This is bird node.

Many birds, like the Northern Cardinal, use the color red as a visual signal.

When you're trying to attract a mate or scare a rival, the

redder you are, the better. But most birds have the capacity to make red feathers,

even those that aren't red. It's thanks to the action of a gene

identified in intensely red pet birds known as Red Factor Canaries.

The Red Factor Canary is a hybrid, part Canary, part Red Siskin.

Researchers found that both those species have the redness gene.

But Red Factor Canaries have a thousand times more red pigment in their skin.

The difference? Red Factor canaries inherited the Siskin's genetic

switch that turns on the redness gene in their skin. So just having the gene is not enough. If the genetic switch in the skin

is turned off, no red feathers. Although most birds have the redness gene, only some are red, its presence suggests this gene has another role.

It produces red pigments in the eye that enhance color vision. Vision that helps a bird recognize a

signal, a flash of red perhaps in a mate or a rival.

For birdnout, I'm Michael Stein.