Mystery sudden deaths of endangered African elephants now solved, scientists say

A team of scientists say they have discovered what caused the sudden deaths of hundreds of elephants in Africa in 2020.

More than 300 elephants died in Botswana’s Okavango delta in the May and June of 2020, with another 35 dying in Zimbabwe two months later.

The deaths triggered an international mystery, with only poaching and anthrax poisoning initially ruled out.

Initially, officials put the deaths down to toxins that were produced by tiny organisms in water and soil and ingested by the mammals, which was put down to climate change.

However, scientists say tests on the animals reveal they died from a bacteria called Bisgaard taxon 45 – an unnamed relative of Pasteurella multocida, which causes a number of different illnesses in animals.

In the elephants tested, it manifested as septicaemia, or blood poisoning.

Elephant populations have decreased by 144,000 from 2007 to 350,000, with a decline of 8% a year, scientists estimate.

Scientists in the Nature Communications journal said Pasteurella multocida had not previously been linked to deaths in elephants, but that it could now “represent an ongoing phenomenon in this region”.

The paper added: “Septicaemia adds to a growing list of disease-related threats to elephant conservation, including tuberculosis, anthrax, elephant endotheliotropic herpesvirus, encephalomyocarditis virus, floppy trunk syndrome, and malicious poisoning.”

Pasteurella bacteria was previously found in a herd of 200,000 saiga antelopes that died suddenly in Kazakhstan, with scientists hoping that case could help shed a light on what happened in Africa.

The peer-reviewed research was undertaken by an international team, which included scientists from the UK’s Animal and Plant Health Agency, the Victoria Falls Wildlife Trust and laboratories in South Africa.