Check out our links to scientific papers, recommended books and other online resources about orcas and other cetaceans.

Most of what we know about the Southern resident orca community comes from a long-term demographic survey conducted by the Center for Whale Research on San Juan Island. The Center has been conducting photo-identification research on this orca population continually since 1976.

How long do orcas live? For a discussion of orca lifespans, please see Orca Lifespans.

For a general description of orca natural history focusing on the Southern Resident orca community, see Orcas of the Salish Sea.

For a history of the listing of Southern Resident orcas as Endangered under the Endangered Species Act, see Orcas In Our Midst, Volume 2: The Next Generation

For an introduction to orca natural history and the Salish Sea Watershed the Southern Resident orcas depend on, see Orcas In Our Midst, Volume 1: The Salish Watershed

All about Offshore orcas
All about Transient orcas

Some fascinating facts about orcas:

• Newborn orcas are 7-8 feet long, and weigh 3-400 lbs.

• Adult females worldwide are 17-24 feet, 5-9,000 lbs.

• Adult males worldwide are 20-28 feet, 8-12,000 lbs.

• Southern resident male orcas are 21-24 feet.

• Southern resident females are 18-21 feet.

• Orcas have a 17-18 month gestation period.

• Females usually have one calf every 4-5 years.

• Males often die in their 30s but may live to 60.

• Females may live to 100 or more.

• Males mature in their early teens, and are fully grown in their early 20s.

• An adult orca consumes 150-250 pounds of food a day.

• Southern Resident orcas rely on Chinook salmon for about 80% of their diet.

• The brain of an adult orca weighs 12-15 pounds, or about 4-5 times the size of human brains.

• Like all whales, orcas are voluntary breathers and need to be at least "half awake" at all times.

• Orcas are the largest members of the dolphin family, or delphinidae.

• Like all dolphins, orcas use sophisticated biological sonar, called echolocation.

• Orcas are found throughout the world's oceans, but tend to prefer the cooler, more productive polar and temperate waters.

• Orcas can swim up to 30 mph and travel 75-100 miles or more per day.

• Orcas have no predators.

• Orcas live in matrilineal family groups led by elder matriarchs.

• Two or more matrilines may form a pod.

• The J, K and L pods which frequent Puget Sound are known as the Southern Resident community, or SRKW.

• Both male and female offspring typically remain with their maternal family for life.

• Genetic evidence indicates that mating occurs between, and usually not within, matrilines.

• Each orca in the Southern Resident community is photographically identified each year by the shape of the dorsal fin, and gray pigmentation, called the "saddle patch" behind and below the dorsal fin.

• Several pods may belong to a clan that shares certain vocalizations; several clans may associate as a community.

• A pod's or maternal family's unique repertoire of calls is called a dialect.

• • When pods of the same clan or community meet after separation, they often intermingle vigorously.

• Communities remain apart from one another and use completely distinct vocalizations even when sharing the same habitats.

• Orcas are found throughout the world's oceans, but tend to prefer the cooler, more productive polar and temperate waters.

• A wide variety of types of orcas have been observed.

• "Residents," eat only fish; "Transients," eat only mammals, and "offshores," found several miles from shore, eat sharks.

• Other orca communities worldwide have different diets.

Orca Network's Whale Sighting Network covers the south end of the Salish Sea, from Victoria to Vancouver, BC and from the San Juan Islands to Seattle and Olympia and south Puget Sound. The Sighting Network is comprised of volunteers who observe and report on the travels and behaviors of both Resident and Transient orcas, as well as gray whales, humpbacks, and other cetaceans in the area.