These are small swallows with brown upperparts, paler underparts without a breast band, and a square tail with white patches.

They may be hunted by falcons and infected with mites and fleas, but their large ranges and populations mean that none of the crag martins are considered to be threatened, and all are classed as Least Concern on the IUCN Red List.

[2] The genus name is derived from the Greek ptuon (πτύον), "a fan", referring to the shape of the opened tail, and Procne (Πρόκνη), a mythological girl who was turned into a swallow.

DNA sequence studies suggest that there are three major groupings within the Hirundininae, broadly correlating with the type of nest built.

These martins are 12–15 cm (4.7–5.9 in) long with drab brown or grey plumage and a short square tail that has small white patches near the tips of all but the central and outermost pairs of feathers.

The Eurasian crag martin breeds from Iberia and northwesternmost Africa through southern Europe, the Persian Gulf and the Himalayas to southwestern and northeastern China.

Northern populations of the Eurasian crag martin are migratory, with European birds wintering in north Africa, Senegal, Ethiopia and the Nile Valley, and Asian breeders going to southern China, the Indian subcontinent and the Middle East.

[19] Some European birds stay north of the Mediterranean, and, like populations in warmer areas such as India, Turkey and Cyprus, just move to lower ground after breeding.

The dusky crag martin and rock are largely resident apart from local movements after breeding, when many birds descend to lower altitudes,[7] although some pale northern rock martins from North African and southern Arabian may winter further south alongside the local subspecies in Ethiopia, Mali and Mauritania.

[21] In South Asia, migrant Eurasian birds sometimes join with flocks of the dusky crag martin and roost communally on ledges of cliffs or buildings in winter.

The nest, built by both adults over several weeks, is made from several hundred mud pellets and lined with soft dry grass or sometimes feathers.

It may be a half-cup when constructed under an overhang on a vertical wall or cliff, or shaped as a bowl like that of the barn swallow when placed on a sheltered ledge.

When breeding, birds often fly back and forth along a rock face catching insects in their bills and usually feeding close to the nesting territory.

Crag martins exploit the area close to the cliff when they hunt, relying on their high manoeuvrability and ability to perform tight turns.

[38] Their large ranges and presumed high numbers mean that none of the crag martins are considered to be threatened, and all are classed as Least Concern on the IUCN Red List.