This is Scientific Americans 60 Second Science. I'm Karen Hopkins. Got a minute?

The redder, the better. And I'm not talking about beats, roses, or presidential candidates.

I'm talking birds.

Well, some birds.

In various species, red coloration in a male's feathers or beaks is an indication of fitness.

A splash of red can attract a mate or warn off a rival.

Now two teams of researchers have determined the chemistry that allows our flamboyantly

feathered friends to cloak themselves in crimson.

Bottom line, many birds eat plants that are rich in compounds with a distinctive yellow pigmentation,

which some birds can modify chemically to form the red pigment that becomes their calling card.

To tease out the details, the scientists compared birds that can make the red compounds with those that can't.

The first team studied the red canary, which was

created about a century ago by breeders who crossed the more familiar yellow canary with a bird

called a red siskin. The researchers comb through the genomes of all three kinds of birds to see whether red canaries got any reddening genes from the siskin side, genes that their yellow brethren lack.

Their search pointed them to a member of the

cytochrome P450 family. These are enzymes that are often involved in breaking down

toxins. The particular enzyme for turning yellow to red was at levels a thousand times higher in the skin of red canaries compared to their yellow fellows.

The second research team arrived at a similar conclusion based on studies of zebra finches.

Most zebra finches have a bright orange to red beak,

but one kind of mutant zebra finch has a yellow beak.

Turns out that these yellow beaked birds have multiple mutations in and around

their P450 genes, which pretty much cut the yellow to red enzyme levels in their beaks down

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