Indexes of Condition for Small Mammals

Abstract

Estimates of body condition in mammals may be constructed from measures of skeletal size and body mass. We illustrate the methodology for doing this using data from two populations of feral house mice (Mus domesticus) in Australia, and point out an erroneous method that has commonly been used in the literature. Indices of condition for individual house mice were not correlated with the fat content of their carcasses. Indices of condition for house mice have a relatively low repeatability because of variation from day to day in body mass and because of variation in length measurements taken by different observers. Bias in measurements among observers must be eliminated to make indices of condition from live animals useful.