endemic to a single state or province
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: According to Leaché and Reeder (2002), the range of Sceloporus cowlesi includes southern and eastern Arizona, New Mexico, western Texas, and northern Chihuahua, Mexico. Leaché and Reeder (2002) provided only coarse-scale range maps and did not include distributional details for areas where the range of this species adjoins or approaches the ranges of S. consobrinus or S. tristichus. Leaché and Cole (2007) documented hybridization between S. cowlesi and S. tristichus in Arizona.
Habitat Type: Terrestrial
Comments: Habitat in most areas consists of openly wooded, shrubby, or rocky areas. Usually these lizards are in open/sunny situations.
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.
Comments: Diet is dominated by insects, spiders, and other arthropods.
Number of Occurrences
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 a large number of occurrences (subpopulations) and locations (as defined by IUCN).
100,000 to >1,000,000 individuals
Comments: Total adult population size is unknown but very large.
Life History and Behavior
Comments: These lizards are inactive during cold periods and during the hottest part of day in summer.
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Global Short Term Trend: Relatively stable (=10% change)
Comments: Trend over the past 10 years or three generations is uncertain, but distribution and abundance likely have been relatively stable.
Names and Taxonomy
Comments: Sceloporus cowlesi formerly was included in S. undulatus. The traditionally recognized Sceloporus undulatus is morphologically highly variable (e.g., see Stebbins 1985, Conant and Collins 1991, Hammerson 1999). Recent genetic studies indicate that the species comprises multiple species that do not conform with traditionally recognized subspecies.
Leaché and Reeder (2002) examined range-wide mtDNA variation and identified at least four apparently monophyletic (but morphologically highly variable) groups, which they proposed as species under the evolutionary species concept (Eastern group: east of Mobile Bay; Central group: east of the Rockies and west of Mobile Bay; Western group: southern Wyoming to central Arizona and northern New Mexico; Southwestern group: eastern Arizona and central New Mexico to northern Mexico and western Texas). All of the groups are discordant with recognized subspecies circumscriptions. For example, the Central group encompasses six nominal subspecies ranging from the foothills of the Rocky Mountains in Colorado to the Gulf Coast of southern Mississippi. Populations of the morphologically distinctive subspecies erythrocheilus in central Colorado grouped with subspecies garmani (Central group) rather than with populations of erythrocheilus in south-central Colorado (Western group). Leaché and Reeder (2002) tentatively proposed the following names: eastern group, S. undulatus; central group, S. consobrinus; western group, S. tristichus; southwestern group, S. cowlesi. However, Leaché and Reeder identified no diagnostic characters for any of the proposed species, and the distributions of proposed species were only coarsely mapped and do not correspond closely with the distributions of previously recognized subspecies, leaving in doubt the specific identities of many Sceloporus populations.
Further integrated study of genetic variation, using mitochindrial and nuclear DNA, and more detailed genetic examination of various geographic areas (Niewiarowski et al. 2004; Leaché and Cole 2007; Leaché 2009) has helped clarify relationships among "S. undulatus" populations. Recognition of the four species proposed by Leaché and Reeder (2002) seems to be a justifiable change in the treatment of this complex, but the precise distributions of the taxa near some clade boundaries remain problematic. Leaché and Cole (2007) acknowledged the challenges imposed by apparent decoupling of morphological, karyotypic, and mtDNA divergence that may occur among populations in this complex and noted that conclusions about the number of species in the S. undulatus complex are directly linked to the particular "threshold' one imposes to define species status.
Leaché and Cole (2007) presented evidence for hybridization between S. cowlesi and S. tristichus in an ecotone in eastern Arizona.
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