Sidewinder (Crotalus cerastes) | |
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Death Valley National Park | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Suborder: | Serpentes |
Family: | Viperidae |
Genus: | Crotalus |
Species: | C. cerastes |
Binomial name | |
Crotalus cerastes Hallowell, 1854 | |
Synonyms | |
Crotalus cerastes, known as the sidewinder, horned rattlesnake or sidewinder rattlesnake, [3] is a pit viper species belonging to the genus Crotalus (the rattlesnakes), and is found in the desert regions of the Southwestern United States and northwestern Mexico. Like all other pit vipers, it is venomous. Three subspecies are currently recognized. [4]
A small species, adult specimens measure between 43 and 76 cm (17 and 30 in) in length. [3] Most adults are 50–80 cm (19.5–31.5 in) in length. [5] The females are larger than the males, which is unusual for this group of snakes. [6]
Usually, 21 rows of keeled dorsal scales occur midbody. [3] [7] Males have 141 or fewer ventral scales; females have 144 or fewer. [3] It is sometimes referred to as the horned rattlesnake because of the raised supraocular scales above its eyes. This adaptation may help shade the eyes or prevent sand drifting over them as the snake lies almost buried in it. [6] As only pressure on top of the horns will cause them to fold down, it is concluded that they strike against the roof of rodent burrows to protect their eyes. [8]
The color pattern consists of a ground color that may be cream, buff, yellowish-brown, pink, or ash gray, overlaid with 28–47 dorsal blotches subrhombic or subelliptical in shape. [5] In the nominate subspecies, the belly is white and the proximal lobe of the rattle is brown in adults. Klauber and Neill describe the ability of this species to display different coloration depending on the temperature—a process known as metachrosis. [3]
Common names include sidewinder, horned rattlesnake, sidewinder rattlesnake, Mojave Desert sidewinder (for C. c. cerastes), [3] and sidewinder rattler. [9]
Images | Subspecies [4] | Taxon author [4] | Common name [10] | Geographic range [3] |
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C. c. cerastes | Hallowell, 1854 | Mojave Desert sidewinder | In the United States in the desert areas from northeastern Los Angeles County and San Bernardino County, California, northward to southern Mono County, California, east across Nevada to Washington County, Utah, and south through La Paz County, Arizona, in desert lowlands at elevations between 152 and 1,829 m | |
C. c. cercobombus | Savage & Cliff, 1953 | Sonoran Desert sidewinder | In the United States from Yuma, Maricopa, Pima, and Pinal Counties in Arizona, southward into Sonora, Mexico | |
C. c. laterorepens | Klauber, 1944 | Colorado Desert sidewinder | The desert areas in the United States from central and eastern Riverside County, California, to Pinal County, Arizona, south to northwestern Sonora in Mexico, and northwest to northeastern Baja California, from the Colorado River to the desert foothills at elevations between 152 and 610 m | |
In the Southwestern United States, this species is found in the desert region of southeastern California, southern Nevada, southwestern Utah, and western Arizona. In northwestern Mexico, it is found in western Sonora and eastern Baja California.
This species is classified as least concern on the IUCN Red List (v3.1, 2001). [1] 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. [11]
The common name sidewinder alludes to its unusual form of locomotion, which is thought to give it traction on windblown desert sand, but this peculiar locomotor specialization is used on any substrate over which the sidewinder can move rapidly. As its body progresses over loose sand, it forms a letter J-shaped impression, with the tip of the hook pointing in the direction of travel. Sidewinding is also the primary mode of locomotion in other desert sand dwellers, such as the horned adder ( Bitis caudalis ) and Peringuey's adder ( Bitis peringueyi ), but many other snakes can assume this form of locomotion when on slick substrates (e.g., mud flats). Sidewinder rattlesnakes can use sidewinding to ascend sandy slopes by increasing the portion of the body in contact with the sand to match the reduced yielding force of the inclined sand, allowing them to ascend up to the maximum possible sand slope without slip. [12] In cybernetics, incorporating this control scheme into a snakebot can enable the robot to replicate sidewinding movement. [12] Activity range does not change with sex or body size. [13]
The species is nocturnal during hot months and diurnal during the cooler months of its activity period, which is roughly from November to March (probably longer in the southern part of its range).
Juveniles use their tails to attract lizard prey, a behavior termed "caudal luring". Adults lose this behavior as they make the transition from lizard prey to their primary diet of desert rodents, birds, and other snakes. [14] Sidewinder juveniles appear to mimic both life stages of lepidopterans in their luring motions. Their fast luring motions resemble the fluttering of a moth, and their slower tail movements resemble a caterpillar. Both movements have been observed to attract prey lizards. [15]
Neonatal sidewinders engage in a remarkable behavioral homeothermy that has not been observed in any other type of snake. [16] Following birth, the neonates mass together in their natal burrow. Most often, gravid females select an east-facing, small-diameter rodent burrow for giving birth. For the first week or so of their lives, neonatal sidewinders plug the entrance to this burrow during daylight hours, forming a dynamic multiple-individual mass that takes advantage of the hot exterior environment and the cool interior of the burrow to maintain an average aggregate temperature of 32 °C (the optimal temperature for shedding). The dynamic mass of neonates modifies the thermal environment at the burrow entrance such that the young can occupy a location that would ordinarily become lethally hot for an individual neonate (or even an adult). [16] Because of the constant movements of the neonates, the aggregate assumes stable temperature properties reminiscent of a homeothermic organism (i.e., maintains tight temperature tolerance ± 2 °C).
