Common side-blotched lizards (Squamata: Phrynosomatidae: Uta stansburiana) can be found throughout much of the western United States and Mexico. They are abundant in arid and semi-arid regions, and are frequently encountered in rocky and sandy areas of desert shrublands and pinyon-juniper woodlands. These areas harbor sufficient quantities of small insects and other arthropods that the lizards rely on for food.
Colors and patterns vary greatly in this species, and numerous subspecies are recognized. One thing they all have in common, however, is a dark spot behind each forelimb:
Coloration is of considerable reproductive importance to side-blotched lizards. Males typically exhibit more pronounced coloration than females, and their throats are particularly relevant. Males have throats that can be orange, blue, or yellow, and these colors indicate how the males seek out mates. Orange-throated males are dominant and hoard large territories and harems of females. Blue-throated males more cautiously defend smaller territories and only one female. Yellow-throated males sneak about the edges of other males’ territories and mimic females, impregnating actual females whenever they get a chance. These different reproductive strategies result in an effective battle of “rock-paper-scissors,” with each type of strategy being superior to one while being easily defeated by the other.
Although these lizards are common, small, and seemingly unremarkable, their reproductive behaviors make them rather intriguing. As is often the case in nature, stopping to observe even the smallest of creatures can be worthwhile.