photo: Yohei Yamashita / flickr
The mammal with the largest brain is the sperm whale. An adult’s brain can reach around 8,000 cubic centimetres and weighs about eight kilograms. This compares with an average of approximately 1,300 cubic centimetres for a human brain. Although the head of the sperm whale comprises twenty-five to thirty-five per cent of its body length, the brain mass is only 0.02 per cent of its body mass.
photo: Gabriel Barathieu / flickr