Rattlesnakes

Rattlesnakes belong to the genera Crotalus and Sistrurus in the pit viper family. There are around 90 species and subspecies of rattlesnakes, and they are among the most easily recognized and deadliest snakes worldwide. While not a distinct scientific classification, rattlesnakes are grouped together due to the characteristic rattles at the end of their tails. These snakes are responsible for the highest number of fatal snakebites in the US and North America.

Characteristics That Define Rattlesnakes

The primary characteristic of rattlesnakes is the rattle, which is also their most important adaptation. They shake their tails to make a distinct ‘rattling’ sound, which acts as a warning to ward off potential threats and predators.

The rattles are donut-shaped segments made of keratin, stacked one on top of another. These are actually modified scales from the tip of the tail. The snakes get their first rattle at about 2 weeks of age. After that, every time it sheds, a rattle segment is added. A special shaker muscle near the snakes’ tails contracts up to 90 times per second to shake the rattle and make the typical noise.

These snakes also have a pair of heat-sensing pits on their face, a common feature for all pit vipers, to detect warm-blooded prey.

List of Different Types of Rattlesnakes

Rattlesnakes originate from continental North America and are still widespread in various habitats, from Canada to the United States and Mexico. Later, once the Isthmus of Panamá connected the North and South Americas, some rattlesnake populations dispersed to South America and adapted to various habitats there. The South American rattlesnake is the main example of such dispersal and adaptation.

So, all rattlesnakes, save the South American rattlesnake and its subspecies, are found only in the continent of North America, including various Central American regions.

Here is a complete list of rattlesnake species and subspecies, with their typical habitats and characteristic features:

