I'm not that certain if they are sex linked because whey were born with yellow legs the pure breed were born with green legs, we have sexed them and seems we do have 2 cockerels out of 11 chicks which 3 of them are pure breed ameraucana and 3 are buff brahmaXAmeraucana cross and 5 are buff orpingtonXameraucana cross, only one brahma has yellow legg and its a she(hen/poulette) and one bufforpington cross to Am that has also yellow legs and its a he (cockerel/ young roo), in total we have 3 males and 8 females (1 male orp X am yellow leg + 1 male opr X am greenish leg) and 1 pure breed AM with normal dark green legs, some of the cross breeds has muffs and beards, and some dont. What i have noticed is that the cross breed grows faster and did hatch at day 19 under a temp of 99.5 F +/- 37.5•C in a hovabator still aire and manualy turned, they are 4 weeks now and one weights 301 grams,I have now (22 eggs in total now in an homemade incubator)5 are pure breed orpington and 10 are Ameraucana pure breed 1 buff brahma crossed to a buff orpingtom roo and 6 layer X ameraucana hopefully this time some layers egg would hatch i have used eggs before from an old layer and they developed nicely but died at day 18 +/- I'm trying to hatch eggs now from a young layer now which was only fed compleetly natural seeds, insects, oyster shells, fruits and vegies scraps, grass, oatmeal and corn.
If any one had succesfully cross any kind of layer to an Am roo and had chicks let me know and how they turned to be, my layers are rhode island cross