A cooperative team of zoologists from the United States and Canada examined how an extended summer ice melt affects polar bears in the Arctic. The researchers concluded that these apex predators will struggle to adapt to prolonged warm seasons and may be at increasing risk of extinction. The findings appeared in Nature Communications, a respected scientific journal.
In the study, twenty polar bears were observed over three consecutive weeks of summer. The bears adopted several energy-saving tactics as the ice receded, with most losing weight rapidly, roughly about one kilogram each day. This rapid weight loss underscores how quickly energy reserves can dwindle when hunting opportunities vanish and fat stores are drawn down to sustain basic metabolism.
Adult male polar bears can reach up to three meters in length and weigh more than seven hundred kilograms. Their heft is supported by a diet rich in energy-dense seals, which are most efficiently captured on stable sea ice. When ice is scarce, the bears must rely on alternatives and endure a tougher energy balance as the hunt shifts from platform to absence of platform.
With ice breaks occurring earlier in the year, many bears chose to rest as a means of conserving calories. Others scavenged for food, feeding on carrion, berries, algae, and various aquatic plants. Some individuals spent close to forty percent of their waking hours searching for food, highlighting the strain of a changing habitat on daily routines and energy budgets.
There were notable long-distance attempts by three polar bears that swam extensively. One bear crossed a bay, traveling roughly 175 kilometers, illustrating the endurance these animals can display even when prey becomes harder to find. While some carcasses of beluga whales and seals were located in the water by investigators, a single bear could not feed on these discoveries or haul any catch to shore, emphasizing the difficulty of securing nourishment in a warming, ice-short Arctic.
The study co-author Charles Robbins, who directs a prominent wildlife research center, stated that polar bears cannot survive on land for extended periods. Foraging bears still lost weight at the same rate as those resting on shore, underscoring the instability of a land-based strategy under longer warm seasons.
Experts warn that hunger among polar bears is likely to intensify as the ice-free window widens with ongoing climate warming. The research adds to a growing body of evidence from North American scientists about how climate change is reshaping the life of top Arctic predators and the broader ecosystem in which they function.
Historical observations indicate that polar bears have shown sensitivity to climate fluctuations for thousands of years, with earlier shifts linked to past climate cycles. The present trajectory, however, points to a pace and scale of change that challenges the bears’ ability to adapt quickly enough to survive.