Could be f2 or later; could be a mix of several breeds that have crossed with silkie for that matter. I don't know wyandottes well enough to see it, but that is my lack of experience with the breed, not disagreement. F1 silkie crosses are NOT always silkied--at best 50% are silkied, and that is if bred to another silkied bird. If two f1 crosses are bred together it is only 25% who will be silkied. If F2 and later you get all sorts of appearance variations as the various genes segregate out. F1 crosses tend to be more predictable. One of the mixed blessings when you make crosses