Reptiles of North Carolina
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NC Records

Diadophis punctatus - Ring-necked Snake


Photo: Steve Hall
Photo: j.wyche
Taxonomy
Class: Reptilia Order: Serpentes Family: COLUBRIDAE Subfamily: Dipsadinae Other Common Name(s): Ringneck Snake
Taxonomic Comments: Diadophis, as currently considered, is a monotypic genus of small dipsadid snakes found throughout much of the United States and northern Mexico. Originally described as part of Coluber, the name Diadophis was first applied to these snakes in 1853.
Species Comments: Diadophis punctatus, the Ring-necked Snake, is the sole representative of this genus. It is found primarily throughout the eastern and central United States, ranging from southeastern Canada through central Mexico. Additional populations are found along the Pacific Coast, making this species one of the most wide-spread fossorial/semi-fossorial species in the US. In North Carolina, it can be found essentially statewide.

Various authorities recognize between 12 and 14 subspecies on the basis of morphology including ventral patterning, coloration, scalation, and size. In North Carolina, two subspecies are traditionally recognized: D. p. edwardsii, the Northern Ring-Necked Snake, found throughout the western portion of the state; and D. p. punctatus, the Southern Ring-Necked Snake, found along Atlantic Coast. A large zone of integradation is thought to occur throughout most of the Piedmont. These subspecies were traditionally separated by the completeness of the neckband (complete in D. p. edwardsii; incomplete in D. p. punctatus), a row of black midventral spots down the body (absent in D. p. edwardsii; present in D. p. punctatus), and supralabial count (usually 7 in D. p. punctatus; usually 8 in D. p. edwardsii; however, these characteristics are highly variable, even within populations.

Recent molecular studies have shown that the traditional morphology-based subspecies are not consistent with molecular lineages (Fontanella et al., 2008; 2018; Fontanella and Siddall, 2010). At least three mitochondrial DNA lineages can be found in North Carolina: the "Mid-Atlantic Lineage" along the Coastal Plain and eastern Piedmont, the "Northeast Lineage" in the western Piedmont and Mountains, and the "Cumberland Mountains Lineage" in extreme southwestern NC. Substantially more work and more thorough genetic sampling is needed to clarify the taxonomy of this species.

For the purposes of this site, all submitted records of Ring-necked Snakes will be assigned to the D. punctatus binomial.

The generic epithet Diadophis is derived from the Latin diadem, "headband", and ophis, "snake", referencing the distinctive neck band. The specific epithet punctatus is derived from the Latin punctum, meaning "spotted", in reference to the ventral spotting on some individuals.

Taxonomic References: Fontanella et al. (2008; 2018; 2021); Fontanella and Siddall (2010).
Identification
Description: The following description and morphological features are primarily based on North Carolina specimens. Ring-necked Snakes are small snakes with slender bodies and flat/rounded heads slightly wider than the neck. Their dorsum is a uniform slate-gray to black, with a cream or yellow neckband that may be complete or interrupted dorsally; the neckband may vary in thickness but typically takes up one to two scale rows near the back of the head/anterior neck. The venter is usually yellow or orange, with the dorsal color encroaching laterally to varying degrees. Dark, semi-circular to semi-triangular midventral spots on the posterior of the ventrals are present in many individuals to varying degrees, ranging from dark, distinct, and complete to lacking completely. The anterior top of the head is consistent with the dorsal coloration, while the labials and underside of the head are typically cream to yellow, sometimes with black spots or smudges. Hatchlings resemble adults.
Morphological Features: Ring-necked Snakes typically have 15 smooth, scale rows at midbody. Ventral counts range from 130-169 (Palmer and Braswell, 1995), with 33-71 subcaudals and a divided anal plate. Head scale counts are typically as follows: 7-8 supralabials, 7-8 infralabials, 2 nasals, 1 internasal, 1 loreal, 2 preoculars, 2 postocular, and 1+2 temporals. Palmer and Braswell (1995) noted inter- and intrasubspecific variation in scalation across multiple specimens in NC.

These are typically small snakes (larger in populations from the western USA), though Palmer and Braswell (1995) reported one female NC specimen with a total length of 50.5 cm (19.8 inches). Tail lengths range from 16-27% of total length. Females typically reach larger size than males, have smaller average tail lengths relative to body, and average more ventral scales and fewer subcaudal scales. Males are smaller on average but with longer tails relative to body length, meaning fewer ventrals and more subcaudals.

