South Africa plans to move up to 500 rhinos from its flagship Kruger National Park to counter a wave of poaching of the animals for their horns, highly prized in newly affluent Asian countries as a sign of wealth.
Officials said on Tuesday the mission could see some of the animals shipped to nearby Botswana and Zambia as South Africa grapples with a poaching epidemic that has seen more than 630 rhinos killed so far this year, 408 of them in Kruger.
"We have to take rhinos to where they are safe," Markus Hofmeyr, head vet of the national park, told a news briefing.
The latest census from the Kruger shows it has between 8,400 and 9,600 white rhinos. Despite the poaching, the population has stabilized with an annual mortality rate, including poaching, of around 8 percent matched by an 8 percent birth rate.
The removals will be a huge operation that will involve tracking down the animals in rugged and remote bush and then darting them with tranquilizers from helicopters. Moving one animal could cost $1,500 or more.
"It is a mammoth task. We are looking to numbers of up to 500," Environment Minister Edna Molewa told Reuters. "We must start soon."
Kruger rangers move some rhinos every year, with park management using the proceeds from sales to private reserves to help fund conservation efforts.
A record 250 rhinos were moved in 2009 but the scale of the poaching problem had forced it to take a more drastic approach, Hofmeyr said.
The focus of the operation will be on Kruger's eastern border with Mozambique, one of the world's poorest countries, where poachers from impoverished communities are lured by the promise of quick money.
Botswana in particular may be an ideal base for the relocated rhinos because it has vast areas of sparsely populated and inaccessible wilderness.
South Africa is the epicenter of a surge in poaching over the last few years because it is home to the vast majority of the world's population - 18,000 white rhinos and 3,000 black rhinos.
More than 1,000 were poached last year, three times the tally in 2010, to meet soaring demand for rhino horn, coveted as an ingredient in traditional medicine in fast-growing economies such as China and Vietnam.

According to the Convention on International Trade in Endangered Species, which monitors trade in wildlife products, there has also been a shift from medicinal use to flaunting rhino horn as a sign of wealth.

Its street value is estimated by some conservationists at $65,000 a kilogram, making it more valuable than platinum or gold.

Elsewhere in Africa, elephants are being poached at an alarming rate for the ivory in their tusks, while another species, the pangolin - a kind of anteater - is hunted because its scales are a prized fashion product and its meat a delicacy.