JPMyers 1973 Calidni melautas Grid 9 (Farmhouse Puddle), Estancia Weedland, 35 Km S of Juancho, Provincia de Buenos Aires, Argentina 20 December sampling Piedtail head positioning, solitary bird (0620) Down, Down, Up, Down, Down, Up, Down, Up, Up, Up, Up, Down, Down, Up, Down, Down, Up, Up, Down, Down, Down, Down, Down, Down, 15 down, 10 up). This bird is not within the vicinity of any other piedtail (minimum of 20 m); I have seen no interfering by it with others, and thus cannot guess as to its status. at 0900 birds coalesced into a large flock due to human disturbance - Piedtail collected (39) in the 1,0 area, 0920 followed one Piedtail for feeding data (head position) Bird in a Flock: Up, Down, Down, Down, Up, Down, Down, Up, Up, Down, Down, Down, Up, Down, Up, Up, Down, Down, Up, Stopped feeding. 11 Down & up 23 December. Distribution of piedtails in grid today different from that of 20 December; sharpest difference is that the lack of any numbers in the (3,-)'s today. 12/20 many were feeding in (3,0), (3,1), but today almost none. Instead they are more concentrated in the century the grid. The difference is element certainly due to the fact that the (3's) are essentially day to day, whereas before they were surrounded by water. Many flocking Piedtails present today, in fact there appears to be a cohort of noticeably fewer individuals engaged in any significant amounts of aggression. Time of day? A large flock? There are many more birds today - inverse dependence of aggression density? However there are a few birds that are foraging solitarily - enough work they may reveal space overhead again. 2000 many Piedtails still on Grid - do they sleep here ? Grid 1 (Farmhouse Puddle), Estancia Medeland, 35 km S of Juancho, Provincia de Buenos Aires, Argentina 24 December 0550 - signs of territoriality in a Piedtail - in (0,1) (0,2) region (I failed to pick him up in the first grid count after morning because he was just reatch the grid) - watched him Supplant another Piedtail at 0549 - now again, another bird flew into wonder of (0,2) and (0,3) in middle - he chased it away. Many of this birds feeding efforts are directed at the small clumps of diet shelleyout above the level of the water. Beside him is a wet asking tillorial - in (0,3), (0,4) region chasing other (w.k.) out of (0,4) and (0,3). They Two possibly intraspecifically territorial birds are feeding together - within 2 feet or less from another. Some any sort of aggressive demonstration. 0555 this Piedtail in middle