Articles on this page are available in 1 other language: Spanish (7) (learn more)

Overview

Brief Summary

Notes

Types: none designated (McDiarmid et al., 1999).

Type-locality: "the Upper Missouri" (Valley, USA). Smith and Taylor (1950) proposed an emendation to "Gross, Boyd County, Nebraska." (McDiarmid et al., 1999).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Mohammadi, Shabnam

Source: Snake Species of the World

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Common Names

Prairie rattlesnake

Western rattlesnake

Plains rattlesnake

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Mohammadi, Shabnam

Source: Snake Species of the World

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Distribution

National Distribution

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Global Range: (200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)) As defined by Crother et al. (2003), following congruence of Pook et al. (2000), Ashton and de Queiroz (2001), and Douglas et al. (2002), this species encompasses only the ranges of subspecies viridis and nuntius of traditionally defined C. viridis. In other words, the range extends from southern Alberta and southern Saskatchewan to the northern fringe of northern central Mexico, west to Idaho, Wyoming, Colorado, and extreme eastern Arizona, east to the Dakotas, western Iowa, Nebraska, central Kansas, central Oklahoma, and western and central Texas (Stebbins 2003, Campbell and Lamar 2004). The ranges and relationships of Crotalus oreganus and Crotalus viridis in the Four Corners region and in northwestern Colorado need further clarification (Hammerson 1999; Brennan and Holycross, 2004, Herpetol. Rev. 35:190-191). Elevational range extends from about 100 meters near the Rio Grande (Campbell and Lamar 2004) to at least 2,895 meters (9,500 feet) in Colorado (Hammerson 1999).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Range Description

As defined by Crother et al. (2003), following congruence of Pook et al. (2000), Ashton and de Queiroz (2001), and Douglas et al. (2002), this species encompasses only the ranges of subspecies viridis and nuntius of traditionally defined C. viridis. In other words, the range extends from southern Alberta and southern Saskatchewan in Canada, to the northern fringe of northern central Mexico, west to Idaho, Wyoming, Colorado, and extreme eastern Arizona, east to the Dakotas, western Iowa, Nebraska, central Kansas, central Oklahoma, and western and central Texas in the United States (Stebbins 2003, Campbell and Lamar 2004). The ranges and relationships of Crotalus oreganus and Crotalus viridis in the Four Corners region and in northwestern Colorado need further clarification (Hammerson 1999; Brennan and Holycross, 2004). Its elevational range extends from about 100 m asl near the Rio Grande (Campbell and Lamar 2004) to at least 2,895 m asl (9,500 feet) in Colorado (Hammerson 1999).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Geographic Range

Crotalus viridis are found across most of the United States west of Texas and the Dakotas. They are also found in northern Mexico and southwest Canada. (Melli, 1999; LaDuc, 2000)

Biogeographic Regions: nearctic (Native )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Continent: Middle-America North-America
Distribution: SW Canada (incl. Alberta, Saskatchewan), W USA (Washington, California, Oregon ?, Montana, South Dakota, New Mexico),  Mexico (Baja California Norte, N Chihuahua, NW Coahuila)  viridis: the Great Plains to the Rocky Mountains and from S Canada to Mexico (N Sonora, N Chihuahua, N Coahuila);
Type locality: “the Upper Missouri”. Restricted to “the prairies between the Cannonball and Heart rivers, within 40 km of the Missouri River in North Dakota” a location far distant from the previous restriction of the type locality to ‘‘vicinity of Kansas City, Missouri’’ (Schmidt, 1953: 226).  nuntius: NE Arizona
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Peter Uetz

Source: The Reptile Database

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Southwestern Canada (southern British Columbia, Alberta and Saskatchewan), western United States, and northern Mexico (Mcdiarmid et al., 1999).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Mohammadi, Shabnam

Source: Snake Species of the World

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Physical Description

The various subspecies of Crotalus viridis may vary slightly in color. Most are greenish gray or greenish brown in color, although members of one subspecies are black with only slight markings. These rattlesnakes have from 33-55 dark blotches on their back, which flatten into rings on the tail, surrounded by lighter markings. Juviniles have similar markings to adults, but may have higher contrast in coloring. All Crotalus viridis have a rattle at the end of their tail, made up of segments of keratin, which knock together to make a rattling sound. The number of segments varies because each time the snake sheds its skin, it gains another segment. Crotalus viridis is generally about 91.5 cm in length, but can be from 89-114 cm. Males and females are dimorphic in that the number of rings on their tails differs. Males tend to have between 6-15 rings, and females tend to have between 4-11 rings.

