Reptile Description

Opheodrys vernalis
Smooth Green Snake

Family: colubrid snakes (Colubridae)

Order: lizards and snakes (Squamata)

General Description: The smooth green snake is a small and slender species, with a tapered head and tail. This species is very striking, and has a bright green back and a cream or white colored underside. Its eyes are large and its pupils round, as is characteristic of non-venomous species. The tongue, which is constantly flicked in and out to "smell" its surroundings, is bright red with a black tip. Juvenile smooth green snakes are olive green, blue-gray, or brown, but they turn the characteristic green of their species after their first skin shedding.

Abundance: uncommon

Origin: native

Distribution: This species has been documented throughout the northern half of the U.S. and southern Canada. Its range extends from New England in the east to Montana in the west. In addition, a few isolated reports of this species have occurred in the central and western U.S. Within Montana, smooth green snakes have been documented in three northeastern counties: Roosevelt, Daniels, and Sheridan. This species has the most restricted distribution of any snake in Montana.

Habitat: Smooth green snakes are found primarily in grassy meadows, marshes, and fields, as well as on the fringes of wooded areas. They prefer to live in moist areas, and rarely leave the green areas where they are best camouflaged.

Life History: There are many aspects about the reproductive behavior of smooth green snakes that are still unknown. Many herpetologists believe that mating occurs in May or June. One or two clutches of eggs are laid in July or August under rocks or logs. Larger females tend to lay more eggs. The eggs are oval and white with thin shells and blunt ends, and are only one inch long. Hatching occurs in about a month, and the young reach sexual maturity at 3 years of age.

Similar: The eastern racer appears somewhat similar to the smooth green snake, but is much larger and more robust. The eastern racer also has a very distinctive coloration of muted green or brown, while the smooth green snake is a very bright grass-green.

Enemies: This species is predated by hawks and other birds of prey, as well as other snake species such as common and terrestrial garter snakes.

Did You Know: The smooth green snake is active primarily during the day, when it spends much of its time searching for small insects and spiders. Although it is a good climber, it stays primarily on the ground. Its green color is an excellent form of camouflage in its preferred habitat of grasslands or marshes. It may overwinter in communal dens with many of its own species, or other snake species such as garter snakes. Apart from its coloration, it has few defense mechanisms, although it will secrete smelly substances from its cloacae when captured and handled. The smooth green snake is listed as a species of concern by state conservation agencies, due to its declining population and the scarcity of sightings. Because its diet consists solely of invertebrates, it may be very vulnerable to pesticides sprayed on crops. Roadside mortality is also a possible contributing factor to the decline of this species.

Contributors:
  • Corissa Crowder
  • Frank Janes
Glossary:
  • Diurnal
    Active chiefly in the daytime.
References:
  • John L. Behler and F. Wayne King. National Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1995.
  • Robert C. Stebbins. Western Reptiles and Amphibians. Houghton Mifflin Co. Boston 2003.
  • Werner, J. K., Maxell, B.A., Hendricks, P., and D. L. Flath. Amphibians and Reptiles of Montana. Mountain Press Publishing Company, 2004.