See also:
Phylloscopus collybita Vieillot, 1817
Phylloscopus collybita abietinus Nilsson, 1819
Phylloscopus collybita tristis Blyth, 1843

Synonyms

Phylloscopus collybita axillaris Sushkin, 1904
Phylloscopus collybita altaiana Sushkin, 1925
Phylloscopus collybita riphaea Snigirevski, 1931

Description. The upperparts are brown with the slightly greenish-olive tinge; the underparts are without yellow color, or sometimes with slightly expressed yellow spots. The greenish tinge on the rump is less intensive than on abietinus.

Distribution. Breeds in Kokchetav upland, Shortandy area and in Pavlodar Trans-Irtysh area, in south probably up to Karkaralinsk. On migration occurs throughout.

References

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