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The eastern copperhead (''Agkistrodon contortrix''), also known simply as the copperhead, is a widespread
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
venomous snake ''Venomous snakes'' are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow ...
, a
pit viper The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or pit adders, are a subfamily (biology), subfamily of Viperidae, vipers found in Asia and the ...
,
endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to eastern North America; it is a member of the
subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...
Crotalinae The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or pit adders, are a subfamily of vipers found in Asia and the Americas. Like all other vipers ...
in the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Viperidae Vipers are snakes in the family Viperidae, found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, New Zealand, Ireland, and various other isolated islands. They are venomous snake, venomous and have long (relat ...
. 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 . In most of North America, the eastern copperhead favors
deciduous forest In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flo ...
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 rattlesnake The timber rattlesnake (''Crotalus horridus''), also known Common name, commonly as the canebrake rattlesnake and the banded rattlesnake,Albert Hazen WWright AH, species:Anna Allen WWright AA (1957). ''Handbook of Snakes of the United States a ...
s and black rat snakes. The eastern copperhead is known to feed on a wide variety of prey, including
invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...
(primarily
arthropods Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
) and
vertebrates Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...
. 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, it often "freezes" instead of slithering away and fleeing, due to its habit of relying on excellent camouflage. Bites occur due to people unknowingly stepping on or near them.Venomous Snakes
. National Institute for Occupational Safety and Health. Retrieved on November 10, 2008.
Copperhead bites account for half of the treated snake bites in the United States. Five
subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
have been recognized in the past, but recent genetic analysis has yielded new species information.


Etymology

Its generic name is derived from the
Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...
words ''ankistron'' "hook, fishhook" and ''odon'', variant of ''odous'' "tooth". The
trivial name In chemistry, a trivial name is a non-systematic name for a chemical substance. That is, the name is not recognized according to the rules of any formal system of chemical nomenclature such as IUPAC inorganic or IUPAC organic nomenclature. A ...
, or
specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
, 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.Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publishing Associates. .


Description

Adults grow to a typical length (including tail) of . Some may exceed , although that is exceptional for this species. Males do not typically exceed and weigh from , with a mean of roughly . Females do not typically exceed , and have a mean body mass of . The maximum length reported for this species is for '' A. c. mokasen'' (Ditmars, 1931). Brimley (1944) mentions a specimen of ''A. c. mokasen'' from
Chapel Hill, North Carolina Chapel Hill is a town in Orange County, North Carolina, Orange and Durham County, North Carolina, Durham counties, North Carolina, United States. Its population was 61,960 in the 2020 United States census, making Chapel Hill the List of municipa ...
, that was "four feet, six inches" (137.2 cm), but this may have been an approximation. The maximum length for ''A. c. contortrix'' is (Conant, 1958). 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. Gloyd HK, Conant R (1990). ''Snakes of the'' Agkistrodon ''Complex: A Monographic Review''. Society for the Study of Amphibians and Reptiles. LCCN 89-50342. . The escalation includes 21–25 (usually 23) rows of
dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...
at midbody, 138–157
ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that cont ...
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 In reptiles, the supralabial scales, also called upper-labials, are those scales that border the mouth opening along the upper jaw. They do not include the median scaleWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates ( ...
, and 8–13 (usually 10)
sublabial scales In reptiles, the sublabial scales, also called lower-labials or infralabials, are those scales that border the mouth opening along the lower jaw. They do not include the median scaleWright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publis ...
. 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. 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 Terrebonne Parish ( ; French: ''Paroisse de Terrebonne'') is a parish located in the southern part of the U.S. state of Louisiana. At the 2020 census, the population was 109,580. The parish seat is Houma. The parish was founded in 1822. Ter ...
had a similar striped pattern, with only the first and last two crossbands being normal.