Name		Size	Where You Might Encounter It	How to Identify
Eastern Diamondback Rattlesnake	Crotalus adamanteus	3-6 ft	Prefers dry pine forests and coastal barrier islands in the Southeastern U.S.	Yellowish brown with distinctive diamond patterns having light borders and a center.
Western Diamondback Rattlesnake	Crotalus atrox	3-6 ft	Arid regions and grassy plains, from Central Arkansas to Southern California and Mexico.	Diamond-shaped markings, distinct bands near the tail, pink to brown ground color
Tortuga Island Diamond Rattlesnake	C. a. tortugensis	2.5-3.5 ft	Arid and rocky habitats in Tortuga Island, Mexico.	Light brown or tan with diamon patterns along the back.
Mojave Desert Sidewinder	Crotalus cerastes	1.5-2 ft	Sandy desert areas within the Mojave Desert, Sonora, and Baja California	Horn-like scales above the eyes and distinctive sidewinding tracks.
Sonoran Sidewinder	C. c. cercobombus	1.5-2 ft	Sonoran Desert in Arizona and California.	A black rattle segment connecting the body and tail.
Colorado Desert Sidewinder	C. c. laterorepens	1.5-2 ft	Higher elevations of the Colorado Desert in Southern California.	Similar to Sonoran but with a more robust build.
Arizona Black Rattlesnake	Crotalus cerberus	2.5-4 ft	Woodlands and high mountain regions of central and northern Arizona.	Dark black or charcoal, with subtle banding and speckles, body color darkens with age.
Timber Rattlesnake	Crotalus horridus	3-5 ft	Deciduous forests, often near rocky hillsides and wetlands, in the Eastern U.S.	Thick, yellowish, or grayish body with dark, chevron-shaped crossbands
Tiger Rattlesnake	Crotalus tigris	2-3 ft	Rocky hillsides and mountainous regions of the Southwestern U.S., especially in Arizona.	Small head, smallest among all rattlesnakes, with unique crossband pattern on their anterior side.
Prairie Rattlesnake	Crotalus viridis	3-4 ft	Grasslands, prairies, and deserts of Canada to the central U.S. and Mexico in the south	Rounded snout, with light and dark blotches and a light stripe behind the eyes.
Hopi Rattlesnake	C. v. nuntius	1.5-2.5 ft	Desert plateaus and rocky outcrops at elevations of 4,500-9000 ft, mainly in northeastern Arizona.	Light pinkish or tan base color with bands and blotches that are darker down the back
Mojave Rattlesnake	Crotalus scutulatus	3-4.5 ft	Desert regions and scrublands, ranging from the Southwestern U.S. to central Mexico.	Greenish tint with a dark diamond pattern and distinct white bands on the tail.
Huamantlan Rattlesnake	C. s. salvini	4-5 ft	Arid scrublands and dry grasslands of central to southeastern Mexico, from Hidalgo to southwestern Veracruz.	Higher contrast in coloration compared to the main species.
Arizona Ridge-Nosed Rattlesnake	Crotalus willardi	1-2 ft	Wooded slopes and mountainous areas in the Southwestern U.S., particularly Arizona (State Reptile) and New Mexico.	Prominent ridges on the nose, brown body with pale to white stripes.
Del Nido Ridge-Nosed Rattlesnake	C. w. amabilis	1-2 ft	Rocky and semi-arid areas in hihger elevations of north-central Chihuahua, Mexico.	Similar to the other ridge-nosed rattlesnakes, but has a higher number of dorsal blotches.
Southern Ridge-Nosed Rattlesnake	C. w. meridionalis	1-2 ft	Rocky habitats in the south of Durango and southwestern Zacatecas in Mexico.	Similar in appearance to the main species.
New Mexican Ridge-Nosed Rattlesnake	C. w. obscurus	1-2 ft	Dry rocky areas in Southeastern Arizona, southwestern New Mexico, and northwestern Mexico	Similar to the main species, but lacks the facial sripes.
Western Chihuahuan Ridge-Nosed Rattlesnake	C. w. silus	1-2 ft	Rocky and semi-arid regions of eastern Sonora and western Chihuahua in Mexico.	Similar in appearance to the main species.
Eastern Massasauga	Sistrurus catenatus	1.5-2.5 ft	Wetlands and marshy areas, and sometimes in grasslands, in Northeastern and Midwest U.S.	Gray or light brown color with rounded dark blotches and a thick body.
Desert Massasauga	S. t. edwardsii	1.5-2.5 ft	Semi-desert grasslands primarily in the southwestern U.S. and Mexico.	Gray to light brown body and dark blotches or speckles.
Western Massasauga	Sistrurus tergeminus	1.5-3 ft	Southwestern US plains from southeastern Colorado to central Texas and northern Mexico.	Similar to Eastern but often paler, blotches contrast distinctly with paler ground color.
