Venom and Bites:
The copperhead has solenogiyphous fangs that tend to be 1.1-7.2 mm in length. The length of the snake relates to the length of the fangs; the longer the snake, the longer the fangs. Even newborn copperheads have fully functional fangs that are capable of injecting venom. These newborns have venom that is just as toxic as adults do. The fangs are replaced periodically with each snake having a series of five to seven replacement fangs in the gums behind and above the current functional fang.
The venom, which is highly hemolytic, causes massive hemorrhaging to the copperhead's prey. As for humans, recorded symptoms include pain, swelling, weakness, giddiness, breathing difficulty, hemorrhage, either an increased or decreased pulse, nausea, vomiting, gangrene, ecchymosis, unconsciousness, stupor, fever, sweating, headache and intestinal discomfort. The copperhead is the cause of many snakebites yearly but they are rarely fatal. Bites occur by accidentally stepping on or touching the snake, which tends to be well camouflaged with its surroundings. When touched, the copperhead quickly strikes or remains quiet and tries to crawl away. Sometimes when touched, they emit a musk that smells like cucumbers (Ernst 1989).
No special status federally, however it is listed in the state of Massachusetts as endangered (Umass 1999).
IUCN Red List of Threatened Species: least concern
The Copperhead is primarily a carnivore, as an adult eating mostly mice but also small birds, lizards, small snakes, amphibians and insects-especially cicadas (Conant and Collins 1998). The snakes are capable of swallowing prey that is several times larger than their own diameter. This is possible because they have a very flexible jaw and it has digestive juices that allow it to digest both bones and fur. Copperheads have fangs that inject its prey with a hemolytic venom (causes the breakdown of red blood cells) which subdues its prey, making it easy for the snake to swallow it. The copperhead seeks out its prey using its heat sensitive pits to detect objects that are warmer then its environment. This also enables them to find nocturnal mammalian prey (Ohio DNR 1999). Adult copperheads are primarily ambushers. When attacking large prey, the copperhead bites then releases immediately to allow the venom to take its effect then later tracks its prey. Whereas the smaller prey is held in its mouth until it dies (Ernst 1989). When the copperhead eats depends on the time of the year. They are most active April through late October, diurnal in the spring and fall, and nocturnal during the summer months (Ohio DNR 1999). When carrying young, some females will not eat at all because the embryos occupy so much of the body cavity. It has been found that some copperheads consume only eight meals in a single growing season. The only possible explanations for this could be due to a slow metabolism and/or difficulty finding prey ( Tyning 1990).
Young copperheads eat mostly insects, especially caterpillars, and use their yellow tipped tails to function as a worm-like lure to attract prey (Georgia Wildlife Federation 1999).
Overall, the species inhabits the Florida panhandle north to Massachusetts and west to Nebraska (Georgia Wildlife Federation 1999)
The Northern Copperhead (A. c. mokasen) inhabits northern Georgia and Alabama north to Massachusetts and west to Illinois.
The Southern Copperhead (A. c. contortrix) inhabits the Florida panhandle north to Southern Delaware and west to SE Missouri, SE Oklahoma and E Texas.
The Broad-banded Copperhead (A. contortrix laticinctus) ranges from northern Oklahoma to south-central Texas.
The Osage Copperhead (A. c. phaeogaster) lives in eastern Missouri to eastern Kansas and south to northeastern Oklahoma.
The Trans-pecos Copperhead (A. c. pictigaster) lives in west Texas.
Biogeographic Regions: nearctic (Native )
Copperheads prefer terrestrial to semi-aquatic habitats, which include rocky-forested hillsides and various wetlands (Tyning 1990). They have also been known to occupy abandoned and rotting slab or sawdust piles (Conant 1998).
Terrestrial Biomes: forest
Average lifespan
Status: captivity: 29.8 years.
Average length of adult copperheads is 30 inches. They have an unmarked copper-colored head, reddish-brown, coppery bodies with chestnut brown crossbands that constrict towards the midline. Copperheads are thick-bodied and have keeled scales.