Distribution and habitat

The eastern copperhead is found in North America; its range within the United States is in
Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...
,
Arkansas Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...
,
Connecticut Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. ...
,
Delaware Delaware ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic and South Atlantic states, South Atlantic regions of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey ...
,
District of Columbia Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...
,
Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
,
Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...
,
Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...
,
Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...
,
Iowa Iowa ( ) is a U.S. state, state in the upper Midwestern United States, Midwestern region of the United States. It borders the Mississippi River to the east and the Missouri River and Big Sioux River to the west; Wisconsin to the northeast, Ill ...
,
Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...
,
Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...
,
Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...
,
Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...
,
Massachusetts Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode ...
,
Mississippi Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...
,
Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...
,
Nebraska Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...
,
New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...
, New York,
North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...
,
Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...
,
Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...
,
Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...
,
South Carolina South Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia (U.S. state), Georg ...
,
Tennessee Tennessee (, ), officially the State of Tennessee, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Kentucky to the north, Virginia to the northeast, North Carolina t ...
,
Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
,
Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...
, and
West Virginia West Virginia is a mountainous U.S. state, state in the Southern United States, Southern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States.The United States Census Bureau, Census Bureau and the Association of American ...
. In
Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
, it occurs in Chihuahua and
Coahuila Coahuila, formally Coahuila de Zaragoza, officially the Free and Sovereign State of Coahuila de Zaragoza, is one of the 31 states of Mexico. The largest city and State Capital is the city of Saltillo; the second largest is Torreón and the thi ...
. The type locality is "Carolina". Schmidt (1953) proposed the type locality be restricted to "Charleston, South Carolina". McDiarmid RW, Campbell JA, Touré TA (1999). ''Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1''. Washington, District of Columbia: Herpetologists' League. (series). (volume). Unlike some other
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of North American pit vipers, such as the
timber rattlesnake The timber rattlesnake (''Crotalus horridus''), also known Common name, commonly as the canebrake rattlesnake and the banded rattlesnake,Albert Hazen WWright AH, species:Anna Allen WWright AA (1957). ''Handbook of Snakes of the United States a ...
and massasauga, the copperhead has mostly not re-established itself north of the
terminal moraine A terminal moraine, also called an end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front e ...
after the last glacial period (the
Wisconsin glaciation The Wisconsin glaciation, also called the Wisconsin glacial episode, was the most recent glacial period of the North American ice sheet complex, peaking more than 20,000 years ago. This advance included the Cordilleran Ice Sheet, which nucleated ...
), though it is found in southeastern New York and southern
New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...
, north of the Wisconsin glaciation terminal moraine on
Long Island Long Island is a densely populated continental island in southeastern New York (state), New York state, extending into the Atlantic Ocean. It constitutes a significant share of the New York metropolitan area in both population and land are ...
. Eastern copperheads are habitat generalists which are species able to survive in different habitats (fragmented and unfragmented). Within its range, it occupies a variety of different habitats. In most of North America, it favors
deciduous forest In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flo ...
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. In the states around the
Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...
, however, this species is also found in
coniferous forest Conifers () are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All e ...
. In the Chihuahuan Desert of
West Texas West Texas is a loosely defined region in the U.S. state of Texas, generally encompassing the desert climate, arid and semiarid climate, semiarid lands west of a line drawn between the cities of Wichita Falls, Texas, Wichita Falls, Abilene, Texa ...
and northern Mexico, it occurs in riparian habitats, usually near permanent or semipermanent water and sometimes in dry arroyos (brooks). Habitat fragmentation has been found to impair Eastern Copperhead access to feeding, brumation, and reproduction sites.


Conservation status

This species is classified as least concern on the
IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...
Red List of Threatened Species (v3.1, 2001). 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. Their venom has potential medicinal value to humans.


Behavior

In the
Southern United States The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, Dixieland, or simply the South) is List of regions of the United States, census regions defined by the United States Cens ...
, 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. 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. Generally nonaggressive, will only strike if threatened as a last resort. 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.


Diet and feeding behavior

The eastern copperhead is a diet generalist and is known to feed on a wide variety of prey, including
invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...
(primarily
arthropods Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
) and
vertebrates Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...
. A generalized
ontogenetic Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the stu ...
shift in the diet occurs, with juveniles feeding on higher percentages of invertebrates and ectotherms, and adults feeding on a higher percentage vertebrate
endotherms An endotherm (from Ancient Greek, Greek ἔνδον ''endon'' "within" and θέρμη ''thermē'' "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily ...
. Both juveniles and adults, though, feed on invertebrates and vertebrates opportunistically. The diet is also known to vary among geographic populations.Ernst, Carl H. and Evelyn M. Ernst. (2011). ''Venomous Reptiles of the United States, Canada, and Northern Mexico'', Volume 1. The Johns Hopkins University Press. Baltimore, Maryland. Studies conducted at various locations within the range of the eastern copperhead (''A. contortrix''), including Tennessee,
Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...
,
Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...
, and
Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
, identified some consistently significant prey items included cicadas ('' Tibicen''), caterpillars (
Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...
), lizards ('' Sceloporus'' and '' Scincella''), voles (''
Microtus ''Microtus'' is a genus of voles found in North America, Europe and northern Asia. The genus name refers to the small ears of these animals. They are stout rodents with short ears, legs and tails. They eat green vegetation such as grasses and se ...
''), and mice (''
Peromyscus ''Peromyscus'' is a genus of rodents. They are commonly referred to as deer mice or deermice, not to be confused with the chevrotain or "mouse deer". They are New World mice only distantly related to the common house and laboratory mouse, ''M ...
''). 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. Werler, John E. and James R. Dixon. (2000). ''Texas Snakes: Identification, Distribution, and Natural History''. Austin, Texas: University of Texas Press. Other items documented in the diet include various invertebrates, e.g. millipedes (
Diplopoda Millipedes (originating from the Latin , "thousand", and , "foot") are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derive ...
), spiders (
Arachnida Arachnids are arthropods in the class Arachnida () of the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons. Adult arachnids ...
), beetles (
Coleoptera Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...
), dragonflies (
Odonata Odonata is an order of predatory flying insects that includes the dragonflies and damselflies (as well as the '' Epiophlebia'' damsel-dragonflies). The two major groups are distinguished with dragonflies (Anisoptera) usually being bulkier with ...
), grasshoppers (
Orthoptera Orthoptera () is an order of insects that comprises the grasshoppers, locusts, and crickets, including closely related insects, such as the bush crickets or katydids and wētā. The order is subdivided into two suborders: Caelifera – gras ...
), and mantids (
Mantidae Mantidae is one of the largest family (biology), families in the Order (biology), order of Mantodea, praying mantises, based on the type species ''Mantis religiosa''; most genera are tropical or subtropical. Historically, this was the only family ...
), 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. 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. They possess facial pit organs which is a complex infrared-imaging system that allows accurate and precise strikes on potential prey. Juveniles use a brightly colored tail to attract frogs and perhaps lizards, a behavior termed caudal luring (see video

