Ophisaurus ventralisEastern Glass Lizard

Geographic Range

Eastern glass lizards (Ophisaurus ventralis) are native to North America along the Atlantic and Gulf Coastal Plains. Their geographic range includes Florida, the majority of Georgia and South Carolina, coastal North Carolina, and southeastern Virginia. Their range extends westward along the Gulf coast as far as eastern Louisiana. Eastern glass lizards have also been observed as far south as the Cayman Islands, although it is unclear whether they arrived naturally or were introduced by humans. (Ashton and Sawyer Ashton, 1985; Beane, et al., 2010; Brunt and Davies, 1994; Mitchell and Reay, 1999)

Habitat

Eastern glass lizards are terrestrial and can be found in both wet and dry areas. Habitats include pine flatwoods, wet grasslands, and areas near beaches. They are commonly found in wet meadows or near sand dunes, often hiding under debris. (Behler and King, 1979; Burnie and Wilson, 2005; Conant and Collins, 1998)

Physical Description

Eastern glass lizards are tan-colored and 15 to 20 cm long at birth. As they mature, eastern glass lizards develop dark green dorsal coloration with numerous black lines that run laterally from their heads to their tails. They have yellow ventral coloration, and usually have white markings on their necks and their dorsal sides. However, they display no stripes on the medial portion of their backs or ventral to their lateral grooves. Males and females differ in color, but are otherwise similar in appearance. Females are greener than males, whereas males are yellowish green, often with broader color stripes and gold or brown speckles along their bodies. This sexual dimorphism becomes more apparent as individuals reach sexual maturity. Eastern glass lizards can be differentiated from other glass lizard species by the absence of a dorsomedial stripe.

Eastern glass lizards lack forelegs and hindlegs. They are the longest known lizards in North America. They range in length from 45 to 108 cm. The largest individuals measure around 30.48 cm in snout-vent length (SVL). Their tails comprise the majority of their total body length and are usually more than twice their SVL, or around 70 cm in the largest individuals. As adults, eastern glass lizards weigh 300 to 600 g.

Eastern glass lizards have grooves that run laterally from head to tail along both sides of their bodies. These lateral grooves allow their bodies to expand when breathing, during pregnancy, or after eating. Although eastern glass lizards resemble snakes in that they lack legs, they have eyelids and external ear openings similar to other lizard species. (Badger, 2006; Behler and King, 1979; Burnie and Wilson, 2005; Capula, 1990; Conant and Collins, 1998; Oliver, 1955)

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • Range mass
    300 to 600 g
    10.57 to 21.15 oz
  • Range length
    45 to 108 cm
    17.72 to 42.52 in
  • Average length
    95 cm
    37.40 in

Development

There is limited information regarding early development of eastern glass lizards. Upon hatching, eastern glass lizards are tan-colored and are usually about 15 to 20 cm long. (Conant and Collins, 1998)

Reproduction

There is limited information regarding the mating system of eastern glass lizards. They mate in spring and lay eggs in late summer or early fall. Females lay clutches of 5 to 17 eggs, which generally hatch in about 2 months. (Schwartz and Henderson, 1991; Sunquist, 2007)

Eastern glass lizards reach sexual maturity at around 2 years of age. They generally mate once a year, starting in spring. Females lay clutches of 5 to 17 eggs in shallow nests, often under logs or clumps of grass. Females remain in nests with their eggs while they incubate, which takes 50 to 65 days. Eggs hatch in late summer or early fall and hatchlings are completely independent at birth. (Badger, 2006; Beane, et al., 2010; Sunquist, 2007; Trauth, 1984)

  • Breeding interval
    Eastern glass lizards breed once a year.
  • Breeding season
    Eastern glass lizards breed from spring to early fall.
  • Range number of offspring
    5 to 17
  • Range gestation period
    50 to 65 days
  • Average time to independence
    0 days
  • Average age at sexual or reproductive maturity (female)
    2 years
  • Average age at sexual or reproductive maturity (male)
    2 years

Eastern glass lizards exhibit little parental investment in their young. Males exhibit no investment beyond the act of mating. Females lay their eggs in covered areas and remain with their eggs until they hatch. Females may flee if they are startled during incubation, but return later and use their snouts to regroup eggs if they were disturbed. Females exhibit no parental investment after their eggs hatch. (Badger, 2006; Beane, et al., 2010)

Lifespan/Longevity

There is limited information regarding the longevity of eastern glass lizards in the wild. Their lifespan in captivity ranges from 4 to 15 years. (Slavens and Slavens, 2003)

  • Typical lifespan
    Status: captivity
    4 to 15 years

Behavior

Eastern glass lizards are crepuscular and generally hunt for their food at dawn, dusk, or after it rains. They spend most of their time burrowing through loose soil in search for insects. In winter, eastern glass lizards brumate in burrows below the frost line.

