It is a genetic deformity that causes Charcoal hens to not lay eggs. The cocks are fertile and when bred to a hen that is split Charcoal they can reproduce so you must use a split to Charcoal hen and a Charcoal cock to make more. The Charcoal cock is a very beautiful bird but they also are prone to going blind and dying within a two to four lifespan. There are a few exceptions that will live a little longer but they are rare. It is for this reason most reputable breeders no longer continue breeding Charcoal, the few that do raise them sell to taxidermists for mounting when they achieve the first full train.
