You live in a forested area, you said. A coyote, fox or bobcat, especially a bobcat, can take a bird without leaving feathers, I hate to tell you. I do hope your birds are still around, however, I know of a 12 lb rooster taken from the porch of a friend's home in a short space of time without the loss of a single feather (he was bright, blazing red). She searched through the woods and never found a trace of him. The ONLY thing that could take a rooster that huge, silently, a very predator-experienced rooster in her area (Kentucky) without any other roosters alerting or any sound would be a bobcat, IMHO. It does happen, unfortunately. You have other local predators as well, such as fishers. I have heard that they are much further south than they used to be, too. Oh, joy.
I'm holding out hope your girls will return, but prepare yourself. Reality can really bite sometimes. My neighbor across from my driveway has two Golden Comets as well, super sweet gals, so I can imagine how you must feel. I'm sorry you're having to stress through it, but such is the risk of free ranging in a predator-rich environment.
