LINES OF MIGRATORY FLIGHT 151 



various species of ducks, seed-snipe, small flycatch- 

 ers {Lessonia rufd), that run about on the open 

 ground, a migrant form of house wren, with other 

 birds, appear in the Province of Buenos Aires from 

 more southern regions at the beginning of winter, 

 and as summer approaches, again withdraw to the 

 southward. A goatsucker (Xhermochalcis longiros- 

 tris) is a regular summer migrant from Brazil to 

 Patagonia. Occasionally one becomes lost in pas- 

 sage across the pampas and descends in some Ar- 

 gentine estancia, where it is greeted with amazement 

 by wondering peons, who seek its feathers as a po- 

 tent charm by whose force a suitor may hope to gain 

 favor in the eyes of his inamorata. Near Buenos 

 Aires the jacana, the sulphur-bellied flycatcher 

 {Myiodynastes solitarius)^ two species of martins 

 {Progne elegans and Phaeoprogne t. taper a) ^ and a 

 small swallow {Jridoprocne albiventris) are summer 

 visitants, which at the approach of cold retire to the 

 north, as does the bulk of some other species, a part 

 of whose individuals are sufficiently hardy to brave 

 the moderate cold of winter in that latitude. 



Even in northern Paraguay, in the edge of the 

 tropics, the spring migration is easily evident, as 

 with the advance of September Podager nacunda, a 

 bird related to the nighthawk, passes in regular 

 evening flights toward its summer haunt in the 

 pampas, hawking for food as it travels in rapid zig- 



