Where does rock Ptarmigan usually live？

The rock ptarmigan is a sedentary species which breeds across arctic and subarctic Eurasia and North America (including Greenland) on rocky mountainsides and tundra. It is widespread in the Arctic Cordillera and is found in isolated populations in the mountains of Norway, Scotland, the Pyrenees, the Alps, Bulgaria, the Urals, the Pamir Mountains, the Altay Mountains, and Japan—where it occurs only in the Japan Alps and on Hakusan mountain. Because of the remote habitat in which it lives, it has only a few predators—such as golden eagles—and it can be surprisingly approachable. It has been introduced to New Zealand, South Georgia, the Kerguelen Islands, and the Crozet Islands. The small population living on Franz Josef Land in the Russian High Arctic overwinters during the polar night and survives by feeding on rich vegetation on and underneath high cliffs where seabird colonies are located in summer. During the last ice age, the species was far more widespread in continental Europe.