A polar bear at a zoo walks around with a purple spot on its fur and a Burr on Fur tracking device

Photo: C. Breiter / Assiniboine Park Zoo

Purple Fur on Polar Bears: Coalition of Zoos Advancing Polar Bear Research



26 Jan 2022

A new Masterplan by the Polar Bear Research Council provides a roadmap to the most critical studies needed for polar bear conservation; from energetics to nutrition to reproduction, polar bears in zoos can help fill knowledge gaps that benefit their wild peers.

Bozeman, Montana — January 26, 2022 — Polar Bears International is supporting a team of researchers from leading zoos and aquariums involved in the Polar Bear Research Council (PBRC) in devising a Masterplan to advance the understanding of polar bear biology and management by participating in scientific research that will help protect the world’s polar bears. Today the PBRC released the 2022 PBRC Research Masterplan, a living document that describes the highest priorities for, and most recent findings from, zoo-based polar bear research. Download the Masterplan here.

In 2018, Polar Bears International supported the efforts of the Association of Zoos and Aquariums (AZA) in forming the Polar Bear Research Council (PBRC). Composed of zoo professionals and polar bear researchers, the Council focuses on keeping research current with emerging scientific questions regarding polar bears in the wild within the four main areas: Field Techniques, Health and Welfare, Physiology and Behavioral Ecology, and Reproductive Physiology. Zoos present a unique ability to fill critical knowledge gaps; they can also help develop and calibrate new research methods and technologies before they are deployed in the field. Bears in managed care can be repeatedly observed and sampled over long time periods—allowing sample size and replication not possible in the wild. 

Collaborative efforts to understand and protect polar bears couldn’t come at a more urgent time. The International Union for Conservation of Nature estimates that just 26,000 polar bears remain across their range, which includes the U.S. (Alaska), Canada, Russia, Greenland, and Norway (Svalbard). The polar bears’ continued survival depends on human action to transition away from burning fossil fuels for energy like coal, oil, and natural gas. Zoo-based energetics research in partnership with field researchers was pivotal in the groundbreaking report that if we stay on our current greenhouse gas emissions path, polar bears could disappear by the end of the century

“I’ve spent most of my career conducting research on wild polar bears across the Arctic, which has confirmed the threat of global warming and that we must reduce our reliance on fossil fuels in order to protect future generations of polar bears,” says Steven C. Amstrup, Ph.D., chief scientist at Polar Bears International, adding, “My experience has also shown that some vital studies simply cannot be conducted in the wild, and findings from zoo-based research are crucial to informing population estimates, policy, and more.”

This year, in particular, scientists are making significant headway studying polar bear nutrition, fur growth patterns and reproduction in zoos. Examples of PBRC-endorsed studies recently completed or currently in progress include: 

  1. Better understanding fur growth as a tool for studying the behavior and physiology of wild bears: In a study led by scientists at the University of Washington and the US Geological Survey, polar bears such as Blizzard, a 25-year-old male bear at Point Defiance Zoo & Aquarium, are participating in a fur study in collaboration with San Diego Zoo, Louisville Zoo, Assiniboine Park Zoo in Canada, Detroit Zoo, Oregon Zoo, Old Dominion University, Aarhus University, and Centre College. While fully awake, Blizzard volunteers to have a purple dot dyed on his coat and ingests a non-toxic biomarker (usually contained in some snacks) that is incorporated into the growing hair. Scientists then analyze the rate of fur growth, seasonal timing of hair growth, and the factors that affect these metrics, such as food intake, nutritional condition, size, age, sex, and environmental conditions. Understanding fur growth patterns help scientists better interpret stress levels, contaminant exposure, and the nutritional status using hair samples collected from polar bears in the wild.

  2. Development of new tracking tags: Zookeepers and Veterinary staff are attaching prototypes of new, minimally-invasive, temporary tracking tags that attach to bear fur, developed by 3M and Polar Bears International. Tags have been attached to wild bears and also zoo bears like Kulu, a two-year-old male bear at St. Paul Como Park Zoo. Bears like Kulu live in diverse settings ideal for testing the prototype’s performance under various conditions, gaining critical information about when and why the tags fall off–information that they would be unable to obtain from wild bears roaming in the Arctic. The new tags will help scientists gain insights into polar bear movement patterns and habitat use, linking the contributions of bears like Kulu to the conservation of polar bears in the wild. Zoos participating in the “Burr on Fur” research project include Point Defiance Zoo & Aquarium, Kansas City Zoo, Columbus Zoo and Aquarium, Assiniboine Park Zoo in Canada, San Diego Zoo, Como Park Zoo, Oregon Zoo, Louisville Zoo, and Maryland Zoo in Baltimore.

  3. Improving bear nutrition and health:  Polar bears at Como Zoo, Brookfield Zoo, Columbus Zoo, Detroit Zoo, Seneca Park Zoo, and the Alaska Zoo recently provided critical information on macronutrient requirements of polar bears in collaboration with a study led by the U.S. Geological Survey and Washington State University.  In combination with studies of wild bears, feeding trials with zoo polar bears demonstrated that polar bears have low protein requirements and that maintaining bears on lower protein diets is critical to support long-term kidney health. On higher protein diets, polar bears expend energy excreting nitrogen that exceeds their requirements, thereby increasing energetic costs and taxing the kidneys. This has important implications for interpreting the changing diets of wild bears and ensuring optimal health of zoo polar bears. The studies confirmed that polar bears consume the highest fat diet of any species in the world which supports the high energy requirements needed to support their large body size in an Arctic environment.