There is a temperature sensitive pit organ on each side of the head between the eye and the nostril. There is a single row of scales beneath the tail (Schmidt 1941, Tyning 1990).
Tails have no rattle (Ernst 1989).
Young copperheads are 7-10 inches long and grayer in color than adults. They have a sulfur yellow tipped tail, which fades with age and is lost by age 3 or 4.
Copperheads are sexually dimorphic in size. Males have longer tails than females and females grow to greater lengths (Tyning 1990).
The head of the Northern Copperhead is a red, copper color with the rest of its body being pinkish to gray-brown with a dark chestnut colored hourglass shaped pattern. The hourglass pattern is narrow on the top of its back and wider on its sides. It has elliptical pupils and facial pits between its eyes and nostrils (Ohio DNR 1999).
The underside, belly area, of the northern subspecies is dark (Schmidt & Davis 1941).
The southern copperhead subspecies is similar to the northern copperhead but the coloration is paler and the crossbands fail to meet at the midline. Also the belly of the southern subspecies is light in color (Schmidt & Davis 1941).
Broad-banded copperheads have bright coloration with a sharp contrast between the pattern and the ground color. The crossbands are very broad at the midline and always meet. The belly is dark (Schmidt and Davis 1941).
The osage copperhead is similar to those of the northern subspecies but the crossbands are often edged in white (Conant and Collins 1998).
The belly of the Trans-pecos Copperhead is strongly patterned. Also there is a pale area located at the base of each broad crossband (Conant and Collins 1998).
Other Physical Features: heterothermic
Sexual Dimorphism: female larger
The life span of the copperhead is 18 years. Both sexes reach sexual maturity at 4 years when they are about two feet in length. However, Ernst (1989) notes that the age and size of maturity in the male copperhead is unknown. The breeding season is from February to May and from August to October. Females who breed in autumn can store the sperm until after she emerges from the overwintering site (Tyning 1990). The length of time that the sperm can be stored appears to differ depending on where it is being stored. If the sperm is stored in the cloaca, it only lasts a relatively short time, whereas if it is stored in the upper end of the oviducts in vascular tissues specialized as seminal receptacles it seems to last much longer (Ernst 1989). Copperheads have a gestation period of 3-9 months. They are a live-bearing snake, typically producing 2-10 young, where larger females produce larger broods. After birth, the female provides no direct care for the young (Tyning 1990).
Females are ovoviviparous. Eggs develop in the body of the female and hatch within or immediately after being expelled. They produce large, yolk-filled eggs and store the eggs in the reproductive tract for development. The embryo, during this time, receives no nourishment from the female, only from the yolk. The young are expelled in a membranous sac. At birth they weigh less than an ounce and are 7-10 inches in length (Ohio DNR 1999).
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; ovoviviparous
Average number of offspring: 6.
Average age at sexual or reproductive maturity (male)
Sex: male: 730 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 730 days.
The eastern copperhead (Agkistrodon contortrix),[3] also known simply as the copperhead, is a species of venomous snake, a pit viper, endemic to eastern North America; it is a member of the subfamily Crotalinae in the family Viperidae.
The eastern copperhead has distinctive, dark brown, hourglass-shaped markings, overlaid on a light reddish brown or brown/gray background. The body type is heavy, rather than slender. Neonates are born with green or yellow tail tips, which progress to a darker brown or black within one year. Adults grow to a typical length (including tail) of 50–95 cm (20–37 in).
In most of North America, it favors deciduous forest and mixed woodlands. It may occupy rock outcroppings and ledges, but is also found in low-lying, swampy regions. During the winter, it hibernates in dens or limestone crevices, often together with timber rattlesnakes and black rat snakes.[4] The eastern copperhead is known to feed on a wide variety of prey, including invertebrates (primarily arthropods) and vertebrates. Like most pit vipers, the eastern copperhead is generally an ambush predator; it takes up a promising position and waits for suitable prey to arrive.
