FIELD NOTES DOUG BELL LOCATION: Alcatraz I., SF Bay, CA. DATE: 2 May 1987 TIME: 9:28 - TIDE: Low,(incoming): 1.5m exposed Weather: clear, sunny, calm. No wind. at blind on cistern: 9:22:32 gulls in perimeter, 8 on platform. Immediate activities observed: most building from collecting by pair laid in front of blind and on cliff off territory 1. Copulation heard. While recording from 9:30 - 10:10 - 2 copulations recorded and 2 food transfers seen - one transfer of midshipman, which the male did not want to give up, and one transfer of a sardine. 10:13 - 30 gulls in perimeter, 5 on platform. 10:20- colony - 11 birds incubating. The weather is so calm - ca 20 gulls sitting on ES or powerhouse roof; about 20 bathing near exposed rocks. 10:37- Pair 5- one bird is incubating, other standing next to it, head-tucked. So far I've seen a couple nest exchanges. In one case /pair 3 - the S approach meowing, I got up and left nest for him. In another case /pair 7, the bird sitting did a partial long call and then stood up. 10:50- colony - an imm (subadult - brown shoulders.) on platform with bill of nest material - was chased by other birds, but still on platform: 27 birds in perimeter, 9 on platform. 11:08 - big fight by pair 5 - one bird badly banded and immediately grabbed the other's bill - grappled over 2 min, while all gulls long-called. A stranger then tried to rape female of pair 3! - twice attempted this. So far - 3 rapes this morning. 11:17- Wind picking up - 11:22 Copulation on power house. 11:28- Pair 32 - both birds in territory, one standing in nest, other next to it.. Gull seen carrying nest material. Gull seen carrying large palm frond.