Sperm whales may team up and hunt collaboratively, scientists have suggested. A US research team used hi-tech tags to glimpse some of the giant marine mammals' remarkable hunting behaviour.

The underwater call of the sperm whale ... A whale's diet varies by species. Odontocetes, or whales with teeth, use echolocation to hunt their food with sound rather than sight.

Nantucketer Christopher Hussey kills the island's first sperm whale, and deep-ocean whaling commences. For the next century and a half, Nantucketers will specialize in hunting sperm whales.