There are two kinds of whale watching in British Columbia: Orca watching throughout the summer months and Gray whale watching in spring and fall.
Orca whales, also called Killer Whales, are actually the largest member of the dolphin family. Of the nearly 500 known orcas off the coast of British Columbia some 60% are members of resident pods and generally survive by following large schools of salmon and other fish. The other 200 or so orcas are known as transients and predate primarily on seals and other sea mammals.
Orca pods are organized along family lines with the eldest female orca dominating. Average pod size is from 5 to 20 individuals though pods of up to 45 orcas are not uncommon. A typical orca is just 2½ metres at birth and grows up to 8 metres for a mature cow, 10 metres for an adult bull. Cows live as long as 75 years while bulls are lucky to reach 50.
Except for a few year-round residents, Gray whales, are usually seen migrating past the British Columbia coast on their way to the Bearing Sea in the spring or back south to coastal Mexico in the fall. The biannual march of these cetaceans is the longest migration of any mammal on earth. Grays are suspected of navigating by using the globe's magnetic field as a compass.
Baja California is the midwinter scene of both mating and calving. Since cows will carry their offspring for a full year mating occurs every other year. Without a suitable source of food in Mexico they begin their 8000 km northward trek as soon as these rituals are completed, living exclusively off thick deposits of blubber in the meantime. Every March and April some 18,000 members of the Pacific herd pass Vancouver Island's western shores in small family groupings. Swimming slowly but steadily these monsters can cover a mere 60-80 km per day. Once they reach the Arctic Ocean and coast of Siberia the Grays gorge themselves on billions of tiny sandworms, sand fleas and other crustaceans which are sucked up from the sea floor in and filtered through the whales' baleen plates. Once the whales have replenished their reserves of blubber they begin yet again their southward swim, driven by the urgency of the calves growing within the pregnant cows. From early May onwards whale watching excursions switch focus to the resident Gray whales which feed on the beaches of Clayoquot Sound. Transient orcas, seals, sea lions and harbour porpoises and the odd minke or humpback whale are often sighted as well.
While the fall migration reaches its peak off the coast of Vancouver Island in December whale watching tours are usually popular from September through to the end of October. Heavy winter weather and short daylight hours preclude a longer season.