How to Identify a Chestnut-Sided Warbler

Updated: Mar. 22, 2024

See what a male and female chestnut-sided warbler looks like, and learn where to find the birds, what they eat, and what they sound like.

Chestnut-Sided Warbler Identification

chestnut sided warbler, how to prevent window strikesRob Ripma
Male chestnut-sided warbler

A tiny, fast-moving warbler is always a challenge for birders to identify. Look for chestnut streaks on the bird’s sides to know for sure whether you’ve spotted a chestnut-sided warbler. Males have a bright yellow cap and black streaks over the eyes; wings have yellow accents.

Females have similar plumage to males, although diluted. They can lack the male’s chestnut accents, and streaks over the eyes appear grayish rather than bold black.

Female Chestnut-sided Warbler in Spring - Ontario, CanadaBrianLasenby/Getty Images
Female chestnut-sided warbler in Ontario, Canada

During nonbreeding season, males adopt a slightly different plumage. They lose their black eye streaks and gain a white ring around the eyes, and the chestnut sides take on a lighter, streaky quality.

For another clue to help identify these warblers, watch their tails.

“One of the fun things about them, which I learned in Costa Rica, is that of all warblers, they hold their tails up the most,” says Dr. Kevin J. McGowan, senior course developer for the Cornell Lab of Ornithology’s Bird Academy. “You’re so used to the yellow crown and the chestnut sides, and the female being that yellowish green, but if you think about it—yeah, they do. They keep their tail up more than other warblers do, for sure.”

Learn how to identify and attract a yellow-rumped warbler.

Range and Habitat

chestnut-sided warblerCourtesy Jocelyn Anderson
Look for a small bird with a yellow cap, black eye streaks and brown sides.

As is the case with many warblers, the chestnut-sided warbler flies through much of the eastern half of the United States during its spring and fall migration journeys. It spends the breeding season in the northern United States and Canada (with a section of its range extending through West Virginia).

Chestnut-sided warblers usually stay in new-growth forests recovering from damage of some kind (logging, fire, or storms). When a habitat becomes too “grown over,” they’ll move on to another regenerating habitat.

“They’re in second-growth, so not mature forests,” Kevin says. “When you get into a solid, closed-canopy forest, they drop out. They do tend to be in more open areas, which does make them easier to spot.”

Discover fascinating facts about warblers that will make you love them even more.

What Does a Chestnut-Sided Warbler Eat?

chestnut sided warblerCourtesy Evelyn Johnson
These bug-eating birds do not visit backyard feeders.

Chestnut-sided warblers eat a typical warbler diet: which is to say, they mostly eat bugs. They’ll dine on caterpillars and fly larvae, as well as moths, beetles, and other flying insects that they dart out to catch in midair. They’ll also find bugs on the undersides of leaves as they hop through shrubs and trees.

Because they don’t eat seed, it’s unlikely one would visit a feeder; however, it might stop by a bird bath.

These pictures of warblers will make you want to go birding.

Nest and Eggs

09 Jimknox Bbxjuly19Courtesy Jim Knox
Juvenile chestnut-sided warbler

Females build a cup-style nest low to the ground, in shrubs or deciduous trees. They typically lay four eggs, although they can lay as few as three or as many as five, and they’ll have up to two broods per season.

The female incubates the eggs for about a week and a half, and after another week and a half after hatching, the young are ready to leave the nest.

Here’s how to attract prothonotary warblers to your birdhouses.

Chestnut-Sided Warbler Song

chestnut-sided warblerCourtesy Jan Olsommer
Chestnut-sided warbler singing

Some birders describe the lyrics of this eastern migrant’s song as pleased to meetcha.

Next, learn all about black-and-white warblers.

About the Expert

Lifelong birder and ornithologist Dr. Kevin McGowan is a senior course developer for the Cornell Lab of Ornithology’s Bird Academy. He earned a Ph.D in biology at the University of South Florida.


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