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Overview

Brief Summary

Notes

Holotype: ANSP 7069 (formerly USNM 5027) (McDiarmid et al., 1999).

Type-locality: None given. Smith and Taylor, 1950, Univ. Kansas Sci. Bull. 33:313-380[353], proposed "Wickenburg, Maricopa County, Arizona" (McDiarmid et al., 1999).

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Common Names

Mojave rattlesnake

Huamantlan rattlesnake

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Distribution

occurs (regularly, as a native taxon) in multiple nations

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National Distribution

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

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Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) The range extends from southern California, southern Nevada, and southwestern Utah south through Arizona (Lowe et al. 1986), southern New Mexico (Degenhardt et al. 1996), western Texas (Tennant 1984), and central Mexico to near the south end of the Mexican Plateau in Puebla and adjacent Veracruz (Stebbins 2003, Campbell and Lamar 2004). Elevational range extends from sea level to around 2,530 meters (8,300 feet) (Stebbins 2003); above 1,800 meters at the southern end of the range (Campbell and Lamar 2004).

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Range Description

The species' range extends from southern California, southern Nevada, and southwestern Utah south through Arizona (Lowe et al. 1986), southern New Mexico (Degenhardt et al. 1996), western Texas (Tennant 1984) in the United States, and central Mexico to near the south end of the Mexican Plateau in Puebla and adjacent Veracruz (Stebbins 2003, Campbell and Lamar 2004). Its elevational range extends from sea level to around 2,530 m asl (8,300 feet) (Stebbins 2003); above 1,800 m asl at the southern end of the range (Campbell and Lamar 2004).
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Continent: Middle-America North-America
Distribution: USA (S California, S Nevada, Arizona, S New Mexico, W Texas),  Mexico (N/E Sonora, Chihuahua, W/S Coahuila, Durango, Zacatecas, San Luis Potosi, S Nuevo Leon, W Tamaulipas, south to S Puebla, Aguascalientes)  kellyi:
Type locality: Needles, CA.  salvini: Mexico (Tlaxcala, Puebla, Hidalgo, WC Veracruz)
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Southwestern USA (southern California, southern Nevada, extreme southwestern Utah, most of Arizona, southern New Mexico, and western Texas) southward through much of Mexico to southern Puebla (McDiarmid et al., 1999).

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Physical Description

Size

Length: 130 cm

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Ecology

Habitat

Sierra Madre Occidental Pine-oak Forests Habitat

This taxon is found in the Sierra Madre Occidental pine-oak forests ecoregion, which boasts some of the richest biodiversity anywhere in North America, and contains about two thirds of the standing timber in Mexico. Twenty-three different species of pine and about 200 species of oak reside within the Sierra Madre Occidental pine-oak forests ecoregion.

Pine-oak forests here typically grow on elevations between approximately 1500 and 3300 meters, and occur as isolated habitat islands in northern areas within the Chihuahuan Desert. Soils are typically deep, where the incline allows soil build-up and derived from igneous material, although metamorphic rocks also form part of the soils in the west and northwest portions of the sierra. Steep-sloped mountains have shaped some portions of the Sierra, while others are dominated by their deep valleys, tall canyons and cliffs. These steep-sided cliffs have thinner soils limiting vegetation to chaparral types; characterized by dense clumps of Mexican Manzanita (Arctostaphylos pungens), Quercus potosina and Netleaf Oak (Q. rugosa). There are also zones of natural pasture, with grasses from the genera Arisitida, Panicum, Bromus and Stevis.

The pine-oak forests gradually transform into an oak-grassland vegetative association. Such communities represent an ecological transition between pine-oak forests and desert grasslands..  Here, species such as Chihuahuan Oak (Quercus chihuahuensis), Shin Oak (Q. grisea),  Q. striatula and Emory Oak (Q. emoryi), mark a transition zone between temperate and arid environments, growing in a sparse fashion and with a well-developed herbaceous stratum resembling xeric scrub. Cacti are also part of these transition communities extending well into the woodlands. Some cacti species such as the Little Nipple Cactus (Mammillaria heyderi macdougalii), Greenflower Nipple Cactus (M. viridiflora), Mojave Mound Cactus (Echinocereus triglochidiatus), and Leding's Hedgehog Cactus (E. fendleri var. ledingii) are chiefly centered in these biotic communities. The dominant vegetation in the northernmost part of the ecoregion in the Madrean Sky Islands includes Chihuahua Pine (Pinus leiophylla), Mexican Pinyon (P. cembroides), Arizona Pine (P. arizonica), Silverleaf Oak (Quercus hypoleucoides), Arizona White Oak (Q. arizonica), Emory Oak (Q. emoryi), Netleaf Oak (Q. rugosa), Alligator Juniper (Juniperus deppeana), and Mexican Manzanita (Arctostaphylos pungens).

