Reptiles of North Carolina
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NC Records

Carphophis amoenus - Common Wormsnake


Photo: Steve Hall
Photo: J. Mickey
Photo: j.wyche
Taxonomy
Class: Reptilia Order: Serpentes Family: COLUBRIDAE Subfamily: Dipsadinae Other Common Name(s): Eastern Worm Snake
Taxonomic Comments: Carphophis consists of two species of small, fossorial dipsadine snakes endemic to the eastern United States. No comprehensive molecular phylogeny of the genus has been completed. Carphophis amoenus is the sole representative of the genus in North Carolina. It is found primarily east of the Mississippi River, ranging across much of the Atlantic Seaboard from Massachusetts south to Georgia, and across to southeastern Louisiana.

Species Comments: Carphophis amoenus, the Common Wormsnake, was described by Say (1825) as "Coluber amoenus", before being moved to the genus Carphophis by Gervais (1843).

Two subspecies are traditionally recognized on the basis of the condition of the internasal and prefrontal scales: C. a. amoenus (internasals and prefrontals separate) and C. a. helenae (internasals and prefrontals fused into a single scale). Only C. a. amoneus (the Eastern Wormsnake) is represented in North Carolina.

It is worth noting that a large area of integradation exists where the two subspecies' ranges meet (causing variation in the condition of the internasals and prefrontals) and a preliminary mitochondrial phylogeny in an unpublished thesis found that the genetic lineages did not correspond to current subspecific taxonomy (Baggett, 2019).

The generic epithet Carphophis comes from a combination of the Greek karphos, meaning a twig or dry particle in a woodland habit, and ophis, meaning "snake". The specific epithet amoenus is Latin for "pleasing or lovely", in reference to the snake's smooth appearance.

Taxonomic References: Ernst and Ernst (2003); Ernst et al. (2003a, 2003b)
Identification
Description: Common Wormsnakes are small, patternless fossorial snakes with flat, pointed heads equally as wide as their cylindrical body. As their common name implies, worm snake may be confused for earthworms at first glance due to their habits and appearance. Their dorsum is patternless, a uniform chestnut to brown (occasionally appearing gray or blue in specimens preparing to shed). The head is also patternless, maintaining the same color as the dorsum; only the dark eyes stand out. The venter is usually pink; the dorsal and ventral colors are typically distinctly separate, and the ventral color may be visible up to the first or second scale row. Hatchlings are typically darker above, with a more distinct division between dorsal and ventral coloration.
Morphological Features: Common Wormsnakes typically have 13 smooth scale rows at midbody; in some specimens the number increases to 15 closer to the tail. Their dorsal scales typically exhibit a noticeable "sheen" (opalescence). Ventral counts range from 109–145 (NC specimens: 113-140; Palmer and Braswell, 1995), with 22-41 subcaudals and a divided anal plate. The tail ends in a short, notably conical spine. Head scale counts are typically as follows: 5 supralabials, 6 infralabials, 1 nasal, 1 elongated loreal, no preoculars, 1 postoculars, and 1+2 or 1+3 temporals. Some variation in scalation was noted by Palmer and Braswell (1995).

These are small snakes, with a maximum reported total length of 34.2 cm (13.5 inches). Tail lengths range from 11-21% of total length. Females reach larger size than males, have smaller 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. Males may exhibit anal ridges on the body scales near the anal plate. There is no consistent color or pattern dimorphism in this species in our state.

