Image of Humbacked Whale under water

 

GRAY WHALE

Scientific Name: Eschrichtius robustus
Other Names: Scrag Whale, California Gray Whale, Devilfish, Mussel-Digger

This sizeable whale is best known for its far migration from its breeding grounds in Baja California to the feeding grounds in the Bering, Chukchi and the western part of the Beaufort seas. This involves travelling some 19 500 kilometres (or around 12 000 miles); the longest migration of any mammal in existence.


A young Gray Whale under water.


A model of a Gray Whale at Gray Whale, Monterey Bay Aquarium.

Physical Characteristics

The entire body of the Gray Whale is a mottled grey colour that can appear more slate-blue or whiter in appearance, depending on the individual. There are often white, yellow or orange blotches, but the extent of these varies from one animal to the next. The body is usually encrusted with barnacles, giving it a lumpy, almost dirty look.

The head is long and slender, arching between the tip of the snout and the blowhole, which is situated in a hollow. The mouth line is long, and can be straight or slightly arched.

Instead of a dorsal fin, the Gray Whale has a slight hump far down on its back. Behind this hump are six to 12 knuckles or bumps. The dorsal flippers are pointed and small, proportional to the body, and the flukes particularly large. In fact, these tail fins can reach widths of up to three metres (or almost 10 feet). The flukes have convex, often jagged, trailing edges.

Adult Gray Whales reach 12 to 14 metres in length, which equals about 39.5 to 46 feet. At full size, they weigh anything between 15 and 35 tonnes.

Behaviour
The Gray Whale is particularly active, and is often seen spyhopping, breaching and lobtailing. They love to ride in the surf and are, therefore, frequently found in shallow waters. Sometimes, they are spotted lying on their sides at the surface of the water and waving a pectoral flipper in the air.

The Gray Whale often travels alone, but is seen in pods of between three and 18 individuals too (depending very much on whether it is migrating, feeding or mating).

Where to Find Them
This whale species prefers shallow waters. In summer, it is found in the arctic waters, while winter sees them moving to the Mexican lagoons.

Diet
This baleen whale is, primarily, a bottom-feeder, getting small krill and, occasionally small fish, from the sandy ocean floor.

Threats
Whaling remains one of the largest threats to the Gray Whale. Although they are locally common, they are rarely seen in areas further abroad. Pollution and human development also endangers the wellbeing of these whales and conservation efforts being made to preserve the species. Fishing nets pose another massive threat to the Gray Whale. It becomes entangled in the nets and soon drowns when it cannot surface for air.