Arizona has some amazing, large lizards. This brightly colored one is an Eastern Collared Lizard. Based on a number of factors, they may be any variation of bright greens, blues, yellows, and oranges. This one was seen at a Prairie Rattlesnake den, carefully considering if we were something it needed to run away from.
A Banded Rock Rattlesnake from southeastern Arizona. These snakes are typically quick to rattle and flee into cover. But due to their small size, it can sound more like an insect than a rattlesnake. Despite being common and locally abundant, there is little chance of an accidental bite to anyone not purposely trying to capture one.
A thunderstorm materialized while I was hiking in a canyon in southern Arizona, so I ducked into a grove of suitable trees to wait it out and not be the tallest thing in the area. While waiting, I saw scales … though not many. It was a Banded Rock Rattlesnake that had emerged from nearby rocks to take advantage of the first rain in several months. It was a reminder that even when intently looking for them, most rattlesnake encounters are ones we will never know about.
An Arizona Ridgenosed Rattlesnake in southeastern Arizona. These small rattlesnakes are found in bunchgrass and oak leaf litter at elevations above around 4,500′. Though they may be locally abundant, most of the long-term locals asked in the area about them have no idea it exists.
Buontempo, M. J. (2024). Evolutionary history of a specialized and diverse highland snake complex (Crotalus willardi) (Doctoral dissertation, University of Texas at El Paso). https://scholarworks.utep.edu/cgi/viewcontent.cgi?article=5226&context=open_etd
A young Blacktailed Rattlesnake from the southeastern mountains of Arizona. When they are this age, they’ll often have subtle grey and black banding in the tail. This usually darkens to a solid black with age, but not always. Of the species of rattlesnakes in the state, coming across babies of this species out and about may be the least frequent for me.
A young Arizona Black Rattlesnake resting outside its den, where several larger adults have yet to emerge for the day. In time, it will darken and its pattern will fade to be the familiar dark black with yellow bands common in the region.
This same little snake, a year prior and a lot smaller, was what first gave this spot away as a rattlesnake den. Females stay at or near winter dens all year to give birth there, so a chance sighting of a neonate in August was an indication there was more to be found. Since then, I have found dozens more Arizona Black Rattlesnakes, as well as Western Diamondback Rattlesnakes and Blacktailed Rattlesnakes sharing the same den.
A Gila Monster out and about on a warm Spring day that I found a while back.
At that time, more than a decade ago, I knew relatively little about the day-to-day habits of these animals. Finding one was more a matter of luck than anything else. But, I’ve since learned a lot, and these are now often a higher observation count in a day than I’d had seen in an entire year.
Recommended reading, if you can find it:
Biology of Gila Monsters and Beaded Lizards — Daniel D. Beck (UC Press)
A large male Western Diamondback Rattlesnake cruising through dense vegetation, on the lookout for others that may be near. At this higher elevation den in the late fall, the females are already tucked into rock crevices and caves. All that remain on the surface are the largest males, patrolling for rivals, and getting into the occasional fight. This one finished its loop and settled back into the sunny spot it prefers for awhile, before doing it all again about an hour later. Why wait until spring to fight for the good spot, when you can do it in the fall?
Despite being incredibly easy to observe in surrounding mountain ranges, the Southwestern Speckled Rattlesnakes in the Sierra Estrella just southwest of Phoenix are harder to spot. They’re likely just as common, but the steep terrain and majority of prime geology for the species being inaccessible reservation land make it a challenge to see one. Kris Haas spotted this pretty one way up mountain.
A Mojave Rattlesnake from the grasslands of southeastern Arizona. This species in the area can be highly variable in appearance, from muted green tones to deeply contrasting browns and blacks, each can look very different from the next. This one is a more classic look, with dark diamonds against an olive green base color.
sThe stripe behind the eye, too, is classic Mojave Rattlesnake, extending straight back and never intersecting with the mouth. The two-tone tongue is also perfectly normal, though not always so pronounced.
