour of 12 free-ranging Antarctic fur seals (Arctocephalus gazella) during their post-breeding winter migrations, quantifying within-dive foraging effort using a novel approach to identify divergent foraging strategies and determine the costs and benefits associated with foraging decisions. Significant differences identified in both diving behaviour and foraging effort of female Antarctic fur seals could be attributed to two main, contrasting foraging strategies. Habitat was a major determinant of diving and foraging behaviour, with clear differences occurring either side of the Polar Front, a prominent oceanographic feature in the Southern Ocean. Longer night duration and improved access to vertically migrating prey lead to increased foraging opportunities and a reduced foraging effort south of the Polar Front. Dives in this region were short and shallow. Conversely, seals remaining closer to the breeding colony north of the Polar Front had deep, long dives and an elevated foraging effort. The distinct foraging strategies of fur seals have associated trade-offs related to habitat availability, travel costs, prey accessibility and prey quality, which are likely driving their foraging decisions. This study highlights the trade-offs between contrasting foraging strategies that currently coexist within a population of a wide-ranging predator and raises questions about the viability of strategies with future change to population size or environmental conditions. Finally, understanding the trade-offs associated with foraging strategies is important for assessing the foraging decisions of animals across a variety of environments.