We have a RI red rooster only 9 weeks old who is a little overprotective of his girls. The other day he would not let them out of coop due to a wheelbarrow parked to close to the fence. Will he mellow out as he gets older?
In terms of weight he probably only 25% grown and in a set of feathers that is not yet adult. He is far from being a rooster in respect to behavior. Presently, he is the larger chick that more likely than not is behaving in a selfish manner by picking in flockmates.
True rooster behavior will not be realized until he is 20 weeks or better and it is from that point mellowing will occur. With my birds that are significantly slower to mature, full adult behavior not realized until a good 32 weeks of age and even then with roosters, usually some futher mellowing expected.
I had a roo once who was a roo from the get-go. He worried and fretted about his girls ALL THE TIME, and it started when he was a tiny chick. He came in a batch of sexed layers, but I knew from the start that he was all boy.
He turned out to be a wonderful protector, and proved it about a year later when he sacrificed himself to save the girls from a big husky. Brave boy!