Green Sandpiper Tringa ochropus 白腰草鷸
Category I. Uncommon passage migrant and winter visitor, rare in summer; occurs in a wide variety of freshwater wetlands.
IDENTIFICATION
Dec. 2008, FUNG Hon Shing.
21-24 cm. Slightly larger and longer-winged than Wood Sandpiper. Upperparts are rather dark with relatively discreet whitish marks (compared to Wood Sandpiper), the chest is slightly darker and has a clear-cut border with white belly. There is a fairly broad supercilium that does not extend behind the eye, the bill is medium-length and has a paler basal half and the legs are greenish.
Ageing birds is tricky. Juveniles have duller wing coverts and tertials with small contrasting buff spots along the edge that form a narrow buff subterminal bar across the width of the feather. The white bars on the central tail feathers are narrower, more irregular and buffish compared to adults (Meissner and Cofta 2021).
Jan. 2023. Sarawak, Malaysia. Dave Bakewell.
When flushed it flies off showing dark upper and underwings, white rump with broad bars on tail (which often looks all-dark) and white underparts, distinguishing it from Wood Sandpiper (in addition to call).
VOCALISATIONS
When flushed gives a loud, high-pitched, ringing, multi-syllabic call.
The alarm call is a repeated ‘plip plip plip…’ with a similar ringing quality but not quite so high-pitched.
DISTRIBUTION & HABITAT PREFERENCE
Most records are from the brackish fish pond areas around Deep Bay. However, this species is regular in freshwater wetlands elsewhere, including channelised and natural watercourses both small and large, wet and mixed wet and dry agriculture and freshwater marsh. It occurs at low densities everywhere, and always in lowland areas. It is rare in intertidal areas, and then only in freshwater channels running through the mangrove or onto the mudflat.
Away from the mainland New Territories there are very few records. There are eight records from Po Toi spread more or less evenly across the winter period from August to April, one record from Peng Chau and one of migrants over the sea south of Hong Kong on 7 April 2018.
OCCURRENCE
Green Sandpiper is an uncommon passage migrant and winter visitor, that is rare in summer. Figure 1 illustrates the pattern of occurrence during the year in the Deep Bay area based on the monthly waterbird counts since 1979. Numbers are lowest in June and gradually rise to peak in January; numbers in March are higher still, indicating migrants pass through at this time, and then decline in April through May. The pattern of occurrence elsewhere is similar though lacks the pronounced March peak.
The highest count is 130 on 19 March 2017. The highest single-site count away from the Deep Bay area is 28 at Kam Tin. Figure 2 illustrates the peak winter period Deep Bay count since 1979. Based on winter waterbird counts in Deep Bay Sung et al. (2021) concluded that the wintering population declined from 1998 to 2017.
BEHAVIOUR, FORAGING & DIET
Single birds are often encountered at the water’s edge or walking through shallow water. When flushed birds calls loudly during an often zig-zagging flight before alighting some distance away.
RANGE & SYSTEMATICS
Monotypic. Breeds across the Palearctic from Scandinavia east to northeast Siberia and south to northern parts of Kazakhstan and Mongolia largely between 45oN and the Arctic Circle; winters in western and southeast Europe, north and sub-Saharan Africa, the Middle East, the Indian subcontinent east to south China and south to southeast Asia and Borneo (Van Gils et al. 2020). In China breeds in the northwest and northeast, and winters southeast of a line from Beijing to western Yunnan (Liu and Chen 2020).
CONSERVATION STATUS
IUCN: Least Concern. Population trend increasing.
Figure 1.
Figure 2.
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.
Meissner, W. and T. Cofta (2021). Ageing and sexing the Green Sandpiper Tringa ochropus. Wader Study 128(2): 153-156 doi:10.18194/ws.00232
Sung, Y. H., C. C. Pang, T. C. H. Li, P. P. Y. Wong and Y. T. Yu (2021). Ecological Correlates of 20-Year Population Trends of Wintering Waterbirds in Deep Bay, South China. Frontiers in Ecology and Evolution. Published 20 April 2021 doi: 10.3389/fevo.2021.658084
Van Gils, J., P. Wiersma, and G. M. Kirwan (2020). Green Sandpiper (Tringa ochropus), 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.grnsan.01
