VenomousSnakes - Illinois DNR20 / Outdoor Illinois March 2010 Is it poisonous or venomous? TAhere is...
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20 / OutdoorIllinois March 2010 Is it poisonous or venomous? There is a difference. A poisonous plant or animal causes harm if touched or consumed. Venomous organisms inject a toxin to subdue their prey, as is done by the hollow fangs of the four species of pit vipers found in Illinois— copperhead (Agkistrodon contortrix), cottonmouth (Agkistrodon piscivorus), timber rattlesnake (Crotalus horridus) and eastern massasauga (Sistrurus cate- natus). The pit is a large opening between the eye and nostril used to detect heat emitted by their prey. Ven- omous snakes in Illinois also have an elliptical pupil. Venomous snakes are not aggressive and tend to bite people only when stepped on, picked up or cornered. Learn to identify, and avoid these snakes when possible. Copperheads have a light tan or rusty ground color and 10-20 darker brown, hourglass-shaped crossbands that are narrow on the back and widen on the sides. Locally abundant in wood- ed, rocky hillsides in the southern one- third of Illinois, south of Route 16, and in the lower Illinois River valley, cop- perheads prefer upland forests or bluffs with limestone or sandstone outcrop- pings. The stout-bodied cottonmouth is relatively abundant in swamps, sloughs and wet bottomlands in extreme south- ern Illinois, south of Illinois Route 13. Young snakes have 12-18 dark cross- bands on a brown or dark-brown back, and a wide, dark stripe from the nose through the eye and upper lip. Older adults are dark olive or black. When threatened, cottonmouths open their mouth, displaying a whitish lining. Found in heavily timbered areas with river bluffs and rock outcrops in the southern one-fourth of the state, the lower Illinois and Mississippi river valleys and a few other locations is the timber rattlesnake. These stout-bod- ied snakes are gray to light yellow to greenish-white, with 20-25 black, jagged bands, and sometimes a rusty stripe down the back. A dark stripe is behind each eye. Timber rattlesnakes are listed as threatened in Illinois. Prairie wetlands, wet oldfields and river floodplains in Madison, Clinton, Piatt, Knox, Warren, Will, Cook and Lake counties provide habitat for the state-endangered Eastern massas- auga. The smallest venomous snake in Illinois, massasaugas are light brown to gray and have 29-40 light-edged brown or black spots down their back and three rows of smaller blotches along each side. A small rattle is at the end of the tail. Venomous Snakes eastern massasauga (Sistrurus catenatus) eastern massasauga (Sistrurus catenatus) timber rattlesnake (Crotalus horridus) timber rattlesnake (Crotalus horridus) cottonmouth (Agkistrodon piscivorus) cottonmouth (Agkistrodon piscivorus) copperhead (Agkistrodon contortrix) copperhead (Agkistrodon contortrix)
Transcript of VenomousSnakes - Illinois DNR20 / Outdoor Illinois March 2010 Is it poisonous or venomous? TAhere is...
20 / OutdoorIllinois March 2010
Is it poisonous or venomous?There is a difference.
Apoisonous plant or animalcauses harm if touched orconsumed. Venomousorganisms inject a toxin tosubdue their prey, as is
done by the hollow fangs of the fourspecies of pit vipers found in Illinois—copperhead (Agkistrodon contortrix),cottonmouth (Agkistrodon piscivorus),timber rattlesnake (Crotalus horridus)and eastern massasauga (Sistrurus cate-natus). The pit is a large openingbetween the eye and nostril used todetect heat emitted by their prey. Ven-omous snakes in Illinois also have anelliptical pupil.
Venomous snakes are not aggressiveand tend to bite people only whenstepped on, picked up or cornered.
Learn to identify, and avoid thesesnakes when possible.
Copperheads have a light tan orrusty ground color and 10-20 darkerbrown, hourglass-shaped crossbandsthat are narrow on the back and widenon the sides. Locally abundant in wood-ed, rocky hillsides in the southern one-third of Illinois, south of Route 16, andin the lower Illinois River valley, cop-perheads prefer upland forests or bluffswith limestone or sandstone outcrop-pings.
The stout-bodied cottonmouth isrelatively abundant in swamps, sloughsand wet bottomlands in extreme south-ern Illinois, south of Illinois Route 13.Young snakes have 12-18 dark cross-bands on a brown or dark-brown back,and a wide, dark stripe from the nosethrough the eye and upper lip. Olderadults are dark olive or black. Whenthreatened, cottonmouths open theirmouth, displaying a whitish lining.
Found in heavily timbered areaswith river bluffs and rock outcrops inthe southern one-fourth of the state,the lower Illinois and Mississippi rivervalleys and a few other locations is thetimber rattlesnake. These stout-bod-ied snakes are gray to light yellow togreenish-white, with 20-25 black,jagged bands, and sometimes a rustystripe down the back. A dark stripe isbehind each eye. Timber rattlesnakesare listed as threatened in Illinois.
Prairie wetlands, wet oldfields andriver floodplains in Madison, Clinton,Piatt, Knox, Warren, Will, Cook andLake counties provide habitat for thestate-endangered Eastern massas-auga. The smallest venomous snake inIllinois, massasaugas are light brown togray and have 29-40 light-edged brownor black spots down their back andthree rows of smaller blotches alongeach side. A small rattle is at the end ofthe tail.
Venomous Snakes
eastern massasauga (Sistrurus catenatus)eastern massasauga (Sistrurus catenatus)timber rattlesnake (Crotalus horridus)timber rattlesnake (Crotalus horridus)
cottonmouth (Agkistrodon piscivorus)cottonmouth (Agkistrodon piscivorus)copperhead (Agkistrodon contortrix)copperhead (Agkistrodon contortrix)
