I have a Blue copper maran rooster that seems to go after my Brahma about once a day. It's normally in the morning when they first get out of the coop. He'll puff up his neck and start chasing her all over the yard and this morning he nipped some a couple fluff feathers off her thigh. Once he did that (granted I did run out there), he was fine and everyone went on their merry way. She's the only one he does that to and I'm not sure why. He doesn't keep her from eating as I've seen them forage together and I've seen them next to each other nesting/roosting as well. It has made her skittish though as she's doesn't seem to want to leave the coop in the morning and she stays on the outskirts of the flock. Here are some pics just b/c they're pretty.