Anuran surveys in south-western Nigeria

We report on the results of amphibian surveys in three south-western Nigerian states: Lagos, Ogun and Oyo. In total, we recorded between 35 and 38 species. The number of species per state ranged from 22 to 29. Most species were typical farmbush or savanna frogs. Although the overall species richness was comparatively low and only a few species were forest specialists, we observed a surprising number of frogs that could not unambiguously be assigned to described species. This was especially true of the genera Leptopelis and Phrynobatrachus. Whereas some of these taxa (Leptopelis cf. macrotis, Phrynobatrachus cf. liberiensis) seem to indicate closer relationships between south-western Nigeria and the Upper Guinea forests, other findings (the eastern variation of Phlyctimantis boulengeri, Nectophryne afra) indicate the opposite geographic relation. The position of the study sites between the diversity hotspots of Upper and Lower Guinea would suggest high anuran diversity. We failed to record such a high diversity, but possibly found species from both areas and probably undescribed taxa (Phrynobatrachus sp., Leptopelis sp.). We believe that the high amount of degraded and converted natural forests may have already resulted in an impoverished anuran fauna. Remarkable and even new species may have survived in some of the small remaining forests. Intensive surveys and sustainable conservation of the remaining forests of south-western Nigeria is therefore highly recommended.