Water moccasins, also known as cottonmouths, are not native to California. These venomous snakes are found exclusively in the southeastern United States. Misidentification often occurs due to their similar appearance to native California snake species or shared aquatic habitats.
Where Water Moccasins Are Found
Water moccasins (scientific name Agkistrodon piscivorus) are venomous snakes predominantly found in the southeastern United States. Their natural habitat extends from southeastern Virginia, south through Florida, and west to central Texas and southern Oklahoma. These snakes are semiaquatic, thriving in various wetland environments such as swamps, marshes, ditches, ponds, lakes, and streams. While they are highly adapted to aquatic life, they can also be found on land, sometimes wandering away from water sources.
Snakes Often Mistaken for Water Moccasins in California
Several snake species in California are frequently confused with water moccasins. Gopher snakes (Pituophis catenifer) are often mistaken due to their blotched patterns and defensive behaviors. When threatened, gopher snakes can flatten their heads into a triangular shape, hiss loudly, and vibrate their tails, mimicking rattlesnakes. However, gopher snakes are non-venomous and generally have a more slender body compared to the thicker build of a water moccasin.
California garter snakes (Thamnophis genus) are also confused with water moccasins, especially since many species are found near water. Garter snakes typically exhibit stripes down their backs, which can be yellow, orange, red, or white, contrasting with the often banded or solid coloration of water moccasins. While some garter snakes can be quite colorful, they are non-venomous and generally smaller and more slender than water moccasins. Rattlesnakes (Crotalus genus) are venomous and possess a triangular head shape similar to water moccasins. However, rattlesnakes are distinguished by a rattle at the end of their tail and keeled scales, giving them a rough texture.
Identifying a True Water Moccasin
True water moccasins possess distinct physical and behavioral characteristics. They are pit vipers, with heat-sensing pits located between their eyes and nostrils. These snakes typically have a broad, triangular-shaped head noticeably wider than their neck, and their pupils are vertically elliptical, resembling a cat’s eye. A dark stripe often extends from their eye to the angle of their jaw.
Their bodies are generally thick and heavy for their length, with keeled scales that give them a rough appearance. Coloration varies, ranging from dark olive, brown, or black, often with lighter crossbands that may darken with age. When threatened, water moccasins famously display the bright white interior of their mouth, giving them the common name “cottonmouth.” Unlike many non-venomous water snakes that submerge when disturbed, water moccasins often swim with their entire body visible on the water’s surface, holding their head at about a 45-degree angle.
Encountering Snakes in California
When encountering any snake in California, maintain a respectful distance. Most snakes in the state are non-venomous and pose no threat if left undisturbed. Observing snakes from afar allows them to continue their ecological roles, such as controlling rodent populations. If a snake is found in an area where it might be a hazard, such as a backyard, contact local animal control or a professional snake removal service. Attempting to handle or provoke a snake can lead to defensive bites.