Urosaurus ornatus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Phrynosomatidae

Scientific Name: Urosaurus ornatus (Baird & Girard, 1852)
Common Name(s):
English Ornate Tree Lizard, Tree Lizard

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2007
Date Assessed: 2007-03-01
Assessor(s): Hammerson, G.A., Frost, D.R. & Santos-Barrera, G.
Reviewer(s): Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)
Listed as Least Concern in view of the large and stable extent of occurrence, area of occupancy, number of subpopulations, and population size. No major threats are known.

Geographic Range [top]

Range Description:The geographic range extends from southwestern Wyoming (Baxter and Stone 1985), Utah, western Colorado (Hammerson 1999), southern Nevada, southeastern California, Arizona, New Mexico (Degenhardt et al. 1996), and Texas (Dixon 2000) to northeastern Baja California (Grismer 2002), Sinaloa, northern Coahuila (Stebbins 2003), and Tamalipas. Elevational range extends from sea level to around 2,770 m (9,000 feet) (Stebbins 2003).
Countries occurrence:
Mexico; United States
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This species is represented by a very large number of occurrences or subpopulations (e.g., see maps in Degenhardt et al. 1996 and Hammerson 1999). The total adult population size is unknown but surely exceeds 100,000. The extent of occurrence, area of occupancy, number of subpopulations, and population size are large and basically stable.
Current Population Trend:Stable
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:Habitat includes a wide range of situations from desert to the lower edge of the spruce-fir zone; usually this lizard perches on massive rocks or trees (mesquite, oak, pine, juniper, alder, cottonwood, tamarisk, rough-bark eucalyptus) (Hammerson 1999, Stebbins 2003), sometimes on fence posts or buildings. It is often associated with river courses. When inactive, it occurs in tree stumps, under bark, in rock crevices, in burrows, or similar protected sites. It lays eggs probably in soil/underground, or under rocks.

Threats [top]

Major Threat(s): No major threats have been identified.

Conservation Actions [top]

Conservation Actions: This species occurs in a large number of protected areas, such as national parks, monuments, and wilderness areas. No direct conservation measures are currently needed for this widespread and adaptable species.

Classifications [top]

1. Forest -> 1.4. Forest - Temperate
1. Forest -> 1.5. Forest - Subtropical/Tropical Dry
3. Shrubland -> 3.4. Shrubland - Temperate
3. Shrubland -> 3.5. Shrubland - Subtropical/Tropical Dry
3. Shrubland -> 3.8. Shrubland - Mediterranean-type Shrubby Vegetation
0. Root -> 6. Rocky areas (eg. inland cliffs, mountain peaks)
8. Desert -> 8.1. Desert - Hot
8. Desert -> 8.2. Desert - Temperate

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
In-Place Species Management
In-Place Education

Bibliography [top]

Ballinger, R.E. 1983. Life-history variation. In: R.B. Huey, E.R. Pianka and T.W. Schoener (eds) Lizard Ecology: Studies of a Model Organism, 241-260. Harvard University Press, Cambridge, Massachusetts.

Baxter, G.T. and Stone, M.D. 1985. Amphibians and Reptiles of Wyoming. Second Edition. Wyoming Game and Fish Department, Cheyenne, Wyoming.

Degenhardt, W.G., Painter, C.W. and Price, A.H. 1996. Amphibians and Reptiles of New Mexico. University of New Mexico Press, Albuquerque, New Mexico. Xix + 431 pp.

Dixon, J.R. 2000. Amphibians and Reptiles of Texas. With Keys, Taxonomic Synopses, Bibliography, and Distribution Maps. Second edition. Texas A & M University Press, College Station, College Station, Texas.

Dunham, A.E. 1982. Demographic and natural history variation among populations of the iguanid lizard Urosaurus ornatus: implications for the study of life-history phenomena in lizards. Herpetologica 38: 208-221.

Dunham, A.E. 1983. Realized niche overlap, resource abundance, and intensity of interspecific competition. In: R.B. Huey, E.R. Pianka and T.W. Schoener Lizard Ecology: Studies of a Model Organism, pp. 261-280. Harvard University Press, Cambridge, Massachusetts.

Dunham, A.E., Miles, D.B. and Reznick, D.N. 1994. Natural history patterns in squamate reptiles. In: C. Gans and R.B. Huey Biology of the Reptilia. Volume 16: Ecology B, Defense and Natural History, pp. 441-522. Branta Books, Ann Arbor, Michigan.

Grismer, L.L. 2002. Amphibians and Reptiles of Baja California, Including its Pacific Islands and the Islands in the Sea of Cort├ęs. University of California Press, Berkeley and Los Angeles, California.

Hammerson, G.A. 1999. Amphibians and reptiles in Colorado. Second edition. University Press of Colorado, Boulder, Colorado.

IUCN. 2007. 2007 IUCN Red List of Threatened Species. Available at: (Accessed: 12th September 2007).

Mittleman, M.B. 1942. A summary of the iguanid genus Urosaurus. Bulletin of the Museum of Comparative Zoology 91: 103-181.

Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians. Third Edition. Houghton Mifflin Company, Boston, Massachusetts.

Wiens, J.J. 1993. Phylogenetic systematics of the tree lizards (genus Urosaurus). Herpetologica 49: 399-420.

Citation: Hammerson, G.A., Frost, D.R. & Santos-Barrera, G. 2007. Urosaurus ornatus. The IUCN Red List of Threatened Species 2007: e.T64174A12750887. . Downloaded on 25 June 2018.
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