Gray Whale

Gray Whale, medium-size whale, occurring only in the North Pacific Ocean. Gray whales migrate between their winter calving lagoons off the coast of northern Mexico and their summer feeding areas in the northern Bering Sea—one of the longest migrations of any mammal. The range of gray whales once included the North Atlantic Ocean and the western Pacific Ocean between Japan and the Russian Kamchatka Peninsula, but they have since been hunted to extinction in the North Atlantic, and to near extinction in the western Pacific.

Gray whales may attain lengths of up to 15 m (up to 49 ft). They have a fleshy dorsal hump two-thirds of the way from the front of the body, but no true dorsal fin. The skin is mottled black, gray, and white, and this distinctive color pattern can be used to identify individuals. The whales are usually covered with barnacles and whale lice.

The diet of gray whales consists mainly of invertebrates that live in the muddy bottom of the Bering Sea. The whale sucks in mud along with the prey, then expels the muddy water by pushing its powerful tongue against short, bristly, yellow baleen plates that hang from the edges of the upper jaw and act as a sieve. Huge quantities of mud and food particles are expelled after a feeding dive, and seabirds often feed on these expelled food particles. Gray whales also suck in clouds of invertebrate prey from the water column, but they more commonly feed on the bottom.

Mature females may give birth once every two years. The mating season usually occurs during November or December. Gray whales appear to have a polygamous mating system. A single calf is born after a gestation period of 12 or 13 months and is nursed for seven or eight months. Males do not appear to play a role in caring for their young.

Gray whales swim more slowly than other whales and stay near shore in almost all parts of their range. This behavior made them easy prey for whalers who have hunted them relentlessly, nearly to the point of extinction in the 1800s and again in the early 1900s. The hunting of gray whales was forbidden by the International Whaling Commission (IWC) in 1947. As a result, gray whales in the eastern Pacific made a remarkable recovery to a total population of more than 20,000 animals by the 1990s. This dramatic recovery prompted the removal of the gray whale from the United States endangered species list in 1994. However, the population of whales in the western Pacific remains depleted, and the whale is still classified as an endangered species by the World Conservation Union (IUCN). The IWC permits the Siberian Inuits to harvest about 170 to 200 whales annually, and in 1997 voted to allow the Makah, a Native American group in Washington State that traditionally relied on whaling for subsistence, to hunt up to 5 whales each year. Gray whales are a favorite tourist attraction off the coasts of California, Oregon, and Washington states from November through April or May, when mothers and newly born calves can be seen as they migrate northward.

Scientific classification: The gray whale makes up the family Eschrichtiidae of the suborder Mysticeti, order Cetacea. It is classified as Eschrichtius robustus.

Contributed By:
Bernd G. Wursig

Gray Whale Microsoft® Encarta® Encyclopedia 2001. © 1993-2000 Microsoft Corporation. All rights reserved.