Killer
whale Research > Diet
Killer whale diet (and you thought you were a picky eater!)
 Resident
and transient forms of killer whales exhibit striking differences in their
diet. While residents feed exclusively on Pacific salmon (Oncorhynchus
spp.), transients only feed on warm-blooded prey – marine mammals
in most cases, with the occasional seabird on the menu. In addition, dietary
preference varies between different transient populations that choose
to feed on different marine mammal species.
By following groups of transients, using acoustic monitoring to record
their every kill, attack, and harassment of marine mammals, we are able
to acquire a better understanding of the diet composition of the different
killer whale populations off the coast of Alaska and British Columbia.
This, in turn, will allow us to determine the impact of killer whale predation
on marine mammal populations, and to delineate the role of killer whales
in the North Pacific ecosystem with greater accuracy.
The following table demonstrates what studies of the dietary preference
of transient populations in various locations have revealed so far:
| |
Transient
type |
Principal
diet |
%
of Steller attacks observed |
Research
team |
| British
Columbia |
West Coast Transients |
Harbor seals. Steller sea lions make up only a
small proportion (7%) of the diet. Grey and minke whales are occasionally
killed |
7% |
John Ford
Graeme Ellis
Lance Barrett-Lennard, Volker Deecke |
| Southeast
Alaska |
West Coast Transients |
Harbor seals, despite a greater preference (17%
of recorded kills) for Steller sea lions |
17% |
Jan Straley, Dena Matkin and Volker Deecke |
| Prince
William Sound |
AT1 |
Harbor seals and Dall’s porpoises |
none observed |
Craig Matkin |
| Gulf
of Alaska |
Gulf of Alaska |
Steller sea lions |
79% |
Craig Matkin and Lori Mazzucca |
| Aleutian
Islands |
? |
Minke, grey and humpback whales and
northern fur seals |
none observed |
Lance Barrett-Lennard and Craig Matkin |
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Mammal Research Consortium Publications
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