Thanks! This is super helpful. I was thinking rooster because of the tail feathers and longer neck feathers, too. I haven't had a rooster since I was a child and now out of thirteen chickens, we have (hopefully) only two roosters--this one and a gray silkie that crowed at me for the first time this morning (I couldn't get a repeat performance for the rest of my family). This brahma doesn't make any noise at all yet, although I'm guessing he (?) will soon since all the chicks are the same age.
Does anyone have experience keeping a bantam and regular size rooster? We have a large coop and run, but it's not huge. And I let the chickens out for the first time tonight in our enclosed yard and even though I kept an eye on them, our smallest silkie disappeared, so they're going to spend most of their time in a predator-proof coop and run.