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Opheodrys vernalis

(Harlan, 1827)

Smooth Greensnake

G5Secure Found in 44 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.103123
Element CodeARADB47010
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusOpheodrys
Synonyms
Liochlorophis vernalis(Harlan, 1827)
Other Common Names
Couleuvre verte (FR) smooth greensnake (EN) Smooth Green Snake (EN)
Concept Reference
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.
Taxonomic Comments
Oldham and Smith (1991) demonstrated several significant categorical differences between Opheodrys aestivus and O. vernalis, indicative of a long history of divergent evolution; they assigned the latter species to a new genus (Liochlorophis), leaving aestivus as the only member of the genus Opheodrys. Crother et al. (2000) and Crother (2008, 2012) maintained vernalis in the genus Opheodrys, based on (1) unpublished genetic data indicating a sister-taxa relationship between vernalis and aestivus and (2) their preference not to recognize monotypic sister genera.

There has been some disagreement as to whether subspecies (vernalis, blanchardi) should be recognized (cf. Collins 1990, Smith et al. 1991, Grobman 1992). Grobman (1992) named a new subspecies (borealis) from Nova Scotia and New Brunswick, based on the relatively low ventral scale count.
Conservation Status
Rank MethodExpertise without calculation
Review Date2016-02-02
Change Date1996-10-30
Edition Date2005-12-09
Edition AuthorsHammerson, G.
Threat ImpactMedium
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Wide, discontinuous range in eastern and centtral North America; globally secure due primarily to extensive range and many extant occurrences; often apparently uncommon, locally common in some areas; information on populations is scant.
Range Extent Comments
The range extends from Nova Scotia westward across southern Canada to southeastern Saskatchewan, south and west to northern New Jersey, western Maryland, Virginia, West Virginia, southern Ohio, northwestern Indiana, Illinois, Missouri, Nebraska, New Mexico, Chihuahua (Mexico), and Utah, and highly disjunctly to southeastern Texas; the distribution is highly discontinuous throughout the western half of the range (Conant and Collins 1991, Grobman 1992, Walley 2003).
Occurrences Comments
This species is represented by a very large number of occurrences or subpopulations (Walley 2003).
Threat Impact Comments
No major threats have been identified. Local populations are threatened by habitat loss and degradation resulting from human activities and successional changes, but in general the species is not very threatened.
Ecology & Habitat

Description

A small-medium, slender, bright green snake with smooth dorsal scales (15 rows at mid-body), and a white or yellowish venter; each nostril is centered in a single scale; anal scale is divided; in some regions, occasional individuals are tan, and in Texas the color may be light brown with an olive wash instead of green; young are dark olive gray above, hatchlings are gray to brown above; adults turn blue or gray after death; total length usually 30-51 cm, up to 61 cm; hatchlings are about 8-17 cm long (Stebbins 1985, Conant and Collins 1991).

Diagnostic Characteristics

Differs from COLUBER CONSTRICTOR in smaller size, in having the nostril centered in a single scale rather than placed between two scales, and in having a single anterior temporal scale on each side rather than two. Differs from OPHEODRYS AESTIVUS in having smooth rather than keeled dorsal scales. Differs from SENTICOLIS TRIASPIS (green rat snake) in having fewer dorsal scale rows (15 at mid-body vs. 25 or more) and in lacking keels on any of the dorsal scales.

Habitat

Habitats include meadows, grassy marshes, moist grassy fields at forest edges, mountain shrublands, stream borders, bogs, open moist woodland, abandoned farmland, and vacant lots. This snake has been found hibernating in abandoned ant mounds.

Eggs are laid under rotting wood, underground, or under rocks.

Ecology

May aggregate in hibernacula; groups of between 100-150 have been found in Manitoba and Minnesota.

