Rusty-margined Guan

Identification

The rusty-margined guan is a medium-sized game bird measuring 55 to 73 cm in length, with weight varying by subspecies from 750 to 1,150 grams. Its most distinctive feature is the rusty-red margining on its wing coverts and scapulars—the characteristic that gives the species its name. The bird's upperparts are dark olive to brownish, while the belly displays the same rusty coloration as the wing edges. A pale face with a prominent supercilium (eyebrow stripe) is another key identifying mark, though the supercilium's color varies among subspecies, ranging from white to buff or ochre. Subspecific differences in plumage are notable: P. s. jacupemba appears paler overall, while P. s. major is notably darker than the nominate subspecies.

Range & Habitat

The rusty-margined guan is found across a wide geographic range spanning Argentina, Bolivia, Brazil, and Paraguay, with four recognized subspecies occupying different portions of this distribution. The nominate subspecies inhabits Amazonian Brazil south of the Amazon River, while P. s. jacupemba ranges from central and southern Brazil into eastern Bolivia. P. s. major occupies extreme southeastern Brazil, eastern Paraguay, and extreme northeastern Argentina.

This adaptable species inhabits diverse lowland landscapes throughout its range, including interior and edge habitats of heavy forest, gallery forest, restinga, woodlands in cerrado grasslands, caatinga scrub, mangroves, and even Eucalyptus plantations. Although primarily a lowland bird, it can be found at elevations up to 1,300 meters in parts of Brazil, demonstrating considerable habitat flexibility.

Behaviour & Diet

The rusty-margined guan is essentially sedentary, though in some areas it makes modest daily movements of up to 400 meters between roosting sites in higher areas and lowland feeding grounds. The species is a reluctant flier, seldom flying more than about 20 meters and typically much less. It forages alone, in pairs, or in small groups of up to ten birds, typically feeding between 5 and 10 meters above ground, though it also frequents the forest floor.

The bird's diet is almost entirely frugivorous, with one study identifying fruit from 117 different plant species in its diet. It supplements this primarily fruit-based diet with small amounts of flowers, leaves, and insects. During breeding season—October to February in Argentina and August to February in southeastern Brazil—pairs establish territories and construct stick platforms lined with leaves in trees, typically laying clutches of three eggs. The species produces a distinctive gruff barking call, probably associated with alarm, and performs a wing-whirring display whose function remains poorly understood.

Best Time & Places to See It

The rusty-margined guan is reasonably common only within protected areas, making national parks and reserves the most reliable locations for viewing. The breeding season from August to February is an excellent time to locate birds, as they are more vocal and active during this period. Early morning hours typically offer the best opportunities for observation, when birds are most active in their feeding areas.

Photography Tips

The guan's habit of feeding in the mid-canopy at heights of 5 to 10 meters makes a telephoto lens essential for photography. Its dark plumage and preference for forested habitats present low-light challenges; a fast lens or high ISO setting will help capture detail. The rusty margins on the wings and the distinctive pale supercilium are key field marks worth highlighting in images. Patient observation near fruiting trees during early morning is likely to yield the best photographic opportunities, as birds concentrate in food-rich areas.