Birds

Martin

Progne and Delichon · also called martins

Least Concern ↓ insectivore Temperate grassland Rivers & wetlands Coasts & shorelines

A martin is the swallow family’s larger, chunkier cousin, and in eastern North America it has become almost entirely dependent on people. Purple martins there nest in nothing but the birdhouses and hollow gourds hung for them, a tradition stretching back to Indigenous communities centuries before European settlement, and today a whole hobbyist network keeps the population going.

Overview

Martins are large members of the swallow family, Hirundinidae — chiefly the purple martin (Progne subis) of the Americas and the house martin (Delichon urbicum) of Europe, Asia, and Africa. Both are aerial insect hunters, catching flies, beetles, and winged ants high above open country, farmland, and wetlands.

Housed by people

Eastern purple martins now nest almost exclusively in artificial housing — multi-compartment boxes or hollow gourds — a habit so entrenched that natural tree-cavity nesting is rare in that population. House martins build their own mud-pellet nest under eaves instead. Both nest colonially and gather in enormous communal roosts, sometimes over a million birds, before migration.

A managed population

Because eastern purple martins depend so heavily on maintained housing and on active control of competing house sparrows and starlings, their numbers are substantially sustained by a dedicated network of hobbyists and conservation groups — one of the clearest cases of a wild bird population kept going by organised human effort.

Status

Least Concern for both species, but declining in places — the house martin has fallen across parts of Europe with reduced flying-insect abundance and lost mud sources, and purple martin numbers depend on continued housing support.

Martin: common questions

What is the difference between a martin and a swallow?

Martin and swallow are both common names used within the same family, Hirundinidae, rather than marking a strict scientific division, and in general usage martin tends to be applied to the larger, often darker, less boldly patterned species, such as the purple martin and the house martin, while swallow is used for smaller, often more colourful species with longer tail streamers, such as the barn swallow. Some martins, including the purple martin, are close relatives of swallows classified in the same genus family as several birds called swallows, so the naming reflects tradition and appearance as much as any formal taxonomic boundary.

Why do purple martins nest almost only in birdhouses now?

The relationship goes back centuries, starting when Indigenous peoples in eastern North America hung hollowed gourds near their homes for martins to nest in, likely valuing the birds for pest control and for their loud, cheerful chatter, and the tradition was continued and expanded by European settlers with wooden and metal martin houses. Over many generations, eastern purple martins came to depend so heavily on this artificial housing, especially as natural tree cavities were lost to logging and land clearing and as competition from introduced house sparrows and starlings increased, that natural nesting in trees or cliffs is now rare in that population, making them unusually reliant on people actively maintaining suitable housing.

How can I attract martins to a birdhouse in my garden?

Success depends heavily on region and setup. Purple martins prefer a multi-compartment house or a cluster of hollow gourds mounted on a pole 4 to 6 metres high in a large, open area at least 12 metres from tall trees or buildings, since they need clear flight paths and dislike close cover, and a site with no active competing house sparrows or starlings does much better, as does proximity to an established colony, since martins are drawn to existing activity. House martins in Europe are more likely to build under house eaves given open mud sources nearby and are less particular about open flight paths, though they too benefit from nearby wetland or muddy ground for nest material.

Where do purple martins go for the winter?

The great majority of North American purple martins migrate to South America, concentrating heavily in the Amazon basin, particularly Brazil, where they gather in enormous nighttime roosts, sometimes with well over a million birds at a single site, before dispersing again in spring. The return migration follows a predictable pattern in which older, experienced males, known to martin enthusiasts as scouts, arrive back at established North American colony sites first, often by very early spring, followed later by females and by younger, first-time breeders.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published September 11, 2026. Last updated September 11, 2026.

Quick facts

Scientific name: Progne and Delichon
Diet: Almost entirely flying insects caught in mid-air, including flies, beetles, winged ants, dragonflies, and moths, hunted in fast, soaring, often high-altitude flight, with martins typically feeding higher above the ground than most smaller swallows
The largest North American swallow: The purple martin is the biggest swallow in North America, a chunky, glossy, dark blue-black bird noticeably larger than a barn swallow, with males a deep iridescent purple-black all over and females and young a duller grey-brown
A bird that moved into human housing: Eastern North American purple martins now nest almost exclusively in multi-compartment birdhouses and hollowed gourds put up specifically for them by people, a habit that began with Indigenous communities hanging hollow gourds for the birds centuries before European colonisation and has become so entrenched that natural tree-cavity nesting is now rare in the eastern population
A different kind of martin in Europe: The house martin of Europe, Asia, and North Africa is a separate, smaller species with a distinctive white rump, and unlike the purple martin it builds its own nest, a closed cup of mud pellets plastered under the eaves of buildings, cliffs, or bridges, often in colonies of many pairs
Colonial and highly social: Martins nest in colonies, sometimes numbering hundreds of pairs at a good site, and outside the breeding season they gather in immense communal roosts of tens of thousands to over a million birds, particularly before migration, choosing reedbeds, bridges, or specific trees night after night
A long-distance migrant: Purple martins winter mainly in the Amazon basin of South America, undertaking a round trip of many thousands of kilometres each year, and returning adult males, called scouts, typically arrive back at established colony sites earlier than females and younger birds, a pattern martin landlords track closely
A conservation partnership: Because eastern purple martins depend so heavily on artificial housing, their population is substantially maintained by a large, organised network of hobbyists and conservation groups who erect, monitor, and protect martin houses and actively control competing house sparrows and starlings, making the species one of the clearest examples of a bird sustained by dedicated human effort
Range: The Americas for the purple martin, breeding across most of the United States, southern Canada, and parts of Mexico and wintering mainly in the Amazon basin of South America, and Europe, North Africa, and temperate Asia for the house martin, breeding on buildings, cliffs, and bridges and wintering in sub-Saharan Africa, both species favouring open country, farmland, wetlands, and towns with access to standing or slow water for feeding and, in the house martin's case, mud for nest building.
Conservation status: Least Concern ↓ ≈ Martins as a group remain widespread, and the purple martin and house martin are both assessed as Least Concern, but both have shown concerning declines in parts of their range. The purple martin's eastern population is almost entirely dependent on maintained artificial housing and organised removal of competing house sparrows and starlings, and numbers can fall quickly if that support lapses, while western purple martins, which still nest more naturally in tree cavities and cliffs, face their own habitat pressures. The house martin has declined substantially across parts of Europe, likely linked to reduced flying insect abundance from agricultural intensification and pesticide use, the loss of muddy puddles needed for nest building, and pressures along its long migration route to and from sub-Saharan Africa in the wild