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Purple Martins Dependent
on Humans for Survival

Only one bird species in eastern North America is totally dependent on humans for its nesting sites — the Purple Martin (Progne subis). Through a centuries-long process known as a tradition shift, it has abandoned its ancestral ways of nesting in old woodpecker cavities. It now nests only in human-supplied houses and gourds placed in people’s yards. Native Americans started the process when they hung hollowed-out gourds to attract martins, giving the birds the distinction of having been managed by humans longer than any other bird species.

They are highly valued because of their insect eating ability and their melodious song. They are colonial cavity nesters using apartment style houses, hollowed out natural or long-lasting plastic gourds set closely together. To date, over one million North Americans put up housing for Purple Martins.

The Purple Martin is the largest of the swallows in North America, with adults roughly 7 1/2 inches in length. Adult males are dark purplish-black while adult females and yearling males are a lighter purplish-black on top of the head and back with a grayer breast and forehead. Each year they migrate between their wintering grounds in South America and nesting grounds in North America, a migration encompassing up to 8,000 miles.

Adult Purple Martins or "scouts" are the first to arrive back here in the spring and can be male or female. A good average arrival date in Alabama is March 1 and late February in the panhandle of Florida. You can be on the safe side by giving yourself a cushion and getting your housing prepared now.

Should your house or gourds still be in the same condition as when the martins flew south last summer, bring everything down to the ground and get rid of the spider webs and insects that may have taken over since the rightful tenants vacated and reinstall everything to full height. Sometimes the martin house/gourds will also require a fresh cover of white paint. The light color helps to reflect the hot Southern sun and also to highlight the entrance holes.

Most birds are repeats, but the majority of the first-year birds (usually last year’s youngsters) seek out a new residence, usually in the general area of their natal home site. This means that new 

martin house/gourds, especially if it is in the proximity of an active martin house, are likely to be used early on. Distant houses may not be found the first year but, eventually, you will have birds if placement parameters are followed.

The major reason people fail to attract martins is that they place their martin housing incorrectly, or their site is inappropriate martin habitat to begin with. Martins have very specific aerial space requirements. Housing should be placed in the center of the most open spot available, about 30-120 feet from human housing. Here in the Deep South, martins are less particular about house placement. Southern landlords can sometimes put housing within 15-20 feet of trees instead of the 40-60 feet required further north and still attract martins. Height of the housing can be anywhere from 10-20 feet. Keep tall bushes, shrubs and vines away from the pole. Do not attach wires to a martin house, especially if they lead to trees, buildings or to the ground. If your yard has too many trees near the martin housing, relocate the housing to a more open area, mount the housing higher or prune (or remove) trees to create a more open site. If you have a wooded lot, but live near a body of water, boat docks make ideal locations for mounting a martin house or gourd rack.

An established Purple Martin colony is likely to return year after year so long as you maintain the house and environment. They will consume millions of flying insects during the short time they are with us. And they will also provide us with their marvelous songs from long before dawn to throughout the day and evening. But by late summer they will leave our neighborhoods and begin their long southward migration to their wintering grounds in South America.

But rather than think about their departure, think first about their arrival. It is now time to prepare.

Martin houses and plastic gourds along with telescoping poles, which allow houses or gourds to be lowered vertically for cleaning and monitoring for English sparrows and starlings, are available at your local Co-op store.


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Date Last Updated January, 2006