BIRDS OF AKGENTINA, PARAGUAY, URUGUAY, AND CHILE 171 



it may be j^itch dark. In olden times they were prized for their 

 watchfulness at night, which gave warning of the approach of any 

 possible enemies, and it is to this that the sentiment in Avhich they 

 are held at present is due. Though peons rob their nests continually, 

 comparatively few of the terus are killed, which may account for 

 their abundance in settled regions. 



The species was found in practically all of the regions visited. In 

 the Chaco where the country is broken by frequent tracts of monte 

 they were less common than farther south in more open country. 

 During winter they were frequently observed in pairs that often 

 seemed to have a restricted range where they were observed daily. 

 They traveled to some extent, however, and were frequently seen in 

 strong, direct flight, passing high overhead. In the Chaco back of 

 Puerto Pinasco they were seen at a distance of 200 kilometers west 

 of the Paraguay River. A female that I secured on September 6, 

 1920, at Kilometer 80, was about ready to breed. It is possible that 

 another form may be described from this region as this specimen, 

 in common with one or two seen from southern Brazil, has the black 

 line down the foreneck considerably restricted. 



The well-watered eastern pampas form the true metropolis of the 

 teru teru, as though the species frequents open, grassy plains, it 

 seeks always the vicinity of water. In eastern Buenos Aires the 

 birds were especially abundant and at the end of October apparently 

 were breeding. At this season they became especially pugnacious 

 in pursuit of passing hawks and storks, Avhile one even dashed 

 repeatedly at an inoffensive European hare that loped along ahead 

 of me. It Avas frequent to see two pairs of terus high in air in a 

 display flight in which the fully extended wings, marked promi- 

 nently with black and white, were waved slowly. The birds were 

 observed west to Carhue, Buenos Aires, but none were noted at 

 Victorica, Pampa, though I was told that they occurred there in 

 wet seasons. A few seen at General Koca, Eio Negro, were supposed 

 to be the present bird but may have been cMlensis. 



In Uruguay terus were common. On January 22 between San 

 Carlos and Rocha I observed several bands of 20 or 30 gathered on 

 open spaces on the banks of little arroyos running with clear water. 

 These bands, observed commonly until the end of February, were 

 composed of old and young, all less noisy than earlier in the season. 

 The birds rested or fed in loose flocks that ran aside to permit 

 passage of vehicles or men on horseback. At this season terus were 

 in molt and their resting places were strewn with cast feathers. 

 Grasshoppers, present in great abundance, were a favorite food, and 

 the birds on the whole must have a considerable economic importance. 

 A young bird only a few days old was captured near Lazcano on 

 February 7. An adult taken on the following day is representative 



