These are what we think are rosy breasted finches and they are becoming a pest. First one will show up at the feeder and then when they leave hundreds come back and swarm the feeders. They can drain the feeder in a matter of a few minutes and the other birds are chased or forced off and don't get any feed. When they swarm in the sky will literally be full of them and we chase them off but they come right back. They fight each other over the few ports on the feeder. They simply take over the feeders and the other birds are shut out.