We’re in a bay off the coast of Alaska, where groups of Killer whales are hunting for salmon. I’m Jim Metzner and this is the Pulse of the Planet, presented by the American Museum of Natural History.
Craig Matkin is Director of the North Gulf Oceanic Society.
“These fish eating Killer whales seem dependent on the salmon, much as the aboriginal people were in these northern areas, years ago. They follow the schools of salmon into the sound during the summer months and feed on particular species of salmon. And they chase these fish and corral them and eat them.”
Slapping the surface of the water with their tails and flippers, a pod of killer whales methodically surrounds a school of salmon and eats its fill. Then, using underwater echolocation signals – those clicking sounds that we hear – the whales search for new sources of prey.
“You can hear all the echolocation clicks. These animals are actively feeding. They’re probably spread out over several miles. The clicking sounds that you hear: that indicates that they’re also searching, searching possibly for salmon schools.”
The echolocation signals bounce off the moving schools of salmon and return to the whales, helping them pinpoint the location of their prey.
“As they zero in on a fish, the clicks get closer and closer together, so that it sounds more intense. Sometimes it sounds like a high speed typewriter.”
Killer whales will remain in the bays near Alaska until winter, when they and the salmon will travel farther offshore. Besides salmon, Killer Whales feed on dolphins and seals, but they’re typically not known to attack humans.
Additional funding for Pulse of the Planet has been provided by the National Science Foundation. I’m Jim Metzner.