Mystery Deaths of Elephants in Botswana Raises Concerns

Just north of Botswana’s world-famous Okavango Delta, it was lush and green as the summer rains tapered off and the air began to cool, but something wasn’t right. Savanna elephants, weighing as much as seven tons each, stumbled and staggered and walked in circles. Their heavy legs weakened as they struggled to take another step. One by one, they collapsed, many falling chest-first.

The first cluster of 44 elephants died in March 2020. By mid-June, conservationists had counted more than 350 carcasses scattered across the remote, roughly 3,000-square-mile region. By the following January, the number of mysterious deaths surpassed 450.

“There was a very foul smell,” says Davango Martin, the former manager of Kadizora Camp, a tourist lodge in the area. He was driving through the grounds in early May when he first noticed the stench and came across an elephant carcass splayed in a thicket of bush. “It was all rotten and nothing had actually eaten it—only maggots.”

Any loss of African elephants is alarming. Their numbers have plunged from an estimated million in 1979 to approximately 415,000, driven down by decades of ivory poaching, shrinking habitat, and confrontations with humans. Botswana, with some 130,000 elephants, is considered one of their last strongholds, so the mysterious deaths of hundreds made international news. 

In September 2020, under intense international pressure from concerned conservationists, Botswana authorities announced that they’d identified the culprit: cyanobacteria neurotoxins. Poisons released by blue-green algae that bloom in stagnant, nutrient-rich water, cyanobacteria neurotoxins attack the nervous system if ingested. 

However, a 14-month review of documents and interviews with investigators by National Geographic has found that much of the evidence leading to that diagnosis was unreliable—and that the Botswana government missed crucial opportunities to complete a timely and thorough investigation. 

Several outside experts, as well officials at labs that conducted analyses for the government, say tests for various possible causes of death—including cyanobacteria—were inconclusive and the evidence was degraded and mishandled, raising concerns that whatever killed the elephants could emerge as a threat again.

Mystery has shrouded the deaths from the very start . . .  

The tusks were intact, ruling out poaching. Vultures and other scavengers that fed on some of the carcasses didn’t appear to have died of illness. Nor did the cattle and zebra that drank from the same water holes, making poisoning seem unlikely. And the elephants’ strange behavior didn’t clearly match any known disease.

The elephants died in remote areas that were hard to reach, especially during the COVID-19 pandemic, which may partly explain why months passed before Botswana’s Department of Wildlife and National Parks sent a full team to recover tissue samples from the carcasses. But the department ignored or dismissed multiple offers from individuals and organizations to search for fresh carcasses and collect samples quickly, according to experts whose offers for assistance were refused.

“We had the opportunity to thoroughly investigate the cause of these mortalities and manage potential future episodes,” says Erik Verreynne, a wildlife veterinarian and consultant based in Botswana’s capital, Gaborone, who was not involved in the government’s investigation. “But unfortunately we’ve missed it.” 

In the absence of definitive proof, skeptical scientists say it’s essential to keep looking for answers. Failing to do so could have fatal repercussions—not just for elephants, but for all animal wildlife in and around the region.  “If they had more knowledge and more awareness, they might be able to prevent it not only in elephants, but in other valued wildlife and in domestic animals and human exposures as well,” Beasley says.