As a result of the apparent rarity and open-ocean habitat of Arnoux's beaked whale, little is currently known about its biology (1) (5). Like other beaked whales, this species is an accomplished diver and, like Baird’s whale, probably forages on the sea-bed at depths of between 1,000 and 3,000 metres (4). The exceptional diving abilities of Arnoux's beaked whale also allow it to enter regions covered by sea ice, where it may travel up to seven kilometres between breathing sites, locating them with uncanny accuracy (1) (5). Such behaviour may offer the benefit of access to this species’ preferred diet of bottom-dwelling and pelagic fish and squid without competition from other predators (1) (5).
Although this species is generally encountered in groups of six to ten individuals, reports of congregations of as many as 80 have also been recorded (4)