BRONX, NY, August 12, 2026—A polar bear spends nearly a day walking across a remote Arctic island, crushing and consuming eggs, and destroying almost an entire colony of seabird nests. While reported elsewhere in the Arctic, until recently, such scenes were almost unheard of in Alaska. Today, according to a new study co-led by the Wildlife Conservation Society (WCS) and Cooper Island Arctic Research and published in the journal Polar Research, they are becoming a visible sign of how climate change is destabilizing one of Earth's fastest-warming ecosystems.

As disappearing summer sea ice leaves polar bears with less access to the seals they have relied on for millennia, more bears are spending time on land and turning to seabird colonies for food. Drawing on one of the longest continuous records of Arctic seabird monitoring ever assembled on Cooper Island, WCS scientists and collaborators documented a dramatic increase in polar bear predation on black guillemots and common eiders along Alaska’s Arctic coast.

In July 2024, researchers documented one of the clearest examples of that shift when a single polar bear destroyed 89 percent of the nests in a common eider colony on Spy Island in less than one day—the first predation event of this scale at a seabird colony in Alaska. At nearby Cooper Island, where seabirds have been monitored since 1975, polar bear predation rose sharply after the record sea-ice retreat of 2007. Bears eventually even learned to defeat specially designed nest boxes created to protect the birds.

"For decades these barrier islands served as places where seabirds could nest with relatively little pressure from large land predators," said Kayla Shively, Conservation Ecologist with WCS's Arctic Beringia Program and lead author of the study. "What we're seeing now is that as polar bears spend more time on shore, those relationships are changing. It's another reminder that climate change isn't affecting one species at a time—it is reshaping the connections between species across the Arctic."

The researchers also found that bears are arriving earlier in the nesting season, increasing losses of eggs, chicks, and breeding adults that are vulnerable due to congregating in relatively large numbers on small islands. At Cooper Island, polar bear predation caused complete reproductive failure in the black guillemot colony during both 2024 and 2025.

Black guillemots have already declined as warming seas reduced the availability of Arctic cod, their primary prey. Common eiders face growing pressure from flooding and shoreline erosion. Polar bear predation is now one more threat.

"When a top predator like the polar bear changes how and where it hunts, it's telling us something fundamental about the ecosystem," said Dr. Martin Robards, Regional Director of WCS's Arctic Beringia Program and a co-author of the study. "These aren't isolated events. They're visible signs that one of the world's most intact ecosystems is being destabalized by the loss of sea ice, with consequences that ripple through wildlife communities in ways we're only beginning to understand."

The study highlights why long-term field research matters. Without decades of observations by Dr. George Divoky at Cooper Island and continued monitoring of Alaska's barrier islands by WCS teams, these changes might have appeared to be isolated incidents rather than evidence of a profound ecological shift.

As the Arctic continues to warm, scientists expect these new interactions between predators and prey to become more common. The changes documented in this study, and by others elsewhere in the Arctic, are not simply altering the fate of individual bird colonies in a few specific locations. They reveal a more systemic “New Arctic” that is being reshaped as species adapt to a world with less ice—a reminder that the effects of climate change are measured in the changing relationships that hold entire ecosystems together.

But even at this stage of the climate crisis, meaningful action can still strengthen the resilience of Arctic species, their capacity to adapt, and if the climate stabilizes over coming generations, even recover. Meeting emissions-reduction targets, protecting intact habitats, and sustaining long-term, ecosystem-focused research will be essential to helping understand the changing needs of species as they adapt, and for guiding their conservation in this New Arctic. 

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