Energy requirements during reproduction of Peromyscus maniculatus

Weight-specific food consumption, gross daily energy consumption, and weights of breeding groups, lactating females, and young litters were monitored between time of mating and 2 weeks after weaning. No observable changes in weight-specific or gross daily energy consumption was evident in the 3 weeks before the week in which birth occurred, although weights of females had by then increased an average of 36%. Gross daily energy consumption increased by 96%, 136%, and 194%, respectively, during the 1st, 2nd, and 3rd weeks after birth. Weights of females dropped significantly in the week before weaning.