Rorquals: Balaenopteridae

Physical characteristics: The blue whale is the largest animal on the planet. Their skin is gray or blue-gray with lighter colored splotches. Blue whales grow to between 74 and 79 feet (23 and 24 meters) and weigh up to 200 tons (181 metric tons). Females are slightly larger than males.

Geographic range: Blue whales are found in all oceans worldwide.

Habitat: Blue whales spend the spring months in the colder waters close to the poles, but migrate toward the warmer regions closer to the equator for the other eight months.

Diet: Blue whales eat only during the spring for about four months when they feed in colder waters. The rest of the year, they live off stores of blubber, fat, that they build up during the feeding season. Blue whales eat krill and generally avoid other marine life. When they are feeding, they can eat 8 tons (7.3 metric tons) of krill per day.

Behavior and reproduction: Although they usually swim at about 14 miles per hour (22 kilometers per hour), blue whales have been

Blue whales are the largest mammals on Earth, and can live over one hundred years. (Phillip Colla/Bruce Coleman Inc. Reproduced by permission.)

known to swim as fast as 30 miles per hour (48 kilometers per hour). They dive for ten to twenty minutes to feed and generally do not dive more than 300 feet (91 meters) below the surface. Female blue whales give birth in late spring and summer after twelve months of pregnancy to young that are about 23 feet (7 meters) long. Blue whales can live past one hundred years of age.

Blue whales and people: When whalers began using ships that allowed them to haul up whales no matter how large they were, the blue whale populations dropped dramatically. Because of their size, blue whales were highly prized, as whalers could bring in large amounts of oil, blubber, and meat with a single kill. During the years of 1930 and 1931, almost 30,000 blue whales were killed. During the 1960s, the blue whale gained protection from the International Whaling Commission. The blue whale may not survive much longer. Some scientists predict that the remaining population of about five hundred whales is not large enough to support a recovery. In recent decades the blue whale has taken a place in popular culture, and its image has helped to promote conservation efforts and ecotourism activities such as whale watching.

Conservation status: Blue whales are Endangered. ∎