Authorities have reported that hundreds of elephants that died under mysterious circumstances in Botswana probably died due to natural toxins. Authorities have so far ruled out anthrax and poaching as the reason for their deaths as the tusks were found intact. The government has confirmed the death of 281 elephants, although independent conservationists say more than 350. Conservationists doubted elephants had been dying in the area for about three months, and mortality was not limited to age or gender. Preliminary tests conducted in various countries have not been fully convincing and more are being carried out at specialist labs in South Africa, Canada, Zimbabwe, and the US.