London: Killer whales have hit upon a smart way of catching their unsuspecting prey. They create large waves in tandem to knock their prey into the water so they can hunt it.

For instance, a seal perching on a solid block of floating ice on the Antarctic Ocean would be knocked into the water by the force of the waves created by the whale pack.

Scientists who discovered the technique say it is so effective that it produces a meal for the whales three out of every four times they use it, reports say.

They have also found that the killer whales, which can be around 26 feet long and weigh more than six tonnes, carefully butcher their prey underwater, co-operating to skin and dissect the seals once they have killed them.

The findings are helping to provide a growing understanding of just how sophisticated the behaviour of killer whales can be.

Robert Pitman, marine scientist at the National Oceanic and Atmospheric Administration in California, 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,' added Pitman.

The scientists spent several weeks tracking and recording the hunting behaviour of killer whales in the pack ice off the coast of the Antarctica Peninsula.