Wednesday

Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)

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This page last updated on 02/09/2019
EFP-P1010233
(Fig. 01)
Picture Notes: On 05/23/13, my last find of the day was my first sighting of a horned lizard (Fig. 01). I found him sitting right in the middle of the hiking path on a scenic turnoff/overlook area on the western side of Lovell Canyon Road. After learning that their maximum length is generally less than six inches, it appeared that this was full-grown adult. After posing for several minutes  so we could capture pictures, he finally ran off into the bushes. On my return, I located him once again, hiding in the shade beneath a bush (Fig. 02), only about five feet from our initial sighting. Again he appear quite camouflaged.
             
Description: The Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum), is a species of diverse lizards that are adapted to life in hot, sandy deserts. They are often referred to as "horny toads", although they are not toads, but lizards. This species of lizard has a distinctive flat body with one row of fringe scales down the sides. The horns on their heads are wide at the base. The two longest horns are long and set close together (horn length usually more than 45% of the head length; space between the bases about half of the width of the horn at the base) and the tip of the tail is more flat.They have one row of slightly enlarged scales on each side of the throat. In addition to the horns on their head, Desert Horned Lizards also have many small horn-like scales on their dorsal surface, and these scales form a single row that fringes the sides of these lizards. Colors can vary and generally blend in with the color of the surrounding soil, but they usually have a beige, tan, or reddish dorsum with contrasting, wavy blotches of darker color. They have two dark blotches on the neck that are very prominent and are bordered posteriorly by a light white or grey color. They are capable of attaining a snout-vent length of 3.75 inches with a total length of 5.5 inches. They primarily feed on ants, beetles and their larvae, and plant material. They can often be found near anthills where they sit and wait for passing ants. Predators include Prairie Falcons, Loggerhead Shrikes, longnose leopard lizards, and striped whipsnakes.
              
Its range is from southern Utah and Nevada to southeast California, western Arizona, and northern Baja California at elevations from below sea level to 7,000 feet. Found in extremely diverse habitats ranging from areas of fine sand to rocky or gravelly habitats of arid to semiarid plains, hills and lower mountain slopes. Sticking mostly to low-desert habitats, especially Creosote-Bursage Flats and Mojave Desert Scrub habitat types with sandy areas  they are typically found among woody shrubs, cacti, and yucca on sandy flats, alluvial fans, washes, and dunes below about 6,500 ft. Also found in Mesquite-Catclaw areas, salt desert scrub, and Pinyon-Juniper Woodland habitats. Sandy soil is preferred for burrowing but they can also found in sandy-gravelly drainage channels.  They emerge usually in March in southern Nevada, with little evident adult activity after mid-July. They are generally inactive and buried in soil at night.
             
EFP-P1010247
(Fig. 02)