Abstract
Fecal sites of the Siberian flying squirrel Pteromys volans were found in the 16 tree species, and 11 species (46.4%) of them were used as fecal sites in winter and only 3 tree species (5.6%) were used for their fecal dropping in summer. In winter and spring, 11 and 10 tree species were used as fecal sites, respectively, indicating that various species of trees are used in those seasons for food sources or resting sites of the flying squirrels. Of total 16 species, the flying squirrels' fecal sites were most frequently found in Quercus mongolica (46.4%) and then followed by Prunus sargentii (25.6%). In winter, Prunus sargentii was preferred more than Quercus mongolica, although trees of Prunus sargentii are less distributed compared with those of various trees of the genus Quercus. In summer and autumn, high productivity of trees makes the flying squirrels use only one or two species they prefer. In winter and spring, however, they should extend their food source to various tree species because of low productivity and less food sources.
