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Home/Species/ Six-lined Racerunner

Aspidoscelis sexlineatus

(Linnaeus, 1766)

Six-lined Racerunner

G5Secure Found in 11 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
LowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.102815
Element CodeARACJ02110
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicendemic to a single nation
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyTeiidae
GenusAspidoscelis
Synonyms
Aspidoscelis sexlineata(Linnaeus, 1766)Cnemidophorus sexlineatus(Linnaeus, 1766)
Other Common Names
six-lined racerunner (EN)
Concept Reference
Wright, J. W., and L. J. Vitt. 1993. Biology of whiptail lizards (genus Cnemidophorus). Oklahoma Museum of Natural History, Norman, Oklahoma.
Taxonomic Comments
Manning et al. (2005) presented evidence for hybridization between A. neomexicana and A. sexlineatus viridis, but there is no indication either that this hybridization has produced a new hybrid species or that it is leading to the fusion of the two species (Crother 2017).

Reeder et al. (2002) examined phylogenetic relationships of the whiptail lizards of the genus Cnemidophorus based on a combined analysis of mitochondrial DNA, morphology, and allozymes. They determined that Cnemidophorus in the traditional sense is paraphyletic and thus in need of nomenclatural revision. Rather than subsume all cnemidophorine species (including Kentropyx) in a single large genus (Ameiva), they proposed a split that placed the North American "Cnemidophorus" clade in the monophyletic genus Aspidoscelis; under this arrangement, South American taxa remain in the genus Cnemidophorus.
Conservation Status
Review Date2005-08-30
Change Date1996-10-29
Edition Date2009-11-06
Edition AuthorsHammerson, G.
Threat ImpactLow
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Range Extent Comments
Range extends from eastern Wyoming, South Dakota, Minnesota, Wisconsin, Indiana, Kentucky, Virgina, and Maryland south to southern Texas, the Gulf Coast, and southern Floridat (Trauth and McAllister 1996).
Occurrences Comments
This species is represented by at least several hundred occurrences or subpopulations (e.g., see map in Trauth and McAllister 1996).
Threat Impact Comments
No major threats have been identified. Locally, some populations have declined or disappeared as a result of conversion of habitat to human uses. Historically, much habitat may have been lost with agricultural expansion.
Ecology & Habitat

Description

These lizards have a long and slender body, small granular scales on the back, and larger rectangular scales on the belly. Three pale stripes extend along each side of the back, and there is a middorsal stripe that sometimes is divided into two stripes. There are no light spots or bars in the dark fields between the stripes. In some areas, the neck and shoulders of adults often have a bright greenish wash. The scales on the undersurface of the base of the forelimb are not enlarged. Maximum size is about 10.5 inches (27 cm) in total length, 3.5 inches (8.8 cm) snout-vent length. Mature males have a pale blue belly (whitish in females). Hatchlings are 1.2-1.4 inches (31-35 mm) in snout-vent length, with a bright blue tail and light stripes that contrast sharply with the dark areas on the shoulders. Source: Hammerson (1999).

Habitat

Six-lined racerunners inhabit grassland, sandhills, sandy or gravelly banks and floodplains of streams, sparsely vegetated rocky areas at the base of mountains, woodland edges and open woods, beach dunes, and similar situations with full or partial sun exposure. They generally take shelter underground or under rocks or other objects on the ground; sometimes they escape threats by submerging in pools of water and may remained submerged by at least a few minutes. Eggs are laid in a nest dug in soft soil or sawdust pile (Mount 1975) or under logs or other sheltering objects (Barbour 1971).

Ecology

In Kansas, home range size averaged about 800-1,000 sq m, but individuals sometimes roamed outside their normal range and occasionally moved to new areas hundreds of meters away (Fitch 1958).

Reproduction

In most areas, courtship and mating occur in late spring or early summer. Reproductive females deposit 1-3 clutches of 1-6 eggs during May-August; in the north, egg laying does not begin until June. Eggs are laid in nests dug in soft soil or sawdust piles or under logs or other sheltering objects. Eggs hatch in about 2 months, mostly late July (August in the north) to September. Individuals become sexually mature after their second hibernation.
Terrestrial Habitats
Woodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparralGrassland/herbaceousSand/duneCropland/hedgerowSuburban/orchard
Palustrine Habitats
Riparian
Other Nations (1)
United StatesN5
ProvinceRankNative
ArkansasS5Yes
WisconsinS2Yes
New MexicoS4Yes
MarylandS3Yes
MichiganS1Yes
West VirginiaS1Yes
ColoradoS5Yes
TexasS5Yes
AlabamaSNRYes
GeorgiaS5Yes
North CarolinaS5Yes
IllinoisS3Yes
MinnesotaS4Yes
LouisianaS4Yes
South DakotaS2Yes
IowaS3Yes
MissouriS5Yes
WyomingS2Yes
VirginiaS5Yes
TennesseeS4Yes
OklahomaSNRYes
KentuckyS3Yes
South CarolinaS5Yes
NebraskaS5Yes
KansasS5Yes
IndianaSUYes
FloridaS4Yes
MississippiS5Yes
Threat Assessments
ThreatScopeSeverityTiming
2 - Agriculture & aquaculture——Insignificant/negligible or past
2.1 - Annual & perennial non-timber crops——Insignificant/negligible or past