Females produce up to 18 young, with an average of about 10 per litter. Like most other viperids, the young are born enveloped in thin embryonic membranes, from which they emerge shortly after being expelled from the mother. The young stay with their mother in a burrow for 7–10 days, shed for the first time, then leave their natal burrow. During this time, the mother is thought to guard and protect them from predators.
Sidewinders mature at 2–3 years of age, are capable of reproducing annually, and give birth to live young. Some females skip reproductive opportunities. [17] Some might even skip two years if the food supply is scarce. Sidewinders mate in April through May and sometimes in fall. When the male and female mate, the male snake crawls along the female's back, rubbing her with his chin to stimulate or arouse her. The male then will wrap his tail around her tail, and then will try to bring their cloacae together. The cloaca is the posterior body opening through which snakes both excrete waste and reproduce. If the female wants to mate, she lifts her tail and allows him to mate with her. The snakes can mate for several hours, and if one of the snakes decides to move, the other is dragged along. Females might mate with several males in a season. Females give birth to five to 18 young in late summer to early fall. The young are born 6-8 inches long. The birth takes only 2–3 hours altogether. Within a few minutes of being born, the newborn sidewinder escapes from a thin, transparent membrane. The young stay at their natal burrow for 7–10 days until they shed, [16] and then they disappear and have no future contact with their mother or their littermates. While the density of sidewinders can be up to one individual per hectare, they rarely encounter each other except during mating season. [17]
Sidewinders have an extraordinarily accelerated lifecycle, with natural life expectancies of females of about 5 years. [17] Males may live quite a bit longer (maximum known natural lifespan of 13 years). Sidewinders can live more than 20 years when well fed in captivity (even females). Thus, energetics apparently factor heavily into natural female mortality, [17] whereas predation might be the primary pressure on males. In the wild, females often die of exhaustion after giving birth, but the lives of sidewinders are also cut short by predation, diseases, and vehicle encounters.
These snakes are venomous, but possess a weaker venom than many other rattlesnakes. This, together with the smaller size of their venom glands, makes them less dangerous than their larger relatives. Regardless, any rattlesnake bite can be fatal and should be taken seriously and medical attention sought immediately.
Norris (2004) lists these venom yields: 33 mg average and 63 mg maximum (Klauber, 1956), and 30 mg average and 80 mg maximum (Glenn & Straight, 1982). [18] Brown (1973) gives a venom yield of 33 mg (Klauber, 1956) and LD50 values for mice of 2.6 mg/kg IV, 3.0, 4.0, 2.3 mg/kg IP and 5.5 mg/kg SC for toxicity. With these figures, Brown calculated that the LD50 for an adult human being weighing 70 kg would be 385 mg (SC). [19]
Envenomation can cause pain, swelling, hemorrhagic bleb formation, and ecchymosis (i.e., bruising). Swelling, while not particularly severe, occasionally may involve entire limbs and the trunk. Envenomation's systemic symptoms include nausea, dizziness, chills, coagulopathy (blood disorders), and shock. [18] Klauber (1997) includes an account of a man who had been bitten on the first joint of the index finger of the right hand, with only a single fang penetrating. Although the bite was described as no more painful than a pin prick, a doctor was seen within about 25 minutes, and 10 cm3 of antivenin were administered. Within 2.5 hours, his entire arm was swollen and the pain was severe, "as if the arm were soaked in a bucket of boiling oil." [10]
Ovine-derived antivenom, CroFab, for North American pit viper envenomation, has been widely available since 2001. Consultation with a local expert or regional poison control center should be obtained before administering antivenom. The previous antivenin (ACP) is no longer manufactured.
The Sidewinder Was the inspiration for the AIM-9 Sidewinder.
Rattlesnakes are venomous snakes that form the genera Crotalus and Sistrurus of the subfamily Crotalinae. All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting small animals such as birds and rodents.
Crotalus is a genus of pit vipers, commonly known as rattlesnakes or rattlers, in the family Viperidae. The genus is found only in the Americas from southern Canada to northern Argentina. The generic name Crotalus is derived from the Greek word κρόταλονkrótalοn, which means "rattle" or "castanet", and refers to the rattle on the end of the tail, which makes this group so distinctive. As of July 2023, 44 to 53 species are recognized as valid.
Sidewinding is a type of locomotion unique to snakes, used to move across loose or slippery substrates. It is most often used by the Saharan horned viper, Cerastes cerastes, the Mojave sidewinder rattlesnake, Crotalus cerastes, and the Namib desert sidewinding adder, Bitis peringueyi, to move across loose desert sands, and also by Homalopsine snakes in Southeast Asia to move across tidal mud flats. Any number of caenophidian snakes can be induced to sidewind on smooth surfaces, though the difficulty in getting them to do so and their proficiency at it vary greatly.