As a common species within its range, it may be encountered by humans. Unlike other viperids, they often "freeze" instead of slithering away, due to its habit of relying on excellent camouflage, rather than fleeing.[5] Bites occur due to people unknowingly stepping on or near them.[6] Copperhead bites account for half of the treated snake bites in the United States.[7]
Five subspecies have been recognized in the past,[8] but recent genetic analysis had yielded new species information.
Its generic name is derived from the Greek words ankistron "hook, fishhook" and odon, variant of odous "tooth".[9][10] The trivial name, or specific epithet, comes from the Latin contortus (twisted, intricate, complex), which is usually interpreted to reference the distorted pattern of darker bands across the snake's back, which are broad at the lateral base, but "pinched" into narrow hourglass shapes in the middle at the vertebral area.[11][12]
Adults grow to a typical length (including tail) of 50–95 cm (20–37 in). Some may exceed 1 m (3 ft 3 in), although that is exceptional for this species.[13] Males do not typically exceed 74 to 76 cm (29 to 30 in) and weigh from 101.5 to 343 g (3+9⁄16 to 12+1⁄8 oz), with a mean of roughly 197.4 g (6+15⁄16 oz).[14] Females do not typically exceed 60 to 66 cm (23+1⁄2 to 26 in),[15][16] and have a mean body mass of 119.8 g (4+7⁄32 oz).[17] The maximum length reported for this species is 134.6 cm (53 in) for A. c. mokasen (Ditmars, 1931). Brimley (1944) mentions a specimen of A. c. mokasen from Chapel Hill, North Carolina, that was "four feet, six inches" (137.2 cm), but this may have been an approximation. The maximum length for A. c. contortrix is 132.1 cm (52 in) (Conant, 1958).[11]
The body is relatively stout and the head is broad and distinct from the neck. Because the snout slopes down and back, it appears less blunt than that of the cottonmouth, A. piscivorus. Consequently, the top of the head extends further forward than the mouth.[18]
The escalation includes 21–25 (usually 23) rows of dorsal scales at midbody, 138–157 ventral scales in both sexes, and 38–62 and 37–57 subcaudal scales in males and females, respectively. The subcaudals are usually single, but the percentage thereof decreases clinally from the northeast, where about 80% are undivided, to the southwest of the geographic range where as little as 50% may be undivided. On the head are usually 9 large symmetrical plates, 6–10 (usually 8) supralabial scales, and 8–13 (usually 10) sublabial scales.[11]
The color pattern consists of a pale tan to pinkish-tan ground color that becomes darker towards the foreline, overlaid with a series of 10–18 (13.4) crossbands. Characteristically, both the ground color and crossband pattern are pale in A. c. contortrix. These crossbands are light tan to pinkish-tan to pale brown in the center, but darker towards the edges. They are about two scales wide or less at the midline of the back, but expand to a width of 6–10 scales on the sides of the body. They do not extend down to the ventral scales. Often, the crossbands are divided at the midline and alternate on either side of the body, with some individuals even having more half bands than complete ones. A series of dark brown spots is also present on the flanks, next to the belly, and are largest and darkest in the spaces between the crossbands.
The belly is the same color as the ground color, but may be a little whitish in part. At the base of the tail are one to three (usually two) brown crossbands followed by a gray area. In juveniles, the pattern on the tail is more distinct: 7–9 crossbands are visible, while the tip is yellow. On the head, the crown is usually unmarked, except for a pair of small dark spots, one near the midline of each parietal scale. A faint postocular stripe is also present; diffuse above and bordered below by a narrow brown edge.[18]
Several aberrant color patterns for A. c. contortrix, or populations that intergrade with it, have also been reported. In a specimen described by Livezey (1949) from Walker County, Texas, 11 of 17 crossbands were not joined middorsally, while on one side, three of the crossbands were fused together longitudinally to form a continuous, undulating band, surmounted above by a dark stripe that was 2.0–2.5 scales wide.
