Male kob antelope, black grouse and those flies that swarm round your head when you stand still for too long in a field are lekking species. Males (it’s almost always the males, but see left) gather together to display their prowess to visiting females, who queue up for the best performers. Dowdier males miss out entirely. Which raises a conundrum: if only the sexiest males’ genes are passed on, why are there still unattractive ones? The ‘lek paradox’ remains to be solved.
Male black grouse raise their tails and inflate their necks while displaying.