A European starling (or possibly more than one) has been visiting my yard lately. Many people think these iridescent speckled black birds are pests; they are an ‘invasive species’, they were brought into america when 100 birds came to New York on some ships. When searching for nests, they often will kick out other nesting birds & kill the young, then take over the nest. They also often eat crops. In their native homes in Europe & western Asia, they weren’t a problem, because the other species there could deal with them, but here there are bird species not accustomed to them, & they can create a big problem. The same is true with House sparrows. They catch a lot of insects though, & they’ve never been a problem around my yard; it may be that they don’t bother with the nests the birds here make. They don’t (as far as I know) eat sunflower seeds, instead they hang around in the tall grass searching for insects.