Rock martin

The rock martin (Ptyonoprogne fuligula) is a small passerine bird in the swallow family that is resident in central and southern Africa. It breeds mainly in the mountains, but also at lower altitudes, especially in rocky areas and around towns, and, unlike most swallows, it is often found far from water. It is 12–15 cm (4.7–5.9 in) long, with mainly brown plumage, paler-toned on the upper breast and underwing coverts, and with white 'windows' on the spread tail in flight. The sexes are similar in appearance, but juveniles have pale fringes to the upperparts and flight feathers. The former northern subspecies are smaller, paler, and whiter-throated than southern African forms, and are now usually split as a separate species, the pale crag martin. The rock martin hunts along cliff faces for flying insects using a slow flight with much gliding. Its call is a soft twitter. This martin builds a deep bowl nest on a sheltered horizontal surface, or a neat quarter-sphere against a vertical rock face or wall. The nest is constructed with mud pellets and lined with grass or feathers, and may be built on natural sites under cliff overhangs or on man-made structures such as buildings, dam walls, culverts and bridges. It is often reused for subsequent broods or in later years. This species is a solitary breeder, and is not gregarious, but small groups may breed close together in suitable locations. The two or three eggs of a typical clutch are white with brown and grey blotches, and are incubated by both adults for 16–19 days prior to hatching. Both parents then feed the chicks. Fledging takes another 22–24 days, but the young birds will return to the nest to roost for a few days after the first flight. This small martin is caught in flight by several fast, agile falcon species, such as hobbies, and it sometimes carries parasites, but it faces no major threats. Because of its range of nearly 10 million km2 (4 million sq mi) and large, apparently stable, population, it is not seen as vulnerable and is assessed as least concern on the IUCN Red List. 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. Its nearest relatives are the three other members of the genus, the pale crag martin, P. obsoleta of north Africa, the dusky crag martin P. concolor of southern Asia and the Eurasian crag martin P. rupestris. The genus name is derived from the Ancient 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. The specific name fuligula means 'sooty-throated', from Latin fuligo 'soot' and gula 'throat'. The three Ptyonoprogne species are members of the swallow family, and are placed in the subfamily Hirundininae, which comprises all swallows and martins except the very distinctive river martins. DNA sequence studies suggest that there are three major groupings within the Hirundininae, broadly correlating with the type of nest built. The groups are the 'core martins' including burrowing species like the sand martin, the 'nest-adopters', which are birds like the tree swallow that utilise natural cavities, and the 'mud nest builders'. The Ptyonoprogne species construct open mud nests 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. The genus Ptyonoprogne is closely related to the larger swallow genus, Hirundo, but a DNA analysis showed that a coherent enlarged Hirundo should contain all the mud-builder genera. Although the nests of the Ptyonoprogne crag martins resembles those of typical Hirundo species like the barn swallow, the DNA research suggested that 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. There are several subspecies differing in plumage shade or size, although the differences are clinal, and races interbreed where their ranges meet. The small, pale former subspecies (obsoleta, peroplasta, perpallida, presaharica, spatzi, arabica and buchanani) found in the mountains of North Africa, the Arabian peninsula and southwest Asia are now normally split as a separate species, the pale crag martin, following German ornithologist Jean Cabanis, who first formally described these birds, but the changes in size and colour are continuous, and the forms often intergrade where they meet, so the evidence for separate species is not strong. The southern forms of the rock martin can weigh more than twice as much as the smallest northern subspecies of pale crag martin. The average weight for P. f. fusciventris is 22.4 g (0.79 oz) against 10 g (0.35 oz) for P. o. obsoleta. The robust, large-billed southernmost forms (P. f. fuligula, P. f. pretoriae, and P. f. anderssoni) are sufficiently different from dark, fine-billed P. f. fusciventris that the latter could also be regarded as a potentially different species. However, Rhodesian ornithologist Michael Irwin collected specimens from southern Zimbabwe (then Rhodesia) which were dark above like P. f. fusciventris and rich reddish below like P. f. fuligula. This led him to suggest that the two groups had previously been isolated, but were probably hybridising following secondary contact. The rock martin of the nominate subspecies P. f. fuligula is 12–15 cm (4.7–5.9 in) long with earth-brown upperparts and a short square tail that has small white patches near the tips of all but the central and outermost pairs of feathers. It has a cinnamon chin, throat, upper breast and underwing coverts, with the rest of the underparts being a similar brown to the upperparts. The eyes are brown, the small bill is mainly black, and the legs are brownish-pink. The sexes are similar in appearance, but juveniles have pale edges to the upperparts and flight feathers. The other subspecies differ from the nominate form as detailed above.