Hundreds of elephants in Botswana are mysteriously dropping dead next to watering holes

• Warning: This article contains images of dead elephants which some may find upsetting.
• More than 350 elephants have been found dead in Botswana due to mysterious causes, according to UK conservationist organization National Park Rescue.
• They told Business Insider that it is unlikely — but not impossible — that poachers or anthrax are to blame. It could also be another, as-yet-unidentified disease.
• In some cases, elephants have died on their faces, and others have been seen wandering in circles and dragging their back legs, suggesting a neurological problem.
• Botswana is home to Africa's largest population of elephants, but their numbers are in decline.

Hundreds of elephants are suddenly dying in Botswana, in circumstances that conservationists are struggling to explain.

Mark Hiley, co-founder of UK-based charity National Park Rescue, told Business Insider that his colleague had seen more than 350 elephants dead in the Okavango Delta in northern Botswana since early May.

"As far as the scale is concerned, it's the biggest thing that's happened to elephants this century," he said.

Dr Niall McCann, director of the trust, described to the BBC how, in a single three-hour flight over the delta, he spotted 169 carcasses.

Around 70% of them were near watering holes, The Guardian reported, citing locals who wished to remain anonymous. Elephants of all ages and sexes are dying, and some of those alive appear weak and emaciated, the paper said, citing local reports.

Botswana is home to Africa's highest population of elephants, but numbers are in steep decline, according to the World Wide Fund for Nature. They are drawn to the grassy Okavango Delta, which floods seasonally.

There is currently no explanation for the deaths, although several theories are being considered.

Cyanide poisoning by poachers would be a possibility, said Hiley. But, he said, none of the tusks have been removed from the creatures. Vulture carcasses, poisoned from feeding on the bodies, would also normally be seen in that scenario, but they have not seen any.

Additionally, cyanide's potency dissipates rapidly over a period of 24 hours, he said. The scale of the deaths here suggests a longer-lasting poison.

Anthrax and drought killed more than 100 elephants in 2019, according to African news site The Southern Times. But this possibility is also unlikely, Hiley said, because of the uncharacteristic position the bodies have been found in.

An unknown pathogen is also a potential answer. Hiley said that COVID-19 is exceptionally unlikely as there are no cases for almost 800 miles.

"Some of the elephants are running around in circles, others dragging their back legs, suggesting the potential for toxins affecting brain function," he said in comments emailed to Business Insider.

Without test results, the answers are difficult to pinpoint. Botswana's government has not yet carried out tests, and conservationists are dismayed at the delay.

Dr Cyril Taolo, acting director for Botswana's department of wildlife and national parks, told the Guardian that tests were under way, and that the department had confirmed 28o of the deaths. The results would take two or more weeks, he said, adding that COVID-19 restrictions have posed delays.

National Park Rescue said the situation is being handled poorly.

"A professional team needs to go in fast and the government are not allowing that," Hiley said in his emailed comments. "They're turning down offers of support, which is very unfortunate. And there's no doubt that the lack of cooperation is causing more elephant deaths."

"It's a tragedy given that they're one of the most persecuted species on the planet," he added.

Business Insider has contacted the Botswanan government for comment, but did not immediately receive a reply.