Researchers were baffled when elephants began dropping like flies in the African nation of Botswana earlier this year. Now, government researchers say they've figured out what happened, and it doesn't involve poachers. Instead, they say a naturally occurring bacteria in watering holes is the culprit, reports the BBC. "Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths," says a wildlife official. "These are bacteria found in water." In all, an estimated 330 elephants were found dead in the nation in May and June. Another official, the deputy director of Botswana's wildlife ministry, says "there is absolutely no reason to believe that there was human involvement in these mortalities." That had been a theory because of growing anti-elephant sentiment in the nation, particularly from farmers worried about cropland, notes the Washington Post.
The announcement, however, doesn't answer all questions. One big one: Why weren't there mass die-offs of other animals at the watering holes? Government authorities say they're investigating several hypotheses about that. One leading theory is that elephants are particularly vulnerable because they drink so much water and spend so much time in the watering holes, reports the Guardian. "I hope that what the government has said is true because it rules out some of the more sinister things,” says Niall McCann of the UK's National Park Rescue. The BBC notes that one modern villain may have played a role, however: climate change. These types of toxic blooms may become more common in warmer temperatures. (Read more elephants stories.)