Yellow-billed Jacamar (Galbula albirostris) in the Yasuni

The Yellow-billed Jacamar is a relatively small member of the genus Galbula found north of the Amazon River in northern Amazonia from eastern Ecuador, southern Colombia and northwestern Brazil. It is replaced south of the Amazon by the very similar Blue-cheeked Jacamar (Galbula cyanicollis). The Yellow-billed Jacamar prefers the understory of terra firme forest. It is quite a striking jacamar, having bright iridescent green upperparts, and rich chestnut underparts, including the undersurface of the tail. Sexes differ slightly, with males having a white throat. It gets its name from the entirely yellow lower mandible. The Yellow-billed Jacamar is most similar to Blue-cheeked Jacamar, which has more iridescent "blue" cheeks, an entirely yellow bill, and males lack the white throat. They are not known to overlap, apparently separated by the Amazon River. Yellow-billed does overlap with the Purplish Jacamar (Galbula chalcothorax), which lacks the chestnut, and prefers the mid-story of both varzea and "transitional" forest. It is also sympatric with White-chinned Jacamar (Galbula tombacea), which favors dense vegetation along the edges of slow-moving streams and oxbow lakes, is larger, and has chestnut restricted to the lower belly. Like other jacamars, the Yellow-billed Jacamar forages by sallying out from low branches for flying insects.