Biel Arvey Journal 1965 Sept. Trip to Farallon Islands via USCGC Willow from Yerba Buena Island, at 8 AM. Day overcast, slight NW breeze, Temp in 60's° In S.F. bay Western and Ring Bill gulls seen at mornings and further out we pick up elegant or royal terns also. At first I thought these to be all Royals because of bill shortness, thickness and general size but now am undecided because of the range of variation seen of these characters. In the middle of the bay these terns are quite prevalent, sometimes fly in front of ship as if to see what is "scared up" by the bow. Once I observed a Herman's gull giving chase to one which was carrying a fish in bill, and was accompanied by another tern. The terns stayed together as the gulls chased after them, and called loudly, as did the gull. No actual aggressive contact was seen however. Often I saw a loose group of 3 or 4 terns flying over the same area, probably pursuing the same school of fish. In the vicinity of the Golden Gate Bridge, where a broad zone of turbulence is present, many terns of these species feeds at the interface. The turbulence is due to tidal action I presume, and cause a surface rippling much like the rapids in a stream, and I sure that there is a good current running here. Herman gull are seen very frequently and almost any dark bird skirting on the surface proves to be this species.