Sooty-capped Chlorospingus
Chlorospingus pileatus
eBird describes the Sooty-capped Chlorospingus like this: Small, plump, tanager-like sparrow, dull olive above with blackish cheek and crown, whitish throat, and obvious white eyebrow. Thick bill. Sexes alike. Overall very similar to Common Chlorospingus, but that species has only a white spot behind the eye, not a long eyebrow. Usually found at higher elevations than Common Chlorospingus, but some overlap. Occurs in forest and edge habitats. Look for small noisy groups moving through the understory, often with mixed-species flocks.
The Birds of the World website introduces the Sooty-capped Chlorospingus with this descriptive information: A well-marked bush-tanager, this species is endemic to Costa Rica and western Panama, where it is typically found in small groups of up to 20, which often consort with warblers and other small birds moving through the undergrowth or midstory. It inhabits mossy forests at elevations between 1600 and 2100 m, and sometimes ventures into cleared areas. The head is black with a long but somewhat ragged-looking, white supercilium that starts above the eye, contrasting with the olive upperparts and gray-white throat; the rest of the underparts are largely yellow, becoming whiter over the median line. Compared to other bush-tanagers, the black head and white supercilium are highly distinctive, and the Sooty-capped Bush-Tanager is perhaps more likely to be confused, albeit briefly, with the Black-cheeked Warbler (Basileuterus melanogenys); the latter has a chestnut crown and much paler underparts.
I met my first Sooty-capped Chlorospingus on the late morning of February 9, 2023 as our small group of birders was headed to higher elevations traveling toward Cerro Del Muerte, Costa Rica. Although the bird was deep in the shadows I was able to get a photo that had enough detail to identify the bird and and it to my life list.