The Rough Green Snake (Opheodrys aestivus) is a slender, green, semi-arboreal snake of the southeastern United States and northeastern Mexico (Behler and King 1979; Conant and Collins 1991).
Opheodrys aestivus, commonly known as the rough green snake, is found widely throughout the southeastern United States. It is found frequently as far north as southern New Jersey and can be found along the East Coast into the Florida Keys. The western range stretches to central Oklahoma, Texas, and into northern Mexico.
Biogeographic Regions: nearctic (Native )
- Mitchell, J. 1994. The Reptiles of Virginia. Washington and London: Smithsonian Institution Press.
- Gray, B. 2005. The Serpent's Cast - A Guide to the Identification of Shed Skins from Snakes of the Northeast and Mid-Atlantic States. Lansing, Michigan: ECO Herpetological Publishing & Distribution.
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)) The range extends from southern New Jersey to southern Florida, west to eastern Kansas, central Oklahoma, and central Texas, north to the southern portions of the southern Great Lakes states, south into northeastern Mexico (Nuevo Leon, Tamaulipas) (Walley and Plummer 2000).
Distribution: SE USA (Texas, Oklahoma, E Kansas, Missouri, Arkansas, Louisiana, Mississippi, S Illinois, S Indiana, S Ohio, Kentucky, Tennessee, Alabama, Georgia, Florida, South Carolina, North Carolina, Virginia, West Virginia, Maryland, Delaware, New Jersey, extreme S Pennsylvania), E Mexico
The Rough Green Snake is found from southern New Jersey to the Florida Keys; west to southeastern Kansas and Texas; and south in Mexico to Tampico, with an isolated population in Coahuila (Conant and Collins 1991).
Rough green snakes are small and thin. The dorsal and lateral surfaces are a uniform green, the underbelly, chin and labial scales range from yellowish-green to cream. Males and females have no differences in color or pattern, but females are larger in length and mass, while males have a longer tail length. Juvenile rough green snakes look like smaller adults, except they are lighter in color. Since these snakes are diurnal and tend not to avoid the heat of the day, their peritoneum is black and dense. This is believed to be an adaptation that acts as an ultraviolet radiation shield, keeping these snakes from becoming too hot. Females range from 11 to 54 g in mass, with an average of 26.7 g, males are from 9 to 27 g, with an average of 16.3 g. Average lengths are 947 mm in females and 892 mm in males.
Range mass: female: 11 male: 9 to female: 54 male: 27 g.
Average mass: female: 26.7 male: 16.3 g.
Average length: female: 947 male: 892 mm.
Other Physical Features: heterothermic
Sexual Dimorphism: sexes alike; female larger
- Plummer, M. 1993. Thermal Ecology of Arboreal Green Snakes (Opheodrys aestivus). Journal of Herpetology, Vol. 27, No. 3: 254-260.
The Rough Green Snake is 56 to 81 cm long (record 116 cm). It is a slender snake, plain light green above and plain white, yellow, or pale greenish below. (After death, the bright green coloration quickly fades to blue, a point to keep in mind if encountering a dull blue road-killed snake.) The scales (in 17 rows, Behler and King 1979) are keeled and the anal plate is divided. Young are grayish green and 17 to 23 cm long at hatching. (Conant and Collins 1991)
Length: 116 cm
In the United States, the distribution of the Rough Green Snake is largely non-overlapping with the distinctly more northern distribution of the very similar Smooth Green Snake (Opheodrys vernalis). The Rough Green Snake is more slender, grows to a much greater length, and has keeled scales (Smooth Green Snake scales are smooth, as are those of the greenish Mexican Racer, Coluber constrictor oaxaca). In terms of habit, the Rough Green Snake is more arboreal and the Smooth Green Snake more terrestrial. (Conant and Collins 1991).
Rough green snakes are typically found on forest edges near ponds or lakes. Although they are arboreal snakes, they forage in dense vegetation along pond and lake shorelines during the day. Their nights are spent coiled in the branches of trees. Rough green snakes choose perches based on distance from shorelines, height in branches, and thickness of the branch. Rough green snakes are most commonly found in deciduous trees, shrubs, hedgerows, and fields.
Habitat Regions: temperate ; terrestrial
Other Habitat Features: riparian
- Plummer, M. 1981. Habitat Utilization, Diet and Movements of a Temperate Arboreal Snake (Opheodrys aestivus). Journal of Herpetology, Vol. 15, No. 4: 425-432.
- Plummer, M. 1997. Population Ecology of Green Snakes (Opheodrys aestivus) Revisited. Herpetological Monographs, Vol. 11: 102-123.
