Field Notes Doug Bell Location: Alcatraz I, S.F., Ca. Date: March 26, 1987 Time: 12:06 Tide: Outgoing. Weather: sunny, mildy. 12:06 - 12 birds on perimeter, 13 on platform of cistern; had been disturbed previously by person walking over platform. It looks like most the birds are resting, loafing. Many seem to be cold freezing. 12:02 - The bird of silver path land grappled with another on platform for 2 min. 12:17 - Watching pair 20 - both sitting on territory, resting, but watching other birds too. 12:23 copulation attempt in I.B. 12:23 - approach of mother bird in app. upright caused one bird to stand up. It then sat down again after picking at ground. 12:27 - both birds resting. 12:27 - Colony - most birds resting. Location: Alcatraz I, S.F. (o.) Date: April 5, 1987 Time: 9:46 Tide: Outgoing, half-low. Weather: Clear, sunny; light wind. At bird on cistern. Gulls seemed to stay alarmed longer upon my arrival. At 9:50 - copulation in I.B.. About 27 gulls on perimeter of cistern, and 12 birds in platform. New call - "yelp" (ascending), precedes long call. Pair 29 was chasing on spot, #4 landing & standing next to them just watching (silver-yellow). 10:10 - 29 gulls around platform, 16 on platform. 10:11 - watching pair "29": Male sitting on ground, F behind him standing. Both resting, just looking around. The M is doing several choke-yelps-arps, which fade into the guttural chuke while he is sitting. 10:20: most of the colony has calmed down. The F suddenly did aggressive upright, ran to "nest" spot below level of cistern, sneezing & followed. Both hopped down to the shelf + choked.