Orca Whales
Killer Whales
The Killer Whales, are the ultimate predators in any ocean in the world and serve as ambassadors of one of the richest marine ecosystems on our planet However, the bio-diversity in the Pacific Northwest is astonishing and includes many other marine mammals: Minke whales, Gray whales, Humpback whales, Dall's porpoise, Harbor porpoise, California sea lions, Harbor seals, Elephant seals, Stellar sea lions, and one cannot forget the unbelievable range of marine birds.
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 35 years. These studies have provided increased knowledge about these whales, yet there still is much to be learned. Orcinus orca, better known as killer whales, are whales with teeth and are the largest member of the dolphin family. They are found in all of the world's oceans. Orcas are mainly black with white markings: on their bellies, behind their dorsal fins (saddle patches) and on the sides of their heads.
There are three genetically distinct groups of Orca that roam our oceans: Resident, Transient and Offshore.
Resident Killer Whales:
Resident Orcas travel in large family groups, or pods (sometimes exceeding 80 animals at one time). They are extremely vocal and their diet consists of approx. 32 different species of fish, primarily salmon. 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 underwater surroundings. (Orca sounds)
Resident killer whales on the BC coast are divided into two groups, the NORTHERN community and the SOUTHERN community.
The population of Orcas that reside in the waters surrounding southern Vancouver Island is made up of three pods; the J, K and L pods. These pods are commonly referred to as the Southern Residents. They frequent the Pacific Northwest area in the summer months, feasting on salmon populations that are running from the Pacific Ocean to the Fraser River to spawn (April-October). The Southern Residents have been researched for the last 35 years and each Orca has been photo-identified (picture ID, named, aged). The markings on their backs, which are behind the dorsal fin, are called saddle patches. These 'saddle patches' are essential like a human fingerprint, which allows for the approximately 87 Orcas to be individually identified. The three Southern Resident pods mate amongst each other and do not interbreed with the Northern Residents.
Transient Killer Whales:
Transient Orcas travel in small groups (approx 1-8 animals), vocalize infrequently and eat marine mammals, including seals, porpoise and other whales. Transients are opportunistic eaters. They do not vocalize as much as resident killer whales because their prey has ears. (Orca sounds)
A more successful hunting strategy used by transients is to be quiet (stealth-like) and try to surprise their prey.
Vigorous displays, such as breaches and playing, are seen less frequently in transients than residents, for fear of their prey being alerted to their impending approach. The 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 tennis ball, 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.
Offshore Killer Whales:
Offshore Orcas travel in very large groups, use frequent vocalizations and a great deal of echolocation (Orca sounds).
It is thought that these killer whales feed on schooling fish, however nothing has been confirmed and the possibility that off-shores also take marine mammals cannot be ruled out. Many details about offshore Orcas are still unknown, as they were only discovered in the early 90's. They tend to spend most of their time far from the coastline in very open and exposed waters.
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 an item on their menu.
Most encounters have taken place near the Queen Charlotte Islands and 15 or more kilometers off the West Coast of Vancouver Island. However, until just recently (2003 & 2004) we had a very large community of Off-shores on several occasions travel into the protected waters of the Pacific Northwest (120+ animals). This was a very unexpected pleasure, as many of us had never seen such a strong presence of this distinct group of Orca in our area before.
