Peregrine Falcon Falco Peregrinus of the Siberian Subspecies Calidus on Christmas Island

174 AUSTRALIAN FIELD ORNITHOLOGY 2010, 27, 174–176 Peregrine Falcon Falco peregrinus of the Siberian Subspecies calidus on Christmas Island MIKE CARTER1 and ANDREW SILCOCKS2 130 Canadian Bay Road, Mount Eliza, Victoria 3930 (Email: [email protected]) 2Birds Australia, Suite 2–05, 60 Leicester Street, Carlton, Victoria 3053 Summary This note records the occurrence of a Siberian Peregrine Falcon Falco peregrinus calidus on Christmas Island, Indian Ocean, in January 2010: apparently the second record for Australian territory of this migratory, Arctic subspecies. This is also the fifth record of a vagrant Peregrine Falcon on Christmas Island, although the others could not be identified to subspecies. Introduction On 5 January 2010, MC and AS saw a Peregrine Falcon Falco peregrinus of the Siberian subspecies calidus on Christmas Island, Australian territory in the Indian Ocean. At 0630 h we were standing in the car park in front of the clubhouse of the golf course, surveying the birds on the escarpment forming the amphitheatre on which the course is constructed. The morning was fine, cloudless and calm, and as we were looking due west, several Nankeen Kestrels F. cenchroides perched on vantage points on the cliff-face showed prominently their pale underparts, making them highly visible in the direct sunlight. One bird within the range of surrounding Kestrels appeared somewhat larger but otherwise similarly very pale. It was perched 500 m away on the highest rock on the ridge with just the blue sky as background, completely exposed, facing slightly to our left. Its identity could not be determined using binoculars, but viewed through a tripod-mounted Swarovski HDS 65 telescope with a 20–60× zoom eyepiece we immediately identified the bird as an adult Siberian Peregrine Falcon. We studied it through the telescope for several minutes before it took off, flying down and towards us in a steeply angled dive, before levelling out ~25 m above the ground when it disappeared behind trees. That course brought the bird to within 100 m of us, providing lateral and partly dorsal flight views. Although we were on the Island another 6 days and joined by other observers, the bird was not seen again. Description and identification Both authors are very familiar with this species. The shape was that of a typical Peregrine Falcon: broad shoulders when perched, broad-based swept-back pointed wings in flight, and with a short neck and short, square tail. Given that it was not overly large, it was probably a male. Overall, it appeared to be ~50% larger than a Nankeen Kestrel, this judgement based on bulk rather than linear dimensions. The clean, clearly demarcated plumage marked it as an adult. Viewed from the left, more front-on than in profile, the forehead, crown, nape and moustachial streak were very dark grey. The moustachial streak was well defined, narrow and rounded or square at the tip, set off by broad, very white cheeks, chin and throat. The upper breast was also white, as was the ground-colour of the lower breast VOL. 27 (4) DECEMBER 2010 Siberian Peregrine Falcon on Christmas Island 175 and belly. These areas had fine dark barring, very narrow and faint mid-breast, increasing in width and intensity down the belly but still leaving the impression of an overall pale ventral surface. General upperpart colour was seen only in flight, but appeared a shade of grey paler than the head. Subspecific identification as F.p. calidus is straightforward, as no other potentially occurring subspecies in this region (north-eastern Indian Ocean) has such a slender moustachial streak or such pale underparts (Ferguson-Lees & Christie 2001). F.p. tundrius is similar to calidus but as it is an American bird, remote from the region, it can be ignored. Texts that have a more local or regional coverage that also delineate these distinguishing characters include Cramp (1980), MacKinnon & Phillipps (1993), Coates & Bishop (1997), Grimmett et al. (1998) and Brazil (2009). In studies of raptors including Peregrine Falcons passing through Bali and Sulawesi, Germi & Waluyo (2006) and Germi et al. (2009) noted that the large and pale migratory subspecies calidus was clearly distinguishable from the smaller and darker resident F.p. ernesti. Moreover, it is this taxon that is most likely to occur as a vagrant on Christmas Island, as it is a long-distance migrant that breeds in far northern Asia, wintering regularly in the Greater Sundas (Cramp 1980; MacKinnon & Phillipps 1993; Coates & Bishop 1997; Ferguson-Lees & Christie 2001; Brazil 2009). Christmas Island is <400 km south of Java. Germi & Waluyo (2006) reported seeing seven calidus individuals on eastern Bali during the boreal autumn raptor migration heading east into Wallacea in 2005. On Sangihe, North Sulawesi, two were seen heading north in spring 2007 and 17 heading south in the autumn of that year (Germi et al. 2009). If the bird had not been adult or if the