Wood Sandpiper Tringa glareola 林鷸
Category I. Common migrant and winter visitor to freshwater wetlands, with some evidence of a decline in numbers.
IDENTIFICATION
Apr. 2006, John and Jemi Holmes. Adult, breeding plumage.
19-23 cm. Small to medium-sized shorebird, similar to Green Sandpiper but distinguished by habitual occurrence in flocks, paler brown upperparts with larger pale spotting, paler and more diffuse chest colouration, diffuse supercilium behind eye and more yellowish legs.
Adult in breeding plumage has coarse whitish and buff marks on the upperparts.
Sep. 2022, Sarawak, Malaysia. Dave Bakewell. Juvenile.
Juvenile is neatly spotted above with paler underparts and finely-streaked breast.
Dec. 2004, John and Jemi Holmes. Adult, non-breeding plumage.
The adult winter is greyer with plainer chest and flanks.
Oct. 2022, Sarawak, Malaysia. Dave Bakewell.
Distinguished in flight from Green Sandpiper by narrow tail bars, paler brown upperparts with more whitish spots (and thus less uniform) and pale underwings
VOCALISATIONS
The typical flight call of flushed birds is a fairly loud and repeated ‘too’ or ‘tyee’.
When alert or agitated, the following double-note contact-alarm call may be given.
DISTRIBUTION & HABITAT PREFERENCE
Wood Sandpiper occurs in low-lying areas of freshwater and brackish marsh, wet agriculture, fish ponds, larger channelised watercourses and rice paddy throughout the New Territories, especially at such localities as Long Valley (where the highest count is 221), Kam Tin (190), and, previously, in the San Tin-Lok Ma Chau-Chau Tau area (300) and at the former airport at Kai Tak (164). It is also regularly recorded on Lantau and Po Toi, though numbers are generally low.
Especially during spring passage small numbers occur on the intertidal mudflats of Deep Bay, but this is not the preferred habitat, and it is very rarely seen there in winter.
OCCURRENCE
Wood Sandpiper is a common passage migrant and winter visitor, with highest numbers occurring in autumn. Figure 1 illustrates the pattern of occurrence at the wet agricultural fields of Long Valley, a favoured systematically-surveyed site.
Autumn passage is generally noted from the second week of July, earlier in some years. Main passage occurs from the second week of August to the end of October, peaking around the beginning of that month. The highest numbers occurred in 1998 and reached a peak of 1,221 on 10 September. Since that date, the highest count is 597 on 9 October 2006.
Winter numbers are relatively constant from the third week of November to mid-February, in which season the highest counts are 350 on 25 January 1992 and 200 on 24 January 1977 and 8 January 2007.
Spring passage commences in March, and numbers increase to a peak in the third week of April. The highest single-site spring counts are 450 on 12 April 1990 and 14 April 2002; a total of 452 were present at four sites on 14 April 1996. Numbers decline sharply at the end of April, and by the second week of May Wood Sandpiper is rare. June sees the fewest records and lowest numbers, with generally no more than four recorded.
Vaughan and Jones (1913) referred to Wood Sandpiper as a common passage migrant ‘often occurring in large flocks, which frequent both the coast and the country inland’, noting it from 21 August to 5 May. Macfarlane and Macdonald (1966) said it was known to be a regular passage migrant with up to 250 birds in spring and 50 in autumn, mainly from the paddy areas of the northwest New Territories; extreme dates were 1 February to 22 May and 27 July to 27 December.
Herklots (1967) commented that it was mainly recorded in paddy areas, which are rare now in HK, and there appears to have been a decline associated with this. Relatively high counts during the late 1960s and early 1970s at a time when there were much lower levels of observer activity compared to the 1990s supports such an interpretation. Numbers reported in autumn since 2010 appear consistently lower than those in the 20 years prior.
BEHAVIOUR, FORAGING & DIET
A characteristic bird of freshwater and brackish wetland areas, with small groups of birds readily flying up and calling when flushed. Forages in shallow water or wet mud, pecking at the water or mud surface and sweeping bill through the water.
RANGE & SYSTEMATICS
Monotypic. Breeds from northern and central Europe east through Russia, northern Kazakhstan, northern Mongolia and northeast China to Kamchatka; winters in sub-Saharan Africa, parts of the Middle East, the Indian subcontinent, south China, Indochina, southeast Asia and Indonesia to Australia (Van Gils et al. 2020). In China breeds in the northwest and northeast and winters along the south coast, including Hainan and Taiwan (Liu and Chen 2020).
CONSERVATION STATUS
IUCN: Least Concern. Population trend stable.
Figure 1.
Herklots, G. A. C. (1967). Hong Kong Birds (2nd ed.). South China Morning Post, Hong Kong.
Liu, Y. and Y. H. Chen (eds) (2020). The CNG Field Guide to the Birds of China (in Chinese). Hunan Science and Technology Publication House, Changsha.
Macfarlane, A. M. and A. D. Macdonald, revised by Caunter, J. R. L. and A. M. Macfarlane (1966). An Annotated Check-list of the Birds of Hong Kong. Hong Kong Bird Watching Society, Hong Kong.
Van Gils, J., P. Wiersma, and G. M. Kirwan (2020). Wood Sandpiper (Tringa glareola), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.woosan.01
Vaughan, R. E. and K. H. Jones (1913). The birds of Hong Kong, Macao and the West River or Si Kiang in South-East China, with special reference to their nidification and seasonal movements. Ibis 1913: 17-76, 163-201, 351-384.
