|Scientific Name:||Crotaphytus reticulatus Baird, 1858|
|Red List Category & Criteria:||Vulnerable C2a(i) ver 3.1|
|Assessor(s):||Hammerson, G.A., Lavin, P. & Mendoza Quijano, F.|
|Reviewer(s):||Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)|
Listed as Vulnerable because of the following combined factors: the overall population size probably numbers fewer than 10,000 adults; the largest subpopulation likely includes fewer than 1,000 adults; abundance is expected to decline as a result of ongoing habitat degradation.
|Range Description:||This lizard occurs in a relatively small areas in southern Texas, and Coahuila, Nuevo Leon, and Tamaulipas, Mexico (McGuire 1996). The range extends from Eagle Pass, Texas, on the north to Mission, Texas, on the southeast (Conant and Collins 1991, see Judd 1985). The Balcones escarpment of the Edwards Plateau in Texas is the northern limit of distribution, and the western distribution limit coincides with the eastern slopes of the Sierra Madre Oriental in Mexico (see Judd 1985).|
Native:Mexico; United States
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Montanucci (1976) mapped 32 collection sites in Texas and 16 in Mexico. Judd (1985) documented six locations in Texas and six in Mexico. Axtell (1989) mapped 65 collection localities in Texas. McGuire mapped 23 localities in Texas and 15 in Mexico. Dixon (2000) indicated the presence of this lizard in 11 counties in Texas.
This is the rarest of the collared lizards (Crotaphytus) in the United States. The total population size is unknown. Data from museum collections suggest a low density throughout the range; the greatest number taken at a locality at one point in time was seven (see Judd 1985). The species may be locally fairly common: six were observed at one location. The distribution tends to be patchy, with large sparsely populated or uninhabited areas (Axtell 1989).
Distribution and abundance may be declining, but distribution and population information are inadequate to assess status (A. Price pers. comm. 1997). Some small populations may be declining; the species is found infrequently but it is not endangered (R. Axtell pers. comm. 1997).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This lizard inhabits thorn-scrub vegetation, usually on well-drained rolling terrain of shallow gravel, caliche, or sandy soils. It often occurs on scattered flat rocks below escarpments or isolated rock outcrops among scattered clumps of prickly-pear and mesquite, but it also commonly ranges into mesquite flats far from the nearest rocky habitat, and in Texas it is absent on some rocky outcroppings along the margins of bluffs where other Crotaphytus species might be expected to occur. Fence posts or the branches of mesquite trees may be used a basking perches, in addition to rocks. As in Gambelia, when approached, this collared lizard often runs to the base of a shrub and remains motionless. Eggs are laid probably under large rocks or underground. Summarized mainly from McGuire (1996).|
|Major Threat(s):||In the southern part of the range, the greatest threat is habitat alteration, particularly land clearing practices, the conversion of native grazing lands to farms and improved pastures, and the planting of alien mat-forming grasses, including bufflegrass, for livestock grazing (Judd 1985, Axtell 1989, A. Price pers. comm. 1997). The introduced alien grasses degrade or destroy the preferred habitat. Buffelgrass has escaped from pastures and is common along road corridors (Judd 1985). Other potential threats include residential development and pit mining (R. Axtell pers. comm. 1997).|
|Conservation Actions:||The primary conservation need is protection of habitat from alteration.|
|Citation:||Hammerson, G.A., Lavin, P. & Mendoza Quijano, F. 2007. Crotaphytus reticulatus. The IUCN Red List of Threatened Species 2007: e.T64012A12735138.Downloaded on 21 October 2017.|