Effects of landscape context on mammal richness in the urban forest mosaic of EThekwini Municipality, Durban, South Africa

Abstract

The loss and fragmentation of natural habitats is a major threat to biodiversity globally. In fragmented landscapes, species are not only affected by patch-level attributes but also by the influence of the whole mosaic of landscape elements surrounding habitat patches. Therefore, it is important to understand the simultaneous effects of local and landscape-level attributes on biodiversity. In this study, we determined the influence of landscape context on species richness of forest mammals in an urban-forest mosaic of the EThekwini Municipality Area, Durban, South Africa. We determined presence/absence of mammals in 28 patches using remote-triggered camera traps over two sampling periods. We applied generalised linear modelling within an information-theoretic framework to quantify the effects of within-patch, isolation, matrix, and landscape level attributes on species richness. The results showed the importance of landscape context for occurrence patterns of mammals in fragmented landscapes. In particular, they showed that patch size, shape complexity, habitat amount in the immediate environment, habitat proximity and road density were the most important factors influencing mammalian richness patterns. Overall, the results stressed the importance of habitat area (patch size, habitat amount in the immediate environment, and habitat proximity) and its spatial configuration to faunal preservation and suggest that management efforts in this landscape should be aimed at protecting fragments from further loss and disturbance and matrix improvement to increase landscape connectivity.