Goldfinches nest last

by KEVIN STRAUSS

In our society, we seem to remember the first person who does something: the first man on the moon, the first woman on the U.S. Supreme Court. We also seem to notice the “firsts” in nature. We notice the first migrating robins or crows in the spring. We don’t often notice the last migrating bird in the fall. But being the first isn’t always the best in the animal world. Birds like the American goldfinch (Carduelis tristis) wait until August to build their nests when most birds have already fledged their young. The young birds are already flying in our forests.

These bright yellow songbirds spent the spring searching for food but ignoring the work of nesting and parenthood. Goldfinches stay in male and female “singles” flocks until mid-summer, when they start looking for a mate.

This isn’t because goldfinches are late bloomers, it is just that they need to time their nest building to coincide with the availability of bull and Canada thistle down. Bull and Canada thistles bloom in mid-summer and fertilized seeds form downy “parachutes” (similar to dandelion “fluff”) that help them travel on the wind. Goldfinches gather this downy material and use it to line their cup-shaped nests in the forks of small saplings or shrubs. These small birds usually lay four to six pale blue eggs in their nests.

You might think that nesting this late in the year would cause some problems for the goldfinch. But if the weather turns cold, the naked newborn finches are snug and warm in their “down-filled” nests. Nesting so late in the summer might also put these birds behind for their migration south. But many of our goldfinches live here year-round or if they do migrate, they don’t travel far. They do molt and change color, however. Male goldfinches, which are neon yellow in the summer breeding season, change to a duller olive-green color, more similar to the coloration of the female goldfinch. Both male and female goldfinches have black wings and tails.

Unlike many other songbirds--chickadees, nuthatches, bluejays, who are happy to feast on black oil sunflower seeds, your best chance of attracting goldfinches to your yard is by setting up a niger thistle feeder. Not only do goldfinches use thistle down for nesting material, they also use the seeds for food. The thistle provides some “one-stop-shopping” for our local goldfinches.

While Canada and bull thistles are a “weed” to some people and a problem in livestock fields, they a boon to goldfinches and some other wildlife.

The next time you are outside, notice how many of the things that we call “weeds” have an important role in nature.