Russet Sparrow - Description

Description

The Russet Sparrow is a small chunky bird, with plumage warm rufous in overall colour. It is a medium-sized sparrow at 14–15 cm (5.5–5.9 in) and 18 to 22.5 grams (0.63–0.79 oz). It has a thick bill suited to eating seeds, which is black on the breeding male, horn-coloured on the non-breeding male, and yellowish with a dark tip on the female. Wingspans for males range between 6.8–8.2 cm (2.7–3.2 in) and those for females from 6.7–7.7 cm (2.6–3.0 in). Tail, bill, and tarsus lengths are 4.3–5.1 cm (1.7–2.0 in), 1.1–1.3 cm (0.43–0.51 in), and 1.6–1.8 cm (0.63–0.71 in), respectively. Measurements for the Russet Sparrow vary geographically, between the three subspecies, and also within the Himalayan subspecies cinnamomeus. The subspecies cinnamomeus is generally larger than the others, and within this form there is a tendency for birds at higher altitudes to be larger, and a clinal variation in size with the smallest birds in the west of the range and the largest in the east. The iris is chestnut in colour. The legs of both sexes are pale brown to pinkish-brown. The flight of all sparrows is swift, and that of the Russet Sparrow is described as swifter and more direct than that of the Eurasian Tree Sparrow.

The sexes differ, or are dimorphic, in their plumage, and have a similar pattern to that in the corresponding sex of House Sparrow. There is some variation between the three subspecies, especially in the colouration of the underparts. Birds of the subspecies rutilans are off-white on their cheeks and the sides of their necks, and have pale grey underparts. Birds of the subspecies intensior have a pale yellow wash on their underparts and cheeks, as well as darker upperparts, while those of the subspecies cinnamomeus have a heavy yellow tinge to their underparts. Moult is poorly recorded, the only records coming from Sakhalin and Himachal Pradesh. In Sakhalin, moult occurs in August and September, between the breeding season and migration. In Himachal Pradesh, aviculturalist G. A. Perreau observed captive and wild birds and reported that they were yellow from December to spring and whitish during the remainder of the year, a pattern which may be atypical.

The breeding male is bright russet or cinnamon red on its upperparts from its crown to its rump, with a black streaking on its mantle. It has a small black bib and black around its eye, separated from the russet of its crown by a very thin white supercilium, a stripe running from the bill to the rear of the head. The side of its neck and cheek are off-white, and its underparts are pale grey or washed with yellow, varying geographically. Shoulders and greater coverts are chestnut, and its median coverts are black at the base with white at the tips. The rest of the wing is light brown with black tinges. Its tail is blackish brown, edged with ashy brown. The non-breeding male differs little from the breeding male, being paler with more orange upperparts. The only species with which the male is easily confused is the Eurasian Tree Sparrow, which differs in its black cheek spot and brown back. The female has mostly pale brown upperparts, and pale grey underparts, so it resembles the female House Sparrow. It differs from the House Sparrow in its slightly darker, russet-tinged plumage. It has a conspicuous cream supercilium from above its eye nearly around its head, and a bold dark brown stripe through its eye. It has mostly greyish brown wings and a back streaked with black and buff. The juvenile is similar to the female, though more pale and sandy. As the male reaches its first winter, it resembles the adult, differing in less bold chestnut and a dusky bib.