It is found in the Altiplano and Patagonia in South America. The incubation period is 29–43 days. In its native range, it is known as ñandú (Spanish) or ema (Portuguese). [7] He identified specimens from Sergipe, and Rio Grande do Norte, Brazil, in 1758.
the sarsaparilla Smilax brasiliensis) have also been recorded as foodplants. The rheas are flightless birds of the genus Rhea, native to South America. Möhring's reason for choosing this name is not known. Taxonomy. [8][28], Like many birds which feed on tough plant matter, the greater rhea swallows pebbles which help grind down the food for easy digestion. Male greater rheas are very territorial during the breeding season. These birds survived the winter and succeeded in breeding in habitat similar to that of their South American one. Although the shared shape of the breastbone of ratites is considered by many authorities to be more a product of adaptationto living on the ground rather than shared ancestry, others assume shared ancestry and place the ratites together. However, modern genetic analysis conflicts with this. eval(ez_write_tag([[250,250],'newworldencyclopedia_org-large-mobile-banner-2','ezslot_3',169,'0','0']));eval(ez_write_tag([[250,250],'newworldencyclopedia_org-large-mobile-banner-2','ezslot_4',169,'0','1'])); Some eggs are left outside the nest. [33], The greater rhea is considered a Near Threatened species according to the IUCN, and they have a decreasing range of about 6,540,000 square kilometres (2,530,000 sq mi). When in flocks, they tend to be less vigilant, but the males can get aggressive towards other males. He will gradually relax and allow her to crouch and lay the egg at the edge of the nest. The IUCN lists the puna rhea as a separate species.

The male incubates from ten to eighty eggs. The nest is a simple shallow and wide scrape in a hidden location; males will drag sticks, grass, and leaves in the area surrounding the nest so it resembles a firebreak as wide as their neck can reach. Darwin's rhea (Rhea pennata), also known as the lesser rhea, is the smaller of the two extant species of rheas. The populations of Argentina and Uruguay are most seriously affected by the decline, in the former country mostly due to the adverse impact of agriculture, in the latter mostly due to overhunting in the late 20th century. [3] The nests are thus collectively used by several females and can contain as many as 80 eggs laid by a dozen females; each individual female's clutch numbers some 5–10 eggs. [8], The adults have an average weight of 20–27 kg (44–60 lb) and often measure 127 to 140 cm (50 to 55 in) long from beak to tail; they usually stand about 1.5 m (4 ft 11 in) tall, with a typical range of 1.4 to 1.7 m (4 ft 7 in to 5 ft 7 in), to the top of the head. Rheas. This ratite is the largest bird in the Americas. He continued searching fruitlessly for this bird. [3] The nest is kept in a hidden location; males will drag sticks, grass, and leaves in the area surrounding the nest so it resembles a firebreak as wide as their neck can reach. They also store urine separately in an expansion of the cloaca.[2]. Rheas are large birds with gray-brown plumage, long legs, and long necks. (South American Classification Committee). In October 2008, the population was estimated by two German scientists at around 100 birds. The male will roll the egg into his nest. As late as 2008 it was classified in the monotypic genus Pterocnemia. In mixed cerrado and agricultural land in Minas Gerais (Brazil), R. a. americana was noted to be particularly fond of beetles. These birds can reach 5.6 feet (1.7 meters) in height, and weigh up to 88 pounds (40 kilograms). After doing this and attracting females, they will continue calling at a specific female, and will start to either walk alongside her or in front of her while spreading his wings and lowering his head. In its new home, the greater rhea is considered generally beneficial as its browsing helps maintain the habitat diversity of the sparsely-populated grasslands bordering the Schaalsee biosphere reserve.[34]. [21], Captive-bred greater rheas exhibit significant ecological naïvete. [2], 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. Rheas. [4] The species is believed to be declining due to increased hunting[1] and the conversion of central South American grasslands to farmland and ranchland. [3] They are from the family Rheidae, and the order Rheiformes. eval(ez_write_tag([[728,90],'newworldencyclopedia_org-medrectangle-4','ezslot_2',162,'0','0'])); Rheas are members of a group of birds known was ratites. "Phylogenetic evidence for multiple losses of flight in Ratite birds", "A phylogenomic study of birds reveals their evolutionary history", https://simple.wikipedia.org/w/index.php?title=Rhea_(bird)&oldid=6175772, Pages with citations using unsupported parameters, Creative Commons Attribution/Share-Alike License. Proposal (#348) to South American Classification Committee: Incluir, Classification of birds of South America, Part 01: Proposal #348, https://www.newworldencyclopedia.org/p/index.php?title=Rhea_(bird)&oldid=989331, Creative Commons Attribution/Share-Alike License. Schetini de Azevedo, C., and R. J. [8][28], They do not usually eat cereal grains, or monocots in general. [4] In 2008, the [[American Ornithologists' Union (SACC) subsumed Pterocnemia into the genus Rhea. It is much attracted to sparkling objects and sometimes accidentally swallows metallic or glossy objects. The genus name Rhea was given in 1752 by Paul Möhring and adopted as the English common name. They also store urine separately in an expansion of the cloaca. Even though they cannot fly with them, they still have a wingspan approximately 8 ft. across. However, the leaves of particular grass species like Brachiaria brizantha can be eaten in large quantities, and Liliaceae (e.g.

