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 fox pads are covered in fur. There are two genetically distinct coat color morphs: white and blue. In the winter the white morph is white in color and turns brown along the back with light grey around the abdomen in summer. The blue morph is often a dark blue, brown, or grey color year-round. Although the blue allele is dominant over the white allele, 99% of the Arctic fox population is the white morph. The fur of the Arctic fox provides the best insulation of any mammal. The fox has a low surface area to volume ratio, as evidenced by its