Mr Marks, whose findings are to be published this week in Nature Australia magazine, says the first successful captive breeding of wombats was recorded in Hannover, Germany, in 1982. "With absolute precision, details of the wombat's sex life were recorded and, surprisingly, it seemed anything but modest," he says.

"It appeared to be a physically demanding process, complete with chasing, biting, grunting and loads of heavy breathing." Then in 1990, Mr Marks filmed the first common wombat courtship and mating in captivity in Australia, at Tonimbuk Farm in south-eastern Victoria. "The female, after a prolonged period of copulation in the same position, broke away and began to trot in a pattern of circles and figures of eight.

"The male chased her, following closely behind, and then bit her on the rump," he says. "She immediately stopped just long enough to permit him to roll her on her side and begin copulating again.

"If the male was slow to mount, she would kick back aggressively and not let him roll her on her side again until she had run round in more circles and figures of eight. This happened seven times." Space seems to be the key. Mr Marks says without the "hard to get" figure eight dance, the female will not allow the male to mount. But zoo keepers are catching on. Mr Marks says biologist Catriona MacCallum at the Western Plains Zoo in Dubbo has had spectacular wombat breeding success.

"Joining and modifying the pen systems to permit a chase, she not only found that wombat breeding was possible in captivity, but she found herself with the first recorded case of wombat twins." Mr Marks says he hopes his study will solve the sloth-like image problem of the common wombat, making the furry marsupials "the symbol of Australian male sexual virility".

- AAP