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California Gray Whales

Some answers to questions we've been asked about these magnificent creatures.

What are Gray whales?
California Gray Whales are baleen whales, meaning that they strain their food from the surrounding water and mud using plates or baleen. Many biologists believe that Gray Whales were among the first whale species to evolve.

How big are Gray Whales?
Gray whales are among the largest whales. Adults are about 35-45 feet long and weigh 22-35 tons. Females are larger than males.

How many species of Gray Whale exist?
Today there is only one species (Eschrictius robustus) that is found in the Pacific. However, there was an Atlantic Gray Whale that was driven extinct, probably from hunting.

Are Gray whales only found off the US west coast?
No there is another population found off the coast of Japan and Korea. This population is in serious trouble. Its numbers probably exceeded 5000 but today there are only about 500 left. Indeed in 1982 it was declared "virtually extinct"

Where do California Gray Whales live?
California Gray Whales divide their year between summer in Alaska and winter months in the lagoons of Baja California Mexico. In the cold and productive waters of the Bering Sea they feed on small crustaceans (e.g. mysids and ghost shrimp) that they suction up from the mud. Around October they head southwards through Unimak passage, and arrive in the Baja lagoons around late December. 1998 was an unusual year that had many biologist worried. Gray whales were late leaving their feeding grounds in Alaska. Many scientists wonder if they and their ecosystem are in trouble.

What happens once they arrive in Baja?
The lagoons are the birthing grounds of the California Gray Whale. All whales were born here. Pregnant females give birth, and non-pregnant adult females mate. It seems that whales don't feed in the lagoons making it all the more remarkable that the undertake an 8000 mile journey without food.

How big are the calves when they are born?
Calves are on average 12-16 feet and weigh around 1500-2000 lbs. Big babies!! They feed on their mothers milk for the first six to eight months of life.

When do Gray Whales return to Alaska?
The first whales start to leave the lagoons around March., Males leave first and mothers with young calves are the last to leave. Travelling northward, they hug the coast of California, Oregon and Washington.

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If you are interested in getting involved in this project and want to assist volunteer opportunities are available, please contact Dr. Brosnan at SEI 503-246-5008