Wisconsin Native Snakes

Common Garter Snake, Thamnophis sirtalis
Snakes play very important roles in many natural communities as predator and prey.

Snakes are extremely valuable to the agricultural community by keeping grain eating mammals in check. Recent studies suggest that snakes are also valuable in reducing disease threats posed by high rodent populations.

Many snake populations have declined in Wisconsin due to habitat loss and human persecution. Even today, people who do not understand or appreciate their value continue to needlessly kill them. Of Wisconsin's 21 species, 14 are considered rare and listed as endangered, threatened or special concern.

Wisconsin Native Snakes Catalog
Profiles of Snakes Commonly Found in Wisconsin

  Snakes Are Reptiles

Reptiles are a class of vertebrates made up mostly of snakes, turtles, lizards, and crocodilians. These animals are most easily recognized by their dry, scaly skin. Almost all reptiles are cold-blooded and most lay eggs, though some give birth to live young. Instead of possessing gills like fish or amphibians, reptiles have lungs for breathing.

  Snake Mimicry

There are two species of rattlesnakes in Wisconsin, the Timber Rattlesnake and the Eastern Massasauga. Both species are very rare.

But there are many non-venomous snake species that often mimic rattlesnakes. These mimics vibrate their tails when they feel threatened. The sound of their tail “rattling” against vegetation, gravel or dry leaves sounds almost identical to a rattlesnake.

  Hibernation (Brummation)

Being cold-blooded (ectothermic) and thus unable to regulate their own body temperature with metabolic activity, snakes are vulnerable to low temperatures. To deal with subfreezing weather, snakes in Wisconsin hibernate during winter, although some scientists restrict that term to warm-blooded creatures and instead refer to the overwintering dormancy of snakes as brumation.

  Snake Life Cycle


After mating, the female snake stores the sperms in the oviduct for about 1 to 2 months. The female then produces large eggs, which after releasing from the ovary are fertilized by the sperms from the oviduct. It lays the fertilized eggs, about 10 to 15, in shallow holes or under the rocks. The outer covering of snake’s egg is not hard, rather it resembles a soft leather.

The female snake guards and looks after the eggs till they hatch into young ones.

Juvenile Snakes

Some snake species warm the eggs by twitching their muscles, so as to speed up the hatching process. The juvenile snake comes out of the egg, by biting the egg cover with the help of egg tooth. Until then, it obtains nutrition from the egg yolk.

A young snake is known as a snakelet. A just hatched one can be called a hatchling. Baby snakes feed on small reptiles and rodents. A young snake may shed its skin up to 4 times a year.

About 20% of the total snake species, especially those adapted to cold regions, give birth to live young (viviparous). Some female snakes lay eggs even without fertilization, which is referred to as parthenogenesis.

Adult Snakes

After the juvenile snakes emerge, they attain maturity, usually within 2 to 4 years. One of the major distinguishing features between a young snake and an older snake is the frequency of molting per year. In case of a juvenile snake, skin shedding takes place about 4 times a year, whereas an adult snake sheds only once a year, at the most, 2 times per year. However, unlike insects in which molting allows the growth of the organism, renewal of skin in snakes does not have a significant role in their growth.

  Snake Diet

All snakes are carnivorous (meat-eaters). Snakes eat rodents and other mammals, birds, reptiles, fish, amphibians, insects and eggs. Some snakes, like rattlesnakes, are venomous and kill or paralyze their prey by injecting poison through hollow fangs. The venom from venomous snakes paralyzes the nervous system, causes heart and lung failure, or causes internal bleeding of their prey.

Catalog of Wisconsin Native Snakes

Common Name Genus Species Status
Butler's Gartersnake Thamnophis butleri Special Concern
Common Gartersnake Thamnophis sirtalis Common
Common Watersnake Nerodia sipedon Common
DeKay's Brownsnake Storeria dekayi Common
Eastern Foxsnake (Pine) Pantherophis vulpinus Common
Eastern Hog-nosed Snake Heterodon platirhinos Common
Eastern Massasauga Sistrurus catenatus Endangered
Eastern Ribbonsnake Thamnophis sauritus Endangered
Gophersnake (Bullsnake) Pituophis catenifer Special Concern
Gray (Black) Ratsnake Pantherophis spiloides Special Concern
Lined Snake Tropidoclonion lineatum Special Concern
Milksnake Lampropeltis triangulum Common
North American (Blue) Racer Coluber constrictor Special Concern
Northern Ring-necked Snake Diadophis punctatus edwardsii Common
Plains Gartersnake Thamnophis radix Special Concern
Prairie Ring-necked Snake Diadophis punctatus arnyi Special Concern
Queensnake Regina septemvittata Endangered
Red-bellied Snake Storeria occipitomaculata Common
Smooth Greensnake Opheodrys vernalis Common
Timber Rattlesnake Crotalus horridus SpecialConcern
Western Ribbonsnake Thamnophis proximus Endangered
Western Wormsnake Carphophis vermis Special Concern