Reproduction

Eggs are laid usually during the first three weeks of August in northern Michigan, mainly late June to late July in the Chicago area, Illinois. Clutch size is 3-18 (generally 4-9). Eggs hatch in a few to about 30 days, early August to early September in northern Michigan, mostly early to mid-August in Chicago. Probably sexually mature in about two years. Copulation has been recorded in August in Ontario. Sometimes nests communally (Fitch 1970; Herp. Rev. 20:84).
Terrestrial Habitats
Woodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparralSavannaGrassland/herbaceousOld fieldSuburban/orchard
Palustrine Habitats
HERBACEOUS WETLANDSCRUB-SHRUB WETLANDBog/fenRiparian
Other Nations (2)
United StatesN5
ProvinceRankNative
ColoradoS4Yes
MontanaS2Yes
New HampshireS3Yes
MarylandS4Yes
West VirginiaS4Yes
MichiganS3Yes
VermontS3Yes
MinnesotaS4Yes
ConnecticutS3Yes
WyomingS2Yes
TexasSXYes
IllinoisS3Yes
VirginiaS3Yes
OhioS1Yes
New MexicoS3Yes
IndianaS2Yes
IowaS3Yes
Rhode IslandS5Yes
North DakotaSNRYes
WisconsinS4Yes
South DakotaS3Yes
MissouriSXYes
PennsylvaniaS4Yes
New JerseyS3Yes
KansasS1Yes
MassachusettsS5Yes
UtahS3Yes
MaineS5Yes
New YorkS4Yes
NebraskaS1Yes
CanadaN5
ProvinceRankNative
OntarioS4Yes
Nova ScotiaS4Yes
ManitobaS3Yes
Prince Edward IslandS2Yes
New BrunswickS4Yes
SaskatchewanS4Yes
QuebecS4Yes
Roadless Areas (44)
Colorado (4)
AreaForestAcres
Dome PeakRoutt NF35,716
HermosaSan Juan NF148,103
Long ParkRoutt NF42,100
Red TableWhite River NF39,122
New Mexico (15)
AreaForestAcres
Black CanyonSanta Fe National Forest1,922
Capitan MountainsLincoln National Forest14,069
Columbine - Hondo Wilderness Study AreaCarson National Forest43,739
Comales CanyonCarson National Forest4,389
Holy GhostSanta Fe National Forest2,352
Jefferies CanyonLincoln National Forest8,934
Juan de Gabaldon GrantSanta Fe National Forest8,023
Little TesuqueSanta Fe National Forest815
Ortega PeakLincoln National Forest11,545
Pacheco CanyonSanta Fe National Forest1,012
PecosCarson National Forest13,436
San Pedro ParksSanta Fe National Forest5,824
Tesuque CreekSanta Fe National Forest810
Thompson PeakSanta Fe National Forest33,001
West Face Sacramento MountainsLincoln National Forest41,176
Pennsylvania (1)
AreaForestAcres
Allegheny FrontAllegheny National Forest7,430
Utah (10)
AreaForestAcres
418012Uinta National Forest25,758
418013Uinta National Forest14,643
418015Uinta National Forest17,289
418016Uinta National Forest35,240
418024Uinta National Forest51,699
418025Uinta National Forest32,698
418040Uinta National Forest1,702
LakesWasatch-Cache National Forest121,967
Mt. AireWasatch-Cache National Forest9,681
Mt. OlympusWasatch-Cache National Forest9,982
Virginia (4)
AreaForestAcres
Brushy MountainJefferson National Forest4,168
Laurel ForkGeorge Washington National Forest9,967
Little RiverGeorge Washington National Forest27,292
Southern MassanuttenGeorge Washington National Forest11,985
West Virginia (7)
AreaForestAcres
Canaan LoopMonongahela National Forest7,867
Cranberry AdditionMonongahela National Forest11,123
Cranberry Glades Botanical AreaMonongahela National Forest785
Dolly Sods Roaring PlainMonongahela National Forest13,392
Dry River (WV)George Washington National Forest7,331
North Mountain HopevilleMonongahela National Forest6,525
Seneca CreekMonongahela National Forest22,287
Wyoming (3)
AreaForestAcres
Labonte CanyonMedicine Bow-Routt National Forest16,281
Rock CreekMedicine Bow-Routt National Forest18,874
Snowy RangeMedicine Bow-Routt National Forest29,660
References (31)
