[2] Motacilla is the Latin name for the pied wagtail; although actually a diminutive of motare, "to move about", from medieval times it led to the misunderstanding of cilla as "tail".
[3] At first glance, the wagtails appear to be divided into a yellow-bellied group and a white-bellied one, or one where the upper head is black and another where it is usually grey, but may be olive, yellow, or other colours.
mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequence data (Voelker, 2002) is of limited use: the suspicion that there is a superspecies of probably three white-bellied, black-throated wagtails is confirmed.
Wagtails spread rapidly across Eurasia and dispersed to Africa in the Zanclean (Early Pliocene)[4] where the sub-Saharan lineage was later isolated.
The two remaining "monochrome" species, Mekong and African pied wagtail may be closely related, or a most striking example of convergent evolution.
They are ground nesters, often in rock crevices on steep banks or walls, laying (3–)4–6(–8) speckled eggs at a time.