There are nine subspecies of Crotalus viridis. Crotalus viridis viridis , or Western or Prairie rattlesnake, is the most widespread and is found in most regions of the species. There are eight others which are mostly named for the region they are found in. They are Grand Canyon rattlesnake (Crotalus viridis abyssus), Coronado Island rattlesnake (Crotalus viridis caliginis), Arizona Black rattlesnake (Crotalus viridis ceberus), Midget Faded rattlesnake (Crotalus viridis concolor), Southern Pacific rattlesnake (Crotalus viridis helleri), Great Basin rattlesnake (Crotalus viridis lutosus), and Hopi rattlesnake (Crotalus viridis oreganus). (LaDuc, 2000; Melli, 1999; Herp-edia, 1998; Reptiles and Amphibians of North Dakota, 1999)

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Size

Length: 163 cm

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Type Information

Syntype for Crotalus viridis
Catalog Number: USNM 371
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: No Further Locality Data, California, United States, North America
  • Syntype: Baird, S. F. & Girard, C. 1852. Proc. Acad. Nat. Sci. Philadelphia. 6: 177.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Syntype for Crotalus viridis
Catalog Number: USNM 370
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: No Further Locality Data, California, United States, North America
  • Syntype: Baird, S. F. & Girard, C. 1852. Proc. Acad. Nat. Sci. Philadelphia. 6: 177.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Syntype for Crotalus viridis
Catalog Number: USNM 7762
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: No Further Locality Data, Oregon, United States, North America
  • Syntype: Baird, S. F. & Girard, C. 1852. Proc. Acad. Nat. Sci. Philadelphia. 6: 177.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Montana Valley and Foothill Grasslands Habitat

This taxon can be found in the Montana valley and foothill grasslands ecoregions, along with some other North American ecoregions. This ecoregion occupies high valleys and foothill regions in the central Rocky Mountains of Montana in the USA and Alberta, Canada. The ecoregion the uppermost flatland reaches of the Missouri River drainage involving part of the Yellowstone River basin, and extends into the Clark Fork-Bitterroot drainage of the Columbia River system. The ecoregion, consisting of three chief disjunctive units, also extends marginally into a small portion of northern Wyoming. Having moderate vertebrate species richness, 321 different vertebrate taxa have been recorded here.

The dominant vegetation type of this ecoregion consists chiefly of wheatgrass (Agropyron spp.) and fescue (Festuca spp.). Certain valleys, notably the upper Madison, Ruby, and Red Rock drainages of southwestern Montana, are distinguished by extensive sagebrush (Artemisia spp.) communities as well. This is a reflection of semi-arid conditions caused by pronounced rain shadow effects and high elevation. Thus, near the Continental Divide in southwestern Montana, the ecoregion closely resembles the nearby Snake/Columbia shrub steppe.

A number of mammalian species are found in the ecoregion, including: American Pika (Ochotona princeps), a herbivore preferring talus habitat; Bighorn Sheep (Ovis canadensis), Black-tailed Prairie Dog (Cynomys ludovicianus), who live in underground towns that may occupy vast areas; Brown Bear (Ursos arctos); Hoary Marmot (Marmota caligata), a species who selects treeless meadows and talus as habitat; and the Northern River Otter (Lontra canadensis), a species that can tolerate fresh or brackish water and builds its den in the disused burrows of other animals.

There are six distinct anuran species that can be found in the Montana valleys and foothills grasslands, including: Canadian Toad (Anaxyrus hemiophrys); Western Toad (Anaxyrus boreas); Northern Leopard Frog (Lithobates pipiens); Plains Spadefoot Toad (Spea bombifrons); Columbia Spotted Frog (Rana luteiventris), an anuran that typically breeds in shallow quiet ponds; and the Boreal Chorus Frog (Pseudacris maculata).

Exactly two amphibian taxa occurr in the ecoregion: Long-toed Salamander (Ambystoma macrodactylum), a species who prefers lentic waters and spends most of its life hidden under bark or soil; Tiger Salamander (Ambystoma tigrinum).

