Half-collared Sparrow Arremon semitorquatus

Boldly-patterned sparrow found in the understory of humid forest and second growth; usually difficult to see. Note the bicolored bill (black above and bright yellow below) and black patches on either side of the breast. The black head contrasts with a narrow white eyebrow and gray nape. Olive-green above and largely white below with gray flanks. Listen for a high-pitched “tzee–tzeuuu-tzeeuuu” and a metallic “tic.”