The Sagebrush Lizard, Sceloporus graciosus, is a small reptile widely distributed across the western United States, primarily inhabiting the arid, open shrub-steppe regions dominated by sagebrush. Its diet is highly specialized yet opportunistic, consisting almost entirely of invertebrates. These food sources provide necessary energy, nutrients, and a significant portion of the lizard’s moisture requirements in its dry habitat. Understanding the specific types of prey consumed is key to appreciating this species’ role within its ecosystem.
The Core Diet: Arthropods and Insects
The Sagebrush Lizard is an insectivore, primarily consuming arthropods and insects found within its immediate surroundings. A major staple of its menu is ants, which are consumed in large quantities and form a substantial part of the lizard’s caloric intake. Beyond ants, the lizard preys on a wide variety of other invertebrates, including small beetles, grasshoppers, and spiders.
Other common food items include flies, cicadas, planthoppers, and small caterpillars. The diet is opportunistic, incorporating nearly any small, slow-moving arthropod the lizard can subdue. Smaller prey items like ticks and mites are also regularly consumed, providing sustenance in habitats where larger insects may be scarce. In rare instances, cannibalism has been documented, with adults sometimes preying on newly hatched juveniles.
Hunting and Foraging Strategies
The Sagebrush Lizard utilizes a “sit-and-wait” or ambush predation strategy to acquire its food. These lizards are diurnal, spending much of their time basking on rocks, logs, or low branches to regulate their body temperature. This basking position simultaneously serves as a strategic hunting post.
From this stationary perch, the lizard maintains vigilance, waiting for prey to pass within striking distance. Once prey is identified, the lizard employs a rapid burst of speed to capture it. This hunting method conserves energy compared to actively searching, which is beneficial where food resources are spread out. Foraging is often restricted to the immediate area surrounding their basking or refuge sites, ensuring quick access to cover.
Dietary Shifts: Age and Season
The composition of the Sagebrush Lizard’s diet changes depending on the lizard’s age and the time of year. Juvenile lizards are constrained by their body size, leading them to consume smaller, softer-bodied prey. Their early diet often focuses on minute organisms like mites and smaller insect larvae that are easier to capture and swallow.
As the lizards mature, they shift their focus to larger and sometimes harder-shelled prey, such as adult beetles and larger spiders. Seasonality also dictates prey availability and the lizard’s energy demands. The lizards are active from approximately March or April through September or October, after which they enter brumation. Increased feeding activity in the late summer and fall is necessary to build up fat reserves required to survive the cold months, coinciding with the peak abundance of insect populations.