range and live under conditions that are not unlike those of our own western plains a 

 century ago. Much of the pampas is now given over to cattle-raising, for which the 

 unfenced prairies are ideally suited. Their production of beef has become an impor- 

 tant factor in world economy. 



As might be expected in so distinct an area, the pampas support a generous fauna 

 very different from that of the adjacent forests and mountains. Bird life is varied and 

 abundant, but several families and many genera and species are endemic to these 

 grasslands. Perhaps the most characteristic of all is the rhea, the so-called South 

 American ostrich. True ostriches have never existed in the western hemisphere, but the 

 somewhat smaller rhea is similar in habits and appearance. Like ostriches, rheas can 

 not fly, and live in open country where keen vision and speed afoot are adequate pro- 

 tection. Adult birds, when frightened, have been clocked at more than forty miles per 

 hour and few horses can outrun them in a flat race. Rheas are the largest of all Ameri- 

 can birds and may weigh up to 85 pounds. They are especially abundant on the 

 campo of Matto Grosso, in southwestern Brazil, the locale of the Museum's exhibit 

 being Capao Bonito. 



The breeding habits of this species are rather unusual. Rheas normally associate in 

 mixed flocks that may number several dozen birds. At the beginning of the nesting 

 season, in October or November — springtime south of the equator — each mature male 

 gathers together a few females. A nest of grass, twigs, and feathers is prepared and used 

 by each small flock. As many as 65 eggs may be deposited in a single nest by the several 

 females, although 25 or fewer are more usual numbers. 



Rhea eggs are whitish or buffy in color, and have a volume eqiial to that of about a 

 dozen hen's eggs. Although somewhat strong in taste, the eggs are often eaten by the 

 natives. Incubation varies from four to six weeks and is accomplished by the male 

 alone, although the females remain in the general vicinity of the nest during the period 

 of incubation. Later they are joined by the male and chicks. It is these family groups, 

 together with the young birds of the previous year, that constitute the large mixed 

 groups to be found between breeding seasons. Rheas are principally herbivorous but 

 probably also eat lizards, snakes, and large insects. 



Another endemic bird of the pampas is the cariama, a specimen of which is pic- 

 tured in the right background of the rhea exhibit. This long-legged bird stands about 

 three feet tall and is believed to be the closest living relative of Mesemhriornis, a power- 

 ful carnivorous bird that became extinct several million years ago. Cariamas have no 

 close living relatives, but they are usually classified between the rails and the bustards. 

 They are largely terrestrial in habit, although capable of flight, and feed principally 

 on reptiles and insects. Four large eggs are deposited in a bulky nest of sticks and twigs 

 usually placed in the upper branches of a small tree. 



Several hundred less noteworthy birds also inhabit the South American pampas. 

 Some, like the burrowing owl in the center background of the exhibit, are represented 

 in similar areas of North America by close relatives. Others, like the tinamou, a par- 

 tridge-like bird of tropical America, are replaced in forest areas elsewhere by distinct 

 species. Various hawks, flycatchers, finches and many others with a high percentage of 

 endemism occur in such abundance as to constitute a fauna that is characteristic of the 

 South American grasslands. 



[811 



