Facts about blue whales
- The Blue Whale is the largest creature ever to have lived on earth.
- Their tongues alone can weigh as much as an elephant. Their hearts, as much as a car.
- Amazingly, however, this giant of the ocean feeds on some of the smallest marine life – tiny shrimplike animals called krill. A single adult blue whale can consume 3,6000kg of krill a day.
- They mainly catch their food by diving, and descend to depths of approximately 500m.
- The whale’s mouth has a fascinating row of plates fringed with bristles to help it filter its main source of food – plankton from the water. There is what looks like a moustache of long bristles on the end of each plate to help it hold the minute prey. With each mouthful, the whale can hold up to 5,000kg of water and plankton. Having forced the water out of its mouth, the whale licks these bristles with its fleshy tongue.
- Although the blue whale is a deep-water hunter, as a mammal, it must come to the surface of the sea to breathe. When it surfaces, it exhales air out of a blowhole in a cloud of pressurized vapour that rises vertically above the water for up to 9m.
- Blue whales occasionally swim in small groups but usually alone or in pairs. They are thought to form close attachments.
- In spite of their bulk, these graceful swimmers cruise the ocean at over 8km/h, and can reach speeds of over 30km/h.
- Though we can’t hear them, blue whales are one of the loudest animals on the planet, communicating with each other using a series of low frequency pulses, groans, and moans. It is thought that in good conditions blue whales can hear each over distances of up to 1,600km.
- Scientists think they use these vocalizations not only to communicate, but, along with their excellent hearing, to sonar-navigate the dark deep oceans.
- Females breed only once every three years and gestation is between 11-12months. Females usually only have one young.
- A baby blue whale (calf) emerges weighing up to 2,7000kg and up to 8m long. New born whales are helped to the surface of the water by their mothers and are often encouraged (nudged) by other females so that they can take their first breath of air.
- The calf is suckled in the water, drinking more than 600 litres of milk each day and gaining about 90kg every day for its first year.
- Blue whales have few predators but are known to fall victim to attacks by sharks and killer whales, and many are injured or die each year from impacts with large ships.
- It is thought that whales feel emotions.
- Intensive hunting in the 1900s by whalers seeking whale oil drove them to the brink of extinction. Hundreds of thousands of whales were killed. The 1966 International Whaling Commission finally gave them protection, although they have only recovered slightly since then. Blue whales are currently classified as endangered on the World Conservation Union (IUCN) Red List. It is estimated that only10,000-25,000 blue whales now swim the world's oceans.
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