Killer Whale (Orcinus orca)
The Killer Whale is, apart from humans, the most widespread mammal in the world. Still, it is well known in only a few areas, and one of these is the coastal waters of British Columbia. In the early 1970s, researchers developed a system of photo identifying individual whales, in order to better understand their natural history and monitor the population. Every whale has identifying features on its dorsal fin, and the gray “saddle patch” behind the dorsal fin, and an extensive catalogue of Orca “mug shots” is now on file, each taken from the whale’s left side.
It was soon learned that these animals have a well-established family structure, travelling in groups called pods. Some of the pods lived in the northern part of the Strait of Georgia (the “northern resident” pods), and others remained in the southern half of the strait, and the Strait of Juan de Fuca (the “southern residents”). It was also discovered that there were other pods that seemed to move more randomly. They became known as the “transient” whales. While they looked similar, it was learned that they fed exclusively on marine mammals, while the resident whales appeared to feed only on fish, mainly salmon. A third group, which appears occasionally off the west coast, is still poorly understood. Each pod is structured around the oldest female, with males remaining in their mothers’ pods. These groups communicate vocally underwater, and each pod uses a slightly different dialect.
Because Killer Whales have been identified individually for some years now, their lives are becoming better known to marine biologists. The bulls are larger, reaching a weight of 9,000 kilograms, and a length of almost ten meters. A bull’s dorsal fin may be almost six feet high. Maturity may not be reached until the age of 15 to 20 years. Cows are thought to live longer than the bulls, with average life expectancy estimated to be 50 years. Some cows may be as old as 80 years of age.
With well-understood movements, the Killer Whale has become an extremely popular attraction for British Columbia visitors. Many companies offer whale watching cruises on Vancouver Island. As concern grows about the negative effects of whale watching, these companies are working very hard to self-monitor their activities. There is to date no evidence that the whales are suffering because of humans’ fascination with them.