INTRODUCTION ix 



of a wandering disposition, like the European 

 Crossbills, the Waxwing, and the Short-eared Owl. 

 They have the gipsy habit or the Columbus-like 

 spirit of the poet's Stork, who goes forth to explore 

 heavens not his own and worlds unknown before. 



Finally, we have a multitude of species, both 

 resident and migratory, belonging to families that 

 have a world- wide distribution. Among these are 

 the Thrushes, Wrens, Pipits, Swallows, Finches, 

 Crows, Swifts, Goatsuckers, Woodpeckers, Cuckoos, 

 Owls, Hawks, Vultures, Herons, Storks, Plover, 

 Snipe, Duck, Rails, Gulls, Cormorants and Grebes. 



These universally distributed families are always 

 more numerous in the temperate zones than in the 

 tropics in relation to the entire number of species. 

 Thus they are relatively more numerous in the 

 temperate district of La Plata than in the Brazilian 

 Forest region. 



Undoubtedly South America is richer in bird life 

 than any other region of equal extent. The species 

 number considerably over 2,000, and one half or 

 something over a half belong to a single order 

 Passeres, or Perchers. Half of these again are in- 

 cluded in the Sub-Order Oscines, or birds with a 

 developed vocal organ the song birds* We see thus 

 how rich this region is in bird life in which the 

 songsters alone equal in number, if they do not 

 exceed, all the species of birds in Europe together. 



About a quarter of the entire number of South 

 American species inhabit Argentina, and about half 

 that number are found in the Plata district, which 