These flightless birds use their long, powerful legs to outrun trouble. Greater rheas have a fluffy, tattered-looking plumage. Darwin's very bad day: 'Oops, we just ate it!. A current approach is to combine them as different families within the order Struthioniformes, with rheas in the family Rheidae, ostriches in the family Struthionidae, and emus in the family Casuariidae. As their names might suggest, Greater Rheas are larger than their “Lesser” counterparts. Magnoliidae fruit, for example of Duguetia furfuracea (Annonaceae) or avocados (Persea americana, Lauraceae) can be seasonally important. [3][10] Despite the delineation of this species as the "greater rhea" versus the lesser rhea, some data on body masses indicates that both species average about 23 kg (51 lb) in weight, but even at mass parity that greater species appears larger and is taller due to its longer legs and neck, whereas the lesser rhea is more compact and more so resembles an outsized, long-necked turkey in build.

It is because of the absence of breast bone which is connected with flying muscles in flying birds. [8] However, the average clutch size is 26 eggs laid by 7 different females.[3]. The greater rhea is native to Argentina, Bolivia, Brazil, Paraguay, and Uruguay. Rheas eat mostly plants, fruits, seeds, and nuts, but also will also eat insects and other small animals (like lizards).[1].
The greater rhea (Rhea americana) is a species of flightless bird native to eastern South America. Recent evidence suggests that dominant males may enlist a subordinate male to roost for him while he starts a second nest with a second harem. Jaramillo, A., P. Burke, and D. Beadle. Rheas congregate in flocks of 20 to 30 birds. On the following day Darwin shot a guanaco (a camelid), which provided them with a Christmas meal. The greater or American rhea (also called the 'Nandu') is a large, flightless bird from forests of South America. The adults have an average weight of 20–27 kg (44–60 lb) and 129 cm (51 in) long from beak to tail; they usually stand about 1.50 m (5 ft) tall. Even in the wild—particularly in Argentina—leucistic individuals (with white body plumage and blue eyes) as well as albinos occur. R. a. araneipes (Brodkorb, 1938)[2] Davies S.J.J.F. However, an alternative classification places the rheas in the order Rheiformes, the emus in the order Casuariiformes, and the ostriches remaining in Struthioniformes. In its new home, the greater rhea is considered generally beneficial as its browsing helps maintain the habitat diversity of the sparsely populated grasslands bordering the Schaalsee biosphere reserve.[22]. The greater rhea (Rhea americana) is also known as the gray, common or American rhea. Most of the eggs are moved into the nest by the male, but some remain outside. In mixed cerrado and agricultural land in Minas Gerais (Brazil), R. a. americana was noted to be particularly fond of beetles. Feral dogs are known to kill younger birds, and the Southern caracara (Caracara plancus) is suspected to prey on hatchlings. Their weight ranges from 30 lbs. A rhea's tarsus has horizontal plates on the front of it. Moreover, the birds' health is affected by wholesale pesticide and herbicide spraying; while not threatening on a large scale, locally the species may be seriously affected by poisoning. It can reach speeds of 60 km/h (37 mph), enabling it to outrun predators. Greater rheas are half-grown about three months after hatching, and sexually mature by their 14th month. As with his other collections, these were sent it to John Stevens Henslow in Cambridge.

Pages 46-49 in J. Forshaw (ed.

[8][28], In fields and plantations of plants they do not like to eat, e.g., cereals or eucalyptus, the greater rhea can be a species quite beneficial to farmers. 2008. It is not clear whether this applies to the species in general, but, for example, in pampas habitat, beetle consumption is probably lower simply due to availability while Orthoptera might be more important.