Scientific Name: Setophaga pensylvanica

Breeding birds show a yellow cap, a black triangle under the eye, a streaked back, and reddish-brown sides. They look remarkably different in fall, with a distinctive lime-green color above, gray below, and a bold white eyering. Chestnut-sided Warblers breed mainly in secondary forests, especially in areas with large shrubs and young trees. They do well in disturbed habitats, particularly power line cuts and areas that have been logged. They forage for insects and spend the winter in Central America.

During migration and winter, this small, active warbler can be seen moving quickly through vegetation as it searches for food. In Costa Rica, it is most often found in brushy areas, forest edges, gardens, and regenerating habitats where there is plenty of cover. Its bright colors and energetic movements make it a special bird to notice, especially for birdwatchers exploring areas rich in tropical biodiversity.