Spotted Redshank Tringa erythropus 鶴鷸
Category I. Scarce passage migrant, slightly more numerous in spring, and rare summer visitor; much declined. Occurs in vegetated freshwater wetlands.
IDENTIFICATION
May 2014, Michelle and Peter Wong. Adult, breeding plumage.
29-32 cm. Adult in breeding plumage is unmistakeable as it is dark sooty spotted white above with dark legs.
Dec. 2011, Michelle and Peter Wong. Adult, non-breeding plumage.
In winter appears distinctly greyish above with white underparts, whitish forepart of head and red legs. Juveniles have pale spotted fringes to brown upperpart feathers with darker bars and paler reddish legs and underparts extensively marked brown.
Differs from Common Redshank in lacking broad white area at rear of wing in flight, more elegant proportions, longer legs and bill (the latter finer with the reddish base largely confined to lower mandible) and more obvious supercilium above lores when not in breeding plumage. When feeding usually wades in deeper water.
VOCALISATIONS
The characteristic and distinctive flight call is an inflected disyllabic ‘chew-it’ or very occasionally, as in the second call in this recording, the reverse, ‘it-chew.’
DISTRIBUTION & HABITAT PREFERENCE
Most records are from the intertidal mudflats of Deep Bay and adjacent roosting areas, primarily Mai Po NR, but also fish pond areas and the Kam Tin Main Drainage Channel. At Long Valley up to ten birds have been recorded, most since autumn 2011.
There are less than 15 records away from these sites. Last century these consisted primarily of up to four birds at Kai Tak, Luk Keng, Long Valley, Starling Inlet and Shuen Wan, with the highest count being 14 at Starling Inlet on 28 March 1965. This century the only records away from the northern New Territories have occurred Lantau on 8 October 2020 and 11 November 2016.
OCCURRENCE
The first autumn migrants are generally noted during the second week of August (Figure 1). Passage during September to mid-October is desultory at best, with the highest count since 2006 being 72, compared with 191 previously.
The winter flock appears to arrive rather late in the year, as is illustrated in Figure 2, which shows the mean monthly count during waterbird counts since 1998. The highest count during winter (defined as the period from mid-December to mid-February) is 2,500 on 20 January 2002. However, as Figure 3 indicates, there has been a substantial decline in the size of the wintering flock such that since winter 2009/10 the highest count is a mere 186, lower than almost every previous year since winter waterbird counts were first carried out in January 1979.
It may be that the wintering flock remains substantially intact until late March, when numbers are augmented by northward-bound migrants (Figure 2). Peak spring passage occurs in April when the highest counts are 2500 on 17 April 1987 and 2000 on 3 April 1997. However, as Figure 4 shows, there was a sharp decrease in the peak spring count from 2006 to 2012, and all peak spring counts during 2019-2021 were fewer than 50.
There are relatively few records during the summer, and most counts from the last week of May to the first week of August are of one or two birds.
Vaughan and Jones (1913) referred to the Spotted Redshank as a ‘fairly common winter visitor’, often in flocks of several hundred birds, though strictly confined to the intertidal mudflats. However, it is possible that they never actually saw it in HK, and Walker (1958) appears to be the first to have recorded it here with certainty when he noted it from 4 April to 20 May 1956. Macfarlane and Macdonald (1966) referred to up to 135 birds in January and February, with many fewer on migration.
BEHAVIOUR, FORAGING & DIET
Often forages in deep water when it has an appearance similar to a crane Grus sp. (hence its Chinese name). Sometimes swims while feeding and may immerse both head and neck. Gregarious, gathering in large flocks when sufficient numbers present.
RANGE & SYSTEMATICS
Monotypic. Breeds north of the Arctic Circle from Scandinavia east to Chukotka, and winters in north and sub-Saharan Africa south to Tanzania, the Middle East, western and southern parts of the Indian subcontinent, and mainland coastal areas of the South China Sea (Van Gils et al. 2020). In China breeds in central Xinjiang and winters in southeast coastal provinces, including Hainan and Taiwan (Liu and Chen 2020).
CONSERVATION STATUS
IUCN: Least Concern. Population trend stable.
Figure 1.
Figure 2.
Figure 3.
Figure 4.
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). Spotted Redshank (Tringa erythropus), 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.spored.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.
Walker, F. J. (1958). Field observations on birds in the Colony of Hong Kong. Hong Kong Bird Watching Society, Hong Kong (duplicated).
