Diadophis punctatus
Encyclopedia
The ringneck snake or ring-necked snake (Diadophis punctatus) is a colubrid
snake species. 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. Ring-necked snakes are believed to be fairly abundant throughout most of their range though no scientific evaluation supports this theory. Scientific research is lacking for the ring-necked snake and more in-depth investigations are greatly needed. It is the only species
within the genus
Diadophis, and currently fourteen subspecies
are identified, but many herpetologists question the morphologically-based classifications.
Dorsal
coloration is solid olive, brown, bluish gray to black, broken only by a distinct yellow, red, or yellow-orange neck band. There are a few populations in New Mexico, Utah, and other distinct locations that do not have the distinctive neck band. Additionally individuals may have a reduced or partially colored neck band that is 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. Sometimes individuals lack the distinct ventral coloration but typically retain the black spotting. Rarely do individuals lack both the ventral or neck band coloration so use of those two characteristics are the most simple way to distinguish the species.
Size also varies across the species distribution. Typically adults measure 25-38 cm (10-15 inches), except for D. punctatus regalis which measures 38-46 cm (15-18 inches). First year juvenile snakes are typically about 20 cm (4 inches) and grow about 2-5 cm (¾-2 inches) a year depending on the developmental stage or resource availability.
Ring-necked snakes have smooth scales with 15-17 scale rows at mid body. Males typically have small tubercles on their scales just anterior to the vent which are usually absent in females.
continuous through the gulf coast of north Texas. Distribution moves inland into northern Minnesota continuing diagonally through the US to include all of Iowa, eastern Nebraska, and most of Kansas. In the western US the distribution is significantly less continuous, with spotty distinct population segments through most of the Pacific Northwest. Populations extend from south-central Washington continuing along the extreme west coast into Mexico. Population segments extend inland into western Idaho, through southern Nevada, into central Utah, and continuing south through Arizona and central Mexico.
s. Preference seems to be determined by areas with abundant cover and denning locations spaces. Northern and western species are found within open woodland
s near rocky hillsides, or in wetter environments with abundant cover or woody debris. Southern species exist primarily within riparian and wet environments, especially in more arid
habitats. Stebbins (2003) identified the species as a snake of moist habitats, identifying that moist soil
conditions were the preferred substrate. Ring-necked snakes are also not found above an elevation of 2200 meters. In northern regions, dens are also important in identifying suitable ring-necked snake habitat. Dens are usually shared communally, and are identifiable by an existent subsurface crevasse or hole that is deep enough to prevent freezing temperatures. Since it is a woodland reptile, it can commonly also be found under wood or scraps. Because of the hot weather, they tend to make holes and burrow or they decide to hide under rocks or any suitable material. They are normally found in flatland forests.
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. Most subspecies are rear-fanged with the last maxillary teeth on both sides of the upper jaw being longer and channeled; the notable exception is D. punctatus edwardsii which is fangless. The venom is produced in the Duvernoy's gland located directly behind the eye. It then drains out of an opening at the rear of the maxillary tooth. 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.
Ring-necked snakes are primarily nocturnal or highly crepuscular
, though some diurnal activity has been observed. Individuals are sometimes found during the day, especially on cloudy days, sunning themselves to gain heat. Yet, most individuals lie directly under surface objects that are warmed in the sun and use conduction with that object to gain heat. Even though ring-necked snakes are highly secretive, they do display some social structure; but the exact social hierarchies have never been evaluated. Many populations have been identified to have large colonies of more than 100 individuals, and some reports identify that some smaller colonies occupy the same microhabitats.
and fend for themselves without parental care.
Colubrid
A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...
snake species. 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. Ring-necked snakes are believed to be fairly abundant throughout most of their range though no scientific evaluation supports this theory. Scientific research is lacking for the ring-necked snake and more in-depth investigations are greatly needed. It is the only species
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
within the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Diadophis, and currently fourteen subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are identified, but many herpetologists question the morphologically-based classifications.
