Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Ecology and Evolutionary Biology, Santa Cruz, CA 95060, USA
Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Ecology and Evolutionary Biology, Santa Cruz, CA 95060, USA.
J Exp Biol. 2019 Mar 4;222(Pt 5):jeb194985. doi: 10.1242/jeb.194985.
Animals use diverse feeding strategies to capture and consume prey, with many species switching between strategies to accommodate different prey. Many marine animals exhibit behavioral flexibility when feeding to deal with spatial and temporal heterogeneity in prey resources. However, little is known about flexibility in the feeding behavior of many large marine predators. Here, we documented the feeding behavior and kinematics of the endangered Hawaiian monk seal (, =7) through controlled feeding trials. Seals were fed multiple prey types (e.g. night smelt, capelin, squid and herring) that varied in size and shape to examine behavioral flexibility in feeding. Hawaiian monk seals primarily used suction feeding (91% of all feeding trials) across all prey types, but biting, specifically pierce feeding, was also observed (9% of all feeding trials). Suction feeding was characterized by shorter temporal events, a smaller maximum gape and gape angle, and a fewer number of jaw motions than pierce feeding; suction feeding kinematic performance was also more variable compared with pierce feeding. Seals showed behavioral flexibility in their use of the two strategies. Suction feeding was used most frequently when targeting small to medium sized prey and biting was used with increasing frequency on larger prey. The feeding kinematics differed between feeding strategies and prey types, showing that Hawaiian monk seals adjusted their behaviors to particular feeding contexts. Hawaiian monk seals are opportunistic marine predators and their ability to adapt their feeding strategy and behavior to specific foraging scenarios allows them to target diverse prey resources.
动物使用多种摄食策略来捕捉和进食猎物，许多物种会根据不同的猎物来切换策略。许多海洋动物在摄食时表现出行为灵活性，以应对猎物资源在空间和时间上的异质性。然而，对于许多大型海洋捕食者的摄食行为灵活性，我们知之甚少。在这里，我们通过控制摄食试验记录了濒危夏威夷僧海豹（=7）的摄食行为和运动学。海豹被喂食多种不同大小和形状的猎物类型（如夜鳚、毛鳞鱼、鱿鱼和鲱鱼），以检查摄食行为的灵活性。夏威夷僧海豹主要使用抽吸摄食（所有摄食试验的 91%），但也观察到了咬食，特别是刺穿摄食（所有摄食试验的 9%）。抽吸摄食的特点是时间事件更短、最大张口和张口角度更小、颌骨运动次数更少；与刺穿摄食相比，抽吸摄食的运动学性能也更具可变性。海豹在使用两种策略方面表现出行为灵活性。当目标是中小体型的猎物时，抽吸摄食使用最频繁，而随着体型较大的猎物的增加，刺穿摄食的使用频率也在增加。摄食运动学在摄食策略和猎物类型之间存在差异，表明夏威夷僧海豹根据特定的摄食环境调整了它们的行为。夏威夷僧海豹是机会主义的海洋捕食者，它们能够调整摄食策略和行为以适应特定的觅食场景，从而能够针对多样化的猎物资源。
