A Sighting of the House affinis from South-eastern Queensland

Two species of swift (Apodidae) are usually encountered in south-eastern Queensland, these being the White-throated Needletail caudacutus and the Fork-tailed Swift Apus pacificus (Roberts 1979, Blakers et al. 1984). The former is regarded as a common summer visitor to the region and the latter an uncommon summer visitor that is mainly recorded along the coast (Roberts 1979). In addition, occasional White­ romped Swiftlets Collocalia spodiopygius are known to stray into southern Queensland and adjacent parts of northern New South Wales (Blakers et a!. 1984). On the afternoon of I January 1994 at Caboolture near Brisbane, we observed a swift among a group of White-throated Needletails that was clearly not assignable to any of these three species. Our attention was first attracted to this party of swifts when we noticed that one member of the group appeared to have a pale ventral surface as it passed overhead. It was determined from further observation that this was probably caused by light reflected from the undersurface of an otherwise typical Needletail. The time was about 1830 h (E.S.T.) and the swifts were being viewed in strong, full light. These conditions allowed us to discern fine details of White-throated Needletail plumage, e.g. extent of ashy colour on back, white tertials when close and contrast between dark underwing coverts and undersurfaces of the primaries and secondaries from some angles. We also noted a number of reflective effects on their plumage, e.g. sheen, shadow and false colours. AUSTRALIAN 42 CZECHURA & CZECHURA WATCHER

After about 15-20 minutes of observation, we observed a particularly odd swift that was slowly circling among the group of Needletails. Our attention was drawn to its shape and the flight of the bird. The mystery bird was viewed for somewhere between three and five minutes in strong light, i.e. the sun was behind us and the bird was in the foreground some 40-60 m distant. The following features were noted. Size. Shorter in both body length and wingspan relative to adjacent Needletails. General impression was of bird about two-thirds the size of a Needletail in linear measurements. Wings. Curved and relative).y about as broad as for a Needletail but with a more rounded wingtip. Tail. Short with weak notch when folded. The notch tended to disappear when slightly fanned. At no time was the tail fully fanned while the bird was under observation. Proportions. For its size, the bird appeared to be quite robustly proportioned and very much gave the impression of being an over-sized martin sp. with longer wings. Colouration. Chin, throat and rump white and obvious at a distance. Otherwise dark grey with a bluish-grey bloom to plumage seen in full light as the bird banked away from us. Flight. Buoyant and slower than Needletails. Mainly observed in slow circling flight with wings outspread and tail partly fanned. Wing-beats shallower and less 'flicking' than Needletails. Overall impression. The bird in question seemed to combine aspects of both a swift and a martin. Otherwise it could be characterised as a small 'needletail' with round wingtips, white rump and throat and short notched tail. The mystery swift was not sighted again on this or subsequent days. On 8 January we were able to observe a mixed party of White-throated Needletails and Fork-tailed Swifts in the same area, although light conditions were not as good. This gave us the opportunity to compare the notes that we had taken on the unusual swift with the Fork-tailed Swifts. The mystery swift differed from them by its solid rather than slender build, broad rather than narrow wings, short notched not long and deeply forked tail, white rather than greyish throat, and slower style of flight. It was difficult to estimate size because we were comparing notes with direct observations. A further complication was the difference in build of the unknown bird relative to the Fork-tailed Swifts, but our subjective impression was that the two species were about the same size. These comparisons indicated that we had observed a species of swift or swiflet that was not one of those commonly encountered in this country. In our opinion the following features of the bird appeared especially significant: white chin, throat and rump; short and slightly notched tail; and generally stocky build. From subsequent literature searches, we found that the only swift or swiftlet possessing this combination of characters is the Apus affinis (Lekagul & Cronin 1974, King & Dickinson 1975, Smythies 1981, Wild Bird Society of Japan 1982, de Schauensee 1984, Beehler eta!. 1986, Pratt eta!. 1987). Further, the combination of swift and martin-like features of the Caboolture bird seemed important. King & Dickinson (1975) include Asian Palm Swift Cypsiurus batasiensis, White-eyed River-Martin Pseudochelidon sirintarae and Dusky Crag Martin Hirundo concolor among the species with which the House Swift may be confused in South-East Asia. Robertson (1980) commented on a superficial similarity of the specimen found at Darwin to the Tree Martin Hirundo nigricans. At present the House Swift has been recorded in Australia only from the Darwin area (Robertson 1980, Blakers et al. 1984), and so the present record would represent the first record of this swift from the east coast. The present sighting and those of unidentified swifts made elsewhere (Blakers et a!. 1984) clearly indicate the value of close inspection of individual swifts within flocks at all times. References Beehler, B.M., Pratt, T.K. & Zimmerman, D.A. (1986), ofNew Guinea, Princeton University Press, Princeton. VOL. 16 (1) MARCH 1995 House Swift in Queensland 43

Blakers, M., Davies, S.J.J.F., & Reilly, P.N. (1984), The Atlas of Australian Birds, RAOU & Melbourne University Press, Melbourne. de Schauensee, R.M. (1984), The Birds of China, Oxford University Press, Oxford. King, B. F. & Dickinson, E.C. (1975), A Field Guide to the Birds of South-East Asia, Houghton Millin, Boston. Lekagul, B. & Cronin, E.W. (1974), Bird Guide of Thailand, Kurusapa, Bangkok. Pratt, H.D., Bruner, P.L. & Berrett, D.G. (1987), A Field Guide to the Birds of Hawaii and the Tropical Pacific, Princeton University Press, Princeton. Roberts, G.J. (1979), The Birds of South-East Queensland, Queensland Conservation Council, Brisbane. Robertson, D.G. (1980), 'First record of the House Swift Apus a./finis (Apodidae) in Australia', Aust. Bird Watcher 8, 239-242. · Smythies, B. E. (1981), Birds of Borneo, Sabah Society, Kota Kinabalu. Wtld Bird Society of Japan (19~2), A Field Guide to the Birds ofJapan, Wild Bird Society of Japan, Tokyo. By GREGORY V. CZECHURA' and ROBIN E. CZECHURN 1Queensland Museum, P.O. Box 3300, South Brisbane, Queensland 4101 223 Webster Drive, Caboolture, Queensland 4510 Received 24 January 1994 •