White-tailed ptarmigan cover. The white-tailed ptarmigan was introduced into the Sierra Nevada of California, Wallowa Mountains in Oregon, and Uinta Mountains of Utah in the 1970s. It may have been native here during the early Pleistocene but became locally extinct due to climate changes with greater snow-cover in spring impacting on its breeding season. Alternatively, it may have been unable to colonize the Sierra Nevada because of the barriers provided by the Columbia River and the Great Basin, and the low altitudes of the intervening South Cascades. This herbivorous bird's diet varies seasonally. Nitrogen-rich snow buttercup leaves are favored in the spring
Winter white dwarf hamster the body weight ranges from , and in females, . In human care, they are slightly heavier. The average lifespan of the Winter white hamster is one to three years in captivity, though they can live longer. In the wild, they are known to live as little as one year. In summer, the fur of the Winter white hamster on the back changes from ash-grey to dark brown, or sometimes pale brown with a tint. The face changes to grey or brown, while the mouth area, the whisker area, and the ears are slightly brighter. The outer ears and the