Hi , we have one male jap quail in with 4 female Chinese quail in what has been a very happy living arrangement for some 6 months . Recently I've noticed him becoming very aggressive with the females , grabbing their feathers and chasing them around. Is this normal behavior or is there something wrong with him? They're all mature adult birds but have never exhibited this behavior before and the females are not aggressive towards him. He has also started calling in the evenings. Am just a bit worried as the females have bald heads now from him and so am wondering if I should be removing them but then he would be on his own which is perhaps less than ideal as well. any ideas?? please note , it is spring/early summer here if that hinges on behavior at all?