Keeping momentum with a mouthful of water: behavior and kinematics of humpback whale lunge feeding
Keeping momentum with a mouthful of water: behavior and kinematics of humpback whale lunge feeding
复制标题
用一口水保持动力：座头鲸弓步进食的行为和运动学
DOI：
10.1242/jeb.071092
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发表时间：
2012
影响因子：
2.8
通讯作者：
P. Madsen
中科院分区：
文献类型：
--
作者：
M. Simon;Mark P Johnson;P. Madsen
长须鲸通过在一个大的可膨胀的颊囊中吞噬成吨的载有猎物的水来捕食。根据先前的解释，进食的罗夸犬在每次弓步结束时几乎停止，主要是由张开的嘴产生的阻力。从静止状态加速身体是能量消耗很大的，据说是决定肺喂养的呼吸机氧气消耗的关键因素，这解释了它们的尺寸比预期的潜水时间短。在这里，我们使用多传感器档案标签（DTAGs）采样率高，在一个细尺度的运动学研究的弓步喂养检查弓步内的事件序列，以及如何在捕获猎物的过程中消耗和保存能量。对五头座头鲸的479次弓步的分析表明，鲸鱼在捕获猎物时会加速，张开嘴巴与强烈的侥幸中风同步。在吞噬过程中，高的前进速度（平均深度速率：2.0±0.32 m s-1）既可以捕获活跃的猎物，也可以扩大颊囊的腹侧边缘，从而使吞噬的水量最大化。减速开始后，嘴张开时，袋接近充分扩大和势头开始转移到吞没的水。以弓步为食的座头鲸会在整个弓步过程中把握时机，给被吞没的水体施加动量，从而避免接近或完全停止，而是在弓步结束后继续以约1-1.5 m s−1的速度滑行。随后的过滤和猎物处理似乎平均需要46秒，并与下一个弓步的重新定位平行进行。
SUMMARY Rorqual baleen whales lunge feed by engulfment of tons of prey-laden water in a large and expandable buccal pouch. According to prior interpretations, feeding rorquals are brought to a near-halt at the end of each lunge by drag forces primarily generated by the open mouth. Accelerating the body from a standstill is energetically costly and is purported to be the key factor determining oxygen consumption in lunge-feeding rorquals, explaining the shorter dive times than expected given their sizes. Here, we use multi-sensor archival tags (DTAGs) sampling at high rates in a fine-scale kinematic study of lunge feeding to examine the sequence of events within lunges and how energy may be expended and conserved in the process of prey capture. Analysis of 479 lunges from five humpback whales reveals that the whales accelerate as they acquire prey, opening their gape in synchrony with strong fluke strokes. The high forward speed (mean depth rate: 2.0±0.32 m s−1) during engulfment serves both to corral active prey and to expand the ventral margin of the buccal pouch and so maximize the engulfed water volume. Deceleration begins after mouth opening when the pouch nears full expansion and momentum starts to be transferred to the engulfed water. Lunge-feeding humpback whales time fluke strokes throughout the lunge to impart momentum to the engulfed water mass and so avoid a near or complete stop, but instead continue to glide at ~1–1.5 m s−1 after the lunge has ended. Subsequent filtration and prey handling appear to take an average of 46 s and are performed in parallel with re-positioning for the next lunge.