Eavesdropping Seals

Harbor seals can tell dangerous orcas from the harmless ones

• Mark Cheater
• Apr 01, 2003

WHEN IT COMES to enemies, harbor seals have an ear for language. New research shows that the seals can tell the difference between the dialects of dangerous groups of killer whales and those whales that pose no threat.

Killer whales in the Pacific Northwest fall into two categories: residents that live in stable groups and eat only fish, and wanderers that prey on other mammals—often harbor seals. The two kinds of killer whales rarely interact, and have distinct sets of high-pitched calls they use to communicate underwater.

When researchers played taped calls of the harmless, fish-eating whales to a group of harbor seals off Canada’s western coast, few seals reacted. But when calls of the predatory transients were played, more than 40 percent of the seals dived and swam away from the underwater speaker.

Says the study’s lead researcher, Volker Deecke of the University of British Columbia in Canada, "Animals are capable of amazing learning feats when their lives are at stake!"