FIELD NOTES DONG BELL DATE: MAY 20, 1985 LOCATION: Alcatraz Island, San Francisco Bay, California WEATHER: Clear, sunny, hot TIME: 10:00 AM - 12:00 At Parade Grounds - attempting to trap adults using "Winkler's" modified gull trap. 10:30 set trap over nest w/ 2 eggs. A bird, the male, of a pair went in and sat on eggs as soon as I left the immediate vicinity. Caught this bird rather easily. Am now (10:42) waiting to see if its mate can be caught. The mate is at the nest and was in attendance when I grabbed the male from the nest. 10:57: the male (female?) went into the trap and sat on the eggs. Caught it too. (Nest #117), [Eggs from nest #20 also removed - as it was right in middle of helipad. 3 eggs in this nest]. The sexes of the pair I describe above were correct. The first bird caught on the eggs was the larger of the pair, a ♂. The second bird caught was the ♀. She weighed 10 gms more than the male, yet was smaller. A ripe egg was in here oviduct. They had 2 eggs in nest, which I collected.