Pygmy Rattlesnake	Sistrurus miliarius	1-2 ft	Mixed woodlands, coastal scrub, and near lakes and marshes in Southeastern U.S.	Grayish base color with a reddish-brown stripe down the back and dark blotches.
Dusky Pygmy Rattlesnake	S. m. barbouri	1-2 ft	Wetlands, forests, and occasionally urban areas in the Southeastern U.S.	Dark, dusky, with an orange stripe down the back. Smaller than other pygmy species.
Western Pygmy Rattlesnake	S. m. streckeri	1-2 ft	Woodlands, rocky fields, and grasslands across the central and southeastern US.	Similar to Dusky but with more distinct blotches
Midget Faded Rattlesnake	Crotalus concolor	1.5-2.5 ft	High deserts and rocky slopes, particularly in Colorado, Wyoming, and Utah.	More slender than other rattlesnakes with a light body and faint markings.
Speckled Rattlesnake	Crotalus mitchellii	2-4 ft	Rocky slopes, chapparals, and deserts of Southwestern US and northwestern Mexico.	Light color with darker speckles, often blends with sandy environments
El Muerto Island Speckled Rattlesnake	C. m. muertensis	1.5-2 ft	Arid and rocky habitats of the El Muerto Island in Mexico	Similar to the main species, but smaller and more slender.
Black-Tailed Rattlesnake	Crotalus molossus	2.5-4 ft	Forested hillsides and rocky areas in the Southwestern U.S., mainly Arizona, Texas, and New Mexico.	Black tail with a yellowish to olive body and a distinctive stripe over the eyes.
Mexican Black-Tailed Rattlesnake	C. m. nigrescens	3-4.5 ft	Rocky hillsides and arid montane forests throughout Mexico.	Dark body with a distinct black tail and prominent rattle.
Oaxacan Black-Tailed Rattlesnake	C. m. oaxacus	3-4.5 ft	Rocky outcrops and semi-arid regions in Oaxaca, Mexico	Similar to the main species, but darker, with less pronounced patterns.
Red Diamond Rattlesnake	Crotalus ruber	2.5-5 ft	Chaparral and coastal sage scrub, mainly in Southern California and Baja California.	Red diamond patterns with white borders on a pale to reddish-brown body.
Cedros Island Red Diamond Rattlesnake	C. r. exsul	2.5-5 ft	Various dry habitats in the Cedros Island in Mexico	Similar in appearance to the main species.
San Lucan Red Diamond Rattlesnake	C. r. lucasensis	2.5-5 ft	Dry and rocky habitats in lower Baja California, particularly in Cabo San Lucas, Mexico.	Similar in appearance to the main species, but endemic to its own range.
San Lorenzo Island Red Diamond Rattlesnake	Crotalus lorenzoensis	1.5-3 ft	Arid and rocky habitats of the San Lorenzo Island in Mexico.	Previously a subspecies of red diamond rattlesnake, so it looks similar, but smaller.
Northwestern Neotropical Rattlesnake	Crotalus culminatus	4-6 ft	Rocky outcrops and tropical forests in Central and Southern mexico.	Light brown to gray body with diamond-shaped markings and a large head.
Mexican West Coast Rattlesnake	Crotalus basiliscus	3-6 ft	Tropical deciduous forests and arid regions along the western coast of Mexico.	Greenish tint with a dark diamond pattern and white bands on the tail.
Campbell’s Rattlesnake	Crotalus campbelli	2-3 ft	Rocky and semi-arid areas in northern Mexico.	Reddish-brown or orange body with dark, narrow crossbands.
Santa Catalina Rattlesnake	Crotalus catalinensis	1.5-2.5 ft	Endemic to the rocky environments of Santa Catalina Island in Mexico.	Very limited range, nearly patternless, light gray or blue-gray
Western Dusky Rattlesnake	Crotalus armstrongi	1.5-2 ft	Rocky outcrops and deserts of Western Mexico.	Tan with dark, narrow crossbands, and a dark band extending from the eyes
Baja Rattlesnake	Crotalus enyo	2.5-3 ft	Arid desert areas of Baja California, northwestern Mexico	Grayish or light brown with dark crossbands; has a small head with large eyes.
Cerralvo Island Rattlesnake	C. e. cerralvensis	1.5-2.5 ft	Arid and rocky habitats of Isla Ceralvo, Mexico	Has the largest head to body ratio among all enyo species
Rosario Rattlesnake	C. e. furvus	2.5-3.5 ft	Extremely rocky, desert areas in Baja California.	Similar to Baja rattlesnakes, but often darker in color.
Guerreran Long-tailed Rattlesnake	Crotalus ericsmithi	1.5-2.5 ft	Rocky and semi-arid regions in Guerrero, Mexico.	Has a longer tail than other rattlensakes, with a shorter rattle.
Mexican Small-Headed Rattlesnake	Crotalus intermedius	1.5-2 ft	Dry pine-oak woodlands, cloud forests, and deserts of central to southern Mexico.	Has a small head, with a pale gray body having small blotches with dark borders
