sawyer_n_a_dawson's Identifications

I heard it through my open window near my birdfeeder. A Goldfinch was nearby but All About Birds does not record this sound for Goldfinch. A bird was at the feeder but I could only see its tail and rump unclearly; could not ID. I don't know who made the sound. If needed, I can also post the blurred photo of the bird's rear end taken through a dirty window.

A note re the sound. The bird would be silent for more than fifteen seconds straight. Once it vocalized every two seconds. To make my recording short enough for iNat to load, and still include more than one vocalization, I cut a lot of the silent parts down to a few seconds.