Brand new to BYC, but have visited the site/forums for months now and find this to be a great community.
To kick off, wanted to make a quick post about our experience with our handsome Welsummer Roo. He's quite the character - very gentle and good with the girls. He's just turning 15 weeks and there is no longer any doubt of his gender. We started to be able to tell very distinctly at about 9-10 weeks that he was our boy (which we wanted).
I'll post some pictures, but the tell-tale sign for us at 9-10 weeks was his head. He began to get light brown, fuzzy feathers on his head whereas the hens feathers were darker and more sleek. He was also bigger than the girls and his feet were more yellow than the hens. Lastly, his comb started to develop earlier than the girls.
I only post this because there didn't seem to be a lot of definitive information - anywhere - on distinct differences in gender for Welsummers. We got our chicks from Meyer and they were great to deal with throughout the process.
Glad to be here - hope this helps somebody.