Breeding by Peromyscus in seasonal environments

Abstract

Reproductive characteristics of Peromyscus maniculatus in Manitoba and Peromyscus leucopus in Ontario were compared in order to determine the extent to which breeding compensates for relatively short breeding seasons. Peromyscus maniculatus had a shorter breeding season than P. leucopus, but frequency of litters, litter size, and age of females at sexual maturity were the same for both species. A comparison of breeding characteristics among Peromyscus from different geographic areas indicated that basic reproductive characteristics do not vary in relation to length of the breeding season.In general, we have no evidence that the basic reproductive characteristics of Peromyscus vary in relation to length of the breeding season. Peromyscus with short breeding seasons, on average, must have a lower annual reproductive rate than Peromyscus with long breeding seasons.