Sounds like a classic coon attack. I just lost my favorite 'exotic' rooster to one of those #$%$!!! things. My three dogs usually chase racoons off or tree them (the dogs are trained to leave chickens alone). When they do the latter, I shoot the. . . well, this is a family site. Racoons are most likely to strike right at sundown or sunset. Their attacks occur in late winter/early spring, when the weather warms up (they don't hibernate, but hunker down in cold or extreme weather) and around July when their young are weaned. This is the worst Time! I once shot three out of a tree in one assault. Up until this last attack, I thought the coons had agreed to an armistice. No such luck.