Ring-necked Snake

Diadophis punctatus, commonly known as the ring-necked snake or ringneck snake, is a small, harmless species of colubrid snake found throughout much of the United States, as well as south in Central Mexico and as far north as Quebec, Canada. Ring-necked snakes are generally fossorial and somewhat secretive, by nature, and, as a nocturnal species, are rarely seen during the daytime. These snakes are believed to be fairly abundant throughout most of their range, though no scientific evaluation supports this hypothesis. Scientific research is lacking for the species, despite their apparently common status, and more in-depth investigations are greatly needed. It is the only species within the genus Diadophis and, currently, 14 subspecies are identified, though many herpetologists question the morphologically based classifications.

The ring-necked snake is perhaps best known for its unique defensive posture: when threatened, it curls its tail into a tight coil, partially rolls onto its back, and shows its bright red-orange underside and ventral surface. In nature, vivid coloration on an animal generally serves as a warning to others that it is not afraid of delivering a dose of venom, or that it is poisonous if eaten; this "false warning" coloration is a form of mimicry, a survival adaptation in which a non-venomous species (i.e., the ring-necked snake) has evolved brighter coloration, similar to truly venomous species, and used it to their advantage. Another example is seen in certain milksnakes and kingsnakes (Lampropeltis sp.) which have red, yellow, white or black stripes, an adaptation meant to confuse predators by visually mimicking the venomous coral snakes (Elapidae) which share much of their range.

Description

Ring-necked snakes are fairly similar in morphology throughout much of their distribution.

Its dorsal coloration is solid olive, brown, bluish-gray to smoky black, broken only by a distinct yellow, red, or yellow-orange neck band. A few populations in New Mexico, Utah, and other distinct locations do not have the distinctive neck band. In another population throughout the Coastal Plains across the United States, the rings around their neck are often incomplete. Additionally, individuals may have reduced or partially colored neck bands that are hard to distinguish; coloration may also be more of a cream color rather than bright orange or red. Head coloration tends to be slightly darker than the rest of the body, with tendencies to be blacker than grey or olive. Ventrally, the snakes exhibit a yellow-orange to red coloration broken by crescent-shaped black spots along the margins. Some individuals lack the distinct ventral coloration, but typically retain the black spotting. Rarely do individuals lack both the ventral and neck band coloration, so the use of those two characteristics is the simplest way to distinguish the species.