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Wild About Illinois Snakes! - Family Natricidae

Photos © Scott Ballard. No photographs included within this information may be used on the internet, publications or any other form of media without the photographer's express permission. All rights reserved.
 
 
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Kirtland’s snake (Clonophis kirtlandii)* Photo © Scott Ballard
Kirtland's snake averages 14 to 18 inches in length. It has a red belly with a row of round, black spots down each side. The scales are keeled (ridged). The body is gray or brown above with four rows of black blotches that may be difficult to see.
 
Kirtland's snake lives in or near wet meadows, swamps, wooded hillsides and adjacent meadows, parks and urban areas. This snake is aquatic, but it is often found on land. It can flatten its body when disturbed and hold this position for a long time. It hides under rocks, boards or other objects. Mating occurs in May. The female gives birth to four to 22 young in August or September. This snake eats worms, fishes and slugs. It lives in northeastern and central Illinois.
 
 
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Mississippi green watersnake (Nerodia cyclopion)* Photo © Scott Ballard
The Mississippi green watersnake averages 30 to 45 inches in length. A row of scales is present between the eye and the lip scales. The back is green or brown with dim, black crossbars. The belly has light spots on a gray or brown background. Scales are keeled (ridged). The female is larger than the male.
 
The Mississippi green watersnake lives in cypress swamps and river sloughs. This snake is aquatic but is often seen basking on logs or brush. It is active during the day, hunting for food in late evening. In the hottest summer temperatures, it becomes active at night. It may flatten its body when disturbed and/or release large amounts of nasty-smelling musk from glands at the base of the tail. Mating occurs in the spring. Eggs are retained inside the female, where they develop. Young are born alive in August or September, the number of young varying with the age and size of the female snake. This animal eats fishes and amphibians. In Illinois, it lives in the counties at the southern tip of the state.
 
 
plain-bellied watersnake (Nerodia erythrogaster) Photo © Scott Ballard
Two subspecies of this snake are found in Illinois, the yellowbelly watersnake and the copperbelly watersnake. The yellowbelly watersnake averages 30 to 48 inches in length, has a back which is gray or green-gray and is usually without markings, a yellow belly with a touch of orange and keeled (ridged) scales. The copperbelly watersnake averages 30 to 48 inches in length, has a dark sometimes black back, a red or orange-red belly and keeled (ridged) scales.
 
The plain-bellied watersnake lives in river bottoms, swamps, marshes, edges of ponds and lakes. This snake is aquatic, but it may be seen basking on logs in water or along the shoreline. It may flatten its body when disturbed and/or release large amounts of nasty-smelling musk from glands at the base of the tail. Mating season occurs in April and May. Eggs are retained inside the female for development. Young are born alive in late summer; the number produced varying directly with the size of the female snake. This snake eats fishes, amphibians and crayfish. It may be found in the southern one-third of Illinois.
 
 
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southern watersnake (Nerodia fasciata)** Photo © Scott Ballard
The southern watersnake averages 22 to 36 inches in length. Broad, dark crossbands are present on the back and are separated by areas of yellow. The back is black, brown or red-brown. A dark stripe is present from the eye to the angle of the mouth. The scales are keeled (ridged). The belly is yellow with black or brown squares or blotches.
 
The southern watersnake lives in cypress swamps, river sloughs, oxbow lakes and drainage ditches. This snake is aquatic and is active day and night. It may flatten its body when disturbed and/or release large amounts of stinky musk from glands at the base of the tail. Mating season occurs in April and May. In late summer, the female gives birth to between eight and 50 young, the number depending on her size and age. This snake eats fishes and amphibians. This species is known in Illinois from only one county at the southern tip of the state.
 
 
diamond-backed watersnake (Nerodia rhombifer) Photo © Scott Ballard
The diamond-backed watersnake averages 30 to 48 inches in length. Its back has a pattern of dark, chainlike markings on a background of lighter brown or dirty yellow. The yellow belly is marked with black or brown spots. The scales are keeled (ridged).
 
The diamond-backed watersnake lives in lakes, rivers, ditches, ponds, sloughs and swamps. This snake is aquatic but may be seen basking in the sunshine on limbs over water. It is essentially nocturnal in the hot summer months, but individuals may be active during the day in spring and fall. This snake may flatten its body when disturbed and/or release large amounts of musk from glands at the base of the tail. Mating occurs in spring. About 14 to 60 young per female are born in late summer or early fall, the number of young produced directly related to the size and age of the female. This animal eats fishes and amphibians. It lives in Illinois mainly in the southwestern one-fourth of the state and along major rivers.
 
 
 
northern watersnake (Nerodia sipedon) Photo © Scott Ballard
Two subspecies of the northern watersnake exist in Illinois: the northern watersnake and the midland watersnake. The northern watersnake averages 24 to 42 inches in length. It has red-brown to black markings on the back which are bandlike toward the head and become alternating blotches toward the tail. Some adults show no pattern at all. The red or brown markings on the belly extend to the tip of the tail. The body color may be gray to dark brown. Scales are keeled (ridged). The midland watersnake averages 22 to 40 inches in length. The markings on the back are similar to those of the northern watersnake, but there are fewer of them and they are farther apart. The belly markings tend to be in pairs. The scales are keeled (ridged), and the body color is brown or gray.
 
