Roadless Areas
Home/Species/ Southern Hog-nosed Snake

Heterodon simus

(Linnaeus, 1766)

Southern Hog-nosed Snake

G2Imperiled (G2G3) Found in 11 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
VulnerableIUCN
Very high - highThreat Impact
Southern hognose snake (Heterodon simus). Photo by U.S. Fish & Wildlife Service, Public Domain (U.S. Government Work), via ECOS.
U.S. Fish & Wildlife Service, https://www.usa.gov/government-works
Identity
Unique IDELEMENT_GLOBAL.2.105330
Element CodeARADB17030
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNVulnerable
Endemicendemic to a single nation
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusHeterodon
Other Common Names
southern hog-nosed snake (EN) Southern Hognose Snake (EN)
Concept Reference
Pyron, R. A., F. T. Burbrink, and J. J. Wiens. 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 29:131.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-08-27
Change Date2025-08-27
Edition Date2025-08-27
Edition AuthorsHammerson, G., T. M. Mann, and L. Glass-Godwin (2006); rev. R. L. Gundy (2025)
Threat ImpactVery high - high
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences21 - 80
Rank Reasons
This species is patchily distributed in the Coastal Plain of the southeastern United States. The population has declined by at least 50%, is likely extirpated from Mississippi and Alabama, and has suffered range contractions and local extirpations. It is threatened by habitat loss and habitat degradation due to conversion to agriculture, livestock pasture, and pine plantation, as well as being depredated by red imported fire ants (Solenopsis invicta).
Range Extent Comments
This snake occurs on the Coastal Plain of the southeastern United States from eastern North Carolina south to central peninsular Florida and west to the western Florida Panhandle (Palmer and Braswell 1995, Tennant 1997, Ernst and Ernst 2003, Powell et al. 2016, Krysko et al. 2019). It is now very rare (or possibly extirpated) in the western part of the range in Mississippi and Alabama. Using Global Biodiversity Information Facility (GBIF) (2025) records from 2000-2025, range extent is estimated to be 355,863 km² (RARECAT 2025).

The historical range extended farther south to Lake Okeechobee, Florida and farther west to southeast Mississippi (Palmer and Braswell 1995, Tennant 1997, Ernst and Ernst 2003, Powell et al. 2016, Krysko et al. 2019, USFWS 2019)
Occurrences Comments
Applying a 10 km separation distance to GBIF (2025) records, 66 occurrences are estimated (RARECAT 2025).
Threat Impact Comments
Loss and fragmentation of sandhill habitat due to conversion to agriculture and development is a major threat (Jackson and Printiss 2000, Hipes et al. 2001, Meegan 2002). Habitat also becomes degraded due to conversion to pine plantation and pasture. Range-wide declines in recent decades are generally attributed to predation of eggs and hatchlings by red imported fire ants (Solenopsis invicta) (Tuberville et al. 2000). Road mortality is a serious threat. In Hernando County, Florida, all 39 individuals of this species found during road cruising surveys were dead on the road (Enge and Wood 2003). In North Carolina, 643 of 764 individuals detected were dead on the road (Beane et al. 2014). Collection for the pet trade is another ongoing threat (Enge and Wood 2003, Kelley 2011).
Ecology & Habitat

Description

A stocky, dark-blotched snake with a sharply upturned snout that is keeled above; belly unpatterned or mottled with grayish brown; dorsal scales keeled; anal divided; length usually 36-51 cm (up to 61 cm) (Conant and Collins 1991).

Diagnostic Characteristics

Differs from the eastern hognose snake (H. platirhinos) in that the underside of the tail is not conspicuously paler than the belly (Conant and Collins 1991).

Habitat

This snake inhabits open, xeric habitats with well-drained, sandy or sandy-loam soils such as sand ridges, stabilized coastal sand dunes, pine flatwoods, mixed oak-pine woodlands and forests, scrub oak woods, and oak hammocks; also old fields and river floodplains (Ashton and Ashton 1981, Palmer and Braswell 1995, Tennant 1997, Ernst and Ernst 2003). This snake spends considerable time burrowed in the soil.

