On February 4, 1821, near New Orleans, John James Audubon sighted Purple martins “gambolling through the air.” The “Fahrenheit’s thermometer” that Audubon held “stood at 68 degrees, the weather being calm and drizzly. This flock extended about a mile and a half in length, by a quarter of a mile in breadth.” If this flock could be considered close to or the equivalent of two and a half million birds, then the number is the most Purple martins anyone else has counted in North America according to Cornell’s e-Bird system (see eBird Checklist S190089179). Kat Casey counted the birds on the evening of August 2, 2024, in Austin, Texas, which over the years has proven to be one of the most popular gathering places for Purple martins in the late summer.
It is most likely that Anglo-European settlers learned from indigenous people that one way to control mosquitoes or any other flying insect was to have Purple martins patrolling. And the best way to attract Purple martins and their pest control services was to offer a nesting site consisting of a hollowed-out gourd with a two-inch hole carved into it, as shown in Birds of America. And if gourds for Purple martins were placed close to barnyards, the birds also helped protect chickens and other domestic fowl while working tirelessly to fend off hawks, cats, and other threats to their nests. Audubon also learned in his wandering ways that an indicator of the quality of an inn was the condition of its Purple martin gourds and boxes: “Almost every country tavern has a Martin box on the upper part of its sign-board; and I have observed that the handsomer the box, the better does the inn generally prove to be.” Purple martins in the eastern United States today rely almost entirely on humans to provide them gourds and boxes for nests.