Takydromus toyamai 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Lacertidae

Scientific Name: Takydromus toyamai Takeda & Ota, 1996
Common Name(s):
English Miyako Grass Lizard
Tachydromus smaragdinus Boulenger, 1917
Takydromus smaragdinus Stejneger, 1907
Taxonomic Notes:

Previously considered as belonging to the otherwise central Ryukyu species Takydromus smaragdinus Boulenger (Boulenger 1887), but turned out to be a distinct species even phylogenetically rather distant from T. smaragdinus (see Lin et al. 2002; Ota et al. 2002).

Assessment Information [top]

Red List Category & Criteria: Endangered B2ab(i,iii) ver 3.1
Year Published: 2010
Date Assessed: 2009-06-30
Assessor(s): Ota, H.
Reviewer(s): Böhm, M., Collen, B. & Ram, M. (Sampled Red List Index Coordinating Team)
Contributor(s): De Silva, R., Milligan, H.T., Wearn, O.R., Wren, S., Zamin, T., Sears, J., Wilson, P., Lewis, S., Lintott, P. & Powney, G.
Takydromus toyamai has been assessed as Endangered under criterion B2ab(iii), as it has been recorded on only two islands in the Miyako Group, southern Ryuku Archipelago, Japan (but may also be present on another four islands of this island group). This species has an extent of occurrence of just over 190 km² and is affected by habitat loss due to land development and predation by introduced weasels throughout all of its range. Recent increase of introduced peacocks in the central part of Miyakojima that prey on this lizard seems to be causing its population decline in this region. Further research into the threats should be carried out as T. toyamai has a restricted distribution and may qualify for listing in an even higher threat category in the future.

Geographic Range [top]

Range Description:This species inhabits the Miyako Island Group of the southern Ryukyu Archipelago of Japan (Takeda and Ota 1996). It is known to occur on Miyakojima and Irabujima, and is assumed to also be present on the other islands in the group, namely Shimojijima, Ikemajima, Ohgamijima, and Kurimajima (Takeda and Ota 1996).

This species represents the Miyako Group population of T. smaragdinus, a grass lizard that is distributed throughout the Okinawa and Amami island groups, and on two southern islands of the Tokara island groups of the central Ryuku Archipelago. Due to differences in scutellation and coloration, Takeda and Ota (1996) determined the Miyako population to be a separate species. A subsequent molecular study revealed that T. toyamai is phylogenetically rather distant from T.smaragdinus in reality (Lin et al. 2002, Ota  et al. 2002). It is known that T. smaragdinus inhabits Shimojijima, Ikemajima, Ohgamijima, and Kurimajima, however, as Takeda and Ota (1996) were unable to get specimens from either the field or museums from these four islands for re-examination, they were not able to confirm these to be T. toyamai. However, due to the isolation of the Miyako Group from the other three island groups, it is likely that the individuals on these four islands are also T. toyamai.

The area in which this species is distributed is approximately 190 km² and is described as severely fragmented (H. Ota pers.comm. 2010).
Countries occurrence:
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:There is no population information available for this species.
Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:This species prefers grassland with patches of shrubs, however, it is also found in broadleaf forest.

It is oviparous, with a clutch size of two eggs (Takeda and Ota 1996).

Threats [top]

Major Threat(s): This species is supposedly being impacted upon by predation from introduced weasels across the full extent of its range. Also, recently established populations of exotic peacocks in the central forested area of Miyakojima seems to be putting a substantial predation pressure upon the lizard population in this region, most likely causing its decline (Ota and Takahashi 2009). Detailed intensive studies are strongly desired to clarify the current population status of the species on both Miyakojima and Irabujima.

Conservation Actions [top]

Conservation Actions: There are no known species-specific conservation measures in place for this species. Further research into the taxonomy of this species should be carried out. Monitoring of this species population in response to the threats outlined.

Citation: Ota, H. 2010. Takydromus toyamai. The IUCN Red List of Threatened Species 2010: e.T178488A7557101. . Downloaded on 19 October 2017.
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