JPMyers 1974 White-rump 35 Km S of Juancho by road, Grid 3, Estancia Medland, Ptdo de Madariaga, Pcia de Buenos Aires, Argentina 5 January Collected 2 WR (059, 063) from flock of mixed shorebirds in a quiet marsh of Grid 3 - a newly flooded depression with no mud, only thick, low emergent grass and decayingillo. No info on spacing system of birds other than that they were not solitary. Grid 1, Estancia Medland, Ptdo de Madariaga, Pcia de Buenos Aires, Argentina. 1930 Saw only one WR in the vicinity of Grid 1 - a banded(!) bird, just, only USF+WS band - I think the lighting was bad. But if it did have only the aluminium band that means that 82/52015 (banded 1 January) recovered. 7 January 1045 passed through grid 1 one way back from Grid 2. In same spot as last night was a banded WRump - but this one was RIGHT YELLOW banded 31 December. It is possible that last night's bird was R.Y. also. [illegible] Grid 2, Estancia Medland, Ptdo de Madariaga, Pcia de Buenos Aires, Argentina Collected one WR in a futile attempt to get a known territorial sectoral. The pest had flown, landed among a flock of WR. I fired at him but instead got (063). Rk II Pond at Farmhouse Rd, Estancia Medland, Ptdo de Madariaga, Pcia de Bs Aires, Argentina 10 January 0830 - been here an hour, sitting in car watching WR + T. in hope of collecting kinds of known behavior. Rain just stopped. Between 2+4 WR have been here continuously on a little spit of the pond adjacent to the road: [sketch: pond, mud, grass, road, X US, A, B, E] The WR ranged within the area noted as mud, [illegible] occasionally going up into the E. inset stretch of grass. One of the WR - maybe JW - I can see an out-of-place feather or bird with a white tip - is definitely territorial, excluding other WR from area A. Another definite territorial bird is in B. "A" chases birds from a distance of 5y to 10 m, on both sides of the pond, also a little into the road. The other's ("B") seems to have a smaller area, and I have seen it sneak into "A" while "A" is to the W. This happened when another bird came into [illegible] between B; "B" chased, I continued on into A. Although