SWEDEN – As well as in humans is the red color of love in birds. In many bird species gives red a benefit in mating times.

Researchers have now found an enzyme in red canaries that converts the yellow pigment to the red pigment in the eyes and feathers. The study has been published in Current Biology.

Red attracts females

Several bird species previously had a yellow color, but today have red feathers. Scientists believe that it is due to sexual selection that has driven the birds with red feathers.

Red males have simply been more successful in getting to mate, because the red color proved that the male was a good chap, fresh and healthy, according to Leif Andersson, professor of functional genomics at Uppsala University and one of the researchers behind the study.

It tends to vary between different species the color that is used the most. But it is an honest signal of quality. There are examples of blackbirds where the yellow beak color is proven to have access to nutritious food, says Leif Andersson.

Two essential genes

The researchers wanted to find out which gene that causes the red feathers and therefore examined the red canaries. The red canaries came about when the yellow canaries crossed with red siskin in the early 1900s.

After several generations of crosses with the yellow canaries, the red canaries retained the red color gene from red siskin and the rest of the genes from the yellow canary.

The researchers discovered two genes that affect the advent of red feathers. The first gene converts the yellow pigment to red and the other gene controls the evolution of feathers.

It is interesting to see if this is a common mechanism among birds, and it will certainly turn up new studies on this, said Leif Andersson.