A medium-sized (4 ½ -5 ½ inches) wood warbler, the male Chestnut-sided Warbler is most easily identified by its pale breast, streaked back, yellow crown, and conspicuous chestnut flanks. Female Chestnut-sided Warblers are similar to males, but are somewhat duller, especially on the flanks. No other wood warbler breeding in North America possesses the combination of chestnut flanks and yellow crown characteristic of this species. The Chestnut-sided Warbler primarily breeds across southern Canada and the northeastern United States. Smaller numbers breed at higher elevations in the Appalachian Mountains as far south as northern Georgia. In winter, the Chestnut-sided Warbler may be found in southern Mexico and Central America. Chestnut-sided Warblers breed in a variety of semi-open deciduous forests, particularly in areas of shrubby growth created by forest fires and other types of ecological disturbance. In winter, this species may be found in and around humid tropical forests. Chestnut-sided Warblers primarily eat small invertebrates, including insects and spiders, although this species may eat some plant material, particularly fruits and berries, during the winter. In appropriate habitat, Chestnut-sided Warblers may be observed foraging for insects underneath leaves in shrubs and lower parts of the canopy. Birdwatchers may also listen for this species’ song, a whistled “please please pleased to meet’cha.” Chestnut-sided Warblers are primarily active during the day, but, like many migratory songbirds, this species migrates at night.
Common but irregular migrant, found in deciduous forests, from late April to late May and mid-August to early October. The male has more chestnut on the side than the female.
A male is in the front, a female in the back.