A young killer whale is using fish as bait to catch seagulls, and is teaching his companions the same method.

First, the young whale spits regurgitated fish onto the surface of the water, then sinks below the water and waits.

If a hungry gull lands on the water, the whale surges up to the surface, sometimes catching a free meal of his own.

Michael Noonan, a professor of animal behavior at Canisius College in Buffalo, N.Y., made the discovery by accident while studying orca acoustics, reports The Associated Press.

"One day I noticed one of the young whales appeared to have come up with a procedure for luring gulls down to the pool," the professor says. "I found it interesting so I noted it in my log."

Within a few months, the whale's younger half brother adopted the practice, which they used repeatedly. Eventually the behavior spread and now five Marineland whales supplement their diet with fresh fowl, the scientist says.

"It looked liked one was watching while the other tried," Noonan says of the whale's initial behavior.

The capacity to come up with the gull-baiting strategy and then share the technique with others - known as cultural learning in the scientific world - was once believed to be one of those abilities that separated humans from other animals.

But biologists have since proven certain animals, including dolphins and chimps, do this.