Russet-backed Oropendola

The Russet-backed Oropendola is a large member of the blackbird family found across lowland and foothill forest and forest edge habitats of South America. Like other oropendolas, it is a highly social species, nesting in colonies where dozens of long, hanging woven nests dangle from a single tree.

Males perform an elaborate bowing display accompanied by a distinctive gurgling, liquid song, one of the more memorable vocal performances among Neotropical songbirds, often given from perches near the nesting colony.

• Body is olive-brown overall, with the back and rump showing a warmer chestnut-russet tone that gives the species its name
• Head is olive-brown, without strong facial markings
• Bill is pale, often yellowish or horn-colored, contrasting with the darker plumage
• Tail is long and graduated, with the central feathers dark and the outer feathers bright yellow, conspicuous in flight and during display
• Wings are olive-brown, unmarked, built for sustained flight between colony and foraging areas
• Distinguished from other oropendola species by the specific combination of russet back tone and yellow (rather than more variably colored) outer tail feathers

Adults of both sexes show similar olive-brown plumage with a russet back and yellow outer tail feathers, though males are considerably larger than females, a marked size dimorphism typical of oropendolas. Juveniles are duller overall, with less contrast between the back and body color, gradually acquiring the adult pattern with maturity. There is no strong seasonal plumage variation in adults.

This species is found in lowland and foothill tropical forest, forest edges, and cultivated land with scattered tall trees across much of South America, particularly the western Amazon basin and adjacent regions. It is largely resident, with colonies often returning to the same nesting trees across multiple seasons.

Russet-backed Oropendolas feed on fruit and insects, foraging in the canopy and sometimes in more open habitats near forest edges. They nest colonially, weaving long, sock-like hanging nests from plant fibers, often dozens to a single tree, with males displaying and mating with multiple females within the colony. The species is known for its loud, bubbling, gurgling song, often delivered with an exaggerated bowing motion by displaying males.