Yungas Guan (Penelope bridgesi)

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Image of a Yungas Guan in its natural habitat
Birds Guan

Introduction

The Yungas Guan (Penelope bridgesi) is a large guan in the family Cracidae. It occurs on the eastern Andean slopes of southern Bolivia and north-western Argentina, particularly in the Southern Yungas and adjoining woodland. Once treated as a subspecies of the Dusky-legged Guan (Penelope obscura), it is recognised as a separate species by the IOC World Bird List. Its biology remains less well documented than that of many widespread guans.

Physical Description

The Yungas Guan is approximately 68–75 cm long. It has a dark head, chestnut-brown to brown upperparts with greenish reflections, and relatively broad pale margins on the wing coverts. The underparts are generally more uniform and slightly paler than the back, while the tail is dark brown.

The face has areas of bare grey skin, the throat is reddish, the bill is dark and the legs are dark grey. Available descriptions do not establish marked sexual dimorphism. The species is noticeably larger and differs in plumage from the Dusky-legged Guan, with which it was formerly grouped.

Range and Habitat

The Yungas Guan is endemic to the eastern slopes and foothills of the Andes in southern Bolivia and north-western Argentina. In Bolivia, its range includes parts of Cochabamba, Santa Cruz, Chuquisaca and Tarija. In Argentina, it has been recorded in Jujuy, Salta, Tucumán and Catamarca.

It inhabits subtropical and tropical forest, including Yungas woodland, humid valleys, foothill forest, dry to semi-humid woodland and some secondary forest and forest edges. It may also occur in wooded areas bordering the Chaco, although its principal habitat is associated with the Andean foothills and Yungas vegetation rather than open dry Chaco.

A study in the Southern Yungas of Argentina found that habitat use increased near rivers and streams. The species is resident rather than migratory, although local movements may occur in response to food availability and seasonal conditions.

Behaviour and Diet

The Yungas Guan uses both trees and the ground and is often observed alone, in pairs or in small groups. It is most active around dawn and dusk. Its call has been described as a powerful, harsh series of notes that can carry through forested valleys.

Males perform a territorial or courtship flight display accompanied by loud, rattling wingbeats, particularly around dawn. This behaviour is useful for detecting the species before it is seen.

The available species accounts describe the Yungas Guan as feeding in both trees and on the ground. Its diet is considered primarily plant-based and includes fruits and other vegetation, although detailed field studies of its feeding ecology are limited. Guans can disperse seeds, so the species may contribute to forest regeneration within its range.

Breeding information is also limited. Available Argentine records describe a platform nest made from sticks and stems, lined with leaves, with a clutch of approximately three white eggs. Further study is needed to confirm the full breeding season, incubation period and parental care of the species.

Identification Tips

  • Look for a large, dark guan with a blackish head, brown or chestnut body and greenish reflections in the plumage.
  • Broad pale margins on the wing coverts can be conspicuous at close range.
  • The grey bare facial skin, reddish throat and dark legs help separate it from some other guans.
  • Listen for a harsh, repeated call or for the hollow rattle of a displaying bird’s wings at dawn.
  • In the Yungas region, compare it carefully with the Red-faced Guan (Penelope dabbenei) and Andean Guan (Penelope montagnii) where their ranges or habitats approach one another. The Yungas Guan is distinguished by its darker head and brown body pattern, while the Red-faced Guan has a much more obviously red face.
  • The Dusky-legged Guan (Penelope obscura) is the closest taxonomic comparison, but it is geographically separated from P. bridgesi across much of the species’ range and differs in size and plumage.

Conservation Status

The Yungas Guan should not be described simply as Near Threatened without qualification. It is recognised as a separate species only relatively recently, and a separate current IUCN Red List category was not identified in the sources reviewed. Argentina’s national 2017 assessment listed the taxon as Vulnerable.

The principal concerns are loss and fragmentation of forest, agricultural expansion, logging, infrastructure development and hunting. Habitat conversion is especially important in foothill areas, while hunting pressure may affect local populations because guans are relatively large and conspicuous birds.

Important conservation measures include protecting remaining Yungas and foothill forest, maintaining connected habitat along rivers and wooded valleys, improving enforcement against illegal hunting and supporting local monitoring. Research on population size, distribution in Bolivia, breeding success and responses to habitat change is still needed.

Frequently Asked Questions

Where does the Yungas Guan live?

It occurs in southern Bolivia and north-western Argentina, mainly in Yungas forest, Andean foothills, humid valleys and adjoining dry to semi-humid woodland.

Is the Yungas Guan a separate species?

Yes. It was formerly treated as the subspecies Penelope obscura bridgesi, but morphological evidence and subsequent taxonomic decisions support recognition of Penelope bridgesi as a separate species.

How large is a Yungas Guan?

Adults are approximately 68–75 cm long. Reliable information on average body mass is not well established in the sources used for this account.

What does the Yungas Guan eat?

It feeds both in trees and on the ground and is considered primarily plant-eating, taking fruits and other vegetation. Detailed studies of its diet are limited.

Is the Yungas Guan endangered?

Its separate global IUCN category remains unclear in the sources reviewed. Argentina’s 2017 national assessment classified it as Vulnerable, and habitat loss, fragmentation and hunting are recognised conservation concerns.

How can the Yungas Guan be identified in the field?

Search forest edges, wooded valleys and foothills around dawn. Its large size, dark head, brown body, pale wing-cover margins, harsh call and rattling-wing display are useful identification features.

References

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