Physical description
Ring-necked snakes are fairly similar in morphology throughout much of their distribution.Dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
coloration is solid olive, brown, bluish gray to black, broken only by a distinct yellow, red, or yellow-orange neck band. There are a few populations in New Mexico, Utah, and other distinct locations that do not have the distinctive neck band. Additionally individuals may have a reduced or partially colored neck band that is 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. Sometimes individuals lack the distinct ventral coloration but typically retain the black spotting. Rarely do individuals lack both the ventral or neck band coloration so use of those two characteristics are the most simple way to distinguish the species.
Size also varies across the species distribution. Typically adults measure 25-38 cm (10-15 inches), except for D. punctatus regalis which measures 38-46 cm (15-18 inches). First year juvenile snakes are typically about 20 cm (4 inches) and grow about 2-5 cm (¾-2 inches) a year depending on the developmental stage or resource availability.
Ring-necked snakes have smooth scales with 15-17 scale rows at mid body. Males typically have small tubercles on their scales just anterior to the vent which are usually absent in females.
Distribution
Ring-necked snakes are fairly common throughout much of the United States extending into Southeastern Canada and central Mexico. Eastern populations cover the entire eastern seaboard from the Gulf of Saint LawrenceGulf of Saint Lawrence
The Gulf of Saint Lawrence , the world's largest estuary, is the outlet of North America's Great Lakes via the Saint Lawrence River into the Atlantic Ocean...
continuous through the gulf coast of north Texas. Distribution moves inland into northern Minnesota continuing diagonally through the US to include all of Iowa, eastern Nebraska, and most of Kansas. In the western US the distribution is significantly less continuous, with spotty distinct population segments through most of the Pacific Northwest. Populations extend from south-central Washington continuing along the extreme west coast into Mexico. Population segments extend inland into western Idaho, through southern Nevada, into central Utah, and continuing south through Arizona and central Mexico.
Habitat
Ring-necked snakes occur in a wide variety of habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s. Preference seems to be determined by areas with abundant cover and denning locations spaces. Northern and western species are found within open woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
s near rocky hillsides, or in wetter environments with abundant cover or woody debris. Southern species exist primarily within riparian and wet environments, especially in more arid
Arid
A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life...
habitats. Stebbins (2003) identified the species as a snake of moist habitats, identifying that moist soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
conditions were the preferred substrate. Ring-necked snakes are also not found above an elevation of 2200 meters. In northern regions, dens are also important in identifying suitable ring-necked snake habitat. Dens are usually shared communally, and are identifiable by an existent subsurface crevasse or hole that is deep enough to prevent freezing temperatures. Since it is a woodland reptile, it can commonly also be found under wood or scraps. Because of the hot weather, they tend to make holes and burrow or they decide to hide under rocks or any suitable material. They are normally found in flatland forests.
Behavior
The diet of the ring-necked snake consists primarily of smaller salamanders, worms and slugs, but they also sometimes eat lizards, frogs, and some juvenile snakes of other species. The frequency at which prey species are chosen is dependent on their availability within the habitat. Ring-necked snakes use a combination of constriction and envenomationEnvenomation
Envenomation is the process by which venom is injected into some animal by the bite of a venomous animal. Many kinds of animals, including mammals , reptiles , spiders , insects , employ venom for hunting and for self defense...
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. Most subspecies are rear-fanged with the last maxillary teeth on both sides of the upper jaw being longer and channeled; the notable exception is D. punctatus edwardsii which is fangless. The venom is produced in the Duvernoy's gland located directly behind the eye. It then drains out of an opening at the rear of the maxillary tooth. 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.
Ring-necked snakes are primarily nocturnal or highly crepuscular
Crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
, though some diurnal activity has been observed. Individuals are sometimes found during the day, especially on cloudy days, sunning themselves to gain heat. Yet, most individuals lie directly under surface objects that are warmed in the sun and use conduction with that object to gain heat. Even though ring-necked snakes are highly secretive, they do display some social structure; but the exact social hierarchies have never been evaluated. Many populations have been identified to have large colonies of more than 100 individuals, and some reports identify that some smaller colonies occupy the same microhabitats.
