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Thamnophis cyrtopsis

(Kennicott, 1861)

Black-necked Gartersnake

G5Secure Found in 47 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.100881
Element CodeARADB36040
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusThamnophis
Other Common Names
Black-necked Garter Snake (EN) Blackneck Garter Snake (EN)
Concept Reference
Rossman, D. A., N. B. Ford, and R. A. Seigel. 1996. The garter snakes: evolution and ecology. University of Oklahoma Press, Norman. xx + 332 pp.
Taxonomic Comments
Thamnophis cyrtopsis was for many years referred to as T. eques (see Rossman et al. 1996 for a discussion of the complicated taxonomic history of T. cyrtopsis). Thamnophis cyrtopsis includes "Thamnophis vicinus," formerly regarded as a distinct species but now regarded as a localized color pattern morph of T. cyrtopsis occurring in Michoacan, Mexico (Rossman 1996).
Conservation Status
Review Date2005-12-16
Change Date1996-10-30
Edition Date2005-12-16
Edition AuthorsHammerson, G.
Threat ImpactMedium
Range Extent200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)
Number of Occurrences81 to >300
Range Extent Comments
The range extends from southern Colorado and Utah south through Arizona, New Mexico, western and central Texas, and much of Mexico to Guatemala, at elevations from near sea level to around 2,700 meters (8,700 feet) (Webb 1980, Rossman et al. 1996, Stebbins 2003). The distribution is spotty in many areas.
Occurrences Comments
This species is represented by many occurrences or subpopulations. Webb (1980) mapped over 200 collection sites across the entire range.
Threat Impact Comments
No major threats are known. In some areas, habitat has been lost or degraded as a result of urbanization, deforestation, or conversion to intensive agricultural uses. The pet trade is a potential threat to this species.
Ecology & Habitat

Habitat

This snake occurs in a wide range of habitats, from desert flats, dry grasslands, and tropical lowlands to pine-oak habitats and cloud forest in mountains; in the southwestern United States it is often in the vicinity of permanent and intermittent streams, spring seepages, and irrigation canals, usually in canyons, foothills, or mountains (Stebbins 2003). It inhabits rocky hillsides and limestone ledges, and wooded ravines and cedar brakes, in the Texas Hill Country (Tennant 1984). In Mexico, habitats include tropical barrancas, thorny scrub forest, tropical deciduous forest, and upper arid or mixed boreal-tropical cloud forest (Rossman et al. 1996). This snake wanders far from water into adjacent grassland, desert, woodland, and shrubland, but mostly it is restricted to the vicinity of consistent water sources in the arid Southwest (Jones 1990).

