The orca, or "killer," whale is the largest member of the dolphin family.
Endangered in Oregon, Washington, and California.
Population: The worldwide population of orcas is unknown.
Threats: Recent studies have found that orcas are among the most contaminated marine mammals in the world. Pollution and chemical contamination make orcas more susceptible to disease and likely cause reproductive difficulties.
Orcas live 30 to 50 years in the wild.
Although they are found in all oceans of the world, orcas are most common in the Arctic and Antarctic and are often spotted off the west coast of the United States and Canada.
Orcas are highly social animals that travel in groups called pods. Pods usually consist of 5 to 30 whales, although some pods may combine to form a group of 100 or more. Orcas establish social hierarchies, and pods are lead by females. The animals are thought to have a complex form of communication with different dialects (slightly different language) from one pod to another.
Like dolphins, orcas use echolocation—bouncing sound off of objects to determine their location—to hunt, and use a series of high-pitched clicks to stun prey. Orcas feed on fish, squid, birds, and marine mammals. Orca pods often work together to catch a meal. Pods sometimes will force many fish into one area and take turns feeding or will beach (slide out of the water onto the shore) themselves to scare seals or penguins into the water where other whales are waiting to feed.
Orcas are found in Katmai National Park and Preserve, AK; Kenai Fjords National Park, AK; Wrangell-St. Elias National Park and Preserve, AK; Olympic National Park, WA.
1. "Orcas." 2009. The Humane Society of the United States website. 22 Mar. 2010 < http://www.hsus.org/marine_mammals/a_closer_look_at_marine_mammals/orcas.html >
2. "Killer Whale (Orcinus orca)." NOAA Fisheries Office of Protected Resources. 2010. National Oceanic and Atmospheric Administration website. 22 Mar. 2010 < http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/killerwhale.htm >
Updated: March 22, 2010