Blue whale is the largest animal on the planet. It can be found in all
oceans of the world. They usually spend the summer in arctic water and
migrate to southern (warmer) waters during winter time. Blue whales are
very old creatures - they exist on the Earth 54 million years. Number of
blue whales decreased drastically in the first half of the 20th century
when whalers hunted them nearly to extinction. Today, blue whales are
under protection and their number managed to increase a bit. When a blue whale exhales, the spray from its blowhole can reach nearly 30 ft (9m) into the air. Well, its time to have a glance at some of the facts you must know about these huge mammals.
- 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.
There are three main regions for the Blue Whale:
North Atlantic, North Pacific, and the southern hemisphere. Areas that
have distinct populations are the Sea of Cortez, Gulf of St. Lawrence,
Southern Ocean, Indian Ocean, and California.
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| A blue whale |
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| Comparison chart |
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