Orca (Orcinus orca)

Other names: Killer whale

Description: Orcas, also known as killer whales, are the largest species in the dolphin family. The males can grow up to 32 feet long and have a dorsal fin thats 6 feet tall. They are a pure black with a white underside and a white patch on each side of their face. Killer whales are highly intelligent and social animals. They travel in pods, and each group of orcas has distinct behaviors and vocalizations that create unique “cultures”. They hunt cooperatively in groups like a wolf pack, and can take down prey as large as great white sharks and whale calves, making them the top predators of the ocean.

Habitat: Orcas are found around the world, but each subgroup or “ecotype” has a territory that they inhabit. In the Pacific North West the resident pods range from the Puget Sound to Southeastern Alaska, staying close to shore. The transient ecotype ranges from SE Alaska to Southern California and can been seen near shore or several miles out. Offshore orcas are found in the open ocean across the Pacific. All three ecotypes can occasionally be seen on the Oregon Coast.

Diet: The diet of orcas is dependent on what subgroup they belong to. The resident killer whales of the Puget Sounds eat exclusively chinook salmon. Transient orcas tend to eat more marine mammals like seals, sea lions, and whale calves. The least is known about offshore pods, but they are believed to primarily eat fish.

Tide Pool Tidbits:

• Orcas have a matriarchal social structure.

• Females have a longer life span than males, and are one of the few species, besides humans, that go through menopause. Elderly female orcas continue to assist the pod by helping her daughters rear young.

• Although the world wide population of orcas is stable, the Southern resident killer whales are listed as endangered due to decreased reproductive rates and increased infant mortality in recent years. The chinook salmon population has decreased in the Puget Sound and with less food for the Southern resident killer whale population is decreasing as well.

References: NOAA, ODFW, Port Townsend Marine Science Center