Purple Martins
are a passerine bird in the swallow family Hirundinidae. It is the largest swallow in North America. Despite its name, the purple martin is not truly purple.
Most Purple Martins that breed in eastern North American probably migrate across the Gulf of Mexico. They form huge roosts (of several hundred thousand birds) in late summer along the Gulf Coast from Texas to Florida. Others may fly over Mexico and through Central America.
Purple Martins are aerial insectivores meaning they eat flying insects hence why they migrate.
Breeding
Migration
Nonbreeding
Purple martins swarm -- the correct term is staging -- all over North America, a prelude to their annual migration to Brazil, where they will spend the winter. Ninety percent of the Purple Martin population would be gone without the help of artificial housing.
Invasive
species like European Starlings and House Sparrows often push Purple Martins out of local areas by taking over all of the nest sites, including houses that people put up specifically for the martins.
Putting up a Purple Martin house is like installing a miniature neighborhood in your backyard. In the East, dark, glossy-blue males and brown females will peer from the entrances and chirp from the rooftops all summer. In the West, martins mainly still nest the old-fashioned way—in woodpecker holes.