Sperm Whale about to dive.
The sperm whale is a pelagic mammal with a worldwide range, and will migrate seasonally for feeding and breeding.[3] Females and young males live together in groups while mature males live solitary lives outside of the mating season. The females cooperate to protect and nurse their young. Females give birth every four to twenty years, and care for the calves for more than a decade. A mature sperm whale has few natural predators, although calves and weakened adults are sometimes killed by pods of orcas.
Mature males average 16 metres (52 ft) in length but some may reach 20.5 metres (67 ft), with the head representing up to one-third of the animal's length. Plunging to 2,250 metres (7,382 ft), it is the second deepest diving mammal, following only the Cuvier's beaked whale. Original public domain image from Flickr