Reptilian species within the ecoregion are: Milk Snake (Lampropeltis triangulum), an adaptable taxon that can be found on rocky slopes, prairie and near streambeds; Painted Turtle (Chrysemys picta); Western Plains Garter Snake (Thamnophis radix), a taxon that can hibernate in the burrows of rodents or crayfish or even hibernate underwater; Yellow-bellied Racer (Coluber constrictor); Spiny Softshell Turtle (Apalone spinifera); Western Terrestrial Garter Snake (Thamnophis elegans); Rubber Boa (Charina bottae); Western Skink (Plestiodon skiltonianus); and the Western Rattlesnake (Crotalis viridis).

The ecoregion supports endemic and relict fisheries: Westslope Cutthroat Trout (Oncorhynchus clarki lewisi), Yellowstone Cutthroat Trout (Oncorhynchus clarkii bouvieri), and fluvial Arctic Grayling (Thymallus arcticus), a relict species from past glaciation.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© C. Michael Hogan & World Wildlife Fund

Supplier: C. Michael Hogan

Trusted

Article rating from 1 person

Average rating: 5.0 of 5

Palouse Grasslands Habitat

This taxon is found in the Palouse grasslands, among other North American ecoregions. The Palouse ecoregion extends over eastern Washington, northwestern Idaho and northeastern Oregon. Grasslands and savannas once covered extensive areas of the inter-mountain west, from southwest Canada into western Montana in the USA. Today, areas like the great Palouse prairie of eastern  are virtually eliminated as natural areas due to conversion to rangeland. The Palouse, formerly a vast expanse of native wheatgrasses (Agropyron spp), Idaho Fescue (Festuca idahoensis), and other grasses, has been mostly plowed and converted to wheat fields or is covered by Drooping Brome (Bromus tectorum) and other alien plant species.

the Palouse historically resembled the mixed-grass vegetation of the Central grasslands, except for the absence of short grasses. Such species as Bluebunch Wheatgrass (Elymus spicatus), Idaho Fescue (Festuca idahoensis) and Giant Wildrye (Elymus condensatus) and the associated species Lassen County Bluegrass (Poa limosa), Crested Hairgrass (Koeleria pyramidata), Bottlebrush Squirrel-tail (Sitanion hystrix), Needle-and-thread (Stipa comata) and Western Wheatgrass (Agropyron smithii) historically dominated the Palouse prairie grassland.

Representative mammals found in the Palouse grasslands include the Yellow-bellied Marmot (Marmota flaviventris), found burrowing in grasslands or beneath rocky scree; American Black Bear (Ursus americanus); American Pika (Ochotona princeps); Coast Mole (Scapanus orarius), who consumes chiefly earthworms and insects; Golden-mantled Ground Squirrel (Spermophilus lateralis); Gray Wolf (Canis lupus); Great Basin Pocket Mouse (Perognathus parvus); Northern River Otter (Lontra canadensis); the Near Threatened Washington Ground Squirrel (Spermophilus washingtoni), a taxon who prefers habitat with dense grass cover and deep soils; and the Northern Flying Squirrel (Glaucomys sabrinus), a mammal that can be either arboreal or fossorial.

There are not a large number of amphibians in this ecoregion. The species present are the Great Basin Spadefoot Toad (Spea intermontana), a fossorial toad that sometimes filches the burrows of small mammals; Long-toed Salamander (Ambystoma macrodactylum); Northern Leopard Frog (Glaucomys sabrinus), typically found near permanent water bodies or marsh; Columbia Spotted Frog (Rana luteiventris), usually found near permanent lotic water; Pacific Treefrog (Pseudacris regilla), who deposits eggs on submerged plant stems or the bottom of water bodies; Tiger Salamander (Ambystoma tigrinum), fossorial species found in burrows or under rocks; Woodhouse's Toad (Anaxyrus woodhousii), found in arid grasslands with deep friable soils; Western Toad (Anaxyrus boreas), who uses woody debris or submerged vegetation to protect its egg-masses.

