Eradication and Ecosystem Impacts of Rats in the Ogasawara Islands

  • Takuma Hashimoto


Alien rat species have severe negative impacts on ecosystems in many regions, including the Ogasawara Islands. In some cases urgent countermeasures are required, for example, when predation by rats endangers populations of seabirds breeding on uninhabited islands. Some countries, notably New Zealand, have had success eradicating rats from islands using rodenticides. In 2007, we attempted to eradicate the black rat Rattus rattus from Nishijima, in the Ogasawara Islands. We achieved almost complete eradication using bait stations and using diphacinone as a roden-ticide; we were also able to minimize risks to non-target animals and secondary poisoning events. Rodenticide has been broadcast aerially in Mukojima and Higashijima, and we are still monitoring the progress of this program. We will attempt to eradicate more alien rats in the Ogasawara Islands by considering geographical factors, operating conditions, and impacts on non-target animals.


Land Snail Bait Station Eradication Campaign Ogasawara Island Clapper Rail 
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I thank Dr. Shun'ichi Makino at the Forestry and Forest Products Research Institute and Dr. Tatsuo Yabe at Rat Control Consulting for much useful advice, and I thank local residents of Ogasawara village for their cooperation with and understanding of our rat eradication campaigns. Rat eradication in Nishijima was conducted as a part of the project “Studies on eradication of introduced species and the recovery of ecosystems in the Ogasawara Islands,” and eradications in Mukojima and Higashijima were conducted as a part of “Control program of black rats for restoration of natural habitats in the Ogasawara Islands” sponsored by the Kanto Regional Environment Office of Ministry of the Environment.


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Copyright information

© Springer 2010

Authors and Affiliations

  1. 1.Japan Wildlife Research CenterTaito-kuJapan

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