11 Facts About Blue Whales, the Largest Animals Ever Known to Live on Earth

Written by Melissa Breyer

So colossal are these majestic marine mammals, their hearts alone weigh as much as a car.

Picture in your mind a 10-story-tall animal walking down the street and you probably start channeling images of Godzilla or King Kong. But if you imagine it as a marine mammal and place it on its side, swimming … now you’ve got a blue whale.

Balaenoptera musculus, the blue whale, is the largest animal ever known to have lived on the planet – movie monsters aside. Even at birth it is one of the world’s biggest animals! The planet is covered with amazing, fascinating creatures, but the blue whale ranks among one of the most superlative. Consider the following.

1. They’re ginormous

They’re gigantic, they’re enormous, they’re ginormous! Generally ranging in length from 80 to 100 feet (24 to 30 meters), the longest one ever recorded was a magnificent 108 feet long.

blue whale size

Photo Credit: Ocean Institute

2. They’ve got mass

Blue whales weigh up to 200 tonnes, or around 441,000 pounds.

3. They’ve got big thumpers

The blue whale’s heart is huuuuge! As in, the size of a car; its beat can be detected from two miles away.

4. And tongues

A blue whale’s tongue alone weighs as much as an elephant.

5. They’re big babies

Not as in sissies, but as in born big. The biggest babies on earth, easily, and at birth already rank amongst the largest full-grown animals. They pop out at around 8,800 pounds with a length of some 26 feet. They gain 200 pounds a day! Their growth rate is likely one of the fastest in the animal world, with a several billion-fold increase in tissue in the 18 months from conception to weaning.

6. They’re loud … and make long-distance calls for free

Blue whales, in fact, are the loudest animals on the planet. A jet engine registers at 140 decibels, the call of a blue whale reaches 188. Their language of pulses, groans, and moans can be heard by others up to 1,000 miles (1,600 kilometers) away.

7. They’ve got big appetites for tiny fish

Blue whales feast on krill; their stomachs can hold 2,200 pounds of the tiny crustaceans at a time. They require almost 9,000 pounds of the little guys a day; and around 40 million krill daily during the summer feeding season.

8. They can scoot

They travel a lot, spending summers feeding in polar regions and making the long trip to the Equator as winter comes along. While they have a cruising speed of 5 MPH, they can accelerate up to 20 MPH when needed.

blue whale aerial

Photo Credit: NOAA Photo Library

9. They’ve got long lives

While not nearly as old as the Earth’s oldest trees, blue whales are among the planet’s longest-lived animals. Kind of like counting tree rings, scientists count layers of wax in the ears and can determine a ballpark age. The oldest they’ve discovered this way was calculated to be around 100 years old, though the average life is thought to be around 80 to 90 years.

10. They were once numerous

Before whalers discovered the treasure trove of oil that a blue whale could provide, the numbers were generous. But with the advent of 20th century whaling fleets, nearly every last one of them was killed before receiving worldwide protection in 1967. According to WWF, from 1904 to 1967, more than 350,000 were killed in the Southern Hemisphere. In 1931, during the heyday of whaling, an astounding 29,000 blue whales were killed in a single season.

11. Their future is unclear

While commercial whaling is no longer a threat, recovery has been slow and new threats plague blue whales, like ship strikes and the impact of climate change. There is one population of around 2,000 blue whales off the coast of California – but all told there are only around 10,000 to 25,000 individuals left. The World Conservation Union (IUCN) Red List rates them as Endangered. Hopefully with time, the planet’s giantest gentle giants will again roam the seas aplenty.

Sources: WWFNatoinal Geographic

This post originally appeared on TreeHugger.

Photo Credit: flickker photos/Flickr


Julia Oleynik
Julia Oleynik6 months ago

Thank you for sharing

Sarah Hill
Sarah Hill11 months ago


Marie W
Marie W11 months ago

Thank you for sharing.

Simon L
Simon Labout a year ago


Chun Lai T
Chun Lai Tabout a year ago


Chun Lai T
Chun Lai Tabout a year ago


Greta H
Past Member about a year ago

Incredible animals. Thank you.

George L
George Labout a year ago

Thanks for sharing.

Deborah J
Deborah Jabout a year ago

Good to know. And we don't have to keep them in pens and doing tricks for people to learn about them and appreciate them.

Siyus C
Siyus Copetallusabout a year ago

Thank you for sharing.