There are a limited number of reptiles found in the Palouse grasslands, namely only: the Northern Alligator Lizard (Elgaria coerulea), often found in screes, rock outcrops as well as riparian vicinity; the Painted Turtle (Chrysemys picta), who prefers lentic freshwater habitat with a thick mud layer; Yellow-bellied Racer (Chrysemys picta); Ringneck Snake (Diadophis punctatus), often found under loose stones in this ecoregion; Pygmy Short-horned Lizard (Phrynosoma douglasii), a fossorial taxon often found in bunchgrass habitats; Side-blotched Lizard (Uta stansburiana), frequently found in sandy washes with scattered rocks; Southern Alligator Lizard (Elgaria multicarinata), an essentially terrestrial species that prefers riparian areas and other moist habitats; Pacific Pond Turtle (Emys marmorata), a species that usually overwinters in upland habitat; Western Rattlesnake (Crotalus viridis), who, when inactive, may hide under rocks or in animal burrows; Night Snake (Hypsiglena torquata); Western Skink (Plestiodon skiltonianus), who prefers grasslands with rocky areas; Western Terrestrial Garter Snake (Thamnophis elegans), found in rocky grasslands, especially near water; Rubber Boa (Charina bottae).

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© C. Michael Hogan & World Wildlife Fund

Supplier: C. Michael Hogan

Trusted

Article rating from 2 people

Average rating: 3.0 of 5

Comments: This snake inhabits a wide diversity of habitats, from prairies and arid basins to wooded mountains (Lowe et al. 1986, Degenhardt et al. 1996, Hammerson 1999, Werler and Dixon 2000, Stebbins 2003, Campbell and Lamar 2004, Werner et al. 2004). It is primarily terrestrial but sometimes climbs into trees or shrubs. When inactive, it occupies mammal burrows, crevices, caves, or similar secluded sites. Pregnant females may congregate near the winter den until parturition (Gannon and Secoy 1985, Graves and Duvall 1992).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat and Ecology

Habitat and Ecology
This snake inhabits a wide diversity of habitats, from prairies and arid basins to wooded mountains (Lowe et al. 1986, Degenhardt et al. 1996, Hammerson 1999, Werler and Dixon 2000, Stebbins 2003, Campbell and Lamar 2004, Werner et al. 2004). It is primarily terrestrial but sometimes climbs into trees or shrubs. When inactive, it occupies mammal burrows, crevices, caves, or similar secluded sites. Pregnant females may congregate near the winter den until parturition (Gannon and Secoy 1985, Graves and Duvall 1992).

Systems
  • Terrestrial
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Crotalus viridis are found mostly in grasslands and prairies, and in brush. Various subspecies can be found in woods, forests, caves, rock ledges, and alongside streams. Crotalus viridis avoids desert. (LaDuc, 2000; Melli, 1999; Crotalus viridis viridis, 1999)

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: savanna or grassland ; chaparral ; forest

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Various habitats from sea level to over 2500 m elevation (McDiarmid et al., 1999).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Mohammadi, Shabnam

Source: Snake Species of the World

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Migration

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

In some populations, individuals may migrate up to several km (up to 11 km or more in Wyoming) between winter den and summer range (Duvall et al. 1985, 1990).

Exhibits fidelity to winter den site.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Trophic Strategy

Comments: Diet includes mainly small mammals; also birds, lizards, and rarely amphibians (see Ernst 1992). Juveniles in some regions prey mostly on lizards rather than on small mammals.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Food Habits

Crotalus viridis eat small mammals, ground nesting birds, amphibians, and reptiles, including sometimes other snakes. They locate their prey by using their tongue to sense in airborn chemicals given off by the prey. Then they rapidly strike out at them, biting them with their fangs, then letting them go quickly. Venom is released from their fangs when the snakes strike. It works to immobilize the prey, which the snake then tracks and eats. The venom also works to destroy tissue and help with the digestion of bulkier prey.

Their venom is very deadly. Crotalus viridis use from 20-55% of their stored venom when they bite a small mammal such as a mouse. This is approximately 300 times the amount of venom needed to kill that animal. Venom is stored in glands which are connected to the hollow fangs. Venom is the means used to kill the prey, as the bite of the fangs alone would not usually result in death. The fangs are covered by thin tissue and fold back against the roof of the mouth when the mouth is closed.

During early spring and late fall when the weather is warm, Crotalus viridis hunts during the day. When the weather gets hotter, Crotalus viridis tends to seek shelter during the day and wait until night when it is cooler to hunt. (Greene, 1997; Jacobs, 1999; Kardong et. al., 1998; Kardong, 1996; Melli, 1999; Reptiles and Amphibians of North Dakota, 1999)

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Associations

Predation

The predators of Crotalus viridis include some predatory birds such as red-tailed hawks. When Crotalus viridis senses a predator, it makes a rattling sound to warn it. Smaller snakes tend to wait until the predator is closer to begin rattling, as do pregnant females.

