South Africa Works to Control Kruger's Elephant Population

Although culling is again on the table as one of several options for keeping the large and growing elephant population of South Africa's Kruger National Park in check, park officials say no culling will occur before next year at the earliest.

Culling, along with relocation and contraception, are alternatives spelled out in the new management strategy the National Parks Board approved in March to protect the ecosystem of the famed park.

Park officials said the plan for managing Kruger's elephants was based on consultations with elephant experts, scientists and wildlife managers from around the world. Unlike most African range states where elephant populations are just starting to recover from the poaching rampages of the 1980s, South Africa (along with Botswana, Namibia and Zimbabwe) reports large populations they fear will destroy vegetation crucial to the survival of small species. Since the moratorium on culling began in 1995, Kruger's elephant population has increased by approximately 1,300, to 8,870.

For many years as many as 500 elephants were killed each year, arguably to protect the park's biodiversity. The practice was stopped when it was acknowledged there was insufficient evidence to determine how a fixed number of elephants might affect the park. The new plan seeks to answer that question.

Under the new park plan, Kruger will be divided into six zones: two botanical reserves, two "high-impact" zones where the elephant population will be allowed to increase unrestricted, and two "low-impact" zones where elephant numbers will be limited so vegetation can recover. According to the plan, culling is a last resort, to occur only if sufficient relocation areas are not available. About 300 elephants must be removed each year from the park, which is fenced, to maintain the ecological balance, officials say.

Vegetation "indicators" will help determine how many elephants the park can sustain. "Each of these indicators," said Leo Braack, general manager of conservation development at Kruger, "whether they be baobab trees, percentage of canopy cover in the area, species and age structure of plants in an area, and several others, has been assigned a percentage [that] they will be allowed to change before we will get concerned." If further change is deemed to be detrimental, elephant numbers will be reduced.

Although moving elephants is preferable to culling them, the high cost of capturing and transporting the animals--and in some instances buying land for relocation--has limited the practice. Nonetheless, South African experiments in resettling family groups of elephants in new areas have been successful. Some elephants from Zimbabwe, where the high number threatens not only habitat but human communities, livestock and crops, have also been relocated. Several organizations, including the National Parks Board, are seeking funds for relocation projects.

Contraceptives are another alternative for slowing elephant population growth. Since 1996 researchers have been experimenting with two approaches to elephant birth control. In immunocontraception, female elephants (which are first tested by ultrasound to confirm that they are not pregnant) are injected with a vaccine derived from the proteins found in pigs' ovaries. The vaccine triggers the development of antibodies that prevent sperm from penetrating elephant eggs.

In a second method, the female is implanted with the hormone estrogen, which prevents her from going into heat, or estrus. The downside is that estrogen appears to cause significant hormonal disruptions in some animals.

Even so, while contraception technology is still in the early stages and not yet cost-effective, it may one day provide an answer for the elephants in Kruger.