Snow Geese, or ducks. But there are many, much smaller birds that journey south, each fall, and return each spring to the Northern Plains.
Goldfinches come all the way back from Louisiana.
Cape May Warblers arrive from the West Indies. Northern Orioles make it back from Columbia. Rose-Breasted Grosbeaks travel up from Mexico. And Bobolinks return all the way from Brazil. A journey of 5000 miles.