Opheodrys vernalis
Smooth Green Snake

Smooth green snakes are are only native to the Nearctic region. They are found from northeastern Canada, west to Saskatchewan, south through Illinois and Virginia. There are isolated populations in areas of the western United States as well, including Wyoming, New Mexico, Iowa, Missouri, Colorado, Texas, and northern Mexico. (Harding, 1997)

Smooth green snakes are found in moist, grassy areas, usually in prairies, pastures, meadows, marshes, and lake eges. They can also be found in open forested areas. They are most often found on the ground or climbing in low bushes. They also bask on and hide beneath rocks, logs, and other debris. (Harding, 1997)

Smooth green snakes are the only snakes in eastern North America that are entirely bright green on their upper surfaces. This coloration camouflages them well in their grassy habitats. The head is slightly wider than the neck and is green above and white below. The belly is white to pale yellow. Occasionally smooth green snakes can be brown or tan in coloration. The scales are smooth and total body length ranges from 30 to 66 cm. Males are usually smaller than females, but have longer tails. Newly hatched smooth green snakes measure 8.3 to 16.5 cm in length and tend to be less brightly colored than adults, often olive-green or bluish-gray. Smooth green snakes are harmless snakes, they are not venomous. (Harding, 1997)

Smooth green snakes mate in the spring and late summer. Females lay from 3 to 13 cylindrical eggs in shallow burrows, in rotting vegetation, or under logs or rocks. Females may share nest sites, each depositing their eggs into a single nest. Eggs are laid from June to September and the eggs hatch in August or September. Time to hatching varies quite a bit, from 4 to 30 days. This is partly a result of their ability to retain the eggs and incubate them in their body. Keeping the eggs inside the female would be beneficial to speed development because females can bask and maintain the warmth of their eggs if they are retained in her body. Young smooth green snakes mature in their second year. (Harding, 1997)

Once a female lays her eggs there is no further parental care of the young, though females may retain their eggs for varying amounts of time - thus warming them to speed development and protecting them from predators and injury. (Harding, 1997)

Lifespans in the wild of smooth green snakes are unknown. One captive individual lived for 6 years.

Smooth green snakes are active from April through October and are mainly solitary. In winter they hibernate with groups of other snakes, including other snake species. Hibernation sites include anthills and abandoned rodent burrows. Smooth green snakes are most active during the day, though they may be active mainly in the morning and evening in hot weather. (Harding, 1997)

As other snakes, smooth green snakes rely mainly on their sense of smell, vision, and their detection vibrations to locate prey. They mainly communicate with other snakes by chemical cues and through tactile cues. (Harding, 1997)

Smooth green snakes eat mainly insects. They prefer crickets, grasshoppers, and caterpillars, and will also eat beetles, spiders, centipedes, millipedes, snails, slugs, and sometimes amphibians. (Harding, 1997)

Smooth green snakes are probably eaten by birds, such as hawks and American crows, by large snakes, such as milk snakes, and by some mammals, such as raccoons and foxes. They rely on their bright green color to camouflage them under most circumstances. They are fast and agile and can escape quickly, but will bite and thrash if harassed and can smear attackers with a nasty-smelling fluid. (Harding, 1997)

Smooth green snakes influence the populations of their insect prey and serve as a food source for predators. (Harding, 1997)

Smooth green snakes help to control populations of insect pests where they are abundant. (Harding, 1997)

Smooth green snakes have been declining in numbers and local populations have been wiped out throughout their range. This is mainly the result of habitat destruction and pesticide use. Because their diet is mainly insects, they are particularly vulnerable to the effects of insecticides that are widely sprayed in agricultural areas. (Harding, 1997)

Smooth green snakes, as with most snakes, don't do well in captivity. They fail to eat and do not survive for long. (Harding, 1997)