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Agkistrodon piscivorus

(Lacepède, 1789)

Northern Cottonmouth

G5Secure Found in 22 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
MediumThreat Impact
Northern Cottonmouth (Agkistrodon piscivorus). Photo by Dominic, CC BY 4.0, via iNaturalist.
Dominic, CC BY 4.0
Northern Cottonmouth (Agkistrodon piscivorus). Photo by Etienne Falquet, CC0 1.0, via iNaturalist.
Etienne Falquet, CC0 1.0
Identity
Unique IDELEMENT_GLOBAL.2.960784
Element CodeARADE01030
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicendemic to a single nation
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyViperidae
GenusAgkistrodon
Other Common Names
cottonmouth (EN)
Concept Reference
Burbrink, F. T., and T. J. Guiher. 2014 [2015]. Considering gene flow when using coalescent methods to delimit lineages of North American pitvipers of the genus Agkistrodon. Zoological Journal of the Linnean Society 173(2):505-526.
Taxonomic Comments
Using multi-locus nuclear data, Burbrink and Guiher (2015) partially confirmed previous mitochondrial hypotheses (Guiher and Burbrink 2008) that the two North American species (A. contortrix and A. piscivorus) each consist of multiple species-level taxa. Subspecies are not recognized; this species comprises the previously recognized subspecies A. p. piscivorus and A. p. leucostoma; Agkistrodon piscivorus conanti has been elevated to species status.
Conservation Status
Review Date2006-09-08
Change Date1997-02-26
Edition Date2006-09-08
Edition AuthorsHammerson, G., J. C. Mitchell, and C. A. Pague
Threat ImpactMedium
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 to >300
Rank Reasons
Widespread occurrence in the southeastern United States, though spotty at range periphery; still common in many areas.
Range Extent Comments
The range extends from southeastern Virginia (near junction of Appomattox and James rivers) to southern Florida, west to central Texas, Oklahoma, Arkansas, Missouri, and southeastern Kansas (Triplett, 1991, Herpetol. Rev. 22:135), and north in the middle Mississippi River drainage to southern Illinois (Mitchell 1994, Phillips et al. 1999, Werler and Dixon 2000, Minton 2001, Campbell and Lamar 2004).
Occurrences Comments
This species is represented by a large number of occurences (subpopulations) (e.g., see dot maps of collection sites in Dundee and Rossman 1989, Palmer and Braswell 1995, Werler and Dixon 2000, Campbell and Lamar 2004, and Trauth et al. 2004).
Threat Impact Comments
From a range-wide perspective, no major threats are known. Locally, threats include wetland drainage for agriculture, residential and commercial development, and forestry, and disturbance and direct killing by humans (Blem and Blem 1995).
Ecology & Habitat

Habitat

This snake occurs in a wide range of aquatic and wetland habitats: swamps, sloughs, delta bayous, bayheads, ponds and streams in pine flatwoods, pine-palmetto forest, offshore keys, marshes, river bottoms, lowland floodplains, tidal stream courses, dune and beach areas, clear upland brooks, drainage ditches in some southern cities, brackish waters, and sometimes salt marshes (Ernst and Ernst 2003, Campbell and Lamar 2004). Cottonmouths may aggregate under waterbird rookeries. Hibernation sites include rocky wooded hillsides, in crayfish burrows, under rotting stumps or other cover, or in burrows of mammals (e.g., beavers, muskrats) or tortoises.

Ecology

May be locally abundant; e.g., formerly occurred at a density of over 700/ha at a pond in Kentucky (Barbour, cited by Ernst 1992). In South Carolina swamp areas and Carolina bays, concentrations of a dozen or more may occasionally are found in summer when water levels are low (Gibbons and Semlitsch 1991). May hibernate communally.

Limited information indicates an average home range of about 0.1-0.2 ha, but up to at least 1.2 ha (see Ernst 1992).

Juveniles are preyed on by various predatory animals; alligators and humans are the main predators of adults (Ernst 1992).

