The Phenomenal Purple Martin

Anyone can be a naturalist. On the Academy blog, our scientists share their knowledge to help you explore the natural world. Doug Wechsler, former director of Visual Resources for Ornithology (VIREO), recommends a summer detour that may help you spot a phenomenal bird.

purplish black bird on branchThe purple martin (Progne subis), named for the coloration of the sheen atop its feathers, is the largest swallow in North America. Growing up to 7.5 inches long, it feeds on flying insects such as beetles, dragonflies, and moths. The purple martin is entirely dependent on human-built birdhouses for nesting. Vigilant landlords evict house sparrows and starlings to prepare for the martins’ arrival.

Human interaction with purple martins dates far back into American history, Wechsler explains. Native Americans hung gourds with holes cut in the sides for nesting birds. John James Audubon (1785–1851) once said there was one purple martin box for every country tavern. Purple martins nest in birdhouses in open areas and migrate to South America for the winter; they return to North America in spring to breed and raise their young.

For a remarkable sighting, Wechsler recommends a visit to south Jersey between late July and late August. For a short time each year, tens of thousands of purple martins roost atop the reeds adjacent to the Maurice River near Mauricetown. They depart each morning before sunrise, and their return at sunset is an event to watch, especially from areas near the Mauricetown Bridge. The birds return in small, unremarkable numbers at first but then rapidly multiply until the sky is filled with a cloud of purple martins, all flocking back to the reeds for the night. If you’re traveling to the shore this summer, you won’t want to miss this spectacular detour.

Search for more animals during your trip to the shore. Then visit the Academy’s special exhibit, Backyard Adventures, to learn about all the cool things living in your neighborhood and your backyard.

This article originally appeared in the Summer 2012 edition of Academy Frontiers.