生活在南极洲海域的虎鲸想出了一条捕捉海豹的机智且致命的“毒计”。
当发现一只在大块浮冰上游荡的海豹后，成群的虎鲸便会冲向浮冰，它们的尾巴会协调一致地摆动，为的是产生一个波浪，进而将海豹打入水中。
如果它们在一开始无法成功，这些虎鲸会无情地折回来并送去一连串的波浪，它们甚至会改变浮冰的位置或破坏浮冰，以便增加成功的几率。
一旦这只倒霉的海豹落入水中，虎鲸会成群结队地追捕它直至将其杀死——鲸鱼会向海豹吹出大量气泡以使其晕头转向，并在水下拖拽它的后鳍足直至海豹因精疲力竭而溺亡。之后，虎鲸会用卓越的精度将自己的猎物肢解，并分享这顿美餐。
来自美国加利福尼亚州圣地亚哥市国家海洋与大气管理局（NOAA）下属西南渔业科学中心的海洋生物学家Robert L. Pitman和John W. Durban，日前在《海洋哺乳动物科学》杂志上描述了22次这种通过波浪冲刷的攻击方式。
研究人员以前只记录了5次这样用波浪冲刷捕猎的过程，并且他们假设这是一种不常见的情况。然而新的论文报告说，波浪冲刷方式显然是一群虎鲸主要的狩猎策略，研究人员将它们称为“浮冰虎鲸”，并且它们可能是独一无二的。
事实上，这种行为可能是这一群虎鲸最典型的特征。在2010年发表的一篇论文中，研究人员和同事描述的遗传学证据意味着至少有3个不同的虎鲸种群，而非像之前假设的那样只有一种。浮冰虎鲸属于他们所提出的新物种之一。
虎鲸又名逆戟鲸，是一种大型齿鲸，身长为8～10米，体重9吨左右，背呈黑色，腹为灰白色，有一个尖尖的背鳍，背鳍弯曲长达1米，嘴巴细长，牙齿锋利，性情凶猛，是企鹅、海豹等动物的天敌。有时它们还袭击其他鲸类，甚至大白鲨，是海中的霸王。（生物谷Bioon.com）
生物谷推荐原文出处：
Marine Mammal Science DOI: 10.1111/j.1748-7692.2010.00453.x
Cooperative hunting behavior, prey selectivity and prey handling by pack ice killer whales (Orcinus orca), type B, in Antarctic Peninsula waters
Robert L. Pitman, John W. Durban
Keywords:Antarctica;hunting behavior;killer whale;Leptonychotes weddellii;Orcinus orca;prey handling;prey specialization;Weddell seal
Abstract
Currently, there are three recognized ecotypes (or species) of killer whales (Orcinus orca) in Antarctic waters, including type B, a putative prey specialist on seals, which we refer to as “pack ice killer whale” (PI killer whale). During January 2009, we spent a total of 75.4 h observing three different groups of PI killer whales hunting off the western Antarctic Peninsula. Observed prey taken included 16 seals and 1 Antarctic minke whale (Balaenoptera bonaerensis). Weddell seals (Leptonychotes weddellii) were taken almost exclusively (14/15 identified seal kills), despite the fact that they represented only 15% of 365 seals identified on ice floes; the whales entirely avoided taking crabeater seals (Lobodon carcinophaga; 82% relative abundance) and leopard seals (Hydrurga leptonyx; 3%). Of the seals killed, the whales took 12/14 (86%) off ice floes using a cooperative wave-washing behavior; they produced 120 waves during 22 separate attacks and successfully took 12/16 (75%) of the Weddell seals attacked. The mean number of waves produced per successful attack was 4.1 (range 1–10) and the mean attack duration was 30.4 min (range 15–62). Seal remains that we examined from one of the kills provided evidence of meticulous postmortem prey processing perhaps best termed “butchering.”
