Greater Rhea vs Lesser Rhea
Rhea americana 比較対象 Rhea pennata
Side-by-Side Comparison
| 属性 | Greater Rhea | Lesser Rhea |
|---|---|---|
| 学名 | Rhea americana | Rhea pennata |
| 目 | Rheiformes | Rheiformes |
| 科 | Rheidae | Rheidae |
| 保全状況 | Near Threatened | Least Concern |
| 体長 | — | — |
| 翼開長 | 120.9 cm (47.6 in) | 125.9 cm (49.6 in) |
| 体重 | 25250.0 g (890.67 oz) | 21925.0 g (773.38 oz) |
| 食性 | Herbivore of South American pampas; eats broad-leafed plants, seeds, fruits, and opportunistically insects and small … | Grazes Andean plateau grasses, shrub leaves, seeds, and cacti; supplements with beetles and small lizards … |
| 一腹卵数 | 20-30 | -- |
| Population Trend | — | — |
Habitat Comparison
Greater Rhea
Open grasslands, pampas, cerrado, and agricultural fields in eastern and central South America. Prefers flat terrain with scattered shrubs. Adapts to cattle ranches and crop fields at low to mid elevations.
Lesser Rhea
Puna grasslands and Andean high-altitude plains at 3,500–5,000 m, Patagonian steppe, and southern South American semi-desert. Tolerates cold wind-exposed conditions. Makes seasonal movements to lower altitudes in winter.
Song & Call Comparison
Greater Rhea
Males produce a deep, resonant booming call. Females emit softer, lower contact calls. Courting males call loudly with a 'naaaaao' booming sound to attract multiple females.
Lesser Rhea
Males produce a similar booming 'naaaaao' call to Greater Rhea but somewhat softer. Females respond with lower contact calls. Vocalizations primarily function in mate attraction.
Geographic Range & Migration
Greater Rhea
Widespread in eastern South American grasslands from northeastern Brazil to Argentina. Resident in the Pampas and Cerrado; does not migrate.
Lesser Rhea
Found in Andean highlands and Patagonian steppes from southern Peru and Bolivia through Argentina to Tierra del Fuego. Year-round resident.
保全状況
Greater Rhea
Lesser Rhea
How to Tell Them Apart
Greater Rhea
Overall gray-brown plumage with loose, shaggy feathers covering the body. Black collar at base of neck in males. Females are paler. Underparts whitish; bare gray neck and head.
Lesser Rhea
Brown-gray body feathers with conspicuous white spots on wing coverts and back. Neck pale and thinly feathered. Underparts whitish. Paler overall than Greater Rhea with distinctive spotted pattern.
About These Birds
Greater Rhea
South America's largest bird, standing up to 1.5 m tall with fluffy grey-brown plumage and long, powerful legs. Flightless, fast-running, and omnivorous—eating plants, insects, and small vertebrates. Found across open grasslands, pampas, and cerrado from Brazil to Argentina. Males incubate eggs and raise chicks alone.
Lesser Rhea
Smaller than the Greater Rhea, with pale grey-brown plumage speckled with white spots on wings and back. Flightless, gregarious, and fast-running. Feeds on broad-leaved plants, roots, and small animals. Males are polyandrous, building communal nests and tending multiple broods simultaneously.