(Crotalus viridis)
Average Size: 35-45 inches in length (89-114 cm), record length 57 inches (144.8 cm).
Distinguishing Characteristics: The prairie rattlesnake is a blotched snake over most of its body, but the blotches become dark stripes or crossbands near the tail. Main color of the snake is usually a grsyish-green or greenish-brown; the blotches are brown and bordered with white. Note a light line behind the eye that passes above the mouth.
Range: Found throughout most of the United States west of the Missouri River, although may also be found just east of this river as well. There are at least 2 subspecies of the prairie, one found toward the central U.S., and the other found in the western half of its range. The prairie rattlesnake has the largest range of any rattlesnake.
Habitat: The prairie rattlesnake lives in a variety of habitats, from open prairie to suburban areas and even ascends into mountainous regions. In western South Dakota they can be found both in the Badlands and in the Black Hills, and areas in between. They are locally common in some areas. “Prairies” are well-known in prairie dog towns, where they will even feed on prairie dogs and burrowing owls (contrary to popular myths).
Primary Foods: Like other rattlesnakes, prairies feed mostly on small rodents, but will also eat other warm-blooded prey and perhaps insects when they are young.
Breeding: Young are born live (not from eggs) and are 8-11 inches (21.5-28 cm) in length at birth.
Other Behavior: Rattlesnakes are most famous for their venom, which they inject through their fangs when they bite their prey. This venom is a modified form of saliva and begins the digestion process in addition to killing the prey animal. Rattlesnakes have control over the amount of venom they inject with a bite, and many bites that occur in humans contain no venom at all (a “dry bite”). Nonetheless, if bitten, the best course of action is to immediately – and calmly – get to the hospital where antivenom (antivenin) can be administered.
Rattlesnakes do normally have “rattles” on the end of their tails. They can shake these when frightened to warn off large animals like humans. However, they do not always rattle before biting, nor do they always bite when they rattle. Plus, rattlesnake rattles are made from the same material as our fingernails and frequently break off during normal wear and tear. So, do not rely upon the sight or sound of a rattle to alert you to danger!
Other Similar Snakes: There are several other species of rattlesnakes found in the United States (the Diamondback and the Mojave are just 2 others). There are also many other venomous snakes found in the U.S. (like the Cottonmouth and the Coral Snake). However, the prairie rattlesnake is the only venomous snake native to South Dakota.