Male topi antelope's sex burden
Some males are so forcefully pursued by pushy females that they refuse the advances of previous partners.
According to research published in the journal Current Biology, this helps males conserve their sperm for the possibility of mating with new females.
It therefore increases the chances of fatherhood with the widest possible number of partners.
Dr Jakob Bro-Jorgensen, the scientist conducting the Zoological Society of London (ZSL) research, said: "In cases where the male antelope was free to choose between females, he deliberately went for the most novel mate, rather than the most high-ranking."
He added: "However, some pushy females were so aggressive in their pursuit of the male that he actually had physically to attack them to rebuff their advances."
The research was undertaken in the Masai Mara area of Kenya, in the traditional breeding grounds of the topi.
clipped from: news.bbc.co.uk