Anti-predator Adaptations: cryptic

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Known prey organisms

Crotalus viridis preys on:
Spermophilus washingtoni
Tamias dorsalis
Tamias merriami

This list may not be complete but is based on published studies.
Creative Commons Attribution 3.0 (CC BY 3.0)

© SPIRE project

Source: SPIRE

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Population Biology

Number of Occurrences

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: This species is represented by a very large number of occurrences. On a range-wide scale, Campbell and Lamar (2004) mapped hundreds of collection sites (see also dot maps in Degenhardt et al. 1996 and Hammerson 1999).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Global Abundance

100,000 to >1,000,000 individuals

Comments: Adult population size is unknown but certainly exceeds 100,000.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

General Ecology

Mortality tends to be high in first-year young.

May congregate at hibernation dens; formerly many den sites harbored up to several hundred snakes, but most of these populations have been decimated by humans.

Primary predators include humans, various mammalian carnivores, raptors, kingsnakes, whipsnakes, and racers.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Cyclicity

Comments: Mostly diurnal in cool weather, active in evening and at night in hot summer weather (morning and late afternoon in far north, Gannon and Secoy 1985). Active primarily from about late March or April to October or November over most of range.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life Expectancy

Lifespan/Longevity

Average lifespan

Status: captivity:
24.1 years.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Lifespan, longevity, and ageing

Maximum longevity: 24.1 years (captivity)
Creative Commons Attribution 3.0 (CC BY 3.0)

© Joao Pedro de Magalhaes

Source: AnAge

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Reproduction

Mating occurs mostly from mid-summer to early fall, mainly in late summer in central U.S. (Aldridge, 1993, J. Herpetol. 27:481-484), occasionally in spring. Young are born usually in August-October. Litter size increases with female size (average 5 where body size is small, maximum about 25 in the largest females where body size is large. Individual adult females may not give birth in some years, probably depending on nutritional status; interval between litters was 2 or more years in Wyoming (Graves and Duvall 1992). Requires several years to reach sexual maturity in areas with short growing season. Pregnant females may congregate in small area.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Crotalus viridis mate between March and May. They have internal fertilization; males have a hemipenis which they use for copulation. Females give birth to between 4-21 live young in late summer or early fall. The babies are able to take care of themselves immediately and require no parental care. They are from 22-28 cm long when born and are already venomous. They reach sexual maturity after three years. Males may compete for females during mating season; however, body size of males does not seem to be a trait that contributes to mating success. In areas where females are scarce, males spend more time searching for females, and are not generally observed fighting over females.

(Duvall, 1997; Fitch, 1998; Melli, 1999; Reptiles and Amphibians of North Dakota, 1999; Crotalus viridis viridis, 1999)

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Crotalus viridis

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

National NatureServe Conservation Status

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N5 - Secure

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2007

Assessor/s
Frost, D.R., Hammerson, G.A. & Santos-Barrera, G.

Reviewer/s
Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)

Contributor/s

Justification
Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

There are currently no conservation measures being taken for Crotalus viridis because their existence is not considered threatened. (Melli, 1999)

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Global Short Term Trend: Relatively stable (=10% change)

Comments: Currently, extent of occurrence, area of occupancy, and number of subpopulations, and population size probably are relatively stable or declining at a rate of less than 10 percent over 10 years or three generations.

Global Long Term Trend: Relatively stable to decline of 50%

Comments: Some local populations have declined or disappeared as a result of historical killing of snakes at dens (Hammerson 1999, Ernst and Ernst 2003).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Population

Population
This species is represented by a very large number of occurrences. On a range-wide scale, Campbell and Lamar (2004) mapped hundreds of collection sites (see also dot maps in Degenhardt et al. 1996 and Hammerson 1999). The adult population size is unknown but certainly exceeds 100,000. Some local populations have declined or disappeared as a result of historical killing of snakes at dens (Hammerson 1999, Ernst and Ernst 2003). Currently, its extent of occurrence, area of occupancy, and number of subpopulations, and population size are probably relatively stable or declining at a rate of less than 10% over 10 years or three generations.

