Killer Whale (Orcinus orca)
Background Information
Image courtesy of Webshots
General:
The species Orcinus orca, is a member of the Odontoceti, or toothed whales; however, the killer whale is the largest living species of dolphin and not actually a true whale (Animal Planet, 2002; Hoelzel, 1994).
The capabilities and intelligence of the orca may rank it high among all mammals (Norris, K., 1958). A geographic mosaic of killer whale populations, some sympatric and others allopatric, exists in the world’s oceans; each may have distinctive foraging and behavioral traditions that have evolved over long periods, which in turn has led to some degree of social insularity, reproductive isolation, and genetic discreteness (Ford, 1998).
Description:
Killer whales have distinctive black bodies with white patches, particularly over the eyes and around the belly. Females grow to about 26 feet long (8 meters); males, 28 feet (8.5 meters) (Hammers, 2003). They are long-lived, with estimated maximum ages of 80-90 years for females and 50-60 years for males (Brault, 1993). The horizontal flukes can propel the whale through the water with great power and speed (Norris, K., 1958).
Habitat and Habitat Distribution:
Killer whales can adapt to almost any conditions and appear to be at home in both open sea and coastal waters (Cetacea, 2004). Killer whales are world-wide in distribution, occurring most commonly in the waters of the Arctic and Antarctic regions but wandering into tropical seas in smaller numbers. They frequent coastal waters along the continental shelf and can be found along the entire Alaskan coastline except where the pack ice excludes them because of their dorsal fin (Animal Planet 2002; Norris, K., 1958).
Image courtesy of Expedition Trips
In the Pacific Northwest, researchers categorize groups of killer whales into transient-type whales (smaller groups that were encountered sporadically, did not associate with the larger groups, and were thought to be in transit from one area to another) and resident-type whales (comparatively large groups of whales that had stable composition and could be found predictably in certain areas) (Ford, 1998) based on physical and behavioral characteristics. A third type, offshore whales, have been identified but little studied (Brault, 1993; Norris, S., 2002).