Above, a spectrogram (a visualization of sound ) of a song of the Northern Parula.
Among birds whose song include trills, the Northern Parula’s slightly rising buzzy trill, which ends with a sharp whistle, is very distinctive. Some say it reminds them of the sound of a zipper. Take a listen below.
This was recorded on the campus of Schoodic Institute near Rockefellar Hall. While singing the Northern Parula was hopping among branches as it foraged for insects in the hanging bearded lichen.
Perhaps lesser known yet also distinctive is another song of the Northern Parula. As noted in Pieplow’s Peterson Field Guide to Bird Sounds of Eastern North America, though geographically varied, the songs, interspersed with chiplike notes, usually consist of a couple of buzzy phrases, the first few slightly lower. In this partial recording below from our project (made along the bike trail near Frazier’s Cove on Schoodic Peninsula), chiplike calls precede two buzzy phrases. (The full recording can be found here.)