Lee Richardson Zoo

Common Rhea

A.K.A. Greater Rhea

Order:  Rheiformes

Family:  Rheidae

Scientific Name:  Rhea americana 


DescriptionThe common rhea is the largest New World (Americas) bird.  It is flightless, but smaller and more slender than an ostrich, reaching only 4-5 feet tall and weighing up to 50 pounds.  Its bill is wide and flat.  The feathers are gray, loose and plume-like covering the body, head and neck.  They lack tail plumes.  The soft plumes are ineffective for flight but provide good insulation.    The body is egg-shaped, with a long, flexible and sparsely feathered neck.  The legs are long and bare of plumage with three toes per foot.  Males are slightly taller than females, with black plumage around the lower part of the neck.


Home Range:  South American regions of southern Peru,
central Brazil and Argentina.


Habitat:  Grasslands and open brush country, pampas.


Reproduction:  In the southern hemisphere, the breeding season is September to December.  In the northern hemisphere it is during the spring and summer.  Males become very territorial during breeding season.  The cock builds a nest consisting of a simple depression in ground, sometimes lining it with a few plants or grass.  Several females will lay eggs in one nest and the male will incubate the 5-inch long, cream-colored eggs.  Each hen will lay 10-15 eggs and usually about 20-25 eggs are in clutch; up to 80 have been found in one nest.  Incubation lasts from 35-40 days.  The young are 8-10 inches tall at hatching, and are yellow and gray with longitudinal stripes on the back.  They are cared for entirely by the male, and reach adult size in 6 months and sexual maturity in 2-3 years.


Diet in WildMainly grass and leaves, but may also eat some insects, other invertebrates like worms and small vertebrates like lizards and snakes.


Diet in Zoo:  Ratite and rabbit pellets.


General InfoThe rhea has good senses of hearing and sight, allowing them to detect predators from far away.  The ability to run with strides of almost five feet, and dodge and turn suddenly by using their wings like rudders, enables them to escape enemies.  They require very little water other than what they take in with their food.  They have been hunted for both food and sport.  Until recently their feathers have been used for feather dusters.  Rheas are now raised on farms.  In South America, rheas graze alongside sheep, with whom they do compete for food.  However, they are tolerated because they eat the burr type seeds that tangle the wool of the sheep.  Although the rhea, ostrich and emu seem similar, they are not related.  They have developed features to help them survive in similar habitats and all belong to different families.


Conservation Status:  This species is declining, but is still relatively common and widespread.  Causes for the decline include hunting for meat and skins, and conversion of habitat to agricultural land.  They are listed on CITES Appendix ll and IUCN Red List as Near Threatened.


PredatorsJaguars, maned wolves.



Handbook of the Birds of the World,  Vol I. J. del Hoyo; A. Elliot; J. Sargatal.  Lynx Edicions. Barcelona. 1992. pp. 98-103.


Grzimek’s Animal Life Encyclopedia. Vol. 7. Dr. H.C.Bernhard Grzimek. Van Nostrand Reinhold Co. New York. 1975. pp. 88-89.