Killerwhale.org

British Columbia's Killer Whales: Residents, Transients and Offshores (Orcinus orca)
FACTS About Killer Whales
Common Name	killer whale		also known as orca
Scientific Name	Orcinus orca
Scientific Classification	Kingdom Animalia		all animals
Phylum	Chordata		have a developed notochord
Subphylum	Vertebrata		all animals with backbones
Class	Mammalia		warm-blooded animals that bear live young and have mammary glands
Order	Cetacea		all whales, dolphins, & porpoises
Suborder	Odontoceti		all toothed whales
Family	Delphinidae		all ocean dolphins
Genus	Orcinus
Species	orca
	Residents	Transients	Offshores
Population Status in Canada (cosewic)	Northern - Threatened Southern - Endangered	Threatened	Species of special concern
Dorsal Fin	Rounded tip usually with sharper angle at the rear corner	Fin tip is generally pointed	Continuously rounded over tip, usually lacks the sharper angle at the rear corner
Saddle Patch	Open saddle patch often seen	Saddle patch large and uniformly grey	Saddle patch either solid grey or open
Diet	Fish, especially salmon and squid	Marine mammals: seals, sea lions, porpoises, and small whales	Not certain: scientists believe they feed on schooling fish
Social Structure	Live in a matriarchal society. male and female offspring remain with their mother as long as she is alive	Social structure of transients is much looser than resident whales	Unknown
Sounds	Very vocal. - Whales that sound similar in their vocalizations are grouped together as clans	Very stealth hunters, echolocate very rarely, use passive listening to find their prey, tend to vocalize during or directly following a kill	A distinct call from transients and residents. frequently vocal, use lots of echolocation
Range	All along the western coast of North America from Southeast Alaska to California	All along the western coast of North America from Southeast Alaska to California	Far from coastline, encountered near Queen Charlottes, West Coast of Vancouver Island, seen as far south as Los Angeles
Typical Dive Times	3 – 5 minutes	7 – 10 minutes	Unknown
Length	adult female up to 7m
	adult male up to 9m
	newborn calf up to 2.5m
Weight	adult female up to 7,500 kg
	adult male up to 10,000 kg
	newborn calf up to 200 kg
Average Life Expectancy	female 50 years (can live up to 80 or 90 yrs)
	male 30 years (can live up to 50 or 60 yrs)
Travel Speeds	during a chase - 45 km/ hr for short bursts typical traveling speed - 6-8 km/h
Height of Dorsal Fin	adult female up to 1m
	adult male up to 2m

Photo by L. Barrett-Lennard and K. Heise

Killer whales are marine mammals and spend their lives in the sea. This makes it challenging for people to observe and study them in the wild.

Killer whales along the coast of British Columbia and Washington are among the best-studied whales in the world. Intensive field research in this region has been undertaken for almost 30 years. These studies have provided increased knowledge about these whales, yet they also illustrate how much remains to be learned.

RESIDENT KILLER WHALES

Resident killer whales eat fish, especially salmon, and squid. There has been no evidence so far to show that they prey upon any mammals or birds.
To locate their prey, they make noises that bounce back from nearby objects. This is called echolocation. With the help of sound, they can build a picture of their surroundings.
Resident pods are very vocal when they hunt for fish.
They hunt in large pods and may cooperate in catching prey.
Resident killer whales on the BC coast are divided into two groups, the NORTHERN community and the SOUTHERN community.
In the past it was thought that each community had a distinct range, however, as research continues it has been found that these ranges are not distinct and there is a lot of geographical overlap between the two communities. It should be noted that in the 30 years of research the two communities have not been found in the same area at the same time.
During the summer months, from June to September, the northern resident whales can generally be seen from northern Vancouver Island to Alaska. The southern resident whales generally inhabit the waters off southern Vancouver Island and down in to Puget Sound during the summer.

TRANSIENT KILLER WHALES

Transient in the waters of Alaska Photo by L. Barrett-Lennard
and K. Heise

Transients roam in smaller groups than resident whales.
The social structure is also much looser. The large kinship groups are usually formed because offspring often leave their mother and join other transient groups.

Transients are opportunistic eaters. They prey on marine mammals.
They do not vocalize as much as resident killer whales. Their prey have ears. If the transients were vocalizing much of the time their prey would also hear them and be alerted to the predators' approach.
A more successful hunting strategy used by transients is to be quiet and try to surprise their prey.

Transient attacking a sea lion
Photo by Jim Borrowman

Possibly for the same reason, vigorous displays, such as breaches and playing, are seen less frequently in transients than residents. Occasions when transients do show a lot of surface activity are during the act of killing their prey. Depending on the size of the animal being killed, it can be tossed around like a frisbee, thrown between individuals using powerful tail slaps, or forced underwater repeatedly until exhausted and drowned.

Transients can be seen all along the western coast of North America, from Glacier Bay in Alaska to the southern California coast. They tend to hug the coastline, checking out each cove for unsuspecting prey that will make their next meal. They are sometimes seen far from shore, although the extent of their range in the open ocean is unknown. Transients can be seen year-round, even though most reports are received in the summer. This is likely a viewer bias, as more boaters are on the water during the summer than in the winter.

OFFSHORE KILLER WHALES
It is thought that these killer whales feed on schooling fish, however nothing has been confirmed and the possibility that offshores also take marine mammals cannot be ruled out. These whales have a large proportion of nicks and scarring, relative to transient and resident killer whales, and one hypothesis is that sharks could be one of their diet items.	Offshore killer whales Photo by John Ford
They are frequently vocal and use a great deal of echolocation. Very little is known about offshore killer whales because they tend to spend most of their time far from the coastline. Most encounters have taken place near the Queen Charlotte Islands and 15 or more kilometres off the West Coast of Vancouver Island. They have been encountered as far south as Los Angeles.