NORTH PACIFIC RIGHT WHALE } Eubalaena japonica
FAMILY: Balaenidae

DESCRIPTION: Stocky, rotund whales with enormous heads, right whales are easily distinguished because they have no dorsal fin, a highly arched jaw, and many light-colored growths, called callosities, on their heads. Adults are generally between 40 and 60 feet long and can weigh 100 tons, making them one of the heaviest animals on the planet.

HABITAT: Right whales prefer coastlines and large bays but may also spend time in the open sea. They are very temperature sensitive, only inhabiting temperate waters between 20 and 60 degrees latitude.

RANGE: Historically, North Pacific right whales occupied a band of the Pacific Ocean that stretched from Japan across the Bering Strait and down the North American coast as far as California. Today, sightings are rare and generally occur in the mouth of the Sea of Okhotsk and in the eastern Bering Sea.

MIGRATION: Right whales summer in the southeastern Bering Sea; their winter habitat is unknown.

BREEDING: Right whales eight years and older mate between December and March, and after a yearlong gestation period, females give birth to a 2,000-pound calf. During mating, right whales nuzzle and caress one another, rolling about and exposing flippers, flukes, backs, and bellies. It is believed that right whales are polygamous and don't form permanent pair bonds. No aggression has been observed between competing males. Females breed only once every three to five years.

LIFE CYCLE: It is estimated that right whales live for at least 50 years.

FEEDING: Right whales are baleen whales, meaning they use a comb-like strainer made of hundreds of long, narrow baleen plates attached to their upper jaws to filter large amounts of plankton. They feed on or just below the ocean's surface, where there are large concentrations of food.

THREATS: The small size of the North Pacific right whale population, a result of past commercial whaling, makes this species extremely vulnerable. Oil and gas exploration and development, collisions with ships, entanglement in commercial fishing gear, industrial pollution, and global warming all pose threats to the survival of this great whale.

POPULATION TREND: The North Pacific right whale was subject to intensive commercial hunting, severely depleting the species by the late 1800s. As many as 40,000 North Pacific right whales were slaughtered during the 19th century. Once presumed extinct, there are likely fewer than 50 North Pacific right whales left today in the northeast Pacific Ocean and perhaps as many as 100 remaining in the northwest Pacific.

Photo of North Pacific right whale courtesy John Durban/USFWS