- 7.5–7.9 in
- 15.4–16.1 in
- 1.6–2.1 oz
- Smaller than an American Robin; larger than a Tree Swallow.
- Hirondelle noire (French)
- Golondrina grande negruzca, Golondrina azul americana (Spanish)
- Putting up martin houses used to be so common that John James Audubon used them to choose his lodgings for the night. In 1831, he remarked, “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.”
- Native Americans hung up empty gourds for the Purple Martin before Europeans arrived in North America. Purple Martins in eastern North America now nest almost exclusively in birdhouses, but those in the West use mostly natural cavities.
- European Starlings and House Sparrows often push Purple Martins out of local areas by taking over all of the nest sites, including houses that people put up specifically for the martins.
- Purple Martins roost together by the thousands in late summer, as soon as the chicks leave the nest. They form such dense gatherings that you can easily see them on weather radar. It’s particularly noticeable in the early morning as the birds leave their roosts for the day, and looks like an expanding donut on the radar map.
- Despite the term "scout" used for the first returning Purple Martins, the first arriving individuals are not checking out the area to make sure it is safe for the rest of the group. They are the older martins returning to areas where they nested before. Martins returning north to breed for their first time come back several weeks later. The earlier return of older individuals is a common occurrence in species of migratory birds.
- 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 Purple Martin Conservation Association supports the study of the Purple Martin and provides information on its website. The Purple Martin Society of North America also provides information on martins and martin houses.
- The oldest Purple Martin on record was at least 13 years, 9 months old, banded in 1933 and found in 1947.
Purple Martins forage over towns, cities, parks, open fields, dunes, streams, wet meadows, beaver ponds, and other open areas. In eastern North America they used to breed along forest edges and rivers, where dead snags offered woodpecker holes to nest in. But since humans began supplying nest boxes for them, eastern martins have become urbanites, living almost exclusively near cities and towns. In the West, martins have stuck with woodpecker holes in mountain forests or Pacific lowlands. Purple Martin wintering grounds are savannas and agricultural fields in Bolivia, Brazil, and elsewhere in South America. At night, wintering martins flock into cities and towns to roost, often in the trees of village plazas.
A year-round insectivore, the Purple Martin eats flying insects at altitudes higher than other swallows, often exceeding 150 feet and sometimes 500 feet or more off the ground. When they encounter prey, they turn suddenly sideways or upward, speed up, and then flare their tails as they trap the insect. Their menu includes beetles, flies, dragonflies, damselflies, leafhoppers, grasshoppers, crickets, butterflies, moths, wasps, bees, caddisflies, spiders, cicadas, termites, and mayflies. They feed during the day, rarely in groups but often in pairs (probably so the male can guard the female from mating with other males). Martins pick up small bits of gravel to help them digest insect exoskeletons.
- Clutch Size
- 3–6 eggs
- Number of Broods
- 1-2 broods
- Egg Length
- 0.8–1.1 in
- Egg Width
- 0.6–0.7 in
- Incubation Period
- 15–18 days
- Nestling Period
- 27–36 days
- Egg Description
- Pure white and smooth.
- Condition at Hatching
- Weak, with completely bare pink skin.
Nests in birdhouses, hole in tree, hole in cactus, or crevice in cliff or building. Nest made of twigs, plant stems, mud, and grass.
Both males and females visit several cavities before choosing a site (a female chooses her mate largely based on the nest site he occupies). The cavity is usually in a birdhouse, gourd, dead tree, saguaro cactus, building, or cliff, but sometimes in other structures like traffic lights, street lamps, dock pilings, or oil pumps. Birdhouses are variable but most are made of wood or aluminum, contain 8–12 rooms, and hang from wires or sit atop poles in open areas.
Purple Martins fly with quick flaps and glides, outlining big circles in the sky as they hunt insects. They rarely land on the ground except to collect nesting material and pick up grit to aid their digestion. Males defend small nesting (but not foraging) territories from other males and females do the same with other females. In eastern populations, each territory includes several compartments within a bird house (and occasionally several bird houses), but most birds gradually give up portions of their territory as more and more males arrive. The female usually defends a smaller territory, which usually shrinks down to the size of its own nest compartment by egg-laying time. Physical fights usually only break out if one bird goes into another bird’s nest compartment. Martins pair up with one male and one female per nest, but sometimes two females may settle into different compartments of one male’s territory. Both sexes frequently mate outside of their pair bond. Adults form flocks as soon as nestlings fledge, and congregate in large roosts throughout the winter.
Purple Martins are fairly common birds (especially in the Southeast), but their numbers declined by about half a percent per year between 1966 and 2010, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 7 million with 90 percent breeding in or migrating through the U.S., 7 percent in Mexico, and 3 percent breeding in Canada. They rate an 8 out of 20 on the Continental Concern Score and are not on the 2012 Watch List. Humans have helped counteract declines somewhat by putting up nest boxes, and people now provide virtually all nest sites for Purple Martins in the East. However, introduced species such as European Starlings and House Sparrows often take over martin houses and injure or kill eggs and nestlings. Purple Martins are also sensitive to cold snaps; bad weather kills more birds than all other sources of mortality combined. When unseasonably cold temperatures last more than three or four days, the birds starve for lack of insects. In the West, logging practices that remove dead trees can reduce nesting habitat for martins. Reduction of pesticide use on South American wintering grounds and protection of large winter roosts in Brazil is also important to the conservation of this species.
Long-distance migrant. Most Purple Martins that breed in eastern North American probably migrate across the Gulf of Mexico. They form huge roosts (of several hundred thousand birds) in late summer along the Gulf Coast from Texas to Florida. Others may fly over Mexico and through Central America. Purple Martins are probably leisurely migrants that fly only during the day and forage as they go. Nonetheless, they are one of the earliest South American migrants to arrive in the spring, reaching Florida as early as mid-January and New England in mid-April.
Put up a Purple Martin house in your backyard, and you just might be treated to a close-up look at these engaging birds all through the breeding season. You can put out crushed eggshells to give the martins a source of grit for digesting insect exoskeletons.
Find This Bird
In eastern North America during the summer, look for Purple Martins around martin houses, the miniature condominiums that many people put up in yards. The birds are more challenging to find in the West, where they nest in woodpecker holes in dead snags. Foraging Purple Martins hunt insects higher in the air than other swallows, but in the afternoon and evening they may feed low and close to nest sites. In late summer you might see enormous roosts of Purple Martins, particularly in the Southeast as they prepare to cross the Gulf of Mexico.
Purple Martins are a focal species in Project NestWatch. Learn more about them and contribute your data at their Purple Martin page.
House Sparrows and European Starlings are major competitors for martin nest boxes and can keep Purple Martins from breeding. Our Project NestWatch offers some suggestions for deterring these non-native species.
Our eBird project is a great way to keep track of the dates Purple Martins arrive and depart each year, and any other sightings in between.