4 of our hens were killed by a dog. We had 4 young roosters and one hen left. One of the roosters stayed with the hens and fought and survived (the rest fled) the rooster that stood up is now super depressed and wants nothing to do with the other birds. How do I help him recover? (No external injuries minus feather loss) (18 more female chicks coming in 2 weeks) should I put them with the rooster? What can I do now?