Field Notes D.A. Bell April 7, 1990 At Battery Spencer (lowest bunker); Marin Headlands, Marin Co., Calif. [West] NW of Golden Gate Bridge. 14:15 - Tiercel Peregrine incubating on nest. Weather is overcast, 100% cover; low ceiling. Fog lifted about 1 hr ago. Tiercel very attentive, looking about. Power boat races are underway on the bay, underneath Golden Gate Bridge. 100's of people on cliff at Battery Spencer, spectators everywhere, helicopters, planes, 100's boats. 14:25 - Tiercel kek-kek-kek call at Turkey Vulture, but remained tight on nest. 14:29 - Tiercel turned eggs. 15:00 - Tiercel still on eggs. No signs of falcon today - looked at bridge, but didn't see her at the usual spots. Maybe all the helicopters forced her to take refuge on a cliff. Chronology of egg laying: 1st Egg Sunday, March 25. Light-colored egg. 2nd Egg Weds., March 28. Normal colored egg. 3rd Egg Friday, March 29.