Namibia is asking for bids for the wild animals, saying the country has too many, and citing increasing conflicts with humans.
Any foreign buyers must show they can offer quarantine facilities and have permission from conservation authorities in their home country, authorities insist.
But wildlife experts, alarmed by the auction, say the country’s elephant numbers are in decline, and these populations are “transnational” – they pass through the country, so are not Namibia’s to sell.
Last year, wildlife chiefs shot 10 elephants that had moved into farming areas, destroying crops during harvest season.
Before Friday’s auction was planned, stakeholders had agreed to keep elephants away from crops by creating electric fencing, elephant corridors and water points at a distance from villages, AllAfrica.com reported, but the government said it was not aware of the suggestions.
National Park Rescue, a charity protecting African parks from poaching, says it fears the sale may be a way to justify an already planned cull, with lucrative hunts and ivory already sold to hunters, or that the government may have already lined up a sale of the animals to a game reserve, with claims of crop-raiding an excuse.
The Zimbabwe-based and UK-registered charity says it also suspects the sale may be a move to bolster votes from elephant-hating farmers; or that the sale is about clearing land for cattle farming groups or oil companies.
Namibia was the only country with a significant elephant population that refused to take part in an Africa-wide “Great Elephant Survey” of 2016, but its numbers are estimated at 23,000.
A coalition of 60 wildlife organisations, scientists and vets last month appealed to Namibia’s authorities to abandon the sale.
Born Free’s head of policy Mark Jones said: “These sentient, sensitive and highly social animals need protecting. Selling some of them off to private bidders will cause immense animal suffering, and disrupt their remaining family groups and herds.
“These proposed sales will do nothing to manage populations or mitigate conflict between elephants and people. Indeed, the disruption to elephant family groups and wider elephant society could make conflict with people much more likely.
“There is also no indication of where the animals will end up; some could be exported to captive facilities which are completely unsuitable for wild elephants.”
NPR says Namibia has overestimated its elephant numbers. “Exaggerating population statistics and human-wildlife conflict helps governments create a range of revenue-generating initiatives including high hunting quotas, sales to zoos and hunting farms, and ivory-generating culls,” it says.
“The elephants NGov [the government] is trying to sell are actually in rapid decline.”
Last year more than 350 elephants were found dead around water holes in neighbouring Botswana. Toxins from algae were blamed.
Elephants are now extinct in 29 African countries and those trying to survive are “under increasing threat from the ongoing explosion of human populations, poaching and government greed”, NPR says.
“Around 95 per cent of Africa’s elephants have been slaughtered in 100 years and 10 per cent of survivors are killed annually. This auction is being seen by conservationists as a serious crime-against nature.”