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: (20,000-200,000 square km (about 8000-80,000 square miles)) This species is resident in southwestern California (north to Los Angeles County, formerly to Ventura County) and northwestern Baja California, south locally to southern Baja California (including Santa Margarita and Espiritu Santo islands) (AOU 1983), mostly at elevations below 500 meters. The species apparently no longer occurs in Ventura County (California), and its once extensive distribution in Los Angeles County is now reduced to a small portion of the Palos Verdes Peninsula.

Length: 11 cm

Weight: 6 grams

Differs from black-tailed gnatcatcher in being grayer below and having less white on the underside of the tail. Differs from the blue-gray gnatcatcher in having a less conspicuous eye ring and and dull gray rather than more whitish underparts. See Dunn and Garrett (1987) for detailed treatment of field identification of this and other North American gnatcatchers.

• Terrestrial

Habitat Type: Terrestrial

Comments: Habitats include coastal sagebrush and thorn forest, desert brush, and scrub, especially in mesquite and creosote-bush (AOU 1989), on dry coastal slopes, along washes, and on mesas; areas of low plant growth (about 1 meter high). In California, this gnatcatcher occurs in several distinctive subassociations of the coastal sage scrub plant community, especially those dominated by Artemisia californica (Atwood 1992). Generally it avoids crossing even small areas of unsuitable habitat (Atwood 1992). Nests are in shrubs.

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: Gleans insects and spiders from foliage and twigs.

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

Estimated Number of Occurrences: 21 to >300

Comments: Occurrences have not been circumscribed using standardized criteria, but this species certainly is represented by a large number of occurrences (subpopulations), or at least by a substantial number of relatively large occurrences.

10,000 - 1,000,000 individuals

Comments: Population in the United States is likely around 3,000 pairs (Atwood and Bontrager 2001). Abundance in Baja California is undetermined, but Atwood (1993) stated that most of the species' population is in central and southern Baja California and that the species is "common" there, and Zink et al. (2000) characterized Baja populations as "dense and continuously distributed throughout the peninsula." Thus the breeding population in Baja California is likely to be much larger than 3,000 pairs.

Home range may be as small as 0.8 hectares in high quality habitat, as large as 5.6 hectares in inland areas with relatively sparse vegetation (Atwood 1992). Territories generally 1.6 to 4.4 hectares (Atwood 1993).

California: breeds from late February through mid-July, with most initial nesting attempts from mid-March through early April; clutch size averages 3.8; incubation by both sexes, about 14 days; nestling period about 16 days; reproductive success often poor due to predation or parasitism by brown-headed cowbird (Atwood 1992).

United States

Rounded National Status Rank: N2 - Imperiled

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Has declined in range and abundance at the northern end of the range in southern California, due mainly to loss and fragmentation of habitat by urban/residential development; in Baja California, where the vast majority of the global population occurs, the species is common and not significantly threatened.

Global Short Term Trend: Relatively stable to decline of 30%

Global Long Term Trend: Increase of 10-25% to decline of 50%

Comments: Substantial habitat has been eliminated in southern California, whereas relatively little habitat has been lost in Baja California, except in the north. The most optimistic assessment of habitat loss is southern California concluded that current coastal sage scrub habitat (as of the early 1990s) was 66 percent of the historical level (Michael Brandman Associates 1991, cited by Atwood and Bontrager 2001). In contrast, Westman (1981) stated that coastal sage scrub in southern California had been reduced to 10-15 percent of its former extent by the early 1980s. Atwood and Bontrager (2001) interpreted avilable information as indicating that about 70-90 percent of the original habitat in southern California had been eliminated. Atwood and Bontrager (2001) cited an unpublished 1993 USFWS report stating that habitat loss in southern California was 33 percent since 1993. Because most of the gnatcatcher's habitat is in Baja California, the range-wide long-term trend is at worst a moderate decline.

Degree of Threat: A : Very threatened throughout its range communities directly exploited or their composition and structure irreversibly threatened by man-made forces, including exotic species

Comments: Remaining populations in southern California are highly fragmented by urban development, which has destroyed much coastal sage scrub habitat. Intense housing development and construction or expansion of transportation corridors in Orange, Riverside, and San Diego counties, California, threaten remaining large tracts of habitat (Atwood 1992, Small 1994). However, "given the scope of conservation measures currently being undertaken in coastal southern California, prognosis for the species' continued persistence is good" (Atwood and Bontrager 2001).


With increased habitat fragmentation, parasitism by the brown-headed cowbirds has become a threat (Atwood 1992).

Wildfires periodically eliminate (temporarily) significant areas of gnatcatcher habitat (Small 1994).

Biological Research Needs: See Atwood and Bontrager (2001).

Global Protection: Few (1-3) occurrences appropriately protected and managed

Comments: USFWS (2007) designated as critical habitat approximately 79,846 hectares of habitat in San Diego, Orange, Riverside, San Bernardino, Los Angeles, and Ventura counties, California. Small populations are found in some publicly owned preserves (Willick and Patten 1992) and certain military bases (e.g., Camp Pendleton Marine Corps Base) (Steinitz et al. 1996). This species is an element in a large number of habitat conservation plans.

Needs: Protection of intact habitat of sufficient size to support viable populations is urgently needed, but this is difficult and expensive because of the high human demand for land in coastal southern California.

Mechanical and manual removal of invasive exotic plants is an important aspect of habitat restoration in some cases (Atwood and Bontrager 2001).

Comments: This species formerly was included in P. melanura (AOU 1989, Atwood 1988, 1991). Although morphological studies have led to the recognition of various subspecies (e.g., Atwood 1991, Mellink and Rea 1994), these have been controversial. Moreover, range-wide genetic analyses (Zink et al. 2000) indicate that northern populations of P. californica are not differentiated from southern populations and that the pattern of genetic variation is inconsistent with the recognition of proposed subspecies.