During aerial reconnaissance over Botswana’s Okavango Delta, which is renowned for its expansive grasslands and abundant wildlife habitat, on May 25, 2020, conservationists witnessed a shocking and heart-breaking sight: one hundred and sixty-nine dead elephants. They discovered more carcasses on a follow-up mission a few weeks later in June, bringing the total to three hundred and fifty.
However, three years after the conservation disaster that killed over 350 elephants in Botswana, with an additional 35 elephants suffering a similar fate in Zimbabwe two months later, a new study report claims that the cause of the deaths was a bacterium known as Pasteurella bisgaard taxon 45.
“The sudden mortality of African elephants (Loxodonta africana) in Botswana and Zimbabwe in 2020 provoked considerable public interest and speculation. Poaching and malicious poisoning were excluded early on in the investigation. Other potential causes included environmental intoxication, infectious diseases, and increased habitat stress due to ongoing drought. Here we show evidence of the mortalities in Zimbabwe as fatal septicaemia associated with Bisgaard taxon 45, an unnamed close relative of Pasteurella multocida,” states the report.
The tests conducted by the scientists show that blood poisoning caused the elephants’ deaths. The bacteria is also linked to over 200,000 saiga antelope deaths that occurred in central Kazakhstan within three weeks in 2015.
“Bacterial 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,” states the report titled “Pasteurella sp. associated with fatal septicaemia in six African elephants”.
Additionally, the report subtly alerts conservationists to the dangers of this deadly infection. “Our results demonstrate that Bisgaard taxon 45 is associated with a generalised, lethal infection and that African elephants are susceptible to opportunistically pathogenic Pasteurella species. This represents an important conservation concern for elephants in the largest remaining meta-population of this endangered species,” states part of the report which was undertaken by scientists from the United Kingdom, Zimbabwe and South Africa.
The report mentions, among other things, that Bisgaard taxon 45 had not been discovered in African elephants before. “The epidemiology of Bisgaard taxon 45 is currently unknown, and septicaemia such as that seen with P.multocida has not been previously reported with this organism”.
A few months ago, the Kavango Zambezi Transfrontier Conservation Area (KAZA) survey noted that Botswana hosts the world’s largest elephant population. The results of the survey also noted that the estimated elephant population for the entire KAZA region is 227,900. The findings also indicate that, with 131 909, Botswana is home to the world’s greatest elephant population. Estimated elephant populations for Zimbabwe are 65, 028, Namibia 21, 090, Angola 5,983 and Zambia 3, 840.
“Across the KAZA TFCA, 58% of the elephants were found to be in Botswana, 29% in Zimbabwe, 9% in Namibia, and the remaining 4% were found in Zambia and Angola combined,” states the report.