Common Wormsnakes lack any sort of enlarged rear fang or venom-producing capability. They are completely harmless to humans and pets, and never attempt to bite.
Technical Reference: Palmer and Braswell (1995); Ernst and Ernst (2003); Ernst et al. (2003a, 2003b).
Field Guide Descriptions: Palmer and Braswell (1995); Ernst and Ernst (2003); Beane et al. (2010).
Online Photos: iNaturalist, Reptile Database, HerpMapper   Google   iNaturalist   GBIF
Observation Methods: Common Wormsnakes may be sampled using drift fences with pitfall traps and cover objects. They are frequently incidentally encountered under cover, even in human-altered habitats such as yards and gardens.
Distribution in North Carolina
Distribution Comments: Common Wormsnakes are found across the state, though few records exist from the Outer Banks except in Dare Co. The highest elevation recorded for this species in North Carolina is 1311 m (Swain Co.). Though they are secretive, sampling efforts often return high numbers (e.g. Willson and Dorcas, 2004; Pittman and Dorcas, 2006), and they may be among the most abundant snake species in the state.
Distribution Reference: Palmer and Braswell (1995); Ernst and Ernst (2003); Beane et al. (2010)
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: Common Wormsnakes are abundant in mesic forests. Although they can sometimes be found out in open, hebaceous areas, that occurs only where they are located close to forests (Palmer and Braswell, 1995; Beane et al., 2010). They also turn up frequently in semi-wooded urban or suburban neighborhoods, like several other snakes that are small enough to avoid much human notice.
Environmental and Physiological Tolerances: To avoid dessication, Common Wormsnakes are primarily fossorial and nocturnal. They are able to tolerate a range of soil temperatures, air temperatures, and relative humidities, and are known to burrow deep into soil or rotting logs to survive the winter (Ernst and Ernst, 2003; Diefenbacher and Pauley, 2014; Jones and Tupper, 2017).
Biotic Relationships: The Common Wormsnake preys on primarily earthworms (Lumbricidae). Other reported prey include dipteran larvae (Tabanidae; Uhler et al., 1939), arachnids, beetles (Diefenbacher and Pauley, 2014) and in one instance, a small brook salamander (Eurycea; Clark, 1970). In North Carolina, only earthworms have been reported as prey (Brown, 1979; Palmer and Braswell, 1995; Willson and Dorcas, 2004).

Common Wormsnakes are known prey of many ophiophagous snakes, birds including bluebirds, thrushes, turkeys, and hawks, mammals (cats and opossums), and even mudpuppies (Braswell and Ashton, 1985; Palmer and Braswell, 1995; Stanback and Mercadante, 2009; Roble, 2013; Herrera and Cove, 2020).
Life History and Autecology
Breeding and Courtship: Female Common Wormsnakes are generally considered sexually mature when they reach at least 17cm snout-to-vent length (SVL). Breeding is thought to occur primarily in late spring and early summer.
Reproductive Mode: Eggs develop in early summer and are typically laid June-July in clutches of 1-12 eggs. Eggs are white, leathery, and range from 1.1-2.5 cm in length (Ernst and Ernst, 2003).

Hatchlings emerge in late summer to early fall (August-September in NC per Palmer and Braswell, 1995), and range from 8.8-11.4 cm in total length. They are typically darker dorsally with brighter pink ventrals than adults.
Terrestrial Life History: Common Wormsnakes are primarily nocturnal, spending the day under leaf litter, stumps and logs, and other cover objects. Although they have been recorded in North Carolina in every month of the year, most activity occurs between April and October in the Coastal Plain and Piedmont, and May to August in the Mountains.

These snakes are completely harmless and pose no threat to humans or pets. When handled, they never bite, but may attempt to burrow into the fingers and occasionally will use their small tail spine to poke the hand, though never with enough force to break the skin.

Home ranges have not been estimated for populations in North Carolina. Barbour et al. (1969) found an average home-range size of 253 m2 across 10 individuals from Kentucky; they displayed no evidence of homing ability after displacement.
General Ecology
Population Ecology: Common Wormsnakes are often the most abundant species in suitable habitat (e.g. Willson and Dorcas, 2004). Famously, in one hour Carl Ernst and students collected over 100 individuals under cover objects in a 100m area 'along a hillside overlooking the Kentucky River' (Ernst and Ernst, 2003). Known sex ratios range from approximately 1–1.9:1 (male:female; Russell and Hamlin, 1999; Ernst and Ernst, 2003); in North Carolina a study in the Western Piedmont recovered a 1.35:1 male:female ratio (Willson and Dorcas, 2004).
Community Ecology: Several other species of small-bodied snakes feed on earthworms, and may serve as direct competition to Common Wormsnakes in that regard. Similarly, skinks, salamanders, and small frogs may also serve as direct competition for prey. Common Wormsnakes have been found in fire ant (Solenopsis invicta) mounds in the winter (Palmer and Braswell, 1995). Additionally, Jones (2014) noted finding Common Wormsnakes in active formicid ant nests; the ants apparently did not display aggression towards the Common Wormsnakes, suggesting there may be an understudied relationship between these taxa.
Adverse Environmental Impacts
Habitat Loss: Loss of suitable habitat has led to the species becoming rarer in the northern part of its range (Ernst and Ernst, 2003).
Habitat Fragmentation: Common Wormsnakes have been found to be more abundant in mixed-pine hardwoods than managed forests in some areas (McLeod and Gates, 1998). Other studies have found no significant difference in response to canopy gaps or clearcutting/retention treatments (Greenberg, 2001; Felix et al., 2010).
Effects of Introduced Species/Induced Increases of Native Species: Little is known about the direct effect of introduced species on Wormsnakes. Feral hogs (Sus scrofa) may pose a threat to these and other semi-fossorial snakes, given their propensity for rooting in the leaf litter and ground surface.

