Contributed by Alfred Chia 2nd January 2016.
On 27 December 2015, Vincent Lao saw and photographed three White Wagtails (Motacilla alba) feeding in a canal alongside the SMRT Depot in Bishan. This species is an uncommon winter visitor to Singapore & is seen every year but in small numbers. It is almost always seen feeding in canals & near waterways. The canal in Bishan is a known haunt of this wagtail.
I first saw Vincent’s pictures on Facebook with the three wagtails in one frame. After zooming in, I noted that two of these were of the commoner ‘leucopsis’ race. The third bird, with a black eye-stripe, was different. This was initially identified as the ‘ocularis’ race: the uncommoner race of White Wagtail that was known to occur in Singapore.
Bird on right initially IDed as ‘ocularis‘ while other two on left are ‘leucopsis‘.
After Vincent uploaded more close-up images of the supposedly ‘ocularis’ bird, I noted that there were some differences which may question the initial identification of the ‘ocularis‘- primary of which was the large white wing panel, a feature not consistent with a first-winter ‘ocularis‘ but that of the ‘lugens’ race. Further research & checks with the literature I had further aroused my suspicion.
Extreme wear on the tertials suggest a first-winter bird. Note also the large white wing panel & paler bill base.
I then sought advice & expert help from others more familiar with White Wagtails on the advice of Dave Bakewell. Immaculate images taken by Vincent of the third bird was first sent to Dr Nial Moores, Director of Birds Korea. He replied promptly indicating confidently that all features point to a ‘lugens’. As this race very rarely occur so far south but in more northerly places (even during migration), Dr Nial suggests to seek another opinion, perhaps from a wagtail expert. Dr Nial’s analysis is appended below:
“My opinion of lugens is based on a combination of features. The importance of many of the features depends to a large extent on the age of the bird of course.
I would age this bird as a First-winter based on the extreme wear in the tertials; the brownish tone to some of the flight feathers; the lack of solid white edge to the primaries on the closed wing; the brownish tone to parts of the upperpart grey (e.g. on the scapulars); the obviously paler bill base; and the dark alula. If it is a First-winter, then the extent of white on the wing coverts and secondaries of the closed wing should be well beyond what would be expected in an ocularis of the same age. It is good for lugens, which at this age also often shows a few darker centres “shining through” the white of the coverts as this bird does.
If that ageing is for some reason shown to be incorrect, then I would still point to the scattered blackish feathers on the scapulars; the apparently darker lower rump (blackish?) than back; the strength of the eye-stripe; the diffusely grey wash on much of the underparts; the extent of white suggested on the secondaries; and the more extensive bib for a bird still in non-breeding plumage. All suggest lugens to me. Without images that show it in direct comparion with other white wagtails it is difficult to be confident about the shade and tone of upperpart grey of this bird. However, based on the degree of contrast with the more obviously blackish parts of the bird, I would also think this within the expected range of female lugens: a kind of dull grey without any of the blue-grey or light ash of the vast majority of ocularis”.
The dark black rump is indicative of a young lugens White Wagtail. Young of ocularis race has greyer rump.
Further advise was sought from Dr Per Alstrom, a lecturer of systematics and evolutionary research and author of Pipits & Wagtails of Europe, Asia and North America. He too confirmed that the bird is “indeed a lugens“, pointing to the “blackish spots on the scapulars & mantle”.
“Blackish spots (blotches) on the scapulars & mantle” or “scattered blackish feathers on the scapulars”.
The ‘lugens‘ race breeds on southern and eastern Kamchatka, the Kuriles, Sakhalin, coasts of the Sea of Okhotsk, lower Amur Valley and coastal Ussuriland to southern Ussuriland. It also breeds in most of Japan and occasionally breeds in coastal Alaska.
It winters in Japan from Honshu southward, and south through the Nansei Shoto Islands to Taiwan and southern China from the lower Yangtze Valley southward. It is however a vagrant to the Philippines, Australia and western North America. There is apparently also a single isolated record of a black-backed spring adult photographed in Singapore in late March of 1993 (Wells, 2007). Other than this lone Singapore record, there may not be any record of ‘lugens‘ in the Peninsula or nearby region.
With input from two who are experienced & familiar with wagtails, this record is currently being reviewed by the Records Committee of the Bird Group. If accepted, this will be the second record of a ‘lugens‘ race White Wagtail in Singapore, after a lapse of 22 years! It is to be noted however that possibilities of past sightings of “ocularis” Whites being overlooked due to the close resemblance of the two races exists.
The Bird Group would like to express their appreciation & thanks to Vincent Lao for so kindly and promptly sharing his images & record of this sighting.
Many thanks to Vincent Lao for use of his excellent photos in this article.
Thanks & appreciation also to Dr Nial Moores & Dr Per Alstrom for their comments and input on the wagtail and to Dave Bakewell for his kind advice.
Alstrom, P., & Mild, K. (2003). Pipits and Wagtails. Christopher Helm, London.
Lim, K.S. (2009). The Avifauna of Singapore. Nature Society (Singapore), Singapore.
Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula, Vol 2: Passerines. AC & Black, UK.