The Siberian flying squirrel – a symbol of forest conservation

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Finland and Estonia are the only EU Member States in which the Siberian flying squirrel is found with certainty.On the other hand, in global terms it is not threatened, as it is found in an area that ranges from Finland to the Pacific coast and the Korean peninsula. 

The Siberian flying squirrel populates older, spruce-dominated coniferous forests that also contain a mix of deciduous trees – aspen, birch and alder in particular. Old spruce trees provide it with shelter from predators, which include owls, hawks and pine martens.

Breeding sites and resting places spared

In Finland, the Siberian flying squirrel population is at its densest in the south, where commercial forest utilisation has the longest tradition. Forestry guidelines require forest owners to preserve ecological corridors for these animals as well as to refrain from clearing and logging operations in breeding sites and resting places and to leave the soil surface of these areas undisturbed. Logging areas must be planned in a manner, which leaves breeding sites and resting places at the edge of the logging area . Trees, which provide cover and facilitate the movement of these squirrels, are to be left standing at appropriate distances from each other in regeneration areas. Special attention must also be paid to the ability of these retention trees to withstand storm winds. In addition to this, hollow trees in which the squirrels can breed and rest as well as trees that provide shelter and a source of nourishment are left standing in thinning operations.

How to identify a Siberian flying squirrel?

The coat of a Siberian flying squirrel is grey on the back and lighter on the abdomen. The squirrel is less than 20 cm in length, in addition to which its flat tail is 10 – 15 cm long. The nickname “flying mitten” is a surprisingly accurate description of the Siberian flying squirrel’s appearance. A flap of skin called a patagium stretches between the squirrel’s front and hind legs; spreading it allows the squirrel to glide between trees over distances of up to tens of metres. The squirrel rarely moves on the ground and prefers not to cross open areas. The easiest way to identify a Siberian flying squirrel habitat is to look for its golden-brown droppings, which are about the size of a rice grain and can be found under old aspen and spruce trees.

The diet of the Siberian flying squirrels includes catkins, leaves and leaf buds. It most commonly nests in holes made by woodpeckers or in bird boxes, although they sometimes take over abandoned twig dreys of the more common red squirrel. It is not entirely unheard of for Siberian flying squirrels to nest in the attics of summer cottages or outbuildings or some other available cavities either. 

Flying squirrels species found from the tropics to Siberia

The Siberian flying squirrel’s relatives populate, for example, Canada and North America, China, Japan, India and other Asian countries, in addition to which there are several tropical species of flying squirrel. In all, 44 species of flying squirrel have been identified, the largest of which are almost half a metre long, even without their tails, and still they are capable of gliding between trees just like their much smaller northern kin.

The UN has declared 2010 as the International Year of Biodiversity. For the remainder of 2009, this series of articles will examine concepts and phenomena that are related to biodiversity.

Additional information:
Suvi Raivio, Senior Advisor, Biodiversity,
Tel: +358 9 132 6671, +358 40 521 6216