California
Eschrichtius robustus   1-Merrill Gosho, NOAA 2-Gerald and Buff Corsi, California Academy of Sciences | |
| Type of Animal: | Mammals |
|---|---|
| Class: | Mammalia |
| Order: | Cetacea |
| Family: | Eschrichtiidae |
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| State Status: | |
| Occurrence: | |
| Habitat: | Coasts |
| Description: | Gray whales are mysticetes, or baleen whales. Gray whales are the only species in the family Eschrichtiidae. They can grow to about 50 ft (15 m) long, and weigh approximately 80,000 lb (35,000 kg). Females are slightly larger than males. There are two major populations of gray whales: the western group occurs in the Far East near Korea. The group that we see along the California coast is the eastern group. Gray whales make one of the longest annual migrations of any mammal, traveling about 10,000 miles (16,000 km) round trip. The eastern Pacific stock of gray whales winters in Baja California and the southern Gulf of California. From late February to May, they migrate north along the coast, most of them continuing to the Bering Sea and Chukchi Sea. They migrate south beginning in late October, and most arrive in Baja California in December and January. Gray whales become sexually mature between 6-12 years, at an average of 8 years old. After 12-13 months of gestation, females give birth to a single calf. Newborn calves are approximately 14-16 ft (4.5-5 m) long, and weigh about 2,000 lb (920 kg). The average and maximum life span of gray whales is unknown, although one female was estimated at 75-80 years old after death (Jones and Swartz, 2002). Gray whales are bottom feeders, and suck sediment and amphipods (which look like tiny shrimp) from the sea floor. To do this, they roll on their sides and swim slowly along, filtering their food through coarse baleen plates, of which they have 130-180 on each side of the upper jaw. They often leave long trails of mud behind them, and oblong bowl-shaped "feeding pits" in the sea floor. Gray whales were once called "devil fish" because of their violent reactions when harpooned by whalers, or protecting their threatened calves. They were heavily hunted in the 1800s and early 1900s, and by the 1930s only a few hundred to a few thousand remained. The 1948 International Convention for the Regulation of Whaling banned all hunting of gray whales except by of for aboriginal people. The gray whale population has since risen to about 21,000. Besides humans, killer whales are the only known predator of gray whales. Currently, gray whales are known for their curiosity toward boats, and are the focus of whale watching and ecotourism along the southern portion of their migration. |
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| References: | Jameson et al. 1988. California Mammals. Wilson et al. (editors). 1999. The Smithsonian Book of North American Mammals. Whitaker (editor). 1998. National Audubon Society Field Guide to North American Mammals, Revised Edition. Jones, M.L. and Swartz, S.L. 2002. Gray Whale. Pp. 524-536. In: W.F. Perrin, B. Würsig, & H. Thewissen (eds.) Encyclopedia of Marine Mammals. |
| Other Sites: | Gray whale - Alaska Department of Fish & Game Gray whale - NOAA Fisheries |
| Field Office(s): | Arcata; Bakersfield |