Population Trend
Stable
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Threats

Degree of Threat: Medium

Comments: No major threats are known. Locally, populations have been eliminated or depleted as a result of killing at dens and loss/degradation of habitat by residential, commercial, and agricultural development (Hammerson 1999).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Major Threats
No major threats are known. Locally, populations have been eliminated or depleted as a result of killing at dens and loss/degradation of habitat by residential, commercial, and agricultural development (Hammerson 1999).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed

Comments: Many occurrences are in protected areas.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation Actions

Conservation Actions
Many occurrences of this species are in protected areas.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Economic Uses

Comments: Venomous.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Economic Importance for Humans: Negative

The only adverse affect that Crotalus viridis can have on humans is that they may bite an individual that provokes them. Their venom can cause injury and death. (Jacobs, 1999)

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Economic Importance for Humans: Positive

Crotalus viridis help to control populations of rodents and other animals that they feed on.

  • Fitch, H. 1998. The Sharon Springs roundup and prairie rattlesnake demography. Transactions of the Kansas Academy of Science, 101(3-4): 101-113.
  • Greene, H. 1997. Snakes. Berkely: University of California Press.
  • Melli, J. 1999. "San Diego Natural History Museum Field Guide: Crotalus Viridis" (On-line). Accessed March 23, 2000 at http://www.sdnhm.org/fieldgude/herps/crot-viridis.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Crotalus viridis

Crotalus viridis (Common names: prairie rattlesnake,[2] western rattlesnake,[3] plains rattlesnake,[4] and others) is a venomous pit viper species native to the western United States, southwestern Canada, and northern Mexico. Currently, two subspecies are recognized, including the nominate subspecies described here.[2]

Taxonomy[edit]

The taxonomic history of this species is convoluted. Previously, seven other C. viridis subspecies were also recognized, including C. v. abyssus, C. v. caliginis, C. v. cerberus, C. v. concolor, C. v. helleri, C. v. lutosus and C. v. oreganus. However, in 2001 Ashton and de Queiroz described their analysis of the variation of mitochondrial DNA across the range of this species. Their results agreed broadly with those obtained by Pook et al. (2000). Two main clades were identified, east and west of the Rocky Mountains, which they argued were actually two different species: on the one hand C. viridis, including the conventional subspecies C. v. viridis and C. v. nuntius, and on the other C. oreganus, including all the other traditional subspecies of C. viridis. The authors retained the names of the traditional subspecies, but emphasized the need for more work to be done on the systematics of C. oreganus.[5][6][7]

Geographic range[edit]

They are found in North America over much of the Great Plains, the eastern foothills and some intermontane valleys of the Rocky Mountains, from southwestern Canada through the United States to northern Mexico. In Canada, they occur in Alberta and Saskatchewan; in the USA in eastern Oregon, eastern Washington, southern Idaho, most of Montana (where it is one of 10 snake species and the only venomous one), North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, Texas, New Mexico, extreme eastern Arizona, and in Mexico in northern Coahuila and northwestern Chihuahua. Its vertical range is from 100 m (330 ft) near the Rio Grande to over 2,775 m (9,104 ft) in elevation in Wyoming.[5]

Wright and Wright (1957) and Klauber (1997) both mention Utah as within the range of this species, including maps showing it confined to the extreme southeastern part of the state.[4][8] The type locality is described as "the Upper Missouri [Valley, USA]". An emendation was proposed by H.M. Smith and Taylor (1950) to "Gross, Boyd County, Nebraska."[1]

Description[edit]

This species commonly grows to more than 100 cm (3.3 ft) in length. The maximum recorded size is 151.5 cm (4.97 ft). In Montana, specimens occasionally exceed 120 centimetres (3.9 ft) in length; the species reaches its maximum size in this region. One of the most characteristic features is the presence of three or more, usually four, internasal scales.[5]

Identification characteristics will vary depending on which subspecies is encountered. Generally, western rattlesnakes are usually lightly colored in hues of brown. Patches of dark brown are often distributed in a dorsal pattern. A color band may be seen at the back of the eye. The western rattlesnake group carries the distinctive triangle-shaped head and pit sensory organs on either side of the head. A key characteristic that can help differentiate a western rattlesnake from other rattlesnakes is the presence of two internasals contacting the rostral.[9]

Habitat[edit]

