The status of the genus Hyperolius Rapp 1842 (Amphibia Anura Hyperoliidae) in Ethiopia

Four species of Hyperolius Rapp 1842 are recognised in Ethiopia, two of which have not previously been recorded from this country: H. viridiflavus (Duméril & Bibron 1841), with which H. heuglini Steindachner 1864 and H. destefanii Scortecci 1943 are considered to be conspecific; H. nasutus Günther 1864; H. balfouri (Werner 1907), including H. zavattarii Scortecci 1943 as a synonym; and H. kivuensis Ahl 1931, represented by the subspecies bituberculatus Ahl 1931. The author agrees with SCHIØTZ (1971, 1975) that many (perhaps most) named populations of H. viridiflavus do not represent true subspecies, but argues that the only correct way to create nomenclatural distinctions between phenotypes that are acknowledged to be of infrasubspecific rank is by the use of varietal names. Three such varieties, each showing at least some indication of geographical and ecological isolation from the others, are believed to be present in Ethiopia: viridiflavus, pachydermus (Werner 1907), and a third form to which the name destefanii is provisionally assigned. If further species of Hyperolius, including perhaps undescribed endemics, await discovery in Ethiopia, they are probably few in number and most likely to be found in the still poorly-explored southwestern sector of the country, where humid savannas and lowland forest provide an abundance of suitable habitat. Elsewhere, even H. viridiflavus shows little capacity to extend beyond moderate elevations on the central plateau, and the genus is probably excluded from most of the surrounding lowlands by intolerable aridity.