i8a BIRDS OF LA PLATA 



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 T6rus by the strange behaviour of two individuals 

 amongst them, and I stayed to watch their proceed- 

 ings. 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 drum- 

 ming 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 hoiu* 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 



