The Sand Martin (better known as the Bank Swallow to American birders) is a graceful and agile member of the swallow family. These gregarious migratory birds are most numerous along waterways where they nest in vertical eroded sand banks.
Appearance & Identification
What do Sand Martins look like?
The Sand Martin is a small member of the Swallow family with dark brown upperparts and a pale whitish throat and belly. Their most characteristic feature is a clear brown band across their chest, which may include a narrower vertical streak that extends to the belly.
These agile birds have sharply pointed wings and forked tails. Their short legs are greyish, and they have large black eyes and a short, straight black bill
Male and female Sand Martins look alike. Juvenile Martins are similar to adults but have a less clearly defined chest band with a pinkish or brownish throat. The brown feathers of their upperparts have buff or silvery edges, creating a slightly mottled effect.
Sand Martins are unlikely to be confused with any other species in the United Kingdom. However, American birders should compare them with the Northern Rough-winged Swallow and the juvenile Tree Swallow.
Sand Martin perching on the end of a branch
How big are Sand Martins?
Sand Martins are compact but graceful birds, noticeably smaller than the Swallow. They are the smallest member of the Swallow family in both the United Kingdom and the United States.
Sand Martins have a total body length of approximately 12 centimetres (4 ¾ inches).
They weigh just 10 – 18 grams (⅓ – ⅔ ounces), with females averaging slightly heavier.
These agile and fast-flying birds have a wingspan of 26 – 29 centimetres (9 – 11 inches).
Sand Martin (Bank Swallow) about to land on a plant
Calls & Sounds
What sound does a Sand Martin make?
The male Sand Martin produces a rapid twittering song when advertising his nest site and courting his partner. Females may also sing in aggressive encounters and during pair formation. These birds also make a harsh two-noted contact call and other simple vocalisations to express alarm and excitement.
Sand Martin calling from outside the nest
What do Sand Martins eat?
Sand Martins eat small flying insects. They occasionally take invertebrates from the ground or the water’s surface but generally catch their prey mid-air. The following types of insects are favoured:
What do Sand Martin chicks eat?
Sand Martin chicks eat small flying insects. They are fed by both parents, who work together to feed their young upwards of thirty times every hour. In order to feed the chicks more efficiently, adults will squeeze many insects into a single bolus (ball) and deliver it directly into the young bird’s mouth.
Sand Marin in-flight searching for food
Habitat & Distribution
What is the habitat of a Sand Martin?
Sand Martins are usually associated with freshwater environments like streams and lakes where erosion makes the vertical banks they need for nesting. However, they have adapted to use artificial walls created by quarrying and road construction, allowing them to expand into new habitats.
Away from the nest colony, Sand Martins forage over a variety of usually open habitats such as open water, wetlands, grasslands, pasture, and arable farmland. They avoid heavily wooded and mountainous environments.
What is the range of a Sand Martin?
The Sand Martin has an extensive global range on five of the world’s seven continents. These birds breed across most of the United Kingdom and Europe, North America, and temperate Asia in the summer. They occupy large parts of South America, Africa, and limited areas of Southeast Asia in the non-breeding season.
Where do Sand Martins live?
Sand Martins are most at home in the air and spend most of their time near the breeding colony during the nesting season, particularly when they have hungry mouths to feed.
These birds spend more than half their day flying over water bodies and adjacent areas in search of flying insects. They generally fly about 15 meters (50 ft) above the water or ground, although they may fly higher or lower depending on weather conditions and their prey.
Sand Martin (Bank Swallow) in-flight in natural habitat
How rare are Sand Martins?
Sand Martins are generally common in suitable habitats across their range. They are common summer visitors to the United Kingdom, although their numbers fluctuate depending on climatic conditions and food availability. According to the British Trust for Ornithology, there were approximately 71,000 Sand Martin nests in the UK in 2016.
Where can you see Sand Martins in North America?
Sand Martins (Bank Swallows) breed in suitable habitats across the northern half of the Lower 48 and much of Canada and Alaska. They can be seen almost anywhere in the South while on migration to and from their South American overwintering grounds.
Where can you see Sand Martins in the UK?
Sand Martins are widespread in the United Kingdom and Ireland, although localised in the south of England. Look out for these agile little birds flying along rivers and over nearby fields in the summer months, or search the skies near a local gravel pit or reservoir.
Sand Martin perching on a small branch
Lifespan & Predation
How long do Sand Martins live?
Sand Martins have a typical lifespan of about two years, although they can live for at least nine years in some cases.
What are the predators of Sand Martins?
Sand Martins are hunted by small birds of prey like the Sparrowhawk, Merlin, Hobby and American Kestrel. They are also vulnerable to nest predators like foxes, badgers, mink, and weasels.
Are Sand Martins protected?
Sand Martins are protected by the Wildlife and Countryside Act in the United Kingdom.
Are Sand Martins endangered?
Sand Martins are decreasing globally but remain common and extremely widespread. They are not endangered and have a green conservation status in the United Kingdom.
Sand Martin collecting nesting materials
Nesting & Breeding
Where do Sand Martins nest?
Sand Martins nest in colonies. They excavate burrows into vertical earth banks, usually along rivers but also at artificial sites like quarries. These burrows are usually half a meter to a meter (1.5 – 3 ft) deep.
Excavation usually takes less than a week, but they make slower progress in harder substrates. The adults then enlarge the end of the burrow to form a chamber and build a small platform nest of plant material and feathers. Sand Martin pairs may have a second brood but typically construct a new burrow to limit the risk of collapse and escape nest parasites.
When do Sand Martins nest?
Sand Martins nest in the spring and summer. They begin in March in the United Kingdom and lay their eggs in late May or early June.
They often produce a second brood before the breeding season ends in September. Nesting begins between mid-April and mid-May in the United States.
Sand Martin colony
What do Sand Martin eggs look like?
Sand Martins usually lay four or five eggs, although clutches of two to seven have been recorded. Their eggs are white and measure approximately 18 millimetres long and 13 millimetres (0.71 x 0.51 inches) wide.
Do Sand Martins mate for life?
Sand Martins form stable partnerships during the breeding season but probably find a new mate each year.
Pair of Sand Martins during the mating season
Sand Martin at nest hole with her young
Are Sand Martins aggressive?
Sand Martins are gregarious birds that nest in colonies. However, they are not afraid to fight to defend nest materials, nest sites, or their partner. In serious fights, they will grasp each other by the feet such that both birds fall from the air and continue to peck at their opponent on the ground.
Where do Sand Martins sleep at night?
Sand Martins roost in their nest tunnels until their chicks are approaching two weeks of age. Thereafter, they sleep nearby in other burrows or among the branches of trees, shrubs, or other vegetation. They may roost close together in bad weather or in enormous numbers (up to two million in some places) while on migration.
Sand Martin in nest tunnel
Do Sand Martins migrate?
Sand Martins are summer visitors to both the United Kingdom and the United States. They arrive in the UK in March and depart in September to overwinter in Africa south of the Sahara desert. North American birds overwinter in South America.
Are Sand Martins native to North America?
Bank Swallows, or Sand Martins as they are also known, are native to North America, including the Contiguous United States, Canada, and Alaska.
However, these migratory birds are only present for the summer breeding season.
Are Sand Martins native to the UK?
Sand Martins are native to the United Kingdom. They have been recorded on the British Isles for hundreds of years.