VOL. 18 (4) DECEMBER 1999 153 AUSTRALIAN WATCHER 1999, 18 , 153-159 First Record of a South Island Pied in Australia

by BO TOTTERMAN\ GREG CLANCY2 and ROBERT MOFFATT3

1Empire Vale, via Ballina, N.S.W 2478 2P.O. Box 63, Coutts Crossing, N.S.W 2460 3National Parks & Wildlife Service, P.O. Box 91, Alstonville, N.S.W 2477

Summary A single South Island Haematopus finschi was observed at Ballin a, New South Wales, between 6 November 1998 and 21 February 1999. This record was accepted by the Australia Rarities Committee, and is the first confirmed record for Australia. There have been several unconfirmed reports of the species from both Norfolk and Lord Howe Islands.

Introduction The South Island Pied Oystercatcher Haematopus finschi (SIPO) is endemic to New Zealand, where it is migratory, breeding mainly at inland sites on the South Island. Most birds migrate to the North Island in the non-breeding season, but some disperse only as far as the coast of the South Island, or south to Stewart Island (Marchant & Higgins 1993). There is only one accepted record outside New Zealand, a vagrant in Port Vila, Vanuatu, in 1983 (Hay 1985). Several other reports from outside New Zealand, including the Kermadec, Norfolk and Lord Howe Islands, are all unconfirmed, confusing, and appear not to have been precisely identified (Marchant & Higgins 1993, Carter 1998). This paper documents the continuing presence of a SIPO at South Ballina, N.S.W, first observed in November 1998, and present until February 1999. The record has been accepted by the Birds Australia Rarities Committee (case 258).

Discovery An unusual oystercatcher was observed roosting with an adult Pied Oystercatcher H. longirostris by BT at Robins Beach, South Ballina, New South Wales (28°56'S, 153°32'E), at 0740 h on 6 November 1998. It was observed only briefly with the intention of returning with other observers. It was noted as a possible hybrid Pied H. longirostris x H. fuliginosus. At 1500 h, the bird was observed foraging in the wash zone with an adult Pied Oystercatcher, close to the site of the earlier observation, by a banding crew from the New South Wales National Parks & Wildlife Service (N.PWS.), consisting of the authors and three additional observers, Brad Cheers, Gabrielle Holder and Simon Walsh. The conditions were fine, with a light to moderate wind, and good visibility. The habitat is a gently sloping sandy ocean beach, rising to low, grassed dunes. The beach is 21 kfn of uninterrupted sand, extending from the mouth of the Richmond River southwards to rock outcrops in the Broadwater National Park. It has a tidal range of less than 2m. From July to December, the northern 17 km of the beach is divided by Pied into breeding territories. The site where the unusual oystercatcher was observed is in a breeding territory of long standing, but which was vacant for unknown reasons in the 1998 breeding season. The bird was initially observed from a four-wheel-drive vehicle, and was later approached on foot to within about 30m for closer study and photography. TOTTERMAN, CLANCY & AUSTRALIAN 154 MOFFATT BIRD WATCHER

Notes were based on observations using 8 x binoculars and a Kowa 25 x telescope. Photographs were taken by GC, Brad Cheers and Simon Walsh. Both birds continued to forage while being watched for 20 minutes. All observers left the site to complete their banding activities, and returned about half an hour later. The unusual oystercatcher, still foraging as before, was induced to fly so that it could be observed and photographed when in flight. BT had initially n'lentioned the possibility of a hybrid or aberrant bird. In an ensuing discussion about its identity, RM suggested the likelihood of a New Zealand oystercatcher, and GC agreed with the possibility. None of the observers had any useful experience with all species of New Zealand oystercatchers, and it was agreed to consult the literature for independent conclusions. The consensus at a later meeting of the authors was that the bird was unquestionably a SIPO. To avoid additional disturbance to breeding Pied Oystercatchers with clutches and dependent chicks elsewhere on the beach, it was agreed to suppress publication of the observation. Details were released in a note in the Australasian Study Group newsletter Tattler in January 1999 (Straw 1999), after all the surviving chicks had fledged, and by press release by N.P.WS. in February.

