General Description: The Smooth Greensnake is a small terrestrial snake, with adults ranging from 12–20 inches (30.5–50.8 cm) in length. These snakes are solid, bright green in coloration and have a white or light yellow underside. Juvenile coloration is similar to adult coloration. Scales are non-keeled, giving individuals a smooth appearance, and the anal scale is divided. Smooth Greensnakes should not be confused with any other South Dakota snakes species, as no others are solid green in coloration. Adult North American Racers (Coluber constrictor) can be olive green in coloration with a light yellow underside but are significantly larger than Smooth Greensnakes. At similar sizes, juvenile North American Racers are patterned.
Behavior: Smooth Greensnakes are active from April to September and may even be active into October provided warmer temperatures. Similar to most other snakes, this species is solitary in behavior. Individuals can be found in close proximity while they are overwintering in den sites and when males seek out females during the reproductive season. Smooth Greensnakes feed primarily on small invertebrates and earthworms and do not constrict their prey. Individuals often overwinter in insect or mammal burrows.
Reproduction: Smooth Greensnakes breed shortly after emerging from hibernacula in the spring and females will lay 3–11 eggs in late July or August. Females retain eggs in their bodies for longer periods of time compared to many other snakes and therefore, once eggs are laid, they typically hatch within a month.
Habitat: Smooth Greensnakes can be found in wet meadows, prairies, and woodlands, but have also been found in residential and suburban areas.
Species Range: This species is distributed across much of New England and throughout the Great Lakes region, with isolated populations occurring throughout the Great Plains and the Rocky Mountains from Iowa and Missouri to New Mexico and Utah.
South Dakota Range: Smooth Greensnakes can be found in the Black Hills as well as in the northeastern and southeastern corners of the South Dakota.
South Dakota Status: This species is monitored by the South Dakota Natural Heritage Program. Any sightings of this species should be reported to South Dakota Game, Fish and Parks (report observation).
Account written by Drew R. Davis and Lanian M. Florke