Look closerBirds
Why goldfinches turn patchy gray-brown in late August and September
When: August to September
Once their late nesting season winds down, American goldfinches molt in late August and September, trading lemon yellow for gray-brown and looking oddly patchy in between.
Why this time of year
Goldfinches nest so late that many are only just finishing, and the molt that follows usually runs late August and September, which makes these the patchy weeks.
How to notice it
- Watch goldfinches at a nyjer or sunflower feeder, or on seed heads along a meadow edge.
- Look closely at the yellow birds for dull patches, and at the dull birds for leftover yellow.
- Keep checking week to week; by winter, males hold only a little yellow around the face, throat, and shoulder.
Try this with kids: Can you find a goldfinch that still has patches of bright yellow left?
Molt is the swap of old feathers for new ones, a few at a time, which is why the birds look patchy.
Safety
- Goldfinches pick up contagious diseases at crowded feeders; keep feeders clean and rake up spilled seed.
Sources
- allaboutbirds.orgBody molt twice a year, late winter and late summer; nesting waits until June or July when milkweed, thistle, and other plants have seeds for nest material and food; birds look patchy during molt; feeder disease caution.
- massaudubon.orgMassachusetts nesting runs late summer, July into September; after breeding, adults and young molt, usually in late August and September; goldfinches then gather into fall flocks.
- massaudubon.orgWinter plumage detail: males keep some yellow around face, throat, and shoulder; both sexes mainly grayish-brown; fondness for nyjer at feeders.
In the guide for August, September