In the past few decades, ornithologists have noticed some the birds' yellow feathers have mysteriously turned red. (See National Geographic's backyard bird identifier.) At first researchers ...

Smash wood from above. Why did I wait so long to look at this yellow bird? Why? It is one of the first ones you get - and way better than the blue or red bird. I really don't know. Oh, you don't ...

Hill said that if the bird has any red feathers on its body at all, then it’s not a yellow cardinal, as the mutation makes those birds incapable of having feathers that color. “There’s no ...

One is xanthochroism, a genetic mutation found in insects and some birds which causes red pigments to be replaced by yellow. For some, this is a matter of differences in absorption of food ...