The northern watersnake lives in streams, ponds, lakes and marshes. This snake is active during the day in spring and fall. It becomes nocturnal in summer. It may flatten its body when disturbed and/or release large amounts of musk from glands at the base of the tail. Mating occurs in the spring. Males locate females by using their sense of smell. In late summer, the female gives birth to between eight and 50 young, depending on her size and age. This snake eats fishes and amphibians. It is found statewide.
 
 
Graham’s crayfish snake (Regina grahamii) Photo © Scott Ballard
Graham's crayfish snake averages 18 to 28 inches in length. Its back is brown or dark olive, and a broad, yellow stripe is present along each lower side. The belly is yellow and may or may not have markings. The scales are keeled (ridged).
 
Graham's crayfish snake lives in ponds, streams, sloughs, swamps and marshes. This snake is semiaquatic. It hides under stones or debris along the water's edge and sometimes in crayfish burrows or other burrows. It basks on rocks and in branches overhanging the water. It is active in the day except in the hot summer months when it becomes nocturnal. This snake may flatten its body when disturbed and/or release large amounts of musk from glands at the base of the tail. It overwinters in crayfish burrows. Mating occurs in spring. The female gives birth to from nine to 40 young in late summer, the number depending on her size and age. Graham's crayfish snake mainly eats crayfish that have just shed their exoskeleton but will also take other crustaceans, amphibians and fishes. Its Illinois range includes most of the state except for the areas drained by the Wabash and Ohio rivers.
 
 

queensnake (Regina septemvittata) Photo © IDNR
The queensnake averages 15 to 24 inches in length. It has a brown back, and a yellow stripe along each lower side of the body. The belly is yellow with four brown stripes. The scales are keeled (ridged).
 
The queensnake lives in creeks and rivers in forested regions. It may take cover under rocks or brush along the water's edge. This snake may flatten its body when disturbed and/or release large amounts of musk from glands at the base of the tail. Mating occurs in spring. The female gives birth to from five to 20 young in late summer, the number depending upon her size and age. The queensnake eats mainly crayfish, especially those which have just shed their exoskeleton. This species lives in the northern one-half of Illinois.
 
 
 
DeKay’s brownsnake (Storeria dekayi) Photo © Scott Ballard
DeKay’s brownsnake averages nine to 13 inches in length. It is usually brown but may be red or gray on the back with an area in the middle of the back lighter than the sides. The scales are keeled (ridged). A dark streak is present on each side of the head. Numerous dark lines cross the back giving it a ladder-back appearance. The belly is yellow, brown or pink.
 
DeKay’s brownsnake lives in parks, cemeteries, urban empty lots, peatlands, floodplains, swamps, marshes, moist woods and hillsides. This snake is active during the day, except in the hottest summer months. It is rarely seen, however, as it spends much time under rocks, logs and other objects on the ground. The brown snake may flatten its body when disturbed and release a substance from its anal scent glands. Mating usually occurs in spring but may also occur in the fall. The female gives birth to from three to 25 young in late summer, the number depending on her size and age. This snake eats slugs, insects and earthworms. It can be found statewide.
 
 
 
red-bellied snake (Storeria occipitomaculata) Photo © Scott Ballard
The red-bellied snake averages eight to 10 inches in length. Although usually brown in color, it may be red or gray on the back. It may show four, narrow dark stripes or a light stripe along the middle of the back. The scales are keeled (ridged). The belly is plain red. Three light spots are present behind the head.
 
The red-bellied snake usually lives in or near open woods but occasionally is seen in wet meadows or pastures. It frequently hides under rocks or other objects. It may occasionally be seen sunning itself. The red-bellied snake may flatten its body when disturbed and release a substance from its anal scent glands. Mating occurs spring, summer or fall. The female gives birth to from one to 20 young in late summer or early fall, the number depending on her size and age. This snake eats slugs, insects and earthworms. This species lives statewide.
 
 
western ribbonsnake (Thamnophis proximus) Photo © Scott Ballard
The western ribbonsnake averages 20 to 30 inches in length. It has a pair of large, light-colored spots on the head, a black back and an orange stripe in the middle of the back. Light stripes are found along the length of the body on the sides. The belly and chin are green-white. The scales are keeled (ridged). The body is very slender with the tail more than one-fourth of the body length.
 
