Marine Mammals

What do you already know about mammals that live in water?

What would you like to find out about these sea creatures?

We can't wait to learn all about mammals?

Mammals that live in water are called marine mammals. Some spend their whole time living in water, such as whales and dolphins. However, some marine mammals such as seals and sea lions spend time in the water but can also survive on land. Even though lots of marine mammals spend their whole time in the sea none of them can breathe under water.

Mammals are vertebrates, which mean they are creatures with a backbone and a skeleton inside of their body. They are also are warm blooded, so they can usually keep their body temperature the same whatever the temperature is around it. They breathe air into their lungs, have some kind of hair on their body (sometimes just when they are born). A mammals brain is more developed than other types of creatures and some mammals have shown that they are very clever.

Mammals give birth to their live babies and look after them, feeding them milk and making sure they have the skills they need to survive. Mammals protect their babies until they are able to go off on their own.

Mammals that spend their whole time in the water include whales, dolphins, porpoises, manatees and dugongs. Then some marine mammals like to spend time in both the water and on the land. These mammals include seals, sea lions, sea otters, walruses and polar bears.

Can you believe it...

Some marine mammals, like some species of whales and dolphins, can sleep where one half of the brain goes to sleep while the other half stays awake.

Public Domain Image

Whales

As whales are mammals it means they are warm blooded and need lots of fat or blubber to keep them warm in the water. They can’t breathe under water so have to come up to the surface to breathe. They don’t breathe through a nose though; they have a blowhole on top of their heads and they breathe through that.

There are two different types of whales, toothed whales and baleen whales. Toothed whales have teeth and use these to catch their prey. Baleen whales don’t have teeth but instead have plates which have lots of hairs at the bottom, a bit like a thick comb or brush that they use to sieve the tiny little fish and krill they eat from the water. They take a bit mouthful of water with lots of tiny fish swimming in it, then push out the water from their mouth through the baleen to just leave the fish which they can then eat.

There are lots of different species or types of whales living in the oceans, but they are all either toothed or baleen whales.

Public Domain Image

Dolphins

Dolphins are a species of toothed whale.

Dolphins are thought to be incredibly intelligent. They live in big social groups called pods. They communicate with the dolphins in their pods in very clever ways. They can learn tricks, use tools and have been seen to show emotions.

Dolphins have a special way of locating prey and knowing what is around them using echolocation. They make sounds and when those sounds hit an object, they bounce back as echoes telling them where things are. Very clever!

Public Domain Image

Seals

Seals are mammals that spend most of their time in the water but also spend some time on land too. They have four flippers, which they use for swimming in the sea, and a small tail. They have fur and a thick layer of blubber to keep themselves warm in the water. Seals have a lot of blood in their bodies and blood carries oxygen, which means they can stay under water for about 2 hours, which is a long time for a mammal.

Seals like to eat fish and other small creatures they can find in the sea. They use their long whiskers to sense movement in the water to help them catch their prey.

Public Domain Image

Polar Bears

It might be a bit strange that polar bears are marine mammals, but it is because of how much time they spend in the water. Polar bears spend a lot of time in the water, sometimes swimming huge distances for days. They are incredibly good swimmers. They also find all their food in the water too, with their favourite creatures to eat being seals.

Polar Bears are one of the biggest species of bear. They have black skin and transparent hollow fur that looks white. They have a thick layer of blubber to keep them warm as well as their fur. Their huge paws act like snow shoes, helping them walk along in the snow.

Public Domain Image