Gray whale

Gray whales (Eschrichtius robustus) were known by whalers as "devilfish" because they defended themselves and their calves so fiercely.

They are mottled gray in colour with a narrow V-shaped head. Whale lice and parasitic barnacles create light coloured patches on their bodies. Instead of a dorsal fin, gray whales have nine to 13 bumps along their dorsal ridges.

They grow to between 12.2 and 15.2m. Gray whales produce a range of sounds including moans, rumbles and growls. The most prevalent call is a series of knocking sounds.

Where are they found?
The eastern North Pacific stock of gray whales prefer shallow, coastal waters and feed over the oceanic continental shelves of the Bering and Chukchi seas between Alaska and Russia during the summer. In the winter, many migrate along the west coast of the US, Canada, and Mexico.

What do they eat?
Gray whales, like other baleen whales, strain their food from the water through baleen plates. However, they are different from other shallow feeding great whales in that they prefer prey that lives near or on the sea floor.

How long do they live?
Gray whales mate at around eight-years-old. Females are pregnant for about 13 months every two to four years. Calves can swim as soon as they are born and can double their weight in about three months, and double their length in about two years. A mother and calf form a very close attachment, with the calf spending the majority of its time swimming close to its mother.
It's difficult to tell how old gray whales are because they have no teeth (which can be used to estimate age in other mammals). They do die of natural causes but sometimes fall prey to killer whales.

Gray whales and hunting
From the 17th to early 20th centuries, humans hunted gray whales commercially for oil, meat, and clothing such as corset stays, umbrella ribs and buggy whips. Today, some indigenous people practice controlled subsistence whaling on a small scale.

Conservation concerns
There was once a third population of gray whales in the North Atlantic but this was hunted to extinction. Like other large whales, gray whales are now threatened by environmental change, including habitat loss and toxics, and are also harmed by ship strikes and entanglement in fishing gear.

The eastern North Pacific population of gray whales, numbering more than 17,000 whales, was removed from the United States Endangered Species List in 1994. However, the western North Pacific population is so severely depleted that it is now listed as Critically Endangered. It is threatened by intensive oil and gas development in its feeding grounds in particular.