Mindje, M., L. Tumushimire & U. Sinsch

Diversity assessment of anurans in the Mugesera wetland (eastern Rwanda): impact of habitat disturbance and partial recovery. pp. 27-38

Abstract. The Mugesera wetland, one of the key wetlands of Rwanda, has been subjected to substantial habitat alteration during the past decades. We studied the resulting impact on the anuran diversity, carrying out bioacoustic and visual surveys in six microhabitat types near Gashora for eight nights (three replicate surveys each) during the rainy season of 2018. The diel calling activity of anurans varied significantly between species and microhabitats. We detected twelve anuran species: Afrixalus quadrivittatus, Amietia nutti, Hyperolius cinnamomeoventris, H. kivuensis, H. rwandae, H. viridiflavus, Kassina senegalensis, Phrynobatrachus kakamikro, P. natalensis, Ptychadena nilotica, Sclerophrys regularis, and Xenopus victorianus. Except for the habitat specialist H. cinnamomeoventris all species are generalists, occupying all available microhabitat types independent of former or present degrees of disturbance. Partial regeneration of the natural vegetation (papyrus reed community) following massive human disturbance in the Mugesera wetland did not shift the species composition of local anurans towards that of a primary swamp community. Variation of local alpha-diversity followed closely the predictions of the Intermediate Disturbance Hypothesis. Hence, the Mugesera wetland currently constitutes a secondary papyrus swamp with an amphibian community indistinguishable from that of cultivated swamps.

Key words. Amphibia, Anura, bioacoustic, advertisement call activity, impact, degradation, wetlands renaturation, season, hour of the day, microhabitats.