FIELD NOTES Doug Bell LOCATION: Alcatraz Island; San Francisco Co., San Francisco Bay, Calif. DATE: 13 Dec. 1987 WEATHER: clear, sunny; winds NE 20 mph TIME: 13:23 -16:00 TIDE: 3/4 m of rock exposed At Blind or Cistern Gulls are scattered throughout the entire Bay area. No gulls on cistern, or any other nest site when I arrived. However, at 13:26 2 birds landed on IB - ad. Westerns. Note - at Fisherman's Wharf saw lots of gulls - Western, Glaucous-winged, Mew, California, Bonaparts. Many Calif. & Mews gulls around SF. 13:29: 2 more WG on IB roof. All 4 birds w/in 3 yds of each other. 13:30: 5 gulls now on IB 13:33: 9 gulls on IB roof. One gull, upon landing, elicited Long Call from another bird. These 2 began alarm yelps and did an aggressive upright along side one another. A third bird joined in, but the newcomer was chased away by one of the birds. 13:37 - all birds split. Killdeers (2) on IB roof. Flocks of DC Cormorants proceeding past Alcatraz. About 50 Western Grebes on bay west of island. 13:40 - large mixed flock of gulls, cormorants, grebes on water west of island quite spread out - nearly 300+ birds. Spent the rest next hour watching birds around the island. 15:25 - 2 WG on Cistern. Long call, one did aggressive upright at another &. & joined first &. One chose on ground. 15:30 - One & agg. upright directed against another &. Randy & shoved up !: silver/yellow bands on left leg. 15:34 - all birds away. Pair landed on IB, long called, then alarm yelps. 15:35: 6 birds on IB. 15:36 - 17 Gulls on IB, one pair landed, mewing, choked on IB at near edge. Of 17 gulls, one is a GWG. 15:37: 27 gulls now. Many drinking water. The pair from 15:36 in now mewing mewing together, ran over to cement loader. 15:44: 63 gulls on IB, including one Herring Gull and 2 GWGs. More arriving.