Taxonomy and biogeography of the Monte Yellow-Finch (Sicalis mendozae): understanding the endemic avifauna of Argentina?s Monte Desert.

ARETA JI; PEARMAN M; ÁBALOS R

THE CONDOR

COOPER ORNITHOLOGICAL SOC

Año: 2012 vol. 114 p. 654 - 671

0010-5422

The poorly known Pseudochloris mendozae Sharpe, 1888, has usually been considered a subspecies of the widespread Greenish Yellow-Finch (Sicalis olivascens)of the Andes of Peru, Bolivia, northern Chile, and northwest Argentina. In this work, we present data on morphology, vocalizations, ecology, and distribution supporting the recognition of the Monte Yellow-Finch (Sicalis mendozae) (Sharpe 1888) as a full species. S. mendozae is 10% smaller in size (with no overlap in wing or bill measurements), and its average weight is 80% that of S. olivascens. In comparison with S. olivascens, breeding males of S. mendozae are considerably brighter, lack any olive tinge on the throat and breast, lack any dorsal mottling or streaking, and have a brighter olive rump. In fresh plumage nonbreeding males are similar to four other Sicalis species, differing subtly. Female S. mendozae is closest in appearance to the allopatric Patagonian Yellow-Finch (S. lebruni), differing chiefly by its olive rump. The song, complex song, and calls of S. mendozae are diagnostic, though it also imitates some other birds. S. mendozae is endemic to the arid Monte Desert of western Argentina from western Tucumán south to Mendoza, and is parapatric with S. olivascens of high Andean steppes. Contrary to literature reports, S. mendozae is nonmigratory but may move altitudinally, descending to lower altitudes during winter. We propose the recognition of the Monte Desert as a new Endemic Bird Area, based on the overlap of the geographic ranges of several bird species.