A shared shape rule, the power cascade, governs most bird beak growth. It links modern birds with extinct dinosaurs.

On top, the bird has a brown helmet-like spot that breaks the contrast between the yellow body and the comically proportioned scarlet beak. Whether it’s sitting on a tree branch or in flight ...

While many birds have basic brown or black bills ... nicknamed “the clown of the sea,” has a stunning beak that turns bright orange, yellow, and blue during the breeding season.

The small brown bird weighs around 16 grams (roughly half an ounce) and has black and yellow bands along with a large beak. The finding, which was reported in the science journal Nature ...