Abstract
Age-related body weight changes, winter body weight changes and breeding condition of free-ranging sika deer and captive sika deer, which had the same genetic origin and different nutritional conditions, were surveyed. The adult male reached around 75 kg in body weight and the adult female reached around 50 kg, and they showed an apparent difference of sexual demography. The captive deer under yearlong good food condition showed large body weight increase until winter of yearling and the free-ranging deer under yearlong poor food condition kept large body weight increase until winter of two-years old. The body weights at birth were not different significantly each other, but the body weight gains from the birth to the beginning of first winter and the mean birth date were different between free-ranging deer and captive deer. The body weight increase and sexual maturation of free-ranging deer delayed about a year compared with those of the captive deer. The winter weight changes also showed different patterns each other, especially in the case of young deer and pregnant deer. Above results suggest that poor food condition may delay body growth during the period of development and sexual maturation on sika deer.
