The Gray whale, scientifically known as Eschrichtius robustus, is a baleen whale migrating between feeding and breeding ground yearly. It is the only living species of its genus. Eschrichtius in turn is the only genus of the family Eschrichtiidae. This whale is descendant of filter-feeding whales, which developed 30 million years ago. The gray whale is distributed in an eastern North Pacific population and a critically endangered western North Pacific population. North Atlantic populations were extirpated on the European coast before 500 AD and on the American coast around the late 17th to early 18th centuries.
The whales have mottled grey skin with scarring and pigmentation and much of the body is covered with barnacles and whale lice. Average adult ranges from 11 – 14 meters in length. This whale possesses no dorsal fin, only a small hump followed by a series of ‘knuckles’, which covers 2/3 of the way back from the head. The blow is a typical characteristic of all the whales. In its case the blow is low and bushy, up to 3-4 meters in height, and often ‘heart’ shaped. It is the only baleen whale in which the upper jaw is longer than the lower jaw. The baleen plates are short about 5-25 cm, uniform and cream-yellow in color.
The Gray whales are very unobtrusive at the surface; so sometimes referred to as ‘breathing rocks”. They do not breach. Socially the whales are normally solitary, and pairs of mothers and calves are often seen during migration. A migrating gray whale has a predictable breathing pattern, generally blowing 3-5 times in 15-30 second intervals before raising its fluke and submerging for 3-5 minutes. A gray whale can travel at 3-6 miles per hour. At one time there were three different gray whale populations: a north Atlantic population, a Korean or western north Pacific stock and the eastern north Pacific population, the largest surviving population.