Killer Whales (Orcinus Orca) are distinctively marked black-and-white dolphins that exist in all oceans. Their behavior and biology has been intensively studied in populations that frequent waters of Washington State, British Columbia and southeastern Alaska%u2014and recently research has expanded west to include the central and western Aleutian Islands.
Decades of research in this region has uncovered three distinct populations: residents, transients and offshores. The two general types of killer whales, residents (fish-eaters) and transients (mammal-eaters), were first described off Vancouver Island, British Colombia. The third type of killer whale, offshores, are similar to residents, but can be genetically distinguished. The jury is still out on their foraging preference.
The comparison between resident and transient populations is quite contrasting. There are subtle differences in morphological appearance (e.g., such as dorsal fins), they are genetically different, their foraging strategies are different and each population has major differences in behavior and social organization. There are also differences in calls and use of acoustics while foraging.
* Killer whale call samples were obtained during research efforts credited to the following research partners and their publications:
Killer whales of southern Alaska
by Craig Matkin, Graeme Ellis, Eva Saulitis, Lance Barrett-Lennard and Dena Matkin Published in 1999.
Killer whales: the natural history and genealogy of Orcinus orca in British Columbia and Washington State
by John K. B. Ford, Graeme M. Ellis, Kenneth C., III Balcomb
Transients: mammal-hunting killer whales of British Columbia, Washington, and southeastern Alaska
by John K. B. Ford, Graeme M. Ellis