Subsequent observations In order to obtain additional details of the plumage and bare parts, moult and behaviour, BTlater observed the SIPO on several occasions. Until early December it was seen alone, or together with between one and three Pied Oystercatchers, mostly near the original site, or a few kilometres farther north, towards the mouth of the Richmond River. On 12 December, BT observed the bird 10 km south of the original site, at Broadwater Beach in the Broadwater National Park, at a site that is regularly used by non-breeding Pied Oystercatchers during the breeding season. This site is interspersed with exposed rocks and backed by high dunes. The bird was roosting and foraging in a flock of 37 immature and non-breeding Pied Oystercatchers and one immature Sooty Oystercatcher. On 19 January 1999, BT and visiting observer Mike Carter studied and photographed the bird, which was roosting and foraging in the same flock that had moved northwards to one of the vacated breeding territories, and had been augmented by more Pied Oystercatchers. Carter, who has more experience with New Zealand oystercatchers than the authors, agreed with the identification. The bird was subsequently observed by numerous local, interstate and international ornithologists and bird-watchers. At the time of writing, it was last observed by BT on 21 February 1999.

Description Unless otherwise stated, this description of the SIPO is based on field notes by BT and GC, and photographs taken on 6 November 1998. The high number of references to Pied Oystercatcher are due to their constant and convenient presence for comparison.

General appearance and size The bird was a black-and-white oystercatcher of short and dumpy appearance, with very short legs and a very long, narrow bill (Plate 46). All the lines of VOL. 18 (4) First South Island Pied Oystercatcher DECEMBER 1999 in Australia 155

South Island Pied Oystercatcher (foreground) with Pied Oystercatcher, South Ballina, N.S.W., 6 November 1998. Note the generally dumpy appearance and the short legs Plate 46 Photo: Brad Cheers demarcation between different coloured plumage were sharp and distinct, without fuzzy edges. In flight, a long and wide white bar on the upperwing, an almost completely white underwing, and a triangle of white feathers extending well up the back were prominent features. The bird was approximately 10% smaller than a Pied Oystercatcher, when judged by silhouette area, and similarly small when viewed head-on in flight. It stood no more than two-thirds the height of a Pied Oystercatcher, because of its smaller body and very short legs. The tail appeared shorter than that of a Pied Oystercatcher and, in flight, the wing was also slightly shorter.

Bare parts The bill was both proportionally and actually longer than that of a Pied Oystercatcher. The length of the bill was estimated to be at least 1.6 times that of the head. It was of less depth at the base, less tapered and thinnty than that of a Pied Oystercatcher, and was slightly up-curved. Lateral compression extended well into the basal half, adding to the thin appearance. Bill colour was not noticeably different from that of adult Pied Oystercatchers, grading from bright orange at the base to a yellowish tip. The legs were of a thickness similar to those of a Pied Oystercatcher. The bird's most striking feature was its tibiae, which were very short and barely visible when the bird was at rest. The tarsi, also very short for an oystercatcher, were estimated as 20% shorter than those of a Pied Oystercatcher. Combined, the tibiae and tarsi were at least a third shorter, and many observers found this to be the best field character for separation from a Pied Oystercatcher. The colour of the TOTTERMAN, CLANCY & AUSTRALIAN 156 MOFFATT BIRD WATCHER legs was a dirty grey-pink, with a brownish tinge visible in certain light conditions. The colour changed gradually to a deeper pink-purple by March 1999, but was still not as bright as on an adult Pied Oystercatcher. The orbital-ring appeared to be thinner, and of a proportionally smaller outside diameter, than on a Pied Oystercatcher. It was just visible with the naked eye in bright sunlight, but in poor light was difficult to observe, even with binoculars. The colour was diffieult to define, but was dull and more brown than orange. It did not directly match the colour of any of the many juvenile and immature Pied Oystercatchers present. The iris was not noted with any confidence, and only recorded as being between orange and brown.

Plumage Upperbody Head, neck and mantle, black. Back, wholly white, appearing as a wedge between the black scapulars, extending from the rump. Rump and uppertail­ coverts, entirely white. Tail, black and sharply demarcated from the tail-coverts, superficially appearing as a terminal band. Because the tail-coverts were white, not black as on a Pied Oystercatcher, the black band was clearly narrower. The boundaries between black and white were all clear and sharp. Underbody Breast, black, with the remainder of the underparts white. The black plumage ended slightly higher up the breast than on most Pied Oystercatchers, with a sharp line of demarcation between the colours. Upperwing Black with a wide and conspicuous white bar, extending diagonally from the base of the trailing-edge of the innerwing, and ending abruptly at the outermost secondaries (Plate 47). What appeared as a very faint greyish extension was present in the two or three innermost primaries. Underwing All white except for a narrow black to dark-grey border of variable width (5-10 mm) along the leading- and trailing-edges, widest in the primaries. The basal portion of the trailing-edge lacked the black border, but there was an indistinct dark smudge at the base of the trailing-edge. In flight, the underwing appeared exceptionally white in comparison with that of a Pied Oystercatcher.

