Crotalus cerberus
Silhouette: Bill Bouton (source photo) & T. Michael Keesey (vectorization) · PhyloPic
In 3 days ~30% in a week ~60%
Crotalus cerberus is a venomous pit viper species found in the southwestern United States. It is known as the Arizona black rattlesnake, black rattlesnake, and several other common names. According to Wright and Wright (1957), adults grow to an average length of 78–109 cm (31–43 in). Klauber (1997) reports the maximum length to be less at 1,032 mm (40+5⁄8 in), with the smallest gravid female measuring 701 mm (27+5⁄8 in). Hubbs and O'Connor (2012) list an adult size range of 812–1,219 mm (32.0–48.0 in).
The ground color varies among dark grayish, brownish black, reddish brown, or blackish. This is overlaid with a dorsal pattern of blotches that are rectangular anteriorly, become subhexagonal posteriorly, and finally form crossbands just before the tail.
However, specimens also may be a uniform dark color without any clear dorsal pattern, or the dorsal blotches may be even darker and bordered with white, cream, or yellow transverse rows of scales, or the color pattern may be quite pale with a significant amount of yellow mixed in. A postocular stripe is evident in lightly colored specimens, but not so much in darker ones.
Arizona black rattlesnakes... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Cabarceno Natural Park | 🇪🇸 Spain | |
| 2 | Omaha’s Henry Doorly Zoo and Aquarium | 🇺🇸 United States | |
| 3 | Phoenix Zoo | 🇺🇸 United States | |
| 4 | Houston Zoo | 🇺🇸 United States | |
| 5 | Arizona-Sonora Desert Museum | 🇺🇸 United States | |
| 6 | Alligator Adventure | 🇺🇸 United States | |
| 7 | Ellen Trout Zoo | 🇺🇸 United States | |
| 8 | Reptile Gardens | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report an Arizona Black Rattlesnake sighting in Saguaro National Park on a given day, based on 46 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 22nd most-seen of the 51 reptiles we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
May and July–September
In those months about 20% of wildlife watchers report an Arizona Black Rattlesnake in Saguaro National Park on a given day, against under 5% in November to March, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Arizona Black Rattlesnake sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Saguaro National Park, in our data
Saguaro National Park is the only park on Wallace's Line with enough records to rate Arizona Black Rattlesnake sightings: about 10% of wildlife watchers there report one on a given day.
Same genus: Crotalus
The closest relatives of the Arizona Black Rattlesnake that you can see in Saguaro National Park (genus Crotalus, Rattlesnakes) are Western Diamondback Rattlesnake (about 40%), Western Black-tailed Rattlesnake (about 20%) and Tiger Rattlesnake (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Arizona Black Rattlesnake is recorded against all the reptiles logged in Saguaro National Park (46 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
