Wisconsin is home to a diverse array of snake species that play an integral role in the state’s natural ecosystems. These reptiles contribute significantly to ecological balance, often controlling populations of rodents and insects.
Non-Venomous Snakes of Wisconsin
Many non-venomous snake species thrive across Wisconsin, each with distinct appearances. The Common Garter Snake, Wisconsin’s most abundant snake, typically displays yellow stripes along its sides and a lighter stripe down its back, with overall coloration varying from green, brown, or black. These snakes typically measure between 17 and 30 inches. The Eastern Hognose Snake is identified by its characteristic upturned snout. Its body often features dark brown blotches on a brown-gold background, and it can grow to about 20 to 35 inches in length.
The Northern Water Snake, a medium-sized and heavy-bodied reptile, typically exhibits brown, grayish, or reddish-brown banding or blotches. These snakes can reach lengths of 24 to 48 inches and are frequently observed near water bodies. The Milk Snake is characterized by its gray or light brown background color, adorned with three rows of reddish-brown or brown blotches bordered in black. A distinctive whitish Y or V-shaped marking is often present on the top of its head near the neck, and adults typically range from 24 to 36 inches. The DeKay’s Brownsnake is a small, thick-bodied snake, usually gray or light brown, with a light mid-dorsal stripe bordered by two rows of small dark spots, generally measuring between 8 and 15 inches. These non-venomous snakes are harmless to humans.
Venomous Snakes of Wisconsin
Wisconsin is home to only two venomous snake species, both rattlesnakes: the Timber Rattlesnake and the Eastern Massasauga. Both species are classified as pit vipers. The Timber Rattlesnake is a large, heavy-bodied snake, typically ranging from 3 to 5 feet in length, though some individuals can exceed 6 feet. Its coloration varies, often appearing yellowish to gray or nearly black, with distinct dark brown or black crossbands and a black tail tipped with a prominent rattle. In Wisconsin, the Timber Rattlesnake is designated as a “Special Concern” species and a “Protected Wild Animal.”
The Eastern Massasauga is a smaller, more secretive rattlesnake, usually measuring between 2 and 3 feet in length. It has a heavy body and is typically gray or light brown, marked with chocolate brown blotches that often have lighter edges, and smaller blotches along its sides. While it possesses a faint rattle, sometimes described as an insect-like buzz, this species holds the status of State Endangered and Federally Threatened due to significant population declines. Encounters with both venomous species are rare, and they are generally not aggressive unless provoked or threatened.
Snake Habitats and Behaviors
Snakes in Wisconsin inhabit a variety of environments, adapting their lives to suit different landscapes. Habitats include forests, wetlands, grasslands, rocky bluffs, and areas near water sources. Northern Water Snakes are commonly found near fresh water bodies like lakes, ponds, and rivers, often basking on rocks or logs along the shore. Timber Rattlesnakes prefer rugged, rocky terrain, including bluffs and hillsides, where they can find suitable den sites.
Snake diets are varied. Many species, like the Common Garter Snake, consume a range of prey including frogs, toads, salamanders, fish, and earthworms. Eastern Hognose Snakes primarily feed on toads, utilizing specialized teeth to handle their prey. Milk Snakes and Timber Rattlesnakes largely prey on small mammals, such as rodents, while DeKay’s Brownsnakes feed on small invertebrates like slugs, earthworms, and snails. Snake activity patterns vary; many are diurnal, but some become nocturnal during warmer weather. During colder months, Wisconsin snakes enter a state of brumation, often hibernating in communal dens or burrows to escape freezing temperatures.
Coexisting with Wisconsin Snakes
Encountering a snake in Wisconsin requires understanding how to respond safely. Observe snakes from a respectful distance; never attempt to handle or harass them. Snakes are not inherently aggressive and typically bite only when threatened or handled. They serve a beneficial ecological role, particularly through their consumption of rodents and insects.
Many snake species in Wisconsin, including both venomous rattlesnakes, are afforded legal protections, making it illegal to harm or remove them. When in natural habitats where snakes might be present, such as rocky areas or dense vegetation, watch where you step and place your hands. Respecting their space and understanding their contribution to the ecosystem allows for peaceful coexistence with these animals.