The Tennessee warbler is very active, short-tailed, and generally nondescript. The male is most distinctive in spring, when his gray crown contrasts with an olive-green back. Females, fall males, and immatures have a yellow wash underneath. In all plumages, the white or whitish undertail contrasts with the bird’s darker, grayish (adult) or yellowish (immature) breast. Females and immatures have two very faint wing bars, but you won’t find much else in the way of distinguishing marks.
The Tennessee warbler’s chipping song has three parts, with the third part faster and louder than the first two.
Keep this drab songbird in mind while scanning mixed migrant flocks in your backyard or neighborhood park. During migration, you may find Tennessee warblers mixed with other warblers, chickadees, and other mixed flock feeders. They often feed on outer branches, but they can be seen low in shrubs and even in weeds.
Tennessee warblers nest across much of Canada and in some northern U.S. states. During spring migration, Tennessee warblers are usually found high in deciduous trees, and they migrate mainly west of the Appalachians. In fall, southbound birds feed at various heights in shrubs and trees, and they appear most frequently east of the Appalachians. Tennessee warblers spend the winter from southern Mexico to northwestern South America. They pass through the South during migration, and, depending upon location and season, can be easy—or hard—to find.
Legendary ornithologist Alexander Wilson first described and named the Tennessee warbler after collecting one on the shore of the Cumberland River in Tennessee. He must have thought this bird was not a nester because the scientific name he gave it means, roughly, “the wandering worm-eater.” Wilson thought the bird was rare, but we now know that it is a widespread, common nester in a variety of woodlands across northern North America, mostly in Canada.