Siberian Flying Squirrel

A female Siberian flying squirrel weighs about 150 g (5.3 oz), the males being slightly smaller on average. The body is 13–20 cm (5.1–7.9 in) long, with a 9–14 cm (3.5–5.5 in) long flattened tail. The eyes are large and strikingly black. The coat is grey all over, the abdomen being slightly lighter than the back, with a black stripe between the neck and the forelimb. A distinctive feature of flying squirrels is the furry glide membrane or patagium, a flap of skin that stretches between the front and rear legs. By spreading this membrane the flying squirrel may glide from tree to tree across distances of over a hundred meters, and have been known to record a glide ratio of 3.31, but is normally 1-1.5.

The nominate subspecies, P. v. volans is widespread across the Palearctic realm, specifically in Northern Europe, Siberia and East Asia, while other subspecies have limited distribution, with P. v. athene in Sakhalin, P. v. buechneri in China and P. v. orii in Hokkaido.

They mate early in the spring. In southern Finland the first mating season begins in late March, with a second mating season occurring in April. After a gestation period of five weeks, the female gives birth to a litter of usually two or three young, each weighing about 5 grams.

It is the emblem of Nuuksio National Park in Espoo municipality of Finland due to the density of the population in this region. In Estonia, the Siberian flying squirrel is depicted on the logo of the Estonian Nature Fund.