Habitat changes reduce the carrying capacity of Hluhluwe-Umfolozi Park, South Africa, for Critically Endangered black rhinoceros Diceros bicornis

Abstract

The Critically Endangered black rhinoceros Diceros bicornis occurs mainly in protected areas. Hluhluwe-Umfolozi Park, South Africa, contains a key source population for black rhino conservation, and declining population productivity has been attributed to negative habitat changes and a reduction in carrying capacity. As home range increase may be an index of declining habitat quality we determined the home ranges of the black rhino in the Park and compared these ranges with previous estimates. The average size of the home ranges during 1991–2001 was 23.07 ± SE 0.81 km², which is 54% greater than in the 1980s. Sex and the availability of water did not influence home ranges. Home ranges decreased in winter. Female:male ratios varied across the Park, indicating that one or both sexes may prefer specific areas. Changes in vegetation structure and composition may have caused rhino to maintain larger ranges in order to meet their nutritional requirements. Ongoing review of stocking rates, population performance (including indicators such as range size), and intervention strategies are necessary to manage black rhino in dynamic savannah ecosystems.