See also:
Motacilla flava Linnaeus, 1758
Motacilla flava beema Sykes, 1832
Motacilla flava flava Linnaeus, 1758
Motacilla flava zaissanensis Polyakov, 1911
Motacilla flava leucocephala Przevalski, 1887

Synonyms

Motacilla flava borealis Sundevall, 1842
Motacilla flava plexus Thayer et Bangs, 1914
Motacilla flava angarensis Sushkin, 1925

Description. The head is dark-grey, darker than on flava; the ear coverts are usually blackish not grey; white supercilium no or faint; the chin is yellow sometimes white.

Distribution. On migration occurs throughout in Kazakhstan. On Chokpak Pass migrates 1 April – 25 May and 2 September – 26 September; on Sorbulak lake 31 March – 25 May and 2 September – 23 September.

References

Gavrilov E. I., Gavrilov A. E. "The Birds of Kazakhstan". Almaty, 2005
Э.И.Гаврилов. "Фауна и распространение птиц Казахстана". Алматы, 1999.