Yes, Marans are their own breed, Cuckoo is just a variety Marans, ( there are also Black Copper, Black, Blue, Wheaten, etc, if you have one with feathered leggs, I think that would be good, I think cuckoos with feathered leggs are kinda rare, since cuckoos are sold by hatcheries and most hatchery Marans don't have feathered leg, so he shouldn't be mixed, most people want their Marans to have feathered leggs. I have 5 Black Copper Marans and 1 young Cuckoo, 1 of the BCs and the cuckoo don't have feathered leggs, but they are all still marans.
Where did you get him from? Cuckoo Marans should have blurred Barring, white leggs, and like I said, may or may not have feathered leggs, depending on how they are bred. But since the dark egg color is what "SELLS" a lot of people put the physical characteristics aside and just breed for dark eggs, some don't even worry about the egg color and just breed what they have.
Do you have pics of your roo?
Where did you get him from? Cuckoo Marans should have blurred Barring, white leggs, and like I said, may or may not have feathered leggs, depending on how they are bred. But since the dark egg color is what "SELLS" a lot of people put the physical characteristics aside and just breed for dark eggs, some don't even worry about the egg color and just breed what they have.
Do you have pics of your roo?