BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 95 



trees scattered across a prairie, and at my appearance greeted me 

 with harsh squalls. An adult female was taken. Another was ob- 

 served on July 30. At the Riacho Pilaga, Formosa, a female in 

 streaked juvenal plumage was killed on August 7, and an adult 

 female on the following day. Others were recorded here until Au- 

 gust 19, and one Avas seen near the town of Formosa on August 24. 

 In the region about Puerto Pinasco, Paraguay, they were fairly 

 common and an adult male was collected September 15. 



This form has customs similar to that of Mtlvago chimango, a 

 species that it replaces in the north, but is more of an inhabitant 

 of wooded areas. The partly open, partly forested Chaco seemed 

 fitted especially for its needs, and here it was encountered where 

 scattered trees furnished shelter. The birds are scavengers in habit 

 and feed on any waste animal food that is available. They also 

 bear a bad reputation among the housewives on the estancias for 

 their propensity to filch young chickens and ducks, and, as the kiriri 

 comes familiarly about buildings, its depredations maj^ at times be 

 considerable. My " squeaking " to attract small birds from dense 

 coverts always drew these small hawks when they were about, and 

 their squalling calls were often annoying when I was straining my 

 ears to catch some faint bird note from the surrounding thickets 

 or trees. Carrion hawks often came while I was engaged in clean- 

 ing bird skeletons, and walked about on the ground to pick up bits 

 of flesh that I threw out to them, while it was necessary to hang 

 skeletons put out to dry in places where they were secure from the 

 sharp eyes of these prying marauders. The ohimango is a bird of 

 weak flight, flapping and sailing rather slowly, and never, so far 

 as I am aware, is it directly aggressive to other birds unless it en- 

 counters young or individuals that have been injured in some way. 

 Adults when on the wing appear light in color on the body and tail, 

 with a light bar in either wing. Their call, a harsh squall, is remi- 

 niscent of that of Ihycter ater. 



POLYBORUS PLANCUS PLANCUS (Miller) 



Falco Planeus Millee, Var. S'ubj. Nat. Hist., 1777, pi. 17. (Tierra del 

 Fuego. ) 



The carancho was almost universal in occurrence throughout Ar- 

 gentina and Uruguay, as it ranged throughout wooded regions as 

 well as on the open pampas. None were observed at the localities 

 worked in Rio Negro and Neuquen in northern Patagonia, but this 

 was due in all probability to the short time occupied in field work 

 in those regions. The carancho, as the bird is known in the south, 

 is a bird of strong flight, though it does not delight in soaring or 

 circling in the air as is customary in vultures and many hawks. 

 Its vigorous form, with contrasted light and dark colors, is one that 



