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The larger distribution range of the Short-horned Lizard extends from Montana and North Dakota, south into South Dakota, Nebraska, Wyoming, Colorado, and Kansas. In Wyoming it is found throughout most of the state at elevations below 6,500 feet and in some areas up to 7,500 feet. It inhabits the shortgrass and sagebrush communities of the prairie and desert life zones. It prefers flat terrain with firm soil (with some softer or sandy soil nearby for easy burrowing) and sparse ground-level vegetation providing easy access to sunlight.
These solitary lizards are active from May through September and into October at lower elevations. They are diurnal insectivores and feed almost exclusively on ants, using a sit-and-wait approach to ambushing their prey. (Ants play such an important role in their life that one method for locating them suggests walking in a spiral outwards from ant nests.) Although they are easily caught, they are seldom seen because of their cryptic coloration and secretive behavior—which includes sitting tight until almost being stepped on before scurrying for cover. They squirm a bit when handled and may inflate their lungs to puff up and enlarge their body. If handled roughly (Inappropriately!), they are also known to eject blood from sinuses surrounding their eyes.
They are medium sized, pudgy lizards with snout-vent lengths up to 3 inches. They have a short tail, short legs with short digits, an almost nonexistent neck (though they do have a gular fold), and their oval shaped body is squat and flattened. The dorsal background is gray, beige, or light brown with some irregularly shaped blotches of white and dark brown scattered about. The ventral surface is white. There may be areas of yellow-orange splashed about the head and the rim surrounding the lateral margin of the body.
The pug-nosed head has polygonal and conical shaped scales, some of which are greatly enlarged, keeled, and sharply pointed—forming the celebrated horns from which its surname is derived. The dorsal surface consists of small, smooth, granular scales with larger and sharply pointed scales scattered about. The scales of the legs are strongly keeled and overlapping. The ventral surface is made of smooth, non-overlapping (or slightly so), polygonal shaped scales. The lateral margin is ringed with a fringe of enlarged spiny scales.
This is the only lizard species in Wyoming that bears its young alive (viviparous). Mating occurs in early spring just after release from hibernation and courtship begins with the male displaying head bobbing behavior and licking the female’s head—the female responds in-kind if she is so enticed. The male will then bite and grasp the female’s neck and curl his tail around and underneath the female as he mounts her during copulation. The developing embryos remain in the female’s body during the following 3-month gestation period. A litter of a dozen or more babies is born in August and the offspring resemble little, inch long adults. Within an hour or two of birth, the young are moving about and feeding on their own. The female provides little or no care and soon leaves the young to fend for themselves. Males become sexually mature in their second year and females require an additional year to reach reproductive readiness.