Call Calls were heard by BT when the bird was circling with a few agitated Pied Oystercatchers that had been attacked by a conspecific. The double-note calls appeared similar to those of the other oystercatchers, which were also calling. Visiting observers, including David Stewart (who recorded the calls), also heard the bird giving flight calls. None of the observers commented on any appreciable difference between the calls and those of Pied Oystercatchers.

Identification The size, length of the bill and legs, and distinctive plumage readily separated the bird from a Pied Oystercatcher, and indicated that it was a SIPO. There are only two other pied oystercatchers in the world with similarly short legs: the Chatham Island Oystercatcher H. chathamensis, and the East Asian subspecies osculans of the H. ostralegus. These are also the only two species with comparable plumage features, including the characteristic white dorsal triangle. VOL. 18 (4) First South Island Pied Oystercatcher DECEMBER 1999 in Australia 15 7

- South Island Pied Oystercatcher in flight, South Ballina, N.S.W., 6 November 1998. Note the white wing-bar, extending to the trailing-edge of the wing, and the wedge of white extending from the rump up the back Plate 47 Photo: Simon Walsh The Chatham Island Oystercatcher, although very short-legged and superficially similar to a SIPO, has an unusually thick bill and stout legs for an oystercatcher. Its plumage is rather similar, but has smudged borders between different-coloured plumage, and much more black on the underwing. It is a most unlikely visitor, with a small population endemic to the Chatham Islands, and never recorded elsewhere (Marchant & Higgins 1993). The Eurasian Oystercatcher may have tarsi as short as 45 mm (Hayman et a!. 1986), which overlaps with the range of those of the SIPO (42.9-52.3 mm) (Marchant & Higgins 1993). The eastern subspecies also has a very long but stout bill and, in most respects, similar plumage. However, the white bar on the upperwing is even more extensive and prominent than on the SIPO, being wider and extending outwards through the six innermost primaries. Moreover, in published photographs (Kanouchi et a!. 1998), the tibiae appear to be longer. The possibility of a hybrid between a Pied and a Sooty Oystercatcher was considered. Such hybrids are thought to exist, at least in Victoria (Collins et al. 1999), where they are pied but show many characteristics of Sooty Oystercatchers, and may have indistinct borders between the black and white plumage, similar to the pied form of the H unicolor (Mike Carter pers. comm. ). A hybrid was ruled out by the clearly demarcated black and white plumage. It has been suggested that a SIPO would be difficult to detect (Carter 1998), which may be true for a solitary bird or one hidden in a dense flock of other oystercatchers. Although some observers missed the bird altogether, most commented on how obviously different it was when compared with the nearby Pied Oystercatchers. When in flight, the plumage was also noticed as being easily recognisable. An observer with scant regard for bird-watchers, no experience with birds, and not briefed on what to look for, was brought in by BT as an experiment: TOTfERMAN, CLANCY & AUSTRALIAN 158 MOFFATT BIRD WATCHER he had no difficulty in separating the bird in a flock of 40 Pied Oystercatchers, and commented on the obvious difference in flight.

Ageing Our lack of experience with the species precludes us from making a precise estimate of age. Althpugh the bill was of adult coloration, the dull orbital-ring colour, possibly brown iris and, when the bird was first observed, the more grey than pink leg colour, point to an immature bird. In combination with the adult plumage, this suggests a sub-adult around 2-4 years old.

