Slender-billed Oriole

Very finely-speckled dark-grayish duck with a dark eye and an obvious peaked crown. Beak is strongly curved like a ski-jump. Breeding males have a red base to their bill. Upper-wing is dark, while under-wing is paler gray. When perched, distinguish from Hardhead (which have a pale belly patch). Generally uncommon; found beside inland waterholes and ponds. More reliable inland, but can be common one year and absent the next from any given location.

A small, brownish upland cisticola. Remarkably plain: brown on the upperparts and buff below. The unmarked face often has a gentle expression. Found locally in both thorn savanna and broadleaf woodland. Very similar in appearance to Siffling Cisticola, but generally has warmer coloration and lacks streaking on the back. Also similar to Foxy Cisticola, but less rufous, and there is minimal overlap in range. Similar to Dorst’s Cisticola, but smaller, and the cap and back are roughly the same color. Rufous Cisticola’s unimpressive song consists of 2-3 high-pitched, squeaky notes in a descending pattern, very similar to the song of Siffling Cisticola. 

Spectacular but reclusive bird, most often located by its distinctive voice. In N end of range (to NW Bolivia) lives in thick grassy hillsides and Polylepis forest in the high Andes. S of Bolivia, in W Paraguay to central Argentina, expands into Chaco forest in lowlands, where it prefers thorn forest with dense understory. Song an evenly pitched series of metallic or dry notes. Population in central Argentina differs vocally, with a much faster song.