Elegant wagtail, some 20 cm in length with a long narrow tail, bobing up and down all the time (you can probably see in pics, as I was shooting from a decent distance, there is always a movement-due blur on tail). Grey above, and white and yellow below, with dark grey head decorated by two white stripes, almost joining at the level of beak.
Seen in mountainous region north of Tbilisi, and very close to Russian border. Coniferous forests, barren rocks and cold-climate grasslands in valleys on some 2000 m of altitude, on edges of urban habitations. Observed in a small rapid stream.