
diva! I see you've been lurking a little bit! Hope you're doing well.
Julie, as far as what Sandhill subbed rather than blue Jersey Giants, there are blue Langshans, I believe. There are also blue Marans, if I'm not mistaken, but I have no idea if they have those.
With barred birds, if a bird carries one copy, it appears darker, like a BR pullet. If it has two copies (double barred), it appears lighter like a cockerel.
When Atlas hatched, I got Atlas, who is properly double barred, his two barred sisters, plus two solid black sisters, one of those being Wendy. His sire, Rex #2, was single barred, having only one copy of the gene like a black sex link rooster would. Rex was the product of my Delaware rooster and one of the Stukel BR hens.
If Rex had been double barred, he would have given a copy to
all of his progeny. So, Rex gave his copy of the barring gene to 50% of his offspring, roughly. The mothers of that group of his progeny were the Stukel line BR hens. The reason that there were two black girls is that hens
never pass the barring gene to daughters and Rex, being single barred, did not pass his gene to those two daughters, either. He did, however, pass it to Rachel and Rowena.