Effects of reproduction on maternal survival and subsequent reproduction in northern <i>Peromyscus maniculatus</i>

Abstract

Female survival, number of young weaned, and offspring survival were documented for 130 individual Peromyscus maniculatus in the Kananaskis Valley, southwestern Alberta. Reproductive success was highly variable, ranging from 0 to 19 young per female at weaning and from 0 to 12 young per female at the end of the breeding season. Breeding success was not related to body size of the female prior to breeding, and the commitment to reproductive processes had no negative effects on female survival or the survival of the offspring. Most of the variation in reproductive success was attributable to female survival. Females that survived the entire breeding season weaned, on average, twice as many young as females that did not survive the breeding season. We suggest that physiological and behavior compensation and local habitat effects mask potential costs of reproduction during the breeding season. We speculate that any negative effects of high reproductive success may be evident during the nonbreeding season, or prior to breeding in the spring.