UN scientists are to study a cockerel which swapped sex after a fox raid on his enclosure wiped out all his hens.Gianni's Italian owners say he started life as a red-blooded rooster on his farm in Tuscany.But within days of the fox raid, 'he' was laying eggs and trying to hatch them as he brooded over his new life in the hen house.Now scientists at UN's Farm and Agriculture Organisation are to study the bird's DNA to see what made him change."It may be a primitive species survival gene. With all the females gone he could only ensure the future of his line by becoming female," said one expert.Source: orange news