66 CHARLES DARWIN 



The number, lameness, and disgusting habits of the car- 

 rion-feeding hawks of South America make them pre-emi- 

 nently striking to any one accustomed only to the birds of 

 Northern Europe. In this list may be included four species 

 of the Caracara or Polyborus, the Turkey buzzard, the Gal- 

 linazo, and the Condor. The Caracaras are, from their 

 structure, placed among the eagles: we shall soon see how 

 ill they become so high a rank. In their habits they well 

 supply the place of our carrion-crows, magpies, and ravens ; 

 a tribe of birds widely distributed over the rest of the world, 

 but entirely absent in South America. To begin with the 

 Polyborus Brasiliensis : this is a common bird, and has a wide 

 geographical range ; it is most numerous on the grassy savan- 

 nahs of La Plata (where it goes by the name of Carrancha), 

 and is far from unfrequent throughout the sterile plains of 

 Patagonia. In the desert between the rivers Negro and Col- 

 orado, numbers constantly attend the line of road to devour 

 the carcasses of the exhausted animals which chance to 

 perish from fatigue and thirst. Although thus common in 

 these dry and open countries, and likewise on the arid shores 

 of the Pacific, it is nevertheless found inhabiting the damp 

 impervious forests of West Patagonia and Tierra del Fuego. 

 The Carranchas, together with the Chimango, constantly 

 attend in numbers the estancias and slaughtering-houses. If 

 an animal dies on the plain the Gallinazo commences the 

 feast, and then the two species of Polyborus pick the bones 

 clean. These birds, although thus commonly feeding to- 

 gether, are far from being friends. When the Carrancha 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 and down, in a semicircle, trying each time 

 at the bottom of the curve to strike its larger relative. The 

 Carrancha takes little notice, except by bobbing its head. 

 Although the Carranchas frequently assemble in numbers, 

 they are not gregarious; for in desert places they may be 

 seen solitary, or more commonly by pairs. 



The Carranchas are said to be very crafty, and to steal 

 great numbers of eggs. They attempt, also, together with 

 the Chimango, to pick off the scabs from the sore backs of 

 horses and mules. The poor animal, on the one hand, with 