Eastern glass lizards are mostly solitary and only interact with conspecifics during their breeding season. They have small home ranges and do not move far from the area where they hatch, but they are active foragers that frequently move throughout their home range to find food. In the midmorning or early evening, eastern glass lizards often bask on rocks, paved roads, or other solar-exposed areas. (Badger, 2006; Sunquist, 2007)

Home Range

There is limited information on the home range size of eastern glass lizards. However, their behavior and home range size may be similar to a closely related species, slender glass lizards (Ophisaurus attenuates). Slender glass lizard males generally have small home ranges around 0.0044 km^2. Slender glass lizard females and juveniles have smaller home ranges around 0.0014 km^2. (Fitch, 1989)

Communication and Perception

There is limited information regarding the methods by which eastern glass lizards communicate. They are mainly solitary and likely rely on visual and olfactory cues to perceive their environment and detect prey. They have forked tongues and well-developed Jacobson's organs, which help them detect the direction and source of chemicals from their environment. (Capula, 1990)

  • Communication Channels
  • visual

Food Habits

Eastern glass lizards are carnivores that mainly hunt for food around dawn, dusk, or after it rains. They mainly eat insects, spiders, worms, slugs, and snails. However, they will also opportunistically eat bird eggs or small vertebrates, such as snakes and lizards. Eastern glass lizards are active predators that rely on visual and olfactory cues to locate prey. They also use their tongues to touch prey and determine if they are dead or easy-to-catch. (Burnie and Wilson, 2005; Capula, 1990)

  • Animal Foods
  • reptiles
  • insects
  • terrestrial non-insect arthropods
  • mollusks
  • terrestrial worms

Predation

Eastern glass lizards are most threatened by humans (Homo sapiens). Natural predators of eastern glass lizards include hawks, snakes, and carnivorous mammals.

If caught, eastern glass lizards will thrash about and try to bite. They also exhibit autotomy, meaning they can intentionally drop their tails, which often break into several pieces after falling off. Their tails also continue to move about after they fall off, which can distract predators and allow eastern glass lizards to escape. (Attenborough, 2008; Beane, et al., 2010; Terwilliger and Tate, 1995)

  • Known Predators

Ecosystem Roles

Eastern glass lizards serve as hosts for black-legged ticks (Ixodes scapularis), which often attach to eastern glass lizards along their lateral grooves. Larval black-legged ticks are commonly found on eastern glass lizards from April to October, with peaks from May to June. (Durden, et al., 2002)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Eastern glass lizards have no known positive economic impacts on humans.

Economic Importance for Humans: Negative

Eastern glass lizards have no known negative economic impacts on humans.

Conservation Status

Eastern glass lizards are listed as a species of least concern according to the IUCN Red List. They are listed as part of the Virginia Wildlife Action Plan in Tier II. This means that eastern glass lizards in Virginia may be at risk for extinction in the future and they require state-level conservation efforts. Populations of eastern glass lizards are low in Virginia, but no action plans are currently in place. Eastern glass lizards are not listed on any other national or international conservation lists. The only major threat known to affect eastern glass lizards is anthropogenic land development, which replaces and fragments their habitat. (Hammerson, 2007; "Virginia's comprehensive wildlife conservation strategy", 2005)

Contributors

Ashley Graham (author), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Emily Clark (editor), Radford University, Cari Mcgregor (editor), Radford University, Jacob Vaught (editor), Radford University, Galen Burrell (editor), Special Projects.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

crepuscular

active at dawn and dusk

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

female parental care

parental care is carried out by females

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

References

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Mitchell, J., K. Reay. 1999. Atlas of Amphibians and Reptiles in Virginia. Richmond, VA: Virginia Department of Game and Inland Fisheries.

Mount, R. 1975. The Reptiles and Amphibians of Alabama. Tuscaloosa, AL: University Alabama Press.

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Schwartz, A., R. Henderson. 1991. Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, Florida: University of Florida Press.

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Sunquist, F. 2007. Florida (Travellers' Wildlife Guides). Northampton, MA: Interlink Books.

Terwilliger, K., J. Tate. 1995. A Guide to Endangered and Threatened Species in Virginia. Blacksburg, VA: The McDonald & Woodward Publishing.

Trauth, S. 1984. Seasonal incidence and reproduction in the western slender glass lizard, Ophisaurus attenuatus (Reptilia, Anguidae), in Arkansas. The Southwestern Naturalist, 29/3: 271-275.