Lesser Rhea

The Lesser Rhea, also known as Darwin's Rhea, is a large, flightless, ostrich-like bird of open southern South American landscapes, smaller and generally paler than its relative the Greater Rhea. Its plumage is a grayish-brown, mottled with white spotting, particularly on the back and wings, which helps it blend into the dry grasslands and scrub it inhabits. It has a long neck, long powerful legs built for running, and small, largely vestigial wings that it spreads for balance and display rather than flight.

Well adapted to some of the harshest and most open habitats in South America, from the windswept steppe of Patagonia to the high, cold altiplano of the central Andes, it relies on speed and keen eyesight to evade predators, capable of running at high speed across open terrain when threatened.

Key field marks

• Large, flightless, ostrich-like body shape with a long neck and long legs
• Grayish-brown plumage mottled with white spotting, paler overall than the Greater Rhea
• Small, vestigial wings held for balance rather than flight
• Found in open steppe and altiplano habitat, generally at higher elevations or further south than the Greater Rhea

Similar species

• Greater Rhea is larger and darker, generally found in lower-elevation grasslands and savanna further north and east, with limited range overlap.
• No other bird in its range shares its large flightless body and open-country habitat.

Habitat

Inhabits open grassland steppe, scrubland, and high-altitude altiplano.

Range

Found across Patagonia in southern Argentina and Chile, as well as the high Andean altiplano of Peru, Bolivia, and northern Chile and Argentina.

Migration

Generally sedentary, though some populations may shift locally with seasonal food and water availability.

Behavior

Gregarious outside the breeding season, often forming loose flocks that forage together; males are polygynous, mating with several females who lay eggs together in a single shared ground nest that the male alone incubates and defends.

Voice

Generally silent, though males give a low, booming call during the breeding season, along with hissing sounds when alarmed or threatened.

Feeding

Feeds on a broad diet of grasses, seeds, roots, insects, and small vertebrates, foraging by walking slowly across open ground.

Nesting

Males build a simple ground scrape nest and incubate the combined clutch from several females, sometimes twenty or more eggs, alone, later caring for the chicks after hatching.