DeKay's Brownsnake

Dorsally, S. dekayi is brown to gray with a lighter center stripe bordered by small black spots; ventrally, it is lighter brown or pink with small black dots at the ends of the ventral scales. Adults usually measure less than 12 inches (30 cm) in total length (including tail), but the record total length is 19+3⁄8 inches (49 cm). On average, juveniles measured 3 inches (7.68 cm) just after being born. The dorsal scales are keeled, and it has no loreal scale. Females exceed males in snout–vent length and number of ventral scales while males exceed females in tail length, head dimensions, and number of subcaudal scales.

S. dekayi is native to Southern Ontario and Quebec, most of the eastern half of the United States, through Mexico, Guatemala, Honduras, and possibly El Salvador. More specifically, this common species inhabits most wetland and terrestrial habitats east of the Great Plains from sea level to 1,400 meters (4,600 feet) above sea level.

Like other natricine snakes such as water snakes (genus Nerodia) and garter snakes (genus Thamnophis), S. dekayi is a viviparous species, giving birth to live young. Sexual maturity is reached at two to three years. Females have seasonal sperm storage that allows for delayed fertilization and parturition, which synchronize birth timing with peak prey availability. Mating takes place in the spring, after snakes emerge from brumation. Field studies have shown that males use pheromone-based mate searching to find receptive females. Between 3 and 41 young are born in late summer.

The specific name, dekayi, is in honor of American zoologist James Ellsworth De Kay (1792–1851), who collected the first specimen on Long Island, New York, while the generic name, Storeria, honors American zoologist David Humphreys Storer. This is the only North American snake whose binomial is a double honorific – that is, both the generic name and the specific name honor people.