Crotalus ruber
Silhouette: Bill Bouton (source photo) & T. Michael Keesey (vectorization) · PhyloPic
In 3 days ~40% in a week ~70%
Common names: red diamond rattlesnake, red rattlesnake, red diamond snake, more Crotalus ruber is a venomous pit viper species found in southwestern California in the United States and Baja California in Mexico. Three subspecies are currently recognized, including the nominate subspecies described here.
Common names include: red diamond rattlesnake, red rattlesnake, red diamond snake, red diamond-backed rattlesnake, red rattler, and western diamond rattlesnake. The form found on Cedros Island, previously described as C. exsul, was referred to as the Cedros Island diamond rattlesnake, or Cedros Island rattlesnake.
Not enough genetic and morphological diversity exists between C. exsul from Cedros Island and C. ruber from the mainland to warrant the recognition of both species. In response, Smith et al. (1998) petitioned the ICZN to validate ruber over exsul in the interest of nomenclatural stability. Wikipedia →
Recording0:08
United States · 2020
© Jeremey Freely · iNaturalist · CC BY-NC 4.0
Recording0:24
Mexico · 2026
© Sean Daniels · iNaturalist · CC BY-NC 4.0
Recording0:07
United States · 2021
© casjessi · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | El Vizcaíno Biosphere Reserve | 🇲🇽 Mexico | |
| 2 | Cabo Pulmo National Park | 🇲🇽 Mexico | |
| 3 | Bahía de Loreto National Park | 🇲🇽 Mexico | |
| 4 | Joshua Tree National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San Diego | 🇺🇸 United States | |
| 2 | Los Angeles | 🇺🇸 United States |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | San Diego Zoo | 🇺🇸 United States | |
| 2 | Moscow Zoo | 🇷🇺 Russia | |
| 3 | Los Angeles Zoo | 🇺🇸 United States | |
| 4 | Zoológico "Parque del niño" Jersey | 🇲🇽 Mexico | |
| 5 | Burgers' Ocean | 🇳🇱 Netherlands | |
| 6 | Royal Burgers' Zoo | 🇳🇱 Netherlands | |
| 7 | Arizona-Sonora Desert Museum | 🇺🇸 United States | |
| 8 | Philadelphia Zoo | 🇺🇸 United States | |
| 9 | Riverbanks Zoo | 🇺🇸 United States | |
| 10 | California Living Museum | 🇺🇸 United States | |
| 11 | Reptile Gardens | 🇺🇸 United States | |
| 12 | Cherkasy Zoo | 🇺🇦 Ukraine | |
| 13 | Orange County Zoo | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Red Diamond Rattlesnake sighting in Bahía de Loreto National Park on a given day, based on 12 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 11th most-seen of the 20 reptiles we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
September
In that month about 50% of wildlife watchers report a Red Diamond Rattlesnake in Bahía de Loreto National Park on a given day, against under 5% in April, June, August and December–February, the lowest months. That is one of Bahía de Loreto National Park's wettest months, with about 80 mm of rain against almost none in April.
Between 7 and 10 pm
Across all the parks we cover, that three-hour window holds the most Red Diamond Rattlesnake sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is seen both by day and at night.
3rd of 4
Of the 4 parks where we can rate Red Diamond Rattlesnake sightings, Bahía de Loreto National Park ranks 3rd at about 10%. The best odds are in El Vizcaíno Biosphere Reserve (Mexico, about 30%) and Cabo Pulmo National Park (Mexico, about 20%).
GBIF citizen-science records
It is estimated from how often the Red Diamond Rattlesnake is recorded against all the reptiles logged in Bahía de Loreto National Park (12 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.
