Reptiles of North Carolina
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NC Records

Sceloporus undulatus - Eastern Fence Lizard


Photo: J. Mickey
Photo: Skyla Stuckey
Adult male doing a push-up display. Photo: J.Mickey
Juvenile. Photo: J. Mickey
Taxonomy
Class: Reptilia Order: Squamata Family: Phrynosomatidae
Taxonomic Comments: The Eastern Fence Lizard is one of twenty-two species in this genus that occur in North America north of Mexico (SSAR, 2017). This genus is especially numerous in the western United States but only three are known to occur in the Southeast (see Powell et al., 2016)' the Eastern Fence Lizard is the only one that occurs in North Carolina. This species is also our sole native representative of the Phrynosomatidae, although we still appear to have a few introduced populations of the Texas Horned Lizard (Phrynosoma cornutum).
Species Comments: Sceloporus undulatus previously included a number of subspecies whose ranges were located west of the Mississippi River and some extending as far west as Rocky Mountains. Based on a molecular DNA study (Leaché and Reeder, 2002) these former subspecies have now been raised to full species status and the nominate subspecies is the sole remainder of this group still included under S. undulatus (SSAR, 2017). No separation was determined between the two subspecies previously recognized in the East, S.u.undulatus and S.u.hyacinthinus -- the form recognized by Palmer and Braswell (1995). Instead of a north-south division between those two purported forms, Leach and Reeder found what appears to be a more significant split between populations located west and east of the Appalachians, which they recommended be studied further.
Identification
Description: This species is easily recognizable in a good quality photograph. Brown-phase Anoles are similar in size and shape but have granular rather than spiny scales. They also lack the pattern of transverse banding on their dorsal surface, although they may have a pale dorsal longitudinal line.
Field Marks: This is a rough-scaled lizard that shows a range of colors from slate gray to bronze to yellow-brown. The dorsal surface is marked with darker transverse, wavy bands. Juveniles are typically darkly shaded gray. Females tend to be a lighter gray with more contrasting, darker bands that are often edged with white; males are more uniformly brown, bronze, or yellowish above with less contrasting cross-bands, which can be yellowish rather than gray. They also have iridescent blue patches on their throat and belly that are strongly edged with black. Some females can also have small patches of blue, particularly on their throats.
Morphological Features: As a member of the Spiny Lizard group, the scales of this species are dorsally keeled and possess sharp posterior projections, giving it an overall rough appearance. No other species in North Carolina has scales with these features. Females are larger in this species. Maximum head-body lengths measured in North Carolina are: 3.1" (80mm), females; 2.9" (73.6mm), males (Palmer and Braswell, 1995).
Technical Reference: Palmer and Braswell (1995)
Field Guide Descriptions: Beane et al. (2010)
Online Photos:    Google   iNaturalist   GBIF
Observation Methods: The colors and patterns of Fence Lizards blend in with the tree trunks and rocks they inhabit, making them difficult to spot. When flushed, they often climb up a tree on the side opposite of the human or other animal that caused the disturbance.
Distribution in North Carolina
Distribution Comments: Fence Lizards occur across the state, from the Blue Ridge to the Lower Coastal Plain. They are unrecorded from the barrier islands, however, and Palmer and Braswell (1995) noted that they are missing from the Tidewater region more generally despite the presence of apparently suitable habitat. One record from above 5,000' is mentioned by Palmer and Braswell (1995), but records are otherwise missing from elevations above 4,000'.
Distribution Reference: Palmer and Braswell (1995); NCMNS Herpetology Collection Database (accessed 2023-01)
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: Eastern Fence Lizards prefer dry, open woodlands composed of hardwoods and pines, particularly areas that have abundant basking sites (Palmer and Braswell, 1995). This species is semi-arboreal, perching on tree trunks, from which it makes foraging sorties. They also climb trees as the main way to escape predators. Boulders are also used, as well as fences, walls, and buildings but usually where they are located close to woodlands.
Environmental and Physiological Tolerances: In North Carolina, the upper limits of the distribution of this species in the mountains is likely to be the result of intolerance of harsh winters. They may also be flood-intolerant, which would help explain their general absence from bottomland habitats and tidewater areas subject to flooding from hurricanes.
Adaptations to Natural Disturbances: Parker (1994) noted decreases in recruitment following heavy rain events that may have affected survival of eggs. He also speculated that colder-than-normal winters can also reduce populations.
Biotic Relationships: Fence Lizards feed primarily on small arthropods. As observed in gut content studies done in Georgia (Hamilton and Pollack, 1961) and Mississippi (Parker, 1994), ants make up the majority of their diet, with Lepidopteran larvae, beetles, and spiders also commonly consumed. Parker recorded the remains of at least one Ground Skink in the gut contents he examined. Fence Lizards, in turn, are preyed upon by several species of snakes, predatory birds, and mammalian carnivores.
Life History and Autecology
Breeding and Courtship: Individuals become mature in the year following their hatching. Mating takes place in the home ranges of the females, where males interact agonistically to gain access to the females (Haenel et al., 2003a). Males use displays to advertise their prowess, performing push-up that display the bright blue patches on their undersides. Dominant males develop a reddish-yellow color dorsally; subordinate males have dark brown dorsal surfaces instead (Haenel et al., 2003a).
Reproductive Mode: Mating takes place in the spring and egg laying in late spring and early summer, with females digging their nests in the soil (Palmer and Braswell, 1995). Clutch sizes observed in North Carolina range from 6 to 16mm (see Palmer and Braswell for details).
Terrestrial Life History: Fence Lizards occupy permanent home ranges but males, at least, do not defend them as territories (Haenel et al., 2003a); they do, however, defend breeding sites from incursions by other males. Home ranges of the males are larger than those of females and overlap extensively with both those of other males and females (Haenel at al., 2003b). Females, on the other hand, occupy smaller ranges that largely do not overlap with those of other females. Female ranges center on basking and foraging structures, such as logs or rocks, whereas males center their ranges on clusters of the female ranges (Haenel et al., 2003b).
General Ecology
Adverse Environmental Impacts
Habitat Loss: Vast areas of the state that once supported the forests occupied by this species have been converted to agriculture or urbanized areas and no longer support this species.
Habitat Fragmentation: As in our other terrestrial reptiles, major highways probably represent impassible barriers to the movements of this species.
Effects of Introduced Species/Induced Increases of Native Species: Red Imported Fire Ants were shown by Thawley and Langkilde (2016) to prey on the nests of Sceloporus undulatus. Juvenile Fence Lizards are also susceptible to poisoning by eating fire ants (Venable and Langkilde, 2019)
Status in North Carolina
NHP State Rank: S5
Global Rank: G5
Status Comments: Eastern Fence Lizards occupy habitats that are still common and widespread across the state, although it appears to be puzzlingly absent from some areas. Overall, its populations appear to be secure.
Stewardship: In a study done in the Green River Game Land in North Carolina, Greenburg and Waldrop (2008) found that Fence Lizards and other lizard species benefited from both mechanical fuel reduction and burning of forest vegetation, probably by opening up the canopy and increasing insolation at the ground level.

