(motacilla citreola)
The Citrine Wagtail is a somewhat rare vagrant in Scotland. It breeds mainly in eastern Europe and eastwards into Asia. However, its range has been expanding westwards and it now breeds in Poland and the Baltic states. The number of Scottish sightings has increased in recent years probably due to this range expansion and also because of improved identification of juvenile birds.
The bird in these photographs was one of two which were found on Shetland in the autumn of 2018, both being 1st winter/juvenile birds.