I have two cockatiels. The gray ones tail feathers look funky. I can't tell if I have girls, boys or one of each. Also, what to do about the gray one tail feathers. The yellow head one is MC Hammer and the gray one is Jezzy. I need to know if I need to change their names based on their sex. I think MC is a boy and or course Jezzy may be a girl. Any suggestions would be appreciated.