The adult African elephant (Loxodonta africana) eats between 150 and 170 kilograms of food and drinks as much as 200 liters of water every day. Now imagine keeping 7,000 of those animals fed.
That's the task of the staff at Kruger National Park, a 2-million hectare reserve that stretches 350 kilometers along South Africa's border with Mozambique. The elephant's appetite has an enormous impact on the surrounding environment. With this in mind, Kruger's scientists calculated in the 1960s that the number of elephants the park could host without harming wider biodiversity was roughly 7,000. To keep the population at that level, they initiated an annual cull. Over the next 27 years, approximately 14,500 animals were killed.
In 1995, facing widespread condemnation, Kruger stopped culling elephants. Since then elephant numbers in the park have continued rising. By last year, they had become so numerous that officials from South African National Parks suggested reinstating the cull as one method for managing elephant populations.
It is not surprising that the proposal triggered an emotional and heated response, prompting South Africa's environment and tourism minister, Marthinus van Schalkwyk, to convene a round-table of scientists to discuss the matter. It's clear that sparks flew at that meeting. The minister's spokesperson said in a subsequent statement that Schalkwyk had been struck by the lack of consensus. "It was disturbing that scientists appear intolerant of each other's views," he said. Suffice it to say, he's still considering the issue.
Kruger's problems are part of a wider challenge being experienced across southern Africa, where elephant populations have been steadily growing for years. In Botswana, for example, there were 121,000 elephants in 2002, compared to 20,000 in 1979.
In November 2005, seven biodiversity and wildlife groups in South Africa signed an agreement acknowledging that elephant populations urgently need to be managed to protect the wider biodiversity of the country. "Individual animal protection and indeed single-species conservation where that species' survival is not threatened is a luxury we can ill-afford, given the pressing need to address biodiversity and ecosystem conservation," they wrote.
For scientists, the debate focuses on the best way to safeguard biodiversity. On one side of the debate are scientists such as Ian Whyte, who has been responsible for elephant research at Kruger for 20 years. He points out that the park's elephant population was stable throughout the culling era and that no other species were lost from the landscape during that time.
There are definitely other methods, such as relocation or contraception, that can reduce elephant populations, he wrote in Africa Geographic magazine in April. But in some circumstances these other options will not be possible. "In such a situation, culling may be the only way to achieve these biodiversity objectives."
On the other hand, researchers such as Rudi van Aarde, chief of the Conservation Ecology Research Unit at the University of Pretoria, say that cull supporters have misplaced their emphasis. "Culling focuses on numbers and not on the impact elephants have on biodiversity," he says. "Impact results from the way elephants use space and not from their numbers."
A better solution, van Aarde and others argue, is to give elephants greater scope for movement without hindrance from the fences that mark national park boundaries or from human settlements. The idea, he says, is to create megaparks that transcend national borders and link existing parks to allow elephants to distribute themselves more naturally. Several such parks are already in development, and he feels the weight of scientific opinion is swinging in this direction.
"It no longer is about culling or no culling," he says. "It is about making decisions and rolling out activities that will focus on the causes rather than the symptoms of the problem. Numbers merely reflect on the response of elephants to specific management activities, and these activities need to be managed so as to focus on the causes of the problem, such as artificial distribution of water and interferences with seasonal movements, and long-distance dispersal."