Habitat and Ecology
Eggs are laid under objects in damp areas (Ashton and Ashton 1981), in rotting logs (Goldsmith 1984), or in tree hollows. It may nest communally. In Arkansas, gravid females moved five to 75 m (average 36 m) terrestrially away from the lake shore and oviposited in small chambers within the hollowed interiors of small living trees, 25 to 300 cm above ground; individuals may return to a specific tree each year (Plummer 1989, 1990).
Comments: This snake typically inhabits dense vegetation (vines, shrubs, trees) near water; often at forest edges or in fairly open forests; also overgrown pasture, tallgrass prairie, thickets, barrier islands; open marsh and spoil banks in Louisiana; pine-oak, mesic hardwood hammocks, and occasionally mangrove swamps in Florida (see Walley and Plummer 2000). It is mostly arboreal but less so in spring and fall. In Arkansas, it avoids basking (Plummer 1993). It occupies vegetation above ground at night in warmer months; underground in cold weather.
Eggs are laid under objects in damp areas (Ashton and Ashton 1981), in rotting logs (Goldsmith 1984), or in tree hollows. May nest communally. In Arkansas, gravid females moved 5-75 m (average 36 m) terrestrially away from lake shore and oviposited in small chambers within the hollowed interiors of small living trees, 25-300 cm above ground; individuals may return to specific tree each year (Plummer 1989, 1990).
The Rough Green Snake is sometimes almost semi-aquatic, often occuring in the dense overgrowth along streams or lakes and freely entering shallow water (Conant and Collins 1991). It may be found from sea level to 1,500 m (Behler and King 1979).
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Rough green snakes are insectivores, consuming crickets, grasshoppers, other insects, and spiders (Mitchell, 1994). They exclusively use their extraordinary vision to hunt live prey. Even a slight movement of a leg or antennae is sufficient to draw the attention of these snakes to the location of their prey (Goldsmith, 1986). According to Goldsmith (1986), during the initial phase of their approach, these snakes use fast and irregular movements, but they slow down as they further approach their prey. When rough green snakes are about 3 cm from prey, they assume spring-like curves with their body, followed by a straightening of the body, allowing the snake to propel its head toward the prey, striking either at the head or thorax. Rough green snakes sometimes raise their head above the substrate immediately upon striking in order to get prey away from anything that may aid their escape. Prey is worked further into the mouth and swallowed by movements of the jaw. Prey is usually swallowed head first.
Animal Foods: insects; terrestrial non-insect arthropods
Primary Diet: carnivore (Insectivore )
- Goldsmith, S. 1986. Feeding Behavior of an Arboreal, Insectivorous Snake (Opheodrys aestivus) (Colubridae). The Southwestern Naturalist, Vol. 31, No. 2: 246-249.
Comments: Eats mostly insects (especially caterpillars, grasshoppers, crickets) and spiders.
The bulk of the Rough Green Snake's diet consists of crickets, grasshoppers, caterpillars, and spiders (Conant and Collins 1991).
Rough green snakes are a source of prey for larger snakes, birds, and other small predators. There are a few known parasites that affect rough green snakes. They are infected occasionally with Cryptosporidium species, which affects the gastrointestinal tract, causing epithelial necrosis.
- Cryptosporidium species
- Brower, A., M. Cranfield. 2001. Cryptosporidium sp.-Associated Enteritis without Gastritis in Rough Green Snakes. Journal of Zoo and Wildlife Medicine, Vol. 32, No. 1: 101-105.
Many animals prey up on these snakes, including larger snakes, birds, domestic cats, and even some spiders (Plummer, 1990; Mitchell, 1994). Their only defense mechanism is camouflage.
- loggerhead shrikes (Lanius ludovicianus)
- hawks (Buteo species)
- domestic cats (Felis catus)
- bluejays (Cyanocitta cristata)
- kingsnakes (Lampropeltis getulus)
- racers (Coluber constrictor)
Anti-predator Adaptations: cryptic
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: This species is represented by a very large number of occurrences or subpopulations (more than 100) (see map in Walley and Plummer 2000).
100,000 to >1,000,000 individuals
Comments: Total adult population size is unknown but probably is greater than 100,000.
The best information derives from Plummer's studies in Arkansas. Average distance between recapture sites was about 28 m (Plummer 1997). Home range averaged 67 m of shoreline and differed in location between years by about 50 m (Plummer 1997). Population density was about 430/ha within 5 m of shoreline (Plummer 1985); maximum density was 800/ha at another site (Plummer 1997). First year survivorship was 21-22%; few individuals lived longer than six years (Plummer 1997). Snakes were active over a wide range of body temperatures (Plummer 1993).
