‹ Compare two snakes
Arizona Black Rattlesnake vs Western Diamondback Rattlesnake
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(c) tzeducation, some rights reserved (CC BY)
Arizona Black Rattlesnake
Crotalus cerberus
Venomous(c) Mike Lewinski, some rights reserved (CC BY)
Western Diamondback Rattlesnake
Crotalus atrox
VenomousThe quick way to tell
Look at the tail just before the rattle. The Arizona Black Rattlesnake has dark bands there that fade with age, often leaving the tail dark. The Western Diamondback has bold black-and-white 'coon-tail' rings.
Tail ★ This settles it
Ends in a rattle. The body blotches turn into dark bands on the tail, and these bands fade as the snake gets older.
Bold black and white rings, usually about equal width - the classic coon tail - ahead of the rattle.
Head
A wide, triangular rattlesnake head. Young snakes have bold spots on the head and a dark bar running back from the eye; these fade as the snake darkens with age.
Triangular head with a pale cheek stripe angling down to the mouth.
Pattern
25 to 46 dark blotches down the back, separated by lighter gaps. On dark adults the blotches can almost disappear into the dark background.
Fuzzy-edged, speckled-looking diamonds on dusty gray-brown.
Eyes
Vertical, cat-like pupils, as in other rattlesnakes. A dark bar runs back from each eye, most easily seen on young snakes.
Vertical slit pupil; heat-sensing pit between eye and nostril.
Pits
Yes. It has a heat-sensing pit on each side of the head between the eye and the nostril, like all rattlesnakes.
A deep heat-sensing pit on each side of the face, between the eye and the nostril.
What it does
Often calm compared with other rattlesnakes. It is social: groups share winter dens, bask together in spring, and mothers stay with their newborn young for about one to two weeks.
Rears into an S-coil and rattles loudly; stands its ground more than most.
Where it lives
Central Arizona, from the Mogollon Rim south to mountain ranges near Tucson, and west-central New Mexico. Mostly found at about 2,800–9,150 ft (853–2,789 m).
Southwest and southern plains: southeastern California, southern Nevada, Arizona, New Mexico, Texas, Oklahoma and edges of Kansas and Arkansas, south into central Mexico.