AFP

ELEPHANTS have become such a pest in South Africa that the government wants to shoot some. That looks like a victory for conservation, albeit a bittersweet one. Almost 20 years ago the population of the African elephant was collapsing and the world banned the ivory trade. If today there are enough elephants to shoot, isn't it time to rescue the rhinoceros and save the tiger and countless other endangered species, by redoubling the effort and getting the ban on trading them to work too?

Not if you care about wildlife, it isn't. That is partly because the story of the elephant is not all it seems, and partly because the best way to save a species is to make it valuable to people who may have other uses for the land. Although short-term bans can give a breathing space to species in the direst straits, in the long run they will not save anything. They may even make the situation worse.

The collapse in elephant numbers during the 1980s mostly took place in Tanzania, Zambia, Sudan and what was then Zaire. They seem to have resumed their fall across large parts of Africa—indeed, one expert told America's Congress this week that the illegal ivory trade is increasing. In some parts of Africa poaching is now as bad as it ever was (see article). In Botswana and South Africa, where elephants thrive today, they thrived before a ban existed. It is hard to argue that stopping the ivory trade has permanently transformed the elephant's future.

Other trade bans offer an equally pessimistic lesson. In the past few decades, the black rhino has become extinct in 18 countries where they were common, and populations have fallen fast in many others. The message is the same with the tiger and the Yangzi river dolphin. Even when a ban coincides with a fall in consumption, as with ivory, demand—and thus poaching—has a habit of coming back.

The idea of a ban is seductive, because it mobilises public support in rich countries and it can be shackled to a campaign to reduce demand. Yet bans have many shortcomings. They are vulnerable to the constant need to spend money enforcing the restrictions on trade. Poaching is hard to control and is usually a low priority for the police and the army. And if demand remains rampant, as with rhino horn and tiger bone, prices rise and the ban becomes a way for illegal traders to make a lot of money. In recent years the business has increasingly involved gangs of criminals that are almost impossible to eliminate. Better forensic techniques are helping to track down the sources of some wildlife seizures, but corruption and inertia mean that successful prosecutions are rare.

Moreover, species are dying off for many reasons—trade is not even the most important. Wildlife is threatened by the loss of land, fragmentation of habitats, deteriorating ecosystems and invasive foreign species. Something as blunt as a trade ban is poorly equipped to sort all of that out. For instance, the leopard and Goffin's cockatoo are seen as pests by local people in sub-Saharan Africa and the Indonesian island of Tanimbar. A trade ban means that endangered animals have no value. That encourages landowners and land users to kill the animals or to allow them to be killed or to die off through neglect.

A better policy is to make wildlife more valuable to man, not less. One way that suits everybody is tourism. The gorillas in the Virunga mountains of Rwanda attract a lot of money from visitors. They are doing well, unlike their cousins over the border in Congo which do not earn their keep, and are prey to hunters who want to clear them out and take their land. Tourism is one way to help the Indian tiger, which is much rarer than people thought.

A second, less popular way to make money is to exploit animals sustainably. Killing individual creatures need not harm populations. Many animals may be farmed or ranched to create a valuable legal trade. That is what has happened with the vicuña, and with crocodiles and their kind. Rhino horns can be cut off without even killing rhinos.

The cull of the wild

Yet the potential for sustainable exploitation is untapped. Although governments, greens and consumers have embraced the sustainable use of resources, including wildlife, the killing of large, attractive species keeps being shelved at the meetings of CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Animal-welfare groups are more concerned with harm to individual animals than with the survival of entire species, so they do not want any animals killed at all. Conservation groups worry that sustainable killing is hard to sell to their members. A disappearing species is good for fund-raising; blood on your hands is not.

Sustainable exploitation is not easy and it will not always work. To start with, you need a valuable product. You need the rule of law and government backing. Local people must feel secure in their ownership of the animals and what they produce if they are going to put in the effort to manage and protect them. But exploitation has a crucial edge over straight bans: it earns money. And that is why it can save animals.