A conservation model for black rhino

Over the past thirty years the black rhinoceros (Diceros bicornis) population in Africa has declined from about 65000 to 3500. In contrast the South African and Namibian population has increased four-fold to 1000 over the same period. The recently developed national conservation strategy for black rhino has as its main goal a further four-fold increase in the current population in as short a period as possible. To achieve this, the growth rate of the population as a whole will have to be maximised. This involves removing animals from areas where the population is approaching the ecological carrying capacity and establishing new viable populations in other suitable reserves. A model, incorporating what is known about the population biology of black rhino, was developed to give guidance to managers on the most appropriate harvesting strategy to adopt for their populations; in particular, to determine the rate of removals and the age and sex of individuals to be removed to attain the conservation goal as soon as possible.