Arctic ghost, Muskox (Ovibos moschatus) in ice fog in winter, Dovrefjell National Park, Norway. We spent hours looking for the muskoxen on this particular morning... the ice fog was so thick we could not see 100 m in front of us. We had spent about 9 days already on this particular slope with the muskoxen, but we did not know exactly where we were for about 15 minutes. When everything around you is white and your sight distance is very, very limited you can fail to recognize things because the larger context of the landscape simply is not there. Fortunately our confusion did not last long. The ice fog started to lift allowing us to see further, but then the fog rolled back over the landscape. This allowed for the image below; a male muskox, barely visible in the ice fog. Muskoxen evolved in Asia and adapted to arctic tundra environments. Muskoxen became extinct in Europe (last records are from Sweden about 9,000 years ago) and Asia (last records are from the Taymyr peninsula in Russia about 2,000 years ago), probably primarily as a result of over hunting by people. Muskoxen crossed into North America from Siberia between 200,000 and 90,000 years ago and they survived in Alaska, northern Canada and Greenland. Muskoxen were reintroduced in Europe and Asia relatively recently. Muskoxen were first reintroduced in Dovrefjell National Park in Norway in 1931-1932, but these animals were all killed during the second world war. A second reintroduction attempt (1947-1953) was successful though. The muskoxen population size in Dovrefjell National Park is currently estimated at several hundred individuals.