Greater Rhea

The greater rhea, known scientifically as Rhea americana, is a flightless bird of impressive stature, native to the open landscapes of eastern South America. This grand avian, the largest bird native to the Americas, tips the scales at a hefty 20–27 kilograms and stands with a regal posture, reaching heights of 1.4 to 1.7 meters. Its plumage is a study in dishevelment, a mix of gray and brown feathers that cloak its body in a seemingly untidy fashion.

Identification Tips

To identify the greater rhea, look for a bird with a relatively small head and bill, the latter measuring a modest 8–10.4 centimeters. Its legs are long and robust, adorned with 22 horizontal plates on the front of the tarsus. The absence of a hind toe and the presence of three forward-facing toes are notable. The wings, though not used for flight, are lengthy and assist in balance and courtship displays.

Habitat

The greater rhea favors a variety of open areas, including grasslands, savannas, and grassy wetlands. It thrives in regions where tall vegetation offers some respite, yet it avoids the dense tropical forests and high-altitude regions above 1,200 meters.

Distribution

This species is indigenous to Argentina, Bolivia, Brazil, Paraguay, and Uruguay. Remarkably, a feral population has established itself in Northern Germany, adapting to a habitat similar to its South American range.

Behaviour

Greater rheas are generally silent, save for the low booming noises emitted by males during mating season and the mournful whistle of the chicks. They exhibit flocking behavior outside of the breeding season, forming groups of up to 100 individuals. When threatened, they may flee in a zigzag pattern, using their wings for balance.

Song & Calls

The greater rhea's vocal repertoire is limited, with males producing a low booming sound during the breeding season and chicks emitting a whistle.

Breeding

The breeding season sees males becoming territorial and performing elaborate courtship displays to attract females. After mating, females lay their eggs in the male's nest, with clutches from multiple females resulting in nests containing up to 80 eggs. The male takes sole responsibility for incubation and chick rearing, with the incubation period lasting 29–43 days.

Similar Species

The lesser rhea (Rhea pennata) is similar in appearance but can be distinguished by its smaller size and more compact build, resembling an oversized, long-necked turkey.

Diet and Feeding

Greater rheas are omnivorous, with a diet consisting of broad-leaved foliage, seeds, fruits, insects, scorpions, fish, small rodents, reptiles, and small birds. They are known to consume pebbles to aid in digestion and occasionally ingest metallic objects due to their attraction to shiny items.

Conservation status

The IUCN lists the greater rhea as Near Threatened, with a decreasing population due to habitat loss and hunting. Conservation efforts are in place to manage international trade and protect the species in its non-native German range.