Purple Martin Mania
nape of the neck.
Sub adults are more easily attracted to new sites. A sub male may hang out for several weeks at a new site trying to lure in females, which are more finicky house hunters.
Pairs construct a flat nest of straw and spongy plant stems, sometimes adding a mud dam at the entrance. They line the nest bowl with green leaves. They refresh those leaves often to cover the eggs when the female is out feeding.
Broods of older birds fledge around late June, while the broods of sub adults fledge in late July.
Forums for ‘em
Purple martins are benefiting from the Internet. Many devoted landlords now turn to online forums for helpful information. One of the most popular is at www.purplemartin.org. It’s the site of the Purple Martin Conservation Association (PMCA), a nonprofit advocacy group devoted entirely to purple martins.
Leverett W. Doehring of Villa Ridge in Franklin County, southwest of St. Louis, said information from PMCA forum members helped him grow his colony. Last year, he had 86 pairs with just two vacant compartments.
“A lot of people think you can just put up a house and get martins,” Doehring said. “And, you might get a few, but for a colony to grow, you really need to apply some very specific techniques.”
Much has changed in the last decade in “martin management.” Houses now have deeper compartments to stimulate larger clutches and help protect nestlings from predators, especially owls. Many of them also have specially designed entrances that restrict starlings.
Serious landlords tend to become amateur wildlife biologists, keeping detailed records of purple martin behavior and nesting success. Their diligence will likely result in even more refined techniques for caring for purple martins in the future.
Doehring sat on his deck one evening reviewing notes on egg clutch size, projecting fledging dates, and pondering adding a few more housing units.
“It would be nice to reach 100 pairs,” he said. “I just can’t imagine sitting out here without them.”
Location! Location! Location!
The biggest error you can make when setting out a purple martin house is to put it too close to trees. Open sites, or at least sites with open flyways, attract more martins.
Curiously, martins also seem to prefer nesting in the vicinity of human activity.
Recent findings suggest that the 12-compartment aluminum house with 6-inch by 6-inch rooms that has been widely used since the 1960s is due for a makeover. Experts suggest deepening compartment size to 6 inches by 12 inches. Adding starling-restricting doors is also necessary, because both starlings and martins prefer the deeper compartments.
Many landlords also are putting up natural gourds or those made from PVC. Gourds give martins room and help protect their nests from rain and predators.
Successful landlords invariably suggest aggressive control of starlings and house sparrows. These nonnative species are not protected and can be removed by trapping or shooting.