I believe they are kept away by one most belligerent male red-bird, who has set up an arbitrary order of feeding for all other birds who come to what he considers his own boarding house.

我相信它们被一只最好斗的雄性红鸟赶走了，它为所有其他来到他认为是自己寄宿处的鸟儿设定了任意的喂食顺序。