Native Snakes Commonly Found In Wisconsin

Common Watersnake, Nerodia sipedon

Common Watersnake

This is a medium to large heavy-bodied snake, 24 to 40 inches in length. The background color is gray, brown or tan and is marked with dark brown, red-brown or black transverse blotches, which often fade with age. The underside is distinctive, white with bright red half-moons interspersed irregularly with dark gray speckling.

Common watersnakes are usually found in or close to any permanent waterbody but they prefer clean rivers.

DeKay's Brownsnake, Storeria dekayi

DeKay's Brownsnake

This short thick-bodied snake, 8 to 15 inches in length, is gray or light brown in color, and is marked with a light mid-dorsal stripe bordered by two rows of small dark spots. The underside is white or light pink with dark pencil-point spots along the edges of the belly scales. Brownsnakes live in the surface litter in many habitats, including oak savannas, prairies, southern lowland hardwoods, marshes, old fields and under rubbish in vacant city lots.

Eastern Hog-nosed Snake, Heterodon platirhinos

Eastern Hog-nosed Snake

This medium-sized snake, 20 to 25 inches in length, also referred to as a "puff adder", has a sharply upturned snout. The back has dark brown blotches on a brown-gold background color, and their underside varies from mottled yellow to mottled gray or pink. Large, older adults are usually dark brown or gray and may be patternless.

Most hognose snakes have a pair of dark black blotches on their neck that resemble "eyespots" when they flatten their neck. Habitats include bracken grassland, oak savanna and sand prairies.

Milksnake, Lampropeltis triangulum


This snake which is 24 to 26 inches in length has a gray or light brown background color with three rows of reddish-brown or brown blotches bordered with black. There is usually a whitish Y or V shaped marking on the top of its head toward the neck. The underside is white with black rectangular markings.

Milksnakes live in oak savannas, northern and southern upland hardwoods, prairies and old woodlots and pastures.

Northern Ring-necked Snake, Diadophis punctatus edwardsii

Northern Ring-necked Snake

A small, slender snake reaching a maximum total length 28 inches. Body uniformly bluish black to slate gray or brownish, with a cream to yellow collar across neck. The snake's collar may be complete or broken (or constricted) at middorsal line; venter cream to yellow and immaculate, or patterned with a single midventral row of small black spots to large half-moon-shaped spots; head black with white supralabials and a white chin.

Red-bellied Snake, Storeria occipitomaculata

Red-bellied Snake

Ring-necked snakes are small and thin, measuring from 9 to 15 inches in length. The body is a dull blue-gray body, with a bright yellow belly that may have black spots. The black head is flattened, and the scales are smooth and polished.

Ring-necked snakes are found in gardens, meadows, deciduous forests and rocky areas. Typical food items of the ring-necked snake include small salamanders, snakes, and earthworms.

Smooth Greensnake, Opheodrys vernalis

Smooth Greensnake

This species is often called the grass snake due to its color. The name "smooth" refers to the unkeeled scales which give the snake a sleek, smooth texture and appearance. This beautiful little snake which is 14 to 24 inches in length is one of only five Wisconsin snakes to have unkeeled scales.

Smooth greensnakes frequent prairies, oak savannas, bracken grasslands, open areas in pine barrens and grassy areas along forest edges. Greensnakes feed on insects, grubs and worms.

Eastern Foxsnake, Pantherophis vulpinus

Eastern Foxsnake

The Eastern Foxsnake, which is 36 to 56 inches in length has many large reddish-brown, chocolate brown or black mid-dorsal blotches along its back and other smaller blotches on its sides on a background color of yellow, tan or olive gray. The head of adults is usually a dark copper, rust or orange color.

They live in a variety of open habitats including marshes, sedge meadows, prairies and old fields. Their diet consists primarily of rodents and ground-nesting birds.

Read More:

 Groundhog or Woodchuck: Facts, Photos and Control
 Beavers: Nature's Hydrologist
 Wisconsin Native Salamanders
 Wisconsin Native Turtles
 North American Native Turkey

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