Influence of differently managed bush‐encroached sites on the large herbivore distribution in the Namibian Savannah

Abstract

AbstractBush encroachment is reported from savannah regions worldwide. Different management strategies are used to rehabilitate these areas. In this context, the mutual interaction between vegetation and large herbivore's distribution is evident. We studied effects of land management on vegetation structure in regard to encroaching species and the subsequent habitat use of two grazing (oryx, Oryx gazella L.; common warthog, Phacochoerus africanusGmelin) and one browsing (greater kudu, Tragelaphus strepsicerosPallas) herbivore species. We assumed that (i) cleared areas will be favoured by grazers and (ii) noncleared areas will be favoured by browsers. Specifically, we asked: Which factors determine the habitat use of these different feeding guilds? Consistently with our expectations, we found that warthog favoured sites with high grass cover. For oryx, surprisingly shrubs with a height of 80–150 cm influenced their distribution positively, whereas for kudu, only the interaction of site and grass cover was significant in our models. However, this was related to the occurrence of shrubs of 80–150 cm height. We conclude that the management of encroachers, resulting in differences in vegetation, did not influence herbivore distribution as expected. Other factors like human impact and vegetation cover among others are discussed as additional drivers of habitat use.