Willow ptarmigan a reddish hue to the neck and breast, a black tail and white wings and underparts. It has two inconspicuous wattles above the eyes, which become red and prominent in the breeding season. The female is similar in appearance but lacks the wattles and has brown feathers scattered among the white feathers on the belly. During winter, the plumage of both sexes becomes completely white, except for some black feathers in the tail. Immature birds resemble the adults. The willow ptarmigan can be distinguished from the closely related rock ptarmigan ("Lagopus muta") by its larger size and thicker bill and
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