This ecoregion is an important area for bird richness and bird endemism. Likewise, virtually all of the ecoregion is included in the Sierra Madre Occidental and trans-mexican range Endemic Bird Area. Endemic bird species include the Thick-billed Parrot (Rhynchopsitta pachyrhyncha EN) which is in danger of extinction, with population estimates as low as 500 pairs; the Tufted Jay (Cyanocorax dickeyi NT), Eared Quetzal (Euptilptis neoxenus NT) and the Green-striped Brush Finch (Buarremon virenticeps). Temperate and tropical influences converge in this ecoregion, forming a unique and rich complex of flora and fauna. Many other birds are found in this ecoregion including the Green Parakeet (Aratinga holochlora), Eared Trogon (Euptilotis neoxenus NT), Coppery-tailed Trogon (Trogon elegans), Grey-breasted Jay (Aphelocoma ultramarina), Violet-crowned Hummingbird (Amazilia violiceps), Spotted Owl (Strix occidentalis NT), and Golden Eagle (Aguila chryaetos).  Some species found only in higher montane areas are the Gould's Wild Turkey (Meleagris gallopavo mexicana), Band-tailed Pigeon (Patagioenas fasciata), Mexican Chickadee (Poecile sclateri) and Hepatic Tanager (Piranga flava).

The Sierra Madre Mantled Ground Squirrel (Spermophilus madrensis NT) is an endemic to the Sierra Madre Occidental pine-oak forests, restricted to southwestern Chihuahua, Mexico. The Mexican Gray Wolf (Canis lupus baileyi) and Mexican Grizzly Bear (Ursus horribilis), although considered by most to be extinct from this ecoregion, once roamed these mountains. Mammals also present include White-tailed Deer (Odocoileus virginianus), American Black Bear (Ursus americanus), Buller’s Chipmunk (Tamias bulleri), endemic Zacatecan Deer Mouse (Peromyscus difficilis), rock Squirrel (Spernophilis variegatus), Zacatecas Harvest Mouse (Reithrodontomys zacatecae) and Coati (Nasua nasua), to set forth a subset of mammals present.

Reptiles are also numerous in this ecoregion. Fox´s Mountain Meadow Snake (Adelophis foxi) is an endemic taxon to the ecoregion, only observed at the type locality at four kilometers east of  Mil Diez, about  3.2 kilometers west of El Salto, in southwestern Durango, Mexico. There are at least six species of rattlesnakes including the Mexican Dusky Rattlesnake (Crotalis triseriatus), Mojave Rattlesnake (C. scutulatus), Rock Rattlesnake (C. lepidus), Western Diamondback Rattlesnake (C. atrox), Twin-spotted Rattlesnake (C. pricei), and Ridgenose Rattlesnakes (C. willardi).  Clark's Spiny Lizard (Sceloporus clarkii) and Yarrow's Spiny Lizard (S. jarrovii), Bunchgrass Lizard (S. scalaris), and Striped Plateau Lizard (S. virgatus) are several of the lizards found in the Sierra Madre Occidental pine-oak forests.

Along springs and streams the Western Barking Frog (Craugastor augusti) and the Tarahumara Frog (Rana tamahumarae) are two anuran taxa occurring in the ecoregion. Other anuran taxa found here include: Bigfoot Leopard Frog (Lithobates megapoda), Northwest Mexico Leopard Frog (Lithobates magnaocularis) and the Blunt-toed Chirping Frog (Eleutherodactylus modestus VU). The Sacramento Mountains Salamander (Aneides hardii) is an endemic salamander found in the Sierra Madre Occidental pine-oak forests, restricted to the Sacramento Mountains, Capitan Mountains, and Sierra Blanca in Lincoln and Otero Counties within southern New Mexico, USA.

