Появление летяги Pteromys volans L., 1785 (Sciuridae, Mammalia) в заказнике «Озеро Глубокое» (Московская область)

The list of mammals of the Lake Glubokoe Nature Reserve (Ruza district, Moscow region, Russia) was supplemented with the flying squirrel (Pteromys volans). The contemporary border of the native range of the flying squirrel goes through the northeast of the Moscow region. No individuals of this species had been met in the western districts of the region till the end of the 20th century. However, a flying squirrel population has recently appeared in the vicinities of the Zvenigorod biological station of Moscow State University. This population originates from several animals transported to the biological station for scientific purposes. As genetic studies show, individuals from this population belong to the endemic Far-East phylogenetic lineage. The said lineage includes individuals recently met in other places in the western part of the Moscow region. The sequence of cytochrome B gene of mitochondrial DNA from a tissue sample of a flying squirrel individual found on the territory of the Lake Glubokoe Nature Reserve in July, 2013, is identical to that known for animals from the Zvenigorod biological station, MSU, as well as from other places of the western part of the Moscow region. The new record is the westernmost one among all other previous records, which confirms the enlarging of the Zvenigorod invasive subrange of this species. Despite the Pteromys volans population in the vicinities of Lake Glubokoe appeared as a consequence of introduction, it is protected by the Red Data Book of the Moscow region.