In another specimen, from Lowndes County, Alabama, the first three crossbands were complete, followed by a dark stripe that ran down either side of the body, with points of pigment reaching up to the midline in six places, but never getting there, after which the last four crossbands on the tail were also complete. A specimen found in Terrebonne Parish, Louisiana, by Ernest A. Liner, had a similar striped pattern, with only the first and last two crossbands being normal.[18]
The eastern copperhead is found in North America; its range within the United States is in Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Mississippi, Missouri, Nebraska, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, and West Virginia. In Mexico, it occurs in Chihuahua and Coahuila. The type locality is "Carolina". Schmidt (1953) proposed the type locality be restricted to "Charleston, South Carolina".[2]
Unlike some other species of North American pit vipers, such as the timber rattlesnake and massasauga, the copperhead has mostly not re-established itself north of the terminal moraine after the last glacial period (the Wisconsin glaciation),[19] though it is found in southeastern New York and southern New England, north of the Wisconsin glaciation terminal moraine on Long Island.
Within its range, it occupies a variety of different habitats. In most of North America, it favors deciduous forest and mixed woodlands. It is often associated with rock outcroppings and ledges, but is also found in low-lying, swampy regions. During the winter, it hibernates in dens or limestone crevices, often together with timber rattlesnakes and black rat snakes.[4] In the states around the Gulf of Mexico, however, this species is also found in coniferous forest. In the Chihuahuan Desert of West Texas and northern Mexico, it occurs in riparian habitats, usually near permanent or semipermanent water and sometimes in dry arroyos (brooks).[11]
This species is classified as least concern on the IUCN Red List of Threatened Species (v3.1, 2001).[1] This means that relative to many other species, it is not at risk of extinction in the near future. The population trend was stable when assessed in 2007.[20]
In the Southern United States, copperheads are nocturnal during the hot summer, but are commonly active during the day during the spring and fall. Unlike other viperids, they often "freeze" instead of slithering away, and as a result, many bites occur due to people unknowingly stepping on or near them.[6] This tendency to freeze most likely evolved because of the extreme effectiveness of their camouflage. When lying on dead leaves or red clay, they can be almost impossible to notice. They frequently stay still even when approached closely, and generally strike only if physical contact is made. Like most other New World vipers, copperheads exhibit defensive tail vibration behavior when closely approached. This species is capable of vibrating its tail in excess of 40 times per second— faster than almost any other nonrattlesnake snake species.[5]
The eastern copperhead is a diet generalist and is known to feed on a wide variety of prey, including invertebrates (primarily arthropods) and vertebrates. A generalized ontogenetic shift in the diet occurs, with juveniles feeding on higher percentages of invertebrates and ectotherms, and adults feeding on a higher percentage vertebrate endotherms. Both juveniles and adults, though, feed on invertebrates and vertebrates opportunistically. The diet is also known to vary among geographic populations.[18]: 128–130 p. [11]: 254–255 p. [21]: 181–184 p.
Studies conducted at various locations within the range of the eastern copperhead (A. contortrix), including Tennessee,[22] Kentucky,[23] Kansas,[24] and Texas,[25] identified some consistently significant prey items included cicadas (Tibicen), caterpillars (Lepidoptera), lizards (Sceloporus and Scincella), voles (Microtus), and mice (Peromyscus). Accounts of finding large numbers of copperheads in bushes, vines, and trees seeking newly emerged cicadas, some as high as 40 feet above ground, have been reported from Texas by various herpetologists.[18]: 130 p. [26][27]: 347–348 p.
Other items documented in the diet include various invertebrates, e.g. millipedes (Diplopoda), spiders (Arachnida), beetles (Coleoptera), dragonflies (Odonata), grasshoppers (Orthoptera), and mantids (Mantidae), as well as numerous species of vertebrates, including salamanders, frogs, lizards, snakes, small turtles, small birds, young opossums, squirrels, chipmunks, rabbits, bats, shrews, moles, rats, and mice.[11]: 254–255 p. [21]: 181–184 p.
