Verification of the effect of whole island extermination of exotic rats in Ogasawara Islands

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06085
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39060:Conservation of biological resources-related
• Research Institution: Yamagata University
• Principal Investigator: Tamate Hidetoshi 山形大学, 学内共同利用施設等, 学長 (90163675)
• Co-Investigator(Kenkyū-buntansha): 兼子 伸吾 福島大学, 共生システム理工学類, 准教授 (30635983)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 分子系統地理 / 遺伝学的集団 / 外来種

Outline of Final Research Achievements

To understand the population structure and genetic interactions of rodents in the Ogasawara Islands, we conducted genetic analyses of individuals captured in 15 areas in the Chichijima and Hahajima archipelagos. Mitochondrial DNA analysis showed that R. rattus is distributed in the northern part of the archipelagos, R. rattus and R. tanezumi in the eastern and central parts, and R. tanezumi in the southern part. A population structure with large divergence between the northern and southern parts was detected in the nuclear gene. This result suggests that the two introduced lines may have interbred and then formed a subpopulation structure through isolation or reduction in population size.

Free Research Field

生物多様性

Academic Significance and Societal Importance of the Research Achievements

本研究では小笠原諸島の生態系に大きな影響を及ぼしている侵略的外来種のクマネズミの分布拡大プロセスを明らかにすることを目的にした。各島で捕獲された個体の遺伝子を調べたところ、父島諸島では起源が異なる2系統の交雑が進んでいること、父島諸島と母島を含む調査地域では島を越えた個体の移動が過去にあった可能性が示された。これらの結果は駆除事業を策定する際に基礎資料として活用できると考えている。