Humpback whales can pass a good idea on to each other in much the same way as humans, scientists have learned.
A new hunting technique invented after the whales were hit by a food crisis has spread to 40% of the humpback population off New England, US.
The whales were forced to find new prey after stocks of their preferred food, herrings, crashed in the early 1980s.
Humpback whales forage for food by blowing bubbles under water to confuse shoals of fish and herd them together. The bubble nets bring the fish to one place and make them easier to catch.
But in 1980, one whale was spotted feeding in a completely new manner. The whale slapped the water's surface a few times with the end of its tail and only then dived down to bubble feed. By 2007 the technique, known as lobtail feeding, had caught on among humpback whales in the Gulf of Maine.
Scientists believe it was devised to target a particular prey, sand lance. Use of the technique is concentrated at Stellwagen Bank, where the fish spawn and are especially abundant.
Dr Luke Rendell, one of the researchers from the University of St Andrews in Scotland, said: "Our study really shows how vital cultural transmission is in humpback populations - not only do they learn their famous songs from each other, they also learn feeding techniques that allow them to buffer the effects of changing ecology."
The findings are published in the latest edition of the journal Science. Data for the study were collected by naturalist observers on whale watching vessels that patrol the Gulf of Maine each summer.
By studying 30 years of observations, the scientists tracked the spread of lobtail feeding behaviour through the whale community.