Prairie Rattlesnake

Quick Take

• Rattlesnakes are born without their signature rattle, and the process that gives them one is surprisingly complex. Rattle development explained →
• Prairie rattlesnakes evolved to deliberately discard venom capabilities, and this evolutionary trade-off made them more dangerous, not less. How venom evolved →
• Prairie rattlesnakes don't always rattle before they strike, and knowing when they won't could matter more than you think. Rattling behavior facts →
• Baby prairie rattlesnakes can't rattle yet, though that doesn't make them any less dangerous to handle. Baby snake details →

The prairie rattlesnake is one of the most well-known and easily recognized types of pit viper in the world. These snakes like to live in arid and grassy environments and are found throughout the central United States.

Although they do not typically pose a threat to humans, prairie rattlesnakes are highly venomous and should be avoided. However, as long as you respect their boundaries, prairie rattlesnakes are a welcome and harmless part of the local ecosystem.

Incredible Prairie Rattlesnake Facts

• Rattlesnakes aren’t born with their rattles. Instead, they have a tiny nub at the end of their tail, and they grow another link every time they shed their skin. After shedding 2 to 3 times, the snake is capable of making a rattling sound.
• Some rattlesnake species have incredibly high venom toxicity and are capable of delivering a bite that can kill humans and other large mammals.
• Female rattlesnakes don’t lay eggs. Instead, the eggs hatch while still inside the female’s body, and she gives birth to live hatchlings.
• Prairie rattlesnakes don’t have great eyesight. Instead, they hunt using their exceptional sense of smell and sensitivity to movement.

Evolution And History

The rattlesnakes of today evolved around 12 to 14 million years ago, from an ancestor whose genes produced venom that targeted all areas — the blood, the nervous system, and the muscles. During evolution, the rattlesnake quickly shed certain genes that produced a wide variety of toxins and focused on one area, driving faster evolution and now gives the snake specialized venom. Each species of rattlesnake has a distinctive variation in its venom.

Classification and Scientific Name

The scientific name of the prairie rattlesnake is Crotalus viridis. The name ‘Crotalus‘ comes from the Greek word for ‘rattle’ and likely refers to the distinctive rattle at the end of each rattlesnake’s tail. The word ‘viridis‘ comes from the Latin word for ‘green,’ which reflects the snake’s characteristic greenish coloring.

Although there were once many different recognized subspecies of Crotalus viridis, since 2001 they have been condensed into two. Crotalus viridis, which can be found east of the Rocky Mountains, now includes the conventional species known as Crotalus viridis viridis (prairie rattlesnake) and the Hopi rattlesnake (Crotalus viridis nuntius). Meanwhile, the recognized species found west of the Rocky Mountains is now called the Northern Pacific rattlesnake (Crotalus oreganus).

Appearance And Behavior

Prairie rattlesnakes are rather large snakes that often grow to be three feet or longer. The largest ever recorded prairie rattlesnake was 4.97 feet long. Prairie rattlesnakes are usually light brown in color with darker brown patches that are often bordered in either tan or white. This species can be recognized immediately by its thin neck, triangle-shaped head, and distinctive tail rattle. This rattle is made of interlocking keratin segments that clatter together when the tail is shaken. Rattlesnakes often use this sound as a warning, although they do not always rattle before they strike.

Rattlesnakes are a mostly solitary species, although it’s not uncommon to find multiple snakes basking in the same location. Most rattlesnakes stay within the boundaries of their home range; however, because they are not territorial, they will often share this range with other snakes, especially if there are enough food resources.

Habitat

Prairie rattlesnakes can be found across the United States in plains, foothills, and other arid environments to the east of the Rocky Mountains. These snakes crawl through the grass to hunt, bask on sunny rocks, and live in unoccupied prairie dog burrows and other small crevices. You can also find prairie rattlesnakes in wooded areas that are capable of providing plenty of food, sunshine, and places to hide.

In general, prairie rattlesnakes are active during the mornings and evenings. These snakes are largely diurnal but switch to more nocturnal behaviors when the heat of summer arrives. It’s not abnormal to find prairie rattlers hiding in shadowy areas underneath porches or rocks, especially if the weather is particularly hot or humid.

Prairie rattlesnakes hibernate during the winter. Interestingly, the same snake will often return to the same home den year after year. Upon waking in the spring, the rattlesnake will migrate back to a nearby hunting territory and settle into a home range.

Predators And Threats

Prairie rattlesnakes only eat when they are hungry. Younger rattlesnakes need to eat once a week, while adult rattlers often go as much as two weeks between meals. When it’s time for food, the hungry rattlesnake will hunt until it finds a small animal such as a mouse, rat, rabbit, bird, or prairie dog. Then, the rattlesnake strikes the prey with a venomous bite before retreating and following from a safe distance. Once the prey dies from venom toxicity, the rattlesnake will appear and eat it.

All small animals are potential prey for prairie rattlesnakes. When they can’t find a mammal, rattlesnakes have also been known to hunt birds, amphibians, and even other reptiles. The rattlesnake’s venom is so potent that most large animals avoid them. It’s smart to keep dogs, cats, and other large pets away from areas where prairie rattlesnakes might be present.

However, as dangerous and capable as these snakes are, they are also susceptible to their own natural predators. In particular, prairie rattlesnakes must be wary of hawks, owls, and other birds of prey. Foxes, coyotes, skunks, bobcats, and other predatory mammals have also been known to catch rattlesnakes for an occasional meal.

Prairie rattlesnakes are incredibly resourceful and generally maintain stable population numbers. The current biggest threats to the rattlesnake’s existence are habitat reduction and intentional hunting by local humans. Before attempting to exterminate the rattlesnakes on your land, contact a local park ranger to see if there are any regulations or population concerns.

Reproduction, Babies, And Lifespan

Prairie rattlesnakes don’t reach sexual maturity until they are at least 4 years old. Mating season occurs once a year during the spring. Although it’s suspected that males attempt to mate every year, females only seek out mating once every 2 to 3 years. After mating, the females will retreat to a communal den, where they will usually give birth sometime in late August.

Prairie rattlesnakes give birth to live young rather than laying eggs. One female will usually give birth to between 4 and 25 baby snakes at a single time. Baby snakes are capable of caring for themselves, but they will usually remain in the communal den until they grow large enough to feel crowded and compete for resources.

When born, baby rattlesnakes are between 8.7 and 11 inches (22 and 28 centimeters) long. Young snakes have full fangs with normal venom effects, making them unsafe for handling by anyone other than an experienced professional. Interestingly, baby rattlesnakes do not have rattles; instead, they have a tiny nub at the end of their tail. A new nub will be added every time the snake sheds its skin; most snakes can rattle after shedding about 2 to 3 times.

Prairie rattlesnakes grow quickly during their first year and can often double in size. Once they mature into adults, their growth rate slows to a rate of about 1.2 to 2 inches (3 to 5 centimeters) a year. Unfortunately, due to their small size and strong competition for resources, most young rattlesnakes don’t survive their first year and are taken by birds or other predators. However, if they survive into old age, prairie rattlesnakes can live up to 31 years.

Population

Prairie rattlesnakes are incredibly common throughout the central United States and across the Great Plains. Currently, no population estimates are available. However, frequent enough sightings have allowed this animal to be labeled as of least concern.