JPMyers 1974 Thino Thincocorus tomicivorous Tower Llanos, Estancia Medeland, 35 Km S. of Tucumc by road, Trito de Madariaga, Pcia de Buenos Aires, Argentina 3 March They're here! while on the llanos a duck & sp looking for buffy roost & watched what I first thought was a buffy flying up from the thistle, high, circling in a broad path (radius 100m). Each time it went through the NW/NEward part of the circle, it did a peculiarly can-breeflylike flight, but one I had seen solely Thincocorus in Chubut & Santa Cruz during last October-November: the "wind display", where a male lifts fly up into the wind, opens the wings and soars, with wings appraised downward. (handing out of page) Although then the bird swooped down exceeding fast following each soon. Instead of landing, however, as the did last summer, this bird rose quickly again + circled. The third time ended with the bird landing in a ragged grass area - 6" high. I tried unsuccessfully to spot it, because by that time I doubted it was a buffy. Especially so because of the landing, which was particularly abrupt. Then, 15 minutes later we got a good look at another Th., which hurried out of a solitary road beneath a thistle. 4 March 1015 searching through thistle I found 2 Thincocorus. Either they are juveniles or have muffled. Must collect. 1930 - after dark, in same area what night but saw no Thincocorus. 5 March 0930 - in some location as yesterday found 4 Thincocorus sedosnajus, 2 relatively solitary, and 2 flying in together. Collected the latter birds (092, 093). The feather front on the wings was particularly annoying in both three birds: most feathers coming out with potato food. In 093 found seeds, cold pods, and little leaves in a seed crop (?). Both ad. 07+? A few feather follicle showing in each. 7 March visited some area where collected 5 March. No sedosnajus visible. 13 March 1800 - collected a sedosnaja from same area today. Fathers present. Maybe same flock as seen earlier today the birds were feeding in a tight flock in an open area in the thistle patch. ground cover too low to Salicarnia and some other thick lined plants (but broadland, very short), as well as dandelion-hypers. The sedosnaja could be seen picking at the seed/seedheads of the latter plants. Both 07+ and 09 in the flock. 900 m W of Linear Grid along Arroyo Chico, Estancia Medeland, Pte de Madariaga, Pcia de Buenos Aires, Argentina 15 March spotted 3 Thincocorus while latter hiking along Arroyo. They were in the bushy area on the banks of the Arroyo.