FIELD NOTES Doug Bell LOCATION: Alcatraz I., SF Co., Calif. DATE: 8 May 1987 TIME: 9:25- WEATHER: clearing fog, sunny mild-moderate wind TIDE: high, rock just exposed. On cistern in cloud. 32 gulls on perimeter, 10 on platform. (9:28). Of these, it looks like 23 birds are incubating. Since there is a moderate wind blowing, many gulls are soaring about the island. 9:35 - watching colony, stronger on platform - wandering about - causing agg. uprights. Copulation heard but not seen. 9:45 - fog thickening +++++ dust visibility ca 1 mi. 9:47 - Pair 9 - male incubating & standing next to nest. Banded bird with silver, yellow landed on platform - was chased away. Pair on west cliffs copulating (9:50). Male mallard was on the cistern when I came up. Bird on 33 jumped off nest to chase intruder. Two separate courtship feeds seen - one pair 30 [recorded morning, head storing] was of fish, the other on 18 - also fish. At end of watch pair 9 - no change, & still on eggs.. 10:05 - watching colony. It looks like pair 30 may have changed composition. 9 landed NW US F4 W land. Copulation heard, not seen. 10:10 - 27 gulls on perimeters, 8 on platform. The bird on nest 33 long called to me that landed nearby - the one that landed has a band on its left leg - both F's. 10:26 - Pair 7 Cross-collecting gull seen on cistern. Pair 7 began copul. at 10:28 but interrupted - I think because a number of flying gulls are alarm calling. Of pair 7, neither bird is sitting on nest. 10:20 - 2 birds aerial mewing. 10:39 - 32 gulls on perimeters, 10 on platform watching colony - copulation lack of cistern. Seems to be much fighting, uprights at mea 26/34/28 : 10:50 - Pair 14 one bird incubating, other sitting nearby. Copulation heard, but not seen