In this edition for young readers adapted from the bestselling work written and illustrated by David Allen Sibley, readers will find a unique treasure trove of fascinating facts about birds, paired with more than 300 full-color illustrations—some life-size! The extraordinary world of birds is brought to life on the page. Did you know that many species of birds have sensory abilities that surpass those of humans? Or that some birds spend the entire winter in the air, and even sleep while flying? Have you ever wondered why birds have feathers? Or why they are a particular color? Have you noticed that some birdsong sounds like a musical scale? Maybe you’re more interested in “how” questions: How do birds actually fly or swim? How and why do some birds migrate? How do they find food? How do they take care of their offspring? Birds are not only beautiful and fascinating, but they also serve an essential role in our ecosystem. This book shows how birds and humans are intrinsically connected, sometimes helping and sometimes hindering each other. Perfect for dedicated birdwatchers—or for anyone who simply delights in noticing birds in their neighborhood. Readers can explore, share, and return to the pages again and again, each time gaining a broader appreciation for our enchanting feathered friends. ★ “An immensely entertaining and enlightening volume that will entice both adults and children.” — Kirkus Reviews , starred review ★­ “ A superior ­volume of ­well-researched facts and ­figures; a ­must-have for young bird nerds.” — School Library Journal , starred review “Sibley brings his adult study on the nature and behavior of birds to a younger audience. [The] arrangement [of text] into lists and the repetition of core concepts make it easy to digest , as does the book’s browsable structure. — Booklist DAVID ALLEN SIBLEY is the author and illustrator of the series of successful guides to nature that bear his name, including The Sibley Guide to Birds . He has contributed to Smithsonian, Science, The Wilson Journal of Ornithology, Birding, BirdWatching, North American Birds, and The New York Times . He is a recipient of the Roger Tory Peterson Award for Promoting the Cause of Birding from the American Birding Association and the Linnaean Society of New York's Eisenmann Medal. He lives and birds in Massachusetts. Introduction The Diversity of Birds Birds are dinosaurs [p. 81 bottom]. Some dinosaurs grew feathers more than 160 million years ago and gave rise to true birds. The meteor impact 66 million years ago wiped out more than two-thirds of all terrestrial species on earth, including all dinosaurs and all but a few bird species [p. 81 middle]. The general consensus is that there are about eleven thousand species of birds on earth today, and about eight hundred are found regularly in North America north of Mexico. These species are incredibly diverse, and a sampling of their remarkable adaptations and abilities are presented in this book. EVOLUTION—­NATURAL­ SELECTION­ ­AND­ SEXUAL­ SELECTION The incredible diversity of birds is the product of millions of years of evolution. Evolution operates by selection on individual birds, similar to the way breeders of roses or dogs select the characteristics they want to enhance in future generations. In nature, mortal threats like disease, weather, predators, and others remove the “less fit” individuals from the population. At the same time, members of the opposite sex select characteristics that are appealing. All of this affects which individual birds survive and reproduce, which then influences the characteristics of the next generation. Over the course of hundreds of millions of generations, this process leads to the entire diversity of life on earth. Natural selection is mediated by survival, Darwin’s classic “survival of the fittest.” This leads to the wide range of bill shapes, wing shapes, nesting habits, and so on, as birds with the best adapted features are stronger and healthier, raise more young, and pass along their traits to more offspring. Sexual selection is driven by mate choice, as each sex selects a mate for particular features. This can lead to extravagant plumage, as we see in the male Wood Duck [p. 177, Wood Duck]. Feathers THE ­FUNCTION­ OF ­FEATHERS When asked “What does a feather look like?” you probably think of an oval shape, a central shaft, and many barbs on each side (like the one shown here), but feathers are extremely diverse in structure and size. Similarly, when asked “What are feathers for?” you might think of flight or insulation, but feathers have adapted to serve a myriad of different functions. Feathers keep birds warm and dry, streamline the body, provide color and ornamentation, allow birds to fly, and more. Two of the key properties of feathers are very light weight and incredible strength. -Feathers did not evolve from scales. The precursors of feathers were bristle-like and hollow, and gradually evolve