White Wagtail (Motacilla alba) - HBW 9, p. 777

Taxonomy: Motacilla alba Linnaeus, 1758, Sweden.
Thought to form a superspecies with M. maderaspatensis, M. grandis and M. aguimp, all of which formerly often regarded as races of present species, and with recently described M. samveasnae; some recent analyses of mitochondrial DNA, however, suggest that M. aguimp possibly more distantly related to that group. Geographical variation marked and complex. Races often divided into four groups on basis mainly of breeding range: “nominate group” (including also yarrellii, persica, dukhunensis, personata, baicalensis), “alboides group” (with leucopsis), “lugens group” (with ocularis), and single-taxon “subpersonata group”. In addition, several races sometimes regarded as separate species, but widespread intergradation occurs where races meet, and frequent co-occurrence evident in non-breeding quarters; in particular, lugens and personata often ranked as full species, but former appears to intergrade and interbreed with both leucopsis and ocularis, and latter with dukhunensis, alboides and baicalensis. Moreover, the described taxa persica and dukhunensis may be only inter-racial hybrids, perhaps better included within nominate. Proposed race frontata (described from Xiamen, SE China, where probably only migrant) provisionally included in leucopsis, though possibly of hybrid origin. Other named races include forwoodi (described from Abd al Kuri I, W of Socotra), included in nominate; and albula (Khasi Hills, in NE India), considered inseparable from alboides. Eleven subspecies currently recognized.