Darwin’s Rhea has a scientific name Rhea pennata, and is also known as Lesser Rhea. This bird is a large flightless one, but happens to be the smaller of two extant species of rheas. It is predominantly found in the Altiplano and Patagonia in South America. It has a height of 90–100 cm (35–39 in) and a weight range of 15-25 kg (33–55 lb). Owing to the possession of large wings, it is able to run particularly well. In fact, its wings are lager than those of other ratites. It can even reach speeds of 60 km/h, and this really helps it to outrun predators. It possesses sharp claws on its toes, and these are very effective weapons. Furthermore, it has plumage that is spotted white and brown, with the upper part of their tarsus being feathered.
These birds love to live in areas of open scrub in the grasslands of Patagonia and on the Andean plateau (the Altiplano), through the countries of Argentina, Bolivia, Chile, and Peru. They are known locally by a variety of names, and this depends on the location. Examples of such local names include suri, choique, ñandú petiso, or ñandú del norte. Interestingly, all subspecies prefer grasslands, brushlands and marshland. It has, however, been realised that the nominate subspecies prefers elevations less than 1,500 m (4,900 ft), where the other subspecies typically range from 3,000–4,500 m (9,800–14,800 ft), but locally down to 1,500 m (4,900 ft) in the south.
The males handle incubation, and in the process become aggressive. Owing to their aggressiveness, the females have no other option than to lay the latter eggs near the nest rather than inside it. Though most of the eggs are moved into the nest by the male, some remain outside where they rot and attract flies. Interestingly, the male, and later the chicks, feed on these flies. Usually, the incubation period is 30-44 days, and the clutch size falls within the range of 5-55 eggs.