Western Black-tailed Rattlesnake
Crotalus molossus
Silhouette: Bill Bouton (source photo) & T. Michael Keesey (vectorization) · PhyloPic
- KingdomAnimalia (Animals)
- PhylumChordata (Chordates)
- ClassSquamata
- FamilyViperidae (Vipers)
- GenusCrotalus (Rattlesnakes)
- SpeciesCrotalus molossus (Western Black-tailed Rattlesnake)
About the Western Black-tailed Rattlesnake
The black-tailed rattlesnake (Crotalus molossus) is a venomous pit viper species found in the southwestern United States and Mexico. Four subspecies are currently recognized, including the nominate subspecies described here.
A 2012 revision showed that eastern populations from Texas and central and eastern New Mexico form a distinct species separate from C. molossus: Crotalus ornatus Hallowell 1854. Alternate common names are green rattler, and Northern black-tailed rattlesnake.
This medium-sized species averages from 76 to 107 cm (30 to 42 in) in length. Large specimens are usually not much more than 100 cm (39 in) long, although lengths of 125.0 cm (49.2 in) (Gloyd, 1940), 125.7 cm (49.5 in) (Klauber, 1972), and 129.5 cm (51.0 in) (Shaw & Campbell, 1974) have been reported. The females tend to be larger than the males.
They range in color from yellows and olive greens to browns and black. As their name implies, one of their most distinguishing features is, despite variations in body color, entirely black tail scales. Often, this rattlesnake has a black band across its eyes extending diagonally down to the corners of its mouth... Wikipedia →
Recent sightings of Western Black-tailed Rattlesnake in Reserva de la Biosfera Mariposa Monarca
LIVEiNaturalistClosest Relatives at Reserva de la Biosfera Mariposa Monarca
Global Distribution
Warmer areas are where this animal is recorded most often.
Parks Where Found
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States | |
| 2 | Reserva de la Biosfera Mariposa Monarca | 🇲🇽 Mexico |