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Comments: Habitat is mostly upland desert and lower mountain slopes, including barren desert, grassland, open woodland, and scrubland; in the United States, vegetation in most occupied areas includes creosotebush, palo verde, mesquite, or cacti (Ernst 1992, Ernst and Ernst 2003, Stebbins 2003, Campbell and Lamar 2004). This snake usually is not in broken rocky terrain or densely vegetated areas. In southeastern Arizona, it is more numerous in semidesert grassland than in desert scrub (Mendelson and Jennings 1992). In southern Arizona and adjacent Mexico, it is very common in prairie valleys between forested mountain ranges (Armstrong and Murphy 1979). In the southern part of the range in Mexico, it occurs in open high interior plains, mesquite-grassland, pine-oak, and lava beds with cactus, agave, and grasses (Armstrong and Murphy 1979). In spring, this snake commonly coils under a small tree or shrub in early morning (Armstrong and Murphy 1979). Refuges include animal burrows, spaces under or among rocks, or similar sites.

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Habitat and Ecology

Habitat and Ecology
The species' habitat is mostly upland desert and lower mountain slopes, including barren desert, grassland, open woodland, and scrubland; in the United States, vegetation in most occupied areas includes creosote bush, palo verde, mesquite, or cacti (Ernst 1992, Ernst and Ernst 2003, Stebbins 2003, Campbell and Lamar 2004). This snake usually is not in broken rocky terrain or densely vegetated areas. In southeastern Arizona, it is more numerous in semi-desert grassland than in desert scrub (Mendelson and Jennings 1992). In southern Arizona and adjacent Mexico, it is very common in prairie valleys between forested mountain ranges (Armstrong and Murphy 1979). In the southern part of the range in Mexico, it occurs in open high interior plains, mesquite-grassland, pine-oak, and lava beds with cactus, agave, and grasses (Armstrong and Murphy 1979). In spring, this snake commonly coils under a small tree or shrub in early morning (Armstrong and Murphy 1979). Refuges include animal burrows, spaces under or among rocks, or similar sites.

Systems
  • Terrestrial
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Mojave Desert Habitat

This taxon is found in the Mojave Desert, the smallest of the four North American deserts. While the Mojave lies between the Great Basin Shrub Steppe and the Sonoran Desert, its fauna is more closely allied with the lower Colorado division of the Sonoran Desert. Dominant plants of the Mojave include Creosote Bush (Larrea tridentata), Many-fruit Saltbush (Atriplex polycarpa), Brittlebush (Encelia farinosa), Desert Holly (Atriplex hymenelytra), White Burrobush (Hymenoclea salsola), and Joshua Tree (Yucca brevifolia), the most notable endemic species in the region.

The Mojave’s warm temperate climate defines it as a distinct ecoregion. Mojave indicator species include Spiny Menodora (Menodora spinescens), Desert Senna (Cassia armata), Mojave Indigobush (Psorothamnus arborescens), and Shockley's Goldenhead (Acamptopappus shockleyi). The Mojave supports numerous species of cacti, including several endemics, such as Silver Cholla (Opuntia echinocarpa), Mojave Prickly Pear (O. erinacea), Beavertail Cactus (O. basilaris), and Cotton-top Cactus (Echinocactus polycephalus).

While the Mojave Desert is not so biologically distinct as the other desert ecoregions, distinctive endemic communities occur throughout. For example, the Kelso Dunes in the Mojave National Preserve harbor seven species of endemic insects, including the Kelso Dunes Jerusalem Cricket (Ammopelmatus kelsoensis) and the Kelso Dunes Shieldback Katydid (Eremopedes kelsoensis). The Mojave Fringe-toed Lizard (Uma Scoparia), while not endemic to the dunes, is rare elsewhere. Flowering plants also attract butterflies such as the Mojave Sooty-wing (Pholisora libya), and the widely distributed Painted Lady (Vanessa cardui).

There are a total of eight amphibian species present in the Mojave Desert all of which are anuran species: the endemic Relict Leopard Frog (Lithobates onca); the endemic Amargosa Toad (Anaxyrus nelsoni); Lowland Leopard Frog (Lithobates yavapaiensis); Red-spotted Toad (Anaxyrus punctatus); Southwestern Toad (Anaxyrus microscaphus); Great Basin Spadefoot (Spea intermontana); Great Plains Toad (Anaxyrus cognatus); and the Pacific Treefrog (Pseudacris regilla).

The native range of California’s threatened Desert Tortoise (Gopherus agassizii) includes the Mojave and Colorado Deserts. The Desert Tortoise has adapted for arid habitats by storing up to a liter of water in its urinary bladder. The following reptilian fauna are characteristic of the Mojave region in particular: Gila Monster (Heloderma suspectum NT); Western Banded Gecko (Coleonyx variegatus), Northern Desert Iguana (Dipsosaurus dorsalis), Western Chuckwalla (Sauromalus obesus), and regal horned lizard (Phrynosoma solare). Snake species include the Desert Rosy Boa (Charina trivirgata gracia), Mojave Patchnose Snake (Salvadora hexalepis mojavensis), and Mojave Rattlesnake (Crotalus scutulatus).