Life History and Behavior
Rough green snakes use their tongue to sense chemical cues. They also have keen eyesight, allowing them to easily spot movement of prey. Mating behaviors involve tactile and visual cues.
Communication Channels: chemical
Perception Channels: visual ; tactile ; vibrations ; chemical
- Cooper, W. 2007. Elevated tongue-flicking rate to cricket surface chemicals by the arthropodivorous rough green snake Opheodrys aestivus. AMPHIBIA-REPTILIA, Volume: 28 Issue: 3: 413-417.
The Rough Green Snake is an excellent climber, often foraging amid vines and shrubs, its green body blending in with the surrounding vegetation (Conant and Collins 1991). It is active during the day (Behler and King 1979).
Comments: Active from about April to November in north (Collins 1982, Minton 1972), April to December in Texas (Tennant 1984). Essenially diurnal but sometimes active just after dark in hottest summer weather (Tennant 1984).
When compared to other snakes, Opheodrys aestivus embryos are well-developed upon egg laying. This allows for a short incubation period outside of the female, thus shortening the span for predators to eat the defenseless eggs. These eggs usually range from 21.4 to 33.6 mm long, 9.3 to 11.1 mm wide, and 1.2 to 2.4 g. Upon hatching, their length averages 128 to 132 mm and weigh 1.1 g (Mitchell, 1994). Most growth occurs in the first year of life. Females grow at a faster pace and reach larger sizes than males. According to Plummer (1985), the growth of rough green snakes follows the Von Bertalanffy model, which allows any size snake to be aged relatively accurately. However, this model is more accurate for younger snakes; error is positively correlated with age.
- Plummer, M. 1985. Growth and Maturity in Green Snakes (Opheodrys aestivus). Herpetoligica, 41: 28-33.
Survival rates are not well known for juvenile rough green snakes. However, adults have low survivorship, which may partly explain why these snakes become sexually mature early and lay rather large clutches annually. The main causes of mortality are environmental factors (hot, dry conditions) and predation. This species has an average life expectancy of 5 years, but they can reach up to 8 years.
Status: wild: 8 years.
Status: wild: 8 (high) years.
Status: wild: 5 years.
- Plummer, M. 1985. Demography of Green Snakes (Opheodrys aestivus). Herpetologica, Vol. 41, No. 4: 373-381.
- Plummer, M. 1997. Speed and Endurance of Gravid and Nongravid Green Snakes, Opheodrys aestivus. Copeia, Vol. 1997, No. 1: 191-194.
Lifespan, longevity, and ageing
Rough green snakes reproduce sexually with internal fertilization. These snakes are promiscuous, with males leaving almost immediately after copulation (Richmond, 1956). Courtship behavior of rough green snakes consists of visual orientation of males towards females, approach, body contact, and body alignment. Some motor patterns that are displayed during these stages are dorsal crawling, chin rubbing, tail waving, and head jerking. Once aligned with a female, a male begins with tail search copulatory attempts in energetic spurts followed by periods of motionlessness. On average, alignment is accomplished in about 2:45 minutes and the copulatory sequences average about 16:04 minutes (Goldsmith, 1988).
Mating System: polygynandrous (promiscuous)
Rough green snakes reach sexual maturity at 21 months in males and 21 to 33 months in females (Plummer, 1985). Although they breed every spring, fall matings have been noted (Mitchell, 1994). The gestation period can range from 5 to 12 weeks, depending on temperatures, and they typically lay their eggs during June and July (Plummer, 1990). Clutch size is 3 to 12 soft-shelled eggs (Mitchell, 1994). Males first breed in the spring of their second year, usually around 21 months. However only half of females participate in breeding during their second spring, while the other half delays an additional 12 months. Reproductively mature females can range from 360 to 400 mm snout-vent length, while sexually-mature males average 300 mm (Plummer, 1985).
Breeding interval: Breeding occurs once yearly.
Breeding season: Rough green snakes breed in the spring.
Range number of offspring: 3 to 12.
Average number of offspring: 6.2.
Range gestation period: 5 to 12 weeks.
Average gestation period: 6 weeks.
Range age at sexual or reproductive maturity (female): 21 to 33 months.
Range age at sexual or reproductive maturity (male): 20 to 21 months.
