Diadophis punctatus, commonly known as the ringneck snake or ring-necked snake, is a species of colubrid snake. It is found throughout much of the United States, central Mexico, and south eastern Canada. Ring-necked snakes are secretive, nocturnal snakes that are rarely seen during the day time. They are slightly venomous but their non-aggressive nature and small rear-facing fangs pose little threat to humans who wish to handle them. They are best known for their unique defense posture of curling up their tails exposing their bright red-orange posterior, ventral surface when threatened.
Dorsal coloration is solid olive, brown, bluish gray to black, broken only by a distinct yellow, red, or yellow-orange neck band. 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
Ring-necked snakes use a combination of constriction and envenomation to secure their prey. The snakes do not have a true venom gland, but they do have an analogous structure called the Duvernoy’s gland derived from the same tissue.
Ring-necked snakes first strike and then secure the prey using constriction. Next they maneuver their mouths forward ensuring that the last maxillary tooth punctures the skin allowing the venom to enter the prey’s tissue. Ring-necked snakes are rarely aggressive to larger predators suggesting that their venom evolved as a feeding strategy rather than a defense strategy. Rather than trying to bite a predator, the snake winds up its tail into a corkscrew, exposing the brightly colored belly.
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