Palearctic in Western Australia C. D. T. Minton and R. J. Chandler

ABSTRACT Together with Hong Kong (Brit. 86: 231-242), the northern shores of Western Australia provide an irresistible magnet for shorebird enthusiasts, with huge numbers of such as tenuirostris and Little Numenius minutus which are scarce on a World scale yet have occurred as vagrants to Western Europe. This paper, which briefly summarises the status of all species in NW Australia, is illustrated by photographs obtained on a special trip to the area.

The northern part of Western Australia (hereafter NW Australia) was 'discov­ ered' as an important area for waders in 1981, in the Royal Australasian Ornithologists' Union's Wader Census Programme. During this census, the whole of the 8,000-km coastline of northern Australia was covered by an aerial survey, with extensive follow-up on the ground to determine flock compositions. The greatest surprises of the survey were not only the absolute numbers of Palearctic waders (about 1.5 million), but also the fact that the area held many flocks of thousands of Great Knots*. This species was previously thought to be rare, with numbers possibly totalling only 5,000 worldwide. It is now known that during the Northern Hemisphere winter there are typically 320,000 Great Knots in Australia, with 180,000 of them in NW Australia. Many other species of Palearctic wader spend the non-breeding season in NW Australia; indeed, all the species occurring in the largest numbers are from the Palearctic. After Great Knot (plate 77), the most numerous are Bar-tailed

*Scientific names are given in table 1.

[Brit. Birds 89: 177-184, April 1996] © British Birds Ltd 1996 177 178 Minton & Chandler: Palearctic waders in Western Australia of the race bourn (plate 83), , Greater Sand (plate 81), , Red-necked (plate 84), Oriental , Curlew , Oriental Plover, Red-capped Plover, (plate 82), and Grey-tailed (plate 80). These are the 12 most numerous species, each occurring in numbers in excess of 10,000, of which only the Red-capped Plover is an Australian species. The numbers of the different wader species involved are sum­ marised in table 1.

Table 1. Minimum estimates of wader numbers in northern Western Australia. Non- Palearctic species (Australian endemics) are shown in square brackets. Data from Watkins (1993). Species (in order of importance) Numbers 1 Great Knot Calidris tenuirostris 180,000 2 Bar-tailed Godwit Limosa iapponica 100,000 3 Red Knot Calidris canutus 90,000 4 ieschenaultii 60,000 5 = Little Curlew Numenius minutus 50,000 5 = Red-necked Stint Calidris ruficollis 50,000 7 Glareola maldivarum 35,000 8 Calidris ferwginea 30,000 9 Oriental Plover Charadrius veredus 20,000 10 [Red-capped Plover Charadrius ruficapillus] 15,000 11 Terek Sandpiper Xenus cinereus 12,000 12 Grey-tailed Tattler Heteroscelus brevipes 11,000 13 Black-tailed Godwit Limosa limosa 8,000 14 Broad-billed Sandpiper Limicola falcinelius 6,000 15 Greenshank nebularia 5,000 16 = Grey Plover squatarola 3,000 16 = Ruddy Armaria interpres 3,000 18 = Sharp-tailed Sandpiper Calidris acuminata 2,000 18 = [Red-necked Recurvirostra novaeholiandiae] 2,000 18 = Charadrius mongolus 2,000 18 = SanderlingCa//c«sa/te 2,000 22 = Numenius madagascariensis 1,500 22 = Whimbrel Numenius phaeopus 1,500 24 [Pied Oystercateher Haemaiopus longirostris] 550 25 Tringa stagnatilis 500 26 Pluvialis fulva 250

TOTAL 690,300 Other Palearctic species occur in smaller numbers, including Broad-billed Sandpiper (plate 78), Sharp-tailed Sandpiper, Lesser Sand Plover (plate 79), Far Eastern Curlew, Pacific Golden Plover, Long-toed Stint Calidris subminuta, and Asian Limnodromus semipalmatus (Chandler 1995). The first four species occur in thousands, the remainder in lesser numbers. Altogether, 50 species of wader—almost one-quarter of the World's species—have been record­ ed in NW Australia. The main wader locations in NW Australia are Broome/Roebuck Plains, 80 Mile Beach and Port Hedland Saltworks, and these sites have been visited by 16 wader-study expeditions since 1981. Some of the expeditions were large Plates 77-84. Waders in Western Australia in March/April 1995 (R. J. Chandler). All are in adult summer plumage. The inclusion of these plates in colour has been subsidised by financial support from Carl Zeiss, sponsor of the British Birds Rarities Committee. 77. Great Knot Calidris tenuirostris, March 1995 (/?. J. Chandler) 78. Broad-billed Sandpiper LimicoJa falcinellus sibirica, April 1995 (R. J. Chandler) 79. Male Lesser Sand Plover Charadrius mongolus, April 1995 (R. J. Chandler) 80. Grey-tailed Tattler Heteroscelus brevipes, March 1995 (R. J. Chandler) 81. Male Greater Sand Plover Charadrius leschenaultii, March 1995 (R. J. Chandler) 82. Terek Sandpiper Xenus cinereus, March 1995 (R. J. Chandler) 83. Male Bar-tailed Godwit Limosa lapponica baueri, March 1995 (R. J. Chandler) 84. Red-necked Stint Calidris ruficollis, April 1995 (R. J. Chandler) British Birds, vol. 89, no. 4, April 1996 183

(25 people for two months), some small (five people for one week). These have included, at aE three main locations: 1. Ground and aerial surveys (additional to the now-standard summer and win­ ter monitoring counts of specified areas). 2. Ringing (cannon-netting and mist-netting), with a total of around 45,000 waders caught to date. 3. Migration-watching, using meteorological radar initially, and more recently by observing the departures on northward migration in March/April. Totals of 20,000-30,000 waders have been seen to depart each year from Broome alone. 4. Photographic studies.

