Studies of less familiar 145. White-rumped or Little By I. J. Ferguson-Lees Photographs by F. G. H. Allen (Plates 33-34)

ON I 2TH JUNE 1967 a small swift with a white rump and a con• spicuous white throat was seen by Dr. J. T. R. Sharrock at Cape Clear Observatory, Co. Cork, and from the details noted seems likely to have been a White-rumped Swift affinis, an African and southern Asiatic species which is also Variously known as the , , Little African Swift and Indian Swift. If the record should prove acceptable to the editor of the Irish Bird Report and the Records Com• mittee of the British Ornithologists' Union it would be a significant addition to the British and Irish List—significant because this is a spreading species in north-west which was first found nesting in Europe in southern Spain in June 1966 (del Junco and Gonzalez 1966, Allen and Brudenell-Bruce 1967). Breeding has again been proved in two localities in southern Spain in the summer of 1967 and, if this species becomes permanently established in Europe, casual wanderers further north will be more likely occasionally to reach the British Isles. The account which follows may therefore be of value since the Field Guide (1966) was able to devote only three lines to this bird which was then defined as 'Accidental Italy, Malta'. There are a number of swifts with white rumps in various parts of the world, but most of them belong to the distinctive subfamily of spine-tailed swifts (Chaeturinae). Apart from A. affinis, there are three rather larger species of Apus which also have this feature—A. pacificus (known as the White-rumped Swift in eastern Asia and Australia), A. caffer (known as the White-rumped Swift in Africa) and A. horus (the of Africa). The first of these is of the same order of size as the European Swift A. apus and the other two are only a little smaller. Apart from diflferences in the size and shape of the rump patch and of the white throat patch, as well as the colour of the dark parts of the body, all three have a deeply forked tail. The much smaller A. affinis, which will be referred to as the White- rumped Swift throughout the rest of this text, has a square tail over an inch shorter than that of the European Swift. It is only three-quarters the size of the latter, being about five inches long compared with 6| 286 WHITE-RUMPED SWIFT STUDIES inches, and its wing span is some five inches smaller. The brief descrip­ tion in the Field Guide refers only to the white rump among plumage features, while Etchecopar and Hue (1967) have described it as 'entirely- black with a white rump', but this is rather misleading as it also has a variable but usually quite large and generally clear-cut white throat (plates 33 and 34), while the sooty-black upper-parts, brown under- parts and rather more slate-coloured wings all have a greenish sheen. This is more marked than in A. apus and differs from the glossy blue- black coloration of A. caffer and A. horus. The head is browner (as in most of these other swifts) and, particularly in the populations of north­ west Africa and the Middle East, the forehead is rather paler and greyer. The underwings have a pale leading edge strengthened by pale-edged coverts. In flight the wings look shorter and less pointed than those of A. apus and the action is slower and more fluttery. The trilling or churring calls are weak and high-pitched. Like other swifts, it feeds on small insects caught on the wing. Apart from its recent extension into southern Spain, this species breeds in north-west Africa (Morocco, Algeria, Tunisia and the Arguin Bank), in many parts of Africa south of the Sahara—south to Port Elizabeth (Ferguson 1955)—and in southern Asia from the Middle East across India and Ceylon to southern China, Malaysia, the Philip­ pines, Sumatra, Java and Borneo; throughout this range it is largely resident, but the north-west African and west Asian race galilejensis is partly migratory and apparently undertakes short journeys to warmer quarters in Africa and India (Vaurie 1959-65). Even so, Etchecopar and Hue referred to it as sedentary in Tunis, common in Morocco in December and January, and, though sometimes migratory, 'its ab­ sences do not last long and perhaps it merely wanders'. According to Brudenell-Bruce (195 8), the species was first reported at Rabat, Morocco, in 1925 and in the next 25 years it extended its breed­ ing range nearly 140 miles northwards to Tangier, becoming common there by 1953 and nesting along the main boulevards; Brudenell-Bruce added that 'it