Copperheads and water moccasins, also known as cottonmouths, are often confused due to shared characteristics and overlapping habitats. While these two species share superficial similarities, they possess distinct features that set them apart. This article clarifies the differences between copperheads and water moccasins, providing information to help identify each snake.
Two Distinct Species
Copperheads and water moccasins are separate species, though both belong to the pit viper subfamily (Crotalinae) within the viper family (Viperidae). The copperhead’s scientific name is Agkistrodon contortrix, while the water moccasin is Agkistrodon piscivorus. These scientific classifications highlight their biological separation, despite their shared evolutionary lineage as pit vipers.
Both species are native to eastern North America, with ranges that can overlap in various regions of the southeastern United States. This geographical overlap contributes to frequent misidentification.
Key Identifying Features
Distinguishing between copperheads and water moccasins involves observing several key characteristics related to their appearance, preferred habitats, and typical behaviors. While both are venomous pit vipers, their individual traits offer reliable clues for identification. Always maintain a safe distance when attempting to identify any snake.
Copperheads typically display a light reddish-brown, tan, or pinkish background color, overlaid with distinctive dark brown, hourglass-shaped crossbands that are wider on the sides and narrower across the back. Their heads are often unmarked and coppery in color, which gives them their common name. Juvenile copperheads possess a bright yellow or sulfur-colored tail tip, which they use to lure prey.
Water moccasins, by contrast, tend to be darker, with colors ranging from dark brown or black to olive, sometimes with faint brown or black crossbands that can become less distinct with age, often appearing uniformly dark in older adults. Their heads are notably broad and blocky, appearing wider than their necks due to large venom glands. When threatened, water moccasins often open their mouths wide to reveal a stark white interior, earning them the nickname “cottonmouth.”
Regarding habitat, copperheads are more terrestrial, favoring upland forests, rocky outcrops, wooded hillsides, and even suburban areas. They can be found near water but generally prefer drier environments. Water moccasins are semi-aquatic and are almost always found in or near water, inhabiting swamps, marshes, ponds, lakes, streams, and even brackish water. They are capable swimmers and can sometimes be seen basking on logs or branches near water.
Behaviorally, copperheads are often described as less aggressive; they tend to freeze and rely on their camouflage when threatened, which can unfortunately lead to accidental encounters if someone steps too close. Water moccasins, however, are known for their defensive display of coiling and showing the white lining of their mouth when confronted, and they may stand their ground rather than flee. Both snakes are primarily nocturnal during warmer months but can be active during the day in cooler temperatures.
Shared Traits and Misconceptions
The frequent confusion between copperheads and water moccasins stems from several shared characteristics, particularly their classification within the pit viper family. Both species possess heat-sensing pits located between their eyes and nostrils, which allow them to detect warm-blooded prey. Their heads are also distinctly triangular, a common trait among pit vipers due to the presence of venom glands. Additionally, both have vertical, elliptical pupils, similar to a cat’s eye.
Their geographical ranges overlap significantly across the southeastern United States, increasing the likelihood of encountering both species in the same general area. For instance, both can be found in states like Georgia, Alabama, and parts of Texas. This overlap means that a snake seen in a particular region could potentially be either a copperhead or a water moccasin, contributing to misidentification.
Superficial similarities in appearance also contribute to the confusion. Both snakes have robust bodies and can exhibit brown or dark coloration, especially adult water moccasins which can appear uniformly dark. Juvenile water moccasins may even display banded patterns and a somewhat “copper-ish” coloration, leading them to be mistaken for copperheads.
Misconceptions about their aggression also play a role. While water moccasins have a reputation for being aggressive, neither species typically attacks unless provoked. Their defensive behaviors, such as the “cottonmouth” display, are warnings intended to deter threats. Despite these shared traits and misunderstandings, careful observation of their distinct patterns, habitats, and behaviors can help differentiate these two venomous snakes.