A Record of the Siberian Blue Robin Larvivora Cyane at Ashmore Reef Off North-Western Australia, April 2012
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Australian Field Ornithology 2016, 33, 41–43 http://dx.doi.org/10.20938/afo33041043 A record of the Siberian Blue Robin Larvivora cyane at Ashmore Reef off north-western Australia, April 2012 Rohan H. Clarke1*, Mike Carter2, George Swann3 and Ashley Herrod1 1School of Biological Sciences, Monash University, Clayton VIC 3800, Australia 230 Canadian Bay Road, Mt Eliza VIC 3930, Australia 3Kimberley Birdwatching, P.O. Box 220, Broome WA 6725, Australia *Corresponding author. Email: [email protected] Abstract. An immature male Siberian Blue Robin Larvivora cyane was recorded on West Island, Ashmore Reef, off north- western Australia, on 23–25 April 2012. This is the first record of this species anywhere in Australia or its territories. Introduction limbs. Over the 3-day period of observation, the bird was always located within one of five clumps of Octopus Bush Ashmore Reef is an Australian Territory within the Timor on the western shore of the island. Sea at 12°20′S, 123°0′E, ~630 km north of Broome, The April 2012 survey at Ashmore Reef was exceptional 325 km off the Kimberley coast, Western Australia, and for the number of vagrant bird species of South-East 145 km south of the Indonesian island of Roti, south- Asian origin that were detected on West Island, including western Timor. It has four islands (West, Middle and East a Japanese Sparrowhawk Accipiter gularis on 28 April Islands and Splittgerber Cay), with a total land area of (BirdLife Australia Rarities Committee [BARC] Case No. 747: ~55 ha (Clarke et al. 2011). West Island is the most accepted), a Siberian Thrush Geokichla sibirica on vegetated of these and has numerous clumps of Octopus 18–23 April (BARC Case No. 798: accepted) and Bush Heliotropium foertherianum fringing it just inland of the observations, yet to be appraised by BARC, of a flock of shoreline. In April 2012, the four authors were members of 6 Oriental Honey Buzzards Pernis ptilorynchus that flew in a survey team conducting seabird and shorebird research to roost at dusk on 18 April and departed next morning, and in the region. The team was ashore on West Island once a single Eastern Crowned Warbler Phylloscopus coronatus on 18 April and then two or three times per day for the and a single Asian Stubtail Urosphena squameiceps, both period 19–27 April before the final landing on the morning during the period 23–25 April. of 28 April. As a small tropical depression formed near Ashmore Reef during our visit, weather conditions were variable and generally unsettled, with moderate-to-strong Description winds (of variable direction) and heavy tropical downpours on several days. Size and structure The bird was a small passerine judged to be slightly shorter in length (perhaps 1–2 cm shorter) than a bronze-cuckoo Observations Chrysococcyx sp. (one of the commonest birds available for comparison). In structure, it resembled a small short- In the late afternoon on 23 April 2012, RHC found an necked thrush, with a plump full breast and belly, and tail immature male Siberian Blue Robin Larvivora cyane of medium length. The head was small with a noticeably moving about in low cover under the tallest isolated clump of flattened crown and large rounded eyes. The bill was much Octopus Bush on West Island. It was instantly identifiable, finer than in a Turdus thrush (e.g. Common Blackbird and the other team members were quickly informed of its T. merula), with narrower, straighter edges and a sharply presence. It was observed intermittently for the remainder pointed tip reminiscent of many Australian warblers of the afternoon and during morning and afternoon shore (Acanthizidae). The tarsi were long and fine whereas the visits on each of 24 and 25 April. It was not seen after visible tibiae were short, projecting only just beyond the 25 April despite a further five shore visits, and was feathering of the belly on the perched bird. presumed to have left West Island that night. Although some very good views of the perched bird were Plumage and bare parts obtained, generally it kept low within dense cover, moved Most of the upperparts including the crown, mantle, back, frequently and was regularly lost from sight. During most rump, lesser and median primary-coverts, uppertail-coverts observations, it was alert and wary, moving away from and uppertail were royal blue, though in full sunlight some of observers, so that mostly it was viewed through a tangle of these feather-tracts appeared more grey-blue (Firgures 1–2). sticks, creepers and grass as it foraged on the far side of The throat, foreneck and upper breast were clean white. a shrub. After the initial find, the bird was often difficult to The blackish margin to the lower face (lores, malar region relocate. For example, on the morning of 24 April