The Book of Eggs introduces readers to eggs from six hundred species - some endangered or extinct - from around the world and housed mostly at Chicago's Field Museum of Natural History. Organized by habitat and taxonomy, the entries include newly commissioned photographs that reproduce each egg in full color and at actual size, as well as distribution maps and drawings and descriptions of the birds and their nests where the eggs are kept warm. Birds' eggs are some of the most colorful and variable natural products in the wild, and each entry is also accompanied by a brief description that includes evolutionary explanations for the wide variety of colors and patterns, from camouflage designed to protect against predation, to thermoregulatory adaptations, to adjustments for the circumstances of a particular habitat or season. Throughout the book are fascinating facts to pique the curiosity of binocular-toting birdwatchers and budding amateurs alike. Female mallards, for instance, invest more energy to produce larger eggs when faced with the genetic windfall of an attractive mate. Some seabirds, like the cliff-dwelling guillemot, have adapted to produce long, pointed eggs, whose uneven weight distribution prevents them from rolling off rocky ledges into the sea.