Oaxacan Small-Headed Rattlesnake	C. i. gloydi	1.5-2 ft	Rocky outcrops and semi-arid regions of Oaxaca, Mexico.	Similar to the main species, with unique head scale formations.
Omilteman Small-Headed Rattlesnake	C. i. omiltemanus	1.5-2 ft	Rocky and semi-arid regions in Guerrero, Mexico	Similar to the main species; identified by its unique scale count.
Autlan Rattlesnake	Crotalus lannomi	1.5-2 ft	Semi-arid and rocky regions in Colima and Jalisco states, Mexico	Similar to the long-tailed rattlesnake, but slightly heavier and larger.
Mottled Rock Rattlesnake	Crotalus lepidus	1.5-2.5 ft	Rocky slopes and high elevation areas, particularly in the southwestern U.S.	Base color resembles the rocks in its habitat, with darker chevron bands.
Banded Rock Rattlesnake	C. l. klauberi	1.5-2.5 ft	Mountainous regions with rocky substrates in the Southwestern U.S. and northern Mexico.	Gray or blue-gray with darker crossbands, bands may be pink or brown
Durango Rock Rattlesnake	C. l. maculosus	1.5-2.5 ft	Humid chaparral and pine-oak forests in Northwestern Mexico.	Pale gray robust body with dark crossbands, and a rounded head
Veracruz Neotropical Rattlesnake	Crotalus mictlantecuhtli	4-6 ft	Tropical forests and savannas in Veracruz, Mexico	Pale brown or gray with darker diamond-shaped patterns.
San Esteban Island Black-Tailed Rattlesnake	Crotalus estebanensis	3-4.5 ft	Deserts and xeric shrublands in San Esteban Island, Mexico	Pale brown or reddish body with a black tail.
Tamaulipan Rock Rattlesnake	Crotalus morulus	1.5-2.5 ft	Grasslands and various arid montane areas in Mexico and Central America	Grayish or brown with dark, irregular crossbands.
Western Rattlesnake/ Northern Pacific Rattlesnake	Crotalus oreganus	3-4.5 ft	Forests and grasslands along the Pacific coast from northern California to British Columbia.	Dark blotches on a brown to black body, and dark stripes running from the eyes to the jaw.
Grand Canyon Rattlesnake	C. o. abyssus	2-3 ft	Rocky areas within and around the Grand Canyon region.	Pale body with a reddish tint, with dark blotches and crossbands near the tail.
Coronado Island Rattlesnake	C. o. caliginis	1.5-2.5 ft	Arid and rocky habitats of the South Coronado Island in Mexico	Pale with dark crossbands.
Southern Pacific Rattlesnake	Crotalus helleri	2-5 ft	Coastal mountains and desert fringes of Southern California	Similar to Northern Pacific, but its patterns are more distinctly diamond-shaped.
Great Basin Rattlesnake	Crotalus lutosus	2.5-4 ft	High desert regions and arid grasslands across the Great Basin in the U.S.	Light brown or gray with darker blotches, more uniform color than other diamondbacks
Eastern Black-Tailed Rattlesnake	Crotalus ornatus	2.5-4 ft	Arid habitats of Texas and eastern to central New Mexico.	Similar to Black-tailed but with a range more to the east, darker tail
Horsehead Island Rattlesnake	Crotalus polisi	1-2 ft	Arid and rocky habitats of the Isla Cabeza de Caballo (Head of the Horse), Mexico.	Light gray or tan with dark crossbands, often more in number around the tail.
Mexican Lancehead Rattlesnake	Crotalus polystictus	2-3 ft	Plateau of Central Mexico at elevations between 4,760 and 8,530 ft.	Light brown, yellow, or gray with dark, triangular ‘lancehead’ markings.
Twin-Spotted Rattlesnake	Crotalus pricei	1.5-2.5 ft	Mountainous, wooded areas in the Southwestern U.S., especially from Arizona, to northern Mexico.	Gray, to brown or reddish-brown, with a pair of spots running down the back.
Eastern Twin-Spotted Rattlesnake	C. p. miquihuanus	1.5-2 ft	Forested and semi-arid areas of Eastern Mexico	Paler with smaller, lighter spots than those on the main species.
Mexican Pygmy Rattlesnake	Crotalus ravus	1-2 ft	Arid and semi-arid areas in northern and central Mexico.	A gray body with dark spots and light crossbands.
Oaxacan Pygmy Rattlesnake	C. r. brunneus	1.5-2.5 ft	Rocky outcrops and semi-arid regions in Oaxaca state, Mexico	Distinguished from other pygmies by its higher number of tail bands (5-8).
Guerreran Pygmy Rattlesnake	C. r. exigus	1.5-2 ft	Rocky and semi-arid habitats in Guerrero in the Sierra Madre del Sur in Mexico.	Pale with dark, irregular crossbands; very small and slender; found in Guerrero region.
Aruba Island Rattlesnake	Crotalus unicolor	2-3 ft	Arid and rocky habitats in the Aruba Islands.	Brown or grayish body with faint crossbands.
Uracoan Rattlesnake	Crotalus vegrandis	2-2.5 ft	The Maturín Savannas and dry forests in Monagas, Venezuela.	Dark body with subdued patterns, giving it a speckled look
