Killer Whale
Orcinus orca
Killer whales are members of the toothed whales (suborder
Odontoceti) that have highly encephalized brains. Dolphins,
porpoises, belugas, and narwhals encephalization levels are
second only to modern humans and greater than all other
mammals (Marino et al. 2004). Killer whales occur in all
oceans from Arctic to Antarctic ice, and from coastal waters
to open ocean (Wilson and Ruff 1999). They travel into bays,
channels, and estuaries. There are distinct markings among
geographic populations and in some parts of the Pacific, most
individuals are identified by markings and fin shape (Ford et
al.1994, 2000). The ongoing research has provided us insight
into the whales’ social behaviour, local movements, and diets
so that today the killer whale is one of the most studied of
marine mammals and sought after species by the watching
industry. Most of that research has been conducted in the
northeast Pacific where a few marine biologists have devoted
their careers to studying this species.
The killer whale is an abundant, highly social species with no
consistent geographical pattern of global diversity (Hoelzel
et al. 2002). However, cetacean
biologists divide the killer whales in the northeastern
Pacific into three forms – resident, transient and offshore
whales. ‘Offshore’ whales are not well known and there is
controversy among biologists about whether they should be
considered a unique group. About 300 of the ‘transients’ roam
from southeast Alaska to California. Residents are divided
into two genetically and morphologically distinct populations
in southern British Columbia and Washington, and the northern
residents in southeast Alaska (Bigg et al. 1987, Baird and
Stacey 1988, Bain 1989, Ford et al. 1998, Hoelzel et al. 1998,
Matkin et al. 1998). The southern residents are found mostly
in the southern Strait of Georgia, British Columbia, Juan de
Fuca Strait and Puget Sound, Washington and occasionally off
Vancouver Island, the Queen Charlottes Islands, and central
California (Ford et al. 1994, R. W. Baird pers. comm.). The
southern residents are reproductively isolated from northern
residents (Hoelzel et al. 1998). The northern residents amount
to about 200 whales in 16 pods (Ford et al. 1994, 2000). The
three pods that constitute the southern resident population
are known as J-pod, K-pod and L-pod. J-pod has 19 whales
K-pod has 16 whales, and L-pod has 47 whales that often break
into other smaller grouings (Heimlich – Boran 1988, Osborne
1999, Ford et al. 1994, Hoelzel 1992, Baird et al. 2004).
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