25 Whale Facts: Gentle Giants of the Deep Ocean

Whales are mammals. They breathe air, are warm-blooded and feed their young milk.

Whales, dolphins and porpoises together form a group called cetaceans, with around 90 species.

Whales are divided into two groups: toothed whales, such as sperm whales and orcas, and baleen whales, such as blue whales and humpbacks.

Baleen whales have no teeth. Instead, they have long plates of baleen, made of keratin like our fingernails, which filter tiny food from the water.

Baleen whales have two blowholes, while toothed whales have just one.

A whale's spout is a cloud of warm breath and mist, and its shape can help experts identify the species from far away.

The closest living relative of whales is the hippopotamus.

Whales evolved from four-legged land mammals. One early ancestor, Pakicetus, lived around 50 million years ago in what is now Pakistan.

Some whales still have tiny hip bones hidden inside their bodies, left over from their land-dwelling ancestors.

Humpback whale songs spread like hit tunes

Male humpback whales sing long, complex songs made of moans, cries and whistles that can last for up to 20 minutes and be repeated for hours. All the males in a population sing the same song, but it slowly changes over time. Scientists have discovered that new songs can spread from one population to another across the ocean, almost like a catchy pop song going viral. Within a couple of years, whales across a whole region can switch to the new tune.

Humpback whales hunt together by blowing a ring of bubbles around a school of fish, trapping them in a "bubble net" before lunging up through the middle with mouths wide open.

Humpbacks make some of the longest migrations of any mammal, travelling thousands of kilometres between cold feeding grounds and warm breeding waters.

The blue whale is the largest animal known to have ever lived, reaching around 30 metres long.

A baby blue whale can drink hundreds of litres of milk a day and gain around 90 kilograms every single day.

Blue whales can eat several tonnes of tiny shrimp-like krill in a single day.

The sperm whale has the largest brain of any animal on Earth, weighing around 8 kilograms.

Sperm whales dive more than 2,000 metres deep to hunt squid, including the mysterious giant squid.

Sperm whales sleep upright in the water, floating vertically near the surface for short naps.

Ambergris, a rare waxy substance formed in the guts of some sperm whales, has been prized for centuries in making perfume.

Bowhead whales can live for more than 200 years

The bowhead whale of the Arctic may be the longest-living mammal on Earth. Scientists studying chemical changes in the eyes of bowheads estimated that some were more than 200 years old. Old stone harpoon tips from the 1800s have even been found buried in living bowheads. These whales have the thickest blubber of any animal, up to about 50 centimetres, and can smash through sea ice with their massive heads to make breathing holes.

A narwhal's long spiral tusk is actually a tooth that grows through its upper lip, and it can reach around 3 metres long.

The white beluga whale is nicknamed the "canary of the sea" because of its chirps, whistles and clicks.

Orcas, or killer whales, are actually the largest members of the dolphin family, and different orca groups have their own hunting styles and "dialects".

Whale poop helps fertilise the ocean, feeding tiny plankton that produce oxygen and absorb carbon dioxide.

Since a worldwide ban on commercial whaling began in 1986, some whale populations, such as many humpbacks, have made a strong recovery.