Killer whale
Scientific name: Orcinus orca
Taxonomy: Mammals
Status: Threatened, listed under SARA
Region: Pacific
Without a doubt, the killer whale is one of the most distinctive marine mammals in the world. Its size — seven to nine metres long and between four and five tones in weight — and its striking black-and-white colouring, and long, rounded body make it unmistakable. The first sight of a killer whale is often the tall dorsal fin. In fully grown males, this fin sticks straight up, often as high as 1.8 metres. In females and young whales, the fin is curved and less than one metre high. Behind the dorsal fin is a grey area called a saddle patch. The shape of the dorsal fin and saddle patch, as well as natural nicks and scars on them, are unique to each killer whale.
 The largest members of the dolphin family, killer whales are highly social animals that live in stable, family-related groups called pods. Led by females, these pods usually consist of five to 50 whales, although sometimes they can combine to form groups of 100 or more. Like humans, killer whales are very protective of their young.
Killer whales talk to each other through a complex variety of whistles, squeaks and whines made with air trapped in their blowholes. The sounds vary from pod to pod, with each group having its own unique dialect or language. Killer whales can recognize their own pods easily from several miles away based on the distinctive songs. Researchers believe that the more similar the dialects between two pods, the closer they are related. Pods of whales with related dialects are called clans. Killer whale pods are very vocal when hunting for prey. They use a series of clicking sounds that bounce off fish and other objects in the water. Called echo-location, this natural sonar is useful when searching for food or navigating in murky water, enabling the whales to build an accurate picture of what’s around them. With no natural predators, killer whales can live to between 50 and 80 years of age. That’s if they survive their infancy. Sadly, nearly half of all killer whales die between birth and the age of six months. This brings down this species’ average lifespan to 17 years for males and 29 years for females. Additionally, they calve only once every five years on average. All of these factors combined mean that killer whale populations tend to have extremely low growth rates. And that can make any threat to their survival a severe one.
The killer whale is a cosmopolitan creature, having been observed in oceans all over the world. They tend to concentrate in colder regions and are found in all of Canada’s oceans, as well as occasionally in Hudson Bay and in the Gulf of St. Lawrence. In British Columbia, they have been seen throughout almost all marine areas including many inlets and narrow channels. 
| Map: Tobi McIntyre |
Killer whales are not limited by such habitat considerations as depth, water temperature or salinity. They have been seen in water ranging from shallow (several metres deep) to open ocean depths. Resident killer whales live in separate northern and southern communities. The northern community lives off northern Vancouver Island and the mainland coast. Southern residents are found off southern Vancouver Island. The offshore population is small and is poorly studied. Some individuals have been sighted as far south as central California and as far north as Alaska.
Killer whales eat a wide range of prey, including squid, fish, sea turtles, sea birds, sea and river otters, sea lions, penguins, dolphins and other large cetaceans, such as the blue whale. Northern and Southern resident killer whales, however, eat mainly fish. The preferred prey of the offshore population of killer whales is not known, but is likely fishes. Transient killer whales eat mainly other marine mammals. However, because they tend to spend time in water less than five metres deep, often foraging in inter-tidal areas at high tide, transient whales have been known occasionally to eat animals such as deer, moose and pigs.
 Northern resident killer whales are potentially at risk from threats such as organochlorine and toxic-chemical contamination. Increasing levels of water pollution make the whales more susceptible to disease and reproductive difficulties. Sport and commercial fisheries have also depleted abundance of the various species of salmon on which the whales feed, leading to reduced food supply. As well, the closeness of the whales’ habitat to urban centers has led to more frequent collisions with boats and exposure to significantly higher numbers of oil spills. It’s also possible that the large and growing recreational whale-watching industry may be having a negative impact. Killer whales have no natural predators, but are vulnerable to mass strandings.
Recent studies have found that southern resident killer whales are contaminated with high levels of toxic chemicals such as organochlorine, making them susceptible to disease and reproductive difficulties. Water pollution also affects species on which the whales feed, leading to reduced food supply. The proximity of the whales’ habitat to large urban centers such as Seattle, Victoria and Vancouver has led to more frequent collisions with boats and exposure to significantly higher numbers of oil spills. The transient killer whale population is small—approximately 200 calves and adults—and its potential rate of increase low. Historic population numbers are not known, but are likely to have always been in the hundreds rather than thousands. Because many years often elapse between sightings of individual whales, it has been difficult to determine population trends with any degree of accuracy. Transient killer whales are potentially at risk from threats such as organochlorine and toxic-chemical contamination. Increasing levels of water pollution make the whales susceptible to disease and reproductive difficulties. High levels of water pollution also contaminate the whales’ prey. Recent studies have found that transient killer whales have the highest concentrations of organochlorines of any marine mammal. Increased ocean-going vessels might interfere with the whales’ echo-location method of hunting. It’s also possible that the large and growing recreational whale-watching industry may be having a negative impact. Among natural factors that threaten the survival of killer whales are mass strandings, in which large numbers of whales beach themselves at once and are unable to return to sea, and entrapment in narrow inlets or by ice. What’s being done
Legislation to protect killer whale populations in British Columbia waters was first introduced in 1970 under British Columbia’s Wildlife Act. In 1982, the whales were included in regulations under the Fisheries Act of Canada. These regulations prohibit hunting without a license, except for Aboriginal hunting. No licenses are currently being issued. Whale-watching guidelines have also been introduced to minimize negative interactions between boats and whales.
Fisheries and Oceans Canada is developing a recovery strategy for southern resident killer whales in the waters of the northeast pacific. Recovery planning is a two-part process. Part one is to develop a strategy that identifies recovery goals and broad approaches that address the immediate threats to the whales’ survival. Part two is to develop an action plan that outlines effective programs and strategies that will protect and recover the southern resident killer whale population. Development of a recovery strategy under SARA for transient killer whales is currently being considered. The strategy’s long-term objectives will include a better understanding of: - the impact of contaminants;
- the whales’ mating system to assess population viability; and
- diet and location of the whales at all times of the year.
What can you do?
Killer whales will get the protection they need only if all Canadians work together to reduce threats. Find out more about killer whales and be aware of man-made threats to northern resident killer whales such as entanglement in fishing gear, noise and water pollution, and collision with boats. Do your best to reduce these threats wherever possible to better protect the whales’ crucial habitat. Get involved with the Habitat Stewardship Program for Species at Risk (HSP) or another conservation organization. Join a stewardship program such as the B.C. Cetacean Sightings Network. The Network’s main goals are to identify key habitats and help reduce threats. The Network also solicits cetacean sighting reports from mariners along British Columbia’s coast. Find out more » Or, join the British Columbia Adopt a Killer Whale Adoption program, run in conjunction with the Vancouver Aquarium. Find out more »
Aquatic Species at Risk, Department of Fisheries and Oceans Canada
www.dfo-mpo.gc.ca/species-especes/home_e.asp Canadian Wildlife Service Species at Risk
http://www.speciesatrisk.gc.ca/search/speciesDetails_e.cfm?SpeciesID=699 Text:
Department of Fisheries and Oceans Canada with background information provided by Environment Canada in March 2004.
Revision: Tobi McIntyre, 2007 Photos:
Graeme Ellis
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