Determine the insular process and mechanism of sika deer based on ecology, morphology and genetic information

2015 Fiscal Year Final Research Report

• Project/Area Number: 26650157
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Ecology/Environment
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Kaji Koichi 東京農工大学, (連合)農学研究科(研究院), 教授 (70436674)
• Co-Investigator(Kenkyū-buntansha): YOSHIDA TSUYOSHI 酪農学園大学, 農食環境学群, 教授 (00458134) ; KUBO MUGINO 東京大学, 新領域創成科学研究科, 助教 (10582760)
• Co-Investigator(Renkei-kenkyūsha): IGOTA HIROMASA 酪農学園大学, 農食環境学群, 准教授 (60515857) ; NAGATA JUNCO 独立行政法人森林総合研究所, 鳥獣生態研究室, 主任研究員 (10391179) ; UENO MAYUMI 地方独立行政法人北海道立総合研究機構, 環境科学研究センター 自然環境部保護管理グループ(道東地区野生生物室), 研究主任 (00543753)
• Research Collaborator: 山村 光司 農研機構, 農業環境変動研究センター ; 竹下 和貴 東京農工大学, 博士課程
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 個体群 / 島嶼化 / 生活史特性 / 形態 / 遺伝

Outline of Final Research Achievements

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.

Free Research Field

生物学