YPECAHA RAIL 167 



they all immediately wheel about and begin the 

 exhibition. 



Whilst screaming they rush from side to side as if 

 possessed with frenzy, the wings spread and agitated, 

 the beak wide open and raised vertically. I never 

 observed them fight or manifest anger towards each 

 other during these performances ; and knowing the 

 pugnacious spirit of the Ypecahas, and how ready 

 they are to seek a quarrel with birds of other species, 

 this at first surprised me, for I was then under the 

 mistaken impression that these gatherings were in 

 some way related to the sexual instinct. 



Whilst watching them I also remarked another 

 circumstance. When concealing myself amongst the 

 rushes I have been compelled to place myself so 

 disadvantageously, owing to the wet ground, that 

 any single bird straying accidentally into the open 

 space would have discovered my presence immed- 

 iately ; yet the birds have entered and finished their 

 performance without seeing me, so carried away 

 are they by the emotion that possesses them during 

 these moments. But no sooner has the wild chorus 

 ended, than, aware of my presence, they have fled 

 precipitately into the reedsu 



We frequently speak of our familiarity with the 

 habits of the species we have long and carefully 

 observed in a state of nature ; yet the knowledge so 

 gained must necessarily be exceedingly imperfect, for 

 with many shy vigilant birds it is next to impossible 

 to see them without being seen ; and no bird, con- 

 scious of being watched, will act unconstrainedly 



