Original description: Junco bairdi Ridgway 1883
Taxonomic history in AOU/AOS Check-list
AOU 1 (1886): Baird’s Junco, Junco bairdi
AOU 2 (1895): Baird’s Junco, Junco bairdi
AOU 3 (1910): Baird’s Junco, Junco bairdi
AOU 4 (1931): Baird’s Junco, Junco bairdi
AOU 5 (1957): Baird’s Junco, Junco bairdi
AOU 6 (1983): Yellow-eyed Junco, Junco phaeonotus [bairdi group, Baird’s Junco]
AOU 7 (1998): Yellow-eyed Junco, Junco phaeonotus [bairdi group, Baird’s Junco]
IUCN Conservation Status: Near threatened
Behavior: The juncos are among our most trusting sparrows, this species no exception. When Marston Abbott Frazar visited Baja California in 1886, Baird Juncos “often came into a shed where Mr. Frazar prepared his specimens, and hopped about his feet, under the table.” They also stole bits of dried venison, an appetite paralleling the Dark-eyed Junco’s taste for suet at wintertime bird feeders. Baird Juncos are more retiring in the face of human disturbance when they are nesting, in May, June, and July.
Most feeding takes place on or near the ground beneath pines or oaks or on the edges of forest clearings. Males sing from concealed perches at low to mid-level in trees.
Voice: The song of the Baird Junco is characterized by great variety, with a wide range of syllable and phrase types and shorter, less frequent trills than in the Yellow-eyed Junco; the high number of unique syllables and the low number of repeated syllables is diagnostic of this species. The song has been compared to that of a House Wren, a Passerina bunting, or a Rufous-crowned Sparrow. A light, cheerful melody without pronounced cadence, the song creates an impression of blithe aimlessness, high and low notes mixed into a relaxed twittering warble. When a trill is included, it tends to be high-pitched, wiry, and short, unlike the more rolling, lower-pitched trills that make up the Dark-eyed Junco’s song.
The common call is a low-pitched and harsh chak, often doubled or given in a rapid accelerating series that ends in rasping notes somewhat recalling those of a Canyon Towhee. There is also a very short, high-pitched tseet, insect-like and often faint, closely resembling the corresponding note of mainland Yellow-eyed Juncos.
Detailed description and measurements drawn from standard reference works
Adult: Inner three pairs of tail feathers slaty blackish. Rectrix 4 usually mostly or entirely blackish on both webs, especially in females; rectrix 5 variably mixed black and white on both webs, the outer web sometimes all black or all white. Rectrix 6 mostly or entirely white on outer web, variably pure white or mixed black and white on inner web. Upper tail coverts and rump buffy brown. Back and scapulars cinnamon brown. Wing short. Primaries and secondaries blackish with narrow gray or dull cinnamon edges. Tertials broadly edged cinnamon brown on outer web. Greater and median coverts cinnamon brown; brown of coverts flows into brown of scapulars. Wing coverts without whitish tips. Nape soft bluish gray with faint cinnamon brown wash.
Under tail coverts, vent, and center of belly grayish off-white, flowing into pale gray of upper breast and throat. Flanks dusky pinkish buff, sides of lower breast brighter pinkish buff. Breast and throat very pale gray or grayish white.
Crown and sides of head soft slaty gray, distinctly set off from brown of back but flowing smoothly into paler gray throat. Lore blackish.
Tarsus and long flesh-pink. Eye staring yellow. Bill rather long and sharply pointed; lower mandible and base and edges of upper mandible yellowish pink, remainder of upper mandible dark gray.
Juvenile: Inner three pairs of tail feathers slaty blackish. White on outer tail usually restricted to rectrices 6 and 5. Upper tail coverts and rump dull brown with fine scattered streaks. Back and scapulars dull cinnamon brown with fine darker shaft streaks. Primaries and secondaries slaty with narrow grayer or browner edges. Tertials slaty with broad brown edges. Greater and median coverts broadly edged dusty brown on outer webs; brown of coverts flows into brown of scapulars. Nape buffy gray with narrow streaks, only indistinctly contrasting with brown back.
Under tail coverts dull white. Vent and center of belly off-white with scant fine streaking; flanks and sides of lower breast light buffy with dusky streaking. Breast pale buffy gray with coarse dusky streaking. Throat dull white with dusky flecks and streaks.
Crown buffy grayish with dusky streaks. Ear coverts and neck sides dull brownish gray with fine, faint streaks.
Tarsi and toes light pinkish brown. Eye dull pale brownish yellow. Bill deep at base and long; lower mandible light brown at base and dusky at tip, upper mandible darker.
Length 133-148 mm (5.2-5.8 inches)
Wing chord 67-72 mm (2.6-2.8 inches)
Tail 61-66 mm (2.4-2.6 inches)
Mass 18 g