Reptiles of North Carolina
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NC Records

Agkistrodon contortrix - Eastern Copperhead


Agkistrodon contortrix
Photo: Steve Hall and Alvin Braswell
Agkistrodon contortrix
Photo: J. Mickey
Agkistrodon contortrix
Photo: Jim Petranka and Becky Elkin
Taxonomy
Class: Reptilia Order: Serpentes Family: Viperidae Subfamily: Crotalinae Other Common Name(s): Copperhead
Taxonomic Comments: Agkistrodon comprises eight species of venomous pitvipers. Most of the diversity of this genus is found within the United States and Mexico, with a couple species ranging south into Central America. Earlier spellings of the genus as "Ancistrodon" are not considered correct. Kraus et al. (1996), among others, showed that "Agkistrodon" in the Eastern Hemisphere are not closely related to those in North America, and revalidated the genus Gloydius for those taxa. Thus, Agkistrodon is restricted to North (and Central) America.

Species Comments: Agkistrodon contortrix, the Eastern Copperhead, is one of two Agkistrodon (and one of five pitvipers) in North Carolina. It found across the eastern United States, ranging from Massachusetts to Georgia (with a limited population in the Florida Panhandle), west to Texas and extreme southeastern Nebraska. In North Carolina, this species occurs statewide, with the exception of the Outer Banks.

Previously, five subspecies of Copperhead were recognized based on color and pattern, two of which were found in North Carolina: A. c. contortrix, the Northern Copperhead, in the Mountains; and A. c. mokasen (sometimes considered a hybrid "contortrix X mokasen" population), the Southern Copperhead, found throughout the Piedmont and Coastal Plain. Molecular systematics have shown clearly that the subspecific identifications are incorrect (Burbrink and Guiher, 2015). Only two species of Copperhead are now considered valid, and all populations in North Carolina are referred to A. contortrix, the Eastern Copperhead, with no subspecies recognized.

The generic epithet Agkistrodon is derived from the Greek ancistron, "fishhook". The specific epithet contortrix is derived from the Latin contortus, for "twisted" or "intricate".

Taxonomic References: Gloyd and Conant (1990); Kraus et al. (1996); Campbell and Lamar (2004); Burbrink and Guiher (2015)
Identification
Description: Copperheads are medium-sized, stout pitvipers, with relatively large angular heads distinct from the neck. Adults are pinkish to dark brown, with hourglass or "Hershey's Kiss"-shaped crossbands that are thin middorsally and widen laterally. These crossbands have darker edges and lighter centers, and are sometimes broken or asymmetrical. Darker spots of pigment can often be seen between crossbands and within their light centers. The venter is pale, mottled or distinctly spotted with various shades of gray, brown, or black. On the lateral head, a thin postorbital stripe runs to the rear of the jaw. The head is typically a burnt orange-copper color, lighter below the eyes and across the labials.

Juveniles and neonates have bright green, yellowish, or chartreuse tail tips, which usually fade with age.
Morphological Features: Copperheads typically have 23 keeled dorsal scale rows. Ventral counts range from 140-154 in NC specimens (Palmer and Braswell, 1995), with 42-50 subcaudals and an undivided anal plate. Head scale counts are typically: 8 supralabials, 9-10 infralabials, 1 loreal, 2 preoculars, 3-5 postoculars and suboculars, 2 nasals, and multiple rows of temporals. Palmer and Braswell (1995) noted some variation in scalation across multiple specimens.

Copperheads have a maximum recorded total length of 134.6 cm (53 inches), though most are smaller. Palmer and Braswell (1995) reported a 116.8 cm male specimen from NC. Tail lengths account for only around 12-18% of total length. Sexual dimorphism is weak, though males reach larger sizes and have more subcaudals on average than females.

Copperheads are solenoglyphous, meaning they have elongated, hollow fangs that direct venom like a hypodermic needle. These fangs are extended out during a strike, and folded into the mouth when it is closed. Copperheads are venomous, and should not be handled. Their venom is hemotoxic, meaning it works by attacking the blood and causing hemorrhaging; local swelling, pain, and hemorrhaging at the bite site are common symptoms.