Cerastes cerastes, commonly known as the Saharan horned viper or the desert horned viper, is a venomous species of viper native to the deserts of Northern Africa and parts of the Arabian Peninsula and Levant. It is often easily recognized by the presence of a pair of supraocular "horns", although hornless individuals do occur. Three subspecies have been described.
Keeled scales refer to reptile scales that, rather than being smooth, have a ridge down the center that may or may not extend to the tip of the scale, making them rough to the touch. According to Street's (1979) description of European lizards and snakes, in those that have keeled scales the keels are usually stronger in male specimens and are consistently arranged according to the species of reptiles, even though many others do not have them. With European lizards, the dorsal scales are usually well keeled, while those on the flanks are more weakly keeled and those on the belly smooth. Non-European lizards such as Sphaerodactylus macrolepis also display keeled scales.
Crotalus scutulatus is known commonly as the Mohave Rattlesnake. Other common English names include Mojave Rattlesnake and, referring specifically to the nominate (northern) subspecies: Northern Mohave Rattlesnake and Mojave Green Rattlesnake, the latter name commonly shortened to the more colloquial “Mojave green”. Campbell and Lamar (2004) supported the English name “Mohave (Mojave) rattlesnake” with some reluctance because so little of the snake’s range lies within the Mojave Desert.
The eastern diamondback rattlesnake is a species of pit viper in the family Viperidae. The species is endemic to the Southeastern United States. It is one of the heaviest venomous snakes in the Americas and the largest rattlesnake. No subspecies are recognized.
The black-tailed rattlesnake is a venomous pit viper species found in the southwestern United States and Mexico. Four subspecies are currently recognized, including the nominate subspecies described here.
Cerastes is a genus of small, venomous vipers found in the deserts and semi-deserts of northern North Africa eastward through Arabia and Iran. Three species are currently recognized by ITIS, and an additional recently described species is recognized by the Reptile Database. Common names for members the genus include horned vipers, North African desert vipers, and cerastes vipers.
Crotalus basiliscus, known as the Mexican west coast rattlesnake, Mexican green rattler, and also by other names, is a species of pit viper in the family Viperidae. The species is endemic to western Mexico. Like all other pit vipers, it is venomous. The specific name, basiliscus, is derived from the Greek word for king, βασιλισκος, and alludes to this snake's large size and potent venom. No subspecies are currently recognized.
Crotalus helleri or Crotalus oreganus helleri, also known commonly as the Southern Pacific rattlesnake, the black diamond rattlesnake, and by several other common names, is a pit viper species or subspecies found in southwestern California and south into Baja California, Mexico, that is known for its regional variety of dangerous venom types. It is sometimes considered a subspecies of Crotalus oreganus.
Crotalus ruber is a venomous pit viper species found in southwestern California in the United States and Baja California in Mexico. Three subspecies are currently recognized, including the nominate subspecies described here.
The western diamondback rattlesnake or Texas diamond-back is a rattlesnake species and member of the viper family, found in the southwestern United States and Mexico. Like all other rattlesnakes and all other vipers, it is venomous. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the greatest number of snakebites in the U.S. No subspecies are currently recognized.
Crotalus enyo, commonly known as the Baja California rattlesnake or Lower California rattlesnake, is a pit viper species native to the coast and islands of northwestern Mexico. Like all other pit vipers, it is venomous. Three subspecies are currently recognized, including the nominate subspecies described here.
Crotalus durissus, known as the South American rattlesnake, tropical rattlesnake, and by other names, is a highly venomous pit viper species found in South America. It is the most widely distributed member of its genus. Currently, seven subspecies are recognized.
Crotalus oreganus, commonly known as the Western rattlesnake or northern Pacific rattlesnake, is a venomous pit viper species found in western North America from the Baja California Peninsula to the southern interior of British Columbia.
The tiger rattlesnake is a highly venomous pit viper species found in the southwestern United States and northwestern Mexico. No subspecies are currently recognized. The specific name tigris,, refers to the many narrow dorsal crossbands, which create a pattern of vertical stripes when viewed from the side.
The Persian horned viper, known as the Persian horned viper, false horned viper, and by other common names, is a species of vipers endemic to the Middle East and Asia. Like all other vipers, it is venomous.
Crotalus cerastes cercobombus, commonly known as the Sonoran Desert sidewinder or Sonoran sidewinder, is a pitviper subspecies found in the eastern part of the Sonoran Desert in the southwestern United States and northwestern Mexico. Like all pitvipers, it is venomous. The subspecific epithet means buzzertail.
Crotalus concolor, commonly known as the midget faded rattlesnake, faded rattlesnake, and yellow rattlesnake, is a pit viper species found in the western United States. It is a small rattlesnake known for its faded color pattern. Like all other pit vipers, it is venomous.