The authors say many conservationists have recognised that large carnivores should be kept apart from humans.

Durban - Half of Africa’s 30 000 surviving wild lions are likely to die off within the next 20 to 40 years unless they are fenced off from humans or protected more intensively.

This is the conclusion reached by a group of more than 50 wildlife researchers in a study published in the latest issue of the journal Ecology Letters.

The main author, Professor Craig Packer, of the University of Minnesota, concludes that the future of the king of the beasts in Africa is so bleak that fencing them off from human settlements may be the only hope for their long-term survival.

The article was based on studying lion population densities in 42 conservation areas in 11 African nations.

The researchers found that lion population growth rates were highest in South Africa and Namibia, as well as in parks which were fenced off, privately managed and not vulnerable to trophy hunting.

“Given current population sizes and recent trends, all of the fenced-off populations are expected to remain at or above their full potential for the next 100 years,” they said.

But less than half of the unfenced reserves in Africa were likely to retain more than 10 percent of their carrying capacity for lions for the next 20 to 40 years. This included most unfenced conservation areas in Kenya, Botswana, Tanzania, Uganda, Cameroon and Ghana.

The authors say many conservationists have recognised that large carnivores should be kept apart from humans, but the lion-proof fencing option was not used in several countries for aesthetic reasons, because of high costs, or because they did not want to cut off animal migration routes.

As a result, conservation agencies in east Africa and other areas had tried to promote human-wildlife co-existence projects or mitigate conflict by setting up buffer zones and compensation schemes.

“However, our analysis suggests that human-lion coexistence should only be considered in areas where large-scale megafauna and pastoralist migration precludes any form of fencing.”

Alternatively, the authors say the other option would be to fence people into protected enclaves inside some of the large wildlife areas such as the Niassa National Reserve in northern Mozambique.

Co-author Dr Luke Hunter said: “These findings highlight the severity of the lion conservation crisis today and the limited choices we have to ensure a future for this species.”

Hunter is the president of the big cat conservation group Panthera and also spent several years studying lions in the Phinda private game reserve in KwaZulu-Natal.

“No one wants to resort to putting any more fences around Africa’s marvellous wild areas, but without massive and immediate increases in the commitment to lion conservation, we may have little choice,” he said.

The authors estimate that lions have lost almost 75 percent of their previous range over the past 100 years because of conflict with cattle herders, farmers and developers.

“Yet not all lion populations have declined. The Serengeti lions (in Tanzania) have steadily increased over the last 50 years; populations have remained stable in several large South African national parks and numerous private reserves in South Africa and Zimbabwe have successfully restored lions to areas where they had previously been extirpated.” - The Mercury