Chestnut-headed Oropendola

The Chestnut-headed Oropendola is a medium-sized member of the blackbird family (Icteridae), best known for its glossy black body plumage set off by a rich chestnut-brown head, and a pale, bluish-tipped bill. Males are notably larger than females, a common pattern in oropendolas driven by strong sexual selection within colonies.

The tail shows the typical oropendola pattern of black central feathers and bright yellow outer feathers, most visible in flight or when the bird calls. Its overall shape is fairly long and slim compared to many blackbirds, with a long, pointed bill suited to a varied fruit-and-insect diet.

This species is highly social and colonial, nesting in loose to dense colonies where dozens of long, woven, sock-like nests hang from the outer branches of tall emergent trees, often a dramatic and conspicuous feature of forest edges within its range.

Key field marks

• Chestnut-brown head contrasting with glossy black body
• Pale, bluish-tipped bill
• Black tail with bright yellow outer feathers
• Colonial nester with distinctive long, hanging woven nests

Similar species

Russet-backed Oropendola and Russet-backed Oropendola differ in overall color, with the Chestnut-headed being most easily identified by the sharply defined chestnut head against a black body; Montezuma Oropendola is much larger with an entirely different, more extensively pale bill and bicolored body pattern.

Habitat

Chestnut-headed Oropendolas inhabit humid forest, forest edge, and plantations, often nesting in isolated tall trees near forest edges or clearings.

Range

The species ranges from Honduras and Nicaragua through Costa Rica and Panama into Colombia and Ecuador, occupying lowland and foothill regions on both slopes in Central America.

Migration

It is largely a non-migratory resident, with colonies often returning to the same nesting trees over multiple years.

Behavior

This oropendola is highly social, nesting and foraging in colonies, and males perform an elaborate bowing display accompanied by a gurgling call to attract females and defend status within the colony hierarchy.

Voice

The voice includes a distinctive liquid, gurgling, bubbling song given during the male's bowing display, along with various chattering and clucking calls.

Feeding

It feeds on fruit, insects, and nectar, foraging in the canopy and sometimes in mixed flocks with other oropendolas or caciques.

Nesting and breeding

Colonies build numerous long, pendulous, woven nests that hang like socks from the tips of outer branches in tall emergent trees, an adaptation thought to deter predators and parasitic botflies; the species is also a frequent host to parasitic cowbirds.