Sceloporus clarkii Clark's Spiny Lizard
Some other names for this species:
Clark Spiny Lizard
Subspecies I've seen:
S. c. clarkii
Sonoran Spiny Lizard
S. c. vallaris
Plateau Spiny Lizard
Sceloporus clarkii clarkii Sonoran Spiny Lizard
On grounds of Arizona Sonoran Desert Museum, Tucson, Pima County, ArizonaApril 9, 1999
Sonoran Spiny Lizard (Sceloporus clarkii clarkii)
Most of the Arizona Sonoran Desert Museum grounds are outdoors, and a variety of native and non-native species live wild there. This young spiny lizard was clinging to a boulder along the main trail through the outdoor part of the museum.
Pima Canyon, Tucson, Pima County, ArizonaApril 11, 1999
Sonoran Spiny Lizard (Sceloporus clarkii clarkii)
This very large and very dark individual tried to hide behind the tree trunk it was perched upon by constantly shuffling to stay on the opposite side of me. Eventually it decided on the safety of some nearby boulders, and I got just a couple of poor photos as it scurried away.
San Pedro Riparian Conservation Area, Cochise County, ArizonaMay 14, 2000
Sonoran Spiny Lizard (Sceloporus clarkii clarkii)
These robust spiny lizards were fairly common in the trees lining the San Pedro river, though they're wary and difficult to approach. Youngsters and females are dark and camouflaged well on tree trunks. Some of the large males are very light with extremely pronounced black collars. We saw two pairs of large adults on different trees, and several individuals scattered about. Unfortunately all the large light-colored males raced up the tree trunks before I could get a decent picture. The sneaky-looking fellow in this picture gives you a hint of the dramatically different appearance of these large males.
City of Rocks State Park, Luna County, New MexicoMay 27, 2008
Sonoran Spiny Lizard (Sceloporus clarkii clarkii) Sonoran Spiny Lizard (Sceloporus clarkii clarkii)
This big male spiny lizard occupied a rock a few feet away from a big female spiny lizard. She was enough shyer that I didn't end up with any photos, but he was a lot prettier anyway.
Santa Cruz County, ArizonaAugust 18, 2013
Sonoran Spiny Lizard (Sceloporus clarkii clarkii) Sonoran Spiny Lizard (Sceloporus clarkii clarkii)
While whiling away the oh-so-hot midday hours in anticipation of some exciting nocturnal herping, I chased around a bunch of S. clarkii before I could get one or two of them to stay in place for a few moments.
Alamo Canyon, Organ Pipe National Monument, Pima County, ArizonaAugust 3, 2014
Sonoran Spiny Lizard (Sceloporus clarkii clarkii)
I hiked Alamo Canyon this morning specifically to look for Sonoran Collared Lizards. The first lizards I saw were a bunch of Zebra-tailed Lizards, which are much smaller and thinner than collared lizards, and which are typically on the desert floor whereas collared lizards are typically up on boulders. Then in the distance I saw a large, thick lizard up on a boulder, and whipped out my binoculars. Collared lizard? Hmm? But no! It was just a Sonoran Spiny Lizard, an easily-found species that I had seen many times before. Still, a reasonably cool lizard.

But do not fret for me. I did eventually find my quarry that morning. (Oh, you weren't fretting for me? Well, you should have been.)

Sceloporus clarkii vallaris Plateau Spiny Lizard
Sedona, Coconino County, ArizonaAugust 14, 2004
Plateau Spiny Lizard (Sceloporus clarkii vallaris) Plateau Spiny Lizard (Sceloporus clarkii vallaris)
I originally mistook these lizards for Desert Spiny Lizards, because I didn't realize that Clark's Spiny Lizards lived this far north. But it turns out that both species live in the red rock desert around Sedona, and the ones I photographed were definitely Clark's. One way to distinguish them is by the dark bands on the forearms, visible in the second photograph here.
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