The paths of different birds look like double helixes, flowing strands of hair, and migrating serpents, and they beckon with calls that have definite meanings.

How and why birds navigate the skies, travelling from continent to continent xe2x80x94 flying thousands of miles across the earth each autumn and spring xe2x80x

A richly illustrated, state-of-the-art field guide for identifying European passerines in flight—the first of its kind Opening up new frontiers in birdwatchin

United Airlines Flight 93, which took off from Newark Airport the morning of September 11th, 2001, is perhaps the most famous flight in modern American history: