The champion of loudness! Males can hit 125 decibels—louder than a rock concert. This Amazonian bird reaches 116 decibels, ...

The Andean condor is considered threatened but is in far better shape than its California cousin. Reintroduction programs are working to grow populations of these South American birds.

Even among migratory birds, the red knots' migration is harrowing. Running from South America to the furthest tip of Greenland, it's a journey of more than 9,000 miles. "Those birds gather in ...