Reproduction

Gives birth to 3-25 young (usually less than 10), June- August.
Terrestrial Habitats
Woodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparralGrassland/herbaceousDesert
Palustrine Habitats
Riparian
Other Nations (1)
United StatesN5
ProvinceRankNative
ArizonaS4Yes
TexasS5Yes
Navajo NationSNRYes
New MexicoS5Yes
ColoradoS2Yes
UtahS3Yes
OklahomaS1Yes
Roadless Areas (47)
Arizona (29)
AreaForestAcres
Arnold MesaPrescott National Forest12,286
Black CrossTonto National Forest5,966
BoulderTonto National Forest40,359
Butterfly Roadless AreaCoronado National Forest42,296
Catalina St. Pk. Roadless AreaCoronado National Forest951
Cdo WsaCoronado National Forest1,955
CenterfireApache-Sitgreaves National Forests13,130
ChiricahuaCoronado National Forest76,876
GaliuroCoronado National Forest28,333
GoldfieldTonto National Forest15,257
Happy ValleyCoronado National Forest7,972
Hell HoleApache-Sitgreaves National Forests15,512
HellsgateTonto National Forest6,171
Lime CreekTonto National Forest42,568
Lower RinconCoronado National Forest3,278
Lower San FranciscoApache-Sitgreaves National Forests59,310
MazatzalTonto National Forest16,942
Middle Dragoon RoadlessCoronado National Forest10,543
Middle Romero WSRCoronado National Forest60
NolanApache-Sitgreaves National Forests6,780
Oracle RoadlessCoronado National Forest22,365
PinalenoCoronado National Forest130,920
Santa TeresaCoronado National Forest8,929
Sierra Ancha Wilderness ContiguousTonto National Forest7,787
TumacacoriCoronado National Forest44,594
Upper Dragoon RoadlessCoronado National Forest2,533
Upper Rincon RoadlessCoronado National Forest2,991
Upper Romero WsrCoronado National Forest150
WhetstoneCoronado National Forest20,728
New Mexico (18)
AreaForestAcres
Aspen MountainGila National Forest23,784
Brushy MountainGila National Forest7,199
Candian RiverCibola National Forest7,149
Contiguous To Black & Aldo Leopold WildernessGila National Forest111,883
Contiguous To Gila Wilderness & Primitive AreaGila National Forest79,049
Devils CreekGila National Forest89,916
Elk MountainGila National Forest6,550
Hell HoleGila National Forest19,553
Last Chance CanyonLincoln National Forest8,934
Little Dog And Pup CanyonsLincoln National Forest25,412
Lower San FranciscoGila National Forest26,460
Meadow CreekGila National Forest34,167
NolanGila National Forest13,051
Ortega PeakLincoln National Forest11,545
Peloncillo (NM)Coronado National Forest43,339
Sawyers PeakGila National Forest59,743
South Guadalupe MountainsLincoln National Forest20,930
West Face Sacramento MountainsLincoln National Forest41,176
References (19)
  1. Behler, J. L., and F. W. King. 1979. The Audubon Society field guide to North American reptiles and amphibians. Alfred A. Knopf, New York. 719 pp.
  2. Collins, J. T. 1990. Standard common and current scientific names for North American amphibians and reptiles. 3rd ed. Society for the Study of Amphibians and Reptiles. Herpetological Circular No. 19. 41 pp.
  3. Crother, B. I. (editor). 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Sixth edition. Society for the Study of Amphibians and Reptiles Herpetological Circular 37:1-84. Online with updates at: http://www.ssarherps.org/pages/comm_names/Index.php
  4. Crother, B. I. (editor). 2012. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 7th edition. SSAR Herpetological Circular 39:1-92.
  5. Crother, B. I. (editor). 2017. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 8th edition. SSAR Herpetological Circular 43:1-104. [Updates in SSAR North American Species Names Database at: https://ssarherps.org/cndb]
  6. Degenhardt, W. G., C. W. Painter, and A. H. Price. 1996. Amphibians and reptiles of New Mexico. University of New Mexico Press, Albuquerque. xix + 431 pp.
  7. Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
  8. Fitch, H. S. 1970. Reproductive cycles of lizards and snakes. Univ. Kansas Museum Natural History Miscellaneous Publication 52:1-247.
  9. Hammerson, G. A. 1982b. Amphibians and reptiles in Colorado. Colorado Division of Wildlife, Denver. vii + 131 pp.
  10. Hammerson, G. A. 1999. Amphibians and reptiles in Colorado. Second edition. University Press of Colorado, Boulder. xxvi + 484 pp.
  11. Jones, K. B. 1990. Habitat use and predatory behavior of <i>Thamnophis cyrtopsis</i> (Serpentes: Colubridae) in a seasonally variable aquatic environment. Southwest. Nat. 35:115-122.
  12. Lawson, R. 1987. Molecular studies of thamnophiine snakes: 1. The phylogeny of the genus <i>Nerodia</i>. J. Herpetology 21:140-157.
  13. Minton, S. A. 1959. Observations on amphibians and reptiles of the Big Bend region of Texas. Southwestern Naturalist 3:28-54.
  14. Rossman, D. A., N. B. Ford, and R. A. Seigel. 1996. The garter snakes: evolution and ecology. University of Oklahoma Press, Norman. xx + 332 pp.
  15. Stebbins, R. C. 1985a. A field guide to western reptiles and amphibians. Second edition. Houghton Mifflin Company, Boston, Massachusetts. xiv + 336 pp.
  16. Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.
  17. Tennant, A. 1984. The Snakes of Texas. Texas Monthly Press, Austin, Texas. 561 pp.
  18. Webb, Robert G. 1980. <i>Thamnophis cyrtopsis</i>. Catalogue of American Amphibians and Reptiles. (245):1-4.
  19. Woodin, W. H., III. 1953. Notes on some reptiles from the Huachuca area of southeastern Arizona. Bulletin of the Chicago Academy of Science 9:285-296.