虎鯨捕食竟靠複雜的團隊合作
The seal feels perfectly safe lying on the Antarctic ice even if it is surrounded by a pod of killer whales.
對於海豹來說，即使有一大羣虎鯨在他周圍，躺在南極的冰面上他也覺得異常完美。
But within minutes it has been knocked into the water in a clever team tactic before being killed.
但是幾分鐘之內，被殺之前，他就會按照一定次序進入水中。
These astonishing pictures show how the sea predators work together - and the technique provides meals for killer whales three out of every four times they use it, according to scientists.
這一系列讓人吃驚的圖片都展示了海洋捕食者是怎樣合作的，而據科學家們書，虎鯨每頓飯都要用三四次這樣的方法進行捕食。
Research has also found that the mammals - around 26ft in length and weighing more than six tonnes - carefully butcher the prey underwater, co-operating as they skin and dissect the seals.
研究還發現這種重達六噸的哺乳類動物，在水底捕食海豹的時候，也會互相合作。
Dr Robert Pitman, a marine scientist at the National Oceanic and Atmospheric Administration in California, took the stunning images of the pod going in for the kill.
在加利福尼亞州國家海洋和大氣管理局的海洋科學家羅伯特·皮特曼博士，拍到了這羣動物如何一起進行獵殺的圖片。
He said: 'The killer whales were very good at knowing in advance if they were going to be able to wash a seal off a floe and they were always successful in getting the seal into the water.
他說，“虎鯨都知道將海豹趕下浮冰他們就成功了，而且他們也很擅長這麼做，非常輕鬆的就能把海豹弄到水裏去。”
'A couple of times the seal was washed off but managed to escape in the confusion, but not very often. From killer whale studies elsewhere we expected this kind of social interaction but it was the canniness of their hunting tactics that blew us away.'
“有幾次海豹會試圖逃跑，但是這種情況並不會經常發生。虎鯨讓我們意識到了這種社會關係的重要性，但是他們捕食獵物時的機警和迅速還是讓我們所有人都感到吃驚。”
Dr Pitman and his colleague Dr John Durban helped a BBC film crew capture their behaviour for the TV documentary series Frozen Planet, to be shown later this month.
皮特曼博士和他的同事，約翰·德班博士，幫助BBC拍攝的虎鯨捕食獵物的紀錄片，冷凍星球，將在這個月的晚些時候上映。
They spent weeks tracking and recording the hunting behaviour in the pack ice off the coast of the Antarctica Peninsula.
他們花了幾個星期的時間在南極洲的半島的冰蓋上跟蹤和記錄虎鯨的狩獵的行爲。
The whales prefer weddell seals, which can be up to 11 feet long,rather than the more aggressive crabeater and leopard seals.
鯨魚們似乎都喜歡吃韋德爾海豹，他們能有11英尺長，比一般的黑鱈魚和海豹都更難捕獲。
Dr Pitman told the Sunday Telegraph that the whales deal with seals who try to hide among the ice after being knocked into the sea by creating shock waves with their tails to knock them out into the open water.
皮特曼博士告訴週六郵報說，鯨魚處理那些試圖隱藏在被撞擊的冰塊後的海豹，他們會用他們的尾巴製造波浪，並將海豹們趕到開放海域中去。
He said: 'The whales also blew streams of bubbles under the seals apparently trying to get them to bolt into open water where they wouldn't have a chance against the waiting killer whales.'
博士還說，“鯨魚也在海豹旁製造很多泡泡來吸引他們進入開放的海域，否則當虎鯨出現的時候，他們就沒有任何機會了。”
