Standard Growth Patterns and Variations in Growth Patterns of the Japanese Monkeys (Macaca fuscata) Based on an Analysis by the Spline Function Method

Abstract

The postnatal growth of Japanese monkeys (Macaca fuscata) was analyzed cross-sectionally by the Spline Function method. Growth patterns were expressed by both distance and velocity curves. The entire growth period of the Japanese monkey is composed of four stages: from birth to two years of age when the growth velocity decreases rapidly; from two to three and a half (in females) or four and a half (in males) years of age when the velocity stays constant or growth accelerates; from those ages to eight years of age when the velocity decreases again to zero; and after eight years of age when growth no longer occurs. The sex difference between ages at full maturation is not large. Variations in growth patterns were compared among four groups of Japanese monkeys: the Koshima, Shiga and Yakushima groups and a Standard group. Characteristics of growth patterns were also compared among several species of Cercopithecids.