This diurnal lizard emerges in the morning and basks in the sun to raise its body temperature before foraging for food (8). Chuckwallas are primarily herbivorous, feeding on a variety of fruit, leaves, buds, succulent stems and flowers (8), with some species supplementing their diet with the occasional insect (7). When danger is sensed, chuckwallas display a unique defensive strategy of evading a potential predator. The threatened animal scurries into a rock crevice wherein it firmly lodges itself by inflating its lungs, thereby making removal by a predator almost impossible (5) (8).
Relatively little is known about the reproductive biology of the San Esteban Island chuckwalla. Chuckwallas generally lay a clutch of between 5 and 16 eggs in June to perhaps August, although some females may not lay eggs every year (7).