Superalliance of bottlenose dolphins

It is found that male bottlenose dolphins at Shark Bay, Western Australia, form two levels of alliance within a social network of more than 400 individuals, with 14 of the males forming highly labile alliances, rather than the more typical stable ones.

Abstract

It is quite common to find several levels of nested male alliances in human political organization1, 2 but these are extremely rare in other species3. Yet we found that male bottlenose dolphins (Tursiops sp.) at Shark Bay, Western Australia, form two levels of alliance within a social network of more than 400 individuals. Fourteen of the males formed highly labile alliances, rather than the more typical stable ones, and joined forces in a large ‘superalliance’ that competed directly with smaller teams of stable alliances.