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Tantilla gracilis

Baird and Girard, 1853

Flat-headed Snake

G5Secure Found in 2 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.102843
Element CodeARADB35040
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusTantilla
Other Common Names
flat-headed snake (EN) Flathead Snake (EN)
Concept Reference
Cole, C. J., and L. M. Hardy. 1981. Systematics of North American colubrid snakes related to Tantilla planiceps (Blainville). Bull. Am. Mus. Nat. Hist. 171:199-284.
Conservation Status
Review Date2005-12-15
Change Date1996-10-30
Edition Date2005-12-15
Edition AuthorsHammerson, G.
Threat ImpactMedium
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 to >300
Range Extent Comments
The range extends from eastern Kansas, Missouri, and southwestern Illinois south through Oklahoma and Arkansas to central Louisiana, Texas, and adjacent Coahuila and Tamaulipas, Mexico (Conant and Collins 1991, Ernst and Ernst 2003).
Occurrences Comments
This species is represented by a very large number of occurrences. For example, Werler and Dixon (2000) mapped more than 200 collection sites in Texas, and Trauth et al. (2004) mapped more than 100 collection sites in Arkansas. In Mexico, the species is known from only a few specimens
Threat Impact Comments
Tennant (1998) reported that nest predation by non-native fire ants has decimated populations in Texas. Werler and Dixon (2000) did not mention this threat.
Ecology & Habitat

Habitat

Habitats include rocky prairie, wooded hillsides, rocky forest edges, pine-oak uplands, oak-juniper brakes, pine woods, moist deciduous woods, thorn woodland, and grass-brushland (Dundee and Rossman 1989, Tennant 1998, Werler and Dixon 2000, Ernst and Ernst 2003, Trauth et al. 2004). This semifossorial snake often is found under rocks or logs after spring or summer rains. Eggs are laid in shallow underground hollows, under rocks (e.g., Cobb 1990), or in decaying vegetation.

Reproduction

Lays clutch of 1-4 eggs, June-July. Eggs hatch in September (Fitch 1970). May sometimes nest communally (Cobb 1990).
Terrestrial Habitats
Woodland - HardwoodWoodland - MixedShrubland/chaparralGrassland/herbaceousCropland/hedgerow
Other Nations (1)
United StatesN5
ProvinceRankNative
ArkansasS4Yes
OklahomaSNRYes
TexasS5Yes
KansasS4Yes
LouisianaS3Yes
MissouriS4Yes
IllinoisS1Yes
Threat Assessments
ThreatScopeSeverityTiming
8 - Invasive & other problematic species, genes & diseases——High (continuing)
8.1 - Invasive non-native/alien species/diseases——High (continuing)

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Roadless Areas (2)
Arkansas (1)
AreaForestAcres
Little BlakelyOuachita National Forest3,342
Missouri (1)
AreaForestAcres
Big Creek Rare II Study AreaMark Twain National Forest9,277
References (20)
  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. Cobb, V. A. 1990. Reproductive notes on the eggs and offspring of <i>Tantilla gracilis</i> (Serpentes: Colubridae), with evidence of communal nesting. Southwest. Nat. 35:222-224.
  3. Cobb, V. A. 2004. Diet and prey size of the flathead snake, <i>Tantilla gracilis</i>. Copeia 2004:397-402.
  4. Cole, C. J., and L. M. Hardy. 1981. Systematics of North American colubrid snakes related to Tantilla planiceps (Blainville). Bull. Am. Mus. Nat. Hist. 171:199-284.
  5. Collins, J. T. 1982. Amphibians and reptiles in Kansas. Second edition. Univ. Kansas Mus. Nat. Hist., Pub. Ed. Ser. 8. xiii + 356 pp.
  6. 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.
  7. Collins, J. T. 1993. Amphibians and reptiles in Kansas. Third edition, revised. University of Kansas Museum of Natural History, Public Education Series No. 13. xx + 397 pp.
  8. Conant, R., and J. T. Collins. 1998. A field guide to reptiles and amphibians: eastern and central North America. Third edition, expanded. Houghton Mifflin Co., Boston, Massachusetts. 616 pp.
  9. 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
  10. 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.
  11. 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]
  12. Dundee, H. A., and D. A. Rossman. 1989. The amphibians and reptiles of Louisiana. Louisiana State University Press, Baton Rouge.
  13. Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
  14. Fitch, H. S. 1970. Reproductive cycles of lizards and snakes. Univ. Kansas Museum Natural History Miscellaneous Publication 52:1-247.
  15. Johnson, T. R. 2000. The amphibians and reptiles of Missouri. Second edition. Missouri Department of Conservation, Jefferson City. 400 pp.
  16. Phillips, C. A., R. A. Brandon, and E. O. Moll. 1999. Field guide to amphibians and reptiles of Illinois. Illinois Natural History Survey Manual 8. xv + 282 pp.
  17. Tennant, A. 1984. The Snakes of Texas. Texas Monthly Press, Austin, Texas. 561 pp.
  18. Tennant, A. 1998. A field guide to Texas snakes. Second edition. Gulf Publishing Company, Houston, Texas.
  19. Trauth, S. E., H. W. Robison, and M. V. Plummer. 2004. The amphibians and reptiles of Arkansas. University of Arkansas Press.
  20. Werler, J. E., and J. R. Dixon. 2000. Texas snakes: identification, distribution, and natural history. University of Texas Press, Austin. xv + 437 pp.