Hey guys, welcome back! Today’s little bird is another from the warbler family. To see a chestnut-sided warbler in the spring, you’ll understand just how it got its name. They are black and white above, with a yellow cap, white below, with a black mask and line of chestnut-brown along its side. There’s really no other bird that looks like it, making it one of the easier warblers to ID. But to see one in fall is an entirely different story. In fall there are more juvenile birds migrating, and since they have the same plumage as an adult female, you typically see more birds in this drabber plumage. These birds lack any chestnut sides and are a more of a lime green above and gray and white below. They lack the black mask, but do sport a distinct white eye-ring. Even non-breeding males lack the black mask, though they typically have at least some brown on their sides.
The chestnut-sided warbler is one of the few birds that have thrived thanks to human development. They prefer new growth forests, and scrubby forest edges. Their populations have skyrocketed in the last 150 years or so, and it’s believed that a major contributor to that is us! Cutting down forests and building housing developments creates much more scrubby forest edges and new growth forests, which has benefitted these guys since that is their preferred habitat. They are now one of the more common migrating warblers in the eastern US.
Typically, because of their love of new growth, these guys are easy to spot, often foraging at or near eye level. I do remember the first time I saw one in fall. Thought it was a completely different bird! Somehow it clicked though and after staring at it for a few minutes, I remembered what it was! From one aptly named warbler to another, join me next time when we look at the yellow-throated warbler. See you all then!