Reproduction

Clutches of 6-13 eggs have been reported (Beane et al. 2021). Based on Heterodon nasicus, females probably mature at 2-3 years, and some individuals likely live well into their second decade. Hence generation length may be 5-10 years. One failed nest was documented as being 25 cm below the surface and 61 cm (horizontally) from the burrow entrance (Beane et al. 2021).
Terrestrial Habitats
Woodland - HardwoodWoodland - ConiferWoodland - MixedSavannaGrassland/herbaceousOld fieldSand/dune
Palustrine Habitats
Riparian
Other Nations (1)
United StatesN2
ProvinceRankNative
AlabamaSHYes
North CarolinaS1Yes
GeorgiaS1Yes
MississippiSHYes
South CarolinaS1Yes
FloridaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
1.1 - Housing & urban areasSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
2 - Agriculture & aquacultureLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
2.1 - Annual & perennial non-timber cropsLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
2.2 - Wood & pulp plantationsLarge (31-70%)Moderate - slightHigh (continuing)
4 - Transportation & service corridorsRestricted (11-30%)Serious - moderateHigh (continuing)
4.1 - Roads & railroadsRestricted (11-30%)Serious - moderateHigh (continuing)
5 - Biological resource useRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
5.1 - Hunting & collecting terrestrial animalsRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesPervasive - largeSerious - moderateHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesPervasive - largeSerious - moderateHigh (continuing)

