With the Black Copper Marans or Blue Copper Marans, whichever you have, as the rooster:
1. BCM and barred rock. – Black Sex Link
2. BCM and Dark Cornish. – Probably a decent dual purpose meat bird, should have larger than average breasts for a dual purpose.
3. BCM and light Brahma. – This is a tricky one. It could be a red sex link but it may be really difficult to see the difference. You’ll probably need to see both male and female chicks side by side, but there may possibly be a small area on the head, likely the chin area, if there is a difference. You may not be able to tell the difference at all.
4. BCM and Black sex link . – There are a lot of different ways to make a black sex link. Depending in who the parents are you could wind up with a rainbow of color/patterns.
5. BCM and Easter egger – If the Easter Egger hen is laying a blue or green egg, you have a possibility of getting pullets that lay colored eggs, almost certainly green instead of blue. Exactly what shade of green is uncertain but probably fairly dark. Egg shell color genetics can get complicated and you sometimes get some real surprises so don’t be shocked if you get a surprise shade, but probably dark. You could get a pullet that lays a brown egg, even if the EE mother lays a colored egg. If the EE does not lay a colored egg, the pullet’s eggs will be some shade of brown.
Since EE’s are generally of mixed genetics you could easily get a rainbow of colors/patterns in the chicks.
If you know which chick came from which egg a lot of this becomes a lot easier. If the chicks mix after they hatch so you don’t know which hen was the mother it can get really confusing.