Yellow-rumped Serin

Fairly small tanager-like sparrow with an extremely tiny range in the foothills of eastern Panama, from around 800–1,200 m. Distinctive in range: olive-brownish overall with brighter yellow-ochre underparts, darker blackish face, and staring pale eye. Like other chlorospingus, typically found in small groups, often with a mixed-species flock. Usually sticks to the understory or middle levels of humid forest.

Very small endemic songbird with tiny bill and disproportionately large head. Gray above and below, with rich rufous wings, tail, and lower flanks, white throat stippled in brown, and yellow eye. The throat may appear puffy white (without stippling), depending on the bird's posture. Inhabits shrubbery, brushy areas, and bamboo stands in higher montane forests. Gives simple, high-pitched, two-note calls.

A small ground-hugging bird found in areas with dense cover, usually near moving water. Unlike most shortwings, male and female are not significantly different; both sexes are brown or gray overall, with a white eyebrow and throat. Furtive and quite difficult to see; its tinkling melodic song, which starts with 1-2 slow notes and quickly accelerates into a rushed-sounding loud musical jumble, may give away its position in the undergrowth.