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THE WORLD'S BIRDS. 



and are so on some Argentine estancias, by driving 

 in and plucking the birds. Clipping would, of 

 course, be better. The flesh is good eating, some- 

 thing between mutton and turkey, and the gizzards 

 have been used for the preparation of pepsin. 



Captivity. — Rheas do well in captivity, both in hot 

 and temperate climates. They breed regularly in 

 European parks. 



Distribution and Species. — South America only, in 

 open grassy country. There are only two species, 

 the Common Rhea {Rhea americana), larger, with 

 grey plumage, black on the crown and at the base 

 of the neck, which lays creamy-white eggs ; and 

 Darwin's Rhea {Rhea darwinii), smaller, brown, 

 spotted with white, and laying pale green eggs. 

 This is confined to Patagonia. Both species are 

 locally known as ostriches. 



Rollers {CoraciidcB). 



Diagnosis. — Tree birds of medium size, with crow-like 

 hills and feet with four free toes, the hind-toe 

 smallest. 



Form. — Bill medium, strong, crow-like, corner of 

 mouth below eye ; feet with shanks medium or 

 short, toes four, all free, hind-toe smallest ; wings 

 short to long ; tail medium to long ; head large, 

 body light. 



Plumage and Colouration. — Feathers close and 

 beautifully coloured, blue, purple, green and 

 lilac being common tints. No sexual difference, 

 as a rule, nor seasonal change, but young are not 

 always like parents. 



Young. — Naked and helpless, fed by parents. 



Eggs. — Several ; pure white. 



Incubation. — About three weeks 



