Orca (Killer) Whale

Hotspots:

Victoria, Campbell River, Telegraph Cove

History
Researchers from around the world have been coming to Vancouver Island to study the Orca (Killer) whales for a few decades making Orca whales here the best studied whales in the world. In the 1970’s Michael Bigg established a photo-identification technique that allowed researchers to identify individual Orca Whales. Soon researchers were able to put together pods and clan and estimate population sizes, social structure, birth and death rates, feeding habits and traveling patterns. There are three distinct groups of Orca Whales: Resident, Transients and Offshore Orcas.

Resident Orcas
Resident whales along Vancouver Island are split into two separate communities: Northern and Southern residents. There are just over 80 resident Orca whales that frequent the southern Vancouver Island region and Juan De Fuca Strait. These whales are quite used to boats and will often let the whale watching boats come quite close to them. Northern residents number around 260 and patrol the coastal areas from Campbell River up to Queen Charlotte Strait.

Residents in both the Northern and Southern Vancouver Island communities live in a matriarchal social order. Sons and daughters stay with the mother even after having their own offspring. Bonds between siblings can remain strong after the mother’s death and these families of whales are called matrilines. They travel together almost all the time except for possibly a few hours of foraging or mating. A pod consists of 1 to 4 matrilines that may be related and that travel together. Unlike matrilines, pods can separate for up to a few months at a time. A clan is a group of pods that have similar dialects and common but older maternal heritage. A community is defined as a set of clans that regularly mingle but do not necessaritly share vocal patterns.
The southern residents are one clan (J clan) that have 3 pods (J,K and L pods). The northern residents are 3 clans A, R and G totaling 34 matrilines and many pods in each clan. In the past 30 years or researching Orcas here, the northern and southern clans have not been seen in the same waters together.

Feeding
A resident Orca’s favorite meal is salmon (especially Chinook salmon) and they can hunt individually or in groups. Orca behavior can be quite different depending on which types of salmon are present. On the north and south eastern part of Vancouver Island the Chinook salmon are often close to shore and this is the Orcas favorite food. The Orcas will chase the Chinook salmon and on occasion the Chinook escapes in the kelp or rocky crevices. Instead of just finding a new salmon the whale may undulate his or her body making waves until the salmon comes out. The whales may take very deep dives for all types of salmon or swim near the tide rips picking salmon off as they come close. Orcas have been seen swimming through schools of pinks and coho to get the Chinook and will eat up to 150 kilograms (330 lbs) a day.

Socializing
Orcas are very social and can spend many hours intermingling with other maternal groups or other pods from different clans. In the Northern Resident Community one group may escort in another group which doesn’t frequent the area as much. Whales can get quite vocal when new groups are arriving and you may witness breaches, spy-hopping (where the head is completely out of the water), tail slaps and orcas rubbing bodies together.

Transient (Biggs) Orcas
Transient Orcas travel in smaller groups to effectively hunt smaller marine mammals, which are mostly seals, sea lions, dolphins, porpoises. On a rare occasion they will kill a calf from a larger Gray or Humpback whale. Transients to do not feed on salmon like residents do and therefore usually don’t echolocate when hunting prey since marine mammals can hear underwater. Their vocals can often be heard after a successful catch or when a catch is imminent. Transient Orcas have a similar matriline grouping to resident orcas however offspring may leave the mother at maturity.

Transients are not seen nearly as often as residents but will be mostly seen in Johnstone Strait, Queen Charlotte Strait and on the west coast of Vancouver Island near shore and number about 260. Their dorsal fin in more pointed and they generally take longer dives. Their frequency of vocalizing and their distinct call will help you distinguish these whales.

Offshore Orca Whales
Offshore Orca Whales spend most of their time along the continental shelf though they have been spotted up coastal inlets on occasion. Offshore Orcas have not received near as much study as the resident whales though scientists have made some guesses about their behavior. A 2011 study published in the journal of Aquatic Biology proves through DNA evidence that Offshore Orcas prey on large Pacific sleeper sharks. The shark’s skin is abrasive and therefore wears the whales teeth down considerable when compared to other resident and transient Orcas. Most encounters with Offshore Orcas are either more than 20 miles of the west coast of Vancouver Island or up near the Queen Charlotte Islands.

Orca Whale Taxonomy
Orca (Killer) whales are the largest mammal in the dolphin family. The largest male recorded was is 9.8 m (32 ft), weighing over 10 tonnes while the largest female is 8.5 m (28 ft), weighing 7.5 tonnes. Normally males range 7-9 meters (23 to 30 ft) long and weigh in excess of 6 tonnes and females normally range from 6 to 8 m (20 to 26 ft) and weigh from 3 to 4 tonnes. Males have noticeably larger pectoral fins than females and the dorsal fin is about twice the size. Orca Whales are the fastest marine mammal around Vancouver Island though its rare to witness the speed like we can with dolphins since dolphins follow cruising boats for short periods of time.

Orca whales can be identified from its pattern on the saddle patch as well as the dorsal fin. The saddle patch is a gray patch just behind the dorsal fin and is called a “saddle” since it looks like a riding saddle It is often unique to each whale. Other clues are the white eyepatch located just behind the eye, nicks and scratches and possible scars or tears on fins. Orca whales have great eyesight above and below the water though they don’t develop pigment cells called short-wave-sensitive (S-) cones, which are sensitive to blue light. Researchers conclude that whales can’t distinguish colors in the blue wavelength. They have a good sense of touch and and acute sense of hearing. It is known that whales can’t smell since they don’t have an olfactory bulb and there is not evidence they can taste. They have amazingly sophisticated echolocation skills being able to detect the location and characteristics of prey by emitting clicks and listening for echoes.

Life cycle and Reproduction
Males reach sexual maturity around 15 and start mating around 20 live about 30 years on average. The oldest known male was J1 estimated to be 59 years old when he died in 2010. Female killer whales begin to mature around 10 years reaching peak fertility around 20 years are usually are no longer fertile after 40. Females go through menopause and can live up to the age of 90. J2 (Granny), a resident orca who frequents southern Vancouver Island, is an estimated 104 years of age if she is still alive. This is a very rare case.
Gestation is usually 15-18 months. Mothers usually have a single calve about once every 5 years and births can happen anytime of year for resident pods though winter is more common. Calves are weaned around 12 months and is done by 2 years of age. Up to 50% of of calves die in the first 7 months. Researches have observed both male and female pod members helping in care of calves. Resident sons and daughters stay with the mother all their lives even after having their own offspring.