AFRICAN elephant populations are staging a remarkable recovery after a ban on the sale of ivory was imposed to tackle their slaughter.

Over the past decade, the animals have come back from the extinction danger zone, according to the latest research.

The number of savannah-dwelling elephants in major populations in eastern and southern Africa has increased substantially, a study by the African Elephant Specialist Group of the World Conservation Union (IUCN) shows.

Estimated numbers have increased from about 283,000 in 1990 to nearly 355,000 in 2002, which translates to an overall rate of increase of around 4.5 per cent per year. It is the first comprehensive statistical analysis of changes in the elephant population ever conducted at this scale.

However, although the 49 sites selected in the study - 38 from six countries in southern Africa and 11 from two eastern African countries - includes approximately three-quarters of the known elephant population in Africa, and an even higher proportion of the continent's savannah elephants, researchers stress that their findings do not apply to all elephant populations.

Julian Blanc, one of the authors of the report, said: "Most populations in west and central Africa - where virtually all of the continent's forest elephants live - have only been surveyed formally once or not at all, and it is therefore impossible to assess trends at the continental level at this stage."

Some conservation organisations have now expressed worries that the significant increase in animals will lead to a huge increase in pressure to end the ban on the international trade in ivory.

The ban was put in place in 1989 to protect rapidly dwindling elephant numbers.

But at a meeting of the Convention on International Trade in Endangered Species of Wild Flora and Fauna in 2002, Namibia, Botswana and South Africa were granted permission for one-off sales of stockpiled ivory, provided certain conditions were met. These sales have not yet taken place.

At the last meeting, in October 2004, the ban was upheld, despite efforts by Namibia to gain permission to export 4,400lbs of ivory a year.

Callum Rankine, head of species officer at the WWF, the conservation organisation, said: "Populations of elephants in southern Africa are healthy but in west Africa, central Africa and all of Asia they are far from healthy.

"Conservationists are afraid that if there was a legal international trade in ivory, that could lead to an increase in the illegal trade. Populations of elephants outside southern Africa could not stand that. It's not something we want to see."

The estimated increases in elephants were greatest in southern African sites, with an average rate of growth of around 5.5 per cent per year in the period covered by the study.

Populations in much of the southern African continent are believed to have been increasing throughout the 1990s from a population minimum in the early part of the century.

The continuing increase is not necessarily good news for southern Africa, where the high population densities of elephants are having a considerable impact on their habitats in many parks and reserves. The worry is that the rate at which they consume vegetation is too quick for it to replenish itself.

Farmers also complain that the elephants destroy their crops, which experts believe may lead to conflict with the animals. This has resulted in increasingly widespread calls for population control measures to be reinstated in the form of an annual cull to keep numbers at more manageable levels.

All elephants have an inefficient digestive system and absorb only about 40 per cent of what they eat. They have voracious appetites, and estimates in the wild range from 100lb to 1,000lb of vegetation consumed per day, 16 hours of which are spent feeding.

The wild elephant is also a destructive eater, uprooting and scattering as much as is swallowed, often breaking down whole trees. Elephants eat almost anything green, but grass, shoots and buds of trees and shrubs are preferred.

Farms are often raided for fruits and vegetables. Average daily consumption of water for fully grown animals is between 30 and 50 gallons.

Although the study results for east Africa are less clear cut, the evidence also suggests an increase, with the estimated rate of population growth hovering about 2.5 per cent per year. This also indicates the ongoing recovery of major elephant populations in the area, many of which were decimated by poaching and drought throughout the 1970s and 1980s.

Jean-Christophe Vie, of IUCN's species programme, said: "Although elephant numbers may be up in the eastern and southern regions, we cannot assume the situation to be the same in other parts of Africa. There is no hard data for central and west Africa, but reports indicate that poaching for bush meat and ivory is prevalent in many areas, including several national parks, particularly in central Africa."

Some of the data presented in the study has now led to the "downlisting" of the African elephant in the IUCN's Red List of Threatened Species, from the previous category of "endangered" to the current status of "vulnerable".

Man tries to make up for terrible record

JAMES REYNOLDS

ALTHOUGH humans are largely responsible for the continuing extinction of species all over the world, we have also managed to bring many back from the brink.

The black-footed ferret, Mustela nigripes, was listed as extinct in the wild in 1985 when the last known population in north America fell foul of a canine distemper epidemic.

To save the species, the remaining 18 were taken into captivity and a breeding programme begun. Since 1987, about 5,000 have been born in captivity, with some 1,800 released.

The American bison, Bison bison, had a population in North America of between 30-60 million about the time modern man arrived. This was reduced to about 1,650 by 1903. However, its numbers are now back up to more than 350,000 with populations reintroduced into many public and private parks and preserves in the United States and Canada. It is now believed to be globally secure from extinction.

The southern white rhinoceros was widespread throughout southern Africa in the early 19th century.

However, by the turn of the 20th century, all that remained was a relic population of between 20 and 50 rhinos in the South African Umfolozi game reserve.

By 1960 there were at least 700 animals, and today, after intensive conservation efforts, there are more than 11,500 distributed between 250 populations in seven separate countries.