Adult Female, San Luis Potosi, Mexico
BLACK-SPOTTED COLLARED LIZARD
Crotaphytus collaris – Say in James 1823
Crotaphytus collaris melanomaculatus – Axtell & Webb 1995
IDENTIFICATION:
DISTRIBUTION:
Crotaphytus collaris melanomaculatus occurs from northeast Durango eastward through southern Coahuila, northern Zacatecas, southern Nuevo Leon, central and north-central San Luis Potosi and extreme southwest Tamaulipas. In Tamaulipas, this lizard is found in the Municipios of Tula, Palmillas, Bustamante and Miquihuana.
HABITAT:
This lizard inhabits both upland and low desert sites, generally where rocks are present. It is most common on alluvial fans and the lower slopes of ridges and mountain ranges.
NATURAL HISTORY:
This species is saxicolus and is most often observed perched on rocks and rock outcrops. Male and female Crotaphytus collaris melanomaculatus display their breeding coloration in May and early June. Smaller lizards are a large part of the diet of Crotaphytus collaris. This species will bask during the heat of the day in temperatures that are too extreme for other lizards. When frightened, collared lizards have the ability to run on their hind legs (bipedal motion) for short distances.
TAXONOMY:
Some authors suggest that Crotaphytus collaris is a highly variable species with several pattern classes, but none of the various forms are sufficiently distinct enough to warrant recognition. I chose to retain use of the subspecific names until further notice.
TYPE:
Described as Crotaphytus collaris melanomaculatus by Axtell and Webb (1995). Holotype: UTEP 15915. Type locality: 3.8 km S, 1.7 km E Graseros on the highway to Presa Francisco Zarca, el 1250 m, Durango, Mexico (25 14′ 10″N, 103 47′W). An adult male collected by Eric C. Axtell on 6 July 1982.
PERSONAL NOTES:
I have seen this species on two occasions; the first was along San Luis Potosi Hwy 80 in the vicinity of Presa de Guadalupe in May 2003 where I found the above-pictured individual. When I approached her she flattened against the ground and lay motionless while I took several pictures. I had to prod her before she would take flight, but when she did it was using bipedal movement (my first experience with such behavior).
I also found this subspecies in the desert hills near Tula, Tamaulipas in August 2004. A single male was observed basking on a limestone outcrop above a small wash. Other lizards found at this locality were Sceloporus spinosus spinosus, Cophosaurus texanus, Phrynosoma modestum, Aspidoscelis colossus, Aspidoscelis inornata inornata and a single Anelytropsis papillosus.
In September, 2007 W. Farr and I sought to fill in the known distribution of this lizard in Tamaulipas; we found it abundant in the Municipios of Tula, Bustamante and Miquihuana (it was previously known from only Tula and Palmillas). We found Sceloporus cautus, S. spinosus, S. parvus, Cophosaurus texanus, Aspidoscelis colossus and Aspidoscelis inornata inornata in association with this species. We found one adult male in the Municipio de Tula that exceeded the previous maximum size record for this species by a small margin.
CONSERVATION STATUS:
This form of the Western Collared Lizard is in no danger of large or small-scale population declines; it is not protected except by general Mexican Law.
REFERENCES:
Axtell, R. W. and Webb, R. G. 1995. Two New Crotaphytus from Southern Coahuila and the Adjacent States of East-Central Mexico. Bulletin of the Chicago Academy of Sciences, Vol. 16(2):1-15.