Гремучая змея бокового перемещения: описание и особенности

Species of snake

Crotalus cerastes, known as the sidewinder, horned rattlesnake or sidewinder rattlesnake, 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.

A small species, adult specimens measure between in length. The females are larger than the males, which is unusual for this group of snakes. Usually, 21 rows of keeled dorsal scales occur midbody. Males have 141 or fewer ventral scales; females have 144 or fewer. 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.

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).

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. In cybernetics, incorporating this control scheme into a snakebot can enable the robot to replicate sidewinding movement. 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. 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. Neonatal sidewinders engage in a remarkable behavioral homeothermy that has not been observed in any other type of snake. 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). 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, Brown (1973) gives a venom yield of 33 mg (Klauber, 1956) and 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). 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. 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.

SubspeciesTaxon authorCommon nameGeographic rangeC. c. cerastesHallowell, 1854Mojave Desert sidewinderIn 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 mC. c. cercobombusSavage & Cliff, 1953Sonoran Desert sidewinderIn the United States from Yuma, Maricopa, Pima, and Pinal Counties in Arizona, southward into Sonora, MexicoC. c. laterorepensKlauber, 1944Colorado Desert sidewinderThe 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