Cooperative sentinel calling?: Foragers gain increased biomass intake
Cooperative sentinel calling?: Foragers gain increased biomass intake
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DOI：
10.1016/j.cub.2008.02.078
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发表时间：
2008-04-22
期刊：
影响因子：
9.2
通讯作者：
Radford, Andrew N.
中科院分区：
文献类型：
--
作者：
Hollen, Linda I.;Bell, Matthew B. V.;Radford, Andrew N.
许多觅食动物面临着捕食和饥饿之间的基本权衡[1，2]。在一系列社会性物种中，这种权衡可能推动了哨兵行为的进化，即个体采取突出的位置来观察捕食者，而群体觅食[3]。虽然有很多关于作为哨兵是自私还是合作行为的争论[3-6]，但很少有人关注为什么哨兵经常发出安静的声音（以下称为“哨兵呼叫”）来宣布他们的存在[7，8]。我们使用观察和实验数据提供的第一个证据表明，组成员获得增加觅食成功的哨兵，这些声音提示作出反应。觅食的画眉鸟（Turdoides bicolor）更分散，使用更多暴露的补丁，不经常抬头，花更少的时间警惕地回应哨兵呼叫。至关重要的是，我们证明了这些行为的改变导致觅食动物的生物量摄入增加，这可能会提高生存率。我们认为，这种好处可能是哨兵呼叫的原因，使其成为真正的合作行为[9]。
Many foraging animals face a fundamental tradeoff between predation and starvation [1, 2]. In a range of social species, this tradeoff has probably driven the evolution of sentinel behavior, where individuals adopt prominent positions to watch for predators while groupmates forage [3]. Although there has been much debate about whether acting as a sentinel is a selfish or cooperative behavior [3-6], far less attention has focused on why sentinels often produce quiet vocalizations (hereafter known as "sentinel calls") to announce their presence [7, 8]. We use observational and experimental data to provide the first evidence that group members gain an increase in foraging success by responding to these vocal cues given by sentinels. Foraging pied babblers (Turdoides bicolor) spread out more, use more exposed patches, look up less often, and spend less time vigilant in response to sentinel calling. Crucially, we demonstrate that these behavioral alterations lead to an increase in biomass intake by foragers, which is likely to enhance survival. We argue that this benefit may be the reason for sentinel calling, making it a truly cooperative behavior [9].