124 BIRDS OF GREAT FOREST REGIONS. 



derful system of aerial sentinels continually exercising 

 a vigilant look-out upon everything that passes below, 

 is maintained by vast armies of winged watchers spread 

 over an enormous territory, which embraces almost the 

 whole of the tropical and subtropical regions of the 

 earth, wherever in fact the heavy forest does not 

 interfere with their operations. As however their call- 

 ing is exercised entirely by sight, and not by scent, 

 the dense canopy of foliage in a great forest country 

 effectually screens the earth from observation birds 

 of prey, of the vulture type, are therefore conspicu- 

 ously absent and those of the hawk tribe alone exist. 

 The hawk species are however generally numerous in 

 forests, as they prey upon the feathered tribes which 

 in very great numbers sun themselves upon the tree 

 tops, where in most of the tropical regions they find 

 an abundant sustenance upon the nuts, berries, and 

 other fruits as well as upon the countless legions of 

 insect life which there luxuriate under the full influence 

 of the solar rays. Such fruits and flowers grow and ripen 

 in abundance not only upon the great trees themselves 

 but also upon the infinite multitude of creepers which 

 spread themselves over their crowns in the full glory of 

 prolific Nature in these climates. Hawks will also sail 

 down through the branches and snatch their prey even 

 from the ground itself: the forest may therefore be 

 regarded as the principal hunting ground of many of 

 the hawk tribe, its inmost recesses being almost every- 

 where vigilantly hunted by these keen-eyed plunderers. 



While however the forest, both by day and by night, 

 is constantly the hunting ground of the sharpest eyes 

 in existence, owned by birds of the hawk and owl 

 species, it is a noteworthy fact that it also forms the 



