Eastern Yellow Wagtail Motacilla tschutschensis macronyx 東黃鶺鴒
Category I. M. t. macronyx is a scarce passage migrant and winter visitor mainly to wetland habitats in the Deep Bay area but also to migrant sites elsewhere.
IDENTIFICATION
Dec. 2020, Roman Lo. Adult.
17 cm. Adult male in breeding plumage has dark bluish-grey crown and nape, and darker blackish lores, forehead and ear coverts. Usually there is no supercilium, though it may be faint behind the eye. Rarely shows necklace of dark spots. Adult female in breeding plumage is duller than male and has mid-grey head with only slightly darker lores; the supercilium (present more often than on male) is narrow and indistinct and lies over lores and only just behind eye.
Feb. 2010, Michelle and Peter Wong. First-winter.
Non-breeding plumage of adults is duller than breeding plumage. First-years either lack or have a faint and narrow supercilium and may be rather peachy on the chest (Alström et al. 2013).
VOCALISATIONS
The typical flight call of the three commonly-occurring Eastern Yellow Wagtail taxa in HK is a rather harsh ‘tzeep’ that falls in pitch terminally and is similar to that of Citrine Wagtail.
DISTRIBUTION & HABITAT PREFERENCE
All taxa of Yellow Wagtails frequent low-lying marshy areas, wet agricultural areas, fish ponds, reclaimed areas and other open country habitats, mainly in the northwest New Territories. It occurs too infrequently for the winter atlas surveys to reveal any changes in distribution.
OCCURRENCE
M. f. macronyx, the least numerous of the Eastern Yellow Wagtail taxa in HK, is a passage migrant in spring and autumn and a scarce winter visitor (Figure 1). The autumn peak occurs in the middle two weeks of October, which is followed by a decline to the end of November. The spring peak appears to be in the last week of April and first week of May, though this may be an artefact of one high count in each of these weeks in 1999 (see below) against a backdrop of single-figure counts generally.
Extreme dates of occurrence are 30 August 2015 and 20 May 1982. The highest counts are 100 at Cape D’Aguilar on 1 May 1999 and 75 at Chek Lap Kok on 27 April 1999, both influenced by the close approach of a tropical storm. Otherwise, the highest spring count is 35 on 28 March 2004, while the highest autumn count is 50 at Tsim Bei Tsui on 4 October 1994 and at Long Valley on 7 October 1995; in addition, the majority of 80 Eastern Yellow Wagtails at Nam Sang Wai on 20 October 1995 were also this taxon. The highest count in winter is of 17 at Lok Ma Chau on 26 January 1993.
Herklots (1934, 1953) considered macronyx to be a very rare migrant, while Dove and Goodhart (1955) regarded it as the rarest of the taxa. Macfarlane and Macdonald (1966) stated macronyx was uncommon in spring but occasionally abundant in autumn.
BEHAVIOUR, FORAGING & DIET
Walks and runs pumping tail, but less intensely than White Wagtail. Flight is slightly weaker than that of White Wagtail, and more resembles pipits. Generally showy and vocal, if not very approachable. More likely to occur in flocks than White Wagtail, on migration and when foraging. Forages on invertebrates on the surface of mud and plants, but no details.
RANGE & SYSTEMATICS
M. t. macronyx breeds in south central Siberia, northeast Mongolia and northeast China (hence the name ‘Manchurian Yellow Wagtail’); it winters from southeast China, including Hainan and Taiwan, through southeast Asia as far as the Malay Peninsula (Badyaev et al. 2020, Liu and Chen 2020).
Eastern Yellow Wagtail M. tschutschensis comprises four subspecies: plexa, tschutschensis, macronyx and taivana.
CONSERVATION STATUS
IUCN (Motacilla tschutschensis): Least Concern. Population trend decreasing.
Figure 1.
Alström, P., K. Mild and B. Zetterström (2003). Pipits and Wagtails of Europe, Asia and North America. Christopher Helm, London.
Badyaev, A. V., B. Kessel, D. D. Gibson, J. del Hoyo, and N. Collar (2020). Eastern Yellow Wagtail (Motacilla tschutschensis), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.eaywag.01
Dove, R. S. and H. J. Goodhart (1955). Field observations from the Colony of Hong Kong. Ibis 97: 311-340.
Herklots, G. A. C. (1934). The birds of Hong Kong. Part XVI. Family Motacillidae (Pipits and wagtails). Hong Kong Naturalist 5: 163-169.
Herklots, G. A. C. (1953). Hong Kong Birds. 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.
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.
