The seal feels perfectly safe lying on the Antarctic ice even if it is surrounded by a pod of killer whales. But within minutes it has been knocked into the water in a clever team tactic before being killed. 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.
Research has also found that the mammals—around 26ft in length and weighing more than six tons—carefully kill the prey underwater，co-operating as they skin and dissect the seals. Dr Robert Pitman, a marine scientist at the National Oceanic and Atmospheric Administration in California, took the shocking images of the pod going in for the kill. 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. 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.”
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. They spent weeks tracking and recording the hunting behaviour in the pack ice off the coast of the Antarctica Peninsula. The whales prefer Weddell seals, which can be up to 11 feet long, rather than the more aggressive crabeater and leopard seals. 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.
He said, “The whales also blew streams of bubbles under the seals apparently trying to get them into open water where they wouldn't have a chance against the waiting killer whales.”
【小题1】Which of the following is true about the killer whales' hunting tactic?| A．They kill the whale before knocking it into water. |
| B．They use the tactic three or four times before succeeding. |
| C．They make astonishing shows to have other sea predators work together. |
| D．They manage to earn their meals with the tactic in most cases. |
| A．worked as a reporter at BBC |
| B．filmed Frozen Planet all by himself |
| C．followed and recorded the killer whales for weeks |
| D．conducted studies on killer whales elsewhere in advance |
| A．use their skin to interact | B．are normally 11 feet long |
| C．often have seals run away in the open water | D．take advantage of bubbles when hunting |
| A．A TV documentary series on seals. | B．The canny team tactics of killer whales. |
| C．Dr Robert Pitman's latest study. | D．The special living habits of killer whales. |
