Social Structure of Pilot Whales Revealed by Analytical DNA Profiling

Abstract
Long-finned pilot whales swim in large, extremely cohesive social groups known as pods. Molecular typing revealed that pod members form a single extended family. Mature males neither disperse from nor mate within their natal pods, a situation unusual for mammals. Such behavior could be explained in terms of inclusive fitness benefits gained by adult males helping the large number of female relatives with which they swim.