This summary contains information on the biology of orcas (killer whales). The social structure of pods is discussed as well as the whale's diet.
The orca, also known as the killer whale, is a member of the dolphin family and is easily recognizable by its distinct black and white markings. Killer whales exist in all the oceans of the world in tight knit family groups known as pods. Each pod has its own distinct form of communicative sounds and behavior. Pods can typically travel over 100 miles in a single day following their food supplies in migration. There are two basic types of orca pods: the transient and the resident. Resident pods are large matrilineal family groups of whales that typically involve lifelong family bonds. A basic unit consists of the mother whale, all her dependent offspring (usually ten years of age and younger), and also her adult offspring as well.
Male orcas appear to remain with their mothers their entire lives, leaving to mate, and then returning to its family pod. Resident pods typically prefer a diet of fish, such as salmon, herring, or rockfish. The pod collectively works together to locate and catch a school of fish. Transient pods, on the other hand, consist of smaller family groups and regularly travel up to one hundred miles hunting for food. Their diet consists more of meat, feeding on seals, sea lions, and other whales. Male orcas tend to live an average of thirty years in the wild, while female orcas average about fifty years. (For more, see the Center for Whale Research, http://www.whaleresearch.com )