168 CHARAD1UID/E. 



life and when one of these vagrants passes near a pair he is imme- 

 diately invited to join them, and, when he alights, all go through the 

 performance together with great zest. In this case, however, as soon 

 as it is over, the strange bird is attacked with great spirit and chased 

 away ; and if by chance he comes down again near them, they hasten 

 to drive him up with increased fury. 



While watching their antics, which the Gauchos call the Teru's quad- 

 rilles, a curious subject of inquiry suggested itself to my mind. It 

 appeared to me that its manner of playing has had a reflex effect strong 

 enough to mark the bird's whole character language, bearing, and 

 habits being coloured by it, and even the domestic relations interfered 

 with. And with regard to the latter point, though it is the rule that 

 each cock bird has only one hen, I have known several instances of a 

 cock with two hens, the two females laying their eggs in one nest and 

 taking turns in sitting on them. I have also found instances of two 

 males to one female ; and in one case, where I watched the birds, I 

 noticed that when the female was on the nest the males stood over her, 

 one on each side. 



I once had my attention drawn to a large concourse of Terus by the 

 strange behaviour of two individuals amongst them, and I stayed to 

 watch their proceedings. It was in the dry hot weather, and a great 

 many birds had congregated to drink at a lagoon. Some hundreds of 

 them were standing about, quietly preening their feathers, and in the 

 middle of the flock two birds were conspicuously marching about, stiff 

 and upright as a couple of soldiers engaged in some military exercise, 

 and uttering loud notes full of authority. Every few minutes a fresh 

 bird would arrive and alight at some distance from the water, on which 

 the two noisy birds would bustle up, and, ranging themselves behind it, 

 run it with loud drumming notes to the margin; then, standing close 

 together, they would wait till its thirst was quenched, after which they 

 would run it away to some distance from the water, of which they 

 seemed to have made themselves dispensers. For over an hour I 

 continued watching them, and every bird that arrived was conducted to 

 and from the water in this ceremonious manner. 



Occasionally several couples unite and soar about in a compact flock ; 

 they divide into sets of three birds each, then hover for some time, all 

 waving their wings exactly in time and screaming their notes in unison, 

 and these movements seem like an imitation in the air of the usual 

 marching and drumming performance on the ground. 



The breeding-season of the Terus begins as early as the month of 

 June in favourable seasons; severe cold, drought, or other causes 

 sometimes delays it to August. The nest is a shallow circular hollow 



