Acorn Consumption by Chipmunks and White-Footed Mice

Abstract

During the course of an investigation of factors affecting oak mast production, considerable attention was directed toward determining the biotic agencies responsible for the utilization of the fall acorn crop. Particular emphasis was focused on the possible influence of certain small mammals in competing with game animals for this food. In order to adequately interpret the extent of acorn competition, a controlled feeding study was initiated in mid-October, 1952, and continued to mid-November. Five wild eastern chipmunks (Tamias striatus rufescens) and four white-footed mice (Peromyscus leucopus noveboracensis) were live-trapped in the vicinity of East Lansing, Michigan, for use as test animals and confined in cages. Four species of acorns, previously collected and examined for soundness, were the only food available during the tests, and these were fed periodically depending upon the quantity of uneaten food remaining. During the aggregate 98 chipmunk-days of feeding, the average consumption was 6.1 acorns per animal per day, based on a total of 600 acorns eaten (Table 1). Only slight variations from this mean were noted; a high daily average of 6.8 acorns for one animal was probably the result of greater energy expenditure, since this animal had use of a rotary exerciser cage. The lowest individual consumption, averaging 5.3 acorns per day, appeared to result from a distaste for red oak (Quercus rubra) acorns rather than a lower food requirement.