The description given does sound very much like our local wagtail: a first
winter bird which has the yellow wash on the face. First summer males
should have a black back, and a pure white forehead, while females have
grey mixed in (if I am reading correctly from Shigeta, 1996) so it is
probably moulting into first summer plumage from first winter plumage. I
have not yet tracked down photos of sexed first winters and I only have
reference to one ocularis photo so far which is a female: this has a grey
back fading in to a slightly darker grey rump; the wing panel of secondary?
coverts has grey centres to the feathers and is not bright white like
typical lugens; it also has a black throat and a black line which almost
joins the nape to the breast patch. So I think it is unlikely that your
bird is an ocularis. baicalensis and ocularis both have white faces.
I understand that lugens was split on the basis of Russian papers
(Kistchinski and Lobov 1979, Nazarenko 1968) indicating breeding sympatry
and different mating displays with lugens and ocularis. These papers formed
the basis of a paper by Joe Morlan which was published in Continental
Birdlife in 1981. Since then the distributions of these 2 forms have
changed, with lugens spreading out around Japan and coming into more
breeding contact with ocularis in Kyushu, near Osaka and on Sado island in
the Japan Sea. It is clearly interbreeding with it frequently. Whether
there is any ecological separation or assortative mating I don't know . Nor
do I know the degree of introgression. The flight calls are reported to be
different (Nial Moores) but it does not seem that they are of sufficient
difference to prevent mating. M. (a.)lugens is not accepted as a distinct
species here in Japan, but why tick only species anyway?
Des Allen
Tokyo
At 10:03 PM 98.4.7 +1000, palliser wrote:
>Niven and others
>
>As requested here is part of the description taken directly from my note
>book (please excuse format) relating to the Glendale Wagtail. The identity
>and age of this bird is still being worked on but it looks like a female
>lugens (Black-backed Wagtail) perhaps at the end of its first year.(A first
>summer bird?) but further research is needed to be certain. Motacilla alba
>ocularis is still the main problem.
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