Description The genus name of the purple martin, Progne, is from the Greek word Prokne, daughter of Pandion. The legend goes that she was changed into a swallow, a member of the bird family that includes the purple martin. The species name, subis, was used by Roman naturalist Pliny. It is Latin for "a bird that breaks eagle's eggs." Other names for the purple martin are the gourd martin, western martin, house martin, and black martin. The purple martin, about 7 to 8 inches (18-21 cm) in length and roughly the size of a bluebird, with a wingspan of 15 to 16 inches (39-42 cm), is the largest member of the swallow family. Adult males are a dark steel-blue, while females and immature males have a duller color above and are pale gray below.

Distribution  The purple martin is generally found in the eastern part of the state during the summer, though it has been known to breed as far west in South Dakota as Martin and Thunder Hawk. Though the purple martin was once common to the Black Hills, only a few are seen in that area now, and only during the spring migration.

Natural History
 

Purple martins are migratory birds. They winter in South America and migrate back to North America in January and February. Starting in Florida, purple martins move northward as the food supply of insects increases. In South Dakota the purple martins start arriving in April and May, with the greatest number reaching the state in the last week of May. There have been instances of early arrivals in late March, but the chances of cold, wet weather in a South Dakota spring greatly reduce the likelihood of the birds' surviving that early in the year. The last week of August is when the martins start migrating south. There have been reports of birds seen as late as late October in South Dakota.

What makes the purple martin an interesting bird are its diet and where it nests. A figure often associated with the purple martin is that one bird can eat 2,000 mosquitoes per day. This makes the purple martin desirable as a natural way to control mosquitoes. Purple martins eat mostly insects, which they generally catch in flight. Purple martins are also fond of eggshells that provide them with calcium. This behavior may be the source of its Latin species name. In the wild, martins nest in natural tree cavities, among rocks, in cliff holes, and in abandoned woodpecker holes. The purple martin will readily nest in rtificial houses. In fact, whether martins nest in an area is largely determined by the availability of martin houses. Martins will nest in hanging gourds, one-room boxes on top of poles, or in multi-room apartment boxes. These apartments range in size from 10 to 200 rooms. Females tend to choose a male who has occupied a suitable nesting site. Both sexes gather nesting material, but only the female incubates the eggs. The male does, however, guard the nest site in her absence. The eggs are white, usually 4 to 5 in number. The incubation time is 15 to 16 days. Both sexes feed the new hatchlings who spend 27 to 35 days in the nest.
Like may other species, these birds will return to nest in the same place where they were hatched.

Conservation Measures
 

All migratory songbirds are protected by federal law. It is illegal to harm the birds or disturb their nests. Certainly it would be foolish to hurt this species, which helps us so much by eating large numbers of mosquitoes. In fact, many home owners provide large martin houses to attract these birds to their yards.

Bull, John and John Farrand Jr., 1977, The Audubon Society Field Guide to North American Birds Eastern Region, Alfred K. Knopf: New York.
Johnsgard, Paul A., 1979, Birds of the Great Plains Breeding Species and Their Distribution, University
of Nebraska Press: Lincoln and London.
SDOU, 1991, The Birds of South Dakota, NSU Press: Aberdeen, SD 57401.
Terres, John K., 1980, The Audubon Society Encyclopedia of North American Birds, Alfred
A. Knopf: New York.
Wade, J. L., 1966, What you should not know about the Purple Martin, J.L. Wade: Griggsville, Ill.

Internet pages with information on martins and building martin houses:

http://www.purplemartins.com/Topics/housing.htm

http://free.woodworking-plans.org/purple-martin-house-plans.html

Written by:
John Neff, Pierre, South Dakota 57501. 1997.

Illustrated by:
Kathy Colavitti, independent artist, Green Bay, WI.

Reviewed by:
Dr. Dan Tallman, Northern State University, Aberdeen, SD 57401.

Publication of the Purple Martin fact sheet was funded by the South Dakota Department of Game, Fish and Parks, Division
of Wildlife, Pierre, SD.