Birdie Num Nums

I installed a thistle seed goldfinch feeder in my frontyard sanctuary last winter, but was surprised to see a bunch of brown birds feeding from it. Turns out they were American Goldfinches, but with their winter (non-breeding) plumage. Since entered spring a couple days ago, they've started to molt and are now getting their summer plumage. Thanks to Wikipedia, I've also learned that the yellow color is produced by carotenoid pigments from plant materials in their diet. In other words, the thistle makes them yellow. Who knew!

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