‹ Compare two snakes
Arizona Black Rattlesnake vs Black-tailed Rattlesnake
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Arizona Black Rattlesnake
Crotalus cerberus
Venomous(c) Zihao Wang, some rights reserved (CC BY)
Black-tailed Rattlesnake
Crotalus molossus
VenomousThe quick way to tell
Look at the body color. The Arizona Black Rattlesnake has a dark gray-brown to black body, and adults can look almost solid black with thin pale crossbars. The Black-tailed Rattlesnake has a paler yellow, greenish or gray body with large dark blotches, ending in an all-black tail.
Pattern ★ This settles it
25 to 46 dark blotches down the back, separated by lighter gaps. On dark adults the blotches can almost disappear into the dark background.
Dark diamond- or patch-shaped blotches with pale insides, becoming crossbands near the tail.
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.
Broad triangular head; the front of the snout is usually black or dark brown, often with a dark band between the eyes.
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.
Tail
Ends in a rattle. The body blotches turn into dark bands on the tail, and these bands fade as the snake gets older.
Solid black or dark gray ahead of the rattle, with few or no bands.
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.
Often calm and slow to rattle, though some rattle quickly; climbs well.
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).
Western and southern Arizona east through New Mexico to west and central Texas, south into Mexico.