Merritt Purple Martins are the only North American species of songbird entirely dependent upon human-supplied nesting cavities for reproduction. Over one million North Americans put up housing for Purple Martins. Unfortunately, many of these folks are unsuccessful. Hopefully the following information will increase your chances of attracting Martins. Once purple martins nest successfully at your location, they will come back year after year if you manage the site properly.
Good management can prevent or minimize most of the problems that can lead to site abandonment.
For a colony site to thrive, landlords need to conduct weekly nest checks, control House Sparrows and European Starlings, and be prepared to deal with problems. Location Purple martins have fairly specific space requirements. Place housing in the center of the most open spot available, about 30-120 feet from human housing. There should not be any trees taller than the purple martin housing within 40 feet, preferably 60 feet. In the southern half of their breeding range, purple martins are less particular about house placement.