America’s most sociable bird is getting ready to pack up and head south for the winter in the next couple of weeks. That would be the purple martin (Progne subis), whose usefulness was already recognized in Appalachia by the early Cherokees, who hung bottle gourds horizontally on long poles to attract them. Not only did the birds eat prodigious amounts of insects, but they also (and still do!) drove crows away from cornfields and vultures away from meat and hides hung out to dry.
Purple martins are the largest member of the swallow family in North America and the only species of martins on the continent. Worldwide, there are more than 70 kinds of swallows and martins. Appalachia has six kinds: purple martin, and barn, cliff, tree, northern rough-wing, and bank swallows.
One of the great myths, one of the things that makes the uninitiated want to attract martins to their land, is that each bird can eat 2,000 mosquitoes a day. Martins, like all swallows, are indeed aerial insectivores. They eat only flying insects, which they catch in flight. They are not, however, prodigious consumers of mosquitoes. Martins are daytime feeders, and feed high in the sky; mosquitoes, on the other hand, stay low in damp places during daylight hours, or only come out at night.
Purple martin pest control efforts are impressive nonetheless: their diet includes dragonflies, damselflies, flies, midges, mayflies, stinkbugs, leafhoppers, Japanese beetles, June bugs, butterflies, moths, grasshoppers, cicadas, bees, wasps, flying ants, and ballooning spiders.
Did you know that purple martins in Appalachia are completely dependent on humans to supply their nestboxes (birdhouses) in order to breed today?
So while the martins are spending the non-breeding season in Brazil molting and gaining a new set of feathers, perhaps you’ll consider reading up on how to house them and how to care for them come next spring?