Happy International Polar Bear Day! For 21 years, conservation nonprofit Polar Bears International has celebrated these vulnerable bears with a day of conservation action and learning. But it was the amazing adaptations polar bears evolved that kept me fascinated by this species of bear for so many years.”Browse through some of his exciting polar bear photographs below. Image: © Daniel J. Cox/NaturalExposures.comOn International Polar Bear Day, Polar Bears International is encouraging people to take part in live scientist chats, check out their northern lights live cam, and track polar bear moms across Hudson Bay. To track the mother bear who adopted a cub this winter, follow bear X33991 on the tracker.