It’s dinnertime for the killer whales. Unhurriedly, the 28 members of the pod skirt the edges of a school of coho salmon, gradually forcing the fish into a closely packed mass and assuring the whales an easy catch. As they work, the whales talk volubly among themselves, seemingly exchanging information.
Twenty miles to the south, the dinner bell has also rung for another, much smaller group of killer whales. Their hunt is different from that of the salmon eaters. These orcas are quietly approaching a basaltic shelf used as a resting place by Steller’s sea lions. The seal hunters disdain fish; they kill and eat only marine mammals. They travel alone or in twos or threes rather than in the large, freewheeling aggregations that characterize their salmon-eating kin. And they are usually laconic. They never speak at all while hunting. What conversation they do have is reserved for the moments during and just after the kill, when the spoils of meat are divided among the group.
The differences between these two groups have led researchers to believe that the life of the killer whale--Orcinus orca--is a complex one, based on traditions and cetacean-style family values. Apparently these whales exist within the context of a genuine culture--or more appropriately, cultures. Orca societies are in no way similar to human societies, but they are societies nevertheless, says whale biologist Ken Balcomb.
This view has taken shape gradually over the past 20 years as researchers have gathered more and more information on the killer whale populations of the Pacific Northwest. Their data are of essentially two types: photo identification of individual whales, and underwater recordings of the sounds they make. Orcas may look alike to the layperson--black with a white belly patch extending up the flanks, a white patch behind the eye and one behind the dorsal fin, and a body up to 30 feet long that weighs in the neighborhood of five to six tons--but individual differences are obvious to the veteran researcher. The shape and condition of the dorsal fin and the size and shape of skin patterns vary from whale to whale, says Balcomb. When you examine photos, each whale looks very distinctive.
Just as photos have allowed Balcomb and his fellow researchers to follow the lives of individual whales, hydrophones have allowed them to document the linguistic and aural lives of the various groups. Together these two approaches have helped lead researchers to the conclusion that two separate populations of killer whales inhabit the waters off British Columbia and southeastern Alaska, populations so different that they are essentially like different species.
