DeBenedick's 1964 March 8 Chalan Bay, Cocos Island, Costa Rica was a very soft 3 quarter hour like an elaborate Geospiza, this quality but higher pitched. They have an ascended "whee" tooting whistle and the "seeew" high-pitched whistle of the other species of Geospizines. The only other landbird I saw were 5 Yellow Warblers along the beach. White Wattlebirds were fairly common in the tree tops, but flushed on approach. I managed to shoot one. A beautiful bird with black eye, black eye ring, a black tipped blue bill blue > black , and blue feet and legs with white webs to the feet. I had horrible luck shooting small birds and missed everything ! I managed to hit 3 finches and Ted Papenfuse got 2 more and 2 Yellow Warblers for me on the beach while I watched. He caught +1 Grebe under little along the beach. The Red-footed and Brown Boobies all roosted in the trees as did the pigeon birds. I saw only 3 dark Noddies, Anodius, but they were too far out to be identified; cups very clear and prob. they are Black Wattlebirds. There was a 12 year hanging Gull in the Bay, and this complete black tail band and black outer primaries were clearly seen; The forehead was light and the back was grey. Billee shot an adult Brown Booby. It had yellow feet. One of the midshipmen caught an immature Frigatebird. It has a white head and a buff chest band; the bill, feet, and eye ring are pale blue and the darker feathers have a purplish sheen. Must check the adults but I think