Mitochondrial DNA sequences support the theory that these are recently diverged separate species.More recently, complete mitochondrial sequencing indicates the two Antarctic groups that eat seals and fish should be recognized as distinct species, as should the North Pacific transients, leaving the others as subspecies pending additional data. Their conservation status is not precise and clear due to lack of statistically relevant data. Foraging strategies of sympatric killer whale (Orcinus orca) populations in Prince William.

But they see and hear very well. Type A orcas get up to 31 feet in length and hunt minke whale. Because of their generally large size, orcas are sometimes mistaken as whales. Their distribution is around the entire Antarctic continent being sighted in mostly open water. 9Jones, I. M. (2006). A male killer whale can reach 32 feet (9.6 meters) in length, and weigh up to nine tons. Dietary specialization in two sympatric populations of killer whales (Orcinus orca) in. response to depletion of the great whale populations?. Their biggest threats are oil spills, as they are widely distributed and frequently inhabit both open and coastal waters like the Pacific Northwest region, and the United States international waters in general. A., M. V. Ivashin, V. P. Savusin and F. E. Zelenaya. for killer whale predation on Steller sea lions in British Columbia and Alaska. Killer whales have a diverse diet, although individual populations often specialize in particular types of prey. 13Ford, J. K. B., G. M. Ellis, C. O. Matkin, M. H. Wetklo, L. G. Barrett-Lennard and R. E. Withler. 14Pitman, R. L., and P. Ensor. In the Southern Ocean, there are five orca ecotypes: Antarctic Type A, Pack ice Type B large form, Gerlache Type B small form, Ross Sea Type C, and Sub-Antarctic Type D. mitigation solutions. Type 2 orcas grow to approximately 8.5 meters. Two dwarf species, named Orcinus nanus and Orcinus glacialis, were described during the 1980s by Soviet researchers, but most cetacean researchers are skeptical about their status, and linking these directly to the types described below is difficult.

The research supported a proposal to reclassify the Antarctic seal- and fish-eating populations and the North Pacific transients, should be recognized as distinct species, leaving the remaining ecotypes as subspecies. coastal British Columbia and adjacent waters. (2006). Sound, Alaska.

“Gerlache” orcas of the smaller type B form are about half the size of “pack ice” orcas. A. Estes, D. P. DeMaster, D. F. Doak, T.. M. Williams and R. L. Brownell.

Offshores typically congregate in groups of 20–75, with occasional sightings of larger groups of up to 200.Currently, little is known about their habits, but they are genetically distinct from residents and transients. They're apex predators - they're on top of the food chain.

62(2):287-95. Offshores are slightly smaller than both residents and transients with continuously rounded dorsal fins and closed saddle patches and specialize in feeing on Pacific sleeper sharks (. Photo-identification of individual killer. 22Foote, A. D., J. Newton, S. B. Piertney, E. Willerslev and M. T. P. Gilbert. coastal British Columbia and adjacent waters. pp 145-162. A northeast Pacific offshore killer whale (. 21Tixier, P., N. Gasco, G. Duhamel and C. Guinet. An ecotype is “a population of a species that survives as a distinct group through environmental selection and isolation and that is comparable with a taxonomic subspecies” (Merriam-Webster). Transients generally travel in small groups, usually of two to six animals, and have less persistent family bonds than residents. There are ten orca ecotypes around the world. Although large variation in the ecological distinctiveness of different killer whale groups complicate simple differentiation into types, research off the west coast of Canada and the United States in the 1970s and 1980s identified the following three types: Resident: These are the most commonly sighted of the three populations in the coastal waters of the northeast Pacific. Unlike type A, type B are observed in the pack ice during winter.