in New Zealand

Brian Chudleigh and R. J. Chandler he European birder visiting New Zealand's North Island,* particularly Tduring the northern winter, will be struck by the number of Northern Hemisphere waders that are present. The variety of is also impressive, about 20 occurring in most winters, with occasional vagrants adding to the total.

*The publication of this paper has been timed to whet the appetites of birdwatchers who will be attending the XX International Ornithological Congress, in Christchurch, New Zealand, during 2nd-9th December 1990. EDS

continued...

416 [Brit. 83: 416-424, October 1990] Waders in New Zealand 417

The more common species include Pacific Golden Plover Pluvialis julva, Knot Calidris canutus, Red-necked Stint C. ruficollis, Sharp-tailed C. acuminata, Curlew Sandpiper C. ferruginea, Bar-tailed Godwit Limosa lapponica, and the ubiquitous Turnstone Armaria interpres. Less common species include Grey Plover P. squatarola, Black-tailed Godwit L. limosa and Hudsonian Godwit L. haemastica, Whimbrel Numenius phaeopus, Far Eastern Curlew N. madagascariensis, Greenshank nebularia, Xenus cinereus, Common Sandpiper hypoleucos, and Grey-tailed Tattler Heteroscelus brevipes. All these species have breeding ranges that include far- eastern USSR, so that to reach New Zealand they migrate more-or-less due south across or around the margins of the Pacific. Thus, the mix of Asiatic and more familiar 'European' species is explained; indeed, many of the latter are represented in New Zealand by their Asiatic races. We are fortunate to have a fine series of colour photographs of eight Holarctic species taken in New Zealand by Brian Chudleigh. They fall into two groups: four species common in Europe, though often of a different race from that occurring in Europe, and four species that are rare in Europe. In the text that follows, references to the seasons (and corresponding plumages), especially 'winter', apply to the situation in the Northern Hemisphere.

'European' species A species as familiar in New Zealand as it is in Europe is the Knot, which requires extensive intertidal mud-flats for feeding and occurs in large flocks. Counts suggest that up to 50,000 may spend the non-breeding season in New Zealand, most arriving by mid October and departing during March and April. These are birds of the race rogersi, which breeds in northeast Siberia and northern Alaska (Lane 1987), and apparently winters almost entirely in Australia and New Zealand. Its migration route to Australia is largely unknown, probably involving 'long-haul' flights, but ringing recoveries strongly suggest that the New Zealand birds move via the eastern side of Australia. Knots are present in New Zealand throughout the year, a few non-breeding individuals in grey winter-type plumage similar to that shown in plate 239 remaining during the Northern Hemisphere summer. By no means all breeding individuals acquire their brick-red breeding plumage before leaving New Zealand (plate 240). The upperpart feathers of rogersi in summer plumage are black with chestnut spots and fringes, unlike the corresponding feathers of the western European race islandica, which typically have yellowish fringes. Another feature of rogersi, shown well by both plates 239 and 240, is its relatively short bill. While these racial distinctions may be made with birds in summer plumage, the different races are probably indistinguishable in the field in both juvenile and winter plumages. Another common wader species is the Bar-tailed Godwit, with about 70,000 individuals in New Zealand during the northern winter, making it the most numerous Holarctic species to winter there. These are of the eastern race baueri, which breeds in northeastern USSR and also in 418 Waders in New Zealand

northern Alaska. It seems probable that they migrate directly over the western Pacific, since they frequently occur on Pacific islands at this time. The individuals shown here, plate 238, are males in fresh breeding plumage, on the early date of 22nd March. When seen on the ground, this race is very similar to (though slightly larger than) the western race lapponica. In flight, though, it is immediately distinguishable, since it is uniformly brown above, lacking lapponica % white rump and V up the back. The race baueri also has darker underwings, the coverts and axillaries being barred rather than largely off-white. Again, non-breeding indi­ viduals in winter-type plumage can be found in New Zealand year-around. In contrast to the relatively numerous Bar-tailed Godwits, compara­ tively few Whimbrels occur in New Zealand. These seem likely to be of the race variegatus, which breeds in northeastern USSR. They are very similar to the European race phaeopus, the differences being apparent in the field only in flight, when good views show that they have extensively barred underwing-coverts (plain, but off-white on phaeopus), and a tendency to a darker back and a more barred rump. Plate 246 shows a juvenile (which can be aged by its strongly marked, pale-notched tertials), its short bill suggesting that it is a male. The remaining wader species in the group familiar in Europe is the Curlew Sandpiper. Again, only small numbers reach New Zealand. Some of these attain breeding plumage before commencing northward migra­ tion; since the species is comparatively scarce in western Europe in spring, few of us will have had such stunning views as provided by the fresh- plumaged seen here (plate 243), roosting with Wrybills Anarhynchus frontalis, a New Zealand endemic.

