Bird headed for kestrel box; unfortunately, it is not a kestrel but probably an European Starling. In a classic example of unintended consequences, there are millions of starling in the US, all descended from 100 birds introduced in 1890 by a Shakespeare aficionado who decided that every bird species mentioned by Shakespeare should be introduced into the United States. His original colony was in Manhattan's Central Park. They are throughout the US now. They are cavity nesters and therefore are in competition with native birds.