Habitat characteristics can vary depending on subspecies and range. Generally, western rattlesnakes occupy areas with an abundant prey base. Many subspecies occupy somewhat rocky areas with outcrops serving as den sites. Western rattlesnakes have also been known to occupy burrows of other animals. They seem to prefer dry areas with moderate vegetation coverage. Vegetation cover will vary depending on region and subspecies.[9]

Diet[edit]

Western rattlesnakes, because of their expansive distribution, have a wide array of prey. Generally, this species prefers small mammals, such as ground squirrels, ground nesting birds, mice, rats, small rabbits and prairie dogs. They will occasionally feed on amphibians and reptiles, and sometimes even other snakes. This is more commonly seen in juvenile snakes.[9]

Reproduction[edit]

Western rattlesnakes are viviparous and can produce from one to 25 young per reproduction event. The average number of young ranges from four to 12, but can vary greatly due to availability of food and environmental conditions. Males may compete for females during the breeding season, but Western rattlesnake females may not necessarily breed every year.[10] They give birth in late summer or early fall, being their breed 22-28 cm long, without the need for parental care. In addition, their pups are toxic as soon as they are born. They reach sexual maturity at three years of age. It is also common for females to give birth at communal den sites with the young born between August and October.[9][11]

Behavior[edit]

In a defensive posture.

Western rattlesnakes live on the land, but it can sometimes climb in trees or bushes. Some even rest in crevices or caves. They are typically active diurnally in cooler weather and nocturnally during hot weather C. viridis. This species complex is equipped with powerful venom, using about 20-55 percent of venom in one bite, and will defend themselves if threatened or injured. As with other rattlesnake species, western rattlesnakes will rapidly vibrate their tails, which produces a unique rasping sound to warn intruders.[11]

The toxin of the Western Rattlesnake is a complexly structured mixture of different proteins with enzymes such as proteases and peptidases found among them. Besides the hemotoxine and its tissue destructive effect, the poison also has neurotoxic properties.[12]

Common names[edit]

Common names for this species include: prairie rattlesnake,[2][4] western rattlesnake,[3] plains rattlesnake, black rattler, prairie rattler, common rattlesnake, confluent rattlesnake, Great Basin rattlesnake, large prairie rattlesnake, Missouri rattlesnake, rattlesnake of the prairies, spotted rattlesnake, western Pacific Rattlesnake.[4]

Conservation status[edit]

This species is classified as Least Concern on the IUCN Red List of Threatened Species (v3.1, 2001).[13] Species are listed as such due to their wide distribution, presumed large population, or because they are unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend was stable when assessed in 2006.[14]

Subspecies[edit]

The Crotalus viridis nuntius, Hopi rattlesnake (Klauber, 1935),[2] inhabits the United States from northeastern and north-central Arizona, from the New Mexico border to Cataract Creek, including the Little Colorado River basin, the southern section of the Apache Indian Reservation, the Hopi Reservation, and the Coconino Plateau from the southern rim of the Grand Canyon to US Highway 66 in the south.[8]

The Crotalus viridis viridis, prairie rattlesnake (Rafinesque, 1818),[2] inhabits the North American Great Plains from the Rocky Mountains to 96° W and from southern Canada to extreme northern Mexico, including southwestern Saskatchewan, southeastern Alberta, eastern Washington, Idaho in the Lemhi Valley, Montana east of the higher Rockies, southwestern North Dakota, west, central and extreme southeastern South Dakota, western Iowa, central and western Nebraska, Wyoming except for the Rockies, Colorado, central and western Kansas, Oklahoma, extreme southeastern Utah, northeastern Arizona, New Mexico, western and southwestern Texas, northeastern Sonora, northern Chihuahua, northern Coahuila.[8]

See also[edit]

References[edit]

