Gray Whale

Gray Whale

Scientific Classification

Common Name
gray whale, gray back, devil fish
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Cetacea; more recently Cetartiodactyla
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 to 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:  13 m (43 ft.)
Female: 14.1 m (46 ft.). A maximum length for them is about 15 m (49 ft.)
Weight
Females may weigh almost 32,000 kg (70,000 lbs.) The maximum weight for a gray whale is believed to be around 35,300 kg (78,000 lbs.)
Newborn calves average 4.9 m (16 ft.). At birth, a gray whale is about 500 kg (1,100 lbs.).
Diet
Gray whales feed primarily on swarming mysids, tube-dwelling amphipods, and polychaete tube worms in the northern parts of their range, but are also known to take red crabs, baitfish, and other food (crab larvae, mobile amphipods, herring eggs and larvae, cephalopods, and megalops) opportunistically or off the main feeding grounds.

Gray whales suck sediment and food from the sea floor by rolling on their sides and swimming slowly along, filtering food through the 130 to 180 coarse baleen plates on each side of their upper jaw.
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 lbs.).
Sexual Maturity
Gray whales become sexually mature between 6 and 12 years with an average of 8 to 9 years old.
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
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.
 
The gray whale was once found in the North Atlantic. Sub-fossil remains, the most recent dated at around 1675, have been found on the eastern seaboard of North America from Florida to New Jersey and on the coasts of the English Channel and the North and Baltic seas. There are historical accounts of living gray whales from Iceland in the early 1600s and possibly off New England in the early 1700s.
 
The Atlantic populations disappeared as larger scale commercial whaling began in the 17th century.
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.
 
Gray whales are primarily bottom feeders and are thus restricted to shallow continental shelf waters for feeding. They are largely coastal although they do feed at greater distances from shore on the shallow shelf of the Bering and Chukchi seas.
Population
Atlantic population: Extinct
Eastern Pacific population: The most recent estimate is 15,000 to 22,000 for 2001-02. The population appears to be stable.
Western Pacific population: The western Pacific subpopulation remains at a small fraction of past levels and is estimated to number about 100 individuals, of which 20 to 30 are mature females.
Genetic studies and differential recovery patterns suggest that the small western North Pacific subpopulation is isolated from the larger eastern subpopulation.
Status 
IUCN: Least concern; the western subpopulation is listed separately as Critically Endangered
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 earned the nickname "devil fish" because of their aggressive reactions when harpooned.
  3. 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.
  4. 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 presence of humans.
  5. They are believed to be able to dive up to 120 m (395 ft.) and swim up to 15 kph (33 mph).
  6. 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.
  7. For more information about baleen whales, explore the Baleen Whales InfoBook.

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. Gray whales have been protected from commercial whaling by the International Whaling Commission (IWC) since its establishment in 1946.

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. Commerce., NOAA Tech. Memo. NMFS-AFSC-103. 1999.

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

Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008. Eschrichtius robustus. The IUCN Red List of Threatened Species 2008: e.T8097A12885255. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T8097A12885255.en/. Downloaded on 28 September 2018.

NOAA Fisheries – Gray Whale Species Profile. https://www.fisheries.noaa.gov/species/gray-whale/. Downloaded on 28 September 2018.