Relationships among reproductive status, nutritional status, and food characteristics in a natural population of Peromyscus maniculatus

Abstract

We compared digestibility of consumed food, dimensions of the alimentary tract, body fat and body size in relation to sex and reproductive status of overwintered adult Peromyscus maniculatus to assess the applicability of these measures of food intake and nutritional status to natural populations. Nonbreeding females were smaller than other sex and reproductive categories, but they had the largest alimentary tracts and energy reserves for their size. Lactating females were large, but they had low energy reserves and only averaged-sized alimentary tracts. Nonbreeding males ate relatively poor quality foods, had the smallest alimentary tracts for their size, and had low energy reserves. Most of these patterns were interpretable based on the known biology of this population. We conclude that these measures can provide insights into intraspecific variation in food intake and nutritional status in natural populations of Peromyscus.