Crotalus scutulatus scutulatus - Northern Mohave Rattlesnake

Venomous

The venom of this snake is potentially dangerous to humans.

Size

Adults 24 - 51 inches long (61 - 129 cm) Most snakes encountered are from 18 - 40 inches in length. Newborns are about 10.5 inches.

Appearance

A heavy-bodied, dangeously venomous pit viper, with a thin neck and a large triangular head. Pupils are elliptical. Scales are keeled. Usually there are 2 or 3 large scales on the top of the head between the supraoculars. (The Western Diamond-backed Rattlesnake usually has 4 or more small scales between the supraoculars.) A light stripe runs from behind the eye diagonally to the upper lip beyond the corner of the mouth, but does not cross over the lip. (The posterior light stripe of the Western Diamond-backed Rattlesnake extends to the upper lip in front of the corner of the mouth, crossing over the lip.)

Ground color varies from greenish gray, yellow, tan, olive green, to brown. Irregular, dark, well-defined, diamond or near diamond-shaped dorsal markings.

Black and white rings surround a thick tail. The black rings are narrower than the light rings, and often offset. A rattle on the end of the tail, consisting of loose interlocking segments. 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.

Similar to and easily confused with the Western Diamond-backed Rattlesnake, though there is little range overlap in California.

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 very toxic venom which quickly immobilize prey. The snake can control the amount of venom injected and the fangs are replaced if broken. Bites on humans are potentially dangerous without immediate medical treatment. Even a dead snake can bite and inject venom if the jaws reflexively open 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.

Prey is found while the snake is actively moving, or by ambush, where the snake waits near lizard or rodent trails, striking at and releasing passing 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.

Diet

Eats small mammals, including ground squirrels, mice, rats, rabbits and hares, and occasionally lizards, snakes, and toads.

(Adult California Ground Squirrels are immune to rattlesnake venom and will intensely confront any snake they feel to be a threat.)

Reproduction

Live-bearing; young are born July - September. Male to male combat occurs. You can see two snakes wrestling on this UTube movie.

Range

Found in southeastern California from the Colorado river roughly near the San Bernardino County line, west through the Mojave desert, north, east of the Sierras into Inyo County. Absent from the southeastern Colorado deserts, but there are unconfirmed reports of sightings west of the Colorado River in Imperial County. Ranges north into Nevada, east into west Texas, and far south into Mexico.

Habitat

Inhabits grassland, desert scrub, rocky slopes, creosote bush flats, open juniper woodland, and light chaparral.