Viperidae, the Viper and Pit viper family.
IUCN Least Concern.
Extreme southwestern Utah, southern Nevada, California, south into Mexico.
Desert of wind blown sand, especially around sand hummocks topped with creosote bushes or mesquite.
Juvenile Sidewinders use their tails to attract lizard prey, a behavior termed “caudal luring”.
These are small, tan to gray rattlesnakes with dark blotches, typically narrow necks and triangular heads with pointed, horn-like scales above their eyes and small rattles. They move across the sand by “sidewinding”, looping their bodies forward diagonally toward their goal.
They are chiefly nocturnal, spending their days in rodent burrows or the shade of bushes. They coil themselves down into the loose sand so that their backs are flush with the surface and their lowermost coils in contact with the cooler sand below, perfectly camouflaged.
Their diet consists of small mammalsand lizards, which also supplies all their water needs. They locate prey by “sniffing” the air with tongue and Jacobson’s organ and by sensing for warm bodies with special heat-sensing pit organs and inject venom with fangs. Their prey is swallowed whole.
They are preyed on by kingsnakes, coyotes, roadrunners and raptors.
Breeding takes place in spring. Females give birth to as many as 18 live young, fully equipped with fangs and venom. The young are born encased in thin membranes out of which they emerge shortly after birth. They stay near their burrow for 7-10 days, then leave.