The White wagtail (Motacilla alba) is a small insectivorous bird of the open country, often near habitation and water. It prefers bare areas for feeding, where it can see and pursue its prey. In urban areas, it has adapted to foraging on paved areas such as car parks. It is the national bird of Latvia and has been featured on the stamps of several countries.
The White wagtail is a slender bird with the characteristic long, constantly wagging tail of its genus. There are a number of other subspecies, some of which may have arisen because of partial geographical isolation, such as the resident British and Irish form, the pied wagtail M. a. yarrellii, which now also breeds in adjacent areas of the neighbouring European mainland. The Pied wagtail exchanges the grey colour of the nominate form with black (or very dark grey in females), but is otherwise identical in its behaviour. Other subspecies, the validity of some of which is questionable, differ in the colour of the wings, back, and head, or other features. Some races show sexual dimorphism during the breeding season. As many as six subspecies may be present in the wintering ground in India or Southeast Asia and here they can be difficult to distinguish.
White wagtails breed throughout Eurasia, only being absent in the Arctic. They also breed in the mountains of Morocco and western Alaska. These birds are residents in the milder parts of their range such as western Europe and the Mediterranean, but migratory in much of the rest of their range. Northern European breeders winter around the Mediterranean and in tropical and subtropical Africa, and Asiatic birds move to the Middle East, India, and Southeast Asia. Birds from the North American population also winter in tropical Asia. White wagtails occupy a wide range of habitats but are absent from deserts. They inhabit grasslands, seashores, rocky shorelines, sand beaches, tidepools, rivers, lakeshores, farmland, gardens, and parks. They are also often found in towns and villages.
White wagtails are usually seen alone or in pairs, but during migration, they often gather in flocks at good feeding areas or roost at night. These birds feed by day on the ground or on the wing. They may also forage in shallow water catching prey in the mud or may hover over water. The most conspicuous habit of White wagtails is a near-constant tail wagging, a trait that has given the birds their common name. The reasons for this behavior are poorly understood but it has been suggested that wagtails may flush prey, or signal submissiveness to other wagtails. The call of these birds is a sharp 'chisick' and their song consists of twittering phrases; the males use a series of contact calls to attract the female.
White wagtails are carnivores (insectivores). Terrestrial and aquatic insects and other small invertebrates form a major part of their diet. These include beetles, dragonflies, small snails, spiders, worms, crustaceans, maggots found in carcasses, and, most importantly, flies.
White wagtails are monogamous; they form pairs and defend their breeding territories. The breeding season for most is from April to August, with the season starting later further north. Both sexes build the nest; the male initiates the nest building and the female finishes the process. The nest is a rough cup assembled from twigs, grass, leaves, and other plant matter. It is lined with soft materials, including animal hair. The nest is set into a crevice or hole - traditionally in a bank next to a river or ditch - but White wagtails have also adapted to nesting in walls, bridges, and buildings. The female lays 3 to 8 cream-colored eggs, often with a faint bluish-green or turquoise tint, and heavily spotted with reddish-brown. Both parents incubate the eggs, although the female generally does so for longer and incubates at night. The eggs begin to hatch after 12-16 days. Both parents feed the chicks until they fledge after between 12 and 15 days, and then continue to feed them for another week after fledging.
White wagtails are widespread throughout their range and are not endangered at present. However, they are caught for sport and often then placed into collections. They are also kept as pets and eaten as food. Climate change may also affect the time of their migration.
According to the IUCN Red List, the total White wagtail population size is 135,000,000-221,000,000 mature individuals. In Europe, the breeding population consists of 16.9-27.6 million pairs, which equates to 33.9-55.2 million mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