Average age at sexual or reproductive maturity (male): 21 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; oviparous
Female rough green snakes nearing oviposition leave their usual arboreal habitat to travel on the ground away from the shoreline. They seek out hollows in dead or living trees, decaying logs, under rocks or under boards in sandy soil. Such areas provide sufficient moisture levels for egg-laying. These locations are usually about 30.0 m (+/- 9.0 m) away from the shoreline. After oviposition, females return to the shoreline and resume her arboreal post. Females have no further contact with their eggs after hatching (Plummer, 1990).
Parental Investment: no parental involvement; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female)
- Mitchell, J. 1994. The Reptiles of Virginia. Washington and London: Smithsonian Institution Press.
- Goldsmith, S. 1988. Courtship Behavior of the Rough Green Snake, Opheodrys aestivus (Colubridae: Serpentes). The Southwestern Naturalist, Vol. 33, No. 4: 473-477.
- Goldsmith, S. 1984. Aspects of the Natural History of the Rough Green Snake, Opheodrys aestivus (Colubridae). The Southwestern Naturalist, Vol. 29, No. 4: 445-452.
- Plummer, M. 1990. Nesting Movements, Nesting Behavior, and Nest Sites of Green Snakes (Opheodrys aestivus) Revealed by Radiotelemetry. Herpetologica, Vol. 46, No. 2: 190-195.
- Plummer, M. 1985. Growth and Maturity in Green Snakes (Opheodrys aestivus). Herpetoligica, 41: 28-33.
- Plummer, M. 1990. High Predation on Green Snakes, Opheodrys aestivus. Journal of Herpetology, Vol. 24, No. 3: 327-328.
- Richmond, N. 1956. Autumn Mating of the Rough Green Snake. Herpetologica, Vol. 12, No. 4: 325.
Eggs are laid mainly in late June-July in Arkansas and Oklahoma. Clutch size averages 5-6 in Arkansas and Oklahoma. Eggs hatch in 5-12 weeks, July-October (August-early September in Arkansas). In Arkansas, males first breed at 21 months (spring of 3rd calendar year), females at 21 months or 33 months (Plummer 1985; Aldridge et al., 1990, Amphibia-Reptilia 11:165-172).
Rough Green Snake mating occurs in spring and fall. The female lays 3 to 12 smooth, rather hard, capsule-shaped eggs, 28 mm long. Young hatch in 5 to 12 weeks and mature in 1 to 2 years. (Behler and King 1979)
Molecular Biology and Genetics
Statistics of barcoding coverage: Opheodrys aestivus
Public Records: 0
Specimens with Barcodes: 3
Species With Barcodes: 1
Rough green snakes are listed as a species of least concern. Due to their apparent population stability, no conservation efforts are planned.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Large range in southeastern United States and northeastern Mexico; common in many areas.
Intrinsic Vulnerability: Moderately vulnerable
Global Short Term Trend: Relatively stable (=10% change)
Comments: Extent of occurrence, area of occupancy, number of subpopulations, and populations size probably are relatively stable overall, with local declines associated with habitat loss or climate variation (Plummer 1997).
Global Long Term Trend: Increase of 10-25% to decline of 30%
Degree of Threat: Medium
Comments: No major threats are known. Locally, clearing of wooded wetlands and wooded borders of aquatic habitats is a potential threat, as is pesticide application in such habitats.
Global Protection: Few to several (1-12) occurrences appropriately protected and managed
Comments: In the United States, this snake is probably effectively protected in at least several areas of federal, state, and private lands (e.g., national parks and wildlife refuges, state wildlife management areas).
Needs: Protect several large tracts of optimal habitat well dispersed throughout the range. Discourage application of pesticides in or near wooded wetlands.
Relevance to Humans and Ecosystems
There are no known adverse effects of Opheodrys aestivus on humans.
Although not common pets, domestication of these snakes has become increasingly popular because they are easy to care for.
Positive Impacts: pet trade
Opheodrys aestivus, commonly known as the rough green snake, is a nonvenomous North American colubrid. It is sometimes called grass snake or green grass snake, but these names are more commonly applied to the smooth green snake (Opheodrys vernalis). The European colubrid called grass snake (Natrix natrix) is unrelated. The rough green snake is docile, often allowing close approach by humans, and seldom bites.
The rough green snake (Opheodrys aestivus) is bright green above and has a yellowish belly, affording it excellent camouflage in green vegetation. It has keeled dorsal scales, which are arranged in 17 rows at midbody. It grows up to 116 cm (45½ inches) in total length and is very thin.
