A study on the postrelease behaviour and habitat preferences of black rhinos (Diceros bicornis) reintroduced into a fenced reserve in Namibia

Translocations and reintroductions are key elements for the population management of the critically endangered black rhino (Diceros bicornis, Linnaeus, 1758). In this study, we investigated the postrelease behaviour and habitat preferences of a black rhino starter group (n = 4) on the individual level. The animals were reintroduced to a fenced game reserve (87 km2) in North-Central Namibia 1 year prior to our study. We used camera traps and very high frequency (VHF) radiotelemetry to examine the animals' temporal and spatial behaviour over a period of 4 months at transition between wet and dry seasons. Our results underline a peak in drinking activity and waterhole visits occurring between 7 p.m. and 8 p.m. We found a shift in intensity in drinking activity during the period of the study. Satellite-based woody cover estimations only suggest positive correlations between the density of woody cover and favoured black rhino habitat types. Although the area seems suitable to facilitate breeding success of this starter group, it does not support a self-sustaining population. However, black rhinos were already successfully reintroduced to several additional fenced reserves in this region. The selective opening of fences in the future could help to enable genetic exchange between currently isolated groups of rhinos.