But Nico de Bruyn, a marine mammal ecologist at the University of Pretoria working with other South African and Australian researchers, has found that as many as half the females from the Marion Island colony are avoiding the harem system and the male bullying on the beaches. The message seems to be: If the males want to mate, they will have to do it in the water, where the females are on more equal terms.
"For a male, even if he is huge in comparison to the female - which they are - coercing a female is so much more difficult in the water because she has more options," de Bruyn said in an article in Inside Science.
The behavior has not been observed in other elephant seal populations.
"We have no evidence that it occurs in northern elephant seals. I'm not even sure how prevalent the observation is for southern elephant seals," said ecologist Daniel Costa of the University of California, Santa Cruz, who leads a tagging program for northern elephant seals in the Pacific.
Elephant seals were nearly extinct at the end of the 19th century. Humans hunted them for their blubber until both species, the northern and southern elephant seals, were down to perhaps 100 individuals.