Saturday, March 20, 2010

When Do the Goldfinches Return?

That is a good question! The American Goldfinch is one of my favorite backyard songbirds because of its butterfly like flight and delicate song.

Many customers think that goldfinches disappear in the winter. Actually, in the fall, all the goldfinches molt into an olive brown plumage. During the winter months both male and female goldfinches look similar but continue to actively feed in Michigan.

In fact they are the only bird in North America to go through a complete molt two times a year. In the spring the male turns bright yellow with a black cap, wings, and tail, and white rump. The female keeps the duller brown color and lacks the black cap.

Right now, as the photograph shows the birds are in transition. Just as the daffodils bloom, the male goldfinches exchange their dull winter coat for their bright yellow plumage.
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The males need to be bright to attract a mate and defend their territory from other males. Research also suggests that as testosterone in male birds increases, so does the level of carotenoids, the chemicals that create the bright coloring on birds' feathers, beaks, and legs. The female stays brown to blend in with the trees when she is sitting on a nest of eggs later in the summer.
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Gardening Trick for Goldfinches
Habitat can be a key to attracting Goldfinches. In this case you do less work, not more. Don't worry about dandelions and don't cut off the tops of your Marigold, Zinnias, Cosmos, or Coneflowers...Goldfinches love them.

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