—

Roadless Areas (11)
Florida (9)
AreaForestAcres
Alexander Springs CreekOcala National Forest2,954
Clear LakeApalachicola National Forest5,592
Farles PrairieOcala National Forest1,901
Gum BayApalachicola National Forest11,645
Impassable BayOsceola National Forest2,789
Long BayApalachicola National Forest5,726
Natural Area WsaOsceola National Forest2,543
PinhookOsceola National Forest15,405
SavannahApalachicola National Forest1,927
South Carolina (2)
AreaForestAcres
Hellhole ExtFrancis Marion National Forest891
Wambaw ExtFrancis Marion National Forest527
References (37)
  1. Ashton, R. E., Jr., and P. S. Ashton. 1981. Handbook of reptiles and amphibians of Florida. Part One: The Snakes. Windward Publishing Company, Miami, Florida. 176 pp.
  2. Beane, J. C., M. D. Martin, D. C. Smith, and S. J. Horton. 2021. <i>Heterodon simus</i> (southern hog-nosed snake). Reproduction and Nesting. Herpetological Review 52(2): 424-425.
  3. Beane, J. C., S. P. Graham, T. J. Thorp, and L. T. Pusser. 2014. Natural history of the southern hognose snake (<i>Heterodon simus</i>) in North Carolina, USA. Copeia 1: 168-175.
  4. 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.
  5. 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.
  6. Conant, R. and J. T. Collins. 1991. A field guide to reptiles and amphibians: eastern and central North America. Third edition. Houghton Mifflin Co., Boston, Massachusetts. 450 pp.
  7. 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.
  8. Crawford, B. A., J. C. Maerz, and C. T. Moore. 2020. Expert-informed habitat suitability analysis for at-risk species assessment and conservation planning. Journal of Fish and Wildlife Management 11(1): 130-150; e1944-687x. doi: 10.3996/092019-JFWM-075
  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. Edgren, Richard A. 1955. The natural history of the hog- nosed snakes, genus <i>Heterodon</i>: a review. Herpetologica 11:105-117.
  13. Enge, K. M., and K. N. Wood. 2002. A pedestrian road survey of an upland snake community in Florida. Southeastern Naturalist 1:365-380.
  14. Enge, K. M., and K. N. Wood. 2003. A pedestrian road survey of the southern hognose snake (<i>Heterodon simus</i>) in Hernando County, Florida. Florida Scientist 66:189-203.
  15. Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
  16. Ernst, C. H., and R. W. Barbour. 1989b. Snakes of eastern North America. George Mason Univ. Press, Fairfax, Virginia. 282 pp.
  17. Gibbons, J. W., and 10 others. 2000. The global decline of reptiles, dàvu amphibians. BioScience 50:653-666.
  18. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  19. Hipes, Dan, D.J. Jackson, K. Nesmith, D. Printiss and K. Brandt. 2001. Field guide to the rare animals of Florida. Florida Natural Areas Inventory, Tallahassee, Florida.
  20. Jackson, D. R., and D. Printiss. 2000. Status of habitat at known localities of the southern hognose snake in Florida. Report to the U.S. Fish and Wildlife Service. Tallahassee: Florida Natural Areas Inventory.
  21. Kelley, L. G. 2011. The embededness of hognose snakes (<i>Heterodon</i> spp.) in the wildlife pet trade and the relevance of assemblage geographies for reptile conservation. M.S. thesis. Florida State University, Tallahassee. 76 pp.
  22. Krysko, K. L., K. M. Enge, and P. E. Moler. 2019. Amphibians and Reptiles of Florida. University of Florida Press, Gainesville, Florida, USA, 706 pp.
  23. Martof, B. S., W. M. Palmer, J. R. Bailey, and J. R. Harrison, III. 1980. Amphibians and reptiles of the Carolinas and Virginia. University of North Carolina Press, Chapel Hill, North Carolina. 264 pp.
  24. Meegan, R. P. 2002. A road cruise survey for the southern hognose snake (Heterodon simus) in the Munson Sandhills of the Apalachicola National Forest. Final Report Submitted to the US Fish and Wildlife Service.
  25. Meylan, P. A. 1985. <i>Heterodon simus</i>. Cat. Am. Amph. Rep. 375.1-375.2.
  26. Mount, R. H. 1975. The reptiles and amphibians of Alabama. Auburn University Agricultural Experiment Station, Auburn, Alabama. vii + 347 pp.
  27. Palmer, W. M., and A. L. Braswell. 1995. Reptiles of North Carolina. North Carolina State Museum of Natural Sciences, University of North Carolina Press, Chapel Hill, North Carolina.
  28. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  29. Powell, R., R. Conant, and J. T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, fourth edition. Houghton Mifflin Harcourt, Boston and New York. 512 pp.
  30. Pyron, R. A., F. T. Burbrink, and J. J. Wiens. 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 29:131.
  31. Ryberg, W. A., D. K. Walkup, T. J. Hibbitts, W. Pittman, V. H. Porter, B. C. Bowers, C. M. Fielder, P. Brown, R. R. Lopez, J. R. Preston, J. T. Johnson, and B. W. Hagedorn. 2021. Effective camera trap snake surveys at a rarely accessible longleaf pine savanna. Herpetological Review 52(4): 719–724.
  32. Stevenson, D. J., E. M. Schlimm, K. M. Stohlgren, and J. Hepinstall-Cymerman. 2014. 2013–2014 Georgia status surveys for the Florida pine snake (<i>Pituophis melanoleucus mugitus</i>) and the southern hognose snake (<i>Heterodon simus</i>). 14 pp.
  33. Tennant, A. 1997. A field guide to snakes of Florida. Gulf Publishing Company, Houston, Texas. xiii + 257 pp.
  34. Tuberville, T. D., J. R. Bodie, J. B. Jensen, L. LaClaire, and J. W. Gibbons. 2000. Apparent decline of the southern hog-nosed snake, <i>Heterodon simus</i>. Journal of the Elisha Mitchell Scientific Society 116:19-40.
  35. U.S. Fish and Wildlife Service. 2019. Species status assessment report for the southern hognose snake (<i>Heterodon simus</i>), Version 1.1. April 2019. Atlanta, GA.
  36. U.S. Fish and Wildlife Service (USFWS). 2019. Twelve Species Not Warranted for Listing as Endangered or Threatened Species. Notice of findings. Federal Register 84(194): 53336-53343.
  37. U.S. Fish and Wildlife Service (USFWS). 2025. Endangered and Threatened Wildlife and Plants; Threatened Species Status With Section 4(d) Rule for Southern Hognose Snake. Proposed rule. Federal Register 90(166):42151-42178.