Killer Whale 



Orcinus orca (Linnaeus, 1758 



Killer whales have been observed in all areas and oceans. The 

 prevalent understanding of their distribution, often recounted, is that 

 while they may be encountered virtually anywhere in marine vvaters 

 world wide they are most abundant m colder waters of both hemi- 

 spheres, with centers of greatest abundance within about 800km ot 

 continents. In some areas they appear to be migratory while m others 

 they are apparently present year-round. The general patterns of dis- 

 tribution and movement worldwide have often been described. But for 

 most regions there are few published details on the distribution, 

 abundance, seasonal movement patterns and habitat use. 



The eastern North Pacific is the exception to that rule. Here, killer 

 whales are known from the Chukchi Sea south to the equator with no 

 major hiatuses in distribution apparent. Reviews ot literature and 

 analyses of results of major observation programs have characterized 

 relative abundance by major oceanic (eastern tropical Pacific) and 

 coastal (Alaska) regions. Further, the dynamics ot "populations" in 

 areas from northern Washington to southern Alaska are under study 

 and reasonably well known. These detailed population studies have 

 been based largely on monitoring ot n,iturallv tagged individuals using 

 high quality black and white photographs ot the dorsal fin and post- 

 dorsal-fin saddle and on examination of acoustic recordings for evi- 

 dence of dialects. Such studies, begun in inland marine waters of 

 Washington and British Columbia in the early 1970s, have recently 

 been conducted in Southeast Alaska and southern Alaska and are being 

 extended with less intensity to waters south of the Strait ot Juan de 

 Fuca, Washington, along the west coast of North America. 



From the above studies, the current dogma is that some pods and 

 populations of killer whales are "resident", occurring all or most of the 

 year in relatively limited "territories" or "home ranges ', while others 

 are "transient", ranging far and therefore likely to occur only spo- 

 radically at any given site. The best described "resident" pods are 

 known from enclosed inland marine waters with high productivity, 

 such as those in Prince William Sound, in portions ot Southeast 

 Alaska, in the Strait of Georgia, around Vancouver Island and in Puget 

 Sound. Transients are most often found on the outer coasts and are 

 found in general in lesser densities overall. 



Along the coast of Calitornia, killer whales are ottcn sighted well 

 out to sea, but some move into kelp beds and into bays and inlets, as 

 well. Thev are seen frequently along the coast of Baja California, 

 particularly near island pinniped rookeries. For that reason, one might 

 reasonably expect to meet them frequently around the pinniped-rich 

 areas in the SCB and CINMS. It is surprising, therefore, that there are 

 relatively kv.' confirmed records from those regions. A recent review 

 uncovered only 35 confirmed sightings in the SCB, Santa Barbara to 

 San Diego, for the decade 1974-1984. A high proportion of those were 

 recorded from nearshore areas around the northern Channel Islands. 

 Killer whales have been seen in the SCB in most months but with 

 slightly higher frequency in autumn and spring. 



After examining the limited data available from this area one 

 researcher postulated that there were nvo subpopulations in the SCB, 

 one operating in the region of the southern islands and adjacent 

 mainland, the other in the vicintiry of the northern islands fAnacapa, 

 Santa Cruz, Santa Rosa and San Miguel) and the adjacent mainland, 

 Port Hueneme to Point Conception. Another worker postulated that 

 there were several "resident" pods and several "transient" ones in the 

 SCB, supporting his hypothesis with a handful of photo-identified 

 individuals resighted after the initial identification. One of us (SL) 

 wrote some years ago that killer whales are seen infrequently in the 



FiGUKE lb. This male killer whale, one of seven encountered in early March 

 1984 off Anacapa Island, provided thrills to the passengers and crew of the Wi 

 Smn and the Shrarwtttcr. (Photos courtesy of T. Donnally.) 



Figure 27. An immature (jjo cm) female killer whale stranded at Willow 

 Cove, on the southeastern side of Santa Cruz Island, about 2 June 1973. We 

 are aware of only four such scrandings of this species in the SCB since 1907, 

 indicative of the relati%'ely low densities occurring in and near the CINMS. 

 (Photo by W. Philbin.) 



