J Players 1974 Oreopholus ruficollis 1 km E of Farmhouse by road, Estancia Medland, 35 km S. of Juan de la Cruz by road, Ptdo de Madariaga, Provincia de Buenos Aires, Argentina 20 February 8900 saw first individual of the fall (T) in the grassy fields before reading the turn-off to Tower Llanos. Solitary, alit. 7 March I note live only that since 20 February I have seen no Oreopholus. Tower Llanos, Estancia Medland, Ptdo de Madariaga, Provincia de Buenos Aires, Argentina 1 April 5 Oreopholus! on Grid 4 near the tower. What beautiful birds - a very fancy throat remaining in all but one, where it is a mottled brown. Black spot present on all. Foraging very much like Golden, even more so than does Zonibyx! Their call is between a whine and a chime - less than 1 sec duration. 3 April no Oreopholus on llanos. 11 April 1300- 11 Oreopholus with a mixed flock of other upland birds: Tyngite + Zonibyx. collected 1 (130). 1800- 17 Oreopholus in the on grid 4 and penetrating into the thicket patch to the S. one Zonibyx, with them as well as 12 Tyngites. Oreopholus scratched under the wing! - not believed it as Tchel would have predicted. By 1830 I had observed this thrice from a reasonably close distance. Watched Oreopholus foraging: appears to get from place to place like golden, then it pauses at a foraging spot; it runs between sites separated by a few ft, pauses, then runs again. But the details of the behaviour contrast from Fluvialis: once stopped at a foraging position, it leans over (legs bent) and rapidly moves its head up + down, as if the bird were probing beneath the surface of the soil. Occasionally, this is mixed with this action, there is a more exploratory jab. But typically there are several (2-5) up and down head movements, sometimes as many as 10, that takes several seconds to complete. Posture during this feeding motion is with the tail very much elevated. The running between sites is like a plover but there is a more pronounced head withdrawal as the bird runs from site to site: the gape is as follows - stand with head erect for 5-10 seconds, retract the head + run for 1-2 sec (perhaps as far as 3'), stand again, raising the head again, lean over and dig. Posture while standing is very erect, typically after digging it runs a step or two before standing erect again. The tail is wagged, apparently after eating. The tip is moved downward "1"-"2", with the whole motion