  1. ^ a b McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).
  2. ^ a b c d e "Crotalus viridis". Integrated Taxonomic Information System. Retrieved 28 November 2006. 
  3. ^ a b "Crotalus". Integrated Taxonomic Information System. Retrieved 28 November 2006. 
  4. ^ a b c d Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates. (7th printing, 1985). 1105 pp. ISBN 0-8014-0463-0.
  5. ^ a b c Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. ISBN 0-8014-4141-2.
  6. ^ Viperidae - Crotalinae - 2001 Publications at Wolfgang Wüster, School of Biological Sciences, Bangor University. Accessed 7 April 2008.
  7. ^ Pook CE, Wüster W, Thorpe RS. 2000. Historical biogeography of the western rattlesnake (Serpentes: Viperidae: Crotalus viridis), inferred from mitochondrial DNA sequence information. Molecular Phylogenetics and Evolution, 15: 269-282. PDF at Wolfgang Wüster, School of Biological Sciences, Bangor University. Accessed 7 April 2008.
  8. ^ a b c Klauber LM. 1997. Rattlesnakes: Their Habitats, Life Histories, and Influence on Mankind. Second Edition. 2 volumes. Reprint, University of California Press, Berkeley. ISBN 0-520-21056-5.
  9. ^ a b c d Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians. Third edition. Houghton McMifflin Company. New York, New York, USA.
  10. ^ C. viridis
  11. ^ a b C. virdis. Accessed 7 October 2009.
  12. ^ Reichl, Franz-Xaver. "Pocket Atlas of Toxicology". chapter: Venoms (Nikol Verlag). ISBN 978-3868200058. 
  13. ^ Crotalus viridis at the IUCN Red List. Accessed 1 September 2007.
  14. ^ 2001 Categories & Criteria (version 3.1) at the IUCN Red List. Accessed 13 September 2007.

Further reading[edit]

  • Ashton KG, de Queiroz A. 2001. Molecular systematics of the Western Rattlesnake, Crotalus viridis (Viperidae), with comments on the utility of the D-Loop in phylogenetic studies of snakes. Molecular Phylogenetics and Evolution 21(2):176-189.
  • Rafinesque, C.S. 1818. Further Accounts of Discoveries in Natural History, in the Western States. American Monthly Magazine and Critical Review 4 (5): 39-42. ("N. Sp. Crotalinus viridis", p. 41.)
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Names and Taxonomy

Taxonomy

Comments: Analysis of historical biogeography based on mtDNA data (Pook et al. 2000) revealed two main clades, one including populations from east and south of the Rocky Mountains and the other consisting of populations west of the Rocky Mountains. The conventionally recognized subspecies do not fully correspond to the phylogenetic pattern, and a review of the systematic status of several populations is needed (Pook et al. 2000).

Ashton and de Queiroz (2001) examined mtDNA variation among 26 populations of C. viridis and also identified two main clades: eastern, including subspecies viridis and nuntius (low levels of genetic divergence), and western, including all other subspecies. However, Ashton and de Queiroz (2001) differed from Pook et al. (2000) with respect to the relationships among members of the western clade, although Ashton and de Queiroz studied only a few individuals from each member of the western clade and stated that the relationships within the western clade are largely unresolved and that none (except possibly cerberus) appeared to deserve recognition as separate evolutionary species. Ashton and de Queiroz suggested that the two main clades be regarded as distinct species, C. viridis (eastern clade) and C. oreganus (western clade). The historical biogeographic scenario described by Ashton and de Queiroz (2001) suggests secondary contact between C. viridis and C. oreganus in northern Arizona, southwestern and northwestern Colorado, and southeastern Utah.

Douglas et al. (2002) examined mtDNA variation in C. viridis, with emphasis on the populations on the Colorado Plateau. As did Pook et al. (2000) and Ashton and de Queiroz (2001), they identified eastern and western clades, with the former including the nominal subspecies viridis and nuntius and the latter encompassing all of the other subspecies. Douglas et al. (2002) argued that all of the western subspecies should be recognized as species, but they did not effectively indicate details of distributional relationships in the contact zones among the proposed species. Douglas et al. (2002) concluded that the taxon nuntius should be regarded as a synonym of viridis.

Crother et al. (2003) considered all of the foregoing evidence and adopted the two-species taxonomy (Crotalus oreganus, Crotalus viridis) that is supported by the congruence among all three studies cited above. Campbell and Lamar (2004) also recognized only the two species. However, further clarification of the distributions of C. viridis and C. oreganus is needed, particularly in the contact zones in northern Arizona, southwestern and northwestern Colorado, and southeastern Utah. For example, populations in northwestern Colorado (Moffat County) identified by Douglas et al. (2002) as C. viridis were mapped as C. oreganus concolor by Campbell and Lamar (2004).

Venom characteristics indicate hybridization between C. viridis and C. scutulatus in New Mexico (Glenn and Straight 1990).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!