I have read a few places that many cuckoo marans can be sexed by color at birth: lighter ones will be male. I also saw the hatchery video where they look wing feathers: 1 length female, 2 lengths male (I think). When I left for work, I had 4 CM chicks in the brooder, 1 zipping and 1 pipping in the incubator. I can't wait to go home and take a guess. Any other suggestions for sexing the breed? I know I wont KNOW until they crow, but I DO LOVE to experiment! BTW- The first chick to hatch came from a littler egg, but was a HUGE CHICK with a wicked comb. It was like someone had stuffed Bubba in a clown car. Oh! Looks like it found it's name! I could write a book! The Comically Cramped Adventures of Bubba in a Clown Car.