The dating behavior and late nesting of those gorgeous goldfinches

Last night, I was sitting in a friend’s south Minneapolis backyard enjoying a temperate summer evening and a fine glass of scotch. Bird calls were distracting me as they often do when I’m outdoors. Good friends know not to be offended when I rarely make eye contact during conversations outdoors. I could hear soft chattering overhead in his tree. The friend asked, “What do you hear?”

“Goldfinches,” I answered, “and it sounds like they’re on the third date.”

It’s a strange time in summer. Migration is underway for shorebirds, some sparrows and even a few hawk species. However, one species is just getting started with nesting: the American goldfinch. Many of us use goldfinches as a harbinger of spring since they change from their dull olive-colored winter plumage into a vibrant yellow for summer. But despite the molt, they wait until mid to late July to actually copulate and lay eggs.

It’s a fascinating strategy. The goldfinches wait until fibrous plant material is available like milkweed or thistle down to weave their tight little cup nests in shorter trees.

Smaller birds have a quick turnover rate in the nest, they incubate for about two weeks and the young leave the nest about 11 to 13 days after hatching. A savvy goldfinch pair might pull off two broods despite starting the nesting season in July.

Goldfinches are strict vegetarians. They’re not into the insects like so many other backyard birds are in early spring. By waiting until mid to late summer to nest, that ensures there will be plenty of ripe seeds and fruit to feed a few extra mouths in the nest. Goldfinches eat all kinds of food beyond just Nyjer (also known as thistle). They love sunflower seeds whether offered in a feeder or a flower that has gone to seed. My sister has had them devour petunias that went to seed in flower boxes and when

I’ve been on birds surveys, I’ve watched them chow down on goat’s beard.

This vegetarian lifestyle also helps them to avoid raising cowbirds. Brown-headed cowbird females lay their eggs in other bird nests so you might see them being raised by orioles, cardinals or yellow warblers. However, the American goldfinch diet doesn’t have the nutrition a growing cowbird needs. According to Cornell Lab of Ornithology’s All About Birds page, a cowbird chick rarely lives past three days in a goldfinch nest. Beautiful and smart.

All About Birds.

So keep an eye and an ear to your yard and watch your goldfinches. I’ve found adults feeding young in the nest well into September. Listen for the quiet begging calls in shrubs or young trees. 

Categories: NatBlogs, Sharon Stiteler, Social Media

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