Western Diamondback Rattlesnake
Crotalus atrox • Order: Squamata, Suborder: Serpentes, Family: Viperidae, Subfamily: Crotalinae, Genus: Crotalus, Species: atrox
Southwestern United States (Arkansas, Texas, Oklahoma, New Mexico, Arizona, California, Nevada) and Northern to Central Mexico.
Look up Western Diamondback Rattlesnake in the Snake Encyclopedia →Venomous Status
Venomous; solenoglyphous (large, retractable front fangs).
Danger Level
Extremely Dangerous; responsible for the majority of snakebite fatalities in northern Mexico and the second greatest number in the USA.
Family
Order: Squamata, Suborder: Serpentes, Family: Viperidae, Subfamily: Crotalinae, Genus: Crotalus, Species: atrox
Conservation
Least Concern (IUCN); however, threatened locally by rattlesnake roundups and habitat loss.
Physical Description
Large heavy body with triangular head; heat-sensing pits between eye and nostril; dusty gray-brown coloration with dark diamond-shaped dorsal blotches outlined in white. Distinctive 'coon tail' of black and white rings before the rattle.
Size & Dimensions
Specimen appears to be an adult. Adults typically range from 120 to 150 cm (4 to 5 feet), with a maximum recorded length of 213 cm (7 feet).
Habitat
Arid and semi-arid regions including deserts, grasslands, pine-oak woodlands, and rocky canyons. Found from sea level up to 2,400 meters elevation.
Behavior & Temperament
Defensive and easily agitated. When threatened, creates a S-coil and shakes its rattle. Predominantly nocturnal in summer and diurnal in spring/fall.
Diet & Feeding
Generalist carnivore feeding on small mammals (rabbits, mice, rats), birds, and lizards. Ambush predator using heat pits to locate prey at night.
Reproduction
Ovoviviparous; females give birth to 6-25 live young between July and October. Young are born fully functional with venom and a single 'button'.
Venom Profile
Primarily hemotoxic and cytotoxic, causing extensive tissue damage, necrosis, and coagulopathy; also contains some myotoxic components.
Look-alikes
Crotalus scutulatus (Mohave Rattlesnake) - distinguished by larger scales on head and wider white bands on tail; Crotalus adamanteus - found in the Eastern US.
Conservation Status
Least Concern (IUCN); however, threatened locally by rattlesnake roundups and habitat loss.
Cultural Significance
Iconic symbol of the American Southwest; features heavily in Native American folklore and modern Western culture as a symbol of wildness and danger.
Notable Features
Features a multi-segmented keratin rattle used as an auditory warning. Possesses highly evolved loreal pits for infrared thermoreception, allowing for hunting in total darkness.