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Roadless Areas (11)
Arkansas (1)
AreaForestAcres
Clifty CanyonOzark-St. Francis National Forest1,963
Florida (3)
AreaForestAcres
Alexander Springs CreekOcala National Forest2,954
Farles PrairieOcala National Forest1,901
Long BayApalachicola National Forest5,726
Louisiana (1)
AreaForestAcres
Cunningham Brake Research Natural AreaKisatchie National Forest1,797
Missouri (1)
AreaForestAcres
Big Creek Rare II Study AreaMark Twain National Forest9,277
North Carolina (4)
AreaForestAcres
Dobson KnobPisgah National Forest6,111
Linville Gorge AdditionPisgah National Forest2,809
Pond Pine BCroatan National Forest2,961
Sheep Ridge AdditionCroatan National Forest5,808
Virginia (1)
AreaForestAcres
Northern MassanuttenGeorge Washington National Forest9,444
References (24)
  1. Anderson, R. A., and H. M. Tiebout, III. 1993. The effects of timber management practices on the lizards of xeric pineland habitats: an investigation of the Florida sand pine scrub. Final report to The Nature Conservancy.
  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. Collins, J. T. 1982. Amphibians and reptiles in Kansas. Second edition. Univ. Kansas Mus. Nat. Hist., Pub. Ed. Ser. 8. xiii + 356 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. 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. Etheridge, K., L. C. Wit, and J. C. Sellers. 1983. Hibernation in the lizard <i>Cnemidophorus sexlineatus</i> (Lacertilia: Teiidae). Copeia 1983:206-214.
  11. Fitch, H.S. 1958. Natural history of the six-lined Racerunner (Cnemidophorus sexlineatus). 52 pp.
  12. Fitch, H. S. 1970. Reproductive cycles of lizards and snakes. Univ. Kansas Museum Natural History Miscellaneous Publication 52:1-247.
  13. Hammerson, G. A. 1982b. Amphibians and reptiles in Colorado. Colorado Division of Wildlife, Denver. vii + 131 pp.
  14. Manning, G. J., C. J. Cole, H. C. Dessauer, and J. M. Walker. 2005. Hybridization between parthenogenetic lizards (Aspidoscelis neomexicana) and gonochoristic lizards (Aspidoscelis sexlineata viridis) in New Mexico: ecological, morphological, cytological, and molecular context. American Museum Novitates 2005, no. 3492:1-56.
  15. Maslin, T. P., and D. M. Secoy. 1986. A checklist of the lizard genus <i>Cnemidophorus</i> (Teiidae). Univ. Colorado Mus., Contrib. in Zoology No. 1. 60 pp.
  16. Minton, S. A., Jr. 1972. Amphibians and reptiles of Indiana. Indiana Academy Science Monographs 3. v + 346 pp.
  17. Mount, R. H. 1975. The reptiles and amphibians of Alabama. Auburn University Agricultural Experiment Station, Auburn, Alabama. vii + 347 pp.
  18. Reeder, T. W., C. J. Cole, and H. C. Dessauer. 2002. Phylogenetic relationships of whiptail lizards of the genus <i>Cnemidophorus </i>(Squamata: Teiidae): a test of monophyly, reevaluation of karyotypic evolution, and review of hybrid origins. American Museum Novitates (3365):1-61.
  19. Stebbins, R. C. 1985a. A field guide to western reptiles and amphibians. Second edition. Houghton Mifflin Company, Boston, Massachusetts. xiv + 336 pp.
  20. Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.
  21. Uetz, P., P. Freed, R. Aguilar, F. Reyes, and J. Hošek (eds.). 2023. The Reptile Database. Online. Available: http://www.reptile-database.org
  22. Vogt, R. C. 1981c. Natural history of amphibians and reptiles of Wisconsin. Milwaukee Public Museum. 205 pp.
  23. Walker, J. M., et al. 1990. Hybridization between all-female <i>Cnemidophorus tesselatus</i> and gonochoristic <i>Cnemidophorus sexlineatus</i>. J. Herpetol. 24:388-396.
  24. Wright, J. W., and L. J. Vitt. 1993. Biology of whiptail lizards (genus <i>Cnemidophorus</i>). Oklahoma Museum of Natural History, Norman, Oklahoma.