Bacterial infection caused African elephant mass deaths, with climate change potential future factor.
A new report has revealed the cause of mysterious mass deaths among African elephants, suggesting a potential link to climate change. Between August and November 2020, 35 African elephants in northwestern Zimbabwe died under baffling circumstances, with 11 perishing in just 24 hours. Initial theories attributed the die-offs to poaching, poisoning, and drought. However, a recent study based on samples from 15 of the deceased animals found that a little-known bacterium called Bisgaard taxon 45 caused septicemia, or blood poisoning.
The deaths occurred during a dry season when food and water resources were scarce, forcing the elephants to travel long distances in search of sustenance. The study points to heat, drought, and population density as likely contributing factors to the outbreak. Scientists warn that if extreme conditions linked to climate change become more frequent, similar elephant deaths may occur in the future.
Notably, about 350 elephants in neighboring northern Botswana also experienced sudden deaths during the same year, but the reasons behind these fatalities were different, attributed to cyanobacterial neurotoxins. No proven connection has been established between the Zimbabwe and Botswana elephant deaths. African elephants face severe threats from poaching and habitat loss, with their population decreasing from 2007 to 2014, and ongoing losses estimated at 8% annually.
The research detected evidence of Bisgaard taxon 45 infection in six of the 15 samples, supported by lab testing and genetic analysis. There was no sign of toxins, viral infections, external trauma, or poaching in the affected elephants. Researchers encountered challenges in obtaining permits and maintaining sample quality, which hindered further analysis. While the bacteria were not confirmed in additional mortalities since 2020, scientists continue to monitor the situation to better understand and potentially prevent future outbreaks.
