Wildlife species richness and densities in wildlife corridors of Northern Tanzania

Wildlife corridors are crucial for effective conservation in fragmented landscapes, yet these corridors are vanishing across Africa. In order to assess the relative conservation effectiveness of two distinct management areas linking Tarangire and Lake Manyara National Parks in Northern Tanzania, we assessed seasonal densities of wild and domestic species as well as species richness of large mammals over a 3-plus-year time period. Line distance sampling showed that livestock densities were considerably higher in a human-dominated area with little enforcement of natural resource utilization (Mto wa Mbu Game Controlled Area; CA) than in a Maasai pastoral area with stricter limitations and enforcement of natural resource utilization (Manyara Ranch; MR). Conversely, densities of most corridor-dwelling (giraffe, Kirk's dik dik, and ostrich) and migratory (Grant's gazelles, zebra, and wildebeest) wildlife species were mostly higher in MR compared to the CA. Large mammal species richness was about two times higher in MR than in the CA. Despite strong anthropogenic pressures on communal lands and natural resources, our long-term wildlife monitoring provides evidence of continued connectivity in the Tarangire-Manyara ecosystem. At the same time, we caution that continued land-use changes and illegal exploitation of wildlife resources severely threaten the functional connectivity of this ecosystem. Our comparative analysis highlights the conservation value of pastoral lands in East African savannahs, provided that additional stressors such as land-use changes and uncontrolled hunting of wildlife are restricted.