Blue Whale

Blue whales are the largest animals to have ever lived on Earth — larger than any dinosaur. This is not common knowledge in its full implications: their hearts weigh 600kg, their calls travel 1,600km through the ocean, and a human could crawl through their aorta. Everything about them is at the edge of what biology can sustain.

Facts you didn't know

• 1

  Blue whales are the largest animals that have ever existed on Earth — larger than any dinosaur ever measured. The largest blue whales reach 30 meters and 200 tons. The largest known dinosaur (Argentinosaurus) may have reached 80 tons.

• 2

  A blue whale's heart weighs approximately 600kg — the size of a small car — and beats 8–10 times per minute at the surface and as few as 2 times per minute during a dive. A human could crawl through the aorta.

• 3

  Blue whale calls reach 188 decibels and can travel up to 1,600km through the ocean — the loudest sound produced by any animal, and one of the loudest biological sounds on Earth. They're below human hearing range but can be felt as pressure.

• 4

  Blue whales eat almost exclusively krill — tiny shrimp-like crustaceans averaging 2cm long. A blue whale consumes up to 4 tons of krill per day during feeding season, sieving them through baleen plates.

• 5

  Blue whales were hunted to near-extinction in the 20th century — populations dropped from an estimated 350,000 to approximately 1,000–3,000 by the 1960s. Current estimates suggest 10,000–25,000 remain, with populations slowly recovering since the 1986 whaling moratorium.