Also known as the Pied Wagtail, the White Wagtail is a slender bird, 16.5-19 cm (6?-7? in) in length (East Asian subspecies are longer, measuring up to 21 cm (8 in), with the characteristic long, constantly wagging tail of its genus. Its average weight is 25 g (0.88 oz) and the maximum lifespan in the wild is ca. 12 years. The nominate subspecies Motacilla alba alba is basically grey above and white below, with a white face, black cap and black throat. The most conspicuous habit of this species is a near-constant tail wagging, a trait that has given the species, and indeed the genus, its common name.
Habitat and Distribution
This species breeds throughout Eurasia up to latitudes 75N, only being absent in the Arctic from areas where the July isotherm is less than 4?C. It also breeds in the mountains of Morocco and western Alaska. It occupies a wide range of habitats, but is absent from deserts. White Wagtail is resident in the milder parts of its range such as western Europe and the Mediterranean, but migratory in much of the rest of its 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.
The exact composition of the diet of White Wagtails varies by location, but terrestrial and aquatic insects and other small invertebrates form the major part of the diet. These range from beetles, dragonflies, small snails, spiders, worms, crustaceans, to maggots found in carcasses and, most importantly, flies in the order Diptera. Small fish fry have also been recorded in the diet. The White Wagtail is somewhat unusual in the parts of it range where it is non-migratory as it is an insectivorous bird that continues to feed on insects during the winter (most other insectivorous birds in temperate climates migrate or switch to more vegetable matter)..
White Wagtails are monogamous and defend breeding territories. The breeding season for most is from April to August, with the season starting later further north. Both sexes are responsible for building the nest, with the male responsible for initiating the nest building and the female for finishing the process. For second broods in the subspecies personata the female alone builds the nest as the male is still provisioning the young. which 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 the species has also adapted to nesting in walls, bridges and buildings. One nest was found in the skull of a walrus. They species will nest in association with other animals, particularly where available the dams of beavers and also inside the nests of Golden Eagles. Around 3-8 eggs are laid, with the usual number being 4-6. Its eggs are cream-coloured, often with a faint bluish-green or turquoise tint, and heavily spotted with reddish brown; they measure, on average, 21?15 mm (0.83?0.59 inches). Both parents incubate the eggs, although the female generally does so for longer and incubates at night. The eggs begin to hatch after 12 days (sometimes as late as 16 days). Both parents feed the chicks until they fledge at around 14 days, and the chicks are fed for another week after fledging.
Calls and Songs
The call of the White Wagtail is a sharp chisick, slightly softer than the version given by the Pied Wagtail. The song is a pleasant twittering, more regular in White than Pied, but with little territorial significance, since the male uses a series of contact calls to attract the female.