White Wagtail Motacilla alba lugens 白鶺鴒
Category I. Rare winter visitor to open country habitats.
IDENTIFICATION
16.5-18 cm. Adult male in breeding plumage has black upperparts, white median and greater coverts forming a wing panel, black eye stripe that broadens notably at the rear, white upper throat and largely white flight feathers and primary coverts that are visible only in flight. Adult female in breeding plumage has greyish-black mantle and scapulars, and less white in the wings.
Mar. 2023, Roman Lo.
Adult winter birds have white throat and grey upperparts with varying amount of blackish feathers, more on male. First-winter birds have grey on the mantle and scapulars, sometimes with small blackish spots, and all-white median and greater coverts (the latter allowing separation from ocularis). See Alström et al. (2003) for further detail.
VOCALISATIONS
The typical flight call is probably indistinguishable from ocularis: a double note ‘chee-chik’; also ‘chik’ or ‘chee-chik-chik’, similar in tone to Grey Wagtail.
DISTRIBUTION & HABITAT PREFERENCE
Wetland-associated, and thus frequently seen near water but not dependent on it, most open-country rural habitats are utilised apart from grassland and grassland-shrubland.
OCCURRENCE
Figure 1 illustrates the pattern of occurrence from 1999 to 2020 and indicates that lugens is a rare winter visitor; extreme dates are 5 October 2008 and 12 April 2009. Highest numbers occur in the second half of December and January. The maximum count is of four at Pak Nai on 30 January 2017.
BEHAVIOUR, FORAGING & DIET
Forages by walking or running after insects, and occasionally by leaping up to catch them mid-air or after a short aerial pursuit. Tail-pumping is frequently carried out while walking and perched, and at a greater speed upon landing or after running.
There is one report of a bird joining a nocturnal roost of leucopsis and ocularis, which was at HK International Airport.
RANGE & SYSTEMATICS
Breeds in east Siberia on the Kamchatka Peninsula, Sakhalin and in Ussuriland and northern Japan; winters in Japan and east Asia (Badyaev 2020). In China a migrant and winter visitor to the east (Liu and Chen 2020), while HK records indicate it winters in small numbers along this part of the south coast.
Polytypic species of many subspecies. Those recorded in Hong Kong are leucopsis, ocularis, lugens and personata.
CONSERVATION STATUS
IUCN (Motacilla alba): Least Concern. Population trend stable.
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., D. D. Gibson, B. Kessel, P. Pyle, and M. A. Patten (2020). White Wagtail (Motacilla alba), 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.whiwag.01
Liu, Y. and Y. H. Chen (2020). The CNG Field Guide to the Birds of China (in Chinese). Hunan Science and Technology Publication House, Changsha.