'Asiatic' species The other four wader species are all rare in Britain, two being extremely so. Sharp-tailed , which breed in northern USSR, are common in Australia during the northern winter, though comparatively few reach New Zealand. Two photographs of this species (plates 241 and 242) are both instructive. Note that in plate 241 the birds lack the abrupt termination of streaked throat and breast against the unmarked belly characteristic of Pectoral Sandpiper C. melanotos, a species rare in both Australia and New Zealand. Plate 242 shows the dull, winter plumage, photographed in January. Plate 241 includes adults starting to acquire their summer plumage. The upperparts still lack the rufous fringes of the breeding adults, but one or two individuals already have a few of the neat, dark chevrons that mark the flanks and breast in summer. Terek Sandpipers, too, are rare in western Europe, since their breeding range barely reaches as far west as the Baltic; from there it extends east

238. Adult summer male Bar-tailed Godwits Limosa lapponica of the race baueri, New Zealand, March 1985 (Brian Chudleigh) 239. Adult winter Knot Calidris canutus of the race rogersi, New Zealand, April 1987 (Brian Chudleigh) 240. Adult summer Knot Calidris canutus of the race rogersi, New Zealand, April 1987 (Brian Chudleigh)

[The inclusion of plates 238-248 in colour has been subsidised by a donation from ZEISS West Germany]

241. Sharp-tailed Sandpipers Calidris acuminata in winter plumage, New Zealand, March 1983 (Brian Chudleigh)

242. Sharp-tailed Sandpiper Calidris acuminata (probably adult winter), New Zealand, January 1983 (Brian Chudleigh)

243. Adult Curlew Sandpiper Calidrisferruginea acquiring summer plumage, with Wrybills Anarhynchus frontalis, New Zealand, March 1986 (Brian Chudleigh) 244. Adult winter Terek Sandpiper Xenus cinereus, New Zealand, April 1984 (Brian Chudleigh) 245. Adult Grey-tailed Tattler Heteroscelus brevipes in fresh summer plumage, New Zealand, April 1984 (Brian Chudleigh)

Waders in New Zealand 423 through much of north-central USSR. The eastern portion of the population migrates southward around the western Pacific, with small numbers wintering in Australia and a scatter reaching New Zealand. The upturned bill and generally bright yellow legs of this species make identification relatively simple; the individual shown here (plate 244) has yet to develop the dark upper scapulars of the adult summer plumage; its bill is stained by feeding in a calcareous environment. The Grey-tailed Tattler is a major rarity in Europe, with only a single record (Brit. Birds 80: 540). In New Zealand, it occurs annually, in small numbers; it is quite common in Australia. The Grey-tailed Tattler breeds in far-eastern USSR, while the very similar H. incanus breeds in Alaska. Both species winter in the general Pacific area, though, as might be expected from their respective breeding localities, the Grey- tailed also has the more westerly distribution in the Southern Hemisphere in winter. Both species may, however, be encountered together, particu­ larly in eastern Australia. In the field, the differences between the two tattlers are subtle; both are grey Tringa-\ike waders with shortish chrome-yellow legs. Structurally, the folded wing of Wandering has a short primary extension beyond the tail, whereas on Grey-tailed the folded wing only reaches the tail tip. If it can be seen, the nasal groove of the Wandering Tattler is rather longer, appearing to extend more than halfway down the bill, while that of the Grey-tailed barely extends halfway. The best distinction is the call: 'weet- eet' in the case of Grey-tailed (recalling Ringed Plover Charadrius hiaticula to some ears), but a rapidly repeated, shrill 'peet' (a rapid, high-pitched version of the Whimbrel's call) from Wandering. The individual Grey-tailed Tattler featured here (plate 245) is an adult in breeding plumage, as shown by the barred underparts. In full plumage, the barring is less extensive than on Wandering, the Grey-tailed's belly always being white. Unfortunately, photographed against the light the nasal groove cannot be seen (though the nostril is clear enough), but the tips of the folded wings appear just to reach the tail tip, helping to confirm the identification. The final species, the Red-necked Stint, also a major rarity in Europe, is abundant in Australia, but is much less common in New Zealand. As a breeding species, it occurs in the High Arctic from about 110°E through to far-eastern USSR, with perhaps a few pairs breeding in western Alaska. Unlike the Little Stint C. minuta, which frequently breeds in its first summer, the Red-necked Stint typically does not do so, so that non- breeders may be found year-around in both Australia and New Zealand. The two photographs (plates 247 & 248) show both summer- and winter-plumaged individuals. The summer bird (plate 247), photographed

246. Juvenile Whimbrel Numenius phaeopus, probably a male of the race variegalus, New Zealand, October 1984 (Brian Chudleigh) 247. Adult Red-necked Stint Calxdris ruficoUis moulting from summer to winter plumage, New Zealand, November 1986 (Brian Chudleigh) 248. Adult Red-necked Stint Calidris ruficoUis moulting into winter plumage, New Zealand, August 1985 (Brian Chudleigh) 424 Waders in New Zealand in November, is rather worn and perhaps also faded, and this, together with the commencement of its moult to winter plumage, has rendered the fore-neck rather pale. The apparent winter-plumaged individual (plate 248), photographed in August, is in fact in active moult to its winter plumage. It retains traces of breeding-type plumage: a single red-fringed dark-centred lower scapular, and a few small worn dark feathers at the edge of the mantle. The winter scapulars are actively growing, and it can be seen that their feather bases have a sharp black central wedge. In full winter plumage, this dark area is usually largely covered by the broad grey tips of the overlying feathers, and so is not generally visible. Hence, it is usually suggested that a good recognition feature of winter Red-necked Stints is their clear grey upperparts and wing-coverts, showing only dark shaft-streaks. The black feather bases may, however, sometimes be seen, owing to the displacement or absence of overlying feathers.

Acknowledgments We are grateful to David Tomlinson for commenting on the text. Free use has also been made of Lane (1987) in summarising the status and movements of waders in the southwestern Pacific.

Reference LANE, B. A. 1987. Shorebirds in Australia. Melbourne.

Brian Chudleigh, 35 Levley Lane, Katikati, New Zealand Dr R. J. Chandler, 2 Rusland Avenue, Orpington, Kent BR6 SAU