There is a possibility that many of the 36 parks in the proposed area could open to each other across borders, although the parks are in various states of repair.
But the core idea, Van Riet said, is that member countries would promote conservation of shared wildlife and socio-economic development through ecotourism and related activities such as jointly regulated safari hunting.
At a ceremony at Victoria Falls last year, ministers of environmental affairs and tourism from the five countries signed a memorandum of understanding committing their governments to work toward establishment the shared parkland.
But residual landmines pose a major obstacle to the project, particularly in Angola, which suffered nearly four decades of anti-colonial and civil war that ended in 2002.
The proposed conservation area would skirt Cuito Canavale, a town that in 1988 saw the bloody closing battle between South African troops and the Cuban-supported fighters of Angola's now-ruling MPLA party.
Van Riet said the landmines seem concentrated mainly along a 50-mile (80-kilometer) strip of the Cuando River, which in places divides Angola and Zambia. Most Angolans from the area now live on the Zambian side of the river.
"I don't know of any plans yet to lift the mines," he said. "Outside help and money is going to be needed to do it."
Lucas Gakale, secretary to Botswana's ministry of environment, wildlife, and tourism, said the scheme could still significantly ease the pressure on his country's large elephant population.
"A plan we drew up in 1990 put the maximum number of elephants Botswana could carry at 60,000. But because culling was controversial, and because we did not want to attract international condemnation, we allowed numbers to grow," he said. (Related: "South Africa May Kill Elephants to Manage Populations" [March 1, 2007].)
"[The population] is now put at up to 150,000, and we need somewhere for the animals to go," he added.
"Zambia and in particular Angola offer a way out. We are in fact already seeing elephants move into Angola. They seem to sense where the mines are because they pass them by."
Gakale chairs the five signatory countries' officials committee, which is responsible for taking the KAZA process forward. He said the next step is a full feasibility study.
But more urgently, he said, the individual governments must start talking with the local communities that stand to be affected.
The countries should start negotiations with local authorities and immigration, security, and disease-control establishments, he added.
"We are going to try to open adjoining parks across national boundaries and link others by corridors. We will need to do it in a way that will avoid large-scale resettlement," he said. "But the biggest challenge is going to be to get the cooperation of the various land users."
Werner Myburgh is the Peace Parks Foundation's project manager. He said only about 2.5 million people are estimated to live in the proposed parkland, which adds to its potential for being developed into an enormous protected area.
Angola's 76,832-square-mile (199,049-square-kilometer) Cuando Cubango province would make up a major portion of the proposed parkland.
After decades of war, the province today has only about 140,000 residents.
The conflict also took a heavy toll on the area's wildlife. Elephant ivory paid for weaponry, while other wildlife became bush meat for soldiers and famished villagers.
Myburgh said he recently flew over the area. "There were hardly any huts to be seen and no roads. I thought to myself, this is wild Africa, without game."
Cleared of minefields, he said, the area could offer a vast new home for Botswana's elephants.
Overall, Myburgh has high hopes for the ambitious project.
"The ministers involved are young, enthusiastic, and energetic," he said. "The political will exists, and there is the expertise and the funding coming in to see it through."
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