Whilst there are several species of Rhea, this writeup will concern itself mainly with the Common Rhea: Rhea Americana. The other species of rhea are largely similar, but specifics of size and distribution for example are different. Nonetheless, all are large, flightless and South American.

The common rhea is a large, flightless bird. Taxonomically they are cousins to the ostrich, and share many characteristics with them. The common rhea, while larger than the other rheas is still somewhat smaller than an ostrich, usually reaching a height of only four or five feet. A typical rhea has a weight in the region of 60 or 70 lbs.

Rheas have a body shape very similar to that of the ostrich, but their plumage is a dirty grey colour. They use their wings more than many other flightless birds, using them to balance while running at speeds of up to 40 miles per hour. Their heavily muscled legs are also capable of dealing a very powerful kick. Rheas have hard spurs on their feet, and can bring about a force of 800 psi. Although not quite as dangerous as a cassowary rheas can seriously injure people.

Rheas live in small herds, and often react very agressivly to intrusion. At some times of the year males leave the herds and live on their own. Rheas naturally occur in areas of grassland and scrub in Argentina, but some have been introduced into North America by people who want to farm them. This is difficult, as rheas are very stubborn and violent. In their native habitat they eat a wide range of things, such as leaves, grubs and berries, but when hungry are pretty omnivorous.

After the large creamy eggs are layed by the female following mating they are incubated and guarded by the male. During this time, which may last more than a month he is especially agressive, and will charge almost anything that approaches closely, including other rheas.

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Struthioniformes
Family: Rheidae
Genus Rhea

University of Michigan