Laboratory Evaluation of Competition Between Three Species of Rodents

Abstract

Data on interspecific behavioral interactions between the cotton rat (Sigmodon hispidus), pygmy mouse (Baiomys taylori) and the fulvous harvest mouse (Reithrodontomys fulvescens) was collected from 1 September 1980 through 1 April 1981 at the Department of Wildlife and Fisheries Sciences, Texas A & M University. Behavioral interactions were observed in 36 interspecific pairings to determine dominance and subordinance of each species. Pairings included all possible species and sex combinations. Nine behavioral categories were observed and classified as aggressive or submissive behaviors. The cotton rat was significantly (p<0.005) more aggressive when paired with the pygmy mouse or the fulvous harvest mouse. The pygmy mouse was significantly (p<0.005) more aggressive when paired with the fulvous harvest mouse. The length of time an individual was held in captivity had no effect on the frequency of aggressive or submissive behaviors, and the frequency of aggressive or submissive behaviors did not vary significantly (p>0.1) among pairings involving the same two individuals.