He's been crowing every morning so unless hens can do that too I have no idea
Ok he's most likely a rooster then... again, I know it seems like a dumb question but sometimes it can happen with silkies. Hens actually can crow, but usually only when they aren't around any other roosters and so they need to become dominant. But if I were you I would follow @DuckMochi's advice... he's most likely just scared because he's been thrown in with a bunch of strangers. So if he continues the behavior I would separate him out, but so he can still interact with the others and so they can establish a pecking order without hurting each other. The biggest thing though, is make sure he doesn't get bullied away from the food or water.
