Currently, there are 10 recognized subspecies of Urosaurus ornatus, but the subspecies population distinction is losing favour (Alva 2014) as many researchers consider no population of U. ornatus distinct enough for subspecies status (Bartlett and Bartlett 2013). Many of the characteristics used for species differentiation are variable and shared among purportedly distinct subspecies (Bartlett and Bartlett 2013).

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.

The Common or Ornate Tree Lizard (Urosaurus ornatus) is native to North America and considered one of the most widespread and abundant lizard species (Dunham 1982), ranging broadly across the western United States through central Mexico, from sea level to 2,440 m in elevation (Jones and Lovich 2009). In the United States, its range boundary extends from extreme southwestern Sweetwater County, Wyoming near the state line (Baxter and Stone 1985), southeast to Texas, and west to extreme southeast California (Behler and King 1979). Therefore, U. ornatus occurs in the following U.S. states: Arizona, California, Colorado, Nevada, New Mexico, Texas, Utah, and Wyoming. In Mexico, the species ranges across northern Mexico, from northeast Baja California to Tamaulipas, extending southward to Durango and the west side of the Sierra Madre Occidental into Sinaloa. The species occurs in the following Mexican states: Baja California, Chihuahua, Coahuila, Durango, Nuevo León, Sinaloa, Sonora, and Tamaulipas.

The broad geographic range of U. ornatus suggests that it may be found in numerous locations and its extent of occurrence (EOO) and area of occupancy (AOO) are very large. Range extensions may be occurring along the southwestern border between Texas and Mexico, but presence records in this region are inconsistent.

While species-level population data are lacking, it is considered to have a large stable population with many subpopulations. There is no data to suggest that Urosaurus ornatus exhibits a severely fragmented population or that it exhibits extreme fluctuations in the number of mature individuals within a population or in the number of subpopulations. Most parts of the species' range have large subpopulations that are considered stable, although individuals may easily be overlooked due to their small size and cryptic colouring (Bartlett and Bartlett 2013).

Urosaurus ornatus is a small-bodied, diurnal lizard species that is active throughout the year in some parts of its range (Asplund and Lowe 1964). In the northern portion of its range, U. ornatus occupies burrows or crevices and becomes inactive from November through March (Hammerson 1982). However, in southern portions of the range at lower elevations they can be active year-round (Parker 1973, Ballinger 1977). Animals may also aestivate during drought or periods of high temperatures to minimize water loss (Jones and Lovich 2009).

This species exploits arid and semiarid environments including subalpine conifer forests, rocky slopes (Marlow 1988), canyons, cliffs, wooded grasslands, riparian scrub, and ephemeral riparian woodlands (Jones and Lovich 2009, Lazaroff et al 2006) often near streams and dry washes (Behler and King 1979). Within these environments, tree lizards typically exploit living trees, snags (dead trees, fallen or standing), or boulders and canyon walls (Jones and Lovich 2009, Smith 1995, Taylor et al. 2018, Lattanzio 2022) that offer plenty of features on which to climb (Holycross et al. 2022). Based on several studies, U. ornatus seem to prefer trees and boulders over other microhabitat types (Zucker 1989, Smith 1995, Herrel et al 2001, Lattanzio 2022).

The species is most readily observed in the morning and late afternoon basking and/or foraging for prey items (Behler and King 1979). Foraging trips to the ground are typically brief (Conant and Collins 1991) and end with a quick retreat to a higher perch (Smith 1995). Prey items for this species consist of invertebrates including aphids, thrips, plant lice, beetles, flies, true bugs, ants, termites and spiders (Hanson and Hanson 1997, Lattanzio and Miles 2016). It is preyed upon by small carnivorous mammals, raptorial birds, larger lizards, and snakes (Jones and Lovich 2009). This species may also be outcompeted in parts of its range by other lizards such as Canyon Lizard (Sceloporus merriami; Dunham 1980) and Striped Plateau Lizard (Sceloporus virgatus; Smith and Ballinger 1994).

When not actively foraging, this species typically perches in a vertically oriented position with its head facing upward or downward (Conant and Collins 1991). Although their cryptic coloration makes them difficult to see, individuals will typically reveal themselves through territorial displays such as head bobbing (Conant and Collins 1991). Males and females of this species are territorial and exhibit a throat colour polymorphism, with the range of colour expression varying among subpopulations (Zucker 1989, Hews et al. 1997, Lattanzio 2022). Evidence suggests that these patterns are genetically based and fixed at maturity (Thompson et al. 1993). Colour expression seems to primarily signal alternative mating strategies: males with blue coloration tend to be aggressive and territorial, orange males tend to be nomadic, and yellow males act as satellites and typically usurp resources within a blue male’s territory (Lattanzio and Miles 2014). However, recent findings suggest potentially strong associations between throat colour expression and climate tolerance, contributing to variation in population morph composition throughout their range and over time (Lattanzio 2022).

Tree lizards are short-lived, oviparous, and early maturing (Tinkle et al 1970), with age of maturity ranging from ~1.2–2.2 years (Dunham 1982, Tinkle and Dunham 1983). While three years is reported its typical lifespan (Deslippe et al. 1990b, Easterbrook and Smingler 2009), some mark-recapture studies have recoded tree lizards as old as 5–6 years old (Lattanzio, unpublished data). This discrepancy is in large part due to mortality variation among populations which ranged from 66-77% annual adult mortality and 87–99% juvenile mortality (Dunham 1982) across four geographically isolated populations.

The species displays a variety of mating systems dependent on habitat (M’Closkey et al. 1990), but a polygynous mating system (Milstead 1970, M’Closkey et al 1990b) where males may mate with more than one female is most commonly reported. Monogamy and polygamy have been reported when tree lizard population densities are low in the habitat (Villaverde and Zucker 1998). Mating takes place throughout spring and summer (Holycross et al 2022) but is most common in late May and June (Asplund and Lowe 1964). From April to September (Behler and King 1979), but primarily in July (Asplund and Lowe 1964), they will lay 1–6 clutches of 2–16 eggs each (Tinkle and Dunham 1983, Brennan and Holycross 2006) underground or under rocks (Deslippe et al 1990a). Hatchlings emerge from May to September (Jones and Lovich 2009). Females of this species can facultatively retain eggs for at least 29 days past the normal time of oviposition (Mathies 1999) and store sperm (Villaverde and Zucker 1998) to guard against unfavourable conditions.

There are no current major threats to this species across much of its range. Minor threats may occur from urbanisation and climate change in some parts of this species’ range. In some parts of its range, Urosaurus ornatus is unaffected by urbanisation (French et al. 2008) and was the most common lizard in urban environments in a study of seven native lizard species in Phoenix, Arizona (Ackley et al. 2015). However, this pattern does not always hold. For instance, in northern Wyoming the population is considered imperilled due to significant habitat loss and continuing loss due to energy (oil and gas) development (Wyoming Game and Fish Department 2017).

The species is not known to be used or traded. It has historically been a well studied species for ecology and evolution research.

This species is widespread and known to occur in multiple protected areas and national parks across its range. There are no species specific conservation measures for this species in most parts of its range. However, conservation measures are in place for the species in northern Wyoming that consist of population surveying and monitoring of population distribution, status, and habitat associations (Wyoming Game and Fish Department 2017).

Research on this species typically concentrates on its reproductive and thermal biology. Females of this species are understudied as compared to males. Future research may be needed to identify the response of this species to climate change.