My Bared Rock Rooster's comb is turning black at the tips. I live in Texas and its August, so no frost bite. Here's the thing... iv been watching him for a while and his comb will be bright red one day and the tips will turn black the next. His comb was a healthy red yesterday, and now today it looks like this...(see photo). Also, he has no other visual symptoms, he is a free range roo, with two hens. He crows good and is very active.