Just Exactly 'How' Do Bird's Feathers Change Color From Season To Season ?

We have many birds of many varieties near our home .And it's pretty amazing to see the finches change from a dull gray during winter , to a bright stunning yellow in the spring !!

I've always wondered how this happens. .. .. Does anyone know ?Just Exactly 'How' Do Bird's Feathers Change Color From Season To Season ?
Birds can manufacture melanins in their own bodies but can only acquire carotenoids through their food. Flamingos are a fine example of this; if they do not get the right molecules in their diet, which occur naturally in their wild diet, then they lose their stunning pink colouration. Early zoos had great problems keeping their flamingos coloured before this was understood.



Birds, of course, exhibit a much greater range of colours than blacks, browns, reds, oranges and yellows. The blues, greens and other iridescent variations arise from the physical presence of minute structures on the surface of the feathers which reflect only one wavelength of light. This creation of colour via refraction or light is not unique to birds, some fruits and insects such as the Morpho butterfly use physical microstructure to reflect selective wavelengths as well.



Blue and White are normally a structural colour as is green, though green may often be a mixture of structural and pigmental iridescence.



Abrasion plumage. When we look at a bird we see usually only the tips of the contour feathers. These tips can be a different colour to the rest of the feathers. Because feathers get worn away at the tips this can cause a bird's plumage to change colour as the feathers age. Many passerines use this method to have one plumage in winter and a more colourful one in spring. They gradually acquire their breeding plumage through abrasive wearing away of the dull or cryptically coloured tips to reveal the brighter plumage beneath. Snow buntings and Chaffinches are two good examples of this.Just Exactly 'How' Do Bird's Feathers Change Color From Season To Season ?
I may be wrong, but I believe that what you are seeing are different variety's of Finches.



The gorgeous Yellow Finches are Migratory Birds from further North, they Winter down in Fla.

Be Blessed in Christ Jesus !

Minister......( Outraged )



( sigh........i guess i was wrong......sigh )
(just from my upbringing) It's God's way of showing new life. And that all things, old. My become new.



[pretty good for a Monday, huh]
Yes, it's the same birds. They moult or lose and grow new feathers each year. They put on their best brightest clothes in the spring during mating season, it makes the girls come'a'runnin'. During the winter months they put on their camouflage cloths. No need to give the predators too big of an advantage. I have a lot of house finches that visit my feeder. Right now they are mostly bright red over most of their bodies. In the winter you can't tell them from the female. I live in Kentucky and neither the House Finch nor the Gold Finch migrate. They are here all winter, but they all look like females in the winter.
The American Goldfinch is my favorite bird and I love to watch them turn from the dull mustard yellow to the vibrant yellow that they are in the spring and summer.



The process is called moulting. It is just like shedding or losing teeth, etc. The old feathers fall out as the new ones grow in.



The male American Goldfinch moults for two reasons. The dull feathers he obtains in the winter are a warmer coat for protection against natural elements. The bright yellow color helps the male bird to deter predators from finding the birds' nest site in the spring.
The American Gold finch is the one that you are speaking of. They molt. They do this several times per year. The males are the bright yellow ones. They do that to attract some bird lovin'. The female molt but do not vary much in shades of color for camouflage reasons. Sitting on the nest needs to be a secret so cats don't find and eat them. Not just cats but you get my meaning.
They are not the same feathers. The feathers they grow in the spring are bright yellow breeding plumage. Then those fall out and in the fall they are replaced with grayish winter plumage. Sexual selection is apparently driving the feather color difference. In the spring, a bright male probably is more appealing to females, but in the fall, there is no breeding going on, and a duller color is probably advantageous to avoid being eaten.