Photo Gallery for Sceloporus undulatus - Eastern Fence Lizard

67 photos are available. Only the most recent 30 are shown.

Recorded by: J. Mickey
Stokes Co.
Comment: 		Recorded by: K. Williams
Surry Co.
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Recorded by: J. Mickey
Wilkes Co.
Comment: 		Recorded by: J. Mickey
Wilkes Co.
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Recorded by: J. Perry
Stokes Co.
Comment: 		Recorded by: J. Mickey
Wilkes Co.
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Recorded by: J. Mickey
Alleghany Co.
Comment: 		Recorded by: Travis McLain
Gaston Co.
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Recorded by: Travis McLain
Montgomery Co.
Comment: 		Recorded by: Erich Hofmann
Bladen Co.
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Recorded by: Mark Shields
Alexander Co.
Comment: 		Recorded by: J. Mickey
Stokes Co.
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Recorded by: Travis McLain
Stokes Co.
Comment: 		Recorded by: J. Mickey
Wilkes Co.
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Recorded by: Travis McLain
Stanly Co.
Comment: 		Recorded by: J.Buie
Stokes Co.
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Recorded by: J. Mickey
Surry Co.
Comment: 		Recorded by: J. Mickey
Wilkes Co.
Comment: STMO - Along horse trail loop in rotting stump. @ -81.057250, 36.378041
Recorded by: J. Mickey
Surry Co.
Comment: 		Recorded by: J. Mickey
Surry Co.
Comment:
Recorded by: J. Mickey
Surry Co.
Comment: 		Recorded by: Erich Hofmann and Kayla Weinfurther
Bladen Co.
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Recorded by: Travis McLain
Anson Co.
Comment: 		Recorded by: J. Mickey
Surry Co.
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Recorded by: J. Mickey
Wilkes Co.
Comment: 		Recorded by: J. Mickey
Surry Co.
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Recorded by: J. Mickey
Wilkes Co.
Comment: 		Recorded by: J. Mickey
Surry Co.
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Recorded by: Travis McLain
Cabarrus Co.
Comment: 		Recorded by: J. Mickey
Wilkes Co.
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