their chicks display vibrant markings inside their mouths, each with a unique pattern. The markings gradually fade as the chicks mature. The sword-billed hummingbird is the only bird with a beak ...

“normal” beaks (examples shown of a petrel and a gull) and a bird with a tactile bill-tip organ (a tinamou, close relative of ostriches and emus and which has an ancestral bill-tip organ ...

The flat beaks of ducks typically have soft edges for sensing food in the water and comblike lamellae inside to sieve out insects, seeds, and other morsels. (Photographed at Sylvan Heights Bird ...