Reptiles of North Carolina
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Sole representative of Elapidae in NC
NC Records

Micrurus fulvius - Harlequin Coralsnake


Micrurus fulvius
Photo: K. Futch, C. Edwards
Taxonomy
Class: Reptilia Order: Serpentes Family: Elapidae Other Common Name(s): Eastern Coral Snake
Taxonomic Comments: Micrurus is a highly diverse genus of dangerously venomous elapid snakes, currently consisting of more than 80 species. Most of the diversity of this genus is found in South America; only two species are native to the United States.

Species Comments: Micrurus fulvius, the Harlequin Coralsnake, is the only member of the genus in North Carolina. It is restricted to the southeastern United States, ranging from southern North Carolina to Florida. In North Carolina, where this species reaches its northern limit, it is only found in the southeastern Coastal Plain.

Previously, the Texas Coralsnake M. tener was considered a subspecies of M. fulvius, but molecular data showed they are distinct taxa, and the split is widely supported (Castoe et al., 2012). No subspecies of M. fulvius are now recognized.

The generic epithet Micrurus is derived from the Greek mikros, "small", and oura, "tail". The specific epithet fulvius is derived from the Latin fulvus, for orange or orange-yellow/tawny.

Taxonomic References: Roze and Tilger (1983); Campbell and Lamar (2004)
Identification
Description: Coralsnakes are medium-sized, slender snakes with black snouts. Bands of red, yellow, and black encircle the entire body; the red portions are usually bordered by the yellow, and often have some black mottling.

It is worth pointing out that the colloquialism "Red on Black: Friend of Jack; Red on Yellow: Kills a Fellow" is not a full-proof mechanism for delineating deadly venomous Coralsnakes from nonvenomous colubrids. Especially in Florida, numerous atypical specimens have been found that violate this presumption. Additionally, this colloquialism does not work outside of the United States. As with all snakes, it is best to avoid attempting to handle anything if you are not certain of the identification.
Morphological Features: Coralsnakes typically have 15 smooth dorsal scale rows. Ventral counts range from 199-226 in NC specimens (Palmer and Braswell, 1995), with 27-41 subcaudals and a divided anal plate. Head scale counts are typically: 7 supralabials, 7 infralabials, no loreal, 1 elongated preocular, 2 postoculars, 2 nasals, and 1+1 temporals. Palmer and Braswell (1995) noted minor variation in scalation across the 25 specimens they examined.

Coralsnakes have a maximum recorded total length of 121.3 cm (47.7 inches), though most are much smaller. Palmer and Braswell (1995) reported a 91.7 cm female specimen from NC. Tail lengths account for only around 8-13% of total length. Males have more tail bands, fewer body bands, longer tails, more subcaudals, and fewer ventrals than females.

Coralsnakes are proteroglyphous, meaning their fangs are short, fixed to the front of their maxilla, and have a channel or groove to direct venom. They are dangerously venomous, and should not be handled. The venom of Coralsnakes is neurotoxic, meaning it attacks the nervous system; envenomation results in difficulty breathing, muscle weakness, and slurred speech. Unlike the bite of pitvipers, Coralsnake bites may leave no visible mark.

Importantly, the myth that Coralsnakes must "chew" to envenomate a person is not true; venom can be injected with just a brief or partial bite. However, bites are uncommon, and have a low mortality rate provided the person bitten receives proper medical attention quickly. Only one mortality has been reported in the United States since the 1960s, and this was largely attributable to the victim not seeking medical attention immediately (Norris et al., 2009).
Technical Reference: Palmer and Braswell (1995); Ernst and Ernst (2003); Campbell and Lamar (2004)
Field Guide Descriptions: Palmer and Braswell (1995); Ernst and Ernst (2003); Campbell and Lamar (2004); Beane et al. (2010).
Online Photos:    Google   iNaturalist   GBIF
Observation Methods: Coralsnakes are rare in North Carolina. They are occasionally found active in areas with porous sandy soil. Others may be within cover, or when crossing roads.
Distribution in North Carolina
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: Coral Snakes are highly fossorial and are associated with well-drained sandy soils. In North Carolina, it occurs essentially only in xeric, pine-oak sandhill habitats in the Coastal Plain (Palmer and Braswell, 1995).
Biotic Relationships: Coralsnakes consume elongate squamate prey almost exclusively (Greene, 1973; 1984; Jackson and Franz, 1981; Palmer and Braswell, 1995; Krysko and Arbdelfattah, 2002; Hampton, 2011). Recorded prey include skinks (including Plestiodon fasciatus, P. inexpectatus, and Scincella lateralis), glass lizards (Ophisaurus ventralis), and both venomous and nonvenomous snakes (including Carphophis amoenus, Cemophora coccinea, Coluber constrictor, Diadophis punctatus, Farancia abacura, Lampropeltis elapsoides, Liodytes pygaea, Opheodrys aestivus, Pantherophis guttatus, Sistrurus miliarius, Storeria dekayi, S. occipitomaculata, and Tantilla coronata); rodents and anurans are rarely taken but have been reported, and amphisbaenians are known prey in Florida. Cannibalism on smaller conspecifics is also known to occur.

Reported predators of Coralsnakes include predatory birds (hawks and kestrels), ophiophagous snakes (kingsnakes and other coralsnakes), bullfrogs, and domestic cats (Ernst and Ernst, 2003).
Life History and Autecology
Breeding and Courtship: Coralsnakes reach sexual maturity at snout-to-vent lengths greater than 50 cm. Mating occurs in the spring (April and May). Very little is known about its reproductive habits in North Carolina.
Reproductive Mode: Coralsnakes are oviparous and typically lay eggs in late spring and summer (May to July) that hatch in late summer or fall (August to September). Clutches average 6 white, adherent, very elongated eggs averaging 32–38 mm long.

Hatchlings are approximately 19 cm in total length.
Terrestrial Life History: Coralsnakes are secretive, fossorial, and diurnal; they are most often encountered under surface cover or reportedly excavated from under ground, though they are also found active on road or in areas with porous, sandy soils, especially in the morning. They have been recorded in North Carolina in every month except December, but most records are from May–October.

Much remains to be learned about the natural history of our native Coralsnake, and home range estimates are not known for this species.
General Ecology
Adverse Environmental Impacts
Status in North Carolina
NHP State Rank: S1
Global Rank: G5
Status in North Carolina: E

Photo Gallery for Micrurus fulvius - Harlequin Coralsnake

5 photos are shown.

Recorded by: Jamie Adams
New Hanover Co.
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Recorded by: Andy Davis
New Hanover Co.
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Recorded by: K. Futch, C. Edwards
New Hanover Co.
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Recorded by: K. Futch, C. Edwards
New Hanover Co.
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Recorded by: Bruce Smithson and Carolina Bird Club
New Hanover Co.
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