Managing African Elephant Populations: Act or let die

Abstract

During the last century, the number of African elephant (Loxodonta africana) declined dramatically as a result of over-hunting, poaching for ivory and, more recently, the loss of habitat area due to encroachment of the human population. In some areas, however, the trend to declining numbers was reversed after the elephant was placed on Appendix 1 of the Convention for International Trade in Endangered Species (CITES) and a worldwide ban was imposed on the sale of ivory. Unfortunately, the resulting recovery in elephant numbers within both National and privately owned game parks poses a threat to the survival of many other species. Indeed, when elephant numbers exceed the carrying capacity of a game park, the gradual destruction of vegetation and habitat is catastrophic and, if left unchecked, is only arrested when the elephants themselves begin to die of starvation. Over the last 30 years, it became generally accepted that the best way to prevent this boom-and-bust scenario and, in addition keep epidemic diseases under control, was to maintain elephant numbers below the carrying capacity by culling. During the 1990s, however, popular opinion turned against culling as a means of controlling elephant populations and the focus shifted instead to translocating animals from areas of high to areas of low population density. Self-evidently, while relocation may be a useful way to control elephant numbers in relatively small parks, it is unrealistic to expect to relocate thousands of animals per year to keep the population under control in the large parks, for example, in northern Botswana. Of course, the best method for controlling population growth depends critically on the size and rate of growth of that population and, in this respect, it has been proposed that contraception may offer an alternative to relocation or culling in relatively small parks with a limited number of elephants. However, while the first experiments to examine the efficacy of immune contraception in female elephants have offered promising results, and preliminary experiments to modulate the behaviour or fertility of bulls have also begun, there are as yet no agents proven to be reliable, effective in field conditions and without significant side effects. The aim of this workshop is to discuss the current policies for controlling elephant numbers and to assess the suitability of newer strategies being developed to address this problem. Given the increasing interest in pharmacological means of controlling population size, it is hoped that experiences with various compounds in other species may help to indicate the approaches most likely to be applicable to the African elephant. It is also hoped that this workshop will stimulate collaborative research projects to identify the best approach to population control in a given situation, and to develop the means to implement that plan safely and effectively. This information may come to provide a valuable source of support when the management decisions required to ensure the health and viability of a game park and its elephant population are complicated by politics.