The Purple Martin is the largest swallow in North America, and in the eastern United States it is almost completely dependent on human-made birdhouses for nest sites. This is perhaps the earliest spring migrant in Tennessee arriving by the first of March, and can be found nesting in every county in the state. After the breeding season in July and August, adults and fledglings form large communal roosts, often near large bodies of water, but also in urban and suburban settings where they can find sanctuary from predators. One roost in downtown Nashville discovered in 2010, contained tens of thousands of individuals (see Fun Facts below). Most Purple Martins in Tennessee depart by early September for the wintering grounds throughout the lowlands east of the Andes in South America.
Description: This large swallow has a large head, broad, pointed wings, and a short, slightly notched tail. The male is entirely bluish-black; the female is bluish-black on the back, dingy gray below with a darker chest and a gray collar on the neck. Juveniles are like the female but are paler on the belly, and dark gray-brown on the back.
Weight: 2 oz
Voice: The call is a collection of rich, liquid, gurgle notes, often given in flight.
- Other swallows are smaller and slimmer, and none have a dark belly.
- European Starlings have a similar shape in flight, but are not as buoyant, and have a long bill.
Habitat: Breeds near human settlements where birdhouses are provided, especially near water and large open areas (see links below). In winter, feeds in rainforest clearings and agricultural areas, and may roost in village plazas.
Diet: Flying insects
Nesting and reproduction: In eastern North America, Purple Martins have nested almost exclusively in nest boxes for more than 100 years. Historically they would have used natural cavities, especially old woodpecker holes, but now are found in multi-compartment birdhouses, hollowed-out gourds, and rarely cracks and crevices in buildings. European Starlings and House Sparrows often compete with Purple Martins for nest sites.
Clutch Size: Usually 3 to 6 eggs, with a range from 1 to 8.
Incubation: The female incubates the eggs for 15 to18 days.
Fledging: Both adults feed the nestlings, which fledge in 28 to 29 days. After fledging, adults and juveniles gather in large communal roosts, sometimes with thousands of individuals.
Nest: Eastern Purple Martins primarily nest in "martin houses" and gourds hung from poles. Both adults build the nest of twigs, plant stems, mud, and grass. Nest Box Instructions here.
Status in Tennessee: The distribution of Purple Martins in Tennessee is dependent on the location of artificial nest sites. They are a fairly common summer resident in towns, suburbs, and farmsteads across the state. Human management of colonies is often required because European Starlings and House Sparrows can out-compete martins for nest sites. Their population appears to be stable in Tennessee.
Dynamic map of Purple Martin eBird observations in Tennessee
- Native Americans started the practice of providing nest structures for martins. The Choctaw and Chickasaw Indians hung hollowed calabash gourds from saplings near their homes to serve as martin houses.
- Quote by John James Audubon (1831): "Almost every country tavern has a martin box on the upper part of its sign-board; and I have observed that the handsomer the box, the better does the inn generally prove to be."
- The Purple Martin not only gets all its food in flight, it gets all its water that way too. It skims the surface of a pond and scoops up the water with its lower bill.
- The oldest known Purple Martin in the wild was 13 years 9 months old.
- In mid-August 2010 an enormous Purple Martin roost site was discovered on the slope of Interstate 24 on the east side of Nashville near Oldham Street. Tens of thousands of martins form towering tornadoes of swirling birds and then "rain" into a 200-yard section of bushes. Video and more information on the roost will be posted on Tennessee Watchable Wildlife Facebook page
Obsolete English Names: western martin
Best places to see in Tennessee: Found in every county in the state. Starting in late July large numbers of martins can be seen congregating on the east side of downtown Nashville before going to roost at sunset.
For more information:
Tennessee's Woodworking for Wildlife page with nest box instructions
Purple Martin Conservation Association
The Purple Martin Society of North America
Brown, C. R. 1997. Purple Martin (Progne subis). The Birds of North America, No. 287 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
Nicholson, C. P. 1997. Atlas of Breeding Birds of Tennessee. Univ. of Tennessee Press, Knoxville.