Pearson 1983 = sociabilis? ctenops (red-cheeked species) with moustache Nov. 15. Estancia Fortin Chacabuco, went with Anita and Michael Christie to an area above a mallin 3 km S, 2 km W of Cerro Pintado. Saw 3 discrete areas with a large density of tusas burrows, many of them open, many plugged with grass cuttings, some with fresh dirt excavations and no earth cover. One area with lots of pumice but not wet or even damp. Cell with beautiful light black soil. Michael went home about 6 pm and Anita & I set traps in two of the colonies, returned to the car at , then returned to the colonies at 9:30. Ducks was about 9. Ate sandwiches in the middle of one colony after dark (1/2 moon, clear), then slept behind a Barberia at the edge of another colony even checking traps by flashlight (1 tusa, 1 also longi). We saw and heard no tucos, heard baroual. Saw 3 Roithrider. Nov. 16 Checked traps at dawn, no tucos, no Roithrider. Return to car, then picked up traps at 2 pm. Two more tucos, 3 also longi, 1 ctenops. Saw and heard no tucos, and saw only one fresh earth excavation among the hundreds of burrows. All 3 trapped specimens squadded rather than greasted. When Christie was returning home yesterday at 6:15, he stopped at one of the colonies and saw about 3 tucos with red shoulder emerged from the burrow, and several individuals were "singing": a bird-like, high- pitched trill? song. Phrased like St. longi but high-pitched. Several individuals within maybe 5 meters were singing. The groups of individuals seem to occur in colonies