Orca (Killer Whale)

A dolphin, not a whale

Despite the name, the killer whale is the largest member of the dolphin family. Males reach about 32 feet and six tons, with a dorsal fin that can stand six feet tall; females are smaller, around 23 to 28 feet. They can live long lives: females to 80 years or more, males to around 50 or 60.

Orcas live in family groups led by older females, and each population has its own dialect of calls and its own hunting culture, passed from mothers to calves. In the Pacific Northwest, grandmother orcas lead pods to the best salmon.

What orcas eat depends on who they are

Orcas as a species eat almost anything that swims, from herring to great white sharks to blue whales. But individual populations specialise. Along the West Coast there are three kinds: Resident orcas that eat fish, mostly Chinook salmon; Bigg's, or transient, orcas that hunt seals, sea lions, porpoises and whales; and offshore orcas that eat sharks and other fish far out at sea. They do not interbreed and they do not share meals.

Why the Southern Residents are endangered

The Southern Resident killer whales, the salmon-eating pods of Washington and British Columbia, numbered around 73 at the most recent counts, down from about 98 in the mid-1990s. They were listed under the Endangered Species Act in 2005. The causes are clear: too few Chinook salmon, vessel noise that makes it harder to hunt by sound, and pollutants such as PCBs stored in their fat.

Meanwhile Bigg's orcas in the same waters are thriving, because the seals and sea lions they eat have recovered. The difference between the two is the clearest lesson in the Pacific Northwest: the whales are only as healthy as their food.

A spy hop, and other behaviour

The photograph at the top of this page shows a spy hop: the whale holds itself vertically at the surface to see above the water, including the boat and the people on it. Orcas also breach, slap their tails, and ride the pressure wave of boats. All of it is best watched from the distance the law requires.