Earth Almanac: July/August 2008

Hotels on High

The August sun is bright and hot. With so much summer fun left, the last thing you want to think about is winter—unless, that is, you’re a purple martin. Uttering musical chirps and raspy twitters, these large, loud swallows hawk dragonflies and, as the day ends, swirl like coal smoke around trees, rising, settling, finally roosting. Within hours they’ll strike out for Bolivia, Paraguay, and Brazil. You’re apt to encounter purple martins almost anywhere in the contiguous states. And while they’re not as common as a century ago, they’re recovering in some areas of the East thanks to multi-unit “purple martin hotels” erected by bird lovers. The eastern subspecies has been conditioned to artificial nest sites for centuries, first by Indians, who hung out gourds for them. Now it’s almost entirely dependent on nest boxes. Hotels with two dozen or fewer rooms work better than bigger ones. Rooms should be at least six inches on a side, and it’s important to provide good ventilation and drainage. A coat of white paint will help cool nests by reflecting sunlight. Be sure to place the hotels in the open and mount them on high metal poles. And to discourage house sparrows and starlings plug entrance holes until martins show up.