I decided to start a new topic on the subject of half siders because I believe what I have is a half sider and not a gynandromorph. Now that it has matured, it looks and acts like a hen and has begun laying eggs. I have been researching and the only information I could find on fertile half sider birds are of parakeets or parrots that have a defect in the yellow green alleles. Is it possible that my chimera could be from two female embryos fused together rather than a male and female (which would create a gynandromorph)? I have a feeling that these same sex half siders are much more difficult to spot than gynandromorphs in birds because they are usually all one color.