دانلود کتاب Beaks, bones, and bird songs : how the struggle for survival has shaped birds and their behavior

"Reveals the strange and wondrous adaptations birds rely on to get by."--National Audubon Society When we see a bird flying from branch to branch happily chirping, it is easy to imagine they lead a simple life of freedom, flight, and feathers. What we don't see is the arduous, life-threatening challenges they face at every moment. Beaks, Bones, and Bird Songs guides the reader through the myriad, and often almost miraculous, things that birds do every day to merely stay alive. Like the goldfinch, which manages extreme weather changes by doubling the density of its plumage in winter. Or urban birds, which navigate traffic through a keen understanding of posted speed limits. In engaging and accessible prose, Roger Lederer shares how and why birds use their sensory abilities to see ultraviolet, find food without seeing it, fly thousands of miles without stopping, change their songs in noisy cities, navigate by smell, and much more.  Read more...