Prediction of energy expenditures by Rocky Mountain bighorn sheep

Abstract

Factors influencing the metabolic rate of two adult male and two adult female Rocky Mountain bighorn sheep (Ovis canadensis) were analyzed by multiple classification analysis. Factors considered were sex, date, body weight, exposure temperature, adaptation temperature, time since last feeding, and previous gross energy intake. The overall mean energy expenditure was 11.012 MJ∙day−1 (460 kJ∙kg−075∙day−1). When factors were tested independently, body weight, sex, and exposure temperature, in order of importance, contributed significantly to differences in energy expenditures. The total statistical model accounted for 87% of variance. Metabolic rate increased with body weight and previous gross energy intake and decreased with adaptation temperature, exposure temperature, and fasting. Metabolic rates of males were higher than of females. An underlying seasonal cycle in resting metabolic rate was observed.