Scientists identify avian cholera as major cause of penguin deaths in Antarctica

An international research team, comprising wildlife veterinarians and biologists, has uncovered that avian cholera, a disease caused by the bacterium Pasteurella multocida, was the primary cause of thousands of Adélie penguin deaths in Antarctica's remote Danger Islands in March 2024. This finding contrasts with the initial suspicion that high pathogenicity avian influenza (H5N1) was responsible for the mass mortality event.

In the study published in Proceedings of the Royal Society B: Biological Sciences, researchers found that avian cholera was present in 46 out of 49 sampled penguin carcasses, while H5N1 was only detected in a few. The bacterium has been identified in these penguins before, with genetic analysis revealing that the current strain is closely related to one identified in Antarctic seabirds over two decades ago.

The discovery of avian cholera as a major cause of penguin deaths in Antarctica highlights the need for comprehensive disease investigations and regular wildlife health surveillance, as it suggests this pathogen may be more widespread and underestimated than previously recognized. The study's findings underscore the importance of continued monitoring of Antarctic wildlife, particularly as the threat of H5N1 continues to raise concerns for seabird and marine mammal populations.