Crotalus cerastes
Silhouette: Bill Bouton (source photo) & T. Michael Keesey (vectorization) · PhyloPic
In 3 days ~20% in a week ~40%
Crotalus cerastes, also known commonly as the horned rattlesnake, the sidewinder, and the sidewinder rattlesnake, is a species of pit viper, a venomous snake in the subfamily Crotalinae of the family Viperidae. The species is native to desert regions of the Southwestern United States and adjacent northwestern Mexico. Three subspecies are recognized as being valid.
A small species, adult specimens of Crotalus cerastes measure between 43 and 80 cm (17 and 31.5 in) in total length (tail included). The females are larger than the males, which is unique among United States rattlesnakes.
Usually, 21 rows of keeled dorsal scales occur midbody. Males have 141 or fewer ventral scales; females have 144 or fewer. It is sometimes referred to as the horned rattlesnake because of the raised supraocular scales above its eyes. This adaptation may help shade the eyes or prevent sand drifting over them as the snake lies almost buried in it. As only pressure on top of the horns will cause them to fold down, it is concluded that they strike against the roof of rodent burrows to protect the eyes.
The color pattern consists of a ground color that may be cream, buff, yellowish-brown, pink... Wikipedia →
Recording0:17
United States · 2025
© James Bailey · iNaturalist · CC BY-NC 4.0
Recording0:02
United States · 2021
© BJ Stacey · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Death Valley National Park | 🇺🇸 United States | |
| 2 | Joshua Tree National Park | 🇺🇸 United States | |
| 3 | Saguaro National Park | 🇺🇸 United States |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Moscow Zoo | 🇷🇺 Russia | |
| 2 | North Carolina Zoo | 🇺🇸 United States | |
| 3 | Zoo Pilsen | 🇨🇿 Czechia | |
| 4 | Greensboro Science Center | 🇺🇸 United States | |
| 5 | Living Desert Zoo and Gardens | 🇺🇸 United States | |
| 6 | Columbus Zoo and Aquarium | 🇺🇸 United States | |
| 7 | Ecological Center of Sonora | 🇲🇽 Mexico | |
| 8 | Omaha’s Henry Doorly Zoo and Aquarium | 🇺🇸 United States | |
| 9 | Phoenix Zoo | 🇺🇸 United States | |
| 10 | Louisville Zoo | 🇺🇸 United States | |
| 11 | Oklahoma City Zoo and Botanical Garden | 🇺🇸 United States | |
| 12 | Terra Natura Benidorm | 🇪🇸 Spain | |
| 13 | Fort Worth Zoo | 🇺🇸 United States | |
| 14 | Indianapolis Zoo | 🇺🇸 United States | |
| 15 | Zoo Knoxville | 🇺🇸 United States | |
| 16 | Houston Zoo | 🇺🇸 United States | |
| 17 | Arizona-Sonora Desert Museum | 🇺🇸 United States | |
| 18 | Philadelphia Zoo | 🇺🇸 United States | |
| 19 | Zoo Atlanta | 🇺🇸 United States | |
| 20 | London Zoo | 🇬🇧 United Kingdom | |
| 21 | El Paso Zoo | 🇺🇸 United States | |
| 22 | Faunia | 🇪🇸 Spain | |
| 23 | Buffalo Zoo | 🇺🇸 United States | |
| 24 | Chattanooga Zoo at Warner Park | 🇺🇸 United States | |
| 25 | Orange County Zoo | 🇺🇸 United States | |
| 26 | Downtown Aquarium, Houston | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Sidewinder sighting in Saguaro National Park on a given day, based on 134 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 36th most-seen of the 51 reptiles we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
September
In that month about 20% of wildlife watchers report a Sidewinder in Saguaro National Park on a given day, against under 5% in November to March, the lowest months. That is one of Saguaro National Park's wettest months, with about 50 mm of rain against almost none in May.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Sidewinder sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
3rd of 3
Of the 3 parks where we can rate Sidewinder sightings, Saguaro National Park ranks 3rd at about 10%. The best odds are in Death Valley National Park (United States, about 40%) and Joshua Tree National Park (United States, about 20%).
Same genus: Crotalus
The closest relatives of the Sidewinder 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 Sidewinder is recorded against all the reptiles logged in Saguaro National Park (134 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.