The western ribbonsnake lives in and around streams, ditches, marshes, edges of ponds and lakes and sometimes in upland woods. This semiaquatic animal moves quickly, climbing and swimming easily. It is active during the day in spring and fall, becoming nocturnal in the hottest summer months. When alarmed, it may flatten its body and release an unpleasant musk from the glands at the base of its tail. The western ribbonsnake may hibernate in rock crevices with other snake species. Mating occurs in April or May. The female gives birth to from three to 25 young in July or August, the number depending on the female's size and age. This snake eats frogs, toads, salamanders, fishes, tadpoles, earthworms, leeches, small mammals and birds. In Illinois, it is most commonly found along the Mississippi River and in the northeastern section of the state.
 
 
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plains gartersnake (Thamnophis radix) Photo © Scott Ballard
The plains gartersnake averages 15 to 28 inches in length. The name "gartersnake" comes from the striped appearance of the body, similar to that of the garters that were once commonly used to support men's socks. Three longitudinal stripes are found on the body with black spots between the stripes and below each side stripe. The stripe in the center of the back is yellow or orange while those on the sides are yellow-gray. The lips have black bars, and the gray-green belly has two rows of black spots. The back is brown or green. The scales are keeled (ridged).
 
The plains gartersnake lives in river valleys, prairie ponds, sloughs, meadows and pastures. It was once common in vacant lots in cities. Active in the day, this snake may be seen basking in the sun. It takes shelter under objects on the ground. It is believed to overwinter in abandoned rodent burrows. When alarmed, the plains gartersnake may flatten its body and release fecal matter and an unpleasant musk from glands at the base of the tail. Mating occurs in the spring. The female gives birth to from 10 to 30 young in late summer, the number depending on her size and age. The plains gartersnake eats frogs, toads, salamanders, fishes, tadpoles, earthworms, leeches, small mammals and birds. It lives in the northern one-half of the state.
 
 
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eastern ribbonsnake (Thamnophis sauritus)* Photo © Scott Ballard
The eastern ribbonsnake averages 18 to 26 inches in length. Its very slender body has three, yellow longitudinal stripes on a dark background. The belly is yellow or green. The tail comprises almost one-third of the total body length. The scales are keeled (ridged).
 
The eastern ribbonsnake lives in and around streams, ponds and swamps which have quiet, shallow water, much vegetation and plenty of sunlight. This snake is semiaquatic, spending time on land and in water. When alarmed, it may flatten its body and release an unpleasant musk from glands at the base of its tail. The female gives birth to from three to 25 young in late summer, depending on her size and age. This snake eats salamanders, frogs and small fishes. It lives in the southeastern one-fourth of Illinois.
 
 
 
common gartersnake (Thamnophis sirtalis) Photo © Scott Ballard
The common gartersnake averages 18 to 26 inches in length. Two subspecies are found in Illinois: the eastern gartersnake and the Chicago gartersnake. The name "garter snake" comes from the striped appearance, similar to that of the garters that were once commonly used to support men's socks. The appearance is variable. This snake may have either stripes or spots. If stripes are present there will be three, which are usually yellow but may be other colors. Usually a double row of black spots may be found between the stripes. The belly is green or yellow with two rows of indistinct black spots. The scales are keeled (ridged). The Chicago gartersnake differs from the eastern gartersnake in having the side stripes broken by vertical black crossbars.
 
The common gartersnake lives in meadows, marshes, woodlands, hillsides, stream edges and vacant city lots. This snake is terrestrial and active during the day. It will climb and swim. It hides under vegetation, boards or other objects on the ground. When alarmed, it may flatten its body and release an unpleasant musk from glands at the base of the tail. It overwinters in rock crevices or in the burrows of other animals. Mating occurs in early spring. Young are born alive in the period late summer through early fall. The female gives birth to between seven and 85 young at one time, depending on her size and age. This snake eats earthworms, frogs, toads, salamanders, insects, mice and small birds. It lives throughout Illinois.
 
 
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lined snake (Tropidoclonion lineatum)* Photo © Scott Ballard
The lined snake averages eight and three-fourths to 15 inches in length. It has a double row of black half-moons on its belly. The back is brown with three, gray, longitudinal stripes. The scales are keeled (ridged).
 
The lined snake lives in vacant lots and prairies, where it may be found under rocks or debris during the day. This snake is active at night. When alarmed, it may release an unpleasant musk from glands at the base of the tail. Mating occurs in the fall. Two to 12 young per brood are born to the female in August or September. This snake eats earthworms. In Illinois, it is found in the central one-third of the state.
 
 
 
smooth earthsnake (Virginia valeriae) Photo © Scott Ballard
The smooth earthsnake averages seven to 10 inches in length. It has a gray or red-brown back with no markings and a white or yellow belly. The scales are smooth or weakly keeled (ridged).
 
The smooth earthsnake lives in moist, wooded hillsides and abandoned fields where it generally hides under rocks. This snake stays underground for long periods of time, coming out after heavy rains. It is active mainly at night. Mating occurs in May or June. Two to 14 young are born to the female in August or September. This snake eats earthworms, slugs and soft-bodied insects. It may be found in the southern one-half of the state.
 
 
* = threatened in Illinois
** = endangered in Illinois

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