Endemic mammals of the ecoregion include the Mojave Ground Squirrel (Spermophilus mohavensis) and Amargosa Vole (Microtus californicus scirpensis); and the California Leaf-nosed Bat (Macrotus californicus).

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Deserts and other xeric vegetational associations from sea level to 2500 m elevation (McDiarmid et al., 1999).

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Migration

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No 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.

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Trophic Strategy

Comments: Eats kangaroo rats, ground squirrels, mice, rabbits, and other small mammals; lizards are also eaten, especially by the young (Tennant 1984). Sometimes eats snakes and spadefoot toads.

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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 large number of occurrences (subpopulations). On a range-wide scale, Campbell and Lamar (2004) mapped hundreds of collection sites.

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Global Abundance

100,000 - 1,000,000 individuals

Comments: Adult population size is unknown but presumably exceeds 100,000. This snake is often locally common (Lowe et al. 1986).

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Life History and Behavior

Cyclicity

Comments: Active almost exclusively at night in some areas, active in morning, late afternoon, and at night in other areas (Tennant 1984). At lower elevations, mainly nocturnal in summer, commonly active in morning and late afternoon in spring and fall; may be active in daytime in summer at higher elevations (Armstrong and Murphy 1979, Ernst 1992).

Has been observed above ground March-November; probably most active from late April or early May through September (Ernst 1992). In Chihuahua, most active in July-August, especially about a month after peak in rainfall (Reynolds, cited by Ernst 1992).

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Life Expectancy

Lifespan, longevity, and ageing

Maximum longevity: 14.4 years (captivity)
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Reproduction

Young are born mainly July-August (often mid-August), sometimes in September. Litter size ranges up to 17 (Herp. Rev. 21:93), average around 8.

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Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Crotalus scutulatus

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 4
Species With Barcodes: 1
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Conservation

Conservation Status

National NatureServe Conservation Status

United States

Rounded National Status Rank: N5 - Secure

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NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

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IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2007

Assessor/s
Mendoza-Quijano, F. & Hammerson, G.A.

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

Comments: Extent of occurrence, area of occupancy, number of subpopulations, and population size probably are relatively stable.

Global Long Term Trend: Increase of 10-25% to decline of 30%

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Population

Population
This species is represented by a large number of occurrences (subpopulations). On a range-wide scale, Campbell and Lamar (2004) mapped hundreds of collection sites. The adult population size is unknown but presumably exceeds 100,000. This snake is often locally common (Lowe et al. 1986). Its extent of occurrence, area of occupancy, number of subpopulations, and population size are probably relatively stable.

Population Trend
Stable
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Threats

Degree of Threat: Low

Comments: No major threats are known.

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Major Threats
No major threats to this species are known.
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Management

Conservation Actions

Conservation Actions
Many occurrences of this species are in protected areas.
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Relevance to Humans and Ecosystems

Benefits

Economic Uses

Comments: Venomous; venom is much more toxic than that of other rattlenakes; often vigorously defensive toward humans; a relatively high percentage of untreated bites result in death in humans (Ernst 1992).

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Wikipedia

Crotalus scutulatus

Crotalus scutulatus (common names: Mohave rattlesnake,[2][3][4] Mojave green,[3]) is a venomous pit viper species found in the deserts of the southwestern United States and central Mexico. It is perhaps best known for its potent neurotoxic venom. Two subspecies are recognized, including the nominate subspecies described here.[5]

Description[edit]

This species grows to an average of less than 100 cm (3.3 ft) in length, with a maximum of 137.3 cm (4.50 ft).[4]

The color varies from shades of brown to pale green depending on the surroundings. The green hue found among Mojave rattlesnakes has led to them being known as "Mojave greens" in some areas. Like C. atrox (the western diamondback rattlesnake), which it closely resembles, C. scutulatus has a dark diamond pattern along its back. With C. scutulatus, the white bands on the tail tend to be wider than the black, while the band width is usually more equal in C. atrox. Additionally, C. scutulatus has enlarged scales on top of the head between the supraoculars, and the light postocular stripe passes behind the corner of the mouth. In C. atrox, the crown is covered in small scales, and the light postocular stripe intersects the mouth.[3][6]