Tehuantepec Isthmus Neotropical Rattlesnake	Crotalus ehecatl	3-5 ft	Tropical dry forests in the Isthmus of Tehuantepec, Mexico	Robust, tan to gray body with diamond patterns.
Angel De La Guarda Island Speckled Rattlesnake	Crotalus angelensis	4-6 ft	Arid and rocky terrains in Angel De La Guarda Island, Mexico.	Pale grayish body with dark speckles and blotches
Queretaran Dusky Rattlesnake	Crotalus aquilus	1.5-2 ft	Rocky hillsides and arid areas, Querétaro, Mexico.	Dusky gray or brown with darker, irregular crossbands.
Dusky Rattlesnake	Crotalus triseriatus	1.5-2.5 ft	Pine-oak, and boreal forests, and bunchgrass grasslands at elevations over 9,000 ft in along the southern parts of the Mexican Plateau.	Subdued gray or tan body with pale, irregular crossbands.
Yucatán Neotropical Rattlesnake	Crotalus tzabcan	4-6 ft	Coastal dry forests, pine savannas, and tropical wet forests in the Yucatán Peninsula; may be spotted in open lagoons.	Pale brown with dark diamond-shaped patterns; found in Yucatán Peninsula; robust body.
Tlaloc’s Rattlesnake	Crotalus tlaloci	2-2.5 ft	Semi-arid rocky areas and humid pine-oak forests in central Mexico, at elevations of 6000-7800 ft.	Light brown or gray with dark crossbands; found in forested or semi-arid areas; often with a distinctive pattern.
Totonacan Rattlesnake	Crotalus totonacus	4-5.5 ft	Coastal plains of the Gulf of Mexico.	Yellowish to reddish-brown with darker diamond patterns and a black patch on the tail.
Cross-Banded Mountain Rattlesnake	Crotalus transversus	1-1.5 ft	Temperate boreal forests at elevations over 9,500 ft, along the Trans-Mexican Volcanic Belt in south-central Mexico.	Grayish or brown with distinct crossbands; has a long tail that forms about 10% of its total length.
Panamint Rattlesnake	Crotalus stephensi	2.5-4 ft	Dry mountain areas and rocky outcrops in the Panamint Range of California.	Similar to Red Diamond but with less pronounced patterning, a more isolated range
Tancitaro Rattlesnake	Crotalus tancitarensis	1.5-2.5 ft	Pine-fir forests at elevations over 10,000 ft, in the Cerro Tancítaro mountain, Mexico.	Pale gray or brown with dark crossbands; robust body; found in rocky, arid habitats.
Louse Island Speckled Rattlesnake	Crotalus thalassoporus	1-2 ft	Arid and rocky habitats of Louse Island in baja California, Mexico.	The base color matches the rock and dirt of its habitat, with speckles and blotches.
Middle American Rattlesnake	Crotalus simus	4-6 ft	Dry tropical forests, arid scrublands, and thorn woodland from southwestern Mexico to west-central Costa Rica	Pale with dark crossbands; slightly raised dorsal scales gives it a rough appearance.
Long-Tailed Rattlesnake	Crotalus stejnegeri	1.5-2 ft	Arid and semi-arid mountains and foothills in western Mexico, at elevations of 1,600-3,900 ft.	Identified by its long tail that makes up about 15% of the entire body, and has a small rattle attached.
Tancitaran Dusky Rattlesnake	Crotalus pusillus	1-1.5 ft	Rocky and semi-arid habitats of the Sierra de Coalcomán mountain in west-central Mexico.	Dark gray or brown with faint, irregular crossbands; small; found in dry, rocky areas.
Southwestern Speckled Rattlesnake	Crotalus pyrrhus	3-4 ft	Dry rocky habitats in southwestern U.S. and northwestern Mexico.	Base color resembles the rocks in its habitat, with darker speckles.
South American Rattlesnake	Crotalus durissus	4-6 ft	Coastal savannas in the Guianas.	Yellow or tan, with large diamond patterns. Two stripes start at the base of the head.
Venezuelan Rattlesnake	C. d. cumanensis	4-6 ft	Forested and grassland areas of Venezuela	Similar in appearance to the main species.
Marajoan Rattlesnake	C. d. marajoensis	4-6 ft	Forested and savanna regions, Marajo Island, Brazil.	Similar in appearance to the main species.
Mt. Roraima Rattlesnake	C. d. ruruima	2-4 ft	The slopes of Venezuela’s Mount Roraima and Mount Cariman-Perú.	Similar in appearance to the main species.
Cascavel	C. d. terrificus	4-6 ft	Semi-arid and forested areas, Brazil.	Similar to the main species, but with lighter colored body
Rupunini Rattlesnake	C. d. trigonicus	4-6 ft	Savannas in the Rupunini region, Guyana.	Similar to the main species,but endemic to its own range.
Crotalus durissus maricelae		4-6 ft	Arid and semi-arid areas, Northern Mexico.	Similar in appearance to the main species.

