General Description: The Dekay’s Brownsnake is a small terrestrial snake, with adults ranging from 10–12 inches (25.4–30.5 cm) in length. The background coloration is tan, brown, or reddish brown, typically with a pale middorsal stripe. This stripe may be bordered with black dots, though this is absent in some individuals. The top of the head is dark in coloration and two dark blotches are present on the neck giving an appearance of a collar. The belly is off-white with no markings. Juvenile coloration is similar to adult coloration. Scales are keeled and the anal scale is divided. Dekay’s Brownsnakes are similar in appearance to the Red-bellied Snake (Storeria occipitomaculata), but can easily be differentiated by the presence of a pale belly (Red-bellied Snakes have a red belly).
Behavior: Dekay’s Brownsnakes 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. Hibernacula are typically rocky outcrops or small mammal burrows. Earthworms are the primary prey of Dekay’s Brownsnakes, though slugs and snails may also be consumed.
Reproduction: Mating is thought to occur in the early spring after emergence from overwintering sites. Dekay’s Brownsnakes are viviparous, giving birth to 3–31 live young in the late summer. Sexual maturity is reached in 2–3 years.
Habitat: Dekay’s Brownsnakes use many different habitats including riparian woodlands, wet meadows, and residential areas throughout their large range.
Species Range: This species has a large distribution across much of the eastern half of the United States.
South Dakota Range: Dekay’s Brownsnakes are South Dakota’s rarest species of snake. Only a single individual has been collected from Roberts County in northeastern South Dakota. South Dakota populations represent the northwestern-most extent of this species.
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