Carbonated Sierra Finch Rhopospina carbonaria Scientific name definitions

The Carbonated Sierra Finch is an endemic species to Argentina. It breeds in shrubby areas of central to northern Patagonia, and some move farther north into the Monte Desert and southern Chaco in the non-breeding season. In some respects it is most similar to the Mourning Sierra Finch (P. fruticeti) although the Carbonated is a smaller and daintier species. Male Carbonated Sierra Finches are blackish-gray, becoming blackish through wear, although solidly black on the face and underparts. Their back begins brownish-gray with blackish streaks, becoming more grayish as they wear. The most attention grabbing feature is the bright yellow bill, a rather long bill with a curved culmen. In many ways it is a smaller and darker version of the Mourning Sierra Finch, although the Carbonated lacks obvious wingbars. Its song is given accompanied by a flight display where male ascends as high as 15 m, and descends in a gliding flight giving a two second long high pitched buzzy trill “tz-tz-tz-tz-tzee-tzee-tzee.”

14·5 cm; 16·1–18 g. A relatively small, long-tailed sierra finch with thick-based, long conical bill. Male has face blackish, crown to back dark cold grey, streaked blackish, becoming washed with brown on un­streaked lower back to rump; upperwing and tail blackish with narrow dark grey edging, two inconspicuous narrow white wingbars; chin to undertail-coverts blackish, more greyish on flanks; in fresh plumage (autumn and into winter) has more extensive brownish coloration above and bolder wingbars; iris dark brown; bill bright yellow; legs dusky pinkish. Differs from similar Rhopospina fruticeti in smaller size, more extensive black below, less noticeable wingbars. Female is brownish-grey and streaked above; paler below, off-white with darker streaking; bill duller than in male. Immature male is similar to female, but with blackish throat to breast, and belly feathers tipped with buff, becoming increasingly blackish on underparts with wear.

C Argentina from Córdoba, Mendoza, San Luis and W & SW Buenos Aires S to C & E Chubut; non-breeding also N to S Salta.

Alvaro began birding as an 11 year old in Canada, and eventually trained in Evolutionary Ecology studying, creatures as varied as leaf-cutter ants and Argentine cowbirds. But his career has been focused on birding tourism, both as a guide and owner of his tour company, as well as a avitourism consultant to various organizations. He is the author of Birds of Chile, New World Blackbirds: The Icterids, as well as the ABA Field Guide to the birds of California. He lives in Half Moon Bay, California where he is known for his pelagic birding trips. Email: alvaro@alvarosadventures.com.