© Kt Miller/Polar Bears International
5/6/2020 5:34:21 PM
A Tale of Wild and Zoo Polar Bears
By Dr. Thea Bechshøft, Staff Scientist
My field work with wild polar bears has taken me from the sea ice in Svalbard to coastal communities in Greenland and across the Canadian North. But I’ve discovered that, sometimes, answers to critical polar bear questions can be found closer to home.
For more than a decade, Polar Bears International has partnered with zoos in North America on research projects that would be impossible to conduct with polar bears in the wild. Such studies have yielded valuable insights that can directly help their wild peers—from documenting the polar bear’s hearing range to testing their energy use and how they find mates.
From my base in Denmark, I’ve been able to expand PBI’s collaborative research to zoos in Europe. Recently, for example, I helped with a study led by veterinary and PhD student Anna Hein of the Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, and Tiergarten Nürnberg, Germany.
The study by Anna and team lays important groundwork for using polar bear scat to assess the concentration of steroid hormones in the bears. Polar bears and most other mammals produce steroid hormones when experiencing stress brought on by either real (e.g. fasting) or perceived (e.g. social stress) threats. The bears eventually excrete the hormones with other waste, allowing us to measure their concentration in samples picked up off the ground.
Polar bear keepers from a number of accredited zoos (including three of PBI’s Arctic Ambassador Centers: Munich Zoo Hellabrun, Ouwehands Zoo, and Vienna Zoo) collected scat samples from their bears over multiple years. During the process, they noted any events that could potentially be considered stressful for the bears such as a fight, separation, or disease. After statistical analysis on the sample and event data, it became clear that most of the events considered potentially stressful to the bears were indeed reflected in higher hormone concentrations in the samples.
Why is this important? Being able to measure stress levels in polar bears in zoos could contribute significantly to their health and welfare—for example, in relation to their enclosure or social group composition. However, the data also has implications for research on wild bears: not only does it provide valuable, detailed knowledge on the protocols for scat sample collection and hormone analysis, but it also provides data that tells us that correctly collected scat samples—in combination with data on e.g. body condition, reproductive success, diet, or local sea ice condition—can be used to assess the hormonal health status of polar bear populations around the Arctic.
Anna Hein performs steroid hormone extractions in the lab. ©Anna Hein
The kind of zoo-based conservation research described above requires careful planning and a great team on all sides, from researchers to animal care staff. So far, the main animal facilities to participate in these collaborative research efforts have been North American. However, Polar Bears International is now helping to expand the collaborative scope to also include European institutions such as those that helped Anna collect the needed samples for her study.
“It was a great experience to see so many zoos participate,” said Anna. ”This project is an excellent example of how zoos can make an important contribution to wildlife research and conservation by collecting easily accessible samples. Our study provides another useful piece to the puzzle of polar bear endocrinology and health monitoring—and helps push the field forward as it raises new questions."
Over the past few years, PBI has facilitated several meetings and workshops in Europe, bringing together European zoo directors, curators, veterinarians, and polar bear keepers—all with the goal of furthering collaborative conservation-relevant research that benefits conservation of polar bears in the wild. And the added benefit? The daily training sessions that eventually allow the zoos to collect voluntary samples also allow zoo vets to more easily assess the health of their bears, plus it enriches the day for the bear, thereby increasing their general welfare!
For more details on the study, including methodology, read the paper here.