"We've uncovered a system where all red parrots use the same set of molecules to color themselves," McGraw said. "It is a unique pigment found nowhere else in the world. We are fascinated at how parrots are able to do this.
"The fact that there is a single set of molecules unique to and widespread among parrots, suggests that it is a pretty important evolutionary novelty, and one we should carefully consider when we think about why parrots are so strikingly colorful," McGraw said.
McGraw has been studying the colors of birds for seven years. He first became interested in the behavioral significance of bird colors as a form of visual communication within a species (e.g. to denote status or attractiveness). As he studied these aspects, he wanted to understand more about what makes the colors of the birds possible, and then focused on "deconstructing the color into its component parts."
McGraw said an interesting aspect of the five polyenal lipochromes that provide the red in parrots, is that the pigment is found only in the bird's feathers and nowhere else in the body of the bird, indicating that parrots manufacture these molecules internally and directly at the maturing follicles of the growing, colorful plumage.
In addition, these pigments may play a valuable role in maintaining the health of parrots. McGraw cites an independent study on the parrot pigments that suggests that they can act as anti-oxidants to quench free radicals and potentially protect cells and tissues in the body from oxidative damage.
Now, McGraw says, he's interested in learning more about the connection between the red colors and anti-oxidants within and among parrot species, as well as "to specifically explore the balance of naturally and sexually selected costs and benefits to becoming colorful.
"Parrots are unusual among birds, in that they almost without except
Source: Netherlands Organization For Scientific Research