Disturbance and Habitat Factors in a Small Reserve: Space use by Establishing Black Rhinoceros (Diceros bicornis)

Abstract

Continued persistence of black rhinoceros (Diceros bicornis) will likely depend on the cooperation of many reserves and the application of metapopulation models to manage across reserves. The suitability of any reserve, however, depends on factors that promote and constrain occupancy. Constraining factors, particularly human disturbance, are of concern in small reserves because constraints have potentially greater effects, relative to reserve size, than in large reserves. We investigated landscape use by black rhinos at Zululand Rhino Reserve. South Africa, as a function of elevation, slope, patch type, areas burnt and factors associated with disturbance (distances to nearest water point, human settlement, boundary fence, and roads). Estimated home ranges consistently demonstrated avoidance of human settlements, fragmentation of home ranges and sometimes multi-modal core areas. Resource selection functions confirmed that use of areas increased with greater distance from human settlements (log-odds = 1.3831 ± 0.4623 [95% CI]) and from perennial water points (2.2859 ± 0.8261). Space use was greater for thicket (1.0072 ± 0.5775) and closed savanna (0.8656 ± 0.6153) than for other patch types. Managers who plan reintroductions of black rhinos should consider availability of forage and cover, disturbances that might restrict access to resources, and effects of reserve size on those disturbances.