Great Plains Earless Lizard

Holbrookia maculata maculata

Great Plains Earless Lizard

Distribution in Wyoming

 

 

 

 

 

 

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The distribution of the Great Plains Earless Lizard extends from South Dakota, Wyoming, and Nebraska, south through Colorado and Kansas to Oklahoma and Texas, and west into New Mexico, Arizona, and northern Mexico. It is a peripheral species in southeastern Wyoming, found at elevations below 5,500 feet in Goshen and Laramie counties. It inhabits the shortgrass communities of the prairie life zone where it prefers areas of sandy or friable soils containing sparse vegetation and open cover; it is often associated with yucca on south facing hillsides. It is active from late April into October and feeds on items such as spiders, grasshoppers, and beetles. It finds home in sheltered retreats within rodent burrows or the shredded entanglements at the base of yucca plants. It often forages some distance away from such shelters, but it is quick to make a hasty retreat or bury itself beneath the sand when alarmed or threatened.

Great Plains Earless Lizard Great Plains Earless Lizard

They are a small, short-tailed lizard with snout-vent lengths at or just under 2 inches. As their name implies, they have no external ear opening—an adaptation derived from their fossorial lifestyle. The shape of their head is a bit peculiar: the forehead is steeply sloped, the gape of the mouth is wide and extends back on to the neck, the upper lip appears rimmed and disproportionately enlarged, and they seem to be missing a chin. They have a gular fold. The small granular scales of the back become polygonal shaped and slightly larger along the sides and on to the belly. The scales on the leading or anterior portion of the legs are pointed and slightly overlapping. The dorsal background is gray and brown with a wide, pale gray midline stripe and a pair of narrower and lighter lateral stripes. Lying between the midline and lateral stripes is a series of dark brown bars or blotches which run from the back of the head and extend along the body and down on to the tail. The belly and throat are white.

Great Plains Earless Lizard Great Plains Earless Lizard

These lizards are distinguished from Prairie Lizards by having a narrower and less distinctive gray midline stripe and by lacking the well defined white dorsolateral stripes. They are identified from Sagebrush Lizards by lacking the front shoulder patch and black-white-black striping on the back of the thigh.

Great Plains Earless Lizard Great Plains Earless Lizard

Mating and courtship occurs in early spring and 2-7 eggs per clutch are laid in June; a second clutch may be laid in July. Older and larger females produce larger clutches. Both sexes have two (occasionally three) black spots on the sides just behind the front legs; these are bordered with a bluish outline in males. Females in breeding condition have yellow-orange on the sides of the head, neck, and body. Hatchlings appear from August into September. Sexual maturity is reached in the 2nd year.