|Size:||Length 80 to 85 feet (24 to 26 m)|
|Weight:||80,000 to 190,000 pounds (36287 to 86183 kg)|
|Diet:||Mostly krill, as well as other fish|
|Young:||1 calf every 2 to 3 years|
|Animal Predators:||Killer whale|
|Lifespan:||80 to 110 years|
· Blue whales were first discovered in 1692 by Robert Sibbald.
· The tongue of an adult blue whale can be as large as a mid-sized automobile.
· Long-term research on blue whales began in the 1980s.
Blue whales are not only the largest mammals in the world today, but in the history of the earth—not even dinosaurs were bigger than these whales. Their name comes from their blue-grey colour, although they were once called sulphur-bottom whales by sailors because of their yellowish bellies. The dorsal fin on blue whales is about one foot high. When blue whales blow water through their spout, the water goes as high as 25 to 30 feet (7.6 to 9 m) in the air. Rather than teeth, blue whales have baleen in their mouth, which are rows of bristly plates that resemble a comb. Baleen is made of keratin, the same flexible material found in fingernails and hooves.
Blue whales are found in all of the world’s oceans, including tropical waters and cold, polar waters.
The principle diet of blue whales is krill, a small, shrimp-like crustacean. An adult whale eats as much as four tons (3629 kg) of krill per day. They feed by opening their large mouths under the water and swimming through large schools of krill, other crustaceans or fish. Whales close their mouths around their prey, then they strain water out through the baleen, leaving behind only the food.
Blue whales are migratory animals, mating and giving birth in warm tropical waters during the winter, and moving north or south to cooler waters during the summer for periods of intense feeding. Female blue whales undergo an eleven-month pregnancy, giving birth to a single calf of about 23 feet (7 m) in length and weighing 5,000 pounds (2268 kg). Calves grow more than 200 pounds (91 kg) each day while nursing on their mothers’ rich milk (drinking about 100 gallons, or 379 litres, per day). Calves are weaned at seven to eight months of age, when they reach a length of approximately 50 feet (15 metres) and weigh about 50,000 pounds (22680 kg).
Despite their enormous size and due in part to their streamlined shape, blue whales are fast swimmers and range from a cruising speed of 22 km/hr to 48 km/hr when threatened. They usually feed at a depth of several hundred feet, but can dive deeper, holding their breath for up to 15 minutes if needed.
Prior to the mid-1860s, blue whales were not hunted because they were too large to catch and fast enough that whalers could not keep up to them. When technology made it possible to catch these whales, they were hunted nearly to extinction for their meat, oil and baleen. It is estimated that 360,000 blue whales were killed between 1900 and 1965 (30,000 in 1930 & 1931 alone). In 1965, less than 2,000 individuals remained. To fully protect them, the International Whaling Commission put a worldwide treaty into place, prohibiting hunting of blue whales. Within Canada’s 200-mile fishing zone, blue whales are also protected under The Canadian Whaling Regulations.
Blue Whale Wildlife Fact File, IM Pub, US