evidence: - Andrew Derocher, Jan. 17, Email exchange with USA TODAY interviewed him but a quote didn't make the cut - Dag Vongraven, Jan. 18, Email exchange with USA TODAY - Ecological Applications, Jan. 10, 2020, Interrelated ecological impacts of climate change on an apex predator - International Union for Conservation of Nature, 1966, Proceedings of the first international scientific meeting on the polar bear - International Union for Conservation of Nature, 1985, Polar bears: proceedings of the eighth Working Meeting of the IUCN/SSC Polar Bear Specialist Group, held at the Ministry of Environment, Oslo, Norway, 15-19 January 1981 - Polar Bear Specialist Group, July 2021, Status Report on the World’s Polar Bear Subpopulations - John Whiteman, Jan. 20, Phone interview with USA TODAY - Kristin Laidre and Nicholas Lunn, Jan. 20, Email exchange with USA TODAY - NASA, Feb. 4, 2020, Polar Bears Struggle as Sea Ice Declines - Polar Bears In Canada, accessed Jan. 20, Guided Hunting in Canada - Polar Bear Range States, accessed Jan. 20, The 1973 Agreement on the Conservation of Polar Bears - Steven Amstrup, Jan. 17, Email exchange with USA TODAY - AFP, Jan. 13, Graph on polar bear population uses unreliable data