“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 ...

A bird beak is the most important resource it has, and every species has one solely designed for survival. Birds use beaks for just about everything: building nests, feeding their young ...

Under these drastically changing conditions, the struggle to survive favored the larger birds with deep, strong beaks for opening the hard seeds. Smaller finches with less-powerful beaks perished.