Achalinus werneri 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Xenodermatidae

Scientific Name: Achalinus werneri Van Denburgh, 1912
Common Name(s):
English Amami Takachiho Snake
Identification information:

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2017
Date Assessed: 2016-12-03
Assessor(s): Kidera, N. & Ota, H.
Reviewer(s): Bowles, P.

Listed as Near Threatened because it is unlikely to be declining fast enough to qualify for listing in a more threatened category, however, its extent of occurrence is below 15,000 km2, it is thought to occur as a severely fragmented population and there is likely to be some pressure on its population from predation by introduced species as well as some degree of ongoing habitat loss. This species' ecological tolerances are however somewhat broader than previously recognized and it can persist in degraded habitats close to inland water, and declines in the extent and quality of its habitat are therefore not considered sufficiently severe to warrant listing as threatened under criterion B1ab(iii).

Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is endemic to the islands of Amamiohshima, Kakeromajima, Tokunoshima, Okinawajima and Tokashikijima, all part of the Central Ryukus in Japan (Ota 2014).
Countries occurrence:
Japan (Nansei-shoto)
Additional data:
Estimated area of occupancy (AOO) - km2:2265.64
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This is a common species though is not found at high densities. There is little quantitative information on the population status of this species. It is thought to occur as a severely fragmented population following fragmentation of natural forest, and its natural inability to disperse through open habitats that confines it to areas near water sources away from forest.
Current Population Trend:Unknown
Additional data:
Population severely fragmented:Yes

Habitat and Ecology [top]

Habitat and Ecology:This snake tends to hide under fallen leaves and inhabits forest floors. It is also found in open environments, including grassland and farmland, but is restricted in these habitats to areas near inland water because this snake is extremely susceptible to desiccation and is intolerant of high temperatures. It preys on earthworms. A clutch size of 3-8 eggs has been recorded (Ota 2014).

Use and Trade [top]

Use and Trade: There is no information on any use of or trade in this species.

Threats [top]

Major Threat(s): Considering this species' low mobility and inability to disperse through dry, open areas between habitat patches, habitat fragmentation that leads to extinction of local populations, including the construction of concrete roads and ditches, is considered a major threat. Predation by introduced Small Indian Mongoose is also considered a threat (Ota 2014).

Conservation Actions [top]

Conservation Actions:

Its distribution range includes national parks in Okinawajima and Kerama Islands, although there is clearly a need for improved protection of forest habitats in these islands.

Citation: Kidera, N. & Ota, H. 2017. Achalinus werneri. The IUCN Red List of Threatened Species 2017: e.T161A96877297. . Downloaded on 24 September 2018.
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