Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 2014/04 -2016/03
Author : Kaji Koichi; YOSHIDA TSUYOSHI; KUBO MUGINO; IGOTA HIROMASA; NAGATA JUNCO; UENO MAYUMI
To clarify the processes and mechanisms behind insular evolution of sika deer, we surveyed chronological change in life history, morphology and genetics of an introduced island population. Under resource limitation, the female sika deer exhibited delayed sexual maturity from yearlings to 3 years old and lower body mass when population density increased. After population reduction, the first age of pregnancy was advanced from 3 years old to 2 years old and body mass of adult female increased. Corresponding to changes in food, molar wear rate became faster after the first population crash. The size of molar dentition once decreased, however, increased thereafter. Effective population size as well as genetic diversity had once decreased, however, thereafter stabilized and increased, respectively. Theses results suggest the possibility of positive natural selection for morphology and genetics in the insular sika deer under resource limitation.