A NATURALIST IN BRAZIL 



and many a naturalist has been impressed by the fact that under 

 stones which in Europe would conceal Carabidae, one is surprised 

 almost always to find ants. In Brazil, therefore, a whole series of 

 birds have accustomed themselves to living on ants. The Bemtevi 

 and the "Scissors-bird," when the "Igas" — that is, the females of 

 the Driver Ant or Sauva — are scrambling all over the paths, fill 

 their crops with these formidable insects, and prevent the formation 

 of many a fresh nest of the mischievous Leafcutting Ants. But there 

 is also in Brazil a whole group of specialized "Ant-birds," containing 

 many species, which assist the Anteaters — mammals which have 

 adapted themselves to the same diet — to prevent these redoubtable 

 insects from gaining the upper hand. Of some of these birds, such 

 as the Fire-eye (Plate 28, Fig. 23), whose red eye glitters most 

 uncannily in its setting of black plumage, Dr. Snethlage has observed 

 that they seek out the great processions of the Driver Ants, not 

 in order to eat the ants themselves, but rather to devour the insects 

 which these savage marauders (of which I shall say something later) 

 drive before them. For days on end these birds follow the Drivers, 

 looking down on them from some branch near the ground, and 

 immediately seizing all the grasshoppers and beetles that hurry to 

 one side, thinking themselves already saved. 



But even the hunters of the insects must themselves be under con- 

 trol, and so they too are pursued by other creatures, which limit 

 their multiphcation. The insect-eating birds are eaten by birds and 

 beasts of prey, and the rodents, and other small mammals also, 

 have similar enemies. Thus one wheel of the great mechanism 

 gears into another, and there are whole trains of such interdependent 

 wheels. For example, the shooting of birds of prey may result in 

 the destruction of the cotton-crop. As I have already explained, 

 the cotton-pods are destroyed by the Rosy Caterpillar. This would 

 multiply far less readily were there plenty of the small birds known 

 as Sebitos in the neighbourhood. Now, if the birds of prey are 

 destroyed the Blue Ravens and Hudiis are rid of their most deter- 

 mined enemies. These birds, with their blue, white and black, or 

 blue, redj black and green plumage, are among the loveliest of 

 birds, but they have, like our jays, the regrettable habit of devouring 

 the eggs and nestlings of smaller birds, and where they are too 

 numerous they may prevent the propagation of a small bird like 

 the Sebito. For the sake of the smaller birds there must be large 

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