The Mexican spotted owl (Strix occidentals lucida) is one of three subspecies of S. occidentals. The owl is about nineteen inches long, with a wingspan averaging 3.3 feet. It has brown upper-parts spotted with patches of white. The owl has large dark eyes, and lacks ear tufts. The legs and feet are fully feathered.

The Mexican spotted owl occurs in a variety of habitats, consisting of mature montane forests, shady canyons, and steep canyons. The key components in montane forests appear to be characteristics common in old-growth forests: uneven-age stands with high canopy closure and tree density, fallen logs and snags.
The Mexican spotted owl has the largest geographic distribution of any of the S. occidentals subspecies.

Historically, the owl ranged from the southern Rocky Mountains in Colorado; the Colorado Plateau in southern Utah; southward through Arizona, New Mexico, and far western Texas; in Mexico through the Sierra Madre Occidental and Oriental mountains and the southern end of the Mexican Plateau. Presently, the owl's range reflects the historic range, but owl numbers are much reduced and habitat is patchy.

Owls feed on small mammals, particularly mice, voles, and woodrats. They will also take birds, bats, reptiles and arthropods. The Mexican spotted owl is a "perch and pounce" predator, using elevated perches to find prey items using sight and sound. The owl will spend minutes, even hours, perched on a branch waiting for prey to venture near. When prey is spotted, the owl swoops down and grabs the prey with its talons. They can take prey on the wing, particularly birds. Most hunting is at night, however, there are some reports of diurnal foraging.

Mating begins mid-February to March and egg-laying follows in April to May. The owls usually use nests built by other animals. The female lays one to three eggs which are incubated for twenty-eight to thirty-two days. The young owlets fledge in June, thirty-four to thirty-six days after hatching. By October, the young are fully independent.

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: (20,000-2,500,000 square km (about 8000-1,000,000 square miles)) Range extends from southern Utah (Kertell 1977, Marti 1979) and central Colorado (Webb 1983) south through the mountainous regions of Arizona (Ganey and Balda 1989), New Mexico, western Texas (Guadalupe Mountains), northern Sonora, Chihuahua, and Nuevo Leon south to Michoacan and Puebla (AOU 1983; USFWS 1994, 1995). Mexican occurrences documented during 1990-1993 were in the Sierra Madre Occidental, Sierra Madre Oriental, and Eje Neovolcanico, south to Aguascalientes; the Mexican portion of the range has not been thoroughly surveyed (USFWS 1995). Many populations in Arizona and New Mexico occur in relatively isolated mountain ranges, sometimes separated by large expanses of nonforested habitats; little is known of the populations in many of these mountain ranges; some ranges may include too little habitat to support spotted owl populations indefinitely without periodic immigration from neighboring ranges (Ganey, in Thomas et al. 1990). Abundance (density) is greatest in the central portion of the range; a little more than half of the U.S. population occurs in the Upper Gila Mountains Recovery Unit in Arizona and New Mexico (USFWS 1995). See USFWS (1995) for a spot map showing distribution based on observations made during 1990-1993.

Historic Range:
U.S.A. (AZ, CO, NM, TX, UT), Mexico

Length: 45 cm

Differs from other subspecies in being generally paler and having the lighter markings of the underparts more whitish (Ridgway 1914).

Comments: Highest densities occur in mixed-conifer forests that have experienced minimal human disturbance (USFWS 1995, Ganey and Dick 1995). In the southwestern U.S., most common where unlogged closed canopy forests occur in steep canyons; uneven-aged stands with high basal area and many snags and downed logs are most favorable. In Arizona, occurs primarily in mixed-conifer, pine-oak, and evergreen oak forests; also occurs in ponderosa pine forest and rocky canyonlands (Ganey and Balda 1989). In Arizona, generally foraged more than or as frequently as expected (based on availability) in virgin mixed-conifer and ponderosa pine forests, and less than expected in managed forests; roosted primarily in virgin mixed-conifer forests; both foraging and especially roosting sites had more big logs, higher canopy closure, and greater densities and basal areas of both trees and snags than did random sites (Ganey and Balda 1994). In southern Utah, commonly used mesa tops, benches and warm slopes above canyons in fall and winter; relatively cool canyons were the primary summer habitat (see USFWS 1994). In New Mexico, breeding and roosting occurred in mixed-conifer forests that contained an oak component more frequently than expected by chance; generally did not use pinyon pine-alligator juniper woodlands for nesting or roosting; selected roost and nest sites in forests characterized by mature trees with high variation in tree heights and canopy closure greater than 75% (Seamans and Gutierrez 1995).

Basically intolerant of even-age forest management practices (USFWS, Federal Register, 1 April 1994). Requires cool summer roosts (Barrows 1981, Ganey et al. 1993), such as near canyon bottoms, in dense forests, on shady cliffs or in caves (Ganey et al. 1988). Sometimes occurs in deep canyons in areas that lack extensive forests. Sometimes may winter in comparatively open habitats at lower elevations. Breeding formerly occurred in desert riparian habitat, but occurrences are rare in this habitat today. In general, foraging habitat requirements are not well known (USFWS 1995). See USFWS (1993, 1994, 1995) for further details on habitat.

