Polar Bear Week champions the Arctic"s majestic predator, one of nature"s greatest hunters. Established by Polar Bears International, it highlights the challenges they face due to climate change, particularly the rapid loss of Arctic Sea ice. At this time of year, polar bears gather in Churchill, Canada—known as the "polar bear capital of the world." Here, bears wait for Hudson Bay to freeze so they can start hunting for seals, their primary food source.