According to protection director Niall McCann at the UK charity National Park Rescue, some carcasses appear to be clustered around the water holes, while others “fell perpendicular to their faces”.
Observers said that the live elephants seen nearby seemed physically weak and someone was walking around, unable to change direction. Other species in the region have not been shown to be affected by things that hit elephants.
The Botswana government is testing samples of dead elephants, but has not yet identified a cause of death.
McCann said an unusual number of elephant carcasses were first recorded at the beginning of May.
“Horrible – we must know what happened in hell,” he added, adding that he could not remember another time when many elephants died for a mysterious reason.
“800 of them lie as a magnet for criminals,” he added.
McCann said there are a number of possibilities for what causes deaths, including elephant-specific parasites – even Covid-19.
“What I want to emphasize is that this has the potential to be a public health crisis,” he said.
Whatever the reason, McCann said it was important to get under it, as the loss of elephant life is “globally important”.