Wagtail, a group of about 30 species of birds native to the Old World. One species, the white wagtail, has become naturalized in Alaska. Wagtails are seven to nine inches (18 to 23 cm) long, including their relatively long tails. They are found in open meadows and on the banks of ponds and streams, feeding on insects, snails, and worms. The birds are most often seen running swiftly along the ground, constantly flicking their tails up and down. The nests are made on the open ground and in holes in banks, rocks, and trees. The female lays four to six bluish eggs with yellow markings.
Wagtails form the genus Motacilla of the family Motacillidae. The white wagtail is M. alba.