Pacific Gray Whale

The Pacific Gray Whale, Eschrictuis robustus, is part of the group (suborder) of cetaceans known as baleen whales (mysticetes).  Baleen whales have no teeth, but instead use fringes of keratin (the same thing your fingernails are made of) to filter organisms from the water.  While most baleen whales filter the water for plankton or fish, Gray whales are unique in that they filter mud from the bottom!  A gray whale will suck up mud, then use its tongue to push the mud through its very coarse, rough baleen, capturing the organisms which have burrowed in the mud.

The Pacific Gray Whale is well known along the coast for its migratory behavior.  During the summer months, gray whales are found in the Bering Sea and Chukchi Sea in Northern Alaska.  In polar waters, sunlight around the clock during the summer months brings huge blooms of plankton and fish, thus providing a tremendous feeding ground for large numbers of whales.  In the fall, as sunlight diminishes and the temperature decreases, gray whales begin their southern migration.  Pregnant females lead the way down the western coast of North America, travelling in a predictable route that many whale-watching vessels and scientists take advantage of.  The destination for these animals and those that follow is the warm, shallow, protected lagoons of Baja, Mexico.  Giving birth in warm water is essential for gray whales, since calves are born without a layer of insulating blubber.  Newborn gray whales feed exclusively on milk produced by their mothers.  This milk, which has a very high fat content and is the consistency of cottage cheese, allows young gray whales to grow very rapidly and prepares them to make the long journey back to the summer feeding grounds by springtime.  This yearly 12,000 mile round trip makes the Gray whale migration the longest annual migration for any mammal. 

Gray Whale Quick Facts
Identification:  mottled gray color; encrusted with barnacles; lacks a dorsal fin-instead has dorsal ridge followed by 6-12 knobs; low, heart-shaped blow; raises its flukes upon diving

Length:  Maximum of 14.1 meters (46 feet); Females are slightly larger than males

Weight:  2-2.5 tons per meter, with a maximum of 35 tons (70,000 pounds)

Nickname:  Called “Devilfish” by whalers who often harpooned calves to keep their mothers in range

Current Status:  The North Eastern Pacific Gray whale stock is the only one of three stocks to survive commercial whaling.  The Gray Whale was protected by international and US laws to allow the population to recover.  The Gray Whale was recently taken off the Endangered Species List.

For more information on the California Gray Whale, please visit the American Cetacean Society web site at www.acsonline.org.