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:

This taxon was previously considered as belonging to the otherwise central Ryukyu species Takydromus smaragdinus (Boulenger 1887), but is now recognized to be a distinct, phylogenetically rather distant species (see Lin et al. 2002, Ota et al. 2002).

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(iii,v)+2ab(iii,v) 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.
Takydromus toyamai has been assessed as Endangered, as it has very limited distribution range (an extent of occurrence below 500 km2 and an area of occupancy of around 200 km²) only and is affected by habitat destruction due to land development and predation by introduced weasels and peacock. In addition, a sharp decline in the frequency of occurrence in recent decades suggests that this species is undergoing a continuing decline in the number of mature individuals.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is endemic to the Miyako Islands Group of the Southern Ryukyus, Japan, where it is found on Miyakojima, Irabujima, Shimojijima, Ikemajima, Ohgamijima, and Kurimajima Islands (Takenaka 2014). The combined area of the islands where this species occurs is approximately 200 km2.
Countries occurrence:
Japan (Nansei-shoto)
Additional data:
Estimated area of occupancy (AOO) - km2:203.43
Range Map:Click here to open the map viewer and explore range.

Population [top]


This lizard is uncommon. It has become difficult to find in any known locality, although there was at least one site where it had been abundant with an apparently stable population until around 2000 (Takenaka 2014). It is considered to survive as a severely fragmented population (H. Ota pers. comm. 2016).

Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes
Extreme fluctuations:UnknownPopulation severely fragmented:Yes

Habitat and Ecology [top]

Habitat and Ecology:

Takydromus toyamai inhabits sunny grasslands and bushland. It is also found on shrubs at the forest edges and in farmland. It is diurnal and active on leaves and branches. It never hibernates but becomes inactive during winter. It mainly preys on small invertebrates such as insects and spiders. Females lay two eggs per clutch at the bottom of plants or shallow underground, multiple times per year. Eggs hatch without parental care after a month, and animals reach reproductive maturity the following year (Takenaka 2014).

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

Use and Trade [top]

Use and Trade: Although it is possible that there may be illegal collection of this lizard for the international pet trade, there is no detailed information.

Threats [top]

Major Threat(s): This species is apparently being impacted by predation from introduced weasels, Mustela itatsi, across the full extent of its range. Recently established populations of exotic peacocks in the central forested area of Miyakojima seem to represent substantial additional predation pressure upon the lizard population in this region, most likely causing its severe decline (Ota and Takahashi 2008).  Land development and pesticide pollution, formerly the main threats to this species prior to the introduction of these species, are also ongoing. It is possible that this species is captured by pet-traders illegally (Takenaka 2014).

Conservation Actions [top]

Conservation Actions: This species is protected and harvest is forbidden under a local regulation in Miyakojima city. Further research into the taxonomy of this species should be carried out. Detailed intensive studies are highly desirable to clarify the current population status of the species on both Miyakojima and Irabujima.

Classifications [top]

1. Forest -> 1.6. Forest - Subtropical/Tropical Moist Lowland
suitability:Suitable season:resident 
3. Shrubland -> 3.6. Shrubland - Subtropical/Tropical Moist
suitability:Suitable season:resident 
4. Grassland -> 4.5. Grassland - Subtropical/Tropical Dry
suitability:Suitable season:resident major importance:Yes
14. Artificial/Terrestrial -> 14.1. Artificial/Terrestrial - Arable Land
suitability:Marginal season:resident 
2. Land/water management -> 2.1. Site/area management
2. Land/water management -> 2.2. Invasive/problematic species control

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Unknown
In-Place Species Management
In-Place Education
2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.4. Scale Unknown/Unrecorded
♦ timing:Ongoing ♦ scope:Unknown ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.1. Hunting & trapping terrestrial animals -> 5.1.1. Intentional use (species is the target)
♦ timing:Unknown ♦ scope:Unknown ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

8. Invasive and other problematic species, genes & diseases -> 8.1. Invasive non-native/alien species/diseases -> 8.1.2. Named species [ Pavo cristatus ]
♦ timing:Ongoing ♦ scope:Minority (<50%) ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

8. Invasive and other problematic species, genes & diseases -> 8.1. Invasive non-native/alien species/diseases -> 8.1.2. Named species [ Mustela itatsi ]
♦ timing:Ongoing ♦ scope:Whole (>90%) ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

9. Pollution -> 9.3. Agricultural & forestry effluents -> 9.3.3. Herbicides and pesticides
♦ timing:Ongoing ♦ scope:Unknown ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.1. Taxonomy
3. Monitoring -> 3.1. Population trends

Bibliography [top]

Arnold, E.N. 1997. Interrelationships and evolution of the east Asian grass lizards, Takydromus (Squamata: Lacertidae). Zoological Journal of the Linnaen Society 119: 267-296.

IUCN. 2017. The IUCN Red List of Threatened Species. Version 2017-3. Available at: (Accessed: 5 December 2017).

Lin, S.-M., Chen, C.A. and Lue, K.-Y. 2002. Molecular phylogeny and biogeography of the grass lizards genus Takydromus (Reptilia: Lacertidae) of East Asia. Molecular Phylogenetics and Evolution 22(2): 276-288.

Ota, H. and Takahashi, A. 2008. Mysterious fauna of the Miyako Islands. In: Association for the Study of Nature and Human Culture of the Miyako Islands (eds), Nature and Human Culture of the Miyako Islands, pp. 24-44. Naha.

Ota, H., Honda, M., Chen, S.-L., Hikida, T., Panha, S., Oh, H.-S. and Matsui, M. 2002. Phylogenetic relationships, taxonomy, character evolution and biogeography of the lacertid lizards of the genus Takydromus (Reptilia: Squamata): a molecular perspective. Biological Journal of the Linnean Society 76: 493-509.

Takeda, N. and Ota, H. 1996. Description of a New Species of Takydromus from the Ryukyu Archipelago, Japan, and a Taxonomic Redefinition of T. smaragdinus Boulenger 1887 (Reptilia: Lacertidae). Herpetologica 52(1): 77-88.

Takenaka, S. 2014. Miyako grass lizard. In: Ministry of Environment (ed.), Red Data Book 2014.-Threatened Wildlife of Japan -: Reptilia /Amphibia, pp. 6-7. GYOSEI Corporation, Tokyo.

Citation: Kidera, N. & Ota, H. 2017. Takydromus toyamai. The IUCN Red List of Threatened Species 2017: e.T178488A96878070. . Downloaded on 15 October 2018.
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