Uta stansburiana
(Side-blotched Lizard)

Key Characteristics

Small granular scales

Gular fold

Dark blotch behind forelimbs

General Description:
Side-blotched Lizards are petite lizards that are covered with fine granular scales with the exception of the tail, which has scales that are slightly keeled.  Two other morphological characteristics of this species are the gular fold on the throat and the large interparietal scale on the top of the head.  The third eye (the parietal eyeClick word for definition) is easily located in the center of this scale.   The dorsal ground color of Side-blotched Lizards is generally a light shade of gray or tan that is sprinkled with both light and dark colored spots.  Some of these spots may be light blue on both sexes, and males often have orange sides and neck, particularly during the breeding season.  The ventral coloration of Side-blotched Lizards is more subdued, being a light cream or white.  The most obvious marking is the namesake of these lizards, and is the dark bluish-black spot that is present on the sides behind the forelimbs.  These spots are more distinct in males, but females and juveniles generally have the marking to some degree.   Overall, females and juveniles are less vividly colored than their male counterparts.

Side-blotched Lizards are the smallest lizard species in Idaho. Adults only attain snout-vent length sizes of around 54 mm (2 in.) and total lengths of 130 mm (5 in.), (Storm and Leonard 1995) with their tails being up to 1.5 times their snout-vent length (Nussbaum et al. 1983).

Side-blotched Lizards mature early and may lay two clutches of eggs during one breeding season (up to three clutches in some parts of their range) (Behler and King 1979, Nussbaum et al. 1983).  The clutches usually contain 2-5 eggs, which are laid during late April or May.  The eggs hatch in about two months (Storm and Leonard 1995).  Juveniles look like adult females (except that neonatesClick word for definition seem to have large heads for their body size).

Side-blotched Lizards inhabit arid to semi-arid regions that are vegetated with desert shrubs or pinion-juniper trees (Nussbaum et al. 1983).  These lizards can be found on a variety of substrates such as sand, gravel or loess and there may often be a rock component to the area.  In Idaho, Side-blotched Lizards often share the same rocky habitats with Western Fence Lizards.

Idaho Distribution:
Side-blotched Lizards in Idaho are found across the southwestern portion of the state.  From Washington, south to tip of Baja California and northern Mexico, and east to western Colorado and Texas.

Eats insects (frequently Hymenoptera, Coleoptera, Hemiptera, Orthoptera), spiders, scorpions, mites, and ticks. Adult males sometimes cannabalize young. In Idaho, diet may include flies, ants, and caterpillars.

HibernatesClick word for definition/aestivatesClick word for definition. Active from March to November in northern range; active all year in southern range. May aggregate during hibernation in some areas. In Idaho, species is strictly diurnal; may be active during morning and evening during hot, summer months. In Colorado study, home range size was estimated at 0.01-0.03 ha, and population density was estimated at 25-44 adults/ha. Density ranged from 11-285 individuals/ha in 7 sites in California, Nevada, Oregon, and Washington (mean density was 60/ha and 78/ha, in 2 consecutive years). Most abundant lizard in Idaho; predators include night snakes, striped whipsnakes, and raptors.

Breeding season lasts longer in southern range than in north. Female lays 1-2 clutches of 3.75 eggs (Idaho average) in March-August. Young reach sexual maturity in 1-2 yr.



Unprotected nongame species

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Important State References:
Bakewell, G., J.M. Chopek, and G.L. Burkholder. 1983. Notes on reproduction of the side-blotched lizard Uta stansburiana stansburiana in southwest Idaho. Great Basin Natur. 43:477-482.

Species description, key characteristics and original work by John Cossel Jr. © 1997
Species ecological information from Groves et al. ©1997.
Original images provided by Charles R. Peterson ©1998
Design and Optimization by Ean Harker©1999, 2000.
DAI layout by Stephen Burton, and Mike Legler © 1999.