Hemithraupis guira nigrigula

Exhibits pronounced sexual dimorphism and is a small-sized passerine belonging to the Thraupidae family, corresponding to the species Hemithraupis guira, which measures approximately 4.7 to 5.1 inches (12 to 13 centimeters) in total length and weighs between 10 and 14 grams. The adult male displays a striking and contrastingly colorful plumage, characterized by a jet-black to dark olive-brown facial mask and throat, which is sharply delineated by a conspicuous bright yellow superciliary stripe that extends down the sides of the neck. The lower throat is black, transitioning to a warm rufous-orange or ochre-rufous breast patch, while the belly is a soft olive-gray or whitish color, and the rump is a distinctive bright yellow-green. Conversely, the female is far more cryptically colored, displaying an overall olive-green upperpart and a dull yellowish-green underpart, completely lacking the dark facial mask and the bright orange breast of the male, which provides excellent camouflage within the forest foliage.

Geographical distribution: This bird has an extensive range throughout much of South America, being widely distributed across countries such as Colombia, Venezuela, Guyana, Suriname, French Guiana, Ecuador, Peru, Bolivia, Paraguay, northern Argentina, and throughout the vast majority of Brazil, spanning from the Amazon basin to the southern Atlantic forest. It occupies an altitudinal gradient ranging from sea level up to 3,900 feet (1,200 meters), although it can occasionally be recorded at higher elevations in the Andean foothills.

Habitat: It occupies a diverse array of wooded and semi-open ecosystems. It is a characteristic inhabitant of gallery forests, humid forest edges, deciduous woodlands, secondary growth forests, arboreal savannas such as the Brazilian Cerrado, and arid scrub forests like the Caatinga. It also adapts well to disturbed environments, including mature plantations and urban parks with dense tree canopies. It shows a strong ecological preference for the canopy and subcanopy layers of the vegetation, rarely descending to the understory.

Feeding: The diet is omnivorous and highly opportunistic, consisting of a balanced mix of animal prey and plant material. It actively searches for small insects, caterpillars, beetles, spiders, and other arthropods by gleaning them from the underside of leaves and the fine bark of outer twigs. It supplements this protein intake with a variety of small fleshy fruits, berries, and seeds from various shrubs and trees, and it frequently feeds on flower nectar during the dry season when certain canopy trees are in full bloom.

Behavior: It is a highly active, restless, and social species. It is most commonly encountered as an active participant in mixed-species feeding flocks in the forest canopy, frequently moving alongside other tanagers, warblers, and tyrant flycatchers. It displays acrobatic foraging maneuvers, performing quick hops and short, fluttery flights among the outermost foliage. Vocalizations consist of high-pitched contact calls, rendered as a thin tsip, and a rapid, melodic territorial song consisting of high-frequency whistles.

Nesting: The breeding process involves the construction of a delicate, cup-shaped nest built primarily by the female but with the male´s assistance. It is constructed using fine plant fibers, rootlets, dry leaves, and lichen, held together and attached to branches with abundant spider webs for structural flexibility and camouflage. The nest is typically hidden in dense foliage at heights ranging from 6 to 33 feet (2 to 10 meters) above the ground. The female lays a clutch of 2 to 3 whitish or cream-colored eggs, densely speckled with reddish-brown or lavender spots. Incubation is performed almost exclusively by the female, whereas both parents actively participate in feeding and protecting the chicks.

Conservation status: It is currently classified as Least Concern (LC) on the IUCN Red List of Threatened Species. This classification is justified by its extremely large geographical range and a population size that, despite lacking precise census data, is considered stable. However, localized populations of Hemithraupis guira face ongoing threats from habitat loss and fragmentation driven by agricultural expansion and deforestation across its distribution range.