Distribution of killer whale pods in Prince William Sound, Alaska 1984-1996.

Thirteen years of encounter data (1984-1996) were used to examine killer wh ale distribution within Prince William Sound, Alaska. Four patterns of area use were found, which comprised differences between resident pods and tran sient groups and differences among resident groups. Resident pods frequente d large open passages, while transient groups used the narrow passages and bays in the southwest. This dichotomy likely reflects resident use of salmo n and transient use of pinniped prey resources, as well as the different fo raging strategies required for these prey types. Four resident pods (AB, AI , AJ, and AN) used Knight Island Passage more than other areas of the Sound ; two (AE and AK) used all areas of the Sound more evenly. Use of the Sound by the AT1 transient whales declined in the latter part of the study. Near shore foraging for pinniped prey by the AT1 transient whales was more commo n in areas where these whales spend a disproportionate amount of time, sugg esting that these areas were critical foraging habitat for them. No similar pattern emerged for Open-water Foraging for cetaceans by AT1 whales, nor f or foraging by the resident whales.