180 BIRDS OF LA PLATA 
prey generally. Its noiMcry and irascible temper 
are spoken of by most travellers and naturalists ; 
for no person riding across the pampas could possibly 
overlook the bird, with its screaming protests against 
all trespassers perpetually ringing in his ears; but 
they have all omitted to mention the singular habit 
which this bird has of associating in sets of three 
for the purpose of amusement or play. Each couple, 
as I have said, live always together on their own 
pretty well-defined plot of ground, which they 
jealously guard from intrusion. Yet if you watch 
a pair of them for a while you will presently see 
another bird—one of a neighbouring couple—rise 
up and fly to them, leaving his own mate to take care 
of home; and instead of resenting this visit as an 
intrusion, they welcome it with notes and signs of 
manifest pleasure. Advancing to the visitor, they 
place themselves behind it, and then all three, keeping 
step, begin a rapid march, uttering loud drumming 
and rhythmical notes in time with their movements, 
the notes of the birds behind coming in a rapid 
stream, while the leading bird utters loud single notes 
at regular intervals. The march ceases, the leader 
stretches out his wings, still emitting loud notes, 
while the other two, with puffed-out plumage, 
standing exactly abreast, stoop forward until the 
tips of their beaks touch the ground, and, sinking 
their voices to a murmur, remain for some time in 
this singular posture. The performance is then over ; 
the birds all resume their natural attitudes, and the 
visitor takes his 'eave. It is quite certain that this 
