Sex on the beach: pressures of extreme polygamy may be driving southern elephant seals to early death

A southern elephant seal bull mates with a female on a beach. The species exhibits ‘extreme polygyny’, in which the largest males – known as beachmasters – control harems of breeding females. Photograph: Michael Nolan/Getty Images/Collection Mix: Subjects RF

Extreme polygamy may be driving male southern elephant seals to early deaths, new research suggests.

A study of 14,000 southern elephant seals (Mirounga leonina) at Macquarie Island in the south-western Pacific, has found that while survival rates for males and females are roughly comparable for juveniles, male survival rapidly decreased after eight years of age, dropping to around a 50% survival rate, while female survival remained constant at 80%.