Purple Martin
The first of these welcome migrants was seen in Missouri this week after a long journey north from South America. Our largest swallows, they are fast and agile flyers. They swoop, twist and dive as they snap up flying insects. A Purple Martin sings as if he had training for the opera, and many people put up houses for Purple Martins for the joy of having nesting martins. Once martins nest at your location, they will come back every year if you manage the site properly. East of the Rockies these birds are totally dependent on human-supplied housing. West of the Rockies and in the deserts, they largely nest in abandoned woodpecker nest cavities. In the Pacific northwest, Martins are beginning to use gourds and clusters of single-unit boxes for nesting.

Image: Wikipedia