The skulls of gray whales differ from those of rorquals in that the telescoping of the bones that make up the dorsal surface is not as extreme. The baleen plates are short and narrow. A wide variety of invertebrates is taken, but crustaceans are the main source of nutrition for this species. Like rorquals, gray whales are migratory species. They summer at high latitudes in the Pacific, migrating during autumn to the west coast of Baja California and the south coast of Korea.
Pregnant females gather in shallow lagoons to give birth to calves.
Gray whales travel singly or in small groups of up to a dozen or so individuals. Populations of this species were nearly driven to extinction in the early part of this century. Protected from whaling, the eastern Pacific population has made a strong comeback. Walker's Mammals of the World, 4th edition . Savage, R. J. G. and M. R. Long.