Polar bears act as crucial providers for Arctic species

(Press-News.org) Photos: here

SAN DIEGO (Oct. 28, 2025) – A new study published in the scientific journal Oikos reveals for the first time the critical role polar bears play as carrion providers for Arctic species. Researchers from University of Manitoba and San Diego Zoo Wildlife Alliance, alongside researchers from Environment and Climate Change Canada, and the University of Alberta, have estimated that polar bears leave behind approximately 7.6 million kilograms of their prey annually, creating a massive and vital food source for a wide network of arctic scavenger species. 

This research demonstrates that these apex predators are a crucial link between the marine and terrestrial ecosystems. By hunting seals on the sea ice and abandoning the remains, polar bears transfer a substantial amount of energy from the ocean to the ice surface, making it accessible to other animals. The study identifies at least 11 vertebrate species known to benefit from this carrion, including Arctic foxes and ravens, with an additional eight potential scavenger species. 

“Our findings quantify for the first time, the sheer scale of polar bears as a food provider to other species and the interconnectedness of their ecosystem,” says Holly Gamblin, lead author of the study and PhD Candidate in the Department of Biological Sciences at the University of Manitoba. “What is apparent from this review is that there is no other species that adequately replaces how a polar bear hunts, in which they drag their prey from the water to the sea ice and leave substantial remains for other species to access.” 

Past research has emphasized that continued warming in the Arctic and the resulting loss of sea ice directly endanger polar bear populations. However, this new research highlights that a decline in polar bears would not only impact the species itself but the loss of the carrion they provide could have significant consequences for the entire Arctic ecosystem. 

“Our research highlights the important role of polar bears as carrion providers,” says Dr. Nicholas Pilfold, Scientist in Population Sustainability at San Diego Zoo Wildlife Alliance. “The sea ice acts as a platform for many species to access scavenging resources provided by polar bears, and ultimately, declines in sea ice will reduce access to this energy source. Our findings indicate that documented declines in polar bear abundance in two subpopulations have already resulted in the loss of more than 300 tonnes of food resources for scavengers annually.” 

These findings highlight the interdependence of arctic wildlife species and their shared vulnerabilities in the face of rapid environmental change. With polar bear populations continuing to decline, this research underscores the urgency of conservation efforts to protect them, not only for their own sake but for the species that rely on them. 

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About San Diego Zoo Wildlife Alliance  
San Diego Zoo Wildlife Alliance, a nonprofit conservation leader, inspires passion for nature and collaboration for a healthier world. The Alliance supports innovative conservation science through global partnerships and groundbreaking efforts at the world-famous San Diego Zoo and San Diego Zoo Safari Park, both leading zoological institutions and accredited botanical gardens. Through wildlife care expertise, cutting-edge science and continued collaboration, more than 44 endangered species have been reintroduced to native habitats. The Alliance reaches over 1 billion people annually through its two conservation parks and media channels in 170 countries, including San Diego Zoo Wildlife Explorers television, available in children’s hospitals across 14 countries. Wildlife Allies—members, donors and guests—make success possible.  

About University of Manitoba 
The University of Manitoba (UM) is recognized as Western Canada's first university. It is part of the U15, ranking among Canada’s top research-intensive universities and provides exceptional undergraduate and graduate liberal arts, science and professional programs of study.  

UM campuses and research spaces are located on original lands of Anishinaabeg, Ininiwak, Anisininewuk, Dakota Oyate, Dene and Inuit, and on the National Homeland of the Red River Métis. UM recognizes that the Treaties signed on these lands are a lifelong, enduring relationship, and we are dedicated to upholding their spirit and intent. We acknowledge the harms and mistakes of the past and the present. With this understanding, we commit to supporting Indigenous excellence through active Reconciliation, meaningful change, and the creation of an environment where everyone can thrive. Our collaboration with Indigenous communities is grounded in respect and reciprocity and this guides how we move forward as an institution. For more information, please visit umanitoba.ca.    

 

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B-roll and photos of polar bears  END