I have found that sexing chicks by tails and wings to only be 75-80% accurate with these birds. Even with the pure bred Bresse when I had them. But combine it with other attributes like leg thickness and personality and you can get closer. Some cockerels will get faster growing feathers like their pullet sisters. Usually the pullets will get shoulder feathers first. The boys will retain fuzzy shoulders longer even though their wing feathers are really long. The pic you posted of your newest clean neck boy shows the fuzzy shoulders. But only two times ever have i had chicks i thought were gonna be boys and they turned into pullets... And they have been small ones with strong wild partridge pattern and a nice round breast, as if they had throwback game fowl genetics at play.
At 4 weeks old some of these Dunlap chicks are already getting redder and bigger combs. Interestingly, the only ones left that have the fuzzy shoulders still are the smallest ones.
