I'm on my 3rd brood of chickens. The former 2 were Rhode Island Red + Bantam mix and the boys started crowing* at 8 weeks.
This one is a backyard mix of banty eggs I got from a guy who had a ridiculous amount of chickens and other fowl (there were a pair of peacocks in the chicken pen....)
All the eggs were the same size, and I think most had the same mom because 6 of 7 are black. At 8 weeks, only 1 shows signs of being a boy. The "Black sheep" of the family looked like a chipmunk when she was born, and looks like she may have been sired by a normal sized silkie roo because she's a chunk bigger than her nestmates and I can't tell at all whether she might be a roo.
Of the 6 black chicks, one developed a comb and wattles already, and has brown saddle feathers that all started coming in at about 2 weeks -- so I've been swearing he'd start crowing at 8 weeks. Here we are -- 8 weeks and not a peep. Actually, a lot of peep, but not much hint of any other noises from him, though I do occasionally hear some "more mature noises" from the brood like their vocal chords are starting to develop (do chickens have vocal chords? they must have SOMETHING to make the range of noises they do....).
I have no roosters right now to model crowing to this bunch, just this one lone cockerel and whatever mysteries have yet to unfold from the other 7 babies. If the silkie mutt is a roo, I don't even know how to tell. She does have thick legs, and the extra thumb, but I can't tell silkie roos from silkie hens in the first place...
I also raised my first 2 broods indoors and this batch is being raised by one of my first RIR-banty hens, free ranging, and she's completely the doting mom. Maybe he doesn't feel any need to exert authority yet. But I saw him looking at one of the other hens today like "Hrm, you're really interesting..." before running off to chase after mom & siblings....
* "Crowing" meaning "sounding like a broken trumpet" or occasionally like an old rope-and -pulley laundry line in bad need of grease.
