The prairie rattlesnake is the most common subspecies of Crotalus viridis. It is a venomous pitviper native to western North America. Prairie rattlesnake is the most common name, but is also referred to as a western rattlesnake, or sometimes a plains rattlesnake.
A prairie rattlesnake is usually identified by its triangular head, distinctive rattle, and pit organs on the face. Prairie rattlesnakes are usually shades of green and brown, and have a set of dark brown patches along their dorsal side, or back. Their ventral side, or stomach, is usually grey or white in color. Adult rattlesnakes are usually near 35 inches (90 centimeters) in length.
All pitvipers are characterized by pit organs on each side of the head, located between the nostrils and the eyes. Pit organs allow the snakes to sense heat. The pit organ, along with the sense of smell that snakes possess in their tongues, allows pitvipers to more accurately locate prey. Sensing heat through the pit organ also allows snakes to actively regulate their body temperature by moving to the most advantageous location.
Prairie rattlesnakes, as the name suggests, most commonly inhabit prairies or grasslands. They are most commonly found in the western United States, northern Mexico, and southwestern Canada. Like all snakes, they are cold-blooded, and are thus usually found in the warm sun during the mild part of the day, and in burrows, dens, or caves when the weather is cold or too hot. Prairie rattlesnakes usually inhabit burrows or shelters that were dug by other animals, and multiple snakes may share the same den. Rattlesnakes hibernate during the winter, and it is not uncommon for hundreds of prairie rattlesnakes to hibernate in one shelter.
Small rodents and birds are the most common prey of a prairie rattlesnake, although rattlesnakes may also eat amphibians, and other snakes. The snakes strike at their prey with their fangs, delivering a dose of venom to the animal. Rattlesnake venom works to both paralyze and partially breakdown the prey, allowing the snake to remain out of harm’s way until the prey is docile enough to be consumed. The venom of prairie rattlesnakes is dangerous to humans, however, the snake is not aggressive, so human deaths are rare.
Common predators of the prairie rattlesnake are birds of prey, such as hawks and owls. The snakes use their rattles to make a rattling sound to warn and intimidate predators when they get close. The rattle itself is made by a set of hollow keratin, or stiff protein, pieces at the tip of the snake’s tail. By rapidly twitching specialized muscles near the tail, rattlesnakes are able to produce the characteristic rattling sound.
In addition to predators, another significant danger to prairie rattlesnakes is human development. Development and expansion of cities and industry compromises or destroys rattlesnake habitat. Prairie rattlesnakes are not an endangered species, but they are protected in some regions.