Species: Spizella breweri

Brewer's Sparrow

Species

Birds

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Terrestrial vertebrates: birds

Encyclopedia of Puget Sound

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Aves

Order

Passeriformes

Family

Emberizidae

Genus

Spizella

NatureServe

Source:
ELEMENT_GLOBAL.2.100732

Classification

Other Global Common Names

Gorrión de Brewer - bruant de Brewer

Informal Taxonomy

Animals, Vertebrates - Birds - Perching Birds

Formal Taxonomy

Animalia - Craniata - Aves - Passeriformes - Emberizidae - Spizella - including the American Tree Sparrow was supported.

Ecology and Life History

Short General Description

Small sparrow, slim with a long, notched tail; 12.5 cm in length. Brown crown with dark streaks, brown cheeks, and a white eye ring. Tan/brown back and rump, with dark streaks on rump, wings brown with wing bars. Undersides dull white with grayish flanks that are sometimes streaked. Juveniles are similar to the adults, but duller in color and streaked undersides.

Migration

true - false - true - Winter from the Southwest through Baja and Central Mexico (Rotenberry et al. 1999); often in large, mixed flocks. Northernmost populations move farthest south; nonmigratory in some areas of the southwestern U.S. (Small 1974, Rotenberry et al. 1999).

Non-migrant

true

Locally Migrant

false

Food Comments

In spring and summer consumes many insects (e.g., alfalfa weevils, aphids, beet leafhoppers, caterpillars, beetles). In fall and winter feeds on seeds. Forages mainly on the ground. Drinks free water when available and will bathe in standing water; but adapted to arid environments and can physiologically adjust to water deprivation, obtaining water from foods (Dawson et al. 1979; Rotenberry et al. 1999). <br><br>May be food-limited in winter, as winter density is positively correlated with summer rainfall, and rainfall increases abundance of seeds available to wintering birds (Dunning and Brown 1982).

Reproduction Comments

Breeding begins in mid-April in south to May or early June in north. Clutch size usually three to four. Nestlings are altricial. Reproductive success correlated with climatic variation and with clutch size; success increasing in wetter years (Rotenberry and Wiens 1989, 1991).

Ecology Comments

Can be abundant in sagebrush habitat and will breed in high densities (Great Basin and Pacific slopes), but densities may vary greatly from year to year (Rotenberry et al. 1999). In southeastern Oregon, reported density averaged 200 individuals per square kilometer, but ranged from 29 to 533 per square kilometer (Rotenberry and Wiens 1980; Wiens and Rotenberry 1981). Dobler et al. (1996) reported densities of 50 to 80 individuals per square kilometer in eastern Washington. In Great Basin, density usually ranged 150-300 per square kilometer, sometimes exceeding 500 per square kilometer (Rotenberry and Wiens 1989). Breeding density 0.08-0.10 individuals per hectare in shadscale habitat in eastern Nevada (Medin 1990). Breeding territory usually averages between 0.6-1.25 hectares and will contract as densities of breeding birds increase (Wiens et al. 1985). Mean territory sizes reported by Rotenberry et al. (1999) varied from 0.1 to 2.36 hectares.

Length

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1999-11-30

Global Status Last Changed

1996-12-04

Other Status

LC - Least concern

Distribution

Conservation Status Map

Global Range

FG - 20,000-2,500,000 square km (about 8000-1,000,000 square miles) - FG - BREEDING: subspecies BREWERI: southern British Columbia, southern Alberta, southwestern Saskatchewan, Montana, and southwestern North Dakota, south to southern California (northern Mojave Desert), southern Nevada, central Arizona, northwestern New Mexico, central Colorado, southwestern Kansas, northwestern Nebraska, and southwestern South Dakota (AOU 1998, Rotenberry et al. 1999). Mapped BBS data show centers of summer abundance in the Great Basin and Wyoming Basin (Sauer et al. 1997). Subspecies TAVERNERI: southwest Alberta, northwest British Columbia, southwest Yukon, and southeast Alaska (Rotenberry et al. 1999). NON-BREEDING: southern California, southern Nevada, western and central Arizona, southern New Mexico, and west Texas, south to southern Baja California, Sonora, and in highlands from Chihuahua, Coahuila, and Nuevo Leon south to northern Jalisco and Guanajuato (Terres 1980, AOU 1998, Rotenberry et al. 1999). Highest wintering abundance in Arizona (21.41 birds per 100 survey hours) 1959-1988 (Sauer et al. 1996).

Global Range Code

Global Range Description

20,000-2,500,000 square km (about 8000-1,000,000 square miles)

ELEMENT_GLOBAL.2.100732