Killer whale
Orcinus orca

Up until 25 years ago, the killer whale was generally considered a bloodthirsty pest. Today, thanks in part to discoveries made in B.C., the killer whale is admired as a symbol of Canada’s wild and rugged west coast.

Description

The killer whale, or orca, is the largest member of the dolphin family. Its size, striking black and white colouring, and tall dorsal fin are unmistakable. Males reach lengths of 8 or 9 metres and weigh up to 5 tonnes. Females are smaller at 7 metres and 4 tonnes. Killer whales are mainly black above and white below, with an oval white patch behind each eye. In adult males, the paddle-shaped flippers are very large and the tips of the tail flukes curl down.

The first sight of a killer whale is usually its 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 every dorsal fin there is a gray area called a saddle patch. The shape of the dorsal fin and the saddle patch, as well as natural nicks and scars on them, are unique to each killer whale. By photographing the dorsal fin of killer whales, researchers can tell individual whales apart.

Range

Killer whales are found in all the world’s oceans, from polar to tropical seas. They seem to be most common in cold water regions, such as Iceland, Norway, Japan, Antarctica and the northeastern Pacific coast from Washington State to the Bering Sea.

British Columbia is one of the best places in the world to see wild killer whales. Many people are surprised to learn that there are two very different types, or races, of killer whale in B.C. They look very similar, but they act very differently.

Resident killer whales eat mainly fish. Their dorsal fins tend to be rounded at the top. They live in family groups of 5 to 50 whales, called pods. There are 19 pods of resident killer whales in B.C., adding up to about 300 animals. In the summer, residents are often seen in certain areas. The northern community of resident killer whales lives off northern Vancouver Island and the mainland coast as far north as southeast Alaska. Northern residents often visit Johnstone Strait off northeastern Vancouver Island. The southern community of residents is found off southern Vancouver Island. Haro Strait and the Strait of Juan de Fuca are good places to view them. Northern and southern residents are sometimes seen in winter, but can vanish for months at a time.

Transient killer whales eat marine mammals, such as seals, sea lions and porpoises. Their dorsal fins are more pointed. They usually travel in small groups of two to four animals who may or may not be related to each other. At least 218 transient killer whales are known to roam the coastal waters of B.C. and southeast Alaska. Transient killer whales are not predictable; they can be seen anywhere, anytime. Tran-sient and resident killer whales do not mix with each other.

What may be a third type of killer whale has been discovered in recent years. Researchers call them offshore killer whales, but since they have not been seen very often, very little is known about them. They are unlike residents and transients in a number of ways. There are slight physical differences, they usually travel in groups of 25 or more, they are seldom seen in protected coastal waters, and their vocalizations are unlike those of residents or transients. So far, most offshore killer whales have been seen near the Queen Charlotte Islands. But they can turn up anywhere. In 1992, a group of 65 offshores surprised researchers and whalewatchers near Victoria.

Behaviour

Killer whales are one of the most exciting whales to watch. Whether they are travelling, resting, hunting, beach rubbing, or playing with each other, there is always plenty to see.

B.C.’s resident killer whales are especially interesting because we know so much about them. In 1972, researchers began taking pictures of individual whales. From these photos, and by watching who travelled with whom, they learned that family life centres around females, and that a mother and her calves stay together for life. Even when they’re fully grown, sons and daughters never stray far from their mothers. Some killer whales, particularly females, can live as long as humans. Using all this information, researchers have put together family trees for all of B.C.’s resident killer whales. Family members within a pod are each identified by a letter and a number. This is very handy for researchers and whale-watchers. By identifying one whale in a group, they can often tell which family they are looking at.

Sound is very important to killer whales. Using air trapped in their blowholes, they produce high-pitched squeals, squawks and screams that often sound like a squeaky door hinge. Each family group of whales has its own set of unique sounds, or discrete calls, which together form its dialect. Some dialects are so distinctive that even an inexperienced listener can tell them apart. Researchers believe that the more similar the dialects between two pods, the closer they are related.

Killer whales also make clicking sounds which they bounce off objects in the water. This is a type of natural sonar called echo-location and is very useful when searching for food or navigating in murky water. Little is known about mating behaviour in wild killer whales. Females usually have their first calf at age 14 or 15 after a 17-month pregnancy — one of the longest of all whales. Newborn calves are 2.5 metres long and 200 kg, and drink their mother’s fat-rich milk for up to a year.

Status

Killer whales were once hated in B.C. They were considered ferocious and a nuisance. Fishermen complained that they were eating all the salmon, and often shot them on sight. In the late 1960s and early 1970s, a number of killer whales were caught alive in B.C. and Washington State waters for display in aquariums. Millions of people were able to see for themselves that killer whales did not match their fearsome reputation.

Today, wild killer whales are the star attraction of B.C.’s growing whalewatching industry. Every year, thousands of tourists take whalewatching trips into prime killer whale areas such as Johnstone Strait off northeastern Vancouver Island and Haro Strait near Victoria. Killer whales can also be seen from land anywhere along the coast. In 1994, six killer whales even came into the busy harbour of the city of Vancouver!

Just as we begin to understand the natural history of B.C.’s killer whales, they face new threats from human activity. Pollution, global overfishing, and increasing boat traffic are all ongoing concerns. Continuing long-term study will lead to a better understanding of B.C.’s killer whales and their habitat needs.