Wikipedia Source Page

Summary

The orange-billed sparrow (Arremon aurantiirostris) is a species of bird in the family Passerellidae, the New World sparrows. It is found from Mexico to Peru.

Taxonomy and systematics

The orange-billed sparrow was formally described in 1847 with its current binomial Arremon aurantiirostris.

The orange-billed sparrow has these eight subspecies:

A. a. saturatus Cherrie, 1891 A. a. rufidorsalis Cassin, 1865 A. a. aurantiirostris Lafresnaye, 1847 A. a. strictocollaris Todd, 1922 A. a. occidentalis Hellmayr, 1911 A. a. santarosae Chapman, 1925 A. a. erythrorhynchus Sclater, PL, 1855 A. a. spectabilis Sclater, PL, 1855

Description

The orange-billed sparrow is 14.5 to 16.5 cm (5.7 to 6.5 in) long and weighs about 35 g (1.2 oz). The sexes have the same plumage and all subspecies have the eponymous bright orange bill. Adults of the nominate subspecies A. a. aurantiirostris have a black crown with a gray stripe along its middle and a wide white supercilium on an otherwise black face. Their upperparts are olive-green and their wings and tail a darker olive-green with yellow at the bend of the wing. Their chin has a small black area and their throat is white with a wide black band below it across the upper upper breast. Their flanks and undertail coverts are brownish gray to olive-green and the rest of their underparts grayish white. They have a very dark brown iris and light brown legs and feet. Juveniles have sooty olive upperparts and breast with a slightly paler olive supercilium and throat. Their belly is dingy buffy olive and their flanks and undertail coverts are darker and browner.

The other subspecies of the orange-billed sparrow are similar to the nominate but differ from it and each other thus:

A. a. saturatus: wider supercilium begins near nostrils, somewhat darker green upperparts, wider breast band, and darker dusky wash on sides and flanks A. a. rufidorsalis: wider supercilium begins near nostrils and somewhat darker green upperparts A. a....