Gliding ability of the Siberian flying squirrel Pteromys volans orii

Abstract

Forest fragmentation is a threat to flying squirrel population due to dependence on gliding locomotion in forests. Therefore, it is essential to understand their gliding ability. The gliding locomotion of Pteromys volans orii, were observed from July 2003 to June 2005, in Obihiro, Hokkaido, Japan. The horizontal distance and glide ratio obtained from 31 glides were employed as indicators to know their gliding ability. The gliding ability was not affected by weight and sex in the Siberian flying squirrel. Mean horizontal distance and glide ratio were 18.90 m and 1.70 with great variation. Although maximum values were 49.40 m (horizontal distance) and 3.31 (glide ratio), most of the horizontal distance and glide ratio were in the ‘10–20 m’ and ‘1.0–1.5’, respectively. Therefore, to retain the flying squirrel populations, forest gaps should not exceed the distance traversable with a glide ratio of 1.0 (distance between forests/tree height at the forest edg).