One of the latest nesting songbirds, American Goldfinches don’t get started on nesting until late June or early July. This appears to be timed with the life cycle of the late blooming thistle plant which provides both nesting material and food for goldfinches. This correlation between the thistle seed ripening and goldfinch nesting may explain why goldfinches seem so much more attracted to Nyjer feeders during nesting season. Often in late fall throughout the winter goldfinches are more interested in golden safflower and shelled sunflower than Nyjer™ and Nyjer mixes.
The bird seed sold and commonly called “thistle” is actually Nyjer. Nyjer™ is a trademark name of the Wild Bird Feeding Institute- the scientific name is Guizotia abyssinica. The plant has a yellow flower not the pink to purple bloom of the native Canadian thistle plant. If you see the Canadian thistle plant on your property the seeds could have traveled on the goldfinches’ plumage but it didn’t germinate from your feeders.
Goldfinches favor nesting in the fork of a deciduous shrub or small tree but can be found in small conifers. The nest is a small compact cup of plant fibers, grass, spider silk lined with plant down and hair. In addition to feeders, providing nesting material will assist adult birds during this busy season. Suet feeders filled with dog, cat, horse or human hair or The Best Nest Builder hung in a bush or from a shepherds hook provides great backyard entertainment. It’s a wonder the birds can see to fly with their bills so stuffed with nesting material pulled from these items.
The female incubates the clutch of 4-6 pale blue eggs in the nest for 10-12 days and only has one brood a year. The male arrives nearly hourly to feed her regurgitated seeds. American Goldfinches raise their young on seeds, unlike other songbirds who typically feed their young insects. Adult goldfinches partially digest seeds and regurgitate them for the young. The adults feed the fledglings for 11-17 days after they leave the nest.
by Minnetonka Store Manager CAROL CHENAULT