Behaviour From early November 1998, when the SIPO was first observed, until mid December, the bird remained in the vicinity of where it was originally found, where it was often observed roosting or foraging alone, or with one or two Pied Oystercatchers. When foraging, it was sometimes chased by the other birds. The principal prey of the local population of Pied Oystercatchers is a common small bivalve, the Pipi Donax deltoides (Owner 1997). Although the bird was observed consuming a small Pi pi on 6 November, it was not seen dislodging it, nor opening it. It appeared not to be very adept at catching Pipis, and spent much time foraging for small unidentified prey, by continuous deep probing. At times the bird was observed walking along the beach above the wash zone, turning over empty shells as though in search of intact Pipis. It was not observed dislodging, opening and consuming a Pi pi until13 December, when it had joined the flock of non-breeding birds. After joining the flock, the bird foraged with, and occasionally chased other birds. By late January 1999, its foraging technique was similar to that of the Pied Oystercatchers.

Discussion BT has been monitoring the local oystercatcher population closely for five years and, for the 12 months or so before the observation, had kept an especially close watch for possible hybrids. It is, therefore, unlikely that the bird had arrived in the area much earlier than documented and remained undetected. The presence of unusually large quantities of beach-washed kelp and a wreck of 83 Short-tailed Shearwaters Puffinus tenuirostris at the time of the first observation suggested preceding strong easterly winds offshore. This points to a recent arrival of the bird. However, November is well outside the SIPO migration season. The scenario of the bird having been elsewhere in mainland Australia, or on Lord Howe Island, must therefore also be considered possible. It is interesting to note that the SIPO has extended its range in New Zealand (Marchant & Higgins 1993), probably as a result of a large population increase, noticed as early as 1970 (Falla et a!. 1970). This has also led the species to use more often sandy beaches, which are not its typical habitat (A. Crocker in !itt.). As noted by Hay (1985), birds from rapidly growing populations are commonly found as vagrants far from their normal range; his record from Vanuatu, 2000 km from New Zealand, indicates that the SIPO is capable of very long flights, even allowing for intermediate islands being used as stepping stones. VOL. 18 (4) First South Island Pied Oystercatcher DECEMBER 1999 in Australia 159

The identity of the pied oystercatchers reported as vagrants or stragglers to Norfolk and Lord Howe Islands (McKean & Hindwood 1965, Hermes et al. 1986) has been subject to much confusion due to incomplete recording, variations in taxonomic status, and even loss of records (Anon. 1984, Carter 1998). This report is expected to generate more interest in those vagrants, aid in their possible re­ assessment, and hopefully result in more precise identification and reporting in the future.

Acknowledgements We wish to thank Tony Palliser and Mike Carter for constructive comments on a draft, help with reference material and use of their photographs. We also thank Mike Weston who acted as referee and John Peter for editing.

References Anon. (1984), 'Identity of Norfolk's Oystercatchers', Norfolk Nature Notes 1(1 ), 2. Carter, M (1998), 'SIPO or OZPO? South Island Pied Oystercatcher Haematopus finschi not Pied Oystercatcher H longirostris on Norfolk Island', Australian Birding 4( 4 ), 16-19. Collins, P., Jessop, R., Minton, C. & Graham, D. g999), 'A possible record of hybridisation between Pied Haematopus longirostris and Sooty ystercatchers H. fuliginosus at , Victoria',Aust. Bird Watcher 18, 160-163. Falla, R.A., Sibson, R.B. & Turbot!, E.G. (1970), A Field Guide to the Birds of New Zealand, Collins, London. Hay, J.R. (1985), 'An oystercatcher in Vanuatu', Notomis 32, 79-80. Hayman, P., Marchant, J. & Prater, T. (1986), Shorebirds: An Identification Guide to the of the World, Croom Helm, London. Hermes, N., Evans, 0. & Evans, B. (1986), 'Norfolk Island Birds: a Review 1985', Notomis 33, 141-149. Kanouchi, T., Abe, N. & Useda, H. (1998), Wild Birds ofJapan, Yama-Kei, Tokyo. Marchant, S. & Higgins, P.J. (Eds) (1993), Handbook of Australian, New Zealand & Antarctic Birds, vol. 3, Oxford University Press, Melbourne. McKean, J.L. & Hindwood, K.A. (1965), 'Additional notes on the birds of Lord Howe Island', Emu 64, 82. Owner, D. (1997), The Ecology and Management of the Pied Oystercatcher (Haematopus longirostris) in Nonhem NSW, B. App. Sci. Honours Major Thesis, Southern Cross University, Lismore. Straw, P. (1999), 'South Island Pied Oystercatcher: 1st Australian Record?', Tattler 18, 7. Received 31 May 1999 •