JP Myers 1974 Journal 46 Arroyo Chico, Estancia Medland 35 kms. S. of Juancho by road, Ptdo de Mladaniaga, Provin de Buenos Aires, Argentina 14 March (cont'l) Neotropical Cormorant 0,1(1); Speckled teal 0,9(9); Cocoi heron 1,1(2); B.h. gull 0,4(4); Correndera pipit 2,0(2); Rufous-backed negrito 1,5(4). After proceeding down Arroyo searching for banded birds, we were set upon by a series of extraordinary clouds which came racing out of the south accompanied by wind and rain. The clouds were low, not extensive in width, but stretching from horizon to horizon in a dark grey strip. There were 5 of these in succeesion, the last passing over in less than 20 minutes. Their swift approach, strange appearance, and violence, were remarkable. Because of the rain we were forced to abandon a run down the Arroyo (banks became muddied). 6 banded birds located, however (see resighting charts). Rather than retreat to the farmhouse we parked the car just above the bank by subunit 6 in order to observe the WR flock present there (see WR spp accent) After determining that only one territorial WR used this subunit (controlling the northern part of OW), and that non-territorial birds foraged over the raft, we left driving to subunit 4. Then, after watching several WR feed, I collected one that was "filter- feeding" (see spp accent), also picking up some of the substrate upon which it was working. On subunit 4 I repeated the collection, only this time taking a "search/peck" feeder, along with its substrate. With these goodies we returned to camp. 15 March Began running linicargrid 0600 weather ominous: completely overcast (heavy) with a slight S wind already [illegible]. Temperature at 0600: 2.5° Grid totals: White rump 8,77(25); Charadrius falklandicus 19,10(30); Black- Bellied Plover 0,1(1); Greater Yellowlegs 0,2(2); Black-necked Stilt 10(1); Southern Lapwing 10(6); Southern Screamer 10(1); Cocoi heron 10(1); Speckled teal 6,1(7); B.B. Negrito 0,3(3); Brown hooded gall 0,1(1); Maguari Stork 0,1(1). Then turning about at 10, we ran down the Arroyo seeking out banded WR. Totals: White-rump 23,59(77); Charadrius falklandicus 20,27(47); Hudsonian godwit 1,7(5); Greater Yellowlegs 1,2(3); Black-necked Stilt 2,8(1); Southern Lapwing 6,5(11); Southern Screamer 0,2(2); Neotropical Cormorant 0,1(1); Speckled teal 4,6(10); Brown-headed gull 0,3(3); Geocitta crinicollis 1,0(1); Rufous-backed Negrito 0,5(5). The change in white-rump sandpiper numbers since yesterday [illegible].