SCIENTIFIC NAME: Setophaga pensylvanica
The Chestnut-sided Warbler is a moderately-sized New World warbler. It is a slender, yellow-capped and chestnut-flanked songbirds that is very active and often seen foraging quite low in the foliage.
Both sexes measure about 4.7 -5.5 inches in length, with a wingspan of 7.5 - 8.3 inches and weight of 10.7 - 14.3 grams.
Winter plumage is unstreaked lime green on crown and upperparts (adult males may show weak dark streaks on crown and mantle), contrasting with grayish-white ear-coverts and entire underparts, and with blackish wings, the latter with two bold yellowish-white bars. A white eye ring may be noticeable. Dark tail shows whitish patches, and bill and legs are blackish.
Summer plumage is totally different, with heavily streaked upperparts, yellowish crown, blackish crown sides and malar stripe, rich chestnut flanks (most extensive in males), and whitish remainder of underparts and sides of head.
Both sexes are similar, but the females are duller in breeding plumage. In winter, females lack chestnut on the sides.
Immatures resemble fall adults, with fine streaks on back and lime green above.
CALL: A sharp “chip”, slightly softer than the call of Yellow warbler.
SONG: Loud, clear, somewhat variable whistling, sometimes rendered “pleased-pleased-pleased-to-meetcha”, usually accented at the end.
Young birds learn the song from the adults.
Feeds primarily on insects, a lot of small flies and larvae of butterflies and moths. It may also eat other small invertebrates like spiders.
They eat some fruit and seeds in winter.
Breeds in bushy undergrowth, thickets and areas of small trees, especially favoring woodland edges, second grows, cleared deciduous woodland and abandoned fields or pastures.
Winters in moist tropical forest.
Breeds from Central Saskatchewan, eastward to Nova Scotia, southward to N Minnesota, S Pennsylvania, and S in Appalachians to N Georgia.
Winters in Central America, from S Mexico to Panama.
The nest is built by the female alone, in deciduous tree or shrub.
It is a loosely woven cup made of bark stripes, weed stems, grasses, plant down, sedges and rootlets.
The female lays 4 white eggs, spotted with brown.
Incubation lasts about 11 to 12 days, by female too.