I have soooo many Junco's this year and they are total bullies, they intimidate the chickadees, the titmouses, the goldfinches and just about any other except the nuthatches who come with their "swords". The cardinals , although so much bigger are pretty tolerant of the smaller birds. Another bully is the dreaded Blue Jay and I often shoo them off after a few minutes. A favorite of mine is "Big Bird", a Red Bellied Woodpecker and he pays no attention to the other birds, is just intent on the suet and an occasional sunflower seed.