Reproduction
Ring-necked snakes usually mate in the spring. However, in some subspecies mating occurs in the fall, and delayed implantation occurs.. Females attract males by secreting pheromones from their skin. Once the male finds a female he starts by rubbing his closed mouth along the female’s body. Then the male bites the female around her neck ring maneuvering to align their bodies so sperm can be inserted into the female’s vent. Females lay their eggs in loose aerated soils under a rock or in a rotted log. Three to ten eggs are deposited in early summer and hatch in August or September. The egg is elongate with a white color contrasted by yellow ends. When hatched, juveniles are precocialPrecocial
In biology, the term precocial refers to species in which the young are relatively mature and mobile from the moment of birth or hatching. The opposite developmental strategy is called "altricial," where the young are born or hatched helpless. Extremely precocial species may be called...
and fend for themselves without parental care.
Subspecies
- D. p. acricus (Paulson, 1966) — Key ringneck snake
- D. p. amabilis (BairdSpencer Fullerton BairdSpencer Fullerton Baird was an American ornithologist, ichthyologist and herpetologist. Starting in 1850 he was assistant-secretary and later secretary of the Smithsonian Institution in Washington, D.C...
& GirardCharles Frédéric GirardCharles Frédéric Girard was a French biologist specializing in ichthyology and herpetology.Born in Mulhouse, France, he studied at the College of Neuchâtel, Switzerland as a student of Louis Agassiz. In 1847, he accompanied Agassiz as his assistant to Harvard...
, 1853) — Pacific ringneck snake - D. p. anthonyi (Van DenburghJohn Van DenburghJohn Van Denburgh was a U.S. herpetologist from California.He was born in San Francisco and enrolled at Stanford University in 1891. As of 1895, he organized the herpetology department of the California Academy of Sciences. In 1897 he got a Ph.D. from Stanford University. Additionally, he got an M.D...
& Slevin, 1942) — Todos Santos Island ringneck snake - D. p. arnyiDiadophis punctatus arnyiDiadophis punctactus arnyi, also known as the prairie ringneck snake, is a small, thin member of the Colubrid Family. The subspecific name is in honor of Samuel Arny, who collected the type specimen.-Geographic range:...
KennicottRobert KennicottRobert Kennicott was an American naturalist.-Biography:Kennicott was born in New Orleans and grew up in "West Northfield" , Illinois, a town in the prairie north of the then nascent city of Chicago....
, 1859 — prairie ringneck snake - D. p. dugesii (Villada, 1875) — Michoacan ringneck snake
- D. p. edwardsiiDiadophis punctatus edwardsiiThe Northern ringneck snake is a subspecies of Diadophis punctatus. The subspecific name is in honor of English ornithologist George Edwards, who collected the type specimen.-Description:...
(MerremBlasius MerremBlasius Merrem was a German naturalist.Merrem was born at Bremen, and studied at the university of Göttingen under Johann Friedrich Blumenbach. He developed an interest in zoology, particularly ornithology...
, 1820) — Northern ringneck snake - D. p. modestus (BocourtMarie Firmin BocourtMarie Firmin Bocourt was a French zoologist and artist.In zoology, Bocourt collaborated with Auguste Duméril. In 1861, he was sent to Thailand , where he explored the fauna and brought back an important collection of specimens...
, 1866) — San Bernardino ringneck snake - D. p. occidentalis (Blanchard, 1923) — Northwestern ringneck snake
- D. p. pulchellus (Baird & Girard, 1853) — coralbelly ringneck snake
- D. p. punctatus (LinnaeusCarolus LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1766) — Southern ringneck snake - D. p. regalisDiadophis punctatus regalisThe regal ringneck snake is a subspecies of ringneck snake found in the southwestern United States and northern Mexico.- Description :...
Baird & Girard, 1853 — regal ringneck snake - D. p. similis (Blanchard, 1923) — San Diego ringneck snake
- D. p. stictogenys (CopeEdward Drinker CopeEdward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
, 1860) — Mississippi ringneck snake - D. p. vandenburghii (Blanchard, 1923) — Monterey ringneck snake