The wagtails are a genus, "Motacilla", of passerine birds in the family "Motacillidae". The forest wagtail belongs to the monotypic genus "Dendronanthus" which is closely related to "Motacilla" and sometimes included herein. The common name and genus names are derived from their characteristic tail pumping behaviour. Together with the pipits and longclaws they form the family "Motacillidae".

Wagtails are slender, often colourful, ground-feeding insectivores of open country in the Old World. Species of wagtail breed in Africa, Europe and Asia, some of which are fully or partially migratory. Two species also breed in Alaska, and wintering birds may reach Australia.

They are ground nesters, laying up to six speckled eggs at a time. Among their most conspicuous behaviours is a near constant tail wagging, a trait that has given the birds their common name. In spite of the ubiquity of the behaviour and observations of it, the reasons for it are poorly understood. It has been suggested that it may flush up prey, or that it may signal submissiveness to other wagtails. Recent studies have suggested instead that it is a signal of vigilance that may aid to deter potential predators.

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