Three-dimensional movements and swimming activity of a northern elephant seal
Three-dimensional movements and swimming activity of a northern elephant seal
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DOI：
10.1016/s1095-6433(01)00345-2
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发表时间：
2001-07-01
影响因子：
2.3
通讯作者：
Le Boeuf, BJ
中科院分区：
文献类型：
--
作者：
Davis, RW;Fuiman, LA;Le Boeuf, BJ
我们在一只北方象海豹身上安装了一个视频系统和数据记录器，以跟踪它的三维运动，并观察后鳍的推进动作。在6小时的记录中，海豹进行了20次潜水，90%的时间都在水下。平均潜水时间，最大深度和游泳速度为14.9分钟+/- 6.1 S.D.，289 m +/- 117 S.D.和1.1 m s（-1）+/- 0.12 S.D.，分别潜水时平均游泳距离为925 m +/- 339 S.D.，平均下降和上升角度为41度± 18 S. D。和50度+/-21 S.D.，分别潜水路径非常直，表明海豹在水下航行。我们根据推进划水之间的间隔确定了三种游泳模式：连续划水;划水滑行游泳;和长时间滑行。海豹从水面到平均深度为20米的地方进行连续划水，然后进行划水和滑行游泳。长时间的滑翔从平均深度60米开始，一直持续到潜水的底部。对于300米或更深的潜水，75%的下降时间用于长时间滑翔，10%用于划水和滑翔游泳，每次潜水的被动下降时间为5.9-9.6分钟。平均游泳速度变化不大的游泳模式，并不是一个很好的指标的推进努力。看来，海豹可以使用延长滑翔，以减少运输成本和增加潜水时间。高能量效率的运动可能有助于解释长时间和深潜，经常超过理论有氧潜水限制在这个物种。(C)2001 Elsevier Science Inc. All rights reserved.
We attached a video system and data recorder to a northern elephant seal to track its three-dimensional movements and observe propulsive strokes of the hind flippers. During 6 h of recording, the seal made 20 dives and spent 90% of the time submerged. Average dive duration, maximum depth and swimming speed were 14.9 min +/- 6.1 S.D., 289 m +/- 117 S.D. and 1.1 m s(-1) +/- 0.12 S.D., respectively. The distance swum during a dive averaged 925 m +/- 339 S.D., and the average descent and ascent angles were 41 degrees +/- 18 S.D. and 50 degrees +/- 21 S.D., respectively. Dive paths were remarkably straight suggesting that the seal was navigating while submerged. We identified three modes of swimming based on the interval between propulsive strokes: continuous stroking; stroke-and-glide swimming; and prolonged gliding. The seal used continuous stroking from the surface to a mean depth of 20 m followed by stroke-and-glide swimming. Prolonged gliding started at a mean depth of 60 m and continued to the bottom of dives. For dives to depths of 300 m or more, 75% of the descent time was spent in prolonged gliding and 10% in stroke-and-glide swimming, amounting to 5.9-9.6 min of passive descent per dive. Average swimming speed varied little with swimming mode and was not a good indicator of propulsive effort. It appears that the seal can use prolonged gliding to reduce the cost of transport and increase dive duration. Energetically efficient locomotion may help explain the long and deep dives that routinely exceed the theoretical aerobic dive limit in this species. (C) 2001 Elsevier Science Inc. All rights reserved.