Eschrichtius

The Gray Whale (Eschrichtius robustus) is a whale whichtravels between feeding and breeding grounds yearly. It reaches a length of about 15 meters, a weight of 36 tons and an age of50-60 years. Gray Whales were once called devil fish because of their fighting behavior when hunted. The Gray Whale isthe sole species in the genus Eschrichtius, which in turn isthe sole genus in the family Eschrichtiidae.

Population, distribution and migration

Two Pacific Ocean populations of Gray Whales exist: one smallpopulation travelling between the Sea of Okhotsk and southern Korea , and a larger one travelling between the waters off Alaska and the Baja California . A third, North Atlantic , population was hunted to extinction 300 years ago.

In the fall, the California Gray Whale starts a 2-3 month, 8 000 - 11 000 km tripsouth along the west coast of the United States and Mexico . The animals travel in small groups. The destinations of the whales are the coastalwaters of Baja California and the southern Sea of Cortez , where they breed and the young are born. The breeding behavior iscomplex and often involves three or more animals. The gestation period is about one year, and females have calves every otheryear. The calf is born head-first and measures about 4 metres in length at birth. It is believed that the shallow waters in thelagoons there protect the newborn from sharks . After several weeks, the return tripstarts. This roundtrip of 16,000 - 22,000km, at an average speed of 10km/h is believed to be the longest yearly migration of any mammal . A whale watching industry has sprung up along the coast.

Feeding

The whale feeds mainly on benthic crustaceans which it eats sideways from the sea floor. It is classified as a baleen whale and has a baleen, or whalebone, which acts like a sieve to capture amphipods taken in along with sand, water and other material. Mostly, the animal feeds inthe northern waters during the summer; during its migration trip, it mainly lives off its extensive fat reserves.

Physical description

Gray Whales are covered by characteristic gray-white patterns, scars left by parasites which dropped off in the cold feeding grounds.

Conservation and human interaction

The only predators of adult Gray Whales are humans and Killer Whales . After the California Gray Whales' breeding grounds were discoveredin 1857 , the animals were hunted to near extinction there. After harvesting becameinefficient because of dwindling numbers, the population recovered slowly, but with the advent of factory ships in the 20th century , the numbers declined again. Gray whales have been protected byinternational agreement since 1946 , and are not hunted anymore. As of 2001 , the population of California Gray Whales has grown back to about 26,000 animals.

The Atlantic population of Gray Whales was hunted to extinction in the seventeenth century.

Gray Whales in captivity

In 1972, a 3 month old Gray Whale named Gigi was captured for brief study, and then released off San Diego .

In January 1997, the new-born baby whale J.J. was found helpless near the coast of Los Angeles , 4.2 meters long and 800 kg heavy. Nursed back to health in SeaWorld San Diego, she was released into the Pacific Ocean on March 31, 1998, 9 meterslong and 8500 kg heavy. She shed her radio transmitter packs three days later.

In the news

Perhaps the most famous piece of Gray Whale lore dates from 1970 when, a long-dead,8-ton, 45-foot-long specimen beached itself south of Florence,Oregon . For a time it was a curiosity to local residents. As the beach is public right-of-way , it was the duty of the Oregon State Highway Division to dispose of it. They filled the animalwith a half-ton of dynamite , and the results could politely be called spectacular.On Thursday, November 12 , the dynamite was set off , and the blast did not go toward the Pacific as planned. No one was hurt, but a carwas crushed by falling blubber. Onlookers were covered with noxious-smelling bits of dead whale [1, 2].

1. On Oregon's exploding whale
2. Film of Oregon's exploding whale

External links

• Information on JJ from Sea World