BLACK-FACED IBIS 121 



They walk rapidly, stooping very much, and probing 

 the ground with their long, slender, curved beaks, 

 and appear to subsist principally on the larvae of the 

 large horned beetle, with which their stomachs are 

 usually found filled. So intent are they on seeking 

 their food that the members of a flock often scatter 

 in all directions and wander quite out of sight of 

 each other ; when this happens they occasionally 

 utter loud vehement cries, as if to call their com- 

 panions, or to inform each other of their whereabouts. 

 Frequently one is seen to lift up its wings as if to 

 fly, and, stretching them up vertically, to remain 

 for fifteen or twenty seconds in this curious attitude. 

 At sunset they all rise up clamouring and direct their 

 flight to the nearest watercourse, and often on their 

 way thither go through a strange and interesting 

 performance. The flock suddenly precipitates itself 

 downwards with a violence wonderful to see, each 

 bird rushing this way and that as if striving to outvie 

 its fellows in every wild fantastic motion of which 

 they are capable. In this manner they rise and 

 descend again and again, sometimes massed together, 

 then scattering wide apart in all directions. This 

 exercise they keep up for some time, and while it 

 lasts they make the air resound for miles with their 

 loud percussive screams. 



In Patagonia I first observed this Ibis roosting 

 on tall trees ; and, according to Azara, it possesses 

 the same habit in Paraguay. He says that all the 

 flocks within a circuit of some leagues resort to one 

 spot to sleep, and prefer tall dead trees, bordering 



