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Callosciurus erythraeus subspp.

Basic information
Scientific name Callosciurus erythraeus subspp.

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Common names Formosan squirrel
Higher taxon Sciuridae, Rodentia, Mammalia
Natural range Taiwan, southern continental China, Indochina and Malay Peninsula, northeastern India.
Habitat Broad leaved evergreen forest. Human habitat.
Invasion information
Range in Japan Kanagawa Pref. (SE), Shizuoka Pref. (Izu Peninsula and Hamamtsu), Gifu Pref.(Mt. Kinkazan), Osaka Pref.(Osaka Castle Park), Wakayama Pref.(Wakayama Castle Park and Tomogashima Is.), Oita Pref. (Takashima Is.), Nagasaki Pref. (Iki and Fukue Is.), Kumamoto Pref. (Uto Peninsula), and Izuoshima Is. (Izu Islands), Tokyo Metro (Akiruno city), Saitama Pref. (Iruma city) Range in Japan
Origin From Taiwan to Izuoshima. From Izuoshima to Enoshima and Tomogahima of Kanagawa and Wakayama Prefs. According to DNA analyses, Izu Peninsula and Fukuejima Is. populations were close to Taiwanese populations, whereas Hamamatsu population may be from continental China (or possibly hybrid with anothe congener). 
Date The first record of escape was in 1935, in Izuoshima Is., Izu Islands. In other region, Enoshima, Kanagawa Pref.: 1951; Tomogashima Is., Wakayama Pref.: 1954; Kinkazan, Gifu Pref.: 1955; Takashima Is., Oita Pref.: 1959; Osaka, Himeji, Hyogo, and Hamamatsu: 1970s; Izu Peninsula, Fukuejima Is., and Iki: 1980s; Uto Peninsula, Kumamoto Pref.: 2008; Akiruno, Tokyo Metro. and Iruma, Saitama Pref.: 2011.
Route Deliberate: Intentional release or escape from zoo
Impact Actually: Damage on human house, electric cable, etc. Damage on vegetation. Damage on agriculture.
Potentially: Competitive with native sciurid animals.
Native organism(s) affected: Sciurid mammals, birds, insects, trees, vegetation, and crops.
Regulation in Japan Import, transport and keeping are prohibited by the Invasive Alien Species Act.
Introduced range in other countries Argentina, France, Belgium, Italy, Netherlands
Reference Notes
  • Abe (ed) (1994) A Guide to Mammals of Japan. Tokai Univ. Press, Hatano (in Jpn)
  • Asakawa (2005) The host-parasite relationships between alien terrestrial vertebrates and their parasitic helminths in Japan. Jpn J Conserv Ecol. 10(2), 173-183 (in Jpn with Englis abst)
  • DECO (ed) (2006) Dictionary of Alien Species. Tokyo-Shoseki, Tokyo (in Jpn)
  • Ecol Soc Jpn (ed) (2002) Handbook of Alien Species in Japan. Chijinshokan, Tokyo (in Jpn)
  • Izawa et al. (eds) (1996) The Encyclopedia of Animals in Japan 2 Mammals II. Heibonsha, Tokyo (in Jpn)
  • JWRC (ed) (2008) A Photographic Guide to the Invasive Alien Species in Japan. Heibonsha, Tokyo (in Jpn)
  • Ohdachi et al. (eds) (2009) The Wild Mammals of Japan. Shokado, Kyoto.
  • Yamada et al. (eds) (2011) Invasive Alien Mammals in japan: Biology of Control Strategy and Conservation. Univ. Tokyo Press (in Jpn)
  • Yasuda (2010) Feral population of the Pallas’s squirrel Callosciurus erythraeus in the Uto Peninsula, Kumamoto Prefecture, Kyushu Island, Japan. Risu-to-Musasabi. 24, 1-6 (in Jpn)
  • etc.
All the species of Callosciurus (except C. erythraeus) are designated as Uncategorized Alien Species by the Invasive Alien Species Act (import and keeping in Japan require 6 months investigation for risk assessment).