This is a European Starling. It is an invasive species released in America back in the 1800s. 100 were released back then and now they are a plague across America and Canada. They often steal nest holes from native species. I watched as a Gilded Flicker, who had been working on a nest hole in a Saguaro Cactus in Arizona, flew off and this Starling flew right in and took possession of the hole. The Gilded Flicker that worked on this hole was not happy. It was yapping loudly from a nearby tree when it discovered that its hole had been stolen right out from under its beak.