Genetic Analysis of Invasive Rats From the Hahajima Islands in the Ogasawara Islands
- 1Biodiversity Division National Institute for Environmental Studies Ibaraki Japan
- 2Hokkaido Research Center Forestry and Forest Products Research Institute Sapporo Japan
- 3Department of Veterinary Medicine Obihiro University of Agriculture and Veterinary Medicine Obihiro Japan
Abstract
Based on mitochondrial DNA (mtDNA) sequences, we concluded that the Hahajima Islands are largely inhabited by Rattus norvegicus (brown rat), except for Katsuodorijima. The previous study reported that the Chichijima Islands were occupied by Rattus rattus complex (RrC) (black rats). We considered that R. norvegicus inhabits the Hahajima Islands owing to a combination of factors, such as climatic differences between the Chichijima Islands and the Hahajima Islands, the timing of the invasion by invasive rodents in the satellite islands of Hahajima, and geographical factors. Based on a comparative analysis of the Chichijima individual of RrC, we concluded that RrC II (corresponding to Rattus tanezumi ) inhabits Katsuodorijima. The previous study reported that RrC II inhabits Hahajima; therefore, we considered that RrC II migrated from Hahajima to Katsuodorijima by swimming because Katsuodorijima is geographically adjacent to Hahajima and can be reached by swimming. In this study, unique haplotypes (CT6, CT8, and TC7) in R. norvegicus at Meijima and Mukohjima, based on the D‐loop analysis, were observed. To the best of our knowledge, these unique haplotypes have not been reported in previous studies; therefore, we considered that these haplotypes originated on Mukohjima and Meijima. Based on this result, although the use of mtDNA data to demonstrate whether migration occurred would be difficult, we suggested that R. norvegicus likely did not migrate from Meijima or Mukohjima to other islands. Invasive rodents severely affect the ecosystems of the Ogasawara Islands, including the Hahajima Islands. Predation of Ogasawara Greenfinch ( Chloris kittlitzi ) nests is a representative problem. This study provides helpful information for promoting effective invasive rodent control on the Hahajima Islands.
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BibTeX
@article{katayama2026genetic,
title = {{Genetic Analysis of Invasive Rats From the Hahajima Islands in the Ogasawara Islands}},
author = {Masafumi Katayama and Kazuto Kawakami and Manabu Onuma and Yusuke K. Kawai},
journal = {Ecology and Evolution},
year = {2026},
month = oct,
doi = {10.1002/ece3.74587},
url = {https://onlinelibrary.wiley.com/doi/10.1002/ece3.74587},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Genetic Analysis of Invasive Rats From the Hahajima Islands in the Ogasawara Islands
AU - Masafumi Katayama
AU - Kazuto Kawakami
AU - Manabu Onuma
AU - Yusuke K. Kawai
PY - 2026
DA - 2026/10/28
JO - Ecology and Evolution
DO - 10.1002/ece3.74587
UR - https://onlinelibrary.wiley.com/doi/10.1002/ece3.74587
AB - Based on mitochondrial DNA (mtDNA) sequences, we concluded that the Hahajima Islands are largely inhabited by Rattus norvegicus (brown rat), except for Katsuodorijima. The previous study reported that the Chichijima Islands were occupied by Rattus rattus complex (RrC) (black rats). We considered that R. norvegicus inhabits the Hahajima Islands owing to a combination of factors, such as climatic differences between the Chichijima Islands and the Hahajima Islands, the timing of the invasion by invasive rodents in the satellite islands of Hahajima, and geographical factors. Based on a comparative analysis of the Chichijima individual of RrC, we concluded that RrC II (corresponding to Rattus tanezumi ) inhabits Katsuodorijima. The previous study reported that RrC II inhabits Hahajima; therefore, we considered that RrC II migrated from Hahajima to Katsuodorijima by swimming because Katsuodorijima is geographically adjacent to Hahajima and can be reached by swimming. In this study, unique haplotypes (CT6, CT8, and TC7) in R. norvegicus at Meijima and Mukohjima, based on the D‐loop analysis, were observed. To the best of our knowledge, these unique haplotypes have not been reported in previous studies; therefore, we considered that these haplotypes originated on Mukohjima and Meijima. Based on this result, although the use of mtDNA data to demonstrate whether migration occurred would be difficult, we suggested that R. norvegicus likely did not migrate from Meijima or Mukohjima to other islands. Invasive rodents severely affect the ecosystems of the Ogasawara Islands, including the Hahajima Islands. Predation of Ogasawara Greenfinch ( Chloris kittlitzi ) nests is a representative problem. This study provides helpful information for promoting effective invasive rodent control on the Hahajima Islands.
SN - 2045-7758
SN - 2045-7758
ER -