Reproduction

Gives birth to 1-16 (mean often 5-8, higher in Virginia and North Carolina than farther south) young, mainly August-September. Evidently larger females may breed annually whereas smaller adult females are less likely to be gravid in a particular year (see Ernst 1992). Females are sexually mature in 3-4 years (Behler and King 1979, Blem and Blem 1995). In Virginia, births occurred from late August to early October; mean litter size was 7.6; 92% of mature females captured in the breeding season were reproductive (Blem and Blem 1995).
Terrestrial Habitats
Savanna
Palustrine Habitats
HERBACEOUS WETLANDSCRUB-SHRUB WETLANDFORESTED WETLANDRiparian
Other Nations (1)
United StatesN5
ProvinceRankNative
AlabamaSNRYes
MississippiS5Yes
TexasS5Yes
OklahomaSNRYes
GeorgiaS5Yes
IndianaS1Yes
KansasS1Yes
South CarolinaS5Yes
North CarolinaS5Yes
IllinoisSNRYes
VirginiaS3Yes
TennesseeS5Yes
MissouriS5Yes
LouisianaS5Yes
KentuckyS3Yes
ArkansasS5Yes
Roadless Areas (22)
Alabama (2)
AreaForestAcres
Blue MountainTalladega National Forest4,986
Cheaha BTalladega National Forest741
Arkansas (8)
AreaForestAcres
Bear MountainOuachita National Forest1,910
Blue MountainOuachita National Forest9,755
Brush HeapOuachita National Forest4,205
Clifty CanyonOzark-St. Francis National Forest1,963
Devils CanyonOzark-St. Francis National Forest1,877
East ForkOzark-St. Francis National Forest13,037
Gee CreekOzark-St. Francis National Forest7,957
PenhookOzark-St. Francis National Forest6,566
Louisiana (2)
AreaForestAcres
Cunningham Brake Research Natural AreaKisatchie National Forest1,797
Saline Bayou W & S River CorridorKisatchie National Forest5,355
North Carolina (5)
AreaForestAcres
Catfish Lake NorthCroatan National Forest11,299
Catfish Lake South - ACroatan National Forest217
Catfish Lake South - BCroatan National Forest172
Pond Pine BCroatan National Forest2,961
Sheep Ridge AdditionCroatan National Forest5,808
Oklahoma (1)
AreaForestAcres
Beech CreekOuachita National Forest8,303
South Carolina (2)
AreaForestAcres
Hellhole ExtFrancis Marion National Forest891
Wambaw ExtFrancis Marion National Forest527
Texas (2)
AreaForestAcres
Little Lake CreekNational Forests in Texas596
Winters BayouNational Forests in Texas730
References (38)
  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. Barbour, R. W. 1971. Amphibians and reptiles of Kentucky. Univ. Press of Kentucky, Lexington. x + 334 pp.
  3. 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.
  4. Blem, C. R., and L. B. Blem. 1995. The eastern cottonmouth (<i>Agkistrodon piscivorus</i>) at the northern edge of its range. Journal of Herpetology 29:391-398.
  5. Burbrink, F. T., and T. J. Guiher. 2014 [2015]. Considering gene flow when using coalescent methods to delimit lineages of North American pitvipers of the genus <i>Agkistrodon</i>. Zoological Journal of the Linnean Society 173(2):505-526.
  6. Burkett, R.D. 1966. Natural history of cottonmouth moccasin, Agkistrodon piscivorus (Reptilia). 57 pp.
  7. Campbell, J. A., and D. H. Whitmore, Jr. 1989. A comparison of the skin keratin biochemistry in vipers with comments on its systematic value. Herpetologica 45:242-249.
  8. Campbell, J. A., and E. D. Brodie, Jr., editors. 1992. Biology of the pit vipers. Selva, Tyler, Texas.
  9. Campbell, J. A., and W. W. Lamar. 2004. The venomous reptiles of the Western Hemisphere. 2 volumes. Cornell University Press.
  10. Chiasson, R. B., D. L. Bentley, and C. H. Lowe. 1989. Scale morphology in <i>Agkistrodon</i>, and closely related crotaline genera. Herpetologica 45:430-438.
  11. 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.
  12. Conant, R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Second Edition. Houghton Mifflin Company, Boston, Massachusetts. xvii + 429 pp.
  13. 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.
  14. 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.
  15. 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
  16. 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.
  17. 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]
  18. Dundee, H. A., and D. A. Rossman. 1989. The amphibians and reptiles of Louisiana. Louisiana State University Press, Baton Rouge.
  19. Ernst, C. H. 1992. Venomous reptiles of North America. Smithsonian Institution Press, Washington, D.C. ix + 236 pp.
  20. Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
  21. Ernst, C. H., and R. W. Barbour. 1989b. Snakes of eastern North America. George Mason Univ. Press, Fairfax, Virginia. 282 pp.
  22. Gibbons, J. W., and R. D. Semlitsch. 1991. Guide to the reptiles and amphibians of the Savannah River Site. Univ. of Georgia Press, Athens. xii + 131 pp.
  23. Gloyd, H. K., and R. Conant. 1990. Snakes of the <i>Agkistrodon </i> complex: a monographic review. Society for the Study of Amphibians and Reptiles. vi + 614 pp.
  24. Guiher, T.J. and F.T. Burbrink. 2008. Demographic and phylogeographic histories of two venomous North American snakes of the genus <i>Agkistrodon</i>. Molecular Phylogenetics and Evolution 48: 543–553.
  25. Johnson, T. R. 1987. The amphibians and reptiles of Missouri. Missouri Department of Conservation, Jefferson City. 368 pp.
  26. 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.
  27. Minton, S. A., Jr. 2001. Amphibians & reptiles of Indiana. Revised second edition. Indiana Academy of Science, Indianapolis. xiv + 404 pp.
  28. Mitchell, J. C. 1994. The reptiles of Virginia. Smithsonian Institution Press, Washington, D.C. xv + 352 pp.
  29. Mount, R. H. 1975. The reptiles and amphibians of Alabama. Auburn University Agricultural Experiment Station, Auburn, Alabama. vii + 347 pp.
  30. 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.
  31. 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.
  32. Smith, P. W. 1961. The amphibians and reptiles of Illinois. Illinois Natural History Survey 28(1):1-298.
  33. Tennant, A. 1984. The Snakes of Texas. Texas Monthly Press, Austin, Texas. 561 pp.
  34. Tennant, A. 1997. A field guide to snakes of Florida. Gulf Publishing Company, Houston, Texas. xiii + 257 pp.
  35. Tennant, A. 1998. A field guide to Texas snakes. Second edition. Gulf Publishing Company, Houston, Texas.
  36. Trauth, S. E., H. W. Robison, and M. V. Plummer. 2004. The amphibians and reptiles of Arkansas. University of Arkansas Press.
  37. Webb, R. G. 1970. Reptiles of Oklahoma. University of Oklahoma Press, Norman. 370 pp.
  38. Werler, J. E., and J. R. Dixon. 2000. Texas snakes: identification, distribution, and natural history. University of Texas Press, Austin. xv + 437 pp.