Abstract
The Japanese flying squirrel, Pteromys momonga, is known to prefer the bark of Japanese cedar, Crytomeria japonica, as a nest material in their natural habitats. The present study was conducted to examine the heattrapping capacity of wood fibers from the squirrels’ nests made of the Japanese cedar bark and the bark of Japanese cypress, Chamaecyparis obtusa, and any morphological differences between the cedar nest and cypress nest fibers. The results suggest that cedar fibers have a greater heat trapping capacity than cypress fibers and that cedar nest fibers are longer and finer than cypress nest fibers.
