Pied wagtails, a subspecies of the white wagtail (Motacilla alba), are common backyard birds in Britain where they live year round feeding on insects and occasionally seeds.
They are very versatile birds in the human environment, nesting in cavities in trees, cliffs, abandoned buildings and even old machinery. Sometimes their choice is unusual, as when a pair nested in the barrel of an old 1894 battlecruiser gun.
Wagtails are well named for their most noticeable behavior. More than a habit, they just can’t help bobbing their tails. They are already wagging from a very young age.
Watch them at their nest in this BBC video from 2019.
Throwback to #Springwatch 2019 when our pied wagtail chicks flew out into the world for the first time! ??
— BBC Springwatch (@BBCSpringwatch) May 1, 2020
Who’s excited for #Springwatch this year? ???????? pic.twitter.com/HIgGccuTWs
(photo from Wikimedia Commons, embedded tweet from BBC Springwatch)