Campbell and Lamar (2004) [4] support the English name "Mohave rattlesnake", but do so with some reluctance because so little of the snake's range lies within the Mojave Desert. They do not support the spelling "Mojave", because the name "Mohave" derives from the Native American term hamakhava.[4]

Geographic range[edit]

C. scutulatus range map

This snake is found in the southwestern United States in southern California, southern Nevada, extreme southwestern Utah, most of Arizona, southern New Mexico, and some of Texas. It also ranges southward through much of Mexico to southern Puebla. It is found in deserts and other areas with xeric vegetation from near sea level to about 2500 m altitude. No type locality is given. Smith and Taylor (1950) proposed "Wickenburg, Maricopa County, Arizona" (USA), while Schmidt (1953) listed the type locality as "Mojave Desert, California" (USA).[1]

Habitat[edit]

Primarily a snake of high desert or lower mountain slopes, it is often found near scrub brush such as mesquite and creosote, but may also reside in lowland areas of sparse vegetation, among cacti, Joshua tree forests, or grassy plains. It tends to avoid densely vegetated and rocky areas, preferring open, arid habitats.[4]

Conservation status[edit]

This species is classified as Least Concern (LC) on the IUCN Red List of Threatened Species (v3.1, 2001).[7] 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 2007.[8]

Behavior[edit]

C. scutulatus is most active from April to September, and brumates alone or in small groups during the winter. Ambush predators, they eat mostly small rodents and lizards. Females bear live young, from two to 17 (average about eight), from July through September.[3][9] Although they have a reputation for being aggressive towards people, such behavior is not described in the scientific literature. Like other rattlesnakes, they will defend themselves vigorously when disturbed.[citation needed]

Venom[edit]

Lethality[edit]

The most common subspecies of Mohave rattlesnake (type A) has venom that is considered to be one of the most debilitating and potentially deadly of all North American snakes, although chances for survival are very good if medical attention is sought as soon as possible after a bite.[10]

Prognosis for bite victims[edit]

In people bitten by venom A Mojave rattlesnakes (those outside the relatively small Venom B area in south-central Arizona), the onset of serious signs and symptoms can be delayed, sometimes leading to an initial underestimation of the severity of the bite. Significant envenomations (as with all snakebites, the quantity of venom injected is highly variable and unpredictable) can produce vision abnormalities and difficulty swallowing and speaking. In severe cases, skeletal muscle weakness can lead to difficulty breathing and even respiratory failure.[11] Contrary to popular belief, fatalities are uncommon.[12][13] This is largely due to the wide availability of antivenom, as any untreated rattlesnake bite is often fatal, especially from larger species or those with more potent venoms.

Antivenom[edit]

Unlike the rattlesnake antivenom used in the United States over the previous 50 years, CroFab antivenom (approved by the US Food and Drug Administration in October 2001) uses Mojave rattlesnake venom A (in addition to venom from three other species) in its manufacture,[14] making it particularly effective for treatment of venom A Mojave rattlesnake bites. Antibodies in CroFab produced by the other three species' venoms effectively neutralize Mojave rattlesnake venom B.

Unique venom characteristics[edit]

All rattlesnake venoms are complex cocktails of enzymes and other proteins that vary greatly in composition and effects, not only between species, but also between geographic populations within the same species. C. scutulatus is widely regarded as producing one of the most toxic snake venoms in the New World, based on LD50 studies in laboratory mice.[15] Their potent venom is the result of a presynaptic neurotoxin composed of two distinct peptide subunits.[16] The basic subunit (a phospholipase A2) is mildly toxic and apparently rather common in North American rattlesnake venoms.[17] The less common acidic subunit is not toxic by itself, but in combination with the basic subunit, produces the potent neurotoxin called “Mojave toxin”. Nearly identical neurotoxins have been discovered in five North American rattlesnake species besides C. scutulatus.[17] However, not all populations express both subunits. The venom of many Mojave rattlesnakes from south-central Arizona lacks the acidic subunit and has been designated “venom B,” while Mojave rattlesnakes tested from all other areas express both subunits and have been designated “venom A” populations.[18]

Venom differences[edit]

Based on median LD50 values in lab mice, venom A from subspecies A Mojave rattlesnakes is more than ten times as toxic as venom B, from type B Mohave green rattlesnakes which lacks Mojave toxin.[19] Medical treatment as soon as possible after a bite is critical to a positive outcome, dramatically increasing chances for survival.[20]

However, venom B causes pronounced proteolytic and hemorrhagic effects, similar to the bites of other rattlesnake species; these effects are significantly reduced or absent from bites by venom A snakes.[11] Risk to life and limb is still significant, as with all rattlesnakes, if not treated as soon as possible after a bite.

