The sand martin is brown above, white below with a narrow brown band on the breast; the bill is black, the legs brown. The young have rufous tips to the coverts and margins to the secondaries.
Its brown back, white throat, small size and quick jerky flight separate it at once from similar swallows, such as the common house martin (Delichon urbicum). Length: 12-14 cm. Weight: 10-18 g. Wingspan: 25-33 cm.
Distribution and Habitat
Sand Martin is a migratory passerine bird in the swallow family. It has a wide range in summer, embracing practically the whole of Europe and the Mediterranean countries and across the Palearctic to the Pacific Ocean. It is a Holarctic species also found in North America. It winters in eastern and southern Africa, South America, and the Indian Subcontinent.
The sand martin departs early, at any rate from its more northerly haunts. In August, the gatherings at the nightly roost increase enormously, though the advent and departure of passage birds causes great irregularity in numbers. They are essentially gone from their breeding range by the end of September.
Their food consists of small insects, mostly gnats and other flies whose early stages are aquatic.
The sand martin is sociable in its nesting habits; from a dozen to many hundred pairs will nest close together, according to available space. The nest is a horizontal hole in the vertical slope with an opening of 6-8 cm and a length of up to 1.5 m. Both birds dig it in shifts with the help of their legs. At its end is the socket chamber, which is a slight extension. In the nesting chamber is the nest itself, which is made up of straws, moss, dry grass, feathers and down. Four or five white eggs are laid about mid-late May, Both parents hatch for 13-15 days. The young leave the nest after about 3 weeks, the parents feed them with insects. Unlike other swallows, they usually raise only one hatchery per year.
This is not a rare bird, and it is classified as a species of least concern by the IUCN. It does have some local protections, as certain populations have declined or face threats from habitat loss and fragmentation. They are considered threatened in Bulgaria.