Crotalus cerastes cerastes - Mohave Desert Sidewinder

Venomous

The venom of this snake is potentially dangerous to humans.

Size

Adults are 17 - 33 inches. (43 - 84 cm). Snakes encountered will generally be 12 - 18 inches. Juveniles are about 7 inches at birth.

Appearance

A heavy-bodied, venomous pit viper, with a thin neck and a large triangular head. Pupils are elliptical. Scales are keeled. A dark eye stripe and a pointed and upturened horn-like scale above each eye. These horns may fold down over the eyes to protect them when the snakes is crawling in burrows.

Pale cream, tan, brown, pink, or grayish back color usually closely matches the soil surface allowing the snake to blend in with the background. Around 40 darker blotches on the back.

A thick tail with a rattle, consisting of loose interlocking segments, at the end. A new rattle segment is added each time the skin is shed. Newborn snakes do not have a rattle - just a single button which does not make a sound. The segment of the rattle closest to the body on an adult snake is brown. The Colorado Desert Sidewinder has a black segment. Heat sensing pits on the sides of the head help the snake to locate prey by their warmth.

Long, hollow, movable fangs connected to venom glands inject a toxic venom which quickly immobilize the prey. The snake can control the amount of venom injected and the fangs are replaced if broken. Though the amount of venom a sidewinder injects is relatively small and rarely deadly, bites on humans are potentially dangerous. Even a dead snake can bite and inject venom if the jaws open reflexively when they are touched.

Behavior

Primarily nocturnal and crepuscular during periods of excessive daytime heat, but also active during daylight when the temperature is more moderate. Not active during cooler periods in Winter.

An ambush hunter, it sits buried beneath the surface of loose sand with just the top of the head showing, near kangaroo rat warrens, and lizard or rodent trails, then strikes at and releases the prey. The snake then follows the trail of the envenomated animal and swallows it whole.

When alarmed, a rattlesnake shakes its tail back and forth. The movement rubs the rattle segments together producing a buzzing sound which serves as a warning. Juveniles are born with only a silent button at the end of the tail.

Moves with a sidewinding locomotion, throwing raised loops of the body to the side to push itself forward in an s-sheped curve. A sidewinders trail looks like a series of parallel j-shaped lines pointing roughly 45 degrees from the direction of movement.

Diet

Eats mainly lizards when young, and increasingly larger prey including small rodents when grown.

Reproduction

Live-bearing. Babies are produced late summer to mid-autumn.

Range

This subspecies, Crotalus cerastes cerastes - Mohave Desert Sidewinder, is found in south-central California south and east of the Sierras south to roughly the San Bernardino county line.

The species Crotalus cerastes - Sidewinder, is found in the Southern California deserts, east through southern Nevada to extreme southwestern Utah, into western Arizona, and south into northeast Baja California Mexico, and northwest Sonora, Mexico.

Habitat

Inhabits primarily areas of wind-blown sands, especially where sand hummocks are topped with vegetation. Also found in hardpan, open flats, rocky hillsides, and other desert areas, especially those grown with creosote bush, where the terrain is open, not obstructed by rocks or vegetation, allowing the broad sidewinding locomotion.