Ford 2408 Gymnogyps californianus March 2, 1976 February 3 Hopper Canyon, Calt. adult, & one quickly left. At 5:25 counted 12 at Big Cave alone & 13th on East Cliffs as before. Of the 12, 2 at pool area atop Big Cave & 2 others (it appeared like a youngster with wings flopping, "begging" to be fed) were atop cliff over the cave. Before 5 p.m. 2+ on ledge or in pothole seemed perched flat as if settled for the night but standing later. At 5:30 at least 3 in potholes near Big Cave; only 1 visible atop cliff. One perched flat on Whitewash Ledge. As the number of vultures in Hopper Basin fluctuates so, even in winter, the area may not be absolutely essential to vulture survival. 5:35, one shifted from cliff top to Whitewash Ledge - the ledge appeared thus: Three atop Roost Tree, well separated, thus: of o 5:45, the birds still appeared as diagrammed except the flattened one now gone from the ledge. None visible on cliff tops - I can't recall ever having seen any atop cliffs late in the evening; apparently cliff tops are undesirable roosts. "Sunning" post-me is apparently infrequent before going to roost in late afternoon and evening.