How Dangerous Are Rattlesnakes

Rattlesnakes possess deadly hemotoxic and neurotoxic venom that they inject into their victim through their large fangs. Their venom can paralyze their victim, destroy body tissues (necrosis), and even cause death.

Each year in the US, there are approximately 7,000 to 8,000 snakebite cases, with rattlesnakes being a significant contributor. Despite these numbers, only about 5 cases are fatal. Considering the country’s population of over 300 million, these figures are lower than many might assume. Contrary to popular belief, rattlesnakes are not aggressive and typically only bite when provoked. When they encounter humans, their natural response is to shake their rattles to warn people to stay away.

Still, it is useful to stay familiar with the safety guidelines provided by experts to minimize the chances of an attack.

How Long Do They Live

The majority of rattlesnakes belong to the Crotalus genus, having an average lifespan between 15 and 20 years. On the other hand, pygmy rattlesnakes from the Sistrurus genus live for around 15-16 years.

Do Rattlesnakes Hibernate

Rattlesnakes do not hibernate, but during winter, they go into a period of dormancy called brumation. They brumate in large groups inside caves and burrows. These snakes share these burrows with other snakes and even other animals, like turtles and small mammals. They often return to the same brumation dens for many years.

Like most other snakes, they also aestivate (a period of animal dormancy when the weather is too hot) during the warmest months in some parts of their range.

When Do Rattlesnakes Come Out

They remain active from spring through fall (April-October) in most of their range, mostly emerging at dawn, dusk, and night. However, this may vary depending on the exact location, weather, and temperature of their distribution.

What Do They Eat

Rattlesnakes are carnivorous and mostly ambush predators. They feed on lizards, frogs, birds, rodents like mice, squirrels, and other small mammals. Larger species may even hunt larger animals like rabbits and prairie dogs.

The snakes use their excellent eyesight and heat-sensing pits to catch their prey. Once the snake bites, the hemotoxins immobilize the prey so the snake can swallow it whole. Adult rattlesnakes feed only about once every two weeks.

How Do They Reproduce

Rattlesnakes are ovoviviparous, meaning the females carry the eggs inside their bodies and then give birth to live young. The gestation period can vary from one species to another but typically ranges between 3 and 6 months. 

Depending on the species and their habitat range, mating can occur at any time, from spring to fall. Males may fight to gain mating rights. This behavior is more pronounced in some species, with the timber rattlesnakes being renowned for the males’ ‘combat dances.’

The baby snakes are born with fully developed and functioning venom glands and fangs. The females stay with their brood for several weeks. The young snakes take 2-3 years or more to mature.

Do They Have Predators

Newborn snakes are often preyed upon by animals such as raccoons, wildcats, badgers, coyotes, and skunks, as well as birds like owls, ravens, eagles, and even kingfishers. Larger snakes like kingsnakes, indigo snakes, and even adult rattlesnakes.

The common kingsnake is immune to rattlesnake venom and can prey upon even the adults.

Are Rattlesnakes Endangered

Though most species are considered Least Concern by the IUCN, some, like the eastern massasauga and timber rattlesnake, are on the endangered species list in states like Illinois, Indiana, Ohio, and New York. Rattlesnakes are protected by law in most places where they live, so it may be illegal to kill them. 

FAQ