Agkistrodon laticinctus, commonly known as the broad-banded copperhead, is a venomous pit viper species,Burbrink, Frank T. and Timothy J. Guiher. 2015. Considering gene flow when using coalescent methods to delimit lineages of North American pitvipers of the genus Agkistrodon. Zoological Journal of the Linnean Society, 173: 505–526. formerly considered a subspecies of Agkistrodon contortrix, which is found in the central United States, from Kansas, through Oklahoma and throughout central Texas.
Etymology and nomenclature Agkistrodon is from the Greek words ancistro which means "hook", and odon meaning "tooth" referring to the snake's fangs.Campbell, Jonathan A. and William W. Lamar. 2004. The Venomous Reptiles of the Western Hemisphere. Vol. I & II. Comstock Publishing. Cornell University Press, Ithaca, New York. xviii, 870 pp. (Vol. I, pages 266‒270). The discrepancy between the spelling ancistro (correct) versus agkistro (incorrect), originates from a typographical error or misspelling in the original description of the genus published in 1799.Gloyd, Howard K. and Roger Conant. 1990. Snakes of the Agkistrodon Complex, A Monograph Review. Society for the Study of Amphibians and Reptiles. vi, 614 pp. (pages 105‒199). The name laticinctus is from the Latin lati meaning "broad" or "wide", and cinctus meaning a girdle, belt, or waistcloth, in reference to the broad bands of the dorsal pattern of the species, and relative to the contorted or twisted dorsal pattern of the eastern copperhead (Agkistrodon contortrix).Lewis, Charlton T. 1993 [1st ed. 1879]. A Latin Dictionary: Founded on Andrews’ Edition of Freund’s Latin Dictionary, Revised, Enlarged, and in Great Part Rewritten. Oxford University Press, Inc. Oxford. xiv, 2019 pp.
The standardized English name of Agkistrodon laticinctus is Broad-banded copperhead.Conant, Roger; Cagle, Fred R.; Goin, Coleman J.; Lowe, Charles H., Jr.; Neill, Wilfred T.; Netting, M. Graham; Schmidt, Karl P.; Shaw, Charles E.; Stebbins, Robert C.; Bogert, Charles M. (1956). "Common Names for North American Amphibians and Reptiles". Copeia 1956: 172–185.Nicholson, Kirsten E. (editor) (2025). Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding. Ninth Edition. Society for the Study of Amphibians and Reptiles. 87 pp. As the Latin name, the English name emphasizes the broad bands that readily distinguishes this species from the eastern copperhead (Agkistrodon contortrix). Colloquial names for the broad-banded copperhead include: copperhead moccasin, copperhead snake, dry-land moccasin, highland moccasin, moccasin, rattlesnake pilot, red eye, Texas copperhead and thunder snake.Wright, Albert Hazen and Anna Allen Wright. 1957. Handbook of Snakes of the United States and Canada, Vol. I & II. Comstock Publishing Associates, a division of Cornell University Press. Ithaca, New York. xviii, 1105 pp. (Vol. II, pages 903‒916)
Description
This form is typically a light tan in color, with darker brown, wide crossbands - which gives it its common name. The actual color varies, by locality, from a red-brown, to a gray-brown. It overlaps with the eastern copperhead (A. contortrix) in the southern reaches of its range, making specimens there difficult to distinguish, but generally A. contortrix has banding that narrows at the spine, creating hourglass shapes, whereas A. laticinctus has even bands. As juveniles, all species of Agkistrodon have a bright green-yellow color to their tail tips, believed to be used as a lure to attract prey items to approach within striking range. The color fades to a grey or brown at about a year of age.
Size: Adults typically range from 45‒75 cm (17.7‒29.5 in) in total body length, with a record individual of 94.6 cm (37.25 in) for the species. Agkistrodon laticinctus are sexually dimorphic, with males ranging slightly larger than females in total body length. One study measured 161 male and 119 female, adult specimens (>30 cm), and found 62.7% of the males ranged 50‒75 cm. (19.7‒29.5 in), and 76.5% of the females ranged 45‒65 cm (17.7‒25.6 in) in total body length. The same study found the tail length of males was only slightly longer than females, with tails ranging from 11‒17% (13.9) of total body length in males, and 11‒16% (13.3) in females, and Trans-Pecos populations averaging slightly longer tails, 15.3% for males and 14.6% for females. Copperheads tend to exhibit an east to west reduction in size, with the eastern copperhead (A. contortrix) averaging slightly larger in total body length than the broad-banded copperhead (A. laticinctus), and populations of A. laticinctus from Oklahoma and central Texas averaging slightly larger than those from the Trans-Pecos region and Mexico.
Scutellation: Agkistrodon laticinctus have nine large plates, symmetrically arranged on the crown of the head (two internasals, two prefrontals, one frontal, two supraoculars, two parietals): a character they share with all other species in the genus Agkistrodon, and which distinguishes Agkistrodon from the majority of pit vipers (Crotalinae), including all New World pit vipers except the genus Sistrurus (pigmy and massasauga rattlesnakes). A loreal scale is present in A. laticinctus and all other species in the genus except the cottonmouths (A. piscivorus and A. conanti). Postoculars and suboculars scales in Agkistrodon laticinctus tend to form one continuous row of 2‒6 scales, numbering 4 in about half of specimens. Supralabials range from 7‒10, numbering 8 in most specimens, and infralabials range from 8‒12, numbering 10 in most specimens. The dorsal body scales are keeled with paired apical pits. The keeling is strongest and most apparent on the vertebral scales, often becoming weaker and occasionally absent in the lateral and anterior regions. The number of midbody dorsal scale rows is typically 23 but can be 21 or 25 in a few individuals, except in populations from the Trans-Pecos region in which nearly half the specimens have 21 or 22 rows. Ventral scales: male range 138‒155, average 146.4 (Trans-Pecos populations averaging 149.3), female range138‒155, average 145.5 (Trans-Pecos average 147.3), and subcaudals: male range 42‒62 average 48 (Trans Pecos average 54), female range 40‒57 average 45 (Trans-Pecos average 50).
