Yellow-margined Flatbill

Overview

The yellow-margined flatbill, also known as Zimmer's flatbill, is a species of tyrant flycatcher found across most mainland South American countries except Argentina, Chile, Paraguay, and Uruguay. It is currently assessed by the IUCN as being of Least Concern, although its population is believed to be decreasing.

Identification

• Length of 13 to 13.5 cm with a mass of 12 to 17.5 g and a wide, flat bill featuring a black maxilla and pale brownish to horn mandible.
• Plumage generally consists of an olive-tinged gray head, olive-green back and rump, and pale olive breast and flanks, with the nominate subspecies displaying a pale yellow belly.
• Wings are dusky with yellow edges on the greater coverts and remiges, creating a pale speculum and faint wing bar when closed, accompanied by a thin white broken eye-ring in adults.
• Vocalisations vary geographically, including nasal and buzzy notes in the Guianas and Venezuela, and whistled, rising or rising-falling series in Ecuador and Peru.

Habitat

Found in mature humid forests including terra firme, várzea, secondary forest, and plantations, as well as on the slopes of tepuis where Venezuela, Guyana, and Brazil meet. Typically located in the forest mid-story to subcanopy but can occur lower at edges, ranging in elevation from sea level to over 1,000 m in Brazil and up to 1,300 m in Peru.

Diet

Primarily feeds on arthropods and occasionally small fruits, foraging singly or in pairs and frequently joining mixed-species feeding flocks. It typically captures prey using short upward sallies from a perch to grab or hover-glean items from leaves, though less often catches prey in mid-air.

Did you know?

The species has a complicated taxonomic history, having been treated as a subspecies of the yellow-olive flatbill until about 1940, and for a time the yellow-winged flatbill was confusingly called the yellow-margined flatbill.