Sand martin (Riparia riparia)
|Also known as:||bank swallow, collared sand martin, common sand martin, European sand martin, gorgeted sand martin|
|French:||Hirondelle de rivage|
|Size||Length: 12 - 14 cm (2)|
Wingspan: 25 - 29 cm (2)
|Weight||10 - 19.5 g (2) (3)|
The sand martin is classified as Least Concern (LC) on the IUCN Red List (1).
Also known as the bank swallow, the sand martin (Riparia riparia) is a small, slender bird with long wings, a slightly notched tail and a distinctive dark band across the breast (2) (3) (4) (5) (6). The male and female sand martin are similar in appearance (3) (4), with earth-brown or greyish-brown upperparts and a slightly darker tail and wings. The throat and underparts are white, and the contrasting brown chest band sometimes extends onto the centre of the belly (2) (3) (4) (5) (6) (7). The sand martin’s beak is small and black, and the legs and feet are blackish or dark brown (2) (4).
Juvenile sand martins have a buffy or cream wash on the belly, a reddish-brown to buffy wash on the face, neck, chin and breast, and pale edges on the feathers of the upperparts (2) (3) (4). Newly fledged juveniles also have a browner beak and browner legs than the adult (4).
The sand martin has a harsh, twittering song, and its calls have been described as a dry ‘drrt’, a harsh ‘tschr’ and a short ‘brrit’ (3) (4) (5) (6). The scientific name of this species, Riparia riparia, aptly describes its preference for nesting in riparian (riverside or streamside) banks (4).
Around three to eight subspecies of sand martin have been described, which vary in size, wing length, the darkness of the upperparts, and the distinctness of the breast band (3) (4). The subspecies Riparia riparia diluta is sometimes classified as a separated species, Riparia diluta, based on its paler, greyer plumage, indistinct breast band and slightly different vocalisations (3) (4).
The sand martin is one of the most widely distributed swallow species in the world (4), breeding across North America, Europe and Asia, as far south as Mexico, North Africa and southern Asia. Most sand martin populations migrate south in winter, with birds from North America travelling to Central America, South America and the West Indies, and those from Europe and Asia travelling to Africa, Arabia and southern Asia (3) (4). The subspecies Riparia riparia shelleyi, which breeds in Egypt, migrates only relatively short distances, to southern Sudan and northeast Ethiopia (3) (4).
During the breeding season, the sand martin is usually found near water. It feeds over wetlands, open water, grassland, farmland, or occasionally woodland, and breeds along coasts, rivers, streams, lakes, ponds or reservoirs. Nesting typically takes place in vertical, streamside cliffs or banks with crumbly, eroded soils, but the sand martin is also increasingly using man-made sites, such as sand and gravel quarries, road cuts, and even drainage holes in concrete banks (2) (3) (4) (5) (7) (8). Most breeding colonies are located in lowland areas (2) (3) (4).
On migration and during winter, the sand martin may use a variety of open habitats near water, including wetlands, marshes, prairies, savannas, seashore, mudflats, saltpans and agricultural areas (4). This species often roosts in reed beds (3).
The sand martin feeds almost exclusively on insects caught in flight, although it also occasionally takes insects and spiders from the ground or from the surface of water. Sand martins may feed alone or in large flocks, usually over water or open ground, and often associate with other swallow species. This species has a fast flight, with distinctive shallow, fluttery wing beats (2) (3) (4) (6) (8).
The breeding season of the sand martin runs between April and August (3) (4). It is a highly social species, nesting in colonies that may number from 10 to nearly 2,000 pairs. The sand martin nests in burrows, which are typically crowded together in a natural or artificial bank, usually in fairly loose soils that are easy to burrow into, and near large bodies of water that give plenty of flying space (2) (3) (4) (8). The burrows are mostly built in the upper part of the bank, to avoid ground predators (2) (4).