The rough green snake ranges throughout the Southeastern United States, from Florida, north to New Jersey, Indiana, and west to Central Texas. The snake is commonly found in the Piedmont and Atlantic Coastal Plain, but is not found in the higher elevations of the Appalachian Mountains. It is also found in northeastern Mexico, including the state of Tamaulipas and eastern Nuevo León.
Its preferred habitat is moist meadows and woodlands, often near water. It is highly arboreal, frequently found climbing in low vegetation, and is also a good swimmer. However, it is often found on the ground as well. Unlike many snakes, it is largely diurnal.
Its diet consists mostly of insects and other terrestrial arthropods, but some snails and tree frogs are eaten as well. This snake is not a constrictor—most prey are grabbed and simply swallowed alive.
The rough green snake breeds in spring, and sometimes again in fall. Females lay 2-14 eggs, occasionally in a communal nest shared by more than one female. Up to 75 eggs have been found in one such nest. The nest site varies: under boards, under bark in rotting stumps, in deep mulch, or under a rock. Hatchlings from spring breeding typically emerge in August or September, and are about 18–20 cm (7-8 inches) in total length.
The rough green snake is widespread and is not of conservation concern, in general. However urban development, especially the reduction of vegetation near waterways, may reduce their numbers. Many are killed on roads, and they may be susceptible to poisoning by pesticides used on their insect prey.
- Northern rough green snake, Opheodrys aestivus aestivus (Linnaeus, 1766)
- Florida rough green snake, Opheodrys aestivus carinatus Grobman, 1984
- Boulenger, G.A. 1894. Catalogue of the Snakes in the British Museum (Natural History), Volume II., Containing the Conclusion of the Colubridæ Aglyphæ. Trustees of the British Museum. London. xi + 382 pp., Plates I.- XX. (Contia æstiva, p. 258.)
- Stejneger, L., & T. Barbour. 1917. A Check List of North American Amphibians and Reptiles. Harvard University Press. Cambridge, Massachusetts. 125 pp. (Opheodrys aestivus, p. 78.)
- Smith, H.M., and E.D. Brodie, Jr. 1982. Reptiles of North America: A Guide to Field Identification. Golden Press. New York. 240 pp. ISBN 0-307-13666-3. (Opheodrys aestivus, pp. 188-189.)
- Aardema et al. Amphibians and Reptiles of North Carolina—accessed 29 May 2006
- Conant et al. (1998). A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Boston: Houghton Mifflin. ISBN 0-395-90452-8.
- Cook, Will. Carolina Nature—accessed 29 May 2006.
- Gibbons, Whit, Michael E. Dorcas, and J. Whitfield Gibbons (2005). Snakes Of The Southeast. Athens, Georgia: University of Georgia Press. ISBN 0-8203-2652-6.
- Martof et al. (1980). Amphibians and Reptiles of the Carolinas and Virginia. Chapel Hill: University of North Carolina Press. ISBN 0-8078-4252-4.
- Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2006. Animal Diversity Web. Accessed May 29, 2006.
- Palmer, William M., Alvin L. Braswell, Renaldo Kuhler (1995). Reptiles of North Carolina. Chapel Hill: University of North Carolina Press. ISBN 0-8078-2158-6.
- Schmidt, K.P., and D.D. Davis. 1941. Field Book of Snakes of the United States and Canada. G.P. Putnam's Sons. New York. 365 pp. (Opheodrys aestivus, pp. 118–120, Figure 27. + p. 332, Plate 12.)
- University of Georgia, Savannah River Ecological Laboratory, Animal Fact Sheets—accessed 1 June 2006
- University of Georgia, Savannah River Ecological Laboratory, Reptiles and Amphibians of South Carolina and Georgia—accessed 1 June 2006
- Wright, A.H., and A.A. Wright. 1957. Handbook of Snakes of the United States and Canada. Comstock. Ithaca and London. 1105 pp. (in 2 volumes) (Opheodrys aestivus, pp. 551–555, Map 43., Figure 164.)
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Names and Taxonomy
Comments: Grobman (1984) recognized four subspecies, based on scutellation variation: aestivus, majalis, carinatus, and conanti (the last two newly described). See Grobman (1992) and Collins (1992) for conflicting opinions on the validity of O. aestivus subspecies. These subspecies "generally have not been recognized by the herpetological community...because the distinctions among them were based on one or two differences in variable [and environmentally labile] scale characters and on outmoded taxonomic practices" (Walley and Plummer 2000).
Oldham and Smith (1991) demonstrated several significant categorical differences between O. aestivus and O. vernalis, indicative of a long history of divergent evolution, and assigned the latter species to a new genus (Liochlorophis), leaving aestivus as the only member of the genus Opheodrys.