Tail feathers: Cock tail feathers are generally longer, while hen tail feathers are generally shorter.
Beard: A rooster's beard is not as developed as a hen's.
Hairy crown: the hen's hairy crown is more developed, just like white wool balls.
Ear lobe: In adulthood, the ear lobe of rooster fades faster.
First, the comb
Black-bone rooster's comb is larger, purplish red or big red, with a cluster of teeth, like a wonderful flower in full bloom, while hen's comb is smaller than rooster's, mulberry-shaped and black.
Second, the tail feather
The tail feathers of black-bone chickens are generally longer, while those of hens are generally shorter.
Third, the beard
There is a thick tuft of fluff (that is, beard) on the lower jaw of black-bone chicken, in which the beard of cock is not as developed as that of hen.
Fourth, the hairy crown
There is a tuft of silk hair (that is, hair crown) on the head of black-bone chicken, in which the hair crown of hen is more developed, just like white velvet ball.
V. Ear lobe
Black-bone chicken's ear leaves are malachite green or lake blue, just like jade earrings. When it comes to adulthood, the color gradually becomes lighter, and the rooster fades faster.