Purple-backed Spiny Lizard

(Sceloporus magister magister)

This subspecies of desert spiny lizards occurs from the Grand Canyon south across Arizona, southern California and south into Mexico. This is the first time I've ever seen one.  It was on my front sidewalk and was about 6 in./15 cm long.

Like many desert lizards, desert spiny lizards adjust their internal temperature by changing color so they are darker during cool times, which allows them to absorb more heat from the sun, and become lighter during warm times so they reflect more solar radiation. The desert spiny lizard also uses camouflage so it is not so easily seen by predators.

Usually, during the morning hours, it will be out basking in the sun on rocks or any hard surface that is in direct sunlight (I took these photos at 10:56 am when the air temperature was a mild 82°/28°), but like many desert reptiles, it will seek shelter, usually underground in burrows or any suitable cover that provides shade, during the hottest part of the day in the summertime, as shade provides cooler temperatures than on the ground's surface. It hibernates in late fall and during the cold months of winter before re-emerging in spring.

(A different angle in extras - and both excellent  in expanded view.)