Like most pit vipers, the eastern copperhead is generally an ambush predator; it takes up a promising position and waits for suitable prey to arrive. One exception to ambush foraging occurs when copperheads feed on insects such as caterpillars and freshly molted cicadas. When hunting insects, copperheads actively pursue their prey.[28] Juveniles use a brightly colored tail to attract frogs and perhaps lizards, a behavior termed caudal luring (see video: [1]). Sight, odor, and heat detection are used in locating prey, although after the prey has been envenomated, odor and taste become the primary means of tracking. Smaller prey items and birds are often seized and held in the mouth until dead, while larger prey items are typically bitten, released, and then tracked until dead. Copperheads occasionally feed on carrion. Gravid females typically fast, although some individuals occasionally take small volumes of food.[11]: 254–255 p. [21]: 181–184 p. An individual may eat up to twice its body mass in a year. One study found an individual that ate eight times during an annual activity period, totaling 1.25 times its body mass.[29]
Eastern copperheads breed in late summer, but not every year; sometimes, females produce young for several years running, then do not breed at all for a time. They give birth to live young, each of which is about 20 cm (8 in) in total length. The typical litter size is four to seven, but as few as one, or as many as 20 may be seen. Their size apart, the young are similar to the adults, but lighter in color, and with a yellowish-green-marked tip to the tail, which is used to lure lizards and frogs.
A. contortrix males have longer tongue tie lengths than females during the breeding season, which may aid in chemoreception of males searching for females.[30]
Parthenogenesis is a natural form of reproduction in which growth and development of embryos occur without fertilization. A. contortrix can reproduce by facultative parthenogenesis, that is, they are capable of switching from a sexual mode of reproduction to an asexual mode.[31] The type of parthenogenesis that likely occurs is automixis with terminal fusion, a process in which two terminal products from the same meiosis fuse to form a diploid zygote. This process leads to genome-wide homozygosity, expression of deleterious recessive alleles, and often to developmental failure (inbreeding depression). Both captive-born and wild-born A. contortrix snakes appear to be capable of this form of parthenogenesis.[31]
Although venomous, eastern copperheads are generally not aggressive and bites are rarely fatal.[32] Copperhead venom has an estimated lethal dose around 100 mg, and tests on mice show its potency is among the lowest of all pit vipers, and slightly weaker than that of its close relative, the cottonmouth.[33] Copperheads often employ a "warning bite" when stepped on or agitated and inject a relatively small amount of venom, if any at all. "Dry bites" involving no venom are particularly common with the copperhead, though all pit vipers are capable of a dry bite.[34] Pit vipers that are dead are still dangerous and capable of producing venom in amounts that necessitate the use of antivenom.[35]
Bite symptoms include extreme pain, tingling, throbbing, swelling, and severe nausea. Damage can occur to muscle and bone tissue, especially when the bite occurs in the outer extremities such as the hands and feet, areas in which a large muscle mass is not available to absorb the venom. A bite from any venomous snake should be taken very seriously and immediate medical attention sought, as an allergic reaction and secondary infection are always possible.[36]
The venom of the southern copperhead has been found to hold a protein called "contortrostatin" that halts the growth of cancer cells in mice and also stops the migration of the tumors to other sites.[37] However, this is an animal model, and further testing is required to verify safety and efficacy in humans.[38]
The antivenom CroFab is used to treat copperhead envenomations that demonstrate localized or systemic reactions to the venom. As many copperhead bites can be dry (no envenomation), CroFab is not given in the absence of a reaction (such as swelling) due to the risk of complications of an allergic reaction to the treatment.[39] The antivenom can cause an immune reaction called serum sickness. Pain management, tetanus immunization, laboratory evaluation, and medical supervision in the case of complications are additional courses of action.[40] In 2002, an Illinois poison control center report on the availability of antivenom stated it used 1 Acp to 5 Acp depending on the symptoms and circumstances. Antivenom use however may not be necessary in the majority of cases, A study that analyzed 88 copperhead bite victims reported that all the victims survived and none required antivenom.[41]
This species was long considered to contain five subspecies listed below, but gene analysis suggests that A. c. laticinctus represents its own distinct species, while A. c. mokasen and A. c. phaeogaster are regional variants of A. c. contortrix, and A. c. pictigaster is a regional variant of A. c. laticinctus.[42]
Five subspecies have been recognized in the past,[8] but recent genetic analysis shows that A c. contorix and two of the subspecies are monotypic, while Agkistrodon laticinctus (formerly Agkistrodon contortrix laticinctus) and the fifth subspecies are a single distinct species.
