White-tailed ptarmigan wings, square-ended tail, small black beak and short legs with feathering extending to the toes. Adults are long, with the males being only slightly larger than the females. The average weight is . During the summer, the white-tailed ptarmigan is a speckled grayish brown with white underparts, tail and wings. In the fall, the plumage has turned a much more reddish-brown color and white feathers begin to grow through. By winter all the summer brown feathers are lost and the bird is completely white. A further molt in the spring precedes the breeding season and the bird returns to its
Winter white dwarf hamster sungorus sungorus". Today Winter white dwarf hamsters and Campbell's dwarf hamsters are considered separate species with the Winter white officially known as "Phodopus sungorus". The coat of the Winter white hamster is less woolly than that of Campbell's dwarf hamster, and apart from the normal colouring, they can be coloured sapphire, sapphire pearl, or normal pearl. The head length of the Winter white hamster is 70–90 mm, the length of the tail is 5–15 mm, and the hind legs are 11–15 mm. The body weight changes dramatically throughout the year. It is at its lowest during the winter. In males,