Why Don’t Birds Turn Gray With Age?

December 23, 2015 | Joanne Kennell

A brilliantly-colored Blue Jay sitting on a branch in winter
Photo credit: Mark Moschell/Flickr (CC BY-NC 2.0)

Revealing the mystery behind why we go gray, and birds do not.

You may be dreading it or maybe that day has already arrived, but as you get older your hair will start going gray.  Unfair, I know — but have you ever noticed that birds always have the same beautiful feather colors no matter their age?

It turns out that birds, instead of using dyes or pigments, are able to make changes to the nanostructure of their feathers, allowing them to create bright and vivid colors.  Using X-ray scattering at the ESRF facility in France, researchers from the University of Sheffield found that the Blue Jay, which ranges from white to violet, have a surprising level of control in producing their feather colors.  Researchers believe that Jays may use this control to recognize one another.

The Jay’s feather is made of a nanostructured spongy keratin material, just like human hair and fingernails, however the difference lies in the Jay’s ability to control the size of the holes in this material and fix them at particular sizes, which determines the color we see.  What this means is that a larger hole reflects a broader wavelength, creating the color white.  Conversely, a smaller hole results in the color blue.  They are also able to pattern different colors along an individual feather barbing — equivalent to having many different colors along a single human hair.

SEE ALSO: The Color Pink Doesn’t Actually Exist

Now if the colors of their feathers were formed using pigments, like with humans, the feather color would fade over time because pigments are not produced in the same quantity as we age.  However, nanostructures remain intact even as the birds age, explaining why, unlike us, birds never go gray.

According to Dr. Andrew Parnell, from the University of Sheffield’s Department of Physics and Astronomy, “Conventional thought was that to control light using materials in this way we would need ultra precise and controlled structures with many different processing stages, but if nature can assemble this material 'on the wing', then we should be able to do it synthetically too.”

The hope is that this research will lead to the creation of paints and clothing that do not fade over time.  Parnell added, “Current technology cannot make colour with this level of control and precision  we still use dyes and pigments. Now we've learnt how nature accomplishes it, we can start to develop new materials such as clothes or paints using these nanostructuring approaches. It would potentially mean that if we created a red jumper using this method, it would retain its colour and never fade in the wash.”

Could you imagine never having to worry about your favorite shirt or dress fading every time you wash it?  Or worrying about the sun fading your newly painted shed?  Maybe one day researchers will figure out how to stop us from going gray… the possibilities are endless!

Read next: The People Who Can See “Invisible” Colors

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