official-estonia:

Siberian flying squirrel (Pteromys volans) is the only species of flying squirrel found in Europe. It is under first category protection in Estonia.

The squirrel is pretty small (weighs around 150 grams). Its coat is grey and it has black eyes. A distinctive feature of flying squirrels is the furry glide membrane – a flap of skin that stretches between the front and rear legs. This allows the squirrel to glide from one tree to another.

In Estonia, the squirrels can most often be found from the forests surrounding the bogs of Virumaa and in Soomaa national park.