will be interesting to see whether it crosses the Straits to Spain in another few years' time'. Appropriately enough, it fell to him, in company with Commander John Agnew, to find the first nest in Spain in 1966. On the other hand, Brosset (1957) cited examples to show that populations which had colonised some towns in eastern Morocco had subsequently disappeared within a year or two and con­ cluded that this was a rather unstable species which was liable to colonise new areas and abandon them as rapidly. This is a highly gregarious species which often breeds in large colo­ nies, but small groups or single pairs can also be found. It occurs in a variety of habitats from open country to the middles of cities and builds its nest equally readily on cliffs or houses. In the last 30 years, and 287 BRITISH BIRDS particularly in the last 15 years or so, there has been an increasing tendency to nest on buildings, water towers and bridges in Rhodesia and this has contributed to a spread there (Brooke 1963). Nests may be under eaves, in crevices or on vertical walls and sometimes several are clustered together. They are usually loosely domed structures of straw, grasses, plant down, small twigs, feathers and even bits of paper cemented together with saliva. There is also an increasing tendency for this species to take over the disused nests of various . Brooke (1965) referred to the use of nests of Wire-tailed Swallows Hirundo smitbii and Cliff Swallows H, spilotkra in Africa, plate 33 shows the adapted nest of a pair of Pacific Swallows H. tahitha in Malaysia, and all the nests found so far in Spain have been in the nests of Red-rumped Swallows H. daurka as shown in plate 34. If the spread in Spain con­ tinues, therefore, the fact that it has been preceded by a rapid extension in the Iberian range of the Red-rumped (Ferguson-Lees 1963) —which has now also nested one or more times in south-west France, Sardinia, Corsica, Elba and Italy, all since 1963—may aid its own spread northwards. The following summary of records of this species in Spain, all in the Province of Cadiz, is based on the references given in the first para­ graph above and on subsequent information kindly supplied by F. G. H. Allen and P. G. C. Brudenell-Bruce {in litt.): 1962. North-east of Laguna de la Janda, a probable White-lumped Swift flying with Red-rumped Swallows on 9th August. 1964. Sierra de la Plata, east of Zahara de los Atunes and halfway between Barbate and Tarifa, up to three on several occasions in summer. Algeciras, one in May. 1965. Sierra de la Plata, up to three from 27th May to 28th September inclusive, but breeding not proved. 1966. Sierra de la Plata, first on 3rd May and up to four subsequently; nests then found on 1st, loth and 21st June, all occupied simultaneously, and a fourth with three hard-set eggs was destroyed by children on 10th July (all four were in Red-rumped Swallows' nests and a fifth contained noisy young thought to be White-rumped Swifts, though this was not proved); as many as eight over a feeding area a mile or two away during the summer; four last seen on 20th October. Los Barrios, some 40 miles east of the Sierra de la Plata, four or five on 1st June, one pair paying repeated visits to a deep and inaccessible overhang on a rocky outcrop; breeding regarded as virtually certain, but not proved. Benalud de Sidonia (formerly Casas Viejas), about 20 miles north of Sierra de la Plata, two with a dozen Red-rumped Swallows on 4th September. 1967. Sierra de la Plata, none seen in late and cold spring until 21st May, the first really hot day; subsequently three pairs found nesting in Red-rumped Swallows* nests. Los Barrios, two pairs on 27th June and one watched going in and out of a Red-rumped Swallows' nest. Several points are worth commenting on. First, the species seems clearly to be a summer-visitor to the south of Spain, arriving in May and leaving by October, but in Tangier, only 25 miles across the Straits, 288 WHITE-RUMPED SWIFT STUDIES individuals are likely to be seen throughout the winter; there appears to be no reason why it should not extend much further north as a summer-visitor. Secondly, Mr. Brudenell-Bruce informs me that in Tangier White-rumped Swifts used to be active round their nests from late March, exceptionally even in February, and by April were clearly breeding, whereas in Spain they have probably not laid until late May or early June. Thirdly, in Tangier they build their own nests or reoccupy those of the previous year without competition, but if