Orcas are found in both coastal waters and open ocean. Orcas feed on fish, squid, birds, and marine mammals. Orca pods often work together to catch a meal. 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.
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.