Bird of the Month: Black-chinned Sparrow

audubon-logo-wood-duck-square-medium-300x300By Maxine Tinney

On a warm summer afternoon, an adult male Black-chinned Sparrow appears at one of the groundwater pans to quench its thirst with a refreshing drink of cool, clear water. Normally this sparrow is inconspicuous with retiring habits; now it bravely emerges from the chaparral of tangled shrubs and thorny bushes. This male Black-chinned Sparrow (Spizella atrogularis) is a breeding adult songbird and has a black chin patch, throat, and lores, highlighted by a grey torso saddled with reddish brown back and brown wings, light gray underparts, long brownish tail, and a thick, bright orangy-pink bill. The male arrives in Prescott during the spring breeding season and sometime sings for a mate from conspicuous perches, but otherwise tends to seek discreet cover in dense shrubs. Both sexes may be located by voice and song with a series of slurred notes, ssip/ssip/ssip, running together and accelerating into a rapid trill.

Black-chinned Sparrow at The Ranch at Prescott. Photo by Maxine Tinney.

In the nearby underbrush, a female with feathers of more restricted greys and brownish tones answers the male’s song, chooses him as a mate, and builds a shallow, open cup nest near the ground in dense shrub. The nest is made of dry grass, weed stems, and yucca fibers, and lined with fine grass, plant fibers, sometimes feathers or animal hair. The “mate-guarding” male stays close to the female during the laying of two to four pale blue eggs, sometimes unmarked and sometimes dotted with dark brown. Incubation is about 13 days, and mostly performed by the female. Both parents bring food to the hatchlings. Juveniles have paler crowns and underparts lightly streaked with a brownish wash.

While breeding, Black-chinned Sparrows mainly eat adult and larval insects from inner foliage and ground, while extracting seeds from grasses, foraging various forbs including pinyon, and even snacking on seeds from hanging seed blocks.

Four subspecies — each based on variation in size and plumage coloration — are currently recognized by birders and ornithologists. Subspecies character divergence is likely a response to differences in climate and migratory behavior across the western range of the species. As fall and winter near, the Black-chinned Sparrows render migration to lower elevations and lower latitudes, often to Mexico.

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Visit Prescott Audubon Society at PrescottAudubon.Org. Contact them at Contact@PrescottAudubon.Org.

After retiring as an overseas educator of mathematics, science, and computer in International Schools for some 30 years, Maxine Tinney enjoys traveling, hiking, biking, birding, photography, and the environs of central Arizona.

 

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