192 BIRDS OF LA PLATA 



They usually go in flocks of about forty or fifty 

 individuals, and fly rapidly, keeping very close 

 together* On the ground, however, they are always 

 much scattered, and are so reluctant to rise that 

 they will allow a person to walk or ride through the 

 flock without taking wing, each bird creeping into 

 a little hollow in the surface or behind a tuft of grass 

 to escape observation* During its winter sojourn 

 on the pampas the flock alv/ays selects as a feeding- 

 ground a patch of whitish argillaceous earth with a 

 scanty, withered vegetation ; and here, when the 

 birds crouch motionless on the ground, to which 

 their grey plumage so closely assimilates in colour, 

 it is most difficult to detect them* If a person stands 

 still, close to or in the midst of the flock, the birds will 

 presently betray their presence by answering each 

 other with a variety of strange notes, resembling the 

 cooing of Pigeons, loud taps on a hollow ground, 

 and other mysterious sounds, which seem to come 

 from beneath the earth* 



In the valley of Rio Negro I met with a few 

 of these birds in summer, but could not find their 

 nests, 



Durnford, however, who found them breeding 

 in Chupat at the end of October, tells us that 

 the nest is a slight depression in the ground, some- 

 times lined with a few blades of grass* ' The eggs 

 have a pale stone ground-colour, very thickly but 

 finely speckled with light and dark chocolate mark- 

 ings ; they have a polished appearance, and measure 

 1.3 by .8 inch*" (Ibis, 1878, p* 403.) 



