Citrine wagtail (Motacilla citreola)

The citrine wagtail is a small songbird in the family Motacillidae. Its systematics, phylogeny and taxonomy are subject of considerable debate in the early 21st century. This is because this bird forms a cryptic species complex with the eastern and western yellow wagtail. Which of the many taxa in this group should properly refer to which population is unlikely to be resolved in the immediate future.