Rattus rattus

Basic information
Scientific name	Rattus rattus	Click to magnify
Major synonym	Rattus tanezumi
Common names	Black rat，Roof rat, oriental house rat
Higher taxon	Muridae, Rodentia, Mammalia
Natural range	Ambiguous. Given that there were fossil records of Late Pleistocene and Holocene from Honshu Is., populations on a part of the Japanese mainland should be native.
Habitat	In and around buildings in urban area, farm area, etc. In upper space in highly urbanized area, this species is more dominant than Rattus norvegicus. But, this species occur also in forest on small islands of Izu Islands, Ogasawara (Bonin) Islands, Ryukyus, and others.

Invasion information
Range in Japan	Although natural geographic range is unknown, this species is established on many peripheral islands.
Origin	Unknown.
Date	Introduction to Ogasawara is estimated to be in 1920s.
Route	Accidental: Hitchhiking on some transport.
Impact	Actually: Predation on plants, sea birds, sea turtles, and land snails. Competiton with herbivorous animals. Damage on agriculture. Carrying parasites including zoonosis. Damage on endangered plants and interference of forest regeneration by predation on seeds. Native organism(s) affected: Birds such as Oceanodroma tristrami, Apalopteron familiare, Synthliboramphus wumizusume in Kyashima Is., Fukuoka Pref., Bulweria bulwerii and Puffinus pacifious in Ogasawara (Bonin) Islands. Plants such as Lobelia boninensis in Ogasawara (predation). Birds such as Columba janthina, Carduelis sinica in Ogasawara (competition).
Regulation in Japan	No action for prevention, mitigation, control, or eradication.
Introduced range in other countries	Worldwide

Reference

Notes

Abe et al. (1994) A Pictorial Guide to the Mammals of Japan. Tokai University Press, Tokyo. (in Jpn)
Courchamp et al. (2003) Mammal invaders on islands: impact, control and control impact. Biol. Rev. Camb. Philos. Soc. 78:347-383.
Ecol Soc Japan (ed) (2002) Handbook of Alien Species in Japan. Chijin-Shokan. (in Jpn)
Kawamichi (ed) (1996) Encyclopedia of Animals in Japan 1, Mammals 1. Heibonsha. (in Jpn)
Kaneko (2006) The Taxonomy of Japanese Muridae (Mammalia, Rodentia): From the View Point of Biogeography. University of Tokyo Press, Tokyo. (in Jpn)
Long (2003) Introduced mammals of the world: their history, distribution, and influence. CABI Publishing.
Motokawa et al. (2006) Comparison of species names of Japanese mammals between “A Guide to the Mammals of Japan” and “Mammal Species of the World, Third Edition”. Mammal Sci. 46(2):181-191. (in Jpn, Eng abstract)
Nakamura (1988) Alien Animals of Japan. Kanagawa Pref. Mus., Yokohama (in Jpn)
Nakamura et al. (2002) A Survey on Leptospiral Reservoir Animals in Okinawa Prefecture. Ann Rep. Okinawa Pref. Inst. Health Env. 36:39-42. (in Jpn, Eng abstract)
Ohdachi et al. (eds) (2009) The Wild Mammals of Japan. Shokado, Kyoto.
Wilson & Reeder (eds.) (2005) Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), Johns Hopkins University Press, 2,142 pp. (http://www.press.jhu.edu).
Yabe (2006) “Water rat” of Ogasawara. Annual Reports on Ogasawara Research, Tokyo Metropolitan University. 29:19-22. (in Jpn)
Yamada et al. (eds) (2011) Invasive Alien Mammals in Japan: Biology of Control Strategy and Conservation. Univ. Tokyo Press (in Jpn)

100 of the World’s Worst Invasive Alien Species

East, Southeast, and South Asian populations including the Japanese ones are sometimes regarded as a distinct species R. tanezumi, based on differentiation in karyotype and morphology.