Red-Backed Mice

(Clethrionomys), a genus of rodents of the subfamily Microtinae. Body length, up to 16 cm; tail, up to 6 cm. In contrast to most field mice, red-backed mice have molars with roots. There are eight species found in mountainous and plains forests of Eurasia and North America. Four species inhabit the USSR: Clethrionomys glareolus, C. rutilus, C. rufoca-nus, and C. frater. Red-backed mice are active throughout the year, feeding chiefly on seeds and shoots of trees and bushes. Young are born up to three times annually, with five to seven per litter. They serve as food for the commercially significant muste-lids, damage forestry rehabilitation, and are a natural carrier of the cause of encephalitis.