Mysterious elephant deaths in Zimbabwe in 2020 have been linked to blood poisoning caused by bacteria, according to a study in Nature Communications. The deaths of 35 elephants in north-western Zimbabwe and 356 others in Botswana raised concerns in the scientific community, prompting an investigation into the cause. The study found that the deaths were possibly due to septicaemia caused by Bisgaard taxon 45, a bacterium closely related to Pasteurella multocida.
The African forest and savanna elephants are both endangered species, with their populations declining significantly over the past few decades. The deaths of these elephants in Zimbabwe and Botswana added to the growing list of threats to elephant conservation, including tuberculosis, anthrax, and elephant endotheliotropic herpesvirus.
Scientists also considered other possible causes such as environmental intoxication, infectious diseases, and increased habitat stress due to drought. However, their analysis failed to show evidence of cyanide poisoning, which is sometimes used to kill elephants. The drought and lack of sufficient nutrition were not the direct causes of death, but they may have compromised the elephants’ immunity and overall health.
The source of infection and transmission route of the bacterium are still unknown, and the researchers suggested that intraspecific transmission via inhalation or ingestion is possible due to the sociability of elephants. The study also mentioned the rapid multiplication of bacteria in carcasses and the natural curiosity of elephants about their dead, which could increase the risk of exposure.
The findings of the study highlight the urgent need for continued conservation efforts to protect the remaining elephant populations. The deaths of these endangered animals serve as a reminder of the various threats they face and the importance of understanding and addressing these challenges to ensure their survival.