one of us and ear-coverts) continued onto the sides of the neck and sat quietly under the cover of the shrubs in which the bird upper breast to form a black border between the blue was originally detected for more than half an hour without upperparts and white underparts. Buff-brown flecking was a sighting before another observer arrived and located evident on the mid breast and lower breast. The lower the bird moving through a dense tangle of grass over low breast, belly, vent and undertail-coverts were variably 42 Australian Field Ornithology R.H. Clarke et al. Figure 1. Immature male Siberian Blue Robin, West Island, Figure 2. Immature male Siberian Blue Robin, West Island, Ashmore Reef, 23 April 2012. Photo: Rohan H. Clarke Ashmore Reef, 24 April 2012. Photo: Rohan H. Clarke mottled grey, off-white or buff. The primary-coverts, greater this species (van Duivendijk 2011). The bird would have coverts and alula were brown with faint-buff tips, as were hatched in the boreal spring–summer of 2011. the visible remiges in the closed wing; these provided a marked contrast with the adjacent blue upperparts. The bill was mostly dark grey to blackish with a paler flesh- Discussion coloured base to the lower mandible and evidence of a dull-yellow fleshy gape. The eyes were dark. The tarsi and This is the first sighting of a Siberian Blue Robin from feet were pale pink. anywhere in Australia or its territories (BARC Case No. 810: accepted). The species breeds across a vast area of Russia, extending into northern Mongolia, north-eastern Behaviour China, Korea and Japan (Collar et al. 2005). It winters The bird generally foraged on the ground under low across a broad range from extreme north-eastern India cover, and was wary and easily lost from view. It had a (rarely), continuously through much of South-East Asia distinct horizontal carriage and moved by hopping. When (Rasmussen & Anderton 2005; Robson 2008). Regular stationary, it routinely quivered its tail, especially when wintering grounds extend south through Peninsular perched. Although mostly remaining in cover, occasionally Malaysia (Wells 2007) and Borneo (Mann 2008; Myers it flew between isolated clumps of Octopus Bush (distance 2009). There are apparently very few records from Sumatra between bushes: 20–50 m). These flights were rapid and (van Marle & Voous 1988) and the first records from Java low to the ground, with a slightly undulating motion. The bird were obtained only in 1997 (Luijendijk & Scharringa 1999). was heard to call infrequently: an abrupt tack, presumably Farther east, in the Philippines, the Siberian Blue Robin in response to the observers’ presence. is a winter vagrant, known from just a handful of records (Dickinson et al. 1991), and there are no published records Identification for Wallacea (Coates & Bishop 1997). Despite the species’ apparent rarity or seeming absence in the region adjacent to the north of Ashmore Reef, it is a common migrant The bird was readily identified because it displayed many within the South-East Asian Flyway and has a history of of the features of an adult male Siberian Blue Robin, vagrancy elsewhere (e.g. western Europe including the including the blue upperparts, black face and sides of United Kingdom: Mullarney et al. 2001), so its occurrence breast and clean-white throat, foreneck and upper breast; off north-western Australia is not entirely unexpected. identification in the field was almost instant. There are no other species of this size and structure with a horizontal carriage and these plumage characters. This is supported Acknowledgements by field guide statements such as “male unmistakable” We are grateful to David Bishop for insight regarding the wintering (MacKinnon & Phillipps 2000, p. 319) and “unmistakably distribution of the species and assistance with references. Guy deep blue, black and white” (Brazil 2009, p. 416). Even Dutson and Richard Loyn provided helpful comments on a draft closely related species show gross male plumage of this paper. The skipper and crew of the MV Diversity II are differences that ensure identification is straightforward. For thanked for their professional conduct and assistance during example, the male of the closely related Indian Blue Robin this voyage. Permits to access Ashmore Reef were provided by Larvivora brunnea shows a bold white supercilium and an staff at the former Department of Sustainability, Environment, orange breast (Grimmett et al. 2011). Water, Population and Communities (now the Department of Environment). PTTEP Australasia funded the survey work that The blue dorsum extending from the crown to the rump, was being undertaken at the time of the discovery. the blackish face extending to the sides of the upper breast and the stark white throat and upper breast identify this individual as a male (Brazil 2009). The blue dorsum, but References retained juvenile rectrices, remiges and greater wing- Brazil, M.