Moss-backed Sparrow

Arremon dorbignii

Boldly-patterned sparrow found in montane forests from Bolivia to northwestern Argentina. Usually in pairs on or near the ground, foraging at the edge of forest. Note the bicolored bill with an orange-yellow lower mandible. Also look for the bold black-and-white head pattern, black chest band, and bright mossy-green back. The song is a series of high-pitched notes.

Identification

The adult male moss-backed sparrow's head is mostly black, with a white supercilium from the lores to the back of the head and a narrow gray streak on the crown. The neck is gray and the back, wings, and tail are dull olive green. Its underside is white with grayish edges and a narrow black band across the upper chest. The adult female is similar but duller overall. The crown strip is olive and the underparts are buffy with brown flanks. Juveniles are similar to the adults but duller. The moss-backed sparrow shares the "striking orange bill" of its former "parent" saffron-billed sparrow. Six specimens from Argentina had a mean weight of 22.1 g (0.78 oz)

Taxonomy

The moss-backed sparrow was formerly considered a subspecies of saffron-billed sparrow (Arremon flavirostris). In January 2021, both the South American Classification Committee (SACC) of the American Ornithological Society (AOS) and the International Ornithological Congress (IOC) elevated it to species status.

Scientific name
Arremon dorbignii
Authority
Sclater, PL, 1856
Order
Passeriformes
Family
Passerellidae
Genus
Arremon

Range and habitat

The moss-backed sparrow is found in Bolivia from La Paz, Cochabamba, and Santa Cruz Departments into northwest Argentina as far south as Catamarca Province.<p>The moss-backed sparrow is primarily inhabits tropical deciduous forest, both primary and second-growth. It is also often found near forest edges, interior openings, and along waterways. In elevation it ranges from sea level to 1,400 m (4,600 ft).

Migration
Resident species

Behavior

Though the moss-backed sparrow's diet is not well known, it does include fruit, grain, and insects.<p>The moss-backed sparrow nests from October into December. Its nest is enclosed and is built up to 1 m (3.3 ft) above ground. The mean clutch size is 2.8 eggs and the female does all the incubation. Both sexes feed nestilings.

Conservation

Population trend
stable

Photos

Distribution

Bird Calls

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