J.P. Myers 1974 Journal Linear grid subunit 3, Arroyo Chico (11,16) Estancia Viedeland, 35 Km S. of Juandio by road, Palo de Madriguera, Provincia de Bs. Aires, Argentina. 25 November (cont'd) to literally push the water downstream. Many event, there were several considerable #s of fasciollis along the linear grid - in fact I sighted 5 birds banded last year and 2 since August, the majority of which I'd not seen in the Arroyo for a month or more. Although I made no total count, I estimate there to have been fairly over 100 fasciollis. Anyway, tracking up the linear grid, the two densest concentrations (now both conveniently located on already gridded subunits), appear sub-3 + sub-4. When we passed by at 0715, more were on 3 than 4; thus when we reached the end of the grid we decided to work subunit-3 for another calculation of % territorial birds and related habitat variables. Returning to 3, we found at 0805 that many of them had left, leaving a group of ~15 in the area. We opted to remain there + make the calculations. See % TB Calculation #6, also Linear grid following data book, and the Calidris fasciollis sp. count. We counted birds from 0825 to 1025, censusing at 10 min intervals (13 samples). During the final 10 samples, the total count was broken down into territorial and non-territorial categories, and a % TB figure was calculated for each of these 10 censuses. Finally, the ten %TB figures were averaged. Results: 4.8 birds/sample; 36.7% territorial birds present/sample. During the observation period not only did the # of birds decline, but the consistency of territorial defence increased (until a few lapses). For the early portion of the observation period, some interactions were confusing as to their degree of space-specificity. This is very no doubt due in part to the complications induced by increased numbers. But I think it fair to say that intermediate birds were present and eventually left, given that perhaps as a result of the constant action of the 2 consistent territorial birds using parts of the grid. We are not sure how long the flock has been present, nor indeed, if the 2 main territorial birds came in with the stock influx. I do know that the flock was not here 20 November, and that few birds are ever in this unit under the conditions which must have prevailed here yesterday morning after the rain. Thus, I think it reasonable to suggest that