I have 8 7-wk old Barred Rocks from McMurray. I thought I could separate males and females at a young age and that only 2 were pullets. But, 3 of what I thought earlier were cockerels were slow to feather, and now that they are feathering, they look in color more like the pullets. Still they don't look quite like the obvious pullets that feathered early.
Here is a photo with 2 of the early feathering cockerels - obviously males.The one you see the back only of - between the NH and BR, is one of the late feathering questionable birds.

Here is another picture of one of the birds whose gender I'm wondering about.


The same questionable bird on the right, and another of the slow to feather ones behind the NH cockerel.

You can see the lighter colored cockerel behind the feeder, but the other 5 birds are a mix of what I am pretty sure are pullets and the slow-featherers. They are all much darker than the 3 obvious males. Is it possible that even thought they are darker and don't have comb development yet, that they might be slow-maturing cockerels? The one that is hardest for me to see as a pullet is on the far left - same bird featured in above photos, with the turned up tail.
Here is a photo with 2 of the early feathering cockerels - obviously males.The one you see the back only of - between the NH and BR, is one of the late feathering questionable birds.
Here is another picture of one of the birds whose gender I'm wondering about.
The same questionable bird on the right, and another of the slow to feather ones behind the NH cockerel.
You can see the lighter colored cockerel behind the feeder, but the other 5 birds are a mix of what I am pretty sure are pullets and the slow-featherers. They are all much darker than the 3 obvious males. Is it possible that even thought they are darker and don't have comb development yet, that they might be slow-maturing cockerels? The one that is hardest for me to see as a pullet is on the far left - same bird featured in above photos, with the turned up tail.