A hen who suddenly had a sex change and effectively became a rooster has undergone a gender reversal operation.
Olivia, a female chicken from Sydney’s south west, is one of 10,000 chickens who have a rare syndrome called sex reversal.
One year ago Olivia stopped laying eggs, grew wattles beneath her chin and began to crow.
Sporting her new puffed out chest Olivia began to adopt the characteristics of a rooster.
Her confused owners took her to their local vet in Camden for help on their hen’s puzzling development.
Avian Reptile and Exotic Pet Hospital confirmed she has the rare syndrome.
‘You would be forgiven for thinking that this little lady is a rooster, but looks can be deceiving,’ Avian Reptile and Exotic Pet Hospital said on its Facebook page.
‘During embryonic development, the right ovary remains in an underdeveloped stage where it is neither an ovary nor a testes, it is called an ovotestis.’
The ovotestis usually remains dormant for hens but in Olivia’s case her left ovary was dysfunctional and began to secrete androgen including testosterone causing her to adopt more masculine characteristics.
To stay with her flock and keep her neighbours happy Olivia has her yearly dose of hormone implants placed underneath her skin to suppress the testosterone.
Since the implants Olivia’s wattle and comb have become smaller she has stopped crowing and is back to a more feminine look.
To keep her original look Olivia’s implant is life-long.