in the Okavango Delta Researchers have uncovered the reason behind the sudden death of many endangered elephants in the Okavango Delta.
In the months of May and June 2020, the passing of 350 elephants in Botswana’s Okavango delta perplexed conservationists and led to worldwide conjecture about the reason behind it. Elephants of various ages and genders were impacted, exhibiting symptoms such as walking in circles before experiencing sudden death and falling onto their faces. In a separate incident two months later, an additional 35 elephants passed away in north-western Zimbabwe.
According to government officials, the deaths in Botswana were linked to a cyanobacterial toxin, but no specific information was released at that time.
The tests conducted on the deceased elephants in Zimbabwe have yielded results indicating that the cause of death was a relatively unknown bacterium called Pasteurella Bisgaard taxon 45. This bacterium caused septicaemia, also known as blood poisoning.
According to a study published in the journal Nature Communications, the bacteria causing the infection has not been connected to previous cases of elephant deaths. The researchers suggest that it may be the same bacteria responsible for deaths in nearby countries.
According to the paper, this poses a significant conservation issue for elephants in the largest remaining meta-population of this endangered species. The paper was authored by a global team of researchers from the Victoria Falls Wildlife Trust, the University of Surrey, laboratories in South Africa, and the UK government’s Animal and Plant Health Agency (APHA).
The population of African savanna elephants is decreasing at a rate of 8% annually, largely due to poaching, leaving only 350,000 in their natural habitat. The research suggests that infectious illnesses should also be considered a contributing factor to their decline.
According to Dr. Arnoud van Vliet of the University of Surrey, the infection presents another risk to elephant conservation in addition to other disease-related threats. Elephants are known for their social nature and the drought conditions at the time likely contributed to their stress and increased the likelihood of an outbreak.
Researchers have connected Pasteurella bacteria to the unexpected demise of approximately 200,000 saiga antelopes in Kazakhstan. This event may provide insight into the fate of the elephant herds. It is believed that the Pasteurella bacteria typically resides without harm in the tonsils of some or all of the antelopes. However, a spike in temperature to 37C resulted in the bacteria entering the bloodstream and causing septicaemia.
According to the paper, the Bisgaard taxon 45 has been discovered in tigers, lions, chipmunks, and psittacines through testing a bite wound in a human.
Experts also examined the presence of cyanide, a substance that has been used to harm elephants, but no poisons were found in the carcasses or surrounding water sources. Another possible explanation was the consumption of toxins from blooms of algae. Poaching was quickly dismissed as a cause since the tusks were still intact on the carcasses.
Dr. Chris Foggin, a wildlife veterinarian at the Victoria Falls Wildlife Trust and the lead investigator, stated that investigating the large number of animal deaths was a difficult task.
One issue that we frequently encounter is identifying and accessing carcasses in a timely manner to collect meaningful samples. In addition, we were unaware of the specific illness that we may be dealing with,” he stated.
At first, we thought it might be anthrax, a disease common in the region. It could also be another illness that could harm people. As a result, we had to be careful when performing autopsies on the elephants, which is a challenging task due to their size. This was especially challenging since we were working in outdoor conditions.
The researchers were not able to go to the location in the nearby country of Botswana, and the majority of the approved samples were taken from decaying animals. According to the article, the discovery of blood poisoning “could possibly be an ongoing event in this area,” as past occurrences were not detected due to inadequate testing.