Growth in length and weight of northern brown bears: differences between sexes and populations

Abstract

Growth curves were fitted to data on age, length, and spring weight for individuals from three populations of the brown bear, Ursus arctos, in northern Canada and northwest Alaska. Females reached 90% of asymptotic length before sexual maturity and before the age of first production. Their weight remained approximately in proportion to the cube of their length. Males reached 90% of asymptotic length 0.7 to 1.7 years later than females, and had asymptotic lengths 10–15% greater. Males continued their growth in weight even longer, and reached asymptotic weights 80–100% greater than females. Variation between these populations was small compared with the total range of variation in the species.