Thamnophis scaliger


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Thamnophis scaliger
Species Authority: (Jan, 1863)

Assessment Information [top]

Red List Category & Criteria: Vulnerable B1ab(iii) ver 3.1
Year Published: 2007
Date Assessed: 2007-03-01
Assessor(s): Canseco-Márquez, L., Mendoza-Quijano, F. & Gustavo Quintero Díaz
Reviewer(s): Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)
Listed as Vulnerable because its extent of occurrence is less than 20,000 km², it is known from fewer than ten locations, it is severely fragmented in parts of its range, and there is continuing decline in the extent and quality of its habitat.

Geographic Range [top]

Range Description: This species is endemic to central Mexico. It is present as isolated highland populations in the Central Plateau and the volcanic belt. It has been recorded from Michoacan, Aguascalientes, State of Mexico and the Distrito Federal. It has an elevational range of 2,230 to 3,000 m asl.
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: It is an uncommon species.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: The species is associated with streams and small canyons in semi-arid dry grasslands, shrubland and oak forest. It can be found in secondary habitats including agricultural areas, such as cattle pasture. It is a viviparous species.
Systems: Terrestrial

Threats [top]

Major Threat(s): It is threatened by extensive habitat conversion to agricultural use. Populations can remain in areas with some limited habitat conversion.

Conservation Actions [top]

Conservation Actions: It is not known to occur in any protected areas. There is a need to establish protected areas for this species. Further research is needed into the ecology, natural history and population of this species.

Bibliography [top]

IUCN. 2007. 2007 IUCN Red List of Threatened Species. Available at: (Accessed: 12th September 2007).

Queiroz, A. de, Lawson, R. and Lemos-Espinal, J.A. 2002. Phylogenetic Relationships of North American Garter Snakes (Thamnophis) Based on Four Mitochondrial Genes: How Much DNA Sequence Is Enough? Molecular Phylogenetics and Evolution 22: 315-329.

Quintero-Díaz, G., Vázquez-Díaz, J. and Smith, H.M. 1999. Geographic distribution: Thamnophis scaliger. Herpetological Review 30(4): 237.

Rossman, D.A. and Gongora, G.L. 1997. Variation in the Mexican garter snake Thamnophis scalaris Cope and the taxonomic status of T. scaliger (Jan). Occasional Papers of the Museum of Natural History Sci., Lousiana State University 74: 1-14.

Rossman, D.A., Ford, N.B. and Seigel, R.A. 1996. The Garter Snakes. University of Oklahoma Press, Norman, Oklahoma and London, UK.

Citation: Canseco-Márquez, L., Mendoza-Quijano, F. & Gustavo Quintero Díaz 2007. Thamnophis scaliger. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 30 August 2015.
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