In one study of invasive earthworms (Amynthas agrestis) in the Great Smoky Mountains National Park, the authors noted an increase in Wormsnake encounters, suggesting these snakes may predate this novel food source (Snyder et al. 2011).
Interactions with Humans: Common Wormsnakes are infrequently, but occasionally, killed by motor vehicles when crossing roads. They may be accidentally killed when encountered in gardens, compost areas, or yards, and like all snakes in the area, they are occasionally killed when found by humans out of fear.
Status in North Carolina
NHP State Rank: S5
Global Rank: G5
Populations: Although we lack detailed population level studies of Common Wormsnakes for most of the state, their abundance and distribution is considered stable.
Protected Lands: In North Carolina, Common Wormsnakes are known from at least 17 state parks, all four national forests, one national park, and one national military park (DPR NRID, accessed 2022-07-05; iNaturalist, accessed 2022-07-05; NCSM Online Collections, access 2022-07-05; VertNet, accessed 2022-07-05).
Status Comments: Common Wormsnakes are secure in the state, given their high relative abundance and near state-wide distribution. The susceptibility of this species to the emerging fungal pathogen Ophidiomyces ophidiodiicola (Oo; snake fungal disease) is not known at this time but could be detrimental. Similarly, Ranavirus (Rv) infection may contribute to behavioral changes and mortality in reptiles. The majority of Common Wormsnakes (9 of 11) tested by Lentz et al. (2021) were positive for Rv, though none were positive for Oo. Two individuals in Virginia and Maryland were found to be infected with Oo, though without clinical signs (Fuchs et al., 2020).

Photo Gallery for Carphophis amoenus - Common Wormsnake

30 photos are shown.

Recorded by: M. Gentry, T. Chisholm
Iredell Co.
Comment: 		Recorded by: Steve Hall and Dee Stuckey
Orange Co.
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Recorded by: Andrew W. Jones
Polk Co.
Comment: 		Recorded by: Travis McLain
Cabarrus Co.
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Recorded by: Travis McLain
Cabarrus Co.
Comment: 		Recorded by: Travis McLain
Cabarrus 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
Columbus Co.
Comment: 		Recorded by: C. Teague, B. Bockhahn, C. Blake
Beaufort Co.
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Recorded by: A. Lasley
Burke Co.
Comment: 		Recorded by: J. Mickey
Wilkes Co.
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Recorded by: Erich Hofmann
Craven Co.
Comment: 		Recorded by: Erich Hofmann
Craven Co.
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Recorded by: Guy McGrane
Wilkes Co.
Comment: 		Recorded by: j.wyche & Nathanial Williams
Gates Co.
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Recorded by: j.wyche
Gates Co.
Comment: 		Recorded by: M. Griffin
Stokes Co.
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Recorded by: Erich Hofmann
Craven Co.
Comment: 		Recorded by: j.wyche
Gates Co.
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Recorded by: K. Bischof
McDowell Co.
Comment: 		Recorded by: K. Bischof
Transylvania Co.
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Recorded by: K. Bischof
Transylvania Co.
Comment: 		Recorded by: Joe Mickey
Alleghany Co.
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Recorded by: K. Bischof
Beaufort Co.
Comment: 		Recorded by: K. Bischof, S. Fambrough, M. Smith
Beaufort Co.
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Recorded by: J. Shimel
Halifax Co.
Comment: 		Recorded by: JWP, JJH
Surry Co.
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Recorded by: Steve Hall and Dawson Sather
Orange Co.
Comment: 		Recorded by: Steve Hall
Orange Co.
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