Gray Whale

Gray Whale

Mammalia

SCIENTIFIC CLASSIFICATION

COMMON NAME: gray whale, gray back, devil fish
KINGDOM: Animalia
PHYLUM: Chordata
CLASS: Mammalia
ORDER: Cetacea
SUBORDER: Mysticeti
FAMILY: Eschrichtiidae
GENUS SPECIES: Eschrichtius (named in honor of Danish zoologist Eschricht)robustus (robust, strong)

FAST FACTS

DESCRIPTION: This species of whale has short baleen, a proportionally small head when compared to other baleen whales, and no dorsal fin. Instead of a dorsal fin, they have 9-13 bumps or "knuckles" from the midpoint of the back to the tail flukes. They are, of course, grayish in color. Their throat grooves number from 2-4.
FEMALE As with other baleen whales, adult females tend to be slightly larger than the adult males.
SIZE: Newborn calves average 4.9 m (16-ft.)
MALE Male gray whales average 13 m (43 ft.)
FEMALE Female gray whales average 14.1 m (46 ft.). A maximum length for them is about 15 m(49 ft.)
WEIGHT: At birth, a gray whale is about 500 kg (1,100 lb.). The maximum weight for a gray whale is believed to be around 35,300 kg (78,000 lb.).
FEMALE Females may weigh almost 32,000 kg (70,000 lb.)
DIET: A gray whale's diet consists largely of sand crab-like crustaceans called amphipods
GESTATION: 13.5 months; mating season is from November to December and birthing season is from December to February; calving occurs about every two years
NURSING DURATION Females lactate for a seven-month period. By the end of this nursing period, the calf reaches a size of around 8 m (27 ft.) and 6,800 kg (15,000 lb.).
SEXUAL MATURITY: 6-9 years
MALE Males gain sexual maturity when they reach around 11 m (36 ft.)
FEMALE Females gain sexual maturity when they reach around 11.5 m (38 ft.)
LIFE SPAN: Approximately 40 years
RANGE: The Atlantic populations disappeared as larger scale commercial whaling began in the 17th century. California gray whales inhabit the eastern North Pacific Ocean. They spend summers in the icy waters of the Bering and Chukchi seas, off Alaska. As the ice pack advances in the fall, gray whales embark on one of the longest known migrations of any mammal. Hugging the North American coastline, the whales swim south more than 10,000 km (6,000 mi.) to Baja California, Mexico.
HABITAT: Gray whales mate and give birth in warmer water lagoons of Baja, California. Migration routes are along the North American coastline from the colder waters of the Bering Sea to the warm lagoons of Baja, California.
POPULATION: GLOBAL Atlantic population: extinct
Eastern Pacific population: approximately 24,000
Western Pacific population: 100-200 individuals
STATUS: IUCN Low Risk/Conservation Dependent
CITES Appendix I
USFWS Eastern Pacific population: Delisted taxon, recovered, being monitored
Western Pacific Population: Endangered

FUN FACTS

1. The gray whale is the only living member of the baleen whale family Eschrichtiidae. The gray whale differs from the other two baleen whale families primarily in its feeding behavior - it is a bottom feeder.
2. Gray whales are predominantly bottom feeders and forage along the ocean floor. Turning on its side, a gray whale gulps great mouthfuls of silt, strains out water and mud through its baleen, and swallows bottom-dwelling invertebrates. This whale species has the least amount of baleen-approximately 130 baleen strips on each side of jaw. The reduced number of baleen reflects the fact that they are bottom feeders.
3. Females give birth to 4.9 m (16 ft.) calves in the warm, shallow lagoons of Baja. While in the lagoons, some gray whales are unusually receptive to the attentions of human who travel to the lagoons to see them.
4. They are believed to be able to dive up to 120 m (395 ft.) and swim up to 15 kph (33 mph).
5. Gray whales are known to migrate more than 10,000 km (6,000 miles) each way-that's the longest known migration route of any mammal.
6. For more information about baleen whales, explore the BALEEN WHALES INFO BOOK.

ECOLOGY AND CONSERVATION

The eastern Pacific gray whale has made a remarkable recovery from times when they were heavily hunted. During the 19th and early 20th centuries, whalers hunted gray whales to the brink of extinction - twice. Legally protected since 1946, gray whales have made an astonishing comeback. The current population is about 24,000 individuals, a figure believed to match or exceed pre-whaling numbers. In 1994 the National Marine Fisheries Service (NMFS) removed the California gray whale from the Endangered Species List.

The eastern Pacific gray whale population was removed from the Endangered Species List in 1994 because it seems to have reached pre-whaling numbers (about 21,000 whales in 1993). The western Pacific stock is still at dangerously low numbers (perhaps 100 to 200 individuals) and the Atlantic stock is thought to be extinct.

Several key laws protect baleen whales, such as gray whales. The Convention in International Trade of Endangered Species (CITES) is an international treaty developed in 1973 to regulate trade in certain wildlife species. CITES protects all species of baleen whales.

In the United States, the Marine Mammal Protection Act protects all whale species, so it is illegal to hunt or harass them.

BIBLIOGRAPHY

Balcomb, Kenneth C., Larry Foster and Stanley Minasian. The World's Whales - The Complete Illustrated Guide. New York: Smithsonian Books, 1984.

Ellis, Richard. The Book of Whales. New York: Alfred A. Knopf, 1994.

Rugh, D.J., Muto, M.M., Moore, S.E. and D.P. DeMaster. Status Review of the eastern north Pacific stock of gray whales. US Dept. Commer., NOAA Tech. Memo. NMFS-AFSC-103. 1999.

Whales and Dolphins. Guide to the Biology and Behavior of Cetaceans. San Diego: Thunder Bay Press, 1998.