Here’s How Climate Change Has Caused Polar Bears to Get Huge ‘Ice Balls’ on Their Paws

In recent years, researchers have been observing weird clumps of ice on the paws of polar bears which isn't a commonly occurring phenomenon among these Arctic animals. The changing climatic conditions in Greenland have caused native animals like polar bears to sustain concerning wounds on their paws, according to a new study published in the journal Ecology in October 2024. The experts noted that two polar bears brought in primarily for population assessment had crippling, dinner-plate-sized ice balls sticking to their feet. 

The ice balls were far from being harmless as the researchers discovered that the polar bears had deep, bleeding cuts beneath the ice stuck between their paw pads. The experts were baffled by the observation and theorized that the warming climates could be a possible cause of the injuries. “I'd never seen that before. The two most affected bears couldn't run — they couldn't even walk very easily,” Kristin Laidre said in a statement. She is the lead author of the study and associate professor at the University of Washington. She further revealed that the ice chunks were stuck in the carnivore’s hair and skin. 

The lead author added, "The chunks of ice weren't just caught up in the hair. They were sealed to the skin, and when you palpated the feet it was apparent that the bears were in pain." According to the study, the formation of the ice balls sticking to the paws is due to the slushy snow, caused by warming climates in the region, sticking between the bumps on the pads of the polar bears. The bumps create friction to provide them the grip to walk on slippery surfaces. The slushy snow then freezes into a solid, thus, forming ice blocks of about 12 inches. Meanwhile, the bleeding cuts under their paws were due to the wet snow and freeze-thaw cycles that resulted in the formation of brittle ice. It was also reported that the Artic regions witnessed more rainfall than usual now.

Assistant professor of biology at Old Dominion University in Virginia, John Whiteman told LiveScience, “This report is definitely surprising. If the conditions that encourage ice clumps become a common occurrence across a large area, more bears would be at risk for foot damage." He attested to the researchers of the study’s claim stating that these paw injuries were unheard of previously. Whiteman also serves as the chief research scientist at the non-profit organization Polar Bears International. 

The primary study found that about one in four polar bears observed from two populations in East Greenland and Kane Basin from 2012 to 2022 had ice-related injuries. Lead author Laidre was assisted by co-author and wildlife biologist and veterinarian, Stephen Atkinson. The injured polar bears were mostly adult males and traveled longer distances than females in addition to weighing more. 31 out of 61 bears showed skin ulceration, laceration, hair loss, or ice balls on their paws in the Kane Basin population. These issues were prevalent in 73% of adult males as observed between 2013 to 2013, per the study. 

Whereas, 15 out of 124 polar bears were affected in the East Greenland population between 2018 and 2022. In their bid to explain the occurrence, the researchers also talked to indigenous hunters in the regions. They speculated that the paw lesions were due to increased movement during the hunting and mating seasons but also attributed it as a new phenomenon.