The male sand martins arrive on the breeding grounds before the females (3) and begin to excavate a burrow, using the beak, feet and wings to dig. When the burrow reaches about 30 centimetres in length, the male attempts to attract a female by singing and flying around the burrow entrance (2) (3) (4). Once the female has chosen a mate and nest site, both adults complete the burrow, which can reach up to a metre or more in length (3) (4) (8). Generally, a new burrow is dug each year, but old burrows may sometimes be enlarged and reused if they have not been lost through the erosion of the bank or cliff face (3) (4).
An enlarged nesting chamber is built at the end of the burrow, inside which the nest itself is placed. Both the male and female sand martin help construct the nest, which consists of a mat of grass, rootlets, leaves, twigs, straw and feathers. Around 2 to 7 white eggs are laid, and are incubated, mainly by the female, for 12 to 16 days (2) (3) (4) (8). The young sand martins are cared for by both adults and leave the nest at around 18 to 22 days old, after which the adults continue to feed them for up to a week (2) (3) (4). For the first four or five days, the young may return to the burrow at night, often to one that is not their own (3) (4). The adult sand martins are able to recognise their own chicks by their individual calls (4). As the breeding season comes to an end, the adults and young gather in large flocks, often with other swallow species, before departing on the southward migration (3) (4) (8).
In North America, the sand martin usually only raises one brood each season, but in other parts of its range it commonly raises two. Young sand martins may breed from their first year, and this species has been recorded living to at least nine years old (3) (4).
This common and widespread swallow species is not currently considered at risk of extinction (9). However, suitable sand martin breeding sites are localised and often temporary, sometimes being lost through natural erosion or flooding, or through human activities such as flood or erosion control and waterway management. Such activities can remove banks or make them otherwise unsuitable for nesting. In contrast, activities such as road-building and quarrying can provide the sand martin with new breeding sites, and this species will also nest in artificial burrows (2) (3) (4).
The sand martin population can be difficult to survey accurately, since the birds are concentrated at colonies that can change in size and location from year to year (2) (4). Its populations in North America generally appear to be stable (2) (3) (4) (8), but large-scale declines have been recorded in Europe in the past 50 years, mainly as a result of drought in the sand martin’s African wintering grounds (3) (4) (7). The use of pesticides on farms may also be a potential threat to the sand martin’s feeding habitats and food supply (3).
The sand martin is listed as a Threatened species in California, a Species of Special Concern in Kentucky and a Sensitive Species in Oregon, USA. It is also listed as a protected migratory bird in Canada and the USA (4). Conservation measures for this small swallow include the provision of artificial nesting tunnels and efforts to avoid disturbing nesting colonies in quarries. The listing of this species as Threatened in California has also protected some nest sites from proposed flood and erosion control projects, and a sand martin recovery plan is in place in this state (4).
Although the sand martin has been one of the most intensively studied swallows in the world, more information is still needed on its distribution, habitats and behaviour during winter and on migration. Further research is also needed into the populations and breeding habitats of some of the individual subspecies (4).
Find out more about the sand martin and its conservation:
BirdLife International - Sand martin:
The Cornell Lab of Ornithology: All About Birds - Bank swallow:
BBC Nature - Sand martin:
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- Incubate: to keep eggs warm so that development is possible.
- Riparian: relating to the banks of watercourses.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
IUCN Red List (March, 2011)
The Cornell Lab of Ornithology: All About Birds - Bank swallow (April, 2011)
- del Hoyo, J., Elliott, A. and Christie, D. (2004) Handbook of the Birds of the World. Volume 9: Cotingas to Pipits and Wagtails. Lynx Edicions, Barcelona.
Garrison, B.A. (1999) Bank swallow (Riparia riparia). In: Poole, A. (Ed.) The Birds of North America Online. Cornell Lab of Ornithology, Ithaca. Available at:
- Peterson, R.T., Mountfort, G. and Hollom, P.A.D. (1993) Collins Field Guide: Birds of Britain and Europe. HarperCollins Publishers, London.
- Ridgely, R.S. and Tudor, G. (1989) The Birds of South America: The Oscine Passerines. Volume I.University of Texas Press, Austin, Texas.
RSPB - Sand martin (March, 2011)
- Kaufman, K. (2001) Lives of North American Birds. Houghton Mifflin Harcourt, Boston, Massachusetts.
BirdLife International (March, 2011)