4How Birds Work goes beyond the typical field guide to show us not only what birds look like but why. Why do many owls have asymmetrical ear openings? (Hint: It helps them pinpoint prey; see page 40.) And why does the Grey Heron rest on one leg at a time? (Hint: Not because it's tired; see page 66!) Birds boast a spectacular array of adaptations suited to their incredibly diverse diets and habitats. In this in-depth handbook, discover the ways they're even more astounding than you know--inside and out. Detailed analysis and illustrations illuminate:

• Skeleton
• Muscles
• Circulation
• Digestion
• Respiration
• Reproduction
• Feathers
• Colors and Patterns
• And much, much more!