Nests on broken tree top, cliff ledge, in natural tree cavity, or in tree on stick platform, often the abandoned nest of hawk or mammal; sometimes in cave. In Utah and Colorado, most nests are in caves or on cliff ledges in steep-walled canyons; elsewhere, nests apparently most often are in trees, especially Douglas-fir (USFWS 1995, Seamans and Gutierrez 1995). Exhibits high level of nest site fidelity. Typically selects cool, shady sites with high canopy closure and at least a few old-growth trees, usually on moderate to steep slopes (USFWS 1993). In New Mexico, 61% of nest structures were on clumps of limbs caused by dwarf mistletoe infections; nest trees averaged 164 years old and 60.6 cm in diameter (Seamans and Gutierrez 1995). See also USFWS (1995).

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: Yes. At least some 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.

In the southwestern U.S., apparently largely nonmigratory, with some vertical migration at higher elevations (Ganey et al. 1988) (i.e., owls move to lower elevations for winter, with some exceptions). Some owls remain year-round in the same general areas but exhibit seasonal shifts in habitat use pattern (USFWS 1995). Some migrate 20-50 km between summer and winter ranges (see USFWS 1995).

Comments: Diet varies with location; woodrats, mice, and voles are common prey (USFWS 1995, Ward and Block 1995). Zion National Park, Utah: Neotoma, Thomomys, and beetles (Kertell 1977). Arizona: mainly cottontails, deer mice, woodrats, and voles (Ganey et al. 1988); also various birds, bats, lizards, and snakes (Duncan, 1992, Herpetol. Rev. 23:81). Arizona: mainly Neotoma, Peromyscus, Microtus, Sylvilagus, and Thomomys (Ganey 1992). Generally hunts from a perch. May cache prey.

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

Estimated Number of Occurrences: > 300

Comments: This subspecies is represented by a large number of occurrences (subpopulations).

1000 - 2500 individuals

Comments: In 2002, U.S. Forest Service reported 987 occupied owl sites on Forest Service lands in Arizona and New Mexico. Current information suggests there are 15 sites in Colorado, 105 sites in Utah, and 43 sites on National Park Service (NPS) lands in Arizona; in total, 1,176 sites have been identified. Based on this number of known owl sites, USFWS (2004) estimated that the total known owl numbers on federal lands in the southwestern United States at 1,176-2,352, with the higher value assuming that a pair of owls occupies each site.

Mostly solitary outside the breeding season.

Home range size apparently varies with location and habitat; generally the smallest home ranges are a few hundred hectares and the largest ones are about 1500 ha (minimum convex polygon) (see USFWS 1995). In northern Arizona, mean home range of three pairs was 847 ha; owls shifted seasonally such that year-round home range was larger than the range used during any one season (Ganey and Balda 1989). Mean home range size of four pairs in the Lincoln National Forest was 1180 ha; mean home ranges in Utah varied from 242 ha in Zion National Park to 625 ha for two owls elsewhere (see USFWS 1993). In Utah, some home ranges shifted seasonally, others did not (see USFWS 1994). In general, fidelity to territories is apparently high (USFWS 1995).

In Utah, seven juveniles dispersed 24-145 km (USFWS 1995). In New Mexico, five juvenile females dispersed 8-56 km (mean 22 km), five juvenile males dispersed 2-13 km (mean 6 km); some females, including an adult, made intermountain movements (Gutierrez et al. 1996).

Density generally is less than 0.4/sq km (mostly about 0.1-0.2/sq km) (USFWS 1995). Annual survival rate appears to be about 80-90% in adults, 6-29% in juveniles (White et al. 1995, USFWS 1995).

Comments: Roosts during the day; hunts at dusk and at night. May leave roost during day to capture prey beneath roost, retrieve cached prey, or to drink or bathe in stream. In northern Arizona, calling peaked in late spring and during 2-hour period following sunset (Ganey 1990).

Egg dates: peak in April in Arizona and New Mexico, sometimes as early as early March. Clutch size is 2-4, usually 2. Incubation, by female (fed by male), lasts about 30 days. Hatching generally occurs in early to mid-May. Young leave nest at about 5 weeks (June), fly at about 6-7 weeks, stay near nest for several weeks, fed by adults until late summer, independent by early fall (dispersal of young occurs in September-October). First breeds at 2-3 years; may not breed every year. Reproductive success generally is low (USFWS 1993); average number of young fledged per pair is about 1.0 (USFWS 1995).

Rounded Global Status Rank: T3 - Vulnerable

Reasons: Occurs in the southwestern U.S. and northern Mexico; fairly large number of occurrences; total adult population size probably is at least a couple thousand; current population trend is uncertain but apparently varies among different regions; negatively affected by historical loss, degradation and/or fragmentation of habitat, especially even-age timber management; threatened in some areas by the potential for catastrophic fire.

Intrinsic Vulnerability: Moderately vulnerable

Comments: Small clutch size, temporal variability in nesting success, and delayed onset of breeding all contribute to the relatively low fecundity of this species (Gutiérrez 1996).

