A CHICKEN shocked its owner by apparently changing sex going from an egg-laying hen to a crowing cock. One-year-old Gertie has grown a distinctive comb, red flaps under its chin and has even begun to crow at dawn so his owners want to re-name him Bertie. Jeanette Howard noticed the difference when Gertie began to walk differently from her two other hens, Daisy and Gracie, but was reassured by her vets there was nothing wrong. She said: I bought three chickens a year ago, and they were all laying eggs for me until the end of the year. They began to moult over the winter and I wasnt taking a lot of notice. Then one day I heard this noise, and I thought Wheres that coming from? I looked into the garden at Gertie and I saw it was coming from her or him. Mrs Howard, of Priory Road, Needingworth, saw that Gertie had grown a scarlet comb, chin wattle and long tail feathers, all male characteristics. It had started cock-a-doodle-do-ing, and had grown bits all over its face, said Mrs Howard, 79. He had really grown, and was strutting around with his head up in the air, proud of himself. I shall have to stop calling her Gertie now and start calling him Bertie. Mrs Howard said her three hens had been laying eggs every day before the start of the winter, but that since then their laying has been more infrequent. Startled at Gerties transformation, Mrs Howard and her husband Jim searched the internet for precedents, and discovered that the condition affects up to one in 10,000 animals. Delia Richter, a vet at Cromwell Vets in Huntingdon, said that damage to the hens single ovary, or a growth upon it, could cause it to exhibit male characteristics. It would still be a hen but the ovary on the left side degenerates and the right side begins to release testosterone. Its possible thats what happened in this case, she said. Mrs Howard insists she will keep Gertie, despite his no longer supplying eggs. I just thought Gertie wasnt laying because she was miserable. But Ive got to keep him now I couldnt wring his neck after what hes been through.