The ostriches showed signs of courtship behaviour

A study found that the birds were directing their courtship rituals at humans rather than their own species.

And Dr Charles Paxton, a statistician and ecologist at St Andrews University, said it was lucky that the farmers did not venture into the ostrich pens.

"You would not want to go into a pen with an amorous ostrich," he said.

"Ostriches weigh a great deal and have very sharp claws. It would be very, very dangerous indeed."

Spoof prize

Dr Paxton's findings have been published in the journal British Poultry Science.

His research also earned him an Ig Nobel award, a spoof prize given annually for achievements that "cannot or should not be reproduced".

Dr Paxton will be giving talks on his study in Manchester and Edinburgh in the coming days as part of National Science Week.

The research was carried out in Oxfordshire during the ostrich farm boom of the mid-1990s.

What we found was that these animals were mostly displaying courtship behaviour directed at the farmers

Dr Charles Paxton

Dr Paxton said: "The farmers couldn't understand why every time they went to check on their ostriches they saw them engaging in courtship behaviour.

"What we found was that these animals were mostly displaying courtship behaviour directed at the farmers.

"When human beings weren't around, their level of sexual behaviour went right down."

He said that ostriches showed sexual interest in a number of ways.

'Sexually confused'

"The male drops on his knees in front of the female, puffs his wings out, throws his neck out and makes a booming, groaning noise. It is called kantling behaviour," he said.

"The female drops her neck right down to the ground and clicks her beak."

Dr Paxton, who observed the birds with colleague Charles Deeming, said the behaviour did not depend on the sex of either the farmer or the ostrich.

He believed the birds had become sexually confused after being raised from birth with humans.

One male that mated properly with females of his species had been reared in a zoo with other ostriches.