Distribution
The broad-banded copperhead (A. laticinctus) is endemic to North America, where it occurs in the South Central states of Oklahoma and Texas in the USA, and the adjacent margins of the Mexican states of Chihuahua and Coahuila. It ranges from north-central Oklahoma, south to the Edwards Plateau in Texas, and west into southern counties of the Trans-Pecos region of Texas, including Brewster, Jeff Davis, Pecos, Presidio, and Terrell counties. Much of its distribution (and the zone of hybridization) is situated in something of a transition zone between the Eastern Temperate Forests of the US and the Great Plains and Chihuahua Desert to the west.Powell, R, R. Conant, and J. T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, 4th ed. Houghton Mifflin Co., Boston, Massachusetts. xiii, 494 pp. (pages 435 ‒437). Werler, John E. and James R. Dixon. 2000. Texas Snakes, Identification, Distribution, and Natural History. University of Texas Press, Austin, Texas. xv, 437 pp. (pages 345‒356).
In Mexico it is known only from the states of Chihuahua and Coahuila. Copperheads were anticipated to occur in Mexico for several decades Martin del Campo, Rafael. 1935. Nota acerca de la distribución geográfica de los reptiles ponzoñosos en México. Anales del Instituto de Biología, Universidad Nacional Autónoma de México 7(2‒3): 291‒300. Smith, Hobart M. and Edward H. Taylor. 1945. An Annotated Checklist and Key to the Snakes of Mexico. Bulletin of the U. S. National Museum 187: 1‒239. (pages 177‒178). before verified records were confirmed from the remote regions south of Big Bend as recently as 1986. In Chihuahua all records are from riparian areas along the Rio Grande and adjacent canyons in the municipality of Manuel Benavides. In Coahuila it has been reported from several localities deeper in the interior including the Sierra del Burro, Sierra del Carmen, and Sierra Jardín, in the municipalities of Acuña, Müzquiz, Ocampo, and Zaragrza. Lemos Espinal, Julio A., Hobart M. Smith, James R. Dixon, and Alexander Cruz. 2015. Amphibians and Reptiles of Sonora, Chihuahua, and Coahuila, Mexico. CONABIO, Mexico D. F. 668 pp. (Vol. II, pages 415‒416, 615).
There is a wide area of integration with its sister taxon, the eastern copperhead (Agkistrodon contortrix) on the eastern and northern boundaries of its range. In one study, genetic samples from 38 copperhead specimens collected throughout its distribution in eastern Kansas, indicated all copperheads from that state were either eastern copperheads (Agkistrodon contortrix), or hybrids of eastern and broad-banded copperheads (A. contortrix x laticinctus). That study did not identify any genetically pure broad-banded copperheads (Agkistrodon laticinctus) in Kansas.
Ecology and natural history Longevity records published 1992, based on data from North American zoos, museums, and other institutions at that time included a male Agkistrodon contortrix laticinctus from the San Diego Zoo that lived 21 years, 6 month, and 9 days, and a male Agkistrodon contortrix pictigaster in the Philadelphia Zoo that lived 20 years, 8 months, and 10 days.Snider, Andrew T. and Kevin Bowler. 1992. Longevity of Reptiles and Amphibians in North American Collections, 2nd ed. Society for the Study of Amphibians and Reptiles, Herpetological Circular No. 21: iii, 40 pp. (page 33). Although not considered arboreal, Agkistrodon laticinctus is capable of climbing and has been observed coiled and resting in trees, 7 or 8 feet above the ground where no birds, nests, lizards, or other potential food was apparent.Johnson, J. E. Jr. 1948. Copperhead in a Tree. Herpetologicca 4(6): 214. Likewise, it is not an aquatic species, but it is capable of crossing large bodies of water and has been found swimming in Lake Texoma, Texas, more than a quarter of a mile from shore.Smith, Hobart M. and Ottys Sanders 1952. Distributional Data on Texan Amphibians and Reptiles. The Texas Journal of Science 4(2): 204‒219.
Habitat Secretive and nocturnal, it prefers lightly wooded habitats, typically with a good amount of ground debris for cover, not far from a permanent water source. It typically avoids regions with a significant population of humans.
Diet The diet of A. laticinctus can differ between various populations and the available prey. They are largely ambush predators, but actively forage on occasion, particularly juveniles. Odor, sight, and heat are the primary methods of locating prey. As with many species of snakes, juveniles tend to opportunistically feed on wider variety of prey, becoming more discriminating with maturity. Scavenging has been recorded in the species. Females usually fast, or eat significantly less, when gravid.Ernst, Carl. H. and Evelyn M. Ernst. 2011. Venomous Reptile of the United States, Canada, and Northern Mexico Vol. I: Heloderma, Micruroides, Micrurus, Pelamis, Agkistrodon, Sistrurus. The Johns Hopkins University Press. Baltimore, Maryland. xv, 352 pp. (pages 168‒193) Like many venomous snakes, they typically bite and release larger prey, letting the venom subdue it without the risk of a struggle and injury to the snake, but birds and smaller prey are often seized, held until dead, then swallowed. Although caudal luring is well documented in the eastern copperhead, observations of this behavior in the broad-banded copperhead are lacking.