Size

Female gray whales reach lengths up to 45 feet and weigh as much as 70,000 lb. Males are slightly smaller. At birth calves are approximately 15 feet long.

Do they really have lice?

Gray whales, like some other baleen whales, are covered in whale lice and barnacles. The whale provides a substrate for them to live on and access to food. Whale lice feed on the whale's skin.

The lice are amphipods -- a kind of crustacean. (Other examples of crustaceans are shrimp and crabs.)

The barnacles attach to the skin with a super-glue like stuff they secrete from a "cement gland." Barnacles filter plankton from the water. Whether the barnacles bothers the whale or not is up for debate. Scientists don't believe the barnacles provide any benefits for the whale, but they probably don't hurt them either. (Speaking of barnacles, did you know beaked whales have them on their teeth?)

Where are they found?

Gray whales spend the summer in the Bering, Chukchi, and Beaufort Seas. Gray whales, like most other baleen whales, migrate to warmer waters during the winter months. The eastern Pacific stock of gray whales travels along the coast of the US and Mexico. During this annual migration, a gray whale can travel as far as 6,000 miles each way.
Pregnant females travel to the lagoons to give birth and raise the calf. The lagoons are protected from the open ocean, currents and predators. Others may travel to warmer waters or to find mates. Not all gray whales travel to the lagoons during the winter. Some may travel a portion of the way, some may not at all.

What do they eat?

Gray whales are benthic feeders. That means they search for food on the bottom of the ocean. They eat tiny shrimp-like animals like amphipods and other bottom-dwelling animals.
Gray whales are baleen whales. Baleen whales have plates of baleen that hang from the upper jaw. The baleen is used to filter food from the water.

How much do they eat?

Like other baleen whales, gray whales only eat part of the year. Gray whales eat when they're in the polar seas. An adult eats about 660 lb of food a day or 340,000 pounds during their 4 month feeding period.

Gray Whale Highlights

Gray whales were nearly hunted to extinction twice. Because they travel the same north-south routes on their migration and breed in the lagoons, they were easily found/hunted.

The first time the population almost became extinct was around the 1850s. That's when whalers found the breeding lagoons in Mexico. Then again at the turn of the 20th century. In 1946 international laws were passed to protect them.

The good news is, today the Pacific gray whale population is as large or larger than before people started hunting them. In other words, it is VERY healthy and strong.