The Crag Martin's flight appears relatively slow for a swallow.

Crag Martin pairs nest alone or in small colonies, usually containing fewer than ten nests.

The remaining birds are now identified as Eurasian Crag Martin.

The Crag Martin has over the last few decades increasingly used houses and other man-made sites to nest.

The Dusky Crag Martin feeds mainly on insects caught in flight.

The Pale Crag Martin is smaller, paler and greyer than its southern relative.

The species differ in plumage shades and size, Eurasian Crag Martin being significantly larger than the others.

The white tail spots of the Eurasian Crag Martin are significantly larger than those of both its relatives.

Hyalomma marginatum is a hard-bodied tick found on birds including the Pale Crag Martin.

The Pale Crag Martin hunts along cliff faces for flying insects using a slow flight with much gliding.

The Crag Martin exploits the area close to the cliff when it hunts, relying on its high manoeuvrability and ability to perform tight turns.

Dusky Crag Martin pairs typically nest alone, although in suitable locations several pairs may be quite close to each other.

Ptilonyssus echinatus is a nasal mite found in birds including the Pale Crag Martin.

Pale Crag Martin pairs often nest alone, especially in the Sahara, although where suitable sites are available small loose colonies may form.

The Crag Martin builds a neat quarter-sphere nest lined with mud collected in its beaks, and lays 3-5 eggs.

The Eurasian Crag Martin may take aquatic species such as stoneflies, caddisflies and pond skaters.

These resemble the grey-brown Crag Martin (Ptyonoprogne rupestris) that is not rare in France.

Cf. also Pale Crag Martin and Plain Sand Martin.

The Eurasian Crag Martin builds a nest adherent to the rock under a cliff overhang or increasingly onto a man-made structure.

The Dusky Crag Martin (Ptyonoprogne concolor) is a small passerine bird in the swallow family.

Stone buildings such as old forts are particularly favoured, and the Dusky Crag Martin can be found in urban areas including Mumbai.

Smaller, paler and greyer than Crag Martin, and best distinguished by almost white throat and breast; no breast band.

It is 15% smaller, paler and greyer than the Eurasian Crag Martin, and has smaller tail spots.

The calls are similar to those of the Eurasian Crag Martin and include a soft chi, chi contact call and a twittering song.

The Crag Martin which has given its name to the Schwalbenwand ("Swallows' Wall") at Kreuzeck is frequently encountered.

The Ptyonoprogne species construct open mud nests and therefore belong to the last group.

The crag martins are four species of small passerine birds in the genus Ptyonoprogne of the swallow family.

The genus 'Ptyonoprogne' is often subsumed into the larger swallow genus 'Hirundo'.

The swallow genera Progne, Ptyonoprogne and Psalidoprocne derive their names from the myth.

These resemble the grey-brown Crag Martin (Ptyonoprogne rupestris) that is not rare in France.

The Dusky Crag Martin (Ptyonoprogne concolor) is a small passerine bird in the swallow family.

They were moved to the new genus Ptyonoprogne by German ornithologist Heinrich Gustav Reichenbach in 1850.

Other related genera named after the myth include the Crag Martins Ptyonoprogne, and Saw-wings Psalidoprocne.

Geyr von Schweppenburg named some subspecies of birds, including the Pale Crag Martin subspecies Ptyonoprogne obsoleta spatzi.

Conversely, if the Delichon house martins are considered to be a separate genus, as is normally the case, Cecropis, Petrochelidon and Ptyonoprogne should also be split off.

The three Ptyonoprogne species are members of the swallow family of birds, and are placed in the Hirundininae subfamily, which comprises all swallows and martins except the very distinctive river martins.

The Pale Crag Martin (Ptyonoprogne obsoleta) is a small passerine bird in the swallow family that is resident in northern Africa and in southwestern Asia east to Pakistan.

The small, pale northern subspecies of Crag Martin found in the mountains of North Africa and the Arabian peninsular is now usually split as the Pale Crag Martin, Ptyonoprogne obsoleta.

Even the smaller Ptyonoprogne species are slightly larger and more robust than the Sand Martin and Brown-throated Sand Martin, and have the white tail spots which are absent from the Riparia martins.

Where the ranges of Ptyonoprogne species overlap, the Eurasian Crag Martin is darker, browner and 15% larger than the Rock Martin, and larger and paler, particularly on its underparts, than the Dusky Crag Martin.

It is believed that the evolutionary sequence is from species that make open cup nests (Hirundo and Ptyonoprogne), through Delichon house martins with closed nests, to Cecropis and Petrochelidon, which have retort-like closed nests with an entrance tunnel.

The Rock Martin was formally described in 1842 as Hirundo fuligula by German physician, explorer and zoologist Martin Lichtenstein and was moved to the new genus Ptyonoprogne by German ornithologist Heinrich Gustav Reichenbach in 1850.

All three Ptyonoprogne crag martins are quite similar in behaviour to other Old World swallows that build mud nests, and are sometimes subsumed into the larger genus Hirundo, but this approach leads to inconsistencies in classifying other genera, particularly the house martins.

The Ptyonoprogne species construct an open mud nest and therefore belong to the last group; Hirundo species also build open nests, Delichon house martins have a closed nest, and the Cecropis and Petrochelidon swallows have retort-like closed nests with an entrance tunnel.

Ptyonoprogne is closely related to the larger swallow genus Hirundo into which it is often subsumed, but a DNA analysis showed that an enlarged Hirundo genus should logically contain all the mud-builder genera, including the Delichon house martins, a practice which few authorities follow.

The genus Ptyonoprogne is closely related to the larger swallow genus Hirundo, and is sometimes included within it since the nests of the Ptyonoprogne crag martins resemble those of typical Hirundo species like the Barn Swallow.

Although the nests of the Ptyonoprogne crag martins resembles those of typical Hirundo species like the Barn Swallow, the research showed that if Delichon, Cecropis and Petrochelidon are split from Hirundo, Ptyonoprogne should be also considered as a separate genus.