Whale

Giants of the ocean

Whales are part of the cetaceans group, along with dolphins and porpoises. There are over 80 species of cetaceans.

Class: Mammalia (mammal)
Order: Cetacea (Whales, dolphins and porpoises)
Suborders: Odontoceti (toothed whales) Mysticeti (baleen whales)

Whales are the giants of the sea. The sight of a great whale swimming in the ocean is unforgettable. Despite being huge animals, whales are not easy to spot because they glide silently along, creating hardly a ripple. They only give themselves away when they come up to breathe and send up gigantic spouts of air and water from their blowholes.

Whales are divided into 2 groups. The baleen or whalebone whales have no teeth, only a flexible horny substance called baleen suspended from the upper jaw, which acts as a sieve or strainer.

The baleen group of whales has 13 species, including most of the enormous whales. Toothed whales, dolphins and porpoises are a diverse group which is made up of more than 70 species and includes sperm whales and killer whales.

The largest mammal
They range in size from the compact minke whale, whose average length is around 8m, to the gargantuan blue whale, which can reach lengths of over 33m and weigh up to 120 tonnes - as much as 32 elephants! Toothed whales are smaller but vary in size, from 1.5m Hector’s dolphins to the 18m sperm whale that weighs almost 60 tonnes and is the world’s largest carnivore.

Life under water
Whales are mammals which returned to the sea about 50 million years ago and assumed a fish-like form. Their hind limbs disappeared and their front limbs evolved into flippers. Although they breathe air, whales cannot survive on land. Whales that accidentally get stranded on a beach soon die, because the great weight of their bodies crushes their internal organs.

While most whales are ocean-dwelling animals, some toothed whale species live in freshwater.

Whales move their body through the water with the help of their horizontal tail which flaps up and down. Whales can reach astounding speeds. Killer whales can reach 55 kph and some dolphins reach 35 kph. By contrast, humans’ top speed does not usually average above 8 kph.



Whales have a thick layer of fat called blubber under their smooth, almost hairless skin which helps them retain their body heat.

There she blows!
Whales can dive deeply and stay down a long time. The Sperm Whale, for instance, can dive down more than 2000m and remain below the surface for almost 2 hours! Like land mammals, whales have lungs and come to the surface of the water to breathe through their nostrils.

A whale's nostrils are called the ‘blowhole’, situated at the top of the head. A surfacing whale exhales warm air and moisture from its blowhole in a huge fountain. This was mistaken by old-time whalers for a spout of water. You can identify a whale species by the size and shape of its ‘blow’! Baleen whales have 2 blowholes whereas toothed whales have just 1.

What do whales eat?
Whales with baleens sieve out plankton, squid and small fish from seawater. Toothed whales prey on a variety of fish and squids. Whales swallow their food whole and have a muscular compartment to their stomach which crushes their food.

The song of the whale
Most whales are social animals and some travel in groups called pods. Whales communicate with each other by singing complex songs made up of a variety of whistles, clicks, low and high-pitched moans, grunts and groans. Some of these sounds are too high or too low-pitched for us to hear, but the noise travels long distances under water. In fact, whale songs are quite beautiful, even to human ears!

Raising young
A Baleen whale baby is born 11 months after mating. Some toothed whales have longer pregnancies. Whales only have one baby at a time and the baby is born tail first and is fully developed. Most whales nurse their young ones for about 6-7 months.

Conservation concern
Whales have been hunted for centuries for their blubber, oils, meat and baleen. Overhunting in the past has brought 7 of the 11 great whale species close to extinction. Even though most commercial whaling stopped 30 years ago, most of these species have not recovered to their original numbers.

The northern right whale shows no recovery at all and is the most endangered large whale with just 300-350 thought to be in existence.

WWF has made saving whales a top priority. It continues to argue against countries which want to resume hunting whales. WWF and other organizations were instrumental in getting the whole of the Southern Ocean and the Indian Ocean declared international whale sanctuaries.