Friday, September 3, 2010

An early September gift

photos: S. Hochgraf
American Goldfinch nest

Earlier this week I startled a pair of American Goldfinches from their nest in a White Pine.  This very common little songbird has pretty interesting habits.

They tend to nest late in the summer - when thistle down (or similar plant fiber) is available for nesting material.  They also are one of the few songbirds to feed primarily seeds to the nestlings.

The female constructs the nest entirely on her own in a spot which is protected overhead from the weather, open on one side for quick escape to nearby cover - and - often visible from below - which was definitely true of this construction.

One egg is laid each morning until the clutch is complete.  This late in the season a clutch will be smaller than an early-season clutch.  I must have discovered the nest on day two of egg-laying (Tuesday), and to avoid disturbing the birds, I won't return until next week.

The female alone will incubate the eggs, taking only very short breaks.  The male will bring partially digested thistle (and other plant) seeds, and feed her on the nest.  Incubation may take up to two weeks, and the chicks will usually pip within a day of each other.

After two weeks of feeding by both parents, they'll be fully fledged and ready to leave the nest - within hours of one another.  The young will depend on the adults for food for an additional three weeks.  Have you been adding this up??  We're looking at the third week of October before the kids are on their own!

I've condensed all of this information from wonderful research compiled from countless hours of field work by many ornithologists - and presented in user-friendly format by the good people at Cornell's Laboratory of Ornithology.
The photos are my own.

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