Unlike birds whose plumage is mostly blue, the green coloring of a green bird’s feathers is the result of pigment, not a trick of the light. These birds’ emerald green, lime green, chartreuse, or ...

Transforming an aldehyde into a carboxyl group can fine-tune feathers from red to yellow But how psittacofulvin pigments shift shades was unclear. An enzyme called ALDH3A2 alters the chemical ...