Whales - Species | Blue Whale

Blue Whale - Balaenoptera musculus

The Blue Whale is enormous and is named after the blue grey colour of its skin. It is the largest animal ever to be recorded on earth. They can grow to 100 feet long and weigh up to 150 tonnes, which is as heavy as a Boeing jet, plus their heart is the size of a small car. Their dorsal fins are extremely small, their pectoral flippers long and thin. A Blue Whale’s blowhole is capable of shooting water up to at least 30 feet when it surfaces for air. They take very short naps, often floating near the surface of the ocean with their thick layers of blubber keep them warm in cold waters. The species is known to produce tremendous sounds; possibly due to the fact that it is their way of sensing the geographical features of the ocean floor. Whales make sounds and listen to the pattern of returning echoes to help them find direction or objects. Another Blue whale fact: it has been speculated that this species may also make sounds to communicate with other whales and to find a mate.

The favourite food of these enormous creatures is krill. They feed on two to four tonnes of krill per day during their feeding season. Their feeding is concentrated during the polar summers, especially around the Channel Islands, Monterey Bay, and the Farallon Islands/Cordell Bank. During the winter months they migrate to the warmer waters in Mexico and Costa Rica. The Blue Whale feeds through a comb-like strainer of some 400 plates with bristles to capture the tiny morsels of food as the whale swims. In order to get enough to eat, a Blue Whale can expand its throat to take in as much as 50 tonnes of water in one gulp. It then forces the water out through comb-like plates which keep the krill in and letting the water filter out.

The reproduction of these large whales is slow. Females reproduce every two to three years and carry their young for a year before giving birth. Blue whales migrate from polar waters where they feed, to warmer, more temperate waters where they breed and give birth. A newborn calf is about 23 feet long and weighs two tonnes. A nursing Blue Whale mother produces over 50 gallons of milk per day. This milk contains 35 to 50% milk fat, so the calf rapidly gains weight at a rate of up to 250 pounds per day for the first year of its life. They are weaned from milk to krill at six months of age. They reach sexual maturity at around ten years of age.

The Blue Whale has been found in every ocean of the world, but there are only a few thousand that remain. For many years, they were aggressively hunted for their oil and blubber, dramatically reducing their original numbers. Between 1930 and 1931 almost 30,000 Blue Whales were hunted and killed. In 1966, the International Whaling Convention declared them a protected species throughout the world. Today, they are still considered an endangered whale species, with only a few thousand Blue Whales remaining in the world's oceans.