Reproduction of female sika deer in Western Japan

Abstract

We describe the reproductive characteristics of female sika deer as determined from fetuses in hunter-killed samples from Hyogo Prefecture, Honshu Island in southwestern Japan, and from similar samples from Kumamoto Prefecture in Kushu Island, the southwestern-most main island in Japan. No fawns were pregnant in either sample. In Hyogo 76.6% of yearling and 89.4% of older females were pregnant, as compared to 84% and 92% for Kumamoto. The pregnancy rate did not decline with age of female in either population. Fetal development is described. Reproductive parameters were similar to those of populations in other parts of Japan. However, timing varied from northeast to southwest, with the latest birth times and shortest duration of fawning occurring in Hokkaido. The timing of fawning was correlated with a warmth index used to describe vegetation growth, with fawning being later in the north and at higher elevations.