BANDED ROCK LIZARD
Petrosaurus mearnsi – Stejneger 1894
IDENTIFICATION:
DISTRIBUTION:
Petrosaurus mearnsi is found in Baja California Norte, from the US border south along the eastern face of the Sierra Juarez, through the Paso de San Matias (where it narrowly ranges into the western foothills if the Sierra San Pedro Martir) to the Sierra Las Pintas and ultimately to the Bahia de los Angeles region (the exact southern limit of its range is unknown). Isolated populations occur on Isla Miramar (Isla del Muerto) in the northern Gulf of California and on El Pedregoso, a massive rockpile along Hwy 1 south of Catavina. Elevational distribution from near sea level to around 1,200 meters.
HABITAT:
This species occurs in boulder-fields, rocky canyons and rock outcrops of low to high desert habitats. It is also found in a narrow zone of chaparral and pinon-juniper woodland on the western slopes of the Sierra San Pedro Martir.
Rocky Habitat, 1,200′, Baja California, Mexico
Rocky Canyon habitat, 300′, Baja California, Mexico
Rocky desert habitat, Baja California, Mexico
Boulder microhabitat, 1,500′, Baja California, Mexico
NATURAL HISTORY:
P. mearnsi is active from March-October. It is diurnal and almost always seen basking or foraging on boulders or rocky cliffs. At night these lizards can be found sleeping upside-down on the undersides of boulders, or within cracks on rock faces. They are insectivorous and reproduce in the spring; hatchlings appear in the late summer/early fall.
TAXONOMY:
This species is closely related to the island endemic P. slevini.
TYPE:
Described as Uta mearnsi by L. Stejneger (1894). Holotype: USNM 21882. Type locality: “Summit of Coast Range, United States and Mexican boundary line [San Diego County], California.”
PERSONAL NOTES:
I have seen this lizard on many occasions in both the Catavina region of Baja California, and throughout the desert slopes of eastern San Diego and western Imperial Counties, California. At Mortero Wash I found this species occuring very densely on granite rockpiles, and witnessed lizards foraging on the earth near the base of the piles. At Mountain Springs (I-8 grade) I often found this species asleep on the underside of boulders while I was searching for Phyllodactylus nocticolus and Xantusia henshawi.
CONSERVATION STATUS:
This species is abundant, widespread, and in no need of special protection.
REFERENCES:
Stejneger, L. 1894. Description of Uta mearnsi, a new lizard from California. Proceedings of the United States National Museum 17:589-591.
Van Denburgh, J. 1922. The reptiles of western North America. Proceedings of the California Academy of Sciences , Vol. 1-2:1-1028.