Birds of Oneida Lake - The Purple Martin
by Robert Gang
Bugged by mosquitoes? Put up a purple martin house.
Every spring, around the end of April, the purple martins return to Oneida Lake from their winter nesting grounds in Brazil. The mature birds will return to the same colony year after year. If nesting sites are available, the younger martins will settle at the
colony where they were fledged. However, if the colony is full, they will move on in search of suitable housing. This fact provides you a chance to establish your own colony of these beautiful, beneficial birds. They are a delight to watch and listen to, and best of all, they can keep your lawn and garden free of flying insects. Well . . . almost!
The purple martin is the largest member of the swallow family. The adult male is of a beautiful blue-black coloring with a purple iridescence on its head and on top of the wings. The females and first-year males have a duller, less uniform color, with pale gray breast and abdomen. The female is slightly smaller than the male, who averages about eight inches in length and weighs about four ounces.
They are skillful, graceful fliers and seem to be fond of people. A single purple martin can eat up to 2,000 mosquitoes or 14,000 smaller bugs per day. That's about 240,000 mosquitoes a season per bird! Why have to rely on a noisy bug zapper or retreat to a screened-in porch in the evening when the purple martin can clean up those bugs and entertain you at the same time. There is nothing better than relaxing on the waterfront, watching a colony of martins clean up a cloud of bugs.
Setting up a martin system involves a bit of work if you choose to build and maintain a wooden house, or some initial expense if you decide on an aluminum house. However, you will find that the martins are well worth the time and money.
The best bet for the martins and for you--the host--is to buy an aluminum nesting house. Aluminum houses are lightweight, making them easier to take down.
My eight-compartment wooden house weighs a ton, and my fourteen-compartment wooden house requires two men to take it down. An aluminum house can be mounted on a telescoping pole which provides safe vertical access for cleaning out unwanted English sparrow nests.
Access to the compartments with some models is easy because the compartments can be individually opened. This can be done without disturbing existing martin nests. Once the house is raised back up, the martins will return without any apparent objections. Sparrows, (and, in wooden houses, starlings) should be discouraged because of the limited purple martin housing available, and because both species are likely to carry mites and other parasites which could spread to neighboring compartments, driving the young martins from their nests before they are ready to leave. It is said that starlings won't even nest in aluminum houses.
Aluminum houses never need painting and provide a cooler environment for the young martins. The openings are keyhole shaped, allowing better access to the nest for the adults, and have railings to help keep the young from falling from the house before they are ready to fly.
Purple martins are social birds and prefer to live in a colony. Therefore, houses made from wood should have at least six compartments. The compartments should measure 6" x 6" x 6", with an outside opening of 2 1/8 inches. The distance from the opening to the floor should be about one inch. The house should allow for adequate ventilation and drainage. Because wood surfaces can harbor mites, compartments should be cleaned annually. Sulphur (available at most drug stores), sprinkled in the compartment will kill any mites that the martins may bring with them. Ivory soap or Vaseline smeared on the inside ceilings will keep wasps away. Starlings are said to dislike clean, bright nesting sites, and can be discouraged by keeping wooden houses properly painted white.
The house should be mounted in an area with at least 15- to 25- foot clearance from the nearest trees or other obstructions. For best results, the pole should be from 12 to 15 feet high.
Until a colony is established, it is best to put the house up about the first of April. Sparrows and starlings will try to use the house, and can be discouraged by removing their nests. These nests, which consist of twigs and trash, are large and tend to overflow the compartment. The martins' nest is low and compact, and has a rim of mud on the edge by the exit hole.
My neighbor and I like to put one house up in early April, when the first scouts appear. We put our other three houses up around May 1, when most martins tend to arrive. This enables the scouts to know that their colony is still available, but reduces the nesting activities of the starlings and sparrows.
I've found the purple martin to be a very clean bird. They will carry their waste sacs a good distance away from the house site. Their song is delightful to listen to, and you'll find it very relaxing and interesting to watch them soaring after bugs or dipping down low over the water for a drink. You'll find yourself eagerly awaiting their arrival in the spring, and it's always a sad day in August when they once again head south for Brazil.
For further reading, try J. L. Wade's book, Purple Martin--America's Most Wanted Bird.
Reprinted (with minor modifications) from The Oneida Lake Bulletin: Spring, 1990.