National Geographic : 1946 Dec
That Hazy Spotted Oval Is an Egg Unlike other birds, Mother does not tuck the egg under her breast, for it might slip off. Using her bill, she draws herself over it. A knothole, a scar on a limb, or parallel boughs all serve as nests (page 807). Gilbert Grosvenor A Balancing Egg Rocks inItsCradle onthe Bough Fairy terns scorn nesting materials; they use naked branches. Father helps Mother select a dent in the bark; there sheaccurately deposits hersingle egg. Despite stiff sea breezes, it holds position likeaswaying, lead-weighted toy. Look in the Tree Fork!