VIZCACHA-HUNTING AND GIANT SNAKES 407 



As the sun set, large flocks of blue-crowned parrakeets 

 flew screaming overhead to seek their sleeping-quarters 

 in the tops of the gnarled, stunted trees ; and gray-throated 

 parrakeets hurried to their bulky stick nests to chatter 

 and quarrel before settling for the night. The latter species 

 is an abundant bird in the Chaco of Brazil and Paraguay as 

 well as in the Argentine. In the Argentine its range ex- 

 tends eastward into the province of Tucuman, while it is 

 most plentiful in Santiago del Estero. They are extremely 

 noisy and live and travel in flocks of a dozen to several thou- 

 sand individuals. Should one approach a tree in which 

 a band is feeding or resting, all chatter is hushed. But the 

 birds crane their necks and noiselessly clamber to points 

 of vantage from which they suspiciously eye the intruder. 

 Then there is a sudden burst of wild screams as the whole 

 colony takes wing and swiftly departs at great speed. They 

 feed largely upon the thistle and on cactus fruits as well 

 as on grain when it is to be had. 



The nests vary in size from those containing not more 

 than an armful of twigs, and occupied by a single pair of 

 birds, to huge structures weighing several hundred pounds 

 and harboring a dozen familes. Frequently three or four 

 nests are placed in the same tree, and usually a number of 

 trees in a given area are occupied. The ground beneath 

 the domiciles is strewn with a thick litter of old nesting 

 material that has fallen from the disused bulky masses 

 above. 



The nesting cavities are in the under-side of the "apart- 

 ments," and entrance to them is gained through tubular 

 openings underneath, which prevents opossums from en- 

 tering them. It is not unusual to find a family of the mar- 

 supials living in a cavity in the upper part of the structure, 

 but so strongly are the twigs interlaced that they are un- 

 able to tear their way through the thorny mass to the tooth- 

 some morsels that are so tantalizingly near. The birds 

 occupy the nests throughout the year and it is rare to find 

 them entirely deserted at any hour of the day. The eggs 



