Description:    The Cottonmouth, also known as a Water Moccasin, is a large, heavy-bodied pit viper typically measuring 24–48 in (61–122 cm) in length, though exceptionally large individuals may exceed 60 in (152 cm). The body is stout with a broad, triangular head that is distinctly wider than the neck. Heat-sensing pits are located between the eyes and nostrils and are used to detect warm-blooded prey. Cottonmouths are sexually dimorphic, with males being notably larger than females in both body size and head dimensions. Due to their larger head size, males consume different, often larger, types of prey than females.

Body coloration is variable and strongly age-dependent. Juveniles are boldly patterned with dark brown crossbands on a lighter gray, tan, or reddish background, and possess a bright yellow-green tail tip used in caudal luring, which they use to attract prey. With age, individuals darken considerably; adults are often dark olive, brown, or nearly black, with banding becoming faint or obscured altogether. The belly is typically dark with irregular lighter blotches. Scales are keeled, giving the snake a rough, matte appearance.

When threatened, cottonmouths frequently display a defensive posture that includes coiling, vibrating the tail, and opening the mouth to reveal the stark white or pinkish oral lining that gives the species its common name.

Range and Habitat:    The Cottonmouth is native to the southeastern United States, ranging from southeastern Virginia south through Florida and west through southern Alabama, Mississippi, Louisiana, eastern Texas, and portions of Arkansas and Oklahoma.

This species is strongly associated with wetlands and is commonly found in freshwater habitats, such as cypress swamps, river floodplains, heavily vegetated wetlands, and slow-moving streams. Cottonmouths may also occur in nearby upland habitats, especially during dispersal, drought conditions, or nocturnal foraging. They are frequently observed basking along banks, logs, or low vegetation near water, but seldom climb high in trees (unlike many nonvenomous watersnakes, which commonly bask on branches several feet above the water).

Habits:    Cottonmouths are primarily ambush predators but may actively forage both on land and in water. They are generally crepuscular to nocturnal during hot weather but may be active during daylight hours in cooler seasons. While often characterized as aggressive, cottonmouths typically rely on camouflage and defensive displays rather than fleeing when encountered.

This species is often confused with nonvenomous watersnakes. However, watersnakes typically flee immediately if on land or in a tree, usually going underwater. In contrast, cottonmouths frequently stand their ground and gape to deter a predator. Despite their aggressive reputation, research indicates that cottonmouths rarely bite unless stepped on or picked up.

Diet is broad and opportunistic, consisting of fish, frogs, salamanders, small turtles, snakes, birds, and mammals. They readily scavenge carrion and have been documented feeding on injured or dead prey, a behavior relatively uncommon among snakes.

Cottonmouths become reproductively active within two to three years. Courtship and mating may occur during both spring and autumn. Females give birth in late summer to early fall, typically delivering litters of 3-15 young each measuring approximately 7–10 in (18–25 cm) at birth. Prior to giving birth, females are sometimes found in small groups, and some may remain near their newborns for a short period after birth, possibly reducing predation risk. Because of the high energetic cost of reproduction, cottonmouths, like many viper species, often do not reproduce every year.

Ecologically, cottonmouths serve as important mesopredators in wetland systems, helping regulate populations of aquatic and semi-aquatic vertebrates. They are preyed upon by large birds of prey, alligators, and other snakes, including kingsnakes.

Venom and Bites:    Cottonmouth venom is primarily hemotoxic, causing tissue destruction, pain, swelling, and disruption of normal blood clotting. Components of the venom damage blood vessels, break down red blood cells, and may lead to localized necrosis. Envenomation can also result in nausea, hypotension, and secondary infection if untreated.

Although cottonmouth bites can be medically serious, fatalities are rare with prompt access to modern antivenin and supportive care. Most bites occur when individuals attempt to handle, kill, or intentionally harass the snake.

Any suspected cottonmouth bite should be treated as a medical emergency. Immediate transport to a medical facility capable of administering antivenin is essential.

First Aid Protocol:    Move away from the snake and call emergency services immediately. Keep the victim calm and limit movement to slow venom spread. Immobilize the affected limb at or slightly below heart level and remove jewelry or tight clothing before swelling occurs. Do not apply tourniquets, attempt to cut or suck the wound, or use ice or electric shock.

Conservation Status:    The Cottonmouth is currently listed as Least Concern by the IUCN due to its wide distribution and adaptability. However, localized declines have been documented in parts of its range due to wetland loss, road mortality, and deliberate human killing driven by fear and misidentification.

In Georgia, cottonmouths are not afforded special legal protection but play a vital ecological role in wetland ecosystems. Public education and habitat conservation remain key to reducing unnecessary persecution.

Pertinent References:

• DeVault, T. L., & Krochmal, A. R. (2002). Scavenging by Snakes: An Examination of the Literature. Herpetologica, 58(4), 429–436.
• Glaudas, X., & Winne, C. T. (2007). Do warning displays predict striking behavior in a viperid snake, the cottonmouth (Agkistrodon piscivorus)? Canadian Journal of Zoology, 85(4), 574–578.
• Glaudas, X., Winne, C. T., & Fedewa, L. A. (2006). Ontogeny of Anti-Predator Behavioral Habituation in Cottonmouths (Agkistrodon piscivorus). Ethology, 112(6), 608–615.
• Vincent, S. E., Herrel, A., & Irschick, D. J. (2004). Sexual Dimorphism in Head Shape and Diet in the Cottonmouth Snake ( Agkistrodon piscivorus ). Journal of Zoology, 264(1), 53–59. https://doi.org/10.1017/s0952836904005503