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Gray Whale (Eschrichtius robustus)

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Gray Whales in San Ignacio Lagoon

Gray whales in San Ignacio Lagoon, Baja, CA

marc uhlig, Flickr
The gray whale is a medium-sized baleen whale with a beautiful gray coloration that has white spots and patches. This species has been divided into two population stocks, one of which has recovered from the brink of extinction, and one that is nearly extinct.

Description:

The gray whale is about 45 feet long and weighs about 30-40 tons. They are a streamlined whale, with a tapered head and a throat that has 2-5 ventral grooves. Its gray skin has white patches, scratches, barnacles, and orange whale lice. Unlike many whales, the gray whale does not have a dorsal fin.

Classification:

Habitat and Distribution:

There once was 3 gray whale populations. The most familiar is the population in the eastern north Pacific - the whale commonly known as the California gray whale. These whales range from breeding/calving grounds off Baja California, Mexico, to feeding grounds in Northern California, the Gulf of Alaska, and the Bering and Chukchi Seas off Alaska. There is also a Western North Pacific (or Korean) gray whale stock found off the coast of eastern Asia, which is now very depleted, numbering only about 130 animals. The 3rd population is a North Atlantic population, which is now extinct.

'Flex,' a satellite-tagged western gray whale stirred interest from scientists when he traveled over 5,000 miles over 124 days in a trip from Russia to Oregon in fall-winter 2011. Photo-identification work revealed that Flex was also seen off Vancouver Island in Canada in 2008, and at that time, was thought to be a whale from the California gray whale population.

Feeding:

Gray whales feed in bottom sediments on small crustaceans such as amphipods. Gray whales filter these creatures from the sediments and water using its baleen plates, which hang from its upper jaw. Gray whales have about 300 baleen plates.

Reproduction:

Gray whales mate in warm waters in Baja California, Mexico. The gestation period is about 1 year, after which a calf 15-feet long and weighing about 1,100 pounds is born. Calves nurse for about 7 months.

Conservation:

The California gray whale is a success story in population recovery. With easy access to whales and their calves in the lagoons off Baja, gray whales were hunted nearly to extinction. After full protection from the International Whaling Commission in 1947, the population has rebounded to around 20,000 individuals. Western gray whales, however, still hover around the brink of extinction.

Sources:

  1. About.com
  2. Education
  3. Marine Life
  4. Marine Life Profiles
  5. Marine Chordates and Vertebrates
  6. Cetaceans - Whales
  7. Baleen Whale Information
  8. Gray Whale Profile - Facts About the Gray Whale

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