Polar Bears Film Their Own Sea Ice World

This clip garnered the most views ever for the USGS on YouTube, just over 400,000, and still growing. A just-published study in Science used videos recorded in 2014-2016 to shed more light on how much food polar bears need to survive.

Although being able to glimpse these remarkable animals as they navigate their sea ice world was fascinating, the videos had a specific research function: USGS researchers, led by Anthony Pagano, were trying to learn about the behaviors and foraging rates of polar bears on the sea ice so ultimately, they could better understand how much food the bears need to be healthy and survive. Up until 2014, most of our understanding of polar bear behavior as they roamed the sea ice were from direct observations made by Dr. Ian Stirling more than 40 years ago and from observations made by coastal indigenous residents.

By equipping the GPS collars with a video camera, the research team were able to link high resolution location data with the actual behavior and foraging success recorded by the camera. This combination enabled scientists to begin to understand the activity patterns of polar bears, for example how often they hunt, eat, rest, walk, and swim and how these behaviors may be affected by sea ice conditions and other variables. New batches of POV video and GPS location data collected in 2015 and 2016 contributed to Pagano’s research.

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The data collected during those years allowed Pagano and his team of scientists to examine the energetic rates and nutritional demands of these animals. In this study, researchers developed a way to measure a polar bear’s metabolic rate, or, said more simply, they discovered how many seals a polar bear needs to eat in order to survive. Their research also suggests that increases in movement rates resulting from reductions in sea ice could greatly increase the energy demands of these animals. This idea is based on inferences drawn between Pagano’s research and previous independent research on habitat loss and polar bear movements to suggest that it is becoming more challenging for polar bears to capture prey because the sea ice platform they use to forage off is available for a shorter time during the year.

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Despite being sit-and-wait predators, the videos and data showed that the measures of activity were in line with other terrestrial carnivores. The study also revealed that the day-to-day activities of polar bears are 60 percent more energetically costly than previously assumed.

The new paper, “High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear,” appears in the journal Science. It is authored by Pagano, along with his USGS co-authors George Durner, Karyn Rode, Todd Atwood, and Elizabeth Peacock; University of California, Santa Cruz researchers Terrie Williams and Daniel Costa; Stephen Atkinson of Dugald, Manitoba; and Megan Owen at the San Diego Zoo Institute for Conservation Research.

Special thanks to Mehdi Bakhtiari for developing the collars used in this study. This work was supported by the U.S. Geological Survey’s Changing Arctic Ecosystems Initiative. Additional support was provided by Polar Bears International; World Wildlife Fund (Canada); San Diego Zoo Global; University of California, Santa Cruz; and the International Association for Bear Research and Management.