Ringing and other studies Ringing recoveries show that, on northward migration, the Chinese coast is a key stopover site for almost every species of wader. The Shanghai area (Yangtse estuary and its adjacent shores) is especially important, with virtually all the Great Knots, Bar-tailed and Red Knots using that area. Weight gains of 50-80% are made by aE species before departure. There is much direct and indirect evidence that all but the smallest species fly non-stop direct from NW Australia to the Chinese coast, a distance of 5,500 km and a flight of three days' duration. On southward migration, the birds are more spread out than on northward migration, and Korea and Japan are important stopover sites. Curlew do a loop migration, with southbound recoveries mostly occurring well to the west of the northward route, with one recovery as far west as southern India.

The annual pattern Waders are present in good numbers throughout the year in NW Australia, with totals still in the thousands even during the Northern Hemisphere summer. This is because the one-year-olds of almost aE species do not migrate north until their second year, or not until their third, fourth, or even fifth year in the case of the larger waders. There is also a tendency for the resident Australian waders to flock during the Australian winter ('dry season' in northern Australia). For the wader enthusiast, perhaps the best time to visit is in March/April, when most waders are in breeding plumage prior to their northward departure. Some species, however, for example Far Eastern Curlew and Oriental Plover, mostly depart in early March, and the majority of several other species do so before the end of March, particularly Little Curlew and Oriental Pratincole. Wader numbers buEd up again from late August to October, as they return from the north, though arrivals start with Far Eastern in early August. At this time, many adults are still in breeding plumage; indeed, Grey , which are unlike most of the other species in migrating north while stiE in non- breeding plumage, are seen in Australia in breeding plumage only at this time.

The photographs The photographs (plates 77-84) show Palearctic waders in NW Australia during March/April. At this time, most individuals that are due to migrate to the Palearctic 184 Minton & Chandler: Palearctic waders in Western Australia have largely acquired breeding plumage, while there are also immatures in non- breeding plumage that will remain in Australia. Those species that use the coastal mudflats are most easily photographed at high-tide roosts, where a number of the accompanying photographs were taken. At the highest spring tides some species may use the rocks or low cliffs around , but at neap tides all species roost at the head of the beach. They range up the shore depending mainly on size of species: Far Eastern Curlews and Bar-tailed Godwits in or at the water's edge; Great and Red Knots just at the edge of the water, where Red-necked , Ruddy and often continue to feed amongst them, while Greater Sand Plovers are likely to congre­ gate in single-species groups well up the beach. The inland, freshwater wader species have to be photographed using wait-and- see techniques from a hide set up in favoured feeding areas. Those photographed in this manner included Broad-biUed Sandpiper and Lesser Sand Plover.

References CHANDLER, R. J. 1995. PhotoSpot: 36. . Brit, Birds 88: 362-364, plates 99 & 100. LANE, B. A. 1987. Shorebirds in Australia. Melbourne. WATKJNS, D. 1993. National Plan for Shorebird Conservation in Australia. Report to WWFA by AWSG.

Dr C. D. T. Minton, 165 Dalgetty Road, Beaumaris, VIC 3193, Australia Dr R. J Chandler, 2 Rusland Avenue, Orpington, Kent BR6 8AU

Appendix 1. Habitats Roebuck Bay, Broome, is a 25-km diameter bay just to the east of Broome, with vast tidal mud­ flats. There are high-tide roosts of 50,000 waders on the north-shore beaches, and of 100,000 waders at the rather inaccessible Bush Point area at the south entrance to the bay. The northern shores are highly accessible and have the light always behind the observer, which was one of the factors leading to the choice of the location for the Broome Observatory. Roebuck Plains is a 30 km X 20 km area of flatgrasslan d inland of Roebuck Bay. Up to 50,000 Little Curlews have been seen there, together with thousands of Oriental . 80 Mile Beach, which commences 200 km south of Broome and extends 150 km southwest towards Port Hedland, has mixed-species flocks dominated by Bar-tailed Godwits and Great Knots, with a density of up to 5,000 waders per kilometre. Port Hedland Saltworks was discovered in April 1982 by a wader team on its way from Perth to continue the wader studies which had commenced at Broome in August 1981. The section of the saltworks that is attractive to waders is situated some 30 km northwest of Port Hedland. An exceptional 6,000 Broad-billed Sandpipers was counted in March 1987, the World's largest known concentration of the species. It has also been a regular site for up to 140 Asian , and is a primary arrival area for Oriental Plovers, of which 30,000 were seen in November 1983.

Appendix 2. Birding in the Broome area Climate governs personal comfort in NW Australia. January-February is the main wet season, when it is very humid with up to 300-400 mm of rain, including the occasional cyclone. April to October is the dry season, with light rain perhaps on a couple of occasions in this seven-month period. It can still be hot (35°C) in April and October, but is exceptionally pleasant in the other months (25°-33°C, with cool nights) in the dry season. The initial contact point and best base is Broome Bird Observatory (address: PO Box 1313, Broome, WA 6725, Australia). Broome Bird Observatory was set up by the RAOU in 1988, and is wardened throughout the year. It provides catered and uncatered accommodation (partially air-conditioned), and camping and cooking facilities for visitors.