Scientists Discover the Cause Behind African Elephants' Mysterious Deaths
Scientists have discovered the cause behind the mysterious mass deaths of African elephants The outbreaks are more likely to occur due to the climate crisis
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Scientists have now unraveled the mystery behind the mysterious mass deaths of African elephants. According to a new report authored by these scientists, the outbreaks could be more prone to occur due to the conditions caused by the ongoing climate crisis.
Between late August and November 2020, a perplexing incident occurred in northwestern Zimbabwe where a total of 35 African elephants tragically lost their lives. What adds to the mystery is that within a 24-hour period, eleven of these majestic creatures met their demise.
"The timing of their death is truly puzzling. It's remarkable how many elephants died within such a short time frame, not in immediate proximity to one another. This is truly unprecedented, particularly within this region," commented Dr. Chris Foggin, a veterinarian at Victoria Falls Wildlife Trust in Zimbabwe. Dr. Foggin is also a coauthor of the study investigating the cause behind these tragic deaths.
350 elephants in the northern region of Botswana also died abruptly in a span of three months earlier that year. The sudden die-offs among Africa's largest elephant population initially baffled officials and experts, who attributed them to poaching, poisoning, and drought.
The research, based on samples taken from 15 elephants that died in Zimbabwe, revealed that it was indeed a bacterial infection that led to their demise. Published on October 25 in the journal Nature Communications, the analysis indicated that the elephants were infected with a relatively unfamiliar bacterium known as Bisgaard taxon 45, which resulted in septicemia or blood poisoning.
The deaths took place as food and water resources dwindled during the dry season, forcing the elephants to travel increasing distances to look for water and to forage.
Researchers took samples from 15 of the dead elephants.
Chris Foggin
The outbreak was likely influenced by heat, drought, and population density in the area, as stated by the authors. Furthermore, as Earth continues to warm, the predicted increase in extreme conditions may result in a higher number of elephant deaths.
It is too early to conclude that climate change has affected this situation, but it could potentially do so in the future if droughts become more frequent and prolonged, or if rainfall patterns change and the dry season becomes harsher, according to Foggin. If that happens, Foggin believes that similar incidents of mortality are more likely to occur again.
The study mentioned that the elephant deaths in Botswana have been linked to cyanobacterial neurotoxins, but additional information has not been made public. Foggin stated that there is no proven link between the elephant deaths in Zimbabwe and Botswana.
The African elephant is a critically endangered species due to poaching and the destruction of its natural habitat. The International Union for Conservation of Nature Red List classifies it as an endangered species. Between 2007 and 2014, the population decreased by 144,000 individuals, leaving approximately 350,000 remaining. The study also estimates that the population continues to decline at a rate of 8% annually.
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227,900 elephants inhabit the Kavango-Zambezi Transfrontier Conservation Area, spanning 500,000 square kilometers (193,051 square miles) of protected land, primarily located in Botswana and Zimbabwe.
According to the study authors, infection was detected in six out of the 15 samples. This finding was confirmed through laboratory isolation of the bacterium and comprehensive genetic analysis.
There was no evidence of toxins, including those from cyanobacteria, or any viral infection.Â
Delays resulted in poor sample quality
Furthermore, the study remarked that there were no reports or observations of deceased scavengers or other wildlife species in the vicinity of the dead elephants, which is what would typically occur in cases of cyanide or other deliberate poisoning.
The study also pointed out that while there wasn't any confirmed evidence of Bisgaard taxon 45 in more than six deaths in Zimbabwe, the elephants that were examined were in satisfactory physical condition, making it unlikely that their deaths were solely due to drought-induced starvation or severe dehydration.
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None of the elephants were found with their tusks removed due to poaching, and there were no apparent signs of injury. Additionally, tests conducted for anthrax yielded negative results, as stated by Foggin.
The researchers acknowledged their inability to detect the bacteria in the remaining samples, which they attributed to subpar sample quality and delays in obtaining the necessary permits. Consequently, they were unable to conduct certain laboratory procedures due to the time constraint.
The study stated, "The majority of carcasses had already degraded when sampled, leading to inadequate initial sample quality. Furthermore, the process of exporting wildlife samples for analysis requires acquiring permits from various entities, which often takes several months."
What information is available regarding the bacterium?
In the past, Bisgaard taxon 45 has been linked to bite wounds from tigers and lions in humans. Additionally, the bacteria have been detected in both a chipmunk and captive parrots that were in good health.
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The unidentified microorganism is closely linked to a prevalent bacterium called Pasteurella multocida. This bacterium is responsible for causing hemorrhagic septicemia in various animals, such as Asian elephants.
The study mentioned that the same bacterium was also associated with the widespread fatalities of 200,000 saiga antelope, a critically endangered species, in Kazakhstan in 2015. Foggin stated that researchers had been observing wildlife in the region to detect the presence of the bacteria, and no additional cases of elephant deaths caused by Bisgaard taxon 45 had been verified after 2020.
