Birds are some of the most colorful animals on Earth ... which they stun before eating by banging the insects' heads on a branch. The paradise tanager (Tangara chilensis) is a 5.5-inch-long ...

An immature indigo bunting perches on a branch in Las Cruces, Costa Rica. The birds are known for their rich, deep blue hues. Photograph By CAGAN H. SEKERCIOGLU Ridgway's 1912 book, Color ...