Subspecies[edit]

Subspecies[5]Taxon author[5]Common name[9]Geographic range[4]
C. s. salviniGünther, 1895Huamantlan rattlesnakeMexico, from Hidalgo through Tlaxcala and Puebla to southwestern Veracruz
C. s. scutulatus(Kennicott, 1861)Mojave rattlesnakeThe United States from California eastward to west Texas and southward to Querétaro in Mexico

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. ^ Crothier, B.I. et al. 2003. Scientific and standard English names of amphibians and reptiles of North America north of Mexico: Update. Herpetological Review 34:196-203
  3. ^ a b c d Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians. Boston: Houghton Mifflin & Co.
  4. ^ a b c d e f 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.
  5. ^ a b c "Crotalus scutulatus". Integrated Taxonomic Information System. Retrieved 5 January 2007. 
  6. ^ Bush, S.P., M.D. Cardwell. 1999. Mojave rattlesnake (Crotalus scutulatus scutulatus) identification. Wilderness and Environmental Medicine 10:6-9.
  7. ^ Crotalus scutulatus at the IUCN Red List. Accessed 13 September 2007.
  8. ^ 2001 Categories & Criteria (version 3.1) at the IUCN Red List. Accessed 13 September 2007.
  9. ^ a b Klauber LM. 1997. Rattlesnakes: Their Habitats, Life Histories, and Influence on Mankind. Second Edition. First published in 1956, 1972. University of California Press, Berkeley. ISBN 0-520-21056-5.
  10. ^ "Mojave Green snake bites 6-year-old California boy, 42 vials of antivenom needed", Jaslow, Ryan, CBS News, July 10th, 2012, http://www.cbsnews.com/8301-504763_162-57469802-10391704/mojave-green-snake-bites-6-year-old-california-boy-42-vials-of-antivenom-needed/
  11. ^ a b Norris RA. 2004. Venom poisoning by North American reptiles. In 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.
  12. ^ Watt, C.H. 1985. Treatment of poisonous snakebite with emphasis on digit dertotomy. Southern Medical Journal 78:694-699.
  13. ^ Gold, B.S., W.A. Wingert. 1994. Snake venom poisoning in the United States: a review of therapeutic practice. Southern Medical Journal 87:579-589.
  14. ^ Protherics, Inc. 2004. CroFab Crotalidae Polyvalent Immune FAB (Ovine). [Package insert]
  15. ^ Glenn, J.L., R.C.Straight. 1982. The rattlesnakes and their venom yield and lethal toxicity. In: Tu, A. (ed) Rattlesnake Venoms, Their Actions and Treatment. New York: Marcel Dekker, Inc.
  16. ^ Aird, S.D., et al. 1985. Rattlesnake presynaptic neurotoxins: primary structures and evolutionary origin of the acidic subunit. Biochemistry 24:7054-58.
  17. ^ a b Powell, R.L. 2003. Evolutionary Genetics of Mojave Toxin Among Selected Rattlesnake Species (Squamata: Crotalinae). Unpublished PhD dissertation. El Paso: University of Texas.
  18. ^ Glenn, J.L., R.C. Straight. 1978. Mojave rattlesnake Crotalus scutulatus scutulatus venom: Variation in toxicity with geographical origin. Toxicon 16:81-84.
  19. ^ Hendon, R.A., A.L. Bieber. 1982. Presynaptic toxins from rattlesnake venoms. In: Tu, A. (ed) Rattlesnake Venoms, Their Actions and Treatment. New York: Marcel Dekker, Inc.
  20. ^ "Mojave Green snake bites 6-year-old California boy, 42 vials of antivenom needed", Jaslow, Ryan, CBS News, July 10th, 2012, http://www.cbsnews.com/8301-504763_162-57469802-10391704/mojave-green-snake-bites-6-year-old-california-boy-42-vials-of-antivenom-needed/
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Comments: Two geographically distinct venom types are produced by populations in Arizona; biochemical evidence indicates that there is high gene flow between the populations producing the different venom types and that they are conspecific (Wilkinson et al. 1991). Venom characteristics indicate hybridization between C. scutulatus and C. viridis in New Mexico (Glenn and Straight 1990).

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