Gray Whale

Eschrichtiidae: Gray Whale Family

There is a single species in this family, which is in some ways intermediate between the rorqual and right whales, the other 2 baleen whale families. The gray whale differs from both of these in that it has two or sometimes four throat grooves instead of the 100 or more in the other baleen whales.

Gray whales undertake one of the longest migratory journeys of any creature on earth. Their size means that their only major predators are killer whales. These whales swim huge distances — up to 22,530 km (14,000 miles) - when migrating to and from their traditional breeding grounds. Gray whales spend their lives on the move. In autumn they swim from Arctic waters down the western coast of North America, mating on the way, to spend the winter in bays along the coast of Mexico. The young that were conceived during the previous year are born in these bays in late January and February, and soon after, the whales set off to spend the summer in the food-rich waters of the Arctic.

A similar migration takes place down the eastern coast of Asia, but these whales are relatively few in number. Gray whales spend a good deal of time playing in shallow water during the winter. They leap out of the water and may become stranded for a few hours as they wait for the tide to rise. While on the move they "spyhop", protruding their heads above the surface so that they can look around.

Gray whales do not have dorsal fins, but a series of small humps along their backs. They are often covered in white barnacles.

Gray whales are baleen whales that feed on the seabed. They drive their heads through the sediment to stir up prey. They then suck in the disturbed water and strain the animals from it. Most feeding takes place in the summer, and whales may fast for the remaining six months of the year.

The baleen itself, known as whalebone, used to be in great demand to make items such as corsets. Gray whale numbers have recovered significantly since protection of the species began in 1947.

Distribution: Occurs in the eastern North Pacific Ocean, in the Bering and Chukchi seas, migrating each October, travelling for two to three months to their breeding lagoons in Baja California.

Habitat: Shallow coastal water.

Weight: 3.6 - 8.2 tonnes (4 - 9 tons); females are slightly bigger.

Length: 7 - 9.8 m (23 - 32 ft).

Maturity: 5 - 11 years.

Gestation Period: 365 - 400 days.

Breeding: 1; weaning occurs after 7-8 months.

Diet: Filter-feeders, sucking up small amphipods and other crustaceans as well as worms, digging on the sea bed to obtain their food.

Lifespan: Over 80 years.

Status: Endangered.

Dorsal swelling

A prominent dorsal hump is present here, but no actual fin.

Barnacles

These are the white areas that develop on the skin.

Tail

The flukes have a diameter of up to 3.7 m (12 ft), and pointed tips.

Whale lice

Large congregations of these parasites create the yellowish-orange appearance.

FRIENDLY OR NOT?

Gray whales may allow themselves to be touched by whale-watchers in boats, but females will defend their calves determinedly.

The underlying gray colouration of these whales is not always obvious.