Blue Whale

Balaenoptera Musculus


The Blue Whale is found in the Indian Ocean and Southern Pacific Ocean. They can cruise at more than five miles an hour but when agitated they accelerate at up to twenty miles an hour. Blue whales swim individually or in small groups. Approximately 2,000 blue whales live off the California Coast and migrate to Mexico and Costa Rica.


The average Blue Whale is 70-90 feet long. A good way to visualize their length is to remember that they are about as long as three school buses. An average weight for an adult is 200,000 to 300,000 pounds. Its heart alone is as large as a small car. Blue whales are an overall blue-gray color. Blue whales are long and streamlined. Their dorsal fins are extremely small, and their pectoral flippers are long and thin. Blue whales are rorqual whales, a family of baleen whales with pleated throat grooves that expand when the animal takes in water while feeding.


The favorite food of these giants is krill, or shrimp-like euphausiids, that are up to three inches long. Blue whales must eat two to four tons of krill a day during the feeding season. During the winter months, they migrate to the warmer waters in Mexico and Costa Rica.


The blue whale was too swift and powerful for the 19th century whalers to hunt, but with the arrival of harpoon cannons, they became a much sought after species for their large amounts of blubber. The killing reached a peak in 1931 when 29,649 blue whales were taken. Today, there are between 8,000-9,000 blue whales in the oceans, and they are considered an endangered species. The 2,800 blue whales that feed along the California coast make up the largest concentration of blue whales in the world.


Females give birth to calves every two to three years. They remain pregnant for about one year before giving birth. When born, the blue whale calf is about 23 feet long and weighs 5,000 to 6,000 pounds. At six months of age the average length is over 52 feet. The blue whale reaches sexual maturity at around 10 years of age.


Blue Whales communicate through sounds that can travel across immense amounts of ocean. They communicate in this way in order to find food, navigate, and to find each other across long distances.

BY: Hope Warner