  1. Baxter, G. T. and M. D. Stone. 1985. Amphibians and reptiles of Wyoming. Second edition. Wyoming Game and Fish Department, Cheyenne. 137 pp.
  2. 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.
  3. Brodman, R., S. Cortwright, and A. Resetar. 2002. Historical changes of reptiles and amphibians of northwest Indiana fish and wildlife properties. American Midland Naturalist 147:135-144.
  4. 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.
  5. 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.
  6. 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.
  7. 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
  8. 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.
  9. 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]
  10. 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.
  11. 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.
  12. DeGraaf, R. M., and D. D. Rudis. 1983a. Amphibians and reptiles of New England. Habitats and natural history. Univ. Massachusetts Press. vii + 83 pp.
  13. Ernst, C. H., and R. W. Barbour. 1989b. Snakes of eastern North America. George Mason Univ. Press, Fairfax, Virginia. 282 pp.
  14. Figg, D. E. 1991. Missouri Department of Conservation Annual Nongame and Endangered Species Report July 1990 - June 1991. ii + 35 pp.
  15. Fitch, H. S. 1970. Reproductive cycles of lizards and snakes. Univ. Kansas Museum Natural History Miscellaneous Publication 52:1-247.
  16. Green, N. B., and T. K. Pauley. 1987. Amphibians and reptiles in West Virginia. University of Pittsburgh Press, Pittsburgh, Pennsylvania. xi + 241 pp.
  17. Grobman, A. 1992b. On races, clines, and common names in <i>Opheodrys</i>. Herpetol. Rev. 23:14-15.
  18. Grobman, A. B. 1992a. Metamerism in the snake <i>Opheodrys vernalis</i>, with a description of a new subspecies. J. Herpetol. 26:175-186.
  19. Hammerson, G. A. 1982b. Amphibians and reptiles in Colorado. Colorado Division of Wildlife, Denver. vii + 131 pp.
  20. Hammerson, G. A. 1999. Amphibians and reptiles in Colorado. Second edition. University Press of Colorado, Boulder. xxvi + 484 pp.
  21. Hulse, A. C., C. J. McCoy, and E. Censky. 2001. Amphibians and reptiles of Pennsylvania and the Northeast. Comstock Publishing Associates, Cornell University Press, Ithaca. 419 pp.
  22. Johnson, T. R. 2000. The amphibians and reptiles of Missouri. Second edition. Missouri Department of Conservation, Jefferson City. 400 pp.
  23. Minton, S. A., Jr. 1972. Amphibians and reptiles of Indiana. Indiana Academy Science Monographs 3. v + 346 pp.
  24. Minton, S. A., Jr. 2001. Amphibians & reptiles of Indiana. Revised second edition. Indiana Academy of Science, Indianapolis. xiv + 404 pp.
  25. Oldham, J. C., and H. M. Smith. 1991. The generic status of the smooth green snake, <i>Opheodrys vernalis</i>. Bull. Maryland Herp. Soc. 27(4):201-215.
  26. 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.
  27. Smith, H. M., G. A. Hammerson, J. J. Roth, and D. Chizar. 1991. Distributional addenda for the smooth green snake (<i>Opheodrys vernalis</i>) in western Colorado, and the status of its subspecies. Bull. Maryland Herp. Soc. 27(2):99-106.
  28. Stebbins, R. C. 1985a. A field guide to western reptiles and amphibians. Second edition. Houghton Mifflin Company, Boston, Massachusetts. xiv + 336 pp.
  29. Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.
  30. Vogt, R. C. 1981c. Natural history of amphibians and reptiles of Wisconsin. Milwaukee Public Museum. 205 pp.
  31. Walley, H. D. 2003. <i>Liochlorophis, L. vernalis</i>. Catalogue of American Amphibians and Reptiles 776:1-13.