Researchers from the University of Helsinki have uncovered where polar bears found refuge during the most recent long warming event that began about 15,000 years ago. Their shelter locations included northern Siberia and islands off the Canadian Arctic coast, with findings published in the journal Quaternary Science Reviews (QSR).
As the last ice age waned, vast melting reduced the ice sheets over Scandinavia and North America, helping to stabilize global temperatures in its wake.
Fossil analysis indicates that polar bears inhabited the southwestern fringe of the Scandinavian ice sheet during the cold spell. As ice withdrew, these apex predators migrated toward the East Siberian Sea coast in Siberia, northern Greenland, and the Canadian archipelago’s island groups.
Experts note that polar bears seek the coldest and most stable environments available. In the warmest interval, roughly from 9,000 to 5,000 years ago, regional temperatures were about 1.5–2.5 °C higher than today, a shift that stressed sea ice and limited hunting habitat for seals, their primary prey.
The current studies imply that climate change now poses a renewed risk to polar bears as Arctic sea ice retreats with human-driven warming. Projections suggest a shrinking summer ice cap could intensify habitat loss, underscoring the need for proactive management and conservation measures in coming years.
Biologists have long examined ancient mammals, including the woolly mammoths, to understand how wildlife adapted to shifting climates and changing landscapes. This recent work adds a chapter to that broader narrative by tracing how habitat corridors and refugia shaped polar bear distribution during a past warming period.