5 P W Myers 1974 Journal 61 Punta Raga, 15 Km N of San Clemente del Tuyu by road, Rio de Gral Lavalle, Rio de Bs Aires, Argentina 28 March (contd) and 8 White-rumps, the rest of Bay A is noticeably deficient in shorebirds. Among the birds present there is very little sign of overt interaction—certainly no territoriality. The distance between us + them would allow whisper subtle interaction to pass unnoticed. 1820—Parasitic jaeger harrying gulls + terns, the shorebirds on the beach rise en masse at its approach. 1850—in the channel described on the previous page there is a fairly tight flock—10 WR within 10 x 10 m as well as 14 godwit, all oriented in the same direction moving up the Arraigo. In the last 20 min they have moved 150 m over an area in which there are no other WR, and only 2 Ch. fallaxkens and 1 other H. godwit. Thus it is difficult to state that there is a lack of space here—what there is is a very tight clumping of birds (note) in the habitat and, at least in this instance, organized systematically. Returned to car slowly along mudflat, reaching it ~15 min before sunset (i.e., @ 1945). The falling tide situation has not greatly altered my morning’s impression that Punta Raga is not the shorebird haven it had been made out to be. The most numerous shorebird was Ch. fallaxkens, followed by White- rumps. Total numbers of these birds, on the S side of the main mudflat, did not exceed 1000/species. None of the other species exceeded 100/species: Arenaria interpres, Calidris canutus, American oystercatcher, Hudsonian godwit, Black-bellied plover. A few species, alba, Erythraea + whimbrel were less numerous than the 2nd class, probably under 30 birds. Generally absent (likely) were Southern lapwing, See Arenaria, the Fuscicollis, Parasitic jaeger spp accent. 29 March. Sun rose at 0758. Temp—11° at dawn, no wind clouds <5%. We went back to the area where we had observed yesterday afternoon, the mudflat lying along the SE side of Punta Raga, appro- ached from a Hunting & Fishing Club W of the lighthouse. 0845 we were walking down the mudflat from the club. Tide is out very far but may still be refecting. At the club the mud is ~75 m wide, after which a channel of several hundred metres width prevails. Across the channel is another strip of mud similar to that on this side. As on this side, the mud does not remain equivalent in width. In some places the flat is over 150 m W. To the North, across the channel, it continues for aeration. Immediately across the channel from the club at this time was a flock of 80 WR and 24 Hudsonian godwits. Further E along the opposite side as the flat turns south away from Punta Raga, an additional shore-