Copperheads are not aggressive unless threatened, but bites often occur on unsuspecting individuals when they accidentally step on or near a concealed snake, or place their hand close to one. Copperheads (of both species) account for the majority of snakebite incidents in the United States, but generally are not life-threatening provided medical attention is sought; fewer than ten deaths have been recorded as a result of this species since the 1960s, despite thousands of reported bites.
Technical Reference: Gloyd and Conant (1990); Palmer and Braswell (1995); Ernst and Ernst (2003, 2011); Campbell and Lamar (2004)
Field Guide Descriptions: Beane et al. (2010).
Online Photos:    Google   iNaturalist   GBIF
Observation Methods: Copperheads are common in North Carolina, and active both during the day and at night. Many are flipped under cover objects (sometimes multiple under the same piece) or found crossing roads at night. They can be readily sampled using drift fences or coverboard arrays.
Distribution in North Carolina
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: Copperheads are primarily a species of forests and woodlands, although they are occasionally found out in adjoining fields (Palmer and Braswell, 1995). Hardwoods, pine flatwoods, and pocosins are all used and they also make some use of wooded residential areas (Beane et al.,2010).
Life History and Autecology
Breeding and Courtship: Sexual maturity is reached at body lengths greater than 47 cm. As with the closely related Cottonmouth, two mating periods for Copperheads occur: the first in spring (April to May) and the second in fall (September to October).
Reproductive Mode: Copperheads are ovoviviparous, giving birth to young enclosed in an amniotic sac; young are typically born in late summer to fall (July to October). Litters average 7 neonates.

Neonates are approximately 21–24 cm in total length and weigh 10 g on average. Neonates often display a bright chartreuse tail tip. Contrary to popular belief, neonate and juvenile Copperheads are not more venomous (or more likely to envenomate) than adults; juvenile venom glands are substantially smaller, and thus venom capacity is much smaller.
Terrestrial Life History: Copperheads are active both day and night, though typically more crepuscular/nocturnal during the hottest months. They can be found under surface cover or sitting under or near logs, rocks, or manmade objects like trash and dilapidated buildings. Copperheads are also commonly found in small groups even outside of winter hibernacula, though variation in grouping activity may occur ontogenetically and/or geographically (Ernst and Ersnt, 2003). Though primarily terrestrial, they will climb trees and small bushes, and occasionally swim across small creeks. Occurrence records in North Carolina are from every month but January; most are from late summer and early fall (July–September).

Home range estimates are not known from North Carolina, but elsewhere are fairly large and may differ between males and females. In Alabama, home range estimates averaged nearly 18 hectares (180,000 m2) for males and 4 hectares (40,000 m2) for gravid females (Sutton et al., 2017). Average home range size for Copperheads in Kentucky was approximately 7 hectares with a wide range (0.9–31.2 ha; Flaherty and Gienger, 2020). In Connecticut, average activity ranges also differed between males (17.5 hectares) and females (5 hectares; Smith et al., 2009).
General Ecology
Adverse Environmental Impacts
Status in North Carolina
NHP State Rank: S5
Global Rank: G5

Photo Gallery for Agkistrodon contortrix - Eastern Copperhead

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

Recorded by: J. Hall, J. Sealy, K. Bischof
Transylvania Co.
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Recorded by: K. Bischof
Transylvania Co.
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Recorded by: michael wilson
Harnett Co.
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Recorded by: Michael Wilson
Harnett Co.
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Recorded by: K. Bischof, D. Schafer
Transylvania Co.
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Recorded by: K. Bischof
Transylvania Co.
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Recorded by: Caleb Garner
Wake Co.
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Recorded by: Caleb Garner
Wake Co.
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Recorded by: Andrew W. Jones, James Cadolino
Polk Co.
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Recorded by: J. Mickey
Wilkes Co.
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Recorded by: Erich Hofmann and Kayla Weinfurther
New Hanover Co.
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Recorded by: K. Bischof
Transylvania Co.
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Recorded by: Travis McLain
Transylvania Co.
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Recorded by: Travis McLain
Transylvania Co.
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Recorded by: K. Bischof
Transylvania Co.
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Recorded by: Erich Hofmann and Kayla Weinfurther
Columbus Co.
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Recorded by: Erich Hofmann and Kayla Weinfurther
Columbus Co.
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Recorded by: Erich P. Hofmann and Kayla Weinfurther
Columbus Co.
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Recorded by: Erich P. Hofmann and Kayla Weinfurther
Columbus Co.
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Recorded by: A. Ranson
Durham Co.
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Recorded by: Sam Bluestein
Hyde Co.
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Recorded by: Sam Bluestein
Hyde Co.
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Recorded by: K. Bischof
Transylvania Co.
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Recorded by: J. Mickey
Wilkes Co.
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Recorded by: K. Bischof
Transylvania Co.
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Recorded by: J. Mickey
Wilkes Co.
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Recorded by: K. Bischof
Transylvania Co.
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Recorded by: J. Mickey
Wilkes Co.
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Recorded by: Hunter Phillips
Wayne Co.
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Recorded by: J. Mickey
Wilkes Co.
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