Abstract:
The ability of predators to adopt hunting tactics that minimise escape reactions from prey is crucial for efficient foraging, and depends on detection capabilities and locomotor performance of both predators and prey. Here, we investigated the efficiency of a small pinniped, the Antarctic fur seal (Arctocephalus gazella) at exploiting their small prey by describing for the first time their fine-scale predator-prey interactions. We compared these with those from another diving predator, the southern elephant seal (Mirounga leonina) that forage on the same prey type. We used data recorded by a newly developed sonar tag that combines active acoustics with ultrahigh-resolution movement sensors to study simultaneously the fine-scale behaviour of both Antarctic fur seals and prey during predator-prey interactions in more than 1200 prey capture events for eight female Antarctic fur seals. Our results showed that Antarctic fur seals and their prey detect each other at the same time, i.e. 1-2 s before the strike, forcing Antarctic fur seals to display reactive fast-moving chases to capture their prey. In contrast, southern elephant seals detect their prey up to 10 s before the strike, allowing them to approach their prey stealthily without triggering an escape reaction. The active hunting tactics used by Antarctic fur seals is probably very energy consuming compared with the stalking tactics used by southern elephant seals but might be compensated for by the consumption of faster-moving larger prey. We suggest that differences in manoeuvrability, locomotor performance and detection capacities and in pace of life between Antarctic fur seals and southern elephant seals might explain these differences in hunting styles.
摘要:
捕食者采取狩猎策略以最大程度地减少猎物的逃避反应的能力对于有效觅食至关重要,并且取决于捕食者和猎物的检测能力和运动性能。在这里,我们研究了一个小插针的效率,南极海豹(Arctocalusgazella,此后的AFS)通过首次描述它们的精细捕食者-猎物相互作用来利用它们的小猎物。我们把它们和另一个潜水捕食者的相比,在相同猎物上觅食的南方象海豹(Miroungaleonina)。我们使用了新开发的声纳标签记录的数据,该标签将主动声学与超高分辨率运动传感器相结合,同时研究了8名女性AFS在1200多个猎物捕获事件中的捕食者-猎物相互作用期间AFS和猎物的精细尺度行为。我们的结果表明,AFS和它们的猎物同时检测到对方,即罢工前1-2秒,迫使AFS显示反应性快速移动的追逐以捕获猎物。相比之下,SES在罢工前10秒检测到它们的猎物,允许他们偷偷地接近他们的猎物,而不会引发逃避反应。与SES使用的跟踪策略相比,AFS使用的主动狩猎策略可能非常消耗能量,但可能会通过消耗移动速度更快的较大猎物来补偿。我们建议机动性的差异,AFS和象海豹之间的运动性能,检测能力和生活节奏可能解释了它们在狩猎方式上的差异。