Climate change has broad ecological implications for wildlife, especially for species that rely on temperature-sensitive habitats. For polar bears (Ursus maritimus), loss of Arctic sea ice reduces access to prey and lengthens seasonal fasting periods leading to behavioral, nutritional, and reproductive impacts that may result in population declines. Secondary factors, such as disease and contaminants can exacerbate primary stressors and new health-related conditions are likely to emerge.  For example, once unusual but now increasingly frequent warming cycles are creating unprecedented icing conditions that have demographic consequences for cold-adapted mammals.

We report on icing-related lesions observed in wild polar bears during live-capture research in two high-latitude subpopulations, Kane Basin (KB) and East Greenland (EG), between 2012 and 2022.  We observed ice build-up, hair loss (alopecia), and skin ulcerations primarily affecting the feet of adult bears as well as other parts of the body. The most severely affected individuals had blocks of ice up to 30 cm in diameter adhered to the foot pads, deep, bleeding ulcerations of foot pads and exhibited lameness. These injuries have not been observed during previous research in these areas or reported in the scientific literature, suggesting this may be a new phenomenon. To provide context for our observations, we conducted interviews with Indigenous polar bear subsistence hunters in West and East Greenland and Nunavut to document Indigenous knowledge about the potential causes and frequency of these injuries.

This video was collected by mobile phone in East Greenland. The polar bear in the video is temporarialy sedated for physical capture. The video has not been processed.