156 BIRDS OF LA PLATA 



before it has time to sprout. While watching crowds 

 of these birds feeding on the ground, I noticed that 

 their manner was in striking contrast to that of the 

 C. picazmo, which has slow and dignified motions ; 

 for it hurried about, and snatched up its food with 

 such rapidity that the most animated motions of 

 other birds that feed in flocks on the ground seemed 

 languid in comparison. This excessively lively habit 

 is, no doubt, directly caused by the conditions of 

 life; the sterile soil and scanty vegetation of the 

 region it inhabits require in a species going in large 

 bodies, and subsisting exclusively on fallen seed, a 

 greater activity than is necessary in the rich fertile 

 region further north. 



Its song is composed of notes equal in length and 

 number to that of the Pica^uro, but its voice is 

 always hoarse, like that of the European Wood- 

 Pigeon, when his early spring song has a low, throaty 

 sound, as if the bird was still suffering from the 

 effects of a winter cold. 



The great body of these birds retire on the ap- 

 proach of summer from the Pio Negro valley, a few 

 only remaining to breed. Their nesting-habits and 

 eggs are like those of the Picazuro. 



