Successfully attracting the mosquito-loving purple martin to your property involves more than simply hanging a birdhouse. Purple martins rely on humans for shelter. They require houses of a certain size in specific locations and placed at a safe distance above the ground.
Experts on purple martins suggest mounting martin houses on metal poles between 10 and 20 feet above the ground surface. To prevent the pole from falling, a taller pole—with two to three feet set into the ground—is required.
Entrance Hole Height
The entrance holes of purple martins also must be placed at specific heights in relation to the floor of the birdhouse. Maryland Cooperative Extension and University of Florida IFAS Extension both suggest placing the entrance holes one inch from the floor.
The mounting height for the purple martin birdhouse is meant to provide the bird with an unobstructed entrance and exit flight path. A house should not be placed near trees or other structures that might block the flight path.