Family Balaenopteridae (Rorquals)

IDENTIFICATION
The Blue Whale is the largest creature ever to have lived on earth. The largest Blue Whale on record was a female from the Antarctic that measured 30 metres long and over 135 tonnes. Most North Pacific Blues reach a length of 25-26 metres. This large rorqual can be distinguished by its blue-grey colour. Only the undersides of its flippers are white. A small dorsal fin, approximately 30 cm tall, is located on the third of the back nearest the tail. The Blue Whale's tongue, palate and baleen plates are inky black. The blowholes are protected by large fleshy "splash guards" that expand and contract as the animal breathes. On the whale's underside, the throat grooves (found on all the rorquals) extend from near the tip of the jaw to past the navel.

MEALS, MANNERS AND MIGRATION
Mating season extends over about five months in the late fall and winter. Because seasons in the southern hemisphere run opposite to those in the northern hemisphere (i.e., when it's summer here, it's winter down under), Blue Whales in one hemisphere cannot breed with those in the other. Blue Whales reach sexual maturity at about ten years old, and females bear young every two to three years. After a gestation period of just over a year, a seven-metre long calf is born, weighing about 2500 kg. The mother supplies over 720 litres of milk a day, which is over 50 percent fat. The calf gains an average of 91 kg per day, and by eight months it weighs 22,680 kg. Adult Blue whales feed on krill, and devour six to eight tonnes of these euphausiids each day.

STATUS
Blue Whales seem to be growing in abundance in California waters, but few are seen off the coast of British Columbia; here, they are considered a rare species. COSEWIC lists the Blue Whale as vulnerable.

DISTRIBUTION
Blue Whales are found throughout the world's oceans, mainly along continental shelves and ice fronts, but also in shallow inshore regions and in the deep ocean. In B.C., the species was most frequently encountered by whalers off the west coast of the Queen Charlotte Islands and Vancouver Island. There have been recent sightings off Langara Island in the Queen Charlottes.