July 1 (UPI) -- More than 350 elephants have died in Botswana within the past two months in what experts have described as a "conservation disaster."
Niall McCann of British charity National Park Rescue said his colleagues first discovered 169 dead elephants in early May during a 3-hour flight over the Okavango Delta in Botswana, the southern African country which is home to one-third of the continent's elephant population.
"To be able to see and count that many in a 3-hour flight was extraordinary. A month later our, colleagues did another flight over and spotted 187 new carcasses, bringing the total to over 350," McCann said. "This is totally unprecedented in terms of numbers of elephants dying in a single event unrelated to drought."
Acting director of Botswana's department of wildlife and national parks, Cyril Taolo, said the government has confirmed 280 deaths and has sent samples for testing but said COVID-19 restrictions have delayed the process, so causes for the deaths are not yet known.
Poisoning or an unknown pathogen are considered the most likely possibilities as the government has ruled out anthrax and poaching, noting the tusks had not been removed.
Male and female elephants of all ages have died and witnesses have said some were seen walking in circles, indicating possible neurological impairment, while others have appeared weak and emaciated, suggesting more forthcoming deaths.
"If you look at the carcasses, some of them have fallen straight on their face, indicating they died very quickly. Others are obviously dying more slowly, like the ones that are wandering around. So it's very difficult to say what this toxin is," McCann said.