Cottonmouth snakes, scientifically known as Agkistrodon piscivorus, are semi-aquatic pit vipers native to the southeastern United States. These venomous reptiles are well-adapted to life both in and around water. Understanding their preferred habitats and geographical range is important for recognizing these unique animals.
Geographical Distribution
Cottonmouths are widely distributed across the southeastern United States, from southern Virginia to the Florida peninsula. Their range extends westward through Alabama, Mississippi, and Louisiana, reaching central Texas. These snakes also inhabit Arkansas, Oklahoma, and extend northward up the Mississippi River valley into southern Illinois and southern Missouri.
While their overall range is extensive, cottonmouth presence can be localized. For instance, in South Carolina, they are primarily found in the sandhills and coastal plain regions, generally avoiding the piedmont and mountain areas. Similarly, in North Carolina, they are predominantly found in the Coastal Plain and some parts of the Outer Banks.
Preferred Habitats
Cottonmouths display a strong preference for aquatic and semi-aquatic environments. They are commonly found in a variety of freshwater habitats, including swamps, marshes, bogs, and the edges of ponds and lakes. Their affinity for water also extends to slow-moving rivers, streams, sloughs, and drainage ditches.
These snakes frequently utilize features within these watery landscapes such as dense vegetation, fallen logs, and rocks. They are often observed basking on banks or overhanging branches near water bodies, allowing them to regulate body temperature and remain close to prey. Cottonmouths are not strictly confined to water, as they can travel overland and have been found more than a mile from a water source. They adapt to less moist environments like pine flatwoods or riparian forests and can also inhabit brackish waters and salt marshes.
Recognizing Cottonmouths in Their Environment
Identifying cottonmouths in their natural setting involves observing several distinct physical and behavioral characteristics. These snakes possess a stocky, heavy body that typically ranges from olive, brown, to black coloration. Adults often have obscure or absent crossbands, while juveniles may display more distinct reddish-brown patterns with a sulfur-yellow tail tip. Their head is broad and triangular, distinctly wider than their neck, and features a dark stripe that runs through the eye.
A key identification feature is the white, cotton-like lining of their mouth, which they often display when feeling threatened. Unlike many non-venomous water snakes, cottonmouths tend to swim with their head and a significant portion of their body held above the water’s surface. Additionally, they possess vertical, cat-like pupils and heat-sensing facial pits located between their eyes and nostrils.