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Are whales mammals or fish?

Whales, dolphins and porpoises, are all mammals - just like us!

All mammals share five characteristics:


Mammals breathe air.

Just like humans, whales and dolphins breathe oxygen out of the atmosphere. This means that they have nostrils (we call them blowholes) which connect to a pair of lungs. Whales and dolphins MUST come up to the surface to breathe!

Hair or fur

Mammals have hair or fur.

You may not think of whales and dolphins as fuzzy creatures, but they all have hair at some point in their lives. Some whales, such as humpback whales and right whales, have short hairs on their faces that remain throughout their lives. For many species, they have hair when they are in the womb or just born, but shed that hair shortly after birth.

Give birth to live young

Mammals give birth to live young.

While some animals reproduce by laying eggs, all whales and dolphins reproduce through pregnancies where they young develop inside the mother's body.

milk bottle

Mammals produce milk and feed this milk to their young.

When whales and dolphins are born, they are fed milk that is produced by their mother's mammary glands. Whales and dolphins have slits on their underside that contain their mammary glands. Because they have to nurse underwater, the milk produced by whales and dolphins has a higher fat content which helps it stay together in the water.


Mammals are warm-blooded.

Just like humans, whales and dolphins can maintain their body temperature regardless of their environment. The opposite is cold-blooded, which means that the body temperature of these animals depends on the temperature of their environment.

Amazing facts about whales and dolphins

Dive deeper into the world of whales and dolphins and learn more about their lives.

A humpback whale pokes its head partway out of the water, a behavior called spyhopping

Facts about whales

Amazing facts about whales, the largest mammals to live on Earth.

two dolphins diving down out of the water

Facts about dolphins

From the orca to the tiny vaquita, learn more about these creatures.

Northern Resident orca, Fife, swimming at the surface

Record breakers

Whales and dolphins hold some incredible records.

Breaching North Atlantic right whale

Brain power

Just how intelligent are whales and dolphins?

Make a difference

Join our team  - no matter which way you choose, your commitment helps whales, dolphins, and our shared planet.

Save the whales, save the world.

Humpback whale spyhop


Adopt a whale and help us protect these amazing creatures.

Bottlenose dolphin calf breaching with its whole body out of the water


You can join our team and help us save whales and dolphins

Breaching North Atlantic right whale


Your gifts help us take action for whales and dolphins.

Orca spyhop


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