Golden-faced tyrannulet
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Tyrannidae
Genus:	Zimmerius
Species:	Z. chrysops
Binomial name
Zimmerius chrysops (Sclater, PL, 1859)

The golden-faced tyrannulet (Zimmerius chrysops) is a species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Colombia, Ecuador, Peru, and Venezuela.^[1]

The golden-faced tyrannulet was originally described as Tyrannulus chrysops.^[2] Through much of the twentieth century it and several other tyrannulets were kept in genus Tyranniscus but a study published in 1977 erected the present genus Zimmerius for them.^[3][4]

Beyond its transfer to Zimmerius the golden-faced tyrannulet's taxonomy is unsettled. The International Ornithological Committee (IOC) follows a study published in 2013 and treats it as a monotypic species.^[1][5] The South American Classification Committee of the American Ornithological Society, the Clements taxonomy, and BirdLife International's Handbook of the Birds of the World (HBW) add two subspecies that the IOC treats as the two subspecies of Coopmans's tyrannulet (Z. minimus). (Clements does recognize "golden-faced" and "Coopmans's" groups within the species.) The four systems follow a 2008 publication and agree that a previously assigned subspecies is now the Choco tyrannulet (Z. albigularis). They also follow it to agree that former subspecies flavidifrons does not belong to the golden-faced tyrannulet. However, the IOC treats it as the species Loja tyrannulet (Z. flavidirons) and the other three assign it as a subspecies of the Peruvian tyrannulet (Z. viridiflavus).^{[1][3][6][7][8][excessive citations]}

This article follows the monotypic species IOC model.

The golden-faced tyrannulet is 10.5 to 11.5 cm (4.1 to 4.5 in) long and weighs 7.7 to 10.6 g (0.27 to 0.37 oz). The sexes have the same plumage. Adults have a bright yellow forehead, supercilium and area around the eye and a dark stripe through the eye on an otherwise yellowish white face. Their crown, back, and rump are bright olive. Their wings are dusky with bright yellow edges on the coverts and flight feathers. Their tail is dusky. Their throat is yellowish white and their breast, flanks, and belly dull whitish. They have a brown or brownish gray iris, a small, rounded, blackish bill, and gray legs and feet.^{[9][10][11][12][13][excessive citations]}

The golden-faced tyrannulet is found in the Andes of northwestern Venezuela, the Serranía del Perijá on the Venezuela-Colombia border, in all three ranges of the Colombian Andes except in the southwesternmost Nariño Department, and on the eastern Andean slope for the full length of Ecuador and into Peru as far as the Department of San Martín. It inhabits the interior and edges of humid montane forest, secondary woodland, and semi-deciduous forest, and also coffee plantations and gardens. In elevation it ranges up to 2,400 m (7,900 ft) in Venezuela, to 2,300 m (7,500 ft) in Colombia, to 2,200 m (7,200 ft) in Ecuador, and occurs between 1,000 and 2,450 m (3,300 and 8,000 ft) in Peru.^{[9][10][11][12][13][excessive citations]}

The golden-faced tyrannulet is a year-round resident throughout its range.^[9]

The golden-face tyrannulet feeds on insects and small fruits, especially those of mistletoes (Loranthaceae). It forages singly or in pairs. It generally spends about the same amount of foraging time as part of mixed-species feeding flocks as away from them, though it apparently seldom joins them in Colombia. It feeds mostly in the forest canopy, perching horizontally with its tail cocked and actively moving about and gleaning food while perched or with short flights.^{[9][10][11][12][excessive citations]}

The golden-faced tyrannulet apparently has some breeding activity (nest-building, egg-laying and incubation, or provisioning nestlings) during most of the year. The female makes a dome-shaped nest with a side entrance, typically within hanging moss or a bunch of moss on a tree trunk. They usually are between about 5 and 12 m (15 and 40 ft) above the ground but one in eastern Ecuador was 45 m (150 ft) up. The clutch is two eggs that are cream-white with liver-brown spots. The female alone incubates, for about 17 days. Both parents feed the nestlings between hatch and fledging 17 to 19 days later.^[9][10]

The golden-faced tyrannulet is highly vocal.^[9][12] Its dawn song is a "plaintive chu-de-de'e'e".^[10] Another author describes it as "a slightly rising, accelerating, laughing series of notes: tee-heeheeheehee".^[13] Its daytime calls include "a simple clear 'cleeuw' or 'peeur' "^[12] and a "ringing 'teer-tif' "^[9].

The IUCN follows HBW taxonomy and so includes Coopmans's tyrannulet in its assessment of the golden-faced tyrannulet. The golden-faced represents a large majority of the combined taxa's population; the IUCN has assessed the species sensu lato as being of Least Concern.^[14] The golden-faced tyrannulet is considered common in Venezuela and Colombia, "widespread and often common" in Ecuador, and "common and widespread" in Peru.^{[10][11][12][13][excessive citations]} It occurs in several protected areas.^[9]