United States

Rounded National Status Rank: N3 - Vulnerable

Current Listing Status Summary

Status: Threatened
Date Listed: 03/16/1993
Lead Region:   Southwest Region (Region 2) 
Where Listed:


Population detail:

Population location: entire
Listing status: T

For most current information and documents related to the conservation status and management of Strix occidentalis lucida , see its USFWS Species Profile

Global Short Term Trend: Unknown

Global Long Term Trend: Decline of 30-50%

Comments: In the mid- to late 1980s in Arizona, this owl was not detected at 27% of the historical sites that were resurveyed, indicating a possible population decline (Ganey and Balda 1989). Nevertheless, USFWS (1995) stated that "No undisputable evidence is available indicating that the population is declining or is significantly below historical levels." USFWS (1995) reported that the current distribution is nearly the same as the historical distribution, though historical occurrences in southern Mexico, in major riparian corridors in Arizona and New Mexico, and in several other specific localities have not been reconfirmed by recent surveys.

Seamans et al. (1999) studied the demography of a population in Arizona and another in New Mexico from 1991 to 1997. Survival and fecundity estimates indicated that both populations were declining at more than 9 percent per year. These estimates were corroborated by observed declines in abundance. With four additional years of data on these same populations, Gutiérrez et al. (2003; cited by USFWS 2004) concluded that the decline observed by Seamans et al. (1999) on the Arizona study area was temporary, whereas the decline in New Mexico appeared to be continuing. Wide population fluctuations may be common for populations of owls (Gutierrez et al. 2003, cited by USFWS 2004).

Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable

Comments: Primary threat has been alteration of habitat in Arizona and New Mexico as a result of even-aged timber management (USFWS 1995). Management plans for the Southwestern Region of the U.S. Forest Service include biological goals consistent with the Recovery Plan for the owl, thereby eliminating one of the primary threats (USFWS 2004).

This subspecies also may be threatened also by the potential for catastophic fire (heavy accumulations of ground and ladder fuels have rendered many forests vulnerable to stand-replacing fires) (USFWS 1995). However, noncatastrophic fires may not be detrimental. Based on data from all three spotted owl subspecies, Bond et al. (2002) hypothesized that "wildfires may have little short-term impact on survival, site fidelity, mate fidelity, and reproductive success of spotted owls. Further, prescribed burning could be an effective tool in restoring habitat to natural conditions with minimal short-term impact on resident spotted owls."

Potential for competition with and/or predation by other raptors, including great horned owl and red-tailed hawk (USFWS 1993), needs further study. See USFWS (1995) for information on the relative importance of fire and timber harvest as threats in the six U.S. recovery units.

Restoration Potential: Recovery plan (USFWS 1995) indictes that delisting could occur within 10 years (depends on results of monitoring over that period).

Preserve Selection and Design Considerations: Preserves should be distributed among the six U.S. and five Mexican recovery units designated by USFWS (1995).

This subspecies probably exists as more or less discrete clusters of populations, reflecting the patchiness of the habitat; each cluster of populations (e.g., the Mogollon Rim cluster and the Southern Rockies cluster) apparently can be regarded as a classical metapopulation; owls disperse frequently within clusters but only rarely between clusters (Keitt et al. 1995).

Management Requirements: Management initially should focus on the alleviation of major threats: catastrophic wildfire and widespread use of even-aged silviculture; thereafter, other priorities, such as creating replacement owl habitat, should be pursued (USFWS 1995, which see for detailed management information).

Manipulative experiments are needed to evaluate effects of fire (or other forest management activities) on owls (Bond et al. 2002).

See also Dawson et al. (1987) and Lefranc and Glinski (1988) for management and research recommendations. See USFWS (1994) for a review of management policies and practices by agencies and tribes.

Management Research Needs: Determine population attributes and trends in relation to existing management activities. Determine silvicultural techniques that could produce wood products and owls. Determine ways to make younger forests capable of supporting owls. Determine extent of competition with other owls.

See USFWS (1995) for detailed information on management research needs.

Global Protection: Few to several (1-12) occurrences appropriately protected and managed

Comments: About 90% of the U.S. population occurs on lands administered by the U.S. Forest Service (USFWS 1995). Logging is restricted in a number of areas in national forests, national parks, wilderness areas, and BLM lands. See USFWS (1995) for information on current protection status. USFWS (2004) designated approximately 3.5 million hectares (8.6 million acres) of critical habitat on federal lands in Arizona, Colorado, New Mexico, and Utah.

Needs: Protection of large contiguous tracts of habitat, capable of supporting multiple pairs, is the most important management need; this includes both occupied habitats and unoccupied areas approaching characteristics of nesting habitat (USFWS 1995).

Recovery plan (USFWS 1995) calls for three categories of land protection: (1) protected = 600-acre areas around occupied or recently occupied owl sites, plus forests within the owl's range that are over 40 degrees in slope, (2) restricted areas = mixed conifer and pine-oak forests outside protected areas, where logging can take place if conducted in a manner compatible with the owl's habitat, and (3) other areas = remaining forested lands; see Rinkevich (1995) for a brief overview. USFWS and USFS are to work together in carrying out the recovery plan.