Ring-necked Snakes do possess enlarged posterior teeth and a Duvernoy's gland capable of producing venom that it uses to subdue prey; however, this appears to be variable across populations and published studies have shown that some populations are lacking this adaptation (O'Donnell et al., 2007). Differences in dentition and venom secretions may factor into the differences in diet between populations of Ring-necked Snakes across North America. Regardless, these snakes are essentially harmless to humans and pets, and almost never attempt to bite. When captured, they typically writhe about, feign death, and/or tuck their heads under their coiled body while flashing the underside of their tail.
Technical Reference: Palmer and Braswell (1995); Ernst and Ernst (2003).
Field Guide Descriptions: Palmer and Braswell (1995); Ernst and Ernst (2003); Beane et al. (2010).
Online Photos:    Google   iNaturalist   GBIF
Observation Methods: Ring-necked Snakes may be sampled using drift fences with pitfall traps and cover objects. They may be incidentally encountered under cover objects.
Distribution in North Carolina
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: Ring-necked Snakes are associated primarily with mesic forests, including both hardwoods and pine-dominated stands (Palmer and Braswell, 1995; Beane et al., 2010).
Biotic Relationships: The diet of Ring-necked Snakes varies geographically, as does much of the biology and ecology of this species complex. The smaller populations in the eastern United States take smaller prey than the large-bodied western populations. In North Carolina, most diet records are of small vertebrates or invertebrates: salamanders (including Desmognathus, Eurycea, and Plethodon), ground skinks (Scincella lateralis), and earthworms have all been reported (Hamilton and Pollack, 1956; Brown, 1979; Palmer and Braswell, 1995; Willson and Dorcas, 2004).

Documented predators of Ring-necked Snakes in the eastern United States include ophiophagous snakes (kingsnakes, racers, copperheads, milksnakes), birds (hawks and bluebirds), and raccoons (Palmer and Braswell, 1995; Stanback and Mercadante, 2009; Gotte, 2016).
Life History and Autecology
Breeding and Courtship: Males reach sexual maturity at body lengths around 20 cm, and females are likely similar. Mating occurs in the spring (May) but has also been reported from early Fall (September and October) in parts of its range.
Reproductive Mode: Ring-necked Snakes are oviparous and typically lay eggs in summer (June to July) that hatch in later summer or early Fall. Clutches average 5 elongate, adherent, rough-shelled eggs that average 21–23 mm long (Palmer and Braswell, 1995).

Hatchlings are approximately 11–13 cm in total length, and weigh approximately 1 g (Palmer and Braswell, 1995; Ernst and Ernst, 2003). Note that reproductive data for this species likely varies across its large range.
Terrestrial Life History: Ring-necked Snakes are primarily nocturnal but may also be crepuscular; the authors of this site have found them active on roads at dusk. During the day, they are often found under surface cover including rocks and pine bark. They are almost chiefly terrestrial, but occasionally are found a couple meters off the ground under loose bark. They have been recorded in North Carolina from February–November, but most activity occurs in the spring and most records are from April to August. Ring-necked snakes will use burrows, rotting logs/stumps, and other deep crevices as hibernacula, and will often return to the same places within a home range.

Home range estimates are not known from North Carolina, but in Kansas average home ranges are elongated and average approximately 6400 m2 (Fitch, 1975).
General Ecology
Adverse Environmental Impacts
Status in North Carolina
NHP State Rank: S5
Global Rank: G5

Photo Gallery for Diadophis punctatus - Ring-necked Snake

50 photos are available. Only the most recent 30 are shown.

Recorded by: Steve Hall, Dee Stuckey, and Savannah Hall
Orange Co.
Comment: Found under debris in a powerline		Recorded by: Andrew W. Jones
Polk Co.
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Recorded by: Andrew W. Jones
Polk Co.
Comment: 		Recorded by: Guy McGrane
Watauga Co.
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Recorded by: K. Bischof
Transylvania Co.
Comment: 		Recorded by: A. Ranson
Durham Co.
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Recorded by: K. Bischof
Transylvania Co.
Comment: 		Recorded by: J. Mickey
Surry Co.
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Recorded by: Pat Momich
Madison Co.
Comment: 		Recorded by: Pat Momich
Madison Co.
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Recorded by: Erich Hofmann and Kayla Weinfurther
Craven Co.
Comment: 		Recorded by: Erich Hofmann
Craven Co.
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Recorded by: Erich Hofmann
Craven Co.
Comment: 		Recorded by: Z. Lunn
Scotland Co.
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Recorded by: Z. Lunn
Scotland Co.
Comment: 		Recorded by: T. Stafford
Moore Co.
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Recorded by: Erich Hofmann
Craven Co.
Comment: 		Recorded by: j.wyche
Gates Co.
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Recorded by: J.Phillips
Wake Co.
Comment: 		Recorded by: J.Phillips
Wake Co.
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Recorded by: A Lasley
Burke Co.
Comment: 		Recorded by: T. Nergart
Transylvania Co.
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Recorded by: J. Summers
Harnett Co.
Comment: 		Recorded by: j.wyche
Gates Co.
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Recorded by: j.wyche
Gates Co.
Comment: 		Recorded by: j.wyche
Gates Co.
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Recorded by: S. Carpenter
Orange Co.
Comment: 		Recorded by: A. Byrge
Avery Co.
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Recorded by: J. Wyche
Gates Co.
Comment: 		Recorded by: Jane Wyche
Gates Co.
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