Wildlife officials in Botswana say the recent deaths of hundreds of elephants in the Okavango Delta panhandle was caused not by humans, but by waterborne bacteria.
More than 330 elephants died in the panhandle between April and June, and wildlife officials did not know the cause. The carcasses were found with their tusks intact, eliminating the possibility of poachers.
Dr. Mmadi Reuben, the chief veterinary officer for Botswana’s Department of Wildlife and National Parks, told a news conference Monday that the cause was cyanobacteria, a waterborne bacteria that produces deadly toxins which can affect an elephant’s nervous system.
He said officials are still investigating why the bacteria affected only elephants.
“We know the elephant to be the only animal for example, that is drinking below the surface of the water. And where the depth is a challenge, it clearly shows the possibility of the specie being able to suck the silt, which is really where the growth of the cyanobacteria is,” he said.
Department of Wildlife and National Parks deputy director Cyril Taolo said cyanobacteria develops when environmental changes occur.
The vast Okavango Delta experienced a dry period until recently, when water levels began rising.
“This is not a phenomenon that was just seen now. It is something that happens quite a lot when there are these environmental changes. At this stage certainly, we cannot talk about human involvement,” he said.
Poachers have decimated elephant populations in other parts of Africa, but in Botswana, the animals continue to thrive. The country has the world’s largest elephant herd, estimated at more than 130,000.