SCIENCE WHALE'S SCHEME : SOCIAL COOPERATION [ 2 ]

MICHAEL WEISS - an author of the study who is the research director for the Center for Whale Research in Washington State, said the Southern Residents had long used their intelligence and social skills to adapt to a challenging environment.

The group of 73 orcas, often called killer whales, was listed as endangered in 2005.

Kelp is not that hard to find in the waters near British Columbia and Washington State, where the orcas generally stay. But they were not just grabbing any old floating stalk.

They used their teeth to break off pieces, which were usually about two feet or 60 centimeters, long.

An orca would then carry it to a partner, and the two would rub against each other to roll the kelp against their skin, if the stalk slipped away, the whales would sometimes take turns to repositioning it to start the glide again.

The behaviour appears to play a role in socializing and grooming. According to the researchers, it would also be a technique developed by the orcas to exfoliate dead skin

The World Students Society thanks Jacey Fortin.