Common Bulbul (Pycnonotus barbatus) - HBW 10, p. 181

Taxonomy: Turdus barbatus Desfontaines, 1789, “Côtes de Barbarie” = near Algiers, Algeria.
Genus as currently constituted probably polyphyletic; in-depth analysis of morphology, voice, behaviour and genetics required to redefine its limits. Present species forms a superspecies with P. nigricans, P. capensis, P. xanthopygos, P. leucotis and P. leucogenys, possibly including some other species. Hybridizes extensively with first two of these in narrow transition zones along at least part of boundaries between their respective distributions; old record of a mixed pair of present species and P. xanthopygos, but no hybrids known (and ranges apparently do not meet). Races tricolor, dodsoni and somaliensis sometimes treated as separate species on basis of plumage differences (colour of head and undertail-coverts, presence or absence of white patch on neck side, and plain or mottled breast pattern), but intermediates known in many cases. The whole complex merits further study. Races gabonensis and inornatus intergrade in Nigeria; described races nigeriae (S Nigeria) and goodi (N Cameroon) not satisfactorily distinguishable from former and latter respectively. In addition, a number of other described races are too poorly marked to warrant recognition: thus, minor (upper White Nile and Bahr el Ghazal), fayi (Kenyan Highlands) and ngamii (L Ngami, in Botswana) merged with tricolor, micrus (SE Kenya) and tenebrior (Eastern Cape, in South Africa) with layardi, and peasei (Kitunga, in Kenya) with dodsoni. Ten subspecies recognized.