If it is not singing, the Northern Waterthrush, a large wood warbler and not a thrush, can be recognized by its bobbing body and wagging tail. However, its loud, ringing song is the most diagnostic characteristic of this species, and allows one to distinguish it from its look-alike relative, the Louisiana Waterthrush. The primary song of the Northern Waterthrush has three parts, which are said to sound like a vigorous, rapid “sweet sweet swee wee wee chew chew chew chew.”
The Northern Waterthrush also has a flight song which is given on its breeding ground, typically in the evening. This song usually starts with loud, sharp, chips of increasing frequency, delivered from the ground or a low perch. The bird then flies upward through and above the canopy, singing snatches of primary song but quicker and longer, framed in a hurried jumble of half-call/half-song notes.
To hear the primary song of the Northern Waterthrush, go to http://langelliott.com/mary-holland/northern_waterthrush_1_NY.mp3. (Sound recording © Lang Elliott – langelliott.com & miracleofnature.org)