Sinomicrurus japonicus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Elapidae

Scientific Name: Sinomicrurus japonicus (Günther, 1868)
Common Name(s):
English Japanese Coral Snake
Callophis japonicus Günther, 1868
Hemibungarus japonicus (Günther, 1868)
Micrurus japonicus ssp. japonicus (Günther, 1868)
Taxonomic Notes: This species has three subspecies:
S. japonicus boettgeri (Fritze, 1894)
S. japonicus japonicus (Günther, 1868)
S. japonicus takarai (Ota, Ito & Lin, 1999).

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2017
Date Assessed: 2016-12-13
Assessor(s): Kidera, N. & Ota, H.
Reviewer(s): Bowles, P.
Facilitator/Compiler(s): De Silva, R., Milligan, H.T., Wearn, O.R., Wren, S., Zamin, T., Sears, J., Wilson, P., Lewis, S., Lintott, P., Powney, G.

Sinomicrurus japonicus has been assessed as Near Threatened because it has an estimated extent of occurrence approximately 22,000 km2 and may not occur as a severely fragmented population across most of its range, putting it outside the thresholds for listing in a threatened category applying criterion B. Nevertheless the species occurs at low densities, all subspecies are thought to be undergoing some degree of population decline as a result of predation by introduced species, and the subspecies S. j. takarai has undergone a severe decline across its range apparently as a result of habitat loss and the impacts of invasive species.

Previously published Red List assessments:

Geographic Range [top]

Range Description:

Sinomicrurus japonicus is endemic to Amami and Okinawa Islands, the Central Ryukyus, Japan. Three subspecies are allopatrically distributed; S. j. japonicus occurs on Amamioshima, Kakeromajima, Ukejima and Yorojima Islands of the Amami Group (Ota 2014a), S. j. boettgeri occurs on Tokunoshima Island of the Amami Group and Okinawajima, and several islets adjacent to the latter in the Okinawa Group (Ota 2014b), and S. j. takarai occurs on Kumejima, Tonakijima, Akajima, Gerumajima, Amurojima, Zamamijima and Iejima Islands, all in the Okinawa Group (Ota 2014c).

Countries occurrence:
Japan (Nansei-shoto)
Additional data:
Estimated area of occupancy (AOO) - km2:2433.87
Range Map:Click here to open the map viewer and explore range.

Population [top]


Of the three subspecies, Sinomicrurus japonicus takarai is considered to be undergoing a critical decline. In Akajima, Gerumajima and Zamamijima, this subspecies is now hardly found, although there is little detailed information of population status. There have been no recorded observations since the 1980s, which suggests that local extinctions may already have occurred on one or more of these islands (Ota 2014c). The other two subspecies are uncommon and population density is not high (Ota 2014a). 

Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes
Population severely fragmented:Unknown

Habitat and Ecology [top]

Habitat and Ecology:

The Japanese Coral Snake inhabits natural broadleaf evergreen forest, recovered secondary forests, and vegetated limestone where the environment is consistently humid. This species preys on snakes and lizards. It is likely that females lay a clutch of several eggs in June (Ota 2014a,b,c).

Continuing decline in area, extent and/or quality of habitat:Yes

Use and Trade [top]

Use and Trade: There is no known use of or trade in this species.

Threats [top]

Major Threat(s):

Sinomicrurus japonicus takarai is threatened by habitat loss and degradation resulting from deforestation and land development in Kumejima, and by predation from introduced Japanese weasels on Akajima, Gerumajima and Zamamijima (Ota 2014c). For S. j. boettgeri and S. j. japonicus, it is considered that habitat quality is in decline due to deforestation and predation by introduced Small Indian Mongoose (Ota 2014a,b).

Conservation Actions [top]

Conservation Actions: There are no species-specific conservation measures. Further research into the population, habitat status, and threats to this species should be carried out, and population monitoring is recommended. The identification and establishment of protected areas would benefit this species restricted to the Ryukyu Islands.

Citation: Kidera, N. & Ota, H. 2017. Sinomicrurus japonicus. The IUCN Red List of Threatened Species 2017: e.T177491A96877688. . Downloaded on 16 October 2018.
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