. 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. wiktionary:gravid, Gravid females typically fast, although some individuals occasionally take small volumes of food. 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. Predators of the eastern copperhead are not well known, but may include owls, hawks, opossums, bullfrogs, and other snakes. They will use anti-predatory behaviors to discourage predators. These include: move away or flee, musking, tail vibrating, mouth gaping, or curling up into a camouflage pile.


Reproduction

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. Mating is sometimes preceded by male combat. In male combat, losing experience had a greater effect than SVL in winning access to females. Females give birth to live young, each of which is about in total length. The typical litter size is four to seven, but as few as one, or as many as 20 may be seen. Females are capable of storing sperm for up to a year. 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.


Facultative parthenogenesis

Parthenogenesis Parthenogenesis (; from the Greek + ) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means the development of an embryo from an unfertiliz ...
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. 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 Inbreeding depression is the reduced biological fitness caused by loss of genetic diversity as a consequence of inbreeding, the breeding of individuals closely related genetically. This loss of genetic diversity results from small population siz ...
). Both captive-born and wild-born ''A. contortrix'' snakes appear to be capable of this form of parthenogenesis.


Venom

Although venomous, eastern copperheads are generally not aggressive and bites are rarely fatal. 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. 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. The fangs of dead pit vipers are capable of delivering venom in amounts that necessitate the use of antivenom. 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. The venom of the southern copperhead has been found to hold the protein ''contortrostatin'' that halts the growth of cancer cells in mice and also stops the migration of the tumors to other sites. However, this is an
animal model An animal model (short for animal disease model) is a living, non-human, often genetic-engineered animal used during the research and investigation of human disease, for the purpose of better understanding the disease process without the risk of ha ...
, and further testing is required to verify safety and efficacy in humans. The
antivenom Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if ...
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. The antivenom can cause an immune reaction called
serum sickness Serum sickness in humans is a adverse drug reaction, reaction to proteins in antiserum derived from a non-human animal source, occurring 5–10 days after exposure. Symptoms often include a rash, Arthralgia, joint pain, fever, and lymphadenopathy. ...
.
Pain management Pain management is an aspect of medicine and health care involving relief of pain (pain relief, analgesia, pain control) in various dimensions, from acute (medicine), acute and simple to chronic condition, chronic and challenging. Most physici ...
, tetanus immunization, laboratory evaluation, and medical supervision in the case of complications are additional courses of action. 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.


Subspecies

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''. Five
subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
have been recognized in the past, 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.


Gallery

File:Kupferkopf-02.jpg, Head of copperhead photographed in Rheinberger Terra-Zoo, Germany. Image:CopperheadInLeavesCU.JPG, Eastern copperhead, ''A. contortrix'', at the southern limit of its range, in Liberty Co., Florida, camouflaged in dead leaves. File:Copperhead (Agkistrodon contortrix) photographed in Liberty Co., Texas. W. L. Farr.jpg, Eastern copperhead (''Agkistrodon contortrix'') from Liberty Co., Texas (30 March 2007). File:Eastern copperhead - Agkistrodon contortrix (42669143530).jpg, A copperhead from Jefferson Co., Missouri with yellow tail typical of juveniles (2 Sept. 2018). File:Southern Copperhead.JPG, Eastern copperhead (''Agkistrodon contortrix'') from Georgetown Co., South Carolina (23 August 2013). File:Osage Copperhead (Agkistrodon contortrix phaeogaster) (16426738014).jpg, Eastern copperhead (''Agkistrodon contortrix'') Jefferson Co., Missouri (5 April 2015: 67 °F) were previously classified as "Osage copperhead" (''Agkistrodon contortrix phaeogaster''). File:Nördlicher Kupferkopf.JPG, Eastern copperhead (''Agkistrodon contortrix'') Westchester County, New York (May 2002). Northern populations, typically darker, were previously classified as ''A. c. mokasen''. File:Agkistrodon contortrix-DS-2.JPG, View of the ventral, or belly, pattern of a copperhead.