views were insufficient for certainty, then given the location, four other subspecies might be considered as contenders. The closest breeding Peregrine Falcons are in the Greater Sundas, where the subspecies F.p. ernesti is resident and largely sedentary (Ferguson-Lees & Christie 2001). This is the ‘darkest of all races, black above, while throat and chest washed rufous- buff and otherwise blue-grey below with dense black barring’ (Ferguson-Lees & Christie 2001, p. 917), thus easily eliminated. So too is the Australian subspecies F.p. macropus because it has a lobe-shaped moustachial streak, much broader and more rounded than in this individual (Marchant & Higgins 1993; Olsen et al. 1993; Ferguson-Lees & Christie 2001). The nominate subspecies has a range that includes much of Asia south of the tundra (Ferguson-Lees & Christie 2001), but adults differ from the Christmas Island bird in having broader moustaches and are cream-buff below (Beaman & Madge 1998; Mullarney et al. 2001). Although some individuals wander, that subspecies is not a true migrant. F.p. japonensis is not so easily discounted, as it is a migrant breeding in north-eastern Siberia south to northern Japan, wintering south to the Philippines and Borneo (Marchant & Higgins 1993). This subspecies is ‘more rusty-white below’ (Ferguson-Lees & Christie 2001, p. 917) and, judging from photographs, has broader moustaches (Kanouchi et al. 1998; Iozawa et al. 2000; Shimba 2007). Previous reports Subspecies calidus has probably been recorded once previously in Australian territory. An observation of a falcon seen on Ashmore Reef (Timor Sea) on 2 November 2003 was submitted to the Birds Australia Rarities Committee (Case no. 414) as a Eurasian Hobby F. subbuteo, but during the assessment process it was re-identified as a Peregrine Falcon, most likely subspecies calidus (Palliser 2007). AUSTRALIAN 176 CARTER & SILCOCKS FIELD ORNITHOLOGY Valenzuela & James (2006) stated that the Peregrine Falcon is a vagrant to Christmas Island, with only one record. However, before the date of that publication we know of two reports. Stokes (1988, p. 33) stated ‘Pearson (1966) records a juvenile present between February–April 1962’. Although we have not checked Pearson’s original publication in the Bulletin of the British Ornithologists Club, it would appear that no attempt was made to determine the subspecies. That record is also listed by Johnstone & Darnell (2004), where the original Pearson publication is cited. Peter Lansley, Rob Farnes, James Watson and Bill Watson saw this species on Christmas Island at four sites on three days between 28 December 1996 and 1 January 1997 (P. Lansley in litt. 17 January 2010). It was not identified to subspecies but, as this bird was also stated to be a juvenile, subspecific determination would be difficult at best. Lansley considers that it resembled Australian birds. We also know of a more recent sighting. In early January 2008, Dan and Beth Mantle (in litt. 19 January and 28 February 2010) saw one at Margaret Knoll but ‘it was too distant to make an assessment on the underpart colour and barring, underwing, malar stripe, crown colour etc.’, so subspecies could not be determined. It made an unsuccessful stoop at a Red-tailed Tropicbird Phaethon rubricauda, then continued to chase it for ~30 seconds. References Beaman, M. & Madge, S. (1998), The Handbook of Bird Identification for Europe and the Western Palearctic, Princeton University Press, Princeton, New Jersey. Brazil, M. (2009), Field Guide to the Birds of East Asia, Christopher Helm, London. Coates, B.J. & Bishop, K.D. (1997), A Guide to the Birds of Wallacea, Dove, Brisbane. Cramp, S. (Ed.) (1980), The Birds of the Western Palearctic, vol. 2, Oxford University Press, Oxford, UK. Ferguson-Lees, J. & Christie, D.A. (2001), Raptors of the World, Helm, London. Germi, F. & Waluyo, D. (2006), ‘Additional information on the autumn migration of raptors in east Bali, Indonesia,’ Forktail 22, 71–76. Germi, F., Young, G.S., Salim, A., Pangimangen, W. & Schellekens, M. (2009), ‘Over-ocean raptor migration in a monsoon regime: Spring and autumn 2007 on Sangihe, North Sulawesi, Indonesia,’ Forktail 25, 104–116. Grimmett, R., Inskipp, C. & Inskipp, T. (1998), Birds of the Indian Subcontinent, Helm, London. Iozawa, H., Yamagata, N. & Yoshino, T. (2000), Japanese Bird 550: Landbirds, Bunichi General Publisher, Tokyo [in Japanese]. Johnstone, R.E. & Darnell, J.C. (2004), ‘Annotated checklist of Christmas Island birds’, pp. 439–476, Appendix A in Johnstone R.E. & Storr, G.M., Handbook of Western Australian Birds, Vol. 2, Passerines, Western Australia Museum, Perth. Kanouchi, T., Abe, N. & Ueda, H. (1998), Wild Birds of Japan, Yama-Kei, Tokyo [in Japanese]. MacKinnon, J. & Phillipps, K. (1993), A Field Guide to the Birds of Borneo, Sumatra, Java and Bali, Oxford University Press, Oxford, UK. Marchant, S. & Higgins, P.J. (Eds) (1993), Handbook of Australian, New Zealand and Antarctic Birds, vol.

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