native to South America
and are related to the
ostrich and emu. The greater rhea (Rhea
americana) is found in open
country from northeastern Brazil southward to Argentina, while Darwin's rhea (Pterocnemia
pennata) lives from Peru southward to Patagonia, at the tip of the
continent. Both species are considerably smaller than the ostrich; the common
rhea stands about
tall and weighs about
distinguished from ostriches by their three-toed feet (those of the ostrich
have two), their lack of fine plumes, and their brownish colour. The birds
frequent open, treeless country and evade predators by running. They are
omnivorous and can utilize a wide variety of plant and animal foods. Rheas do
not form lasting pairs, and males incubate the eggs and raise the young.
Moreover, the birds are polygamous, i.e., the male broods the eggs of
several females laid in one nest. The females lay up to 50 eggs, about 13 cm (5 inches) long, in a
shallow, grass-lined nest dug by a male in the ground. He then incubates the
eggs, and the chicks hatch in about 6 weeks and are herded about by the male
for another 6 weeks thereafter. Rheas frequently associate with deer or
guanacos, forming mixed herds like those of ostriches.
rhea (2011). Encyclopædia Britannica Ultimate Reference Suite.
: Encyclopædia Britannica.