Home & Garden

RICHMOND, Ky. — When Kent Kessler bought 20 acres outside of town four years ago, he was hoping it was more than just a good site to build a new home.

"I put up a purple martin box that first spring, and by the time we moved in, we had an established colony," said Kessler, a lifelong birder who grew up in rural Jefferson County, east of Louisville, Ky. "My dad and I tried for years to get purple martins to nest on our land, but they wouldn't come."

According the Purple Martin Conservation Association Web site, the birds have specific aerial space requirements. Purple martin houses should be erected in an open spot, 30 to 120 feet from human housing, and no trees within 60 feet should be taller than the bird houses. Having a pond or lake nearby is a plus.

East of the Rocky Mountains, purple martin populations are completely dependent on humans for nest sites. There are two sub-species in the western states that nest primarily in abandoned woodpecker nest cavities.

Each year, purple martins fly thousands of miles a year during their migrations.

Purple martins are completely habituated to humans and don't seem alarmed when their nests are inspected. They fly around while the birdhouses are opened, then they fly back to check on their nests after the box is back on the pole.

For hundreds of years, purple martins nested in large gourds. Today, many birders erect plastic nest boxes shaped like gourds. "The birds really like that gourd shape. The nest boxes are white to reflect the hot sun and have slide-out nesting trays," Kessler said.

Predators attracted to eggs and young purple martins in the nest include raccoons, rat snakes and owls. "Starlings can be a problem too. They try to nest in the boxes and will poke holes in martins' eggs and kill young," Kessler said.

Having purple martins around has its advantages, besides an endless aerial acrobatic show. They are insectivores that eat a wide range of flying insects, including flies, wasps, Japanese beetles, cicadas, gnats and moths, "but not as many mosquitoes as people think," Kessler said. "Martins are on the roost (in their nest box) at night when most mosquitoes are out."