Previous taxonomy[8][18] Current taxonomy[42] Geographic range[42] Southern copperheadAgkistrodon contortrix contortrix
(Linnaeus, 1766)
Eastern copperheadAgkistrodon contortrix
(Linnaeus, 1766)
The United States: east Texas, east Oklahoma, extreme eastern Kansas, and extreme southeastern Nebraska, eastward to the Atlantic coast; north to extreme southeast Iowa, southern Illinois, southern Indiana, southern Ohio, Pennsylvania, southeast New York, Massachusetts, and parts of Connecticut; absent from southern Georgia and the Florida Peninsula. Broad-banded copperheadAgkistrodon contortrix laticinctus
Broad-banded copperhead In the United States from eastern Kansas, southwest through central Oklahoma, central and Trans-Pecos, Texas and neighboring areas of northern Chihuahua and Coahuila, Mexico. Northern copperheadAgkistrodon contortrix mokasen
Palisot de Beauvois, 1799
Eastern copperheadAgkistrodon contortrix
The United States, in southern Illinois, extreme northeastern Mississippi, northern Alabama, northern Georgia northeast to Massachusetts, the Appalachian Mountain region and associated plateaus Osage copperheadAgkistrodon contortrix phaeogaster
Gloyd, 1969
Eastern copperheadAgkistrodon contortrix
The United States, in eastern Kansas, extreme southeastern Nebraska and a large part of Missouri Trans-Pecos copperheadAgkistrodon contortrix pictigaster
Gloyd & Conant, 1943
Broad-banded copperhead The Trans-Pecos region of western Texas and adjacent areas of northern Chihuahua and Coahuila, Mexico.Eastern copperhead, A. contortrix, at the southern limit of its range, in Liberty Co., Florida, camouflaged in dead leaves.
Eastern copperhead (Agkistrodon contortrix) from Liberty Co., Texas (30 March 2007).
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: CS1 maint: multiple names: authors list (link) {{cite journal}}
: CS1 maint: multiple names: authors list (link) The eastern copperhead (Agkistrodon contortrix), also known simply as the copperhead, is a species of venomous snake, a pit viper, endemic to eastern North America; it is a member of the subfamily Crotalinae in the family Viperidae.
The eastern copperhead has distinctive, dark brown, hourglass-shaped markings, overlaid on a light reddish brown or brown/gray background. The body type is heavy, rather than slender. Neonates are born with green or yellow tail tips, which progress to a darker brown or black within one year. Adults grow to a typical length (including tail) of 50–95 cm (20–37 in).
In most of North America, it favors deciduous forest and mixed woodlands. It may occupy rock outcroppings and ledges, but is also found in low-lying, swampy regions. During the winter, it hibernates in dens or limestone crevices, often together with timber rattlesnakes and black rat snakes. The eastern copperhead is known to feed on a wide variety of prey, including invertebrates (primarily arthropods) and vertebrates. Like most pit vipers, the eastern copperhead is generally an ambush predator; it takes up a promising position and waits for suitable prey to arrive.
As a common species within its range, it may be encountered by humans. Unlike other viperids, they often "freeze" instead of slithering away, due to its habit of relying on excellent camouflage, rather than fleeing. Bites occur due to people unknowingly stepping on or near them. Copperhead bites account for half of the treated snake bites in the United States.
Five subspecies have been recognized in the past, but recent genetic analysis had yielded new species information.