References


Further reading

* Behler JL, King FW (1979). ''The Audubon Society Field Guide to North American Reptiles and Amphibians''. New York: Alfred A. Knopf. . (''Agkistrodon contortrix'', pp. 683–684 + Plates 649–652, 655). * Boulenger GA (1896). ''Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the ... Viperidæ.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I-XXV. (''Ancistrodon contortrix'', pp. 522–523). * Conant R (1975). ''A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition''. Boston: Houghton Mifflin. xviii + 429 pp. + Plates 1-48. (hardcover), (paperback). (''Agkistrodon contortrix'', pp. 226–228 + Plate 34 + Map 174). *Conant R, Bridges W (1939). ''What Snake Is That?: A Field Guide to the Snakes of the United States East of the Rocky Mountains''. (with 108 drawings by Edmond Malnate). New York and London: D. Appleton-Century. Frontispiece map + viii + 163 pp. + Plates A-C, 1-32. (''Agkistrodon mokasen'', pp. 136–139 + Plate 27, Figures 79–81). * Gloyd HK (1934). "Studies on the Breeding Habits and Young of the Copperhead, ''Agkistrodon mokasen'' Beauvois". ''Papers Michigan Acad. Sci.'' 19: 587–604, 2 figures, 3 plates. * Holbrook JE (1838). ''North American Herpetology; or, A Description of the Reptiles Inhabiting the United States'' irst edition ''Vol II.'' Philadelphia: J. Dobson. (E.G. Dorsey, printer). 130 pp. + Plates I-XXX. (''Trigonocephalus contortrix'', pp. 69–72 + Plate XIV). *Holbrook JE (1842). ''North American Herpetology; or, A Description of the Reptiles Inhabiting the United States'' econd edition ''Vol. III.'' Philadelphia: J. Dobson. (E.G. Dorsey, printer). 128 pp. + Plates I-XXX. (''Trigonocephalus contortrix'', pp. 39–42 + Plate VIII). * Hubbs B, O'Connor B (2012). ''A Guide to the Rattlesnakes and other Venomous Serpents of the United States''. Tempe, Arizona: Tricolor Books. 129 pp. . (''Agkistrodon contortrix'', pp. 93–103). * Jan G, Sordelli F (1874). ''Iconographie générale des Ophidiens, Quarante-sixième livraison''. Paris: Baillière. Index + Plates I-VI. (''Trigonocephalus contortrix'', Plate V, Figure 1). (in French). * Linnaeus C (1766). ''Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio Duodecima, Reformata.'' Stockholm: L. Salvius. 532 pp. (''Boa contortrix'', new species, p. 373). (in
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
). * * Morris PA (1948). ''Boy's Book of Snakes: How to Recognize and Understand Them''. A volume of the Humanizing Science Series, edited by Jaques Cattell. New York: Ronald Press. viii + 185 pp. (''Agkistrodon contortrix'', pp. 110–114, 181). * Powell R, Conant R, Collins JT (2016). ''Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition''. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 207 Figures, 47 color plates. . (''Agkistrodon contortrix'', pp. 436–437, Figure 197 + Plate 45). * Schmidt KP, Davis DD (1941). ''Field Book of Snakes of the United States and Canada''. New York: G.P. Putnam's Sons. 365 pp. (''Agkistrodon mokasen'', pp. 283–285 + Plate 30). * Smith HM, Brodie ED Jr (1982). ''Reptiles of North America: A Guide to Field Identification''. New York: Golden Press. 240 pp. ("limp"), (hardcover). (''Agkistrodon contortrix'', pp. 198–199). * Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates. 1,105 pp. (in two volumes). (''Ancistrodon contortrix'', pp. 903–916 + Figures 259, 261–263 + Map 64). * Zim HS, Smith HM (1956). ''Reptiles and Amphibians: A Guide to Familiar American Species: A Golden Nature Guide''. New York: Simon and Schuster. 160 pp. (''Ancistrodon contortrix'', pp. 109, 156).


External links

*
Copperhead
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