Hm, how old are they? I'm guessing about 6-8 weeks, but I'm probably wrong
Your BO could be a roo, but I'm not seeing a whole lot of red at the moment. I'm sure it varies, but my rooster started getting dark red in his comb by 5 weeks and had a fully red comb by about 8.
I would hold on to your Maran--she still looks like a pullet to me.
Hopefully others will chime in who know more about Marans. I'll keep my fingers crossed for you!
Think the BO is a Roo, The maran is to early or not enough info,mine all had the same size comb that all turned out to be hens. The BO's legs look real thick and comb is pretty large so Roo is my guess
How old are they? My BO boys look something like this
They get those darker, shiney feathers at a pretty early age. The cuckoo Marans looks like the girls my neighbor has running around. Some shots from the side and looking down on their backs would help with sexing them. Then we could check out the saddle and hackle feathers...
Hmm by looks of the tail of the BO I think its a pullet. Mainly because I have a BO and she had a very large comb also. So You just really cant tell....