How old are Roos when they first crow

[lastonein]

I have some barnyard mix chicks that are 8 weeks and one of the crows. It is the cutest thing could he be a bantam?

 

[rockstar]

I have noticed some of mine start making attemps of crowing as early as three weeks. When I first got chickens four years ago, I though they all had to be mature before they crowed. My first roosters didn't crow until around 6 months. I was sure surprised when a broody hen hatched chicks and one of the little ones started showing himself around three weeks.