all photos of serie (clickable):
comments:2021-04-19. Jochen Roeder:
The grey back, yellow supercilium reaching all the way around the ear coverts and white undertail coverts suggest this is a citrine wagtail Motacilla citreola.
2021-04-19. Robert Parker:
Ok, thanks. I've been confused about these two.
2021-04-19. Jochen Roeder:
You are more than welcome. Citrine Wagtail is one of my favourite bird species. Very nice picture. Happy birding trails in Kazakhstan!