Every once in a while you'll see one of these, I don't know if it comes from domesticated turkeys finding they're way into a wild flock or if its just a gene that becomes apparent every couple of broods. I see bearded hens more than ones like this but they are around from time to time.
Absolutely genetic, in this case a recessive (hypo-melanistic) gene caused a lack of dark pigment. It remains recessive because natural selection tends to kill it off as it occurs. Same thing with 'melanistic' animals, the excessive dark pigment also makes them stand out from the crowd and increases mortality rates.
