I would think the EE would kind of throw the Cuckoo chick coloring off so that you could not sex them. I might be all wrong here, but that's my 2 cents worth. Someone else with Cuckoos will probably answer it better for you.Hello, I was hoping someone could help me with a question about sexing chicks. I just hatched out 6 Olive Eggers. The cross was a Blue Cuckoo Marans roo over EE's. The lady I got the eggs from told me that she has been getting Blue cuckoo with feathered legs some beard and muffs. Is there a way for me to sex the chicks? Head spots, color? Does the EE in there throw that off? One of the chicks looks black with yellow, the others are varying shades of blue. One is clearly lighter blue with a mostly yellow head.