Original description: Spizella Breweri Cassin 1856
Taxonomic history in AOU/AOS Check-list
AOU 1 (1886): Brewer’s Sparrow, Spizella breweri
AOU 2 (1895): Brewer’s Sparrow, Spizella breweri
AOU 3 (1910): Brewer’s Sparrow, Spizella breweri
AOU 4 (1931): Brewer’s Sparrow, Spizella breweri breweri
AOU 5 (1957): Brewer’s Sparrow, Spizella breweri breweri
AOU 6 (1983): Brewer’s Sparrow, Spizella breweri
AOU 7 (1998): Brewer’s Sparrow, Spizella breweri [breweri group]
IUCN Conservation Status: Of least concern
Behavior: Brewer Sparrows are gregarious nearly year-round, holding territories only during the breeding season. They are not particularly shy, but if disturbed by humans, they often fly up from the ground to perch atop a low bush and call nervously; adults are known to react to other predator species by “actively and aggressively pursu[ing] weasels, chipmunks, and ground squirrels in [the] vicinity of nests.” Pressed too hard by the human observer, they flee in low, darting flight, perching in the middle distance before dropping again to the ground to feed.
Most feeding takes place in the shallow leaf litter beneath sagebrush and other short woody vegetation, but Brewer Sparrows also clamber about like small finches in low twigs and foliage, methodically taking invertebrates from beneath leaves and at the tips of branches.
Males sing from the tops of bushes, fence posts, and other elevated perches. The tail is held down, the head up, with the bill opened wide.
Voice: The usual call of the Brewer Sparrow, given perched or in flight, is a short, hesitant dsip, with strong attack and very little audible decay. A “soft twittering” is said to be given by females.
The song of this species is one of the great natural phenomena of the American west, heard on the breeding grounds and in migration and winter. Robert Ridgway first heard it on the sage flats of California:
“The song of Brewer’s Sparrow… for sprightliness and vivacity is not excelled by any other of the North American Fringillidae, being inferior only to that of the [Lark Sparrow] in power and richness, and even excelling it in variety and compass. Its song, while possessing all the plaintiveness of tone so characteristic of the eastern Field Sparrow, unites to this quality a vivacity and variety fully equalling that of the finest Canary.”
Like the Timberline, the Brewer Sparrow has two song “types,” a short song comprising one to three different trills and a long song made up of five to ten different trills and syllables. The long song of the Brewer Sparrow is a lon series of sustained tremolos of different tonal quality and at different pitches; unlike the Timberline, many of the phrases are distinctly buzzy and low-pitched, some of them recalling the slow flatulent buzzes of the Clay-colored Sparrow, others similar to the bubbling trills of the Chipping Sparrow. Each tremolo in a single song is different; at least some Timberline Sparrows repeat segments within the long song. The only component of the Brewer Sparrow’s long song to be repeated is “a series of descending sweet notes.”
The short song of the Brewer Sparrow draws on a lexicon of more than 50 discrete trill types. This song typically combines a fast, high-pitched trill with a following slow, lower-pitched trill.
Detailed description and measurements drawn from standard reference works
Adult: Tail feathers dark grayish brown with paler edges. Upper tail coverts and rump pale brownish gray with faint or no darker streaking. Back and scapulars pale brownish gray with blackish streaks. Primaries dark grayish with narrow paler gray edges and tips, secondaries dark grayish with buffy gray edges and tips. Tertials dark grayish, duskier on outer web, with fairly broad pale brown edges and tips. Greater coverts with blackish centers, broad pale brown edges and tips; median coverts with dark gray centers, extending along shaft as narrow points into broad pale buffy tips. Covert tips form two buffy brown wing bars. Marginal coverts of under wing white. Nape brownish to grayish with uniformly scattered moderately fine black streaks not gathered into obvious stripes.
Under tail coverts, vent, belly, breast, and throat dull whitish; breast and flanks slightly grayer or buffier. Throat separated from dull whitish gray jaw stripe by faint narrow brownish lateral throat stripe. Ear coverts bordered below by evenly narrow dark whisker and above behind eye by narrow dark eye line.
Crown pale brown, sometimes with grayer median stripe; narrowly streaked with black, the streaks continuing over the nape and meeting the stripes of the back. Ear coverts pale brownish, bordered above by faint dark eye line and below by faint dark whisker, even throughout its length. Diffuse gray-brown supercilium, less contrasting than jaw stripe. Lore and front of supercilium gray-brown. Clear narrow white eye ring complete or just barely interrupted at back of eye by dark eye line.
Tarsus and toes gray-pink. Small bill pale dull brown to pinkish brown with darker tip and culmen; upper mandible may be noticeably darker than lower.
Juvenile: Tail feathers dark grayish brown with paler edges. Upper tail coverts and rump pale brownish gray with fine darker streaking or spotting. Back and scapulars pale brownish buff with irregular blackish streaks. Primaries dark grayish with narrow paler gray edges and tips, secondaries dark grayish with buffy gray edges and tips. Tertials dark grayish, duskier on outer web, with fairly broad pale brown edges and tips. Greater coverts with dusky centers, broad pale buffy edges and tips; median coverts with dark gray centers and broad pale buffy tips. Covert tips form two broad buffy wing bars. Marginal coverts of under wing white. Nape brownish to grayish with uniformly scattered moderately fine black streaks not gathered into obvious stripes.
Under tail coverts, vent, belly, breast, and throat dull buffy whitish; breast and flanks slightly darker, marked with distinct fine dark brown streaks. Throat separated from dull whitish buffy jaw stripe by faint narrow brownish lateral throat stripe. Buffy ear coverts bordered below by evenly narrow dark whisker and above behind eye by narrow dark eye line.
Crown dull buffy brown, finely streaked with dark brown, the streaks continuing over the nape and meeting the stripes of the back. Ear coverts pale brownish, bordered above by faint dark eye line and below by faint dark whisker, even throughout its length. Diffuse and inconspicuous supercilium, even less contrasting than jaw stripe. Lore and front of supercilium buffy gray-brown. Clear narrow white eye ring complete or just barely interrupted at back of eye.
Tarsus and toes gray-pink. Small bill pale brown with darker tip and culmen.
Length 117-130 mm (4.6-5.1 inches)
Wing 56-66 mm (2.2-2.6 inches)
Tail 57-62 mm (2.2-2.4 inches)
W:T 1.03
Mass 12-14 g
