April 19. Syon Brack arrive with night vision goggles. also Fidel Valerio, Christie, + Patricia. Took Syon out to Seven Marton, then went Rother Hamlet at Estancia La Fragua east of Estancia Panto Marono. Went up Coro Oto in a.m. to cut bamboo pole now known at the Prestoe Blanca level and above, Senpas beginning to turn. Flamingos on the lake at Panto Marono, now equipped with Park signs and called Soguna for juncos. Camped on the upste east of Panto Marono, about 1 km farther east than usual. Inexplicable numbers of Rattlesnake droppings. Heard two at 6 p.m. "Tuc-a-tuc." Mostly clear, cold, calm, Morn ½ + x April 20. Fowlglights 8:30-9:00 with moon, color, saw 2 Panto Marono Rattlesnakes in Berberia clumps. Then between 9:30 and 10, mostly moonlight, saw about 5, shot 3 of them, all solitary although 2 of them rose then 20 m apart, all in or edge of Berberia island. Fowlglights again 3:30 to 4:45, color, overcast, heavy frost. Saw no Rattlesnakes, 2 hares, heard barn owl. At dawn (8 a.m.) overcast and the frost had turned to dew. Heard tucos from 3 directions simultaneously at 3:30 a.m., another at 4:45 a.m. Perhaps the van deer siding stunt sets them off? In the morning one