The eastern copperhead (''Agkistrodon contortrix''), also known as the copperhead, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
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 or g ...
, a
pit viper,
endemic
Endemism is the state of a species being found 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 found else ...
to eastern North America; it is a member of the
subfamily Crotalinae
The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . crotaline snakes (from grc, κρόταλον ''krotalon'' castanet), or pit adders, are a subfa ...
in the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Viperidae
The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs th ...
.
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, 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, ...
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 snake Black rat snake may refer to:
*'' Pantherophis alleghaniensis'', the eastern ratsnake
* '' Pantherophis spiloides'', the central ratsnake
*''Pantherophis obsoletus
''Pantherophis obsoletus'', also known commonly as the western rat snake, black ...
s.
The eastern copperhead is known to feed on a wide variety of prey, including
invertebrates
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordat ...
(primarily
arthropods) and
vertebrates
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...
. 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.
[Allf BC, Durst PA, Pfennig DW (2016). "Behavioral plasticity and the origins of novelty: the evolution of the rattlesnake rattle". ''The American Naturalist'' 188 (4): 475-483.] 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.
Five
subspecies have been recognized in the past,
but recent genetic analysis had yielded new species information.
Etymology
Its
generic name is derived from the
Greek
Greek may refer to:
Greece
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 ...
words ''ancistro'' (hooked) and ''odon'' (tooth), or fishhook. 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, 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, 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
In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down t ...
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, and 8–13 (usually 10)
sublabial scales.
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
In zoology, intergradation is the way in which two distinct subspecies are connected via areas where populations are found that have the characteristics of both. There are two types of intergradation: primary and secondary intergradation.
Primary ...
with it, have also been reported. In a specimen described by Livezey (1949) from
Walker County, Texas
Walker County is a county located in the east central section of the U.S. state of Texas. As of the 2020 census, its population was 76,400. Its county seat is Huntsville. Initially, Walker County was named for Robert J. Walker, a legislator f ...
, 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
Lowndes County is in the central part of the U.S. state of Alabama. As of the 2020 census, the county's population was 10,311. Its county seat is Hayneville. The county is named in honor of William Lowndes, a member of the United States Con ...
, 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 2010 census, the population was 111,860, and 110,461 in 2019. In 2020, its population declined to 109,58 ...
, by Ernest A. Liner, had a similar striped pattern, with only the first and last two crossbands being normal.
Distribution and habitat
Eastern copperheads found in North America; its range within the United States is in
Alabama
(We dare defend our rights)
, anthem = "Alabama"
, image_map = Alabama in United States.svg
, seat = Montgomery
, LargestCity = Huntsville
, LargestCounty = Baldwin County
, LargestMetro = Greater Birmingham
, area_total_km2 = 135,765 ...
,
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the O ...
,
Connecticut
Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its capita ...
,
Delaware
Delaware ( ) is a state in the Mid-Atlantic region of the United States, bordering Maryland to its south and west; Pennsylvania to its north; and New Jersey and the Atlantic Ocean to its east. The state takes its name from the adjacent Del ...
,
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
,
Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
,
Illinois
Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rockf ...
,
Indiana
Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...
,
Iowa
Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to th ...
,
Kansas
Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to th ...
,
Kentucky
Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia ...
,
Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
,
Maryland
Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...
,
Massachusetts
Massachusetts (Massachusett: ''Muhsachuweesut Massachusett_writing_systems.html" ;"title="nowiki/> məhswatʃəwiːsət.html" ;"title="Massachusett writing systems">məhswatʃəwiːsət">Massachusett writing systems">məhswatʃəwiːsət'' En ...
,
Mississippi
Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
,
Missouri
Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas t ...
,
Nebraska
Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the sout ...
,
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
,
New York,
North Carolina
North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and ...
,
Ohio
Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...
,
Oklahoma,
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
,
South Carolina
)'' Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no)
, anthem = " Carolina";" South Carolina On My Mind"
, Former = Province of South Carolina
, seat = Columbia
, LargestCity = Charleston
, LargestMetro = ...
,
Tennessee
Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
,
Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
,
Virginia
Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...
, and
West Virginia
West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the B ...
. In
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, it occurs in
Chihuahua and
Coahuila. 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
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of North American pit vipers, such as the
timber rattlesnake
The timber rattlesnake, canebrake rattlesnake, or banded rattlesnake (''Crotalus horridus'') Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates, a division of ...
and
massasauga
The massasauga (''Sistrurus catenatus'') is a rattlesnake species found in midwestern North America from southern Ontario to northern Mexico and parts of the United States in between. Like all rattlesnakes, it is a pit viper and is venomous.
Th ...
, the copperhead has mostly not re-established itself north of the
terminal moraine
A terminal moraine, also called 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 edge ...
after the
last glacial period (the
Wisconsin glaciation
The Wisconsin Glacial Episode, also called the Wisconsin glaciation, was the most recent glacial period of the North American ice sheet complex. This advance included the Cordilleran Ice Sheet, which nucleated in the northern North American Cord ...
