to twenty years and care for the calves for more than a decade. A mature, healthy sperm whale has no natural predators, although calves and weakened adults are sometimes killed by pods of orcas.

Mature males average 16 m in length, with the head representing up to one-third of the animal's length. Plunging to 2250 m, it is the third deepest diving mammal, exceeded only by the southern elephant seal and Cuvier's beaked whale.