Crotalus triseriatus
Silhouette: Bill Bouton (source photo) & T. Michael Keesey (vectorization) · PhyloPic
In 3 days ~60% in a week ~90%
Common names: Mexican dusky rattlesnake, dusky rattlesnake Crotalus triseriatus is a venomous pit viper species found in Mexico. Two subspecies are currently recognized, including the nominate subspecies described here. Adult male specimens of C. triseriatus commonly grow to a total length (including tail) greater than 60 cm (24 in), with females somewhat smaller. The maximum recorded total length is 68.3 cm (26.9 in).
The species C. triseriatus is found in Mexico, along the southern edge of the Mexican Plateau in the highlands of the Transverse Volcanic Cordillera, including the states of Jalisco, México, Michoacán, Morelos, Nayarit, Puebla, Tlaxcala, and Veracruz. The type locality given by Wagler in 1830 is "Mexico". A restriction to "Alvarez, San Luis Potosí, Mexico" was proposed by H.M. Smith and Taylor (1950).
Crotalus triseriatus occurs in pine-oak forest, boreal forest, coniferous forest and, bunchgrass grasslands. On Volcán Orizaba, it is found at very high altitudes. There, the snow line comes down to about 4,572 m (15,000 ft), while green plants can be found up to 4,573 m (15,000 ft): the species has been found within... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Reserva de la Biosfera Mariposa Monarca | 🇲🇽 Mexico |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Toluca | 🇲🇽 México | |
| 2 | Mexico City | 🇲🇽 México |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | North Carolina Zoo | 🇺🇸 United States | |
| 2 | Saint Louis Zoo | 🇺🇸 United States | |
| 3 | San Antonio Zoo | 🇺🇸 United States |
No species of the same family or order lives in Reserva de la Biosfera Mariposa Monarca, so these are its closest relatives here: other reptiles.
Possible
About 30% of wildlife watchers report a Dusky Rattlesnake sighting in Reserva de la Biosfera Mariposa Monarca on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 5th most-seen of the 6 reptiles we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
April
In that month about 60% of wildlife watchers report a Dusky Rattlesnake in Reserva de la Biosfera Mariposa Monarca on a given day, against under 5% in May, August and December, the lowest months. That is one of Reserva de la Biosfera Mariposa Monarca's driest months, with about 40 mm of rain against 270 mm in July.
Between 6 and 9 pm
Across all the parks we cover, that three-hour window holds the most Dusky Rattlesnake sightings with a recorded time, and about 9 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Only Reserva de la Biosfera Mariposa Monarca, in our data
Reserva de la Biosfera Mariposa Monarca is the only park on Wallace's Line with enough records to rate Dusky Rattlesnake sightings: about 30% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Dusky Rattlesnake is recorded against all the reptiles logged in Reserva de la Biosfera Mariposa Monarca (5 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.