), though it is found in southeastern New York and southern
New England
New England is a region comprising 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 Can ...
, 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
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, ...
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 snake Black rat snake may refer to:
*'' Pantherophis alleghaniensis'', the eastern ratsnake
* '' Pantherophis spiloides'', the central ratsnake
*''Pantherophis obsoletus
''Pantherophis obsoletus'', also known commonly as the western rat snake, black ...
s.
In the states around the
Gulf of Mexico
The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...
, 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 exta ...
. In the
Chihuahuan Desert
The Chihuahuan Desert ( es, Desierto de Chihuahua, ) is a desert ecoregion designation covering parts of northern Mexico and the southwestern United States. It occupies much of far West Texas, the middle to lower Rio Grande Valley and the lo ...
of
West Texas
West Texas is a loosely defined region in the U.S. state of Texas, generally encompassing the arid and semiarid lands west of a line drawn between the cities of Wichita Falls, Abilene, and Del Rio.
No consensus exists on the boundary betwee ...
and northern Mexico, it occurs in
riparian habitats, usually near permanent or semipermanent water and sometimes in dry
arroyos (brooks).
Conservation status
This species is classified as least concern on the
IUCN Red List of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...
(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.
Behavior
In the
Southern United States
The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, or simply the South) is a geographic and cultural region of the United States of America. It is between the Atlantic Ocean ...
, 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. Like most other New World vipers, copperheads exhibit defensive
tail vibration Tail vibration is a common behavior in some snakes where the tail is vibrated rapidly as a defensive response to a potential predator. Tail vibration should not be confused with where the tail is twitched in order to attract prey. While rattlesnakes ...
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 a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordat ...
(primarily arthropods) and vertebrates
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...
. 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 st ...
shift in the diet occurs, with juveniles feeding on higher percentages of invertebrates and ectotherms
An ectotherm (from the Greek () "outside" and () "heat") is an organism in which internal physiological sources of heat are of relatively small or of quite negligible importance in controlling body temperature.Davenport, John. Animal Life a ...
, and adults feeding on a higher percentage vertebrate endotherms
An endotherm (from 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 functions inste ...
. 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 state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia ...
, Kansas
Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to th ...
, and Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
, identified some consistently significant prey items included cicadas ('' Tibicen''), caterpillars ( Lepidoptera), 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. About 62 species are placed in the genus. They are stout rodents with short ears, legs and tails. They ea ...
''), 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, ''Mu ...
''). 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 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 derived from this feature. Each double-legged segment is a resu ...
), spiders ( Arachnida), beetles ( Coleoptera), dragonflies (Odonata
Odonata is an order of flying insects that includes the dragonflies and damselflies. Members of the group first appeared during the Triassic, though members of their total group, Odonatoptera, first appeared in Late Carboniferous.
The two com ...
), grasshoppers ( Orthoptera), and mantids (Mantidae
Mantidae is one of the largest families in the order of praying mantises, based on the type species '' Mantis religiosa''; however, most genera are tropical or subtropical. Historically, this was the only family in the order, and many references ...
), 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. 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.
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. They 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. 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 grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and developmen ...
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
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism.
...
, expression of deleterious recessive alleles, and often to developmental failure (inbreeding depression
Inbreeding depression is the reduced biological fitness which has the potential to result from inbreeding (the breeding of related individuals). Biological fitness refers to an organism's ability to survive and perpetuate its genetic material. ...
). 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
''Agkistrodon piscivorus'' is a species of pit viper in the subfamily Crotalinae of the family Viperidae. It is one of the world's few semiaquatic vipers (along with the Florida cottonmouth), and is native to the southeastern United States. As ...
. 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. Pit vipers that are dead are still dangerous and capable of producing 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 a protein called "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 th ...
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 reaction to proteins in antiserum derived from a non-human animal source, occurring 5–10 days after exposure. Symptoms often include a rash, joint pain, fever, and lymphadenopathy. It is a type of hypersensitivity ...
. 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 and simple to chronic and challenging. Most physicians and other health professionals pr ...
, 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.
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 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
An infrared search and track (IRST) system (sometimes known as infrared sighting and tracking) is a method for detecting and tracking objects which give off infrared radiation, such as the infrared signatures of jet aircraft and helicopters.
...
''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, diferentiis, 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 branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
).
*
* 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 Jaques (Jack) Cattell (2 June 1904 in Garrison, New York – 19 December 1961) was an American publisher and founder of a company bearing his name, "Jaques Cattell Press, Inc.," based in Lancaster, Pennsylvania.
Jaques Cattell Press, Inc. The Sc ...
. 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
on Reptiles and Amphibians of Iowa
{{Taxonbar, from=Q1248772
contortrix
Fauna of the Southeastern United States
Reptiles of the United States
Venomous snakes
Articles containing video clips
Taxa named by Carl Linnaeus
Reptiles described in 1766