Darwin's Rhea(Rhea pennata)
They are also known as the Lesser Rhea. They stand at 90-100 cm tall. Length is 92-100 cm and weight is 15-28.6 kg. Like most ratites, it has a small head and a small bill, the latter measuring 6.2-9.2 cm, but has long legs and a long neck. It has relatively larger wings than other ratites, enabling it to run particularly well. It can reach speeds of 37 mph, enabling it to outrun predators.
The sharp claws on the toes are effective weapons. Their feathers are similar to those of ostriches, in that they have no aftershaft. Their plumage is spotted brown and white, and the upper part of their tarsus is feathered. The tarsus is 28-32 cm long and has 18 horizontal plates on the front.
Three subspecies have traditionally been recognized:
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R. p. garleppi is found in the puna of southeastern Peru, southwestern Bolivia, and northwestern Argentina.
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R. p. tarapacensis is found in the puna of northern Chile from the region of Arica and Parinacota to Antofagasta.
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R. p. pennata is found in the Patagonian steppes of Argentina and Chile.
Habitat
Darwin's rhea lives 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. All subspecies prefer grasslands, brushlands and marshland. However, the nominate subspecies prefers elevations less than 1,500 m, where the other subspecies typically range from 3,000 to 4,500 m, but locally down to 1,220 m in the south.
Diet
The lesser rhea is mainly a herbivore, with the odd small animal (lizards, beetles, grasshoppers) eaten on occasion. It predominately eats saltbush and fruits from cacti, as well as grasses.
Breeding
At the onset of the rhea’s mating season, males battle over territories. Once obtaining a nesting site, they begin attracting females by swiftly running toward them with wings outstretched. After gathering between 2 and 12 females, the male encircles them in a courtship display, calling out and flapping his wings as he runs. He breeds with the female group and takes them to a nest, where they consecutively lay their eggs. The female group then departs, returning every few days to lay more eggs. Once all the eggs are deposited, ranging in number from 13 to 30, the females leave once again. They head off to breed with another male and make ready to lay eggs in another nest. The male is left to incubate and raise his hatchlings alone. He incubates the eggs for 35 to 40 days, fiercely wary of any animal that approaches, including females coming to lay more eggs. In response to this aggressiveness, the females will often lay their eggs nearby, rather than directly in the nest. After the first chick hatches, it starts to cry out, which encourages the others to hatch. In a span of 24 to 28 hours, all the hatchlings appear, downy gray-brown with black stripes. The male leads the chicks into the brush after a few days’ time, and they communicate with one another through whistles. If a chick is frightened or too cold or hot, it shelters in the safety of its father’s wings. The highly protective male will often adopt lost chicks, leading to substantial age differences within the group. Fathers care for their chicks for six months, but young may stay in a group up until they reach sexual maturity at 2 or 3 years old. The lesser rhea survives an average of 20 years in the wild but can live up to 40 in captivity.
Population
According to the IUCN Red list, they are classed as Least Concern(LC). The global population size has not been quantified, but this species is described as uncommon. The species is suspected to have undergone declines owing to the effects of hunting and egg-collection, with overgrazing perhaps being less significant but still having a negative impact.
Threats
The Darwin’s rhea is hunted for its eggs, feathers and meat. Other threats include habitat destruction for agriculture and, in some areas, it is hunted for sport. Its skin is made into rugs, and body parts are used in traditional medicine.
Conservation
Conservation Actions Underway
CITES Appendix II.
Conservation Actions Proposed
Develop campaigns to raise awareness and reduce hunting, egg-collecting and the domestication of wild immature birds. Prevent illegal hunting and egg-collecting, while developing alternative sustainable harvesting programmes. Harvest orphan eggs (eggs sporadically laid outside nests) for use in captive breeding and reintroduction programmes. Maintain "mallín" (meadow) habitats in adequate condition as nesting sites.