you’ll see the green shine on their dark head. Meanwhile, the female birds have brownish heads with messy tufts. For both sexes, the slender red crooked beak and clean head demarcation give the ...

The outer sheaths of birds’ beaks grow continually throughout their lives, but when they are properly aligned, the tips wear each other away and the beak stays straight and normal in length.

“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 ...

In Alaska during the mid-1990s, bird experts noticed an uptick in overgrown, warped beaks among black-capped chickadees. Now, using high-throughput RNA sequencing, researchers at the University of ...