Category: pricei

A New Rattlesnake for the National Park System: Twin-Spotted Rattlesnakes at Chiricahua National Park

Posted on by Bryan Hughes

A new rattlesnake for the National Park system. The newly minted Chiricahua National Park includes habitat for one of our state’s lesser-known venomous snakes.

Twin Spotted Rattlesnakes are small, high-elevation rattlesnakes that live in a handful of mountain ranges in the Sky Islands region of Arizona. Hikers may see them rarely, visiting the peaks and upper saddles of the Santa Rita, Huachuca, Pinaleno, and Chiricahua ranges.

In the Chiricahuca National Park, they may be found at the upper elevations, above 6,000′. Much of the park is lower than that, but the longer trails leading to Massai Point get into the right areas where one may be spotted.

They’re so small (usually under 2 feet long as adults) that most long-term visitors don’t even know they exist. They do rattle, but usually just silently slip off the trail or into the rocks. If a rattle does happen, it’s a quiet buzz that sounds more like an insect than a rattlesnake.

Twin-Spotted Rattlesnakes are protected in Arizona and should never be captured or killed.

Prival, D. B., Goode, M. J., Swann, D. E., Schwalbe, C. R., & Schroff, M. J. (2002). Natural history of a northern population of twin-spotted rattlesnakes, Crotalus pricei. Journal of Herpetology, 36(4), 598–607. https://doi.org/10.1670/0022-1511(2002)036[0598:NHOANP]2.0.CO;2

Twin Spotted Rattlesnake in an Example of Habitat

Posted on by Bryan Hughes

A Twin Spotted Rattlesnake in habitat at the top of a mountain in southern Arizona. These are rattlesnakes that are often mistaken as a non-venomous species due to their small size and head that is not as strongly differentiated from the neck as people expect. They are rarely seen by hikers, but a “what is this snake?” photo of one tends to pop up a few times a year from the Santa Rita mountains south of Tucson.

This is a young individual that I spotted as I climbed up to the ridgeline from a fruitless search below. It never made a sound, but slipped silently into the rocks to escape, as they do. I surely walked past a dozen more, who performed this disappearing act with better timing.

Twin-Spotted Rattlesnake in Arizona

Posted on by Bryan Hughes

Twin Spotted Rattlesnakes (Crotalus pricei) are small, high-elevation rattlesnakes that are found in a handful of mountain ranges in the Sky Islands region of Arizona and northern Mexico. They are occasionally seen by hikers on high saddles and trails, where they are quick to flee with a departing buzz. A person would really have to pick one up or be hiking barefoot to get bitten by one, if they’re even lucky enough to see one or have it stick around long enough for that to happen.

Twin Spotted Rattlesnake High on Mt. Graham

Posted on by Bryan Hughes

A Twin Spotted Rattlesnake that we found in eastern Arizona, showing off many more than “twin” spots. These tiny rattlesnakes can vary greatly in appearance from one location to the next, even between individuals in a single population. These are not likely to be seen unless you are spending time in the highest areas of a handful of the Chiricahua, Huachuca, Pinaleño, or Santa Rita mountain ranges.

Prival, D. B., Goode, M. J., Swann, D. E., Schwalbe, C. R. (2002), & Schroff, M. J.. Natural History of a Northern Population of Twin-Spotted Rattlesnakes, Crotalus pricei. Journal of Herpetology, 36(4), 598–607.

DOI: https://doi.org/10.1670/0022-1511(2002)036[0598:NHOANP]2.0.CO;2

Twin-Spotted Rattlesnake

Posted on by Bryan Hughes

A Twin-Spotted Rattlesnake with a relatively drab pattern, but not atypical for an older adult. These are small snakes, rarely seen by hikers, as their range within the U.S. consists of only a handful of mountains in southeastern Arizona. In addition to rodents, these rattlesnakes also specialize in lizards, often taking the colorful Yarrows Spiny Lizards also common to rocky outcrops in high pine forests. These are among the protected species within Arizona, but a good number of them still end up being taken from the mountains each year to enter the European black market.

Prival, D. B., Goode, M. J., Swann, D. E., & Schwalbe, C. R. (2002). Natural history of a northern population of twin-spotted rattlesnakes, Crotalus pricei. Journal of Herpetology, 36(4), 598–607. https://doi.org/10.1670/0022-1511(2002)036[0598:NHOANP]2.0.CO;2

Prival, D. B., & Schroff, M. J. (2012). A 13-year study of a northern population of twin-spotted rattlesnakes (Crotalus pricei): Growth, reproduction, survival, and conservation. Herpetological Monographs, 26(1), 1–18. https://doi.org/10.1655/HERPMONOGRAPHS-D-11-00002.1

Prival, D. B., Goode, M. J., Swann, D. E., & Schwalbe, C. R. (1999). A comparative study of hunted vs. unhunted populations of the twin-spotted rattlesnake. Unpublished report, University of Arizona. PDF link

Grabowsky, E. R., & Mackessy, S. P. (2019). Predator-prey interactions and venom composition in a high elevation lizard specialist, Crotalus pricei (Twin-spotted Rattlesnake). Toxicon, 170, 88–97. https://doi.org/10.1016/j.toxicon.2019.09.003

Grabowsky, E. (2018). Venom composition of little known mountain rattlesnakes and predator-prey interactions of Crotalus pricei pricei and its natural prey, Sceloporus jarrovii (Master’s thesis). University of Northern Colorado. https://digscholarship.unco.edu/theses/251/

Bezy, R. L. (2021). Biogeographic outliers in the Arizona herpetofauna. Sonoran Herpetologist, 34(2), 45–58. PDF

Pough, F. H. (1966). Ecological relationships of rattlesnakes in southeastern Arizona with notes on other species. Copeia, 1966(4), 649–658. https://doi.org/10.2307/1441401

Bezy, R. L., & Cole, C. J. (2014). Amphibians and reptiles of the Madrean Archipelago of Arizona and New Mexico. American Museum Novitates, 2014(3810), 1–24. https://doi.org/10.1206/3810.1

Kauffeld, C. F. (1943). Field notes on some Arizona reptiles and amphibians. The American Midland Naturalist, 29(2), 342–359. https://doi.org/10.2307/2420795

Gloyd, H. K. (1937). A herpetological consideration of faunal areas in southern Arizona. Bulletin of the Chicago Academy of Sciences, 5(6), 79–136.

Twin-Spotted Rattlesnake In High Places

Posted on by Bryan Hughes

Rattlesnakes live in the highest areas of Arizona, often taking forms that defy what most residents would think possible. This one, an adult Twin-Spotted Rattlesnake (Crotalus pricei), is only about 20″ long as a mature adult, with a narrow head, tiny rattle, and body pattern that convergently looks just like a harmless nightsnake.

These are one of the four species of rattlesnakes in Arizona that are protected by law from any kind of disturbance, thankfully.

Twin-Spotted Rattlesnake In High Places