Hi,
I was thinking about asking the same thing. I have a Frizzle that I THINK is a rooster, as it looked to me that he/she was trying to mate with one of my other hens, but I haven't heard a sound out of him/her.
I have seen other roosters mating with hens so I think I know what to look for. He/she had the hen by the back of her neck to hold her still and he/she was on top of her.
However, the Frizzle is only about 5 months old, so that could be a factor.
I thought the crowing comes before the mating. Anyone else had an experience like this? Thanks! Genie