Avian diversity and assemblages around Ruacana Waterfall, north-western Namibia.

Abstract

In 2011-2012, the line transect method was employed to study avian assemblages in the Koakoland (Mopane) Savanna around the Ruacana waterfall in the Kunene Region, north-western Namibia. In total 64 resident species were recorded, a number which was high in comparison with other bushy habitats. Simpson’s Diversity Index was also high (S = 0.96). Group of dominant species (32.4%) comprised Streptopelia capicola, Tockus erythrorhynchus, Plocepasser mahali, Pycnonotis nigricans and Lanioturdus torquatus. The following species recorded as resident around Ruacana Waterfall were endemic to Namibia: Poicephalus rueppellii, Phoeniculus damarensis, Lanioturdus torquatus, Tockus damarensis and Parus carpi. Although the difference between the riparian and dry variety of the Mopane Savanna was insignificant in terms of biodiversity (S = 0.97 and S = 0.92 respectively), the number of species in dry bush was much lower than in the riparian bush ( 2-test = 4.76; p < 0.05). Also the S¨orensen similarity coefficient was unexpectedly low between the two habitat varieties (I = 0.48).