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| Vulnerable. The orca, or "killer," whale is the largest member of the dolphin family. Orcas have long, rounded bodies with large dorsal fins at the middle of their backs. Their black bodies are marked with white patches on the underside and near the eyes. The average male orca grows to 23 feet long and weighs 7 to 10 tons. Females average 21 feet long and weigh 4 to 6 tons. The worldwide population of orcas is unknown. Orcas live 30 to 50 years in the wild. 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 found in both coastal waters and open ocean. 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 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. Orca gestation is 13 to 16 months. A calf is born in autumn weighing almost 400 pounds and measuring up to 7 feet in length. A calf will remain with its mother for at least two years. 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. *CITES, Appendix II, Marine Mammal Protection Act *Convention on International Trade in Endangered Species of Wild Fauna and Flora, an international treaty with more than 144 member countries. Appendix I species cannot be traded commercially. Appendix II species can be traded commercially only if it does not harm their survival.
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