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The sperm whale has the heaviest brain

Q: What animal holds the record for having the heaviest brain-- Walt B. Camarillo, California

A: The sperm whale has the heaviest brain: about 17.2 pounds (7.82 kilograms). Elephants do pretty well too: about 16.5 pounds for an African elephant. A human, on the average, has a measly 3.3-pound brain.

Right: [NOAA] Sperm whales frolicing

Species with the biggest brains also tend to be the ones with the biggest bodies. "...it might be that large animals just need larger brains to control and maintain their larger bodies," says Margaret Klinowska of Cambridge University, UK.

Here's the brain to body weight ratio for some species: sperm whale 0.02 %, cow 0.08 %, African elephant 0.15 %, human 2.1 %, sparrow 4 %, and Spider Monkey 5 %.

By the way, a sperm whale's tooth is the size of a big peanut-butter jar.

(Answered by April Holladay, science correspondent, August 22, 2001)

Further Surfing:

Phillip Colla: Underwater photos of sperm whales

Cambridge U: brains and behavior