transforming…

Spring is a time of change in many ways.  Over the past couple of weeks, I’ve watched the goldfinches (males, mostly) transform from the drab tan and gray winter plumage into their bright, golden, summer one.

american goldfinch male-

This male is just beginning the molt.

The process is rather gradual — growing feathers is an expensive and time-consuming process — and consequently, male Goldfinches in the spring exhibit variegated colors.

american goldfinch male-

The black feathers on the head are still coming in, but the body feather molt is almost complete on this male.

Like many songbirds, Goldfinches undergo two feather molts annually:  a complete body, wing, and tail molt in the fall, and a partial molt of just body feathers in the spring before breeding.

american goldfinch male-

Spring molt complete, this handsome fellow is ready for action.

The yellow color comes from dietary carotenoid pigments, which must be consumed while the feathers are coming in.  (Read more about pigment coloration in birds here.)  Millet seed provides much higher concentrations of carotenoids than sunflower and thistle seed (which are quite low), so perhaps Goldfinches change their diet slightly in the spring to increase their carotenoid uptake.

Studies have shown that the male Goldfinches that are brightest in color are the most successful in attracting a mate and have the highest levels of carotenoids circulating in their blood, which might be attributed to their greater success in seeking out the appropriate food sources.

7 thoughts on “transforming…

    • Thanks, Belinda. There is so much variety in the plumages of the male Goldfinches that come to my feeders right now. It surprises me that their molts aren’t more synchronized actually.

    • That’s the difference between shooting through the window glass and shooting outdoors. Also, bright morning sunlight sure helps get a sharper image. 🙂

  1. Goldfinches were surprisingly absent from my feeders most of the winter. I even swapped out the thistle thinking it was stale – they are so fussy. They finally showed up last weekend wearing their spring plumage.

  2. I see goldfinches only rarely, so it’s hard for me to appreciate the gradual process. Your wonderful shots, Sue, really show how the goldfinches look as they are going through the transformation process. As another reader noted, that last photo is awesome in its color and sharpness–good light really helps. 🙂

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