Abstract
Seasonal changes in growth and food consumption of captive deer mice Peromyscus maniculatus, caged in a seminatural environment were measured at Lethbridge, Alberta, Canada. Significant decreases in growth and in weight-specific food consumption occurred in winter months. Daily caloric consumption was not significantly lower in winter than in the fall but increased significantly in spring concurrently with both significant increases in weight and weight-specific food consumption. Results are discussed relative to the need for conservation of energy in winter and the contribution reduced growth and activity could make toward such a saving.