This species is found just west of Fort Worth and Austin to the eastern Trans-Pecos area in Texas and into Arizona and Northern Mexico. C. texanus is absent from the eastern part of Texas, the Lower Rio Grande Valley and the Panhandle (Bartlett and Bartlett 1999).

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) The range extends from Arizona across most of southern New Mexico to northern Texas, and south to northern Zacatecas and San Luis Potosi, and western Tamaulipas, Mexico (Degenhardt et al. 1996, Bartlett and Bartlett 1999, Dixon 2000, Stebbins 2003). Elevational range extends from near sea level to about 2,100 meters (6,890 feet) (Stebbins 2003).

This lizard ranges from about 2 and 3/4 to 7 and 1/4 inches from snout to tip of the tail (Barker and Garrett 1987). However, females are smaller than males. Skin coloration depends on habitat but the dorsal ground color is usually from gray to brown to reddish with head, tail, body and legs sprinkled with small light spots. The tail is mostly black underneath with dark bars on top and on the limbs of the animal. The male and female are sexually dimorphic: the male has two distinct black lines in a field of blue and yellow, anterior to the hind legs that wrap onto the venter and stop abruptly. The females and juveniles of the species have a distinct dark stripe on the back side of each thigh, surrounded by a lighter color. Pregnant females take on a pink coloration on their flanks. In both sexes, the tail and body are slightly flattened and no external ear openings are present (hence, their common name) (Bockstanz and Cannatella 1998). C. texanus has two throat folds, fairly large eyes and twenty-seven or fewer feomoral pores. They are also characterized as having shorter forelegs than hind legs and fairly long toes (Barker and Garrett 1987).

Length: 18 cm

• Terrestrial

Cophosaurus texanus texanus is a terrestrial lizard which inhabits rocky areas such as desert flats, streambeds and limestone cliffs (Barker and Garrett 1987). Juveniles use rock perches more frequently than adults .

Terrestrial Biomes: desert or dune

Comments: The habitat includes gravelly to rocky substrates in deserts with scattered to moderate vegetative cover (e.g., sparse cactus, mesquite, ocotillo, creosote bush, or paloverde), often along floodplains, arroyo edges, and similar topographic features (Degenhardt et al. 1996, Stebbins 2003). Eggs are laid underground (Smith 1946).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

The Texas earless lizard is an insectivore, eating both adult and larval forms of insects such as beetles and grasshoppers (Barker and Garrett 1987). Juvenile earless lizards consume smaller prey items than do adults. This may be attributed to the inability of juveniles to handle large prey items.

Comments: Eats insects and other invertebrates. See Maury (1995, Journal of Herpetology 29:266-272) for diet in the central Chihuahuan Desert in Mexico.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: This species is represented by many occurrences that are well distributed throughout the range. Degenhardt et al. (1996) mapped well over 100 collection sites in New Mexico, and Dixon (2000) mapped this species as occurring in more than 100 counties in Texas.

100,000 - 1,000,000 individuals

Comments: Total adult population size is unknown but likely exceeds 100,000. Densities of 10 to 107 individuals per hectare have been recorded in New Mexico and Texas (Howland 1992, Degenhardt et al. 1996). The species is common in Texas (Bartlett and Bartlett 1999).

Comments: Most active 0900-1300 h in Arizona (Smith et al. 1987). Hibernates December-February in western Texas, late October to mid-March in New Mexico (Sugg et al. 1995).

The eggs of C. texanus are laid from March to August and take about fifty days to hatch (Bartlett and Bartlett 1999). Some evidence suggests that these lizards may lay three clutches in a season (Howland 1992). The young are precocial and are about two inches long at hatching. The Texas earless lizard rarely reaches two years of age in the Central Texas area (Howland 1992).

Oviposition season begins in April or May, extends into August. Egg laying evidently peaks in late May in New Mexico; hatchlings first appear in late June or early July in western Texas, in mid-July in New Mexico (Sugg et al. 1995). Clutch size averages 3-4 in Arizona (Smith et al. 1987), 3.2-6.1 in several areas in Texas. Two or more clutches/year in Arizona, 3-5 or more in Texas. Sexually mature by end of first year; most reproduction is by yearlings (Sugg et al. 1995). See Howland (1992).

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Moderately vulnerable

Global Short Term Trend: Relatively stable (=10% change)

Comments: Extent of occurrence, area of occupancy, and population size are large and appear to be relatively stable.

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: No major threats have been identified. Habitat loss and degradation resulting from agricultural, residential, and commercial development likely have caused localized declines.

Comments: This species was formerly placed in the genus Holbrookia.