生活在南極洲海域的虎鯨想出了一條捕捉海豹的機智且致命的“毒計”,。
當發(fā)現(xiàn)一只在大塊浮冰上游蕩的海豹后,，成群的虎鯨便會沖向浮冰，它們的尾巴會協(xié)調(diào)一致地擺動,，為的是產(chǎn)生一個波浪,，進而將海豹打入水中。
如果它們在一開始無法成功,，這些虎鯨會無情地折回來并送去一連串的波浪,，它們甚至會改變浮冰的位置或破壞浮冰，以便增加成功的幾率,。
一旦這只倒霉的海豹落入水中,，虎鯨會成群結(jié)隊地追捕它直至將其殺死——鯨魚會向海豹吹出大量氣泡以使其暈頭轉(zhuǎn)向,，并在水下拖拽它的后鰭足直至海豹因精疲力竭而溺亡,。之后，虎鯨會用卓越的精度將自己的獵物肢解,，并分享這頓美餐,。
來自美國加利福尼亞州圣地亞哥市國家海洋與大氣管理局（NOAA）下屬西南漁業(yè)科學中心的海洋生物學家Robert L. Pitman和John W. Durban,，日前在《海洋哺乳動物科學》雜志上描述了22次這種通過波浪沖刷的攻擊方式。
研究人員以前只記錄了5次這樣用波浪沖刷捕獵的過程,，并且他們假設這是一種不常見的情況,。然而新的論文報告說，波浪沖刷方式顯然是一群虎鯨主要的狩獵策略,，研究人員將它們稱為“浮冰虎鯨”,，并且它們可能是獨一無二的。
事實上,，這種行為可能是這一群虎鯨最典型的特征,。在2010年發(fā)表的一篇論文中，研究人員和同事描述的遺傳學證據(jù)意味著至少有3個不同的虎鯨種群,，而非像之前假設的那樣只有一種,。浮冰虎鯨屬于他們所提出的新物種之一。
虎鯨又名逆戟鯨,，是一種大型齒鯨,，身長為8～10米，體重9噸左右,，背呈黑色,，腹為灰白色，有一個尖尖的背鰭,，背鰭彎曲長達1米,，嘴巴細長，牙齒鋒利,，性情兇猛,，是企鵝、海豹等動物的天敵,。有時它們還襲擊其他鯨類,，甚至大白鯊，是海中的霸王,。（生物谷Bioon.com）
生物谷推薦原文出處：
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.”
