Observations on Chipmunks and Mantled Squirrels in Northeastern California

Abstract

During an investigation into the influence of rodents on reforestation, the Division of Zoology of the University of California iat Davis trapped, autopsied, and studied 1,340 chipmunks and mantled squirrels. This work was done in cooperation with the California Forest and Range Experiment Station of the United States Forest Service. Its aim was a better understanding of the biology of diurnal rodents which, primarily because of their seed-eating habits, are accused of hindering reforestation. This paper gives selected facts and conclusions which resulted from the survey. Food data were analyzed separately. Trapping started in mid-September of 1950 and ended one year later. Chiefly it was restricted to the Quincy area, which includes mountainous, coniferous terrain within thirty miles of the town of Quincy in Plumas County of northeastern Califonia. Four species of chipmunks (Eutamias amoenus, speciosus, townsendii, and quadrimaculatus) and the mantLed squirrel (Citellus lateralis) constitute a population unit of the important diurnal rodents of the area at altitudes from 4,500 to 5,500 feet, but numerical ratios between them differ with habitat.