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Heterodon nasicus

Baird and Girard, 1852

Western Hog-nosed Snake

G5Secure Found in 3 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
Identity
Unique IDELEMENT_GLOBAL.2.1371987
Element CodeARADB17040
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusHeterodon
COSEWICSC
Concept Reference
Nicholson, K. E. (ed.). 2025. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding. Ninth Edition. Society for the Study of Amphibians and Reptiles. 87pp. Online database available at: https://cnah.org/SSARnames.aspx
Taxonomic Comments
This concept of Heterodon nasicus follows the Society for the Study of Amphibians and Reptiles (SSAR) (Nicholson 2025) in recognizing the Western Hog-nosed Snake, H. nasicus, and two subspecies, H. n. gloydi (Dusty Hog-nosed Snake) and H. n. nasicus (Plains Hog-nosed Snake) pending genetic evaluation of H. nasicus. A third subspecies, H. n. kennerlyi, was elevated to species status, H. kennerlyi, following Smith et al. (2003). Further taxonomic revision is warranted to determine whether "gloydi" is distinct from the nominate subspecies.
Conservation Status
Rank MethodLegacy Rank calculation - Excel v2.0 (2010 rank factors)
Review Date2006-08-31
Change Date1996-10-30
Edition Date2013-07-11
Edition AuthorsHammerson, G.
Range Extent200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Large range in the plains of central North America; common in many areas.
Range Extent Comments
Range extends from Alberta, Manitoba, and Saskatchewan, Canada, southward through the Great Plains region of central North America to New Mexico and Texas, and disjunctly eastward to southeastern Minnesota, Illinois, southeastern Missouri, and Oklahoma (Smith et al. 2003).
Occurrences Comments
This species is represented by a large number of occurrences (subpopulations) and locations (as defined by IUCN).
Threat Impact Comments
Conversion of prairie habitat to agricultural use has caused local declines.
Ecology & Habitat

Habitat

Habitat consists of areas with sandy or gravelly soils, including prairies, sandhills, wide valleys, river floodplains, bajadas, semiagricultural areas (but not intensively cultivated land), and margins of irrigation ditches (Degenhardt et al. 1996, Hammerson 1999, Werler and Dixon 2000, Stebbins 2003). Periods of inactivity are spent burrowed in the soil or in existing burrows. Eggs are laid in nests a few inches below the ground surface (Platt 1969).

Ecology

Population density estimated at about 4-6/ha in Kansas pasture, about half this in ungrazed area; distance between successive captures of individual snakes averaged 277 and 785 ft in two areas (Platt 1969).

Reproduction

Lays clutch of 3-23 eggs, May-August depending on locality (mainly June-July). Females may oviposit in alternate years. Sexually mature in second year (Platt 1969).
Terrestrial Habitats
Grassland/herbaceousSand/duneCropland/hedgerow
Palustrine Habitats
Riparian
Other Nations (2)
CanadaN3
ProvinceRankNative
AlbertaSNRYes
SaskatchewanSNRYes
ManitobaSNRYes
United StatesNNR
ProvinceRankNative
ColoradoSNRYes
MontanaSNRYes
WyomingSNRYes
Navajo NationSNRYes
KansasSNRYes
New MexicoS5Yes
North DakotaSNRYes
South DakotaSNRYes
MissouriSNRYes
NebraskaSNRYes
MinnesotaS3Yes
OklahomaSNRYes
TexasSNRYes
IowaSNRYes
IllinoisSNRYes
Threat Assessments
ThreatScopeSeverityTiming
2 - Agriculture & aquaculture——High (continuing)
2.1 - Annual & perennial non-timber crops——High (continuing)

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Roadless Areas (3)
New Mexico (1)
AreaForestAcres
Candian RiverCibola National Forest7,149
North Dakota (2)
AreaForestAcres
SheyenneDakota Prairie Grasslands14,537
VenloDakota Prairie Grasslands5,317
References (16)
  1. 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.
  2. 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]
  3. Crother, B. I., J. Boundy, J. A. Campbell, K. de Queiroz, D. R. Frost, R. Highton, J. B. Iverson, P. A. Meylan, T. W. Reeder, M. E. Seidel, J. W. Sites, Jr., T. W. Taggart, S. G. Tilley, and D. B. Wake. 2000 [2001]. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Society for the Study of Amphibians and Reptiles, Herpetological Circular No. 29. 82 pp.
  4. Crother, B. I., J. Boundy, J. A. Campbell, K. de Quieroz, D. Frost, D. M. Green, R. Highton, J. B. Iverson, R. W. McDiarmid, P. A. Meylan, T. W. Reeder, M. E. Seidel, J. W. Sites, Jr., S. G. Tilley, and D. B. Wake. 2003. Scientific and standard English names of amphibians and reptiles of North America north of Mexico: update. Herpetological Review 34:198-203.
  5. 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.
  6. Dixon, J. R., and J. E. Werler. 2005. Texas Snakes: A Field Guide. University of Texas Press, Austin, Texas. xvii + 364 pp.
  7. Hammerson, G. A. 1999. Amphibians and reptiles in Colorado. Second edition. University Press of Colorado, Boulder. xxvi + 484 pp.
  8. Iverson, J. B. 1990. Nesting and parental care in the mud turtle, <i>Kinosternon flavescens</i>. Can. J. Zool. 68:230-233.
  9. Nicholson, K. E. (ed.). 2025. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding. Ninth Edition. Society for the Study of Amphibians and Reptiles. 87pp. Online database available at: https://cnah.org/SSARnames.aspx
  10. Platt, D. R. 1969. Natural history of the hognose snakes Heterodon platyrhinos and Heterodon nasicus. Univ. Kansas Pub. Mus. Nat. Hist. 18:253-420.
  11. Smith, H. M., D. Chiszar, C. M. Eckerman, and H. D. Walley. 2003. The taxonomic status of the Mexican hognose snake <i>Heterodon kennerlyi </i>Kennicott (1860). Journal of Kansas Herpetology (5):17-20.
  12. Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.
  13. Walley, H. D., and C. M. Eckerman. 1999. <i>Heterodon nasicus</i>. Catalogue of American Amphibians and Reptiles. (698):1-10.
  14. Werler, J. E., and J. R. Dixon. 2000. Texas snakes: identification, distribution, and natural history. University of Texas Press, Austin. xv + 437 pp.
  15. Werler, J. E., and J. R. Dixon. 2010 Texas snakes: identification, distribution, and natural history. University of Texas Press, Austin, Texas. 519 pp.
  16. Wright, A. H. and A. A. Wright. 1957. Handbook of snakes of the United States and Canada. 2 Volumes. Comstock Publishing Associates, Ithaca, New York. 1105 pp.