SEATTLE -- A roving pack of transient killer whales took out an adult gray whale over the weekend in a full-on hunt witnessed by a boatful of whale watchers.
Recorded live by one of the tourists, the kill was unusual only in that the orcas went after an adult gray. The orcas usually prey on gray whale calves as the young animals cruise the outer coast with their mothers.
The orcas cued up their hunt in Saratoga Passage on Sunday afternoon, between Camano and Whidbey islands.
"Right in our front yards we literally have these major predators. It's not something you have in many other areas," said Brad Hanson, biologist at the National Marine Fisheries Service in Seattle.
Transient killer whales mostly frequent the waters of British Columbia, but also are found in Puget Sound, especially when they are chasing prey.
They prefer mammals -- seals, sea lions and even whales. The orca whales in Puget Sound's southern resident population, in contrast, eschew mammals and eat only fish, particularly chinook salmon.
Orca diet is cultural: The animals learn what is food for them from their families, and pass it along to the next generation.
Dr. Hanson was out on the water watching the transients hunt Sunday.
In addition to the gray whale, the pack also took on at least one seal.
The adult orcas hung back during some of the hunt, to allow younger animals to practice their hunting skills.
"They were taking a few runs at it, while the adults were circling nearby, standing off," Dr. Hanson said.
It is not unusual for whale biologists to discover rake marks on gray whales, the result of tangling with killer whales. Adult grays are no easy mark.
Big and powerful, they are capable of striking powerful blows with their flukes to defend themselves.
There are about 20,000 gray whales in the population that regularly migrates up and down Washington's coast. Another very small population of grays also frequents the inner waters of Puget Sound and the Strait of Juan de Fuca with such regularity the locals sometimes name them.