730 CARACARA TOLYBORUS. 



The rhea is easily tamed, and is constantly seen about tlie 

 huts of the Patagonians. 



In the southern part of Patagonia another species, much 

 smaller, exists, — the Avestris petise, now called Struthio 

 Darwinii, in compliment to the naturalist who has described 

 it. He states that not more than fifteen eggs are found in 

 the nest of the petise, deposited by two or more females.. 

 This bird does not expand its wings when first starting at full 

 speed, after the manner of the northern kind. It is a smaller 

 and more graceful bird : its white feathers are tipped witlh 

 black at the extremities, and the black ones in like manner are 

 tipped with white. 



A third species, the large-billed rhea (Pthea macrorhyncha ), 

 has been discovered. These birds in vast numbers inhabit the 

 wide-extended plains, and afford a welcome addition to the 

 food of their roving inhabitants. 



CARACARA POLYBORUS. 

 The largest caracara — Polyborus Braziliensis — ranges tlie 

 grassy savannahs of La Plata. Across the desert, between 

 the rivers Negro and Colorado, numbers constantly attend the 

 line of road, to devour the carcasses of the exhausted animals 

 which chance to perish from fatigue and thirst. It also at- 

 tends the es-tancias and slaughtering-houses, accompanied by 

 its smaller relative, the chimango. " When an animal dies 

 on the plain the gallinaso commences the feast, and then the 

 two species of polyborus pick the bones clean," says Darwin. 

 These birds, although thus commonly feeding together, arc far 

 from being friends. When the caracara is quietly seated on 

 the branch of a tree or on the ground, the chimango often 

 continues for a long time flying backwards and forwards, up 



