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Polar bears predators and preys8/9/2023 ![]() ![]() One surprise was finding high densities of bears concentrated in Russian waters between Wrangell Island and the Chukotka Peninsula. “Our abundance estimate (3,435–5,444 bears) was of similar magnitude to densities extrapolated from the Kotzebue, Alaska region, but differed in where bears were predicted to be. The survey has already yielded new findings that increase our understanding of Chukchi Sea polar bears. From these data they created models relating bear and track densities to environmental factors such as sea ice extent to predict abundance and distribution throughout the study area. The team combined infrared imagery with digital photography and direct visual observation to detect and identify bears, bear tracks, and seals. Until this survey, it had never been used to detect free ranging polar bears. Infrared technology has previously proven highly effective for surveying seals on sea ice. In this study, researchers used thermal cameras to detect the warm bodies of animals on sea ice. But it allows us to look at their distribution over sea ice simultaneously with that of their seal prey,” Conn said.īut it is not easy to spot a white bear in a vast icescape. “During spring, bears are scattered over a larger area, making them more difficult to survey. In this study, the team used long-ranging airplanes to conduct surveys in the spring.Ĭamera array aboard a U.S. Many polar bear aerial surveys are conducted in late summer and early fall, when there is less sea ice and bears are concentrated in smaller areas. Aerial Spring Surveys and Innovative Technology To better understand the distribution and abundance of Chukchi Sea polar bears and their ice seal prey, a new survey approach was needed. airspace and limited in spatial coverage. Previous Chukchi Sea aerial surveys were restricted to U.S. We didn’t have a great idea how reliable such extrapolations were in representing the entire subpopulation.” “Most of the previous work involved intensive studies of polar bears in small areas, with findings extrapolated to much larger areas (using data from adult females tagged near Kotzebue, Alaska, for instance). “Before this study, there was limited understanding of the distribution and abundance of this subpopulation,” Conn said. This collaborative, innovative research opens new possibilities for monitoring mammals that range over the vast, remote Arctic, and across international borders.īlood on the ice and polar bear tracks are evidence of a seal kill site in an aerial photograph. For the first time, they used infrared technology to detect free roaming polar bears. and Russian scientists conducted the first aerial survey to estimate abundances of polar bears and their ice seal prey over the entire Chukchi sea region. Fish & Wildlife Service and Russian partners, we had an opportunity to maximize our resources by simultaneously surveying polar bears.” “Our initial plan was to survey ice seals” said study leader Paul Conn, research statistician at NOAA Fisheries’ Alaska Fisheries Science Center. Results from a joint aerial survey are helping us understand how they’ll respond to these changes- critical information for their conservation and for the subsistence communities that rely on them. ![]() Climate change is rapidly diminishing their sea ice habitat. Polar bears and seals know no international boundaries. ![]()
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