Scientists have discovered the cause of mass deaths of African elephants in Zimbabwe and Botswana in 2020. A bacterial infection called Bisgaard taxon 45 caused septicemia, or blood poisoning, in the elephants. The outbreak was likely triggered by heat, drought and population density, which forced the elephants to travel long distances for food and water.
The study, published in the journal Science Communications, is the first to identify the bacterium as a lethal pathogen in elephants. The researchers collected samples from 330 elephant carcasses in the two countries, and found that 70% of them had high levels of the bacteria in their blood.
The bacteria are normally found in the respiratory tract of elephants, but can enter the bloodstream through wounds or stress. The elephants showed signs of neurological impairment, such as walking in circles, before collapsing and dying.
“This is the first time that this bacterium has been shown to cause deaths in elephants. It’s a bit of a surprise that it’s causing such a serious disease,” said Dr. Niall McCann, co-author of the study and director of conservation at UK-based charity National Park Rescue.
The authors of the study warned that the climate crisis could make such events more frequent in the future, as rising temperatures and changing rainfall patterns affect the availability of water and food for the elephants.
“The die-off appeared to be associated with a drought, which means that we may see more of these events in the future as climate change takes hold and exacerbates the situation,” said Dr. Chris Thouless, head of research at Save the Elephants, a Kenya-based conservation group.
The researchers also urged for more proactive and regular health monitoring of the endangered species, which is facing a multitude of threats, including poaching, habitat loss and human-wildlife conflict.
“It is deeply concerning that this outbreak was only discovered as a result of the scale of the mortality event. It highlights the need for more research and surveillance of elephant health,” said Dr. McCann.
Dr. Cyril Taolo, co-author of the study and acting director of the Department of Wildlife and National Parks in Botswana, said the findings were crucial for the conservation of the elephants, which are vital for the health of the ecosystems and the livelihoods of the people.
“This is a wake-up call to the world that we need to be doing more to protect these magnificent animals, which are so important for the health of our planet,” he said.
– Mystery of African elephants dropping dead unraveled by scientists, CNN, November 6, 2023
– Scientists identify cause of mass African elephant death – but warn threat remains, ITV National News, November 7, 2023
– Scientists Unravel Mystery of African Elephant Die-Offs: Threat Persists Amid Climate Crisis, Bollyinside, November 6, 2023
– Scientists solved the mystery of African elephant die-offs. The threat may not be over, MSN, November 6, 2023