I have had one Rooster(Rockey) and one hen for a year now he just crowed for the very first time at 3 am not 5:30 and trust me u can set UR clock to my boy always same time,same crow! Lol Anyways I just got new females so I thought it was that, I go out there sure enough scurrying away from my house is a Raccoon. So I thank God he is smarter and hears better then me plus I think the new girls are a bit too why he still is crowing now at 3:45 because Coon is gone. I'm not sure but I would say different roosters crow for different reason's and we need to realize mother nature,God has put there instinct in them for a reason that we don't always need to understand just make sure they're safe try to go back to bed.