Rhea

Rhea, also called Nandu and American Ostrich, a genus of South American birds, which form, according to the most recent researches, a somewhat isolated group, though nearer to the ostriches than to any other birds. They are incapable of flight, but the wings are rather better developed than in any other of the so-called 'Struthious' birds; they present an interesting archaic character in the persistence of a claw upon each of the three digits, thus recalling very forcibly the origin of the wing from a prehensile forelimb. As in the ostrich and the apteryx, the feathers have no after-shaft, and the colour of the eggs is white. The male bird incubates. There are three distinct species—viz. R. americana, R. macrorhyncha, and R. Darwini, which are to be distinguished by their geographical range as well as by external and internal differences of structure. The first-named species inhabits the southern half of the continent. R. macrorhyncha, which is darker coloured, especially on the head, is found in north-east Brazil. R. Darwini, in which most of the feathers have white tips, is found in south-eastern South America. They all prefer grassy plains (campos), herd in troops, and run with great rapidity.