We have fenced the wild areas in and with it the game that live there. We have disturbed the natural balance and elephant can no longer make their great migrations.

Elephants have few natural predators and live long lives. They eat about 300kg of vegetable matter per day - and Kruger alone has 12,500. This translates to 3,750 tons per day or 1.4 million tons per year

In Hwange where there are an estimated 30,000 elephant this translates to 9,000 per day and 3.3 million tons per year.

How can normal vegetation growth sustain that?

Following the "Big Elephant Debate" in Berg-en-Dal, some 50 scientists from South Africa, the rest of Africa and abroad got together to discuss elephants and biodiversity in South Africa’s national parks, and specifically the Kruger National Park.

The South African government finally concluded it would have to lift a moratorium on the culling of the native elephant to cope with its booming population.

Amid protest and expressions of relief environment minister Martinus van Schalkwyk announced the elephant had been a victim of its own success with numbers growing from 8,000 to nearly 20,000 in national parks and private reserves in just over a decade.

He unveiled a new conservation plan and stressed that the killing of excess animals would only be allowed once all other available options - including translocation and contraception - had been ruled out.

Contraception and translocation are both cost prohibitive - and who wants a 4-ton animal that is going to devastate your habitat? Hwange reportedly has 40,000 elephants and the same problem faces the authorities there.

He continued:

"Our department has recognised the need to maintain culling as a management option, but has taken steps to ensure that this will be the option of last resort that is acceptable only under strict conditions," he said in a statement.

"The issue of population management has been devilishly complex and we would like to think that we have come up with a framework that is acceptable to the majority of South Africans."

The UK Guardian reports that debate over culling is hugely emotive in South Africa, which is renowned for its wildlife, and the announcement came after nearly three years of widespread consultation and acrimonious debate.

Supporters of culling point to growing difficulties in managing elephants in the country’s biggest and most famous game reserve, Kruger National Park. It has more than 12,500 elephants, 5,000 more than is sustainable, according to park officials.

Elephants have huge appetites and reduce forests to flatland by uprooting trees and trampling plants as they feed and roam - threatening any park’s biodiversity.

But some conservationists argue the environmental impact is less severe than is being claimed, while animal rights campaigners, who have threatened to hold public protests if culling goes ahead, say the elephants’ intelligence and their close-knit social structures make culling deeply inhumane.

In 2005, the government recommended the cull of 5,000 elephants, which would have been the largest slaughter anywhere in the world, causing a storm of protest and a rethink. The new framework, which will permit culling from May 1, is likely to see a far lower number of the animals destroyed. Van Schalkwyk said that estimates of between 2,000 and 10,000 deaths were "hugely inflated".

A national park or private reserve will only be allowed to cull with the approval of the authorities and an elephant management specialist, who must be satisfied all other options are not viable.

These include contraception, a tricky process that can cause females much distress, and relocation of entire elephant families, which can be stressful for the animals and is expensive. The removal of fences between the Kruger and parks in neighbouring Mozambique will eventually help with migration into less congested areas, but not soon enough, according to some experts.

Rob Little, conservation director at WWF in South Africa, welcomed the announcement. He said the country’s rapid elephant population growth of 6% - mainly due to the absence of natural predators of mature animals - was unsustainable. If unchecked, wildlife officials say the elephant count will top 34,000 by 2020.

"All available options must be available to control the elephant population here and conserve the biodiversity of the national parks," said Little. "The new framework imposes a hierarchy of choices, and culling is right at the bottom. We are not going to see a mass destruction of elephants here."

But other conservation groups were less enthusiastic. "This does not give park managers carte blanche simply to go out and kill if they think they have too many elephants," said Christina Pretorius, communications manager at the International Fund for Animal Welfare. "It is incumbent on the government to make sure that this is policed properly."

Michele Pickover of Animal Rights Africa, which has threatened to urge a tourist boycott if culling goes ahead, said there was no scientific proof that the killing of elephants was necessary or even effective in controlling the population.

"This is a sad day for the country. Elephants are being treated as commodities by the government and game managers," she said.

The Kruger Park Times reported that Danie Pienaar, head of Scientific Services in the KNP. said that:

"We looked at the positive and negative roles of elephants in a system and tried to identify weaknesses and gaps in our existing management plans and identify where more work needs to be done."

Prof Rogers is an ecology professor at the University of the Witwatersrand who has conducted research in Kruger for the last 18 years, mainly focussing on rivers. He said there was broad agreement amongst the attendees that a decision about the elephants in South Africa’s protected areas needs to be made soon. If the situation is left as is, the elephant numbers in five years would probably reach 20 000 and in 10 years there would be about 30 000 elephants in Kruger.

In the past, elephant management decisions were largely based on carrying capacity. If carrying capacity is defined in terms of food only, the KNP could theoretically accommodate 50 000 to 60 000 elephants. However in recent years, scientific focus has moved from big species to biodiversity, a more holistic view. The "carrying capacity" at which biodiversity is maintained will be much lower than a food related "carrying capacity" but scientists do not have a good knowledge of the biodiversity consequences of elephant impacts at this stage.

The group agreed that too many elephants in the KNP can have a detrimental impact on the biodiversity.

The impact of elephant on biodiversity is context specific so that the impact on the vegetation in Kruger, for example will differ from that in Addo and again from that in Tsavo. In Kruger the structure of the trees could change over time from large trees to shrubs and this, in turn, will have a knock-on effect, as some 40 percent of Kruger’s bird species are dependent on tall trees for some part of their life cycle.

Many scientists feel that elephant numbers in Kruger are already too high but others say that elephant will always eliminate some species so that the real question is at what stage does it matter. "This brought the delegates to the next major point of agreement and that is the need for an adaptive management approach," says Prof Rogers. "Essentially this means learning by doing."

The workshop expressed its high regard for Kruger’s present adaptive management plan and recognised Kruger’s management objectives as ranking with the world’s best. The meeting agreed that a fixed number, e.g. 7000 elephants for a reserve, is unnatural as elephant numbers will always fluctuate in nature.

Unfortunately South Africa’s national parks are too small for these fluctuations to take place naturally and the need for an adaptive management approach is apparent. They felt that there was a need to do something sooner rather than later. If something is done now, it will take about five years before the effect is noticeable. The group agreed that with new ideas developed in the workshop, they could produce estimates within six to nine months of how soon and how much effect the elephant population can have on Kruger’s biodiversity.