White-tailed ptarmigan listed as "Vulnerable". This bird serves as an indicator species for the alpine tundra, and denotes overall ecosystem health. It is not a conservation concern and is abundant in alpine zones across North America, indicating that this region is not undergoing dramatic climatic, temperature, or precipitation shifts. The lack of overgrazing by cattle, the lack of human development in alpine zones, the difficulty in accessing its remote habitat, the low densities at which it occurs and the laws regarding the limits to hunting bags allow the white-tailed ptarmigan to thrive. White-tailed ptarmigan The white-tailed ptarmigan ("Lagopus leucura"), also known as
Arctic ice pack Arctic ice pack The Arctic ice pack is the sea ice cover of the Arctic Ocean and its vicinity. The Arctic ice pack undergoes a regular seasonal cycle in which ice melts in spring and summer, reaches a minimum around mid-September, then increases during fall and winter. Summer ice cover in the Arctic is about 50% of winter cover. Some of the ice survives from one year to the next. Currently 28% of Arctic basin sea ice is multi-year ice, thicker than seasonal ice: up to thick over large areas, with ridges up to thick. As well as the regular