they are breeding exclusively in Red-rumped Swallows' nests in Spain they often will not be able to take these over until the swallows have reared their young (many of which are on the wing in early June). On the other hand, one Red-rumped Swallows' nest which White-rumped Swifts had just begun to occupy in the Sierra de la Plata in late May 1967 had two or three recently broken eggs on the ground underneath; these were thought to be the Red-rumped Swallows' eggs ejected by the swifts. The first three nests in 1966 were in quite a small area, the second being 25 yards from the first and the third a further 100 yards away, but this is still very scattered by this species' usual gregarious stan­ dards. Mr. Allen writes: 'I had tried the first two nests with a hide, but the birds were shy and, rather than risk their deserting, I gave up the idea but managed to get just one single shot by walking up to the third nest and releasing the shutter as the bird dropped from it.' The original entrance to this nest was damaged and the swifts were therefore using a hole in the side of the funnel; afewfeathers can be seen sticking out of hole in the photograph (plate 34). In all the other cases the swifts have used the normal entrance. As one cannot see into a Red-rumped Swal­ low's nest without damaging it, it is difficult to be sure which species is in occupation unless the birds are actually seen leaving or entering. On the other hand, Mr. Brudenell-Bruce has found that, once the swifts have taken over a nest, a ring of white or grey down is visible (and sometimes very striking) round the entrance to the funnel. In most parts of Africa and southern Asia the clutch is usually of two or three eggs. A colony seen by Etchecopar and Hue at Fort Lamy, Chad, however, had nests with all numbers of eggs up to six, 'suggesting communal promiscuity'. This colony was unsynchronised and the nests held everything from fresh eggs to chicks ready to fly, but in another African colony studied by Moreau (1942) the first eggs were laid in 13 of the 17 nests within a space of ten days. The eggs, which are dull white and elongated like those of other swifts, are only slightly smaller than those of A., apus, with some overlap. The eggs of Red- rumped Swallows should usually be separable by their smaller size, different shape and shinier surface (only a few have reddish-brown spots and some clutches are no larger than those of the White-rumped Swift). Information on incubation and fledging periods seems to be lacking.

289 BRITISH BIRDS The localities in Spain where breeding has been proved have been given in this text only because they have already been published. As the nests are very vulnerable, however, it would perhaps be safer to suppress localities in future if the spread continues.

REFERENCES ALLEN, F. G. H., and BRUDENELL-BRUCE, P. G. C. (1967): "The White-tumped Swift Apus affinis in southern Spain'. Ibis, 109: 113-115. BROOKE, R. K. (1965): 'Little and Palm Swifts bleeding on man-made structures in Rhodesia'. Ostrich, 34: 27-35. BROSSET, A. (1957): 'Remarques sur le comportement du Martinet Apus affinis galihjensis (Antinori). Alauda, 25:150-151. BRUDENEIX-BRUCE, P. G. C. (1958): 'Notes on the birds of Tangier'. Mem. Soc. Sci, Nat. Maroc. N.S. Zoo/., no. 4: 1-46. DEL JUNCO, O., and GONZALEZ, B. (1966); 'Una nueva especie para la avifauna Europea: Apus affinis'. Ardeola, 12:5-9. ETCHECOPAR, R.-D., and HUE, F. (1967): The Birds of North Africa. London, pp. 357- 358. FERGUSON, W. T. (1955): 'Nesting and wintering of Indian Swift {Apus affinis) at Port Elizabeth'. Ostrich, 26:159-160. FERGUSON-LEES, I. J. (1963): 'Studies of less familiar birds: 125—Red-rumped Swallow'. Brit. Birds, 56: 416-418. MOREAU, R. E. (1942): 'Colktoptera affinis at the nest'. Ostrich, 13: 137-147. VAURIE, C. (1959-65): TheBirds of the Palearctic Fauna. London, Vol. 2, p. 649.

290 PLATE 33. White-rumped Swift Apus affinis nesting in old nest of Pacific Swallows Hirimdo lahitha, Malaya, July 1959—an interesting parallel to this species' use of nests of Red-rumped Swallows H. daiirka in Spain in 1966 and 1967 (pages 286- 290). Note the contrast between white throat and dark body (pbo/o: F. G. H. A.lhti) PLATE 34. White-rumped Swift Apus affinis leaving nest, Spain, June 1966. Note the white rump and throat, the light forehead and pale-edged under wing-coverts; the tail is unforked (pages 286-287). lts ex't from this former nest of Red-rumped Swallows was the hole in the side with feathers sticking out (pho/o: F. G. H. Allen)