New research led by the University of Otago—Ōtākou Whakaihu Waka suggests that some bird species may be using natural geothermal areas as a way to remove parasites and pathogens. Published in the journal Ornithology, the study found that certain birds appear to seek out and preen in the sulfurous steam of geothermal regions. Senior author Crid Fraser, from the Department of Marine Science, explained that this behavior might help birds eliminate harmful microorganisms, especially in a world where birds are known to carry disease agents across the globe. Fraser first noticed penguins and seabirds basking in volcanic steam in Antarctica, a behavior that seemed odd for cold-adapted species. This observation led to the idea that the birds might be using the sulfurous steam for health reasons. Sulfur is a powerful insecticide and fungicide commonly used in agriculture, and its presence in geothermal steam could have similar effects. To test this, two undergraduate students spent their summer break observing five bird species in geothermal and non-geothermal areas around Rotorua. Over several weeks, they recorded behavioral data from 334 bird observations, totaling about 3,000 minutes. The study found that some birds, including black swans and gulls, spent significantly more time preening in geothermal areas. Lead author and student Rani Cousens suggested that by ruffling their feathers, the birds may be allowing sulfur-rich gases to reach their plumage, which could help remove parasites. Fraser emphasized that the results are preliminary and more research is needed to confirm the findings. However, he noted that the study provides exciting evidence that birds might be using geothermal areas for grooming purposes. Fraser also pointed out that while geothermal areas have long been considered beneficial for human health, such as in spa treatments, there is limited evidence supporting these benefits for wildlife. The research was conducted in collaboration with local ecologists from Te Arawa, the Department of Conservation, and Wildlands, ensuring that the study included traditional knowledge and conservation perspectives.