  4. Improved understanding of reproduction: Scientists at the Cincinnati Zoo & Botanical Garden are using cutting-edge technology to understand and improve reproduction in polar bears, working with samples from more than 60 polar bears at 31 zoos. Voluntary blood samples are being used to study how the bear’s reproductive hormones fluctuate across the entire calendar year. The findings will help field researchers assess pregnancy in wild polar bears and will also help ensure genetic diversity.

Polar bear at the zoo with purple spots on its fur

Photo: Point Defiance Zoo & Aquarium

Blizzard with dye

These studies contribute to a growing group of PBRC-endorsed research projects that are currently underway:

  1. Comparative analyses of the expression of reproductive steroids and dehydroepiandrosterone sulfate (DHEAS) in captive and wild female polar bears

  2. Characterization of the gut microbiota in polar bears and a metabolic analysis

  3. Development of dynamic energy budget models in complex vertebrate mammals to understand past and future population dynamics

  4. Validation and characterization of reproductive hormones and biomarkers in polar bear serum, including maintaining polar bear sperm banks and fecal banks

  5. Analyzing hormone patterns of captive male polar bears housed under different social conditions

  6. Assessing the timing and rate of fur growth in zoo polar bears

  7. Polar bear ear measurements (for new ear tag tracking device)

  8. Serum concentration comparisons of fatty acids, amino acids, vitamins, minerals, and cholesterol, between free-ranging and zoo polar bears

  9. New attachment techniques for electronics to polar bears – Project “Burr on Fur” 

“Polar bears live on remote and often inaccessible Arctic sea ice, so we’re excited to fill data gaps with our findings from zoo bears. For example, through the innovative and collaborative energetics study, we learned that polar bears use nearly twice as much energy to move about the sea ice than originally thought, ” says Megan Owen, Ph.D., vice president of conservation science at San Diego Zoo Wildlife Alliance and co-chair of the PBRC. “The voluntary participation of our resident bear, Tatqiq, has been invaluable for building our collective knowledge about her species, and ultimately in securing her species’ future.”

“Collaborations like these are essential to polar bear conservation–and it’s immensely gratifying to realize that zoo-based studies can play such a critical role,” says Terri Roth, Ph.D., vice president of conservation and science at the Cincinnati Zoo & Botanical Garden and co-chair of the PBRC. “Our goal with the plan is to provide a clear road map that will help zoos and aquariums fill knowledge gaps and support the key priorities of field researchers.” 

Polar bears in zoos and aquariums play an essential role in conservation research that directly benefits their wild peers. The PBRC’s goals are to: 1) facilitate the use of zoo and aquarium- housed polar bears to better characterize basic biology and to advance scientific methodologies for comparison and application to wild polar bears; 2) support research that is necessary for maintaining a viable, sustainable zoo population for scientific research with application to the conservation of wild bears; and 3) build capacity within member institutions to participate in priority scientific research efforts.  

“We still have gaps in understanding how climate change is affecting polar bears, so it’s essential that the bears in our care help scientists learn more about their species,” says Amy Cutting, interim director of animal care and conservation at the Oregon Zoo and facilitator and contact for the PRBC. “Zoo bears are perfect candidates to help because they already participate in many health-care behaviors voluntarily and seem to find those experiences enriching. In addition to inspiring our guests to take action on behalf of polar bears, they are helping conservationists find ways to save a species facing very serious threats to its survival. I am really proud of how the zoo community has come together over the last decade to make significant contributions to polar bear conservation science.”

About the Polar Bear Research Council 
Founded in 2018, the Polar Bear Research Council (PBRC) is a coalition of North American zoos and research institutions that ensures a robust, thriving zoo population of polar bears is involved in research that produces solutions to conservation and management challenges facing wild bears. The PBRC is co-chaired by Terri Roth, Ph.D. of the Cincinnati Zoo & Botanical Garden and Megan Owen, Ph.D. of the San Diego Zoo Wildlife Alliance. The council includes representatives from the Association of Zoos and Aquariums (AZA), Oregon Zoo, Como Park Zoo, Polar Bears International, Assiniboine Park Zoo, U.S. Geological Survey, and Washington State University. In addition, many of the zoos and aquariums taking part in these studies are part of Polar Bears International’s Arctic Ambassador Center network, working with PBI collaboratively on research, education, and action programs that address the challenges polar bears face in a warming Arctic.

Facilitator and Media Contact: Amy Cutting, Oregon Zoo, email (preferred) Amy.Cutting@oregonzoo.org; cell: 503-757-8163; Office: 503-220-2446 

About Polar Bears International
Polar Bears International’s mission is to conserve polar bears and the sea ice they depend on. Through media, science, and advocacy, we work to inspire people to care about the Arctic, the threats to its future, and the connection between this remote region and our global climate. PBI is the only nonprofit organization dedicated solely to wild polar bears and Arctic sea ice, and our staff includes scientists who study wild polar bears. The organization is a recognized leader in polar bear conservation. For more information, visit www.polarbearsinternational.org.

Media Contacts:

Annie Edwards, for Polar Bears International

Melissa Hourigan, for Polar Bears International
melissa@fabricmedia.net; 720-608-1919

2023 Polar Bear Research Masterplan