A copperhead has an overall rusty-brown or yellowish brown color with hour-glass shaped markings along its spine. Its triangular shaped head has a pit between its eyes and nostrils, thus placing it in the pit viper family, along with rattlesnakes. A copperhead's diet consists of small rodents and the occasional insect. It lives in rocky, wooded areas and often can be found along a the edge of the forest. The copperhead population in Illinois has declined over the decades, due to habitat destruction and interactions with humans. They are still present in the southern part of the state along the Mississippi River and in the Shawnee Hills area.
The timber rattlesnake is a stout snake that can have colors ranging from yellowish-green to brown. Its back is striped heavily with a black "v" shape, it has a triangular head and is a member of the pit viper family. On the tail of a rattlesnake are loosely attached horny segments that they can "rattle," which produces a sound to scare off predators. A rattler hunts small rodents, mainly in wooded areas. It can also be found in areas of disrupted forests, such as an area cleared for building, due to the increase in rodent populations there. However, the timber rattlesnake is listed as threatened in Illinois, mostly from habitat destruction, motor vehicle encounters and unnecessary killing by humans. There is still a moderate population in the Shawnee Hills area.
The eastern massasauga rattlesnake is a pygmy rattlesnake--the smallest venomous species in Illinois. It can reach up to 40 inches, but the average length is only about 25 inches. As with other pit vipers, it has a triangular-shaped head. It is gray to light brown in color and has dark brown bow-tie shaped blotches along its back. The brown spots have a distinct dark ring around them.
The massasauga rattler prefers a moist environment; it is often called a swamp rattler. It eats small rodents and amphibians and will venture into drier areas to find food if needed. Considered endangered throughout Illinois, the snake is thought to exist only in small swamp areas scattered across the state.
The cottonmouth, or water moccasin, ranges in color from olive green to black. The lighter colors are generally more common in younger snakes and occur with ragged cross bands along the back. It is a very large snake and can reach over 40 inches in length. The water moccasin, in part, gets its name because it is an adept swimmer and often lives in sloughs, swamps and lakes. When threatened, it opens its mouth wide to expose the white color inside. It eats fish, amphibians and small rodents. Habitat change--such as the draining of sloughs and swamps--has caused a population decline. However, there is still a healthy population in southern Illinois where the habitat remains undisturbed.
