Category Zoology

Antarctic southern elephant seals are the biggest seals. Male seals grow up to six metres long, measure almost four metres around the middle and weigh in at about three tonnes.

Is it true? Sperm whales have the heaviest mammal brains.

Yes. A sperm whale’s brain weighs up to nine kilograms. That’s about six times heavier than a human brain! Luckily, the whale has a very large head to fit it in, which takes up about a third of its body.

Amazing! Most whales and dolphins are able to snooze for a few minutes while they’re swimming or resting on the sea floor. But it’s thought that the Dall’s porpoise never goes to sleep at all.

Which whale is the tiniest?

The smallest whale is probably the Commerson’s dolphin. This miniature mammal grows about one metre long. It would take about 3,000 dolphins to make up the weight of one blue whale.

Which whale has the tallest ‘blow’?

The ‘blow’ is the spout of water you see when a whale breathes out. The gigantic blue whale has the tallest blow. It can reach a height of twelve metres, as high as six tall people. Each whale makes a different pattern as it blows.

Harp seal pups are born with soft, white fur coats. They lose these after a month and grow dark coats like adult seals. In the past, thousands of pups were killed for their fur.

Amazing! Steller’s sea cows were huge dugongs that once lived in the Bering Sea. They were discovered in 1741. Just 30 years later, they were extinct because so many had been eaten by sailors.

Why are sea mammals in danger?

People are very dangerous for sea mammals. They hunt seals and whales for their meat, fur and blubber, and they trap sea mammals, such as dolphins, in fishing nets. Many more mammals are poisoned by pollution, such as oil from tankers, which is dumped into the sea.

Is it true? Right whales are easy to hunt.

Yes. Right whales were once the right whales to hunt. They swam slowly and floated on the surface when they were killed.

Which are the rarest sea mammals?

There are fewer than 600 Mediterranean monk seals left, but the rarest sea mammal is probably the Gulf porpoise. There may be only 50 left off the Californian coast.

When a baby blue whale is born, it weighs between two and three tonnes. It drinks about 200 litres of its mother’s milk a day, and by seven months old, it weighs 20 tonnes!

Amazing! Every year, a herd of about 1.5 million fur seals gather on the Pribilof Islands in Alaska to breed. What a squash!

Which sea mammals live in a pod?

Some dolphins live in family groups called pods. A pod may be hundreds of dolphins strong. The dolphins help each other out. If one of them is ill, for example, the others look after it, by pushing it to the surface so that it can breathe.

Which sea mammals live the longest?

Whales and dolphins have long lives. Fin whales probably live the longest, between 90 and 100 years. The Baird’s beaked whale is close behind. It can live for up to 80 years.

Is it true? Baby whales and dolphins are born head first.

No. A baby whale or dolphin is born tail first. Otherwise it might drown. Its mother pushes it to the surface so that it can take its first breath.

Picture Credit : Google

All of the great whales, such as the blue whale have hundreds of bony baleen, which they use to sieve food from the water. The Bowhead whale’s baleens are up to four metres long.

Is it true? Leopard seals are fussy eaters.

No. Leopard seals eat almost anything, including penguins, sea birds, fish, squid, seal pups, and even duck-billed platypuses!

How do leopard seals catch their prey?

Leopard seals mainly eat penguins. To catch them, the seals build up speed in the water, and then launch themselves on to the ice. They have even been known to snap at human divers, probably because they mistake them for penguins.

Which sea mammal has the biggest appetite?

Blue whales have massive appetites. In spring and summer, they eat up to four tonnes of krill (tiny, shrimp-like creatures) each day. That’s about five times as much food as you eat each year!

Amazing! Whales and dolphins can shut off their windpipes when they’re underwater. They do this when they’re feeding. It stops water from passing into their lungs and making them choke.

Dolphins are quick to learn tricks and remember instructions. This makes them very popular with people. They are also friendly and sociable. Many dolphins live in large groups. They play and hunt for food together.

Which seal has a huge nose?

The male northern elephant seal gets its name from its very long nose, which normally hangs down over its mouth. It can inflate its nose, like a balloon, to attract a mate.

Is it true? Beluga whales are called ‘sea canaries’ because of their yellow skin.

No. Beluga whales whistle and chirp just like singing birds, such as canaries. In fact, they make so much noise; they’re nicknamed ‘sea canaries’. Adult belugas have pure white skin.

Amazing! Blue whales’ voices are louder than the sound of a jet plane taking off, and can be heard over 500 kilometres away. As well as being the biggest animals, blue whales are the noisiest creatures in the world!

Why do whales sing to each other?

Whales build sounds into ‘songs’ which can last for ten minutes or more. The whales sing to keep in touch with each other, to find a mate and to frighten off rivals.

Picture Credit : Google

Humpback whales are very athletic. Even though the whales may weigh 65 tonnes, they can leap high into the air and come crashing down into the water on their backs. They can even turn somersaults in the air.

Amazing! In the Arctic and Antarctic, seals dive under the ice to search for food. They can hold their breath for up to 30 minutes before they need to come up for air, so they chew breathing holes in the ice with their strong front teeth.

Is it true? Whales slap their tails against the sea surface because they’re angry.

No. Some whales slap their huge tails down on the water but it’s not because they’re angry. This is called ‘lobtailing’ and it’s probably a signal to other whales.

Which sea mammals walk with their teeth?

A walrus’s tusks are actually its two upper teeth. They grow up to a metre long. The walrus uses its tusks to pull itself out of the sea and drag itself across the land.

Which sea mammals make the longest journey?

Grey whales spend the summers feeding in the Arctic. In winter, they swim to the coast of Mexico to breed. They swim back north again in the spring, a round trip of about 20,000 kilometres.