It appears as though we have a hermaphrodite chicken. The Welsummer chicks can be sexed at a day old and we were certain this chick was a pullet (female chicken under a year old). As she grew it was obvious that she was definitely a pullet. About a month ago we had a friend over who is our local chicken expert and she noticed immediately. The first sign was the rooster feathers and upon closer inspection she is growing a comb and is getting the head feathers of a rooster as well. I was bummed because we were down to two Welsummer pullets, and I am more excited about the eggs out of this breed than any of the others.
Fortunately, my chicken expert friend has several Welsummer Pullets and I was able to buy two more from her. So, once again I am up to three, and hoping I don't lose any more. I looked up a bit about hermaphrodite chickens. I believe that this one started life as a pullet. In the last couple months she injured one of her ovaries and her body began producing more testosterone. I don't think she will ever lay any eggs. Should be interesting to see how closely she resembles our other Welsummer rooster.
I've shared this photo before but here it is again. You can click on the pictures to see a close up. This is a regular Welsummer cockeral and pullet. You can see how the chicken in the top photos looks like the pullet but is beginning to look like the cockeral.