Measuring 10 to 14 cm(3.9 to 5.5 in) long and wingspan 16 to 21 cm (6.3 to 8.3 in)with body mass ranging from 8 to 13.1 g , it is a moderately sized bird. In summer male Chestnut-sided Warblers display dark-streaked gray backs, white faces, black eyestripes and greenish crowns. They have two white wing bars, underparts are also white with chestnut flanks.The adult females resemble washed-out versions of the summer male, and in particular, the females lack the strong head pattern.Non-breeding birds of both sexes have greenish heads, and greenish unstreaked upperparts.


Habitat and Distribution

The Chestnut-sided Warblers breed in eastern North America and in southern Canada westwards to the Canadian Prairies. They also breed in the Great Lakes region and in the eastern USA. These birds are migratory, wintering in Central America south to northern Colombia and also Ecuador. They are very rare vagrants to western Europe and arrive in their breeding range in May departing by mid September.


Feeding

They are insectivorous, foraging actively in shrubs and small trees and sometimes catch insects in mid air. Berries(especially those of Cymbopetalum mayanum) are included in the diet during winter.


Breeding

They make cup-shaped nests which are placed in a low bush, which is usually located in young deciduous woodland or scrub. These birds lay 3 to 5 eggs that are creamy white or greenish with brown speckles in color. The nest is a small cup woven of bark strips, weed stems,and grasses. The nest is usually placed in a shrub or vertical tangle of vines no more than 2 m above the ground.


Calls and Songs

Their calls are harsh chips. The songs are high whistled lines described as pleased, pleased, pleased to MEECHA sung by the male.