The Mangrove Yellow Warbler (Setophaga petechia erithachorides) and Tennessee Warbler (Leiothlypis peregrina) are small, active insect-eating songbirds commonly seen in Costa Rica, especially during migration and the non-breeding season. Both forage among foliage, often catching insects and occasionally eating nectar or fruit. However, the Mangrove Yellow Warbler is a year-round resident of mangroves and coastal wetlands, with brilliant yellow plumage and a chestnut head in males. The Tennessee Warbler is a migratory visitor from North America, favoring forests and gardens. It has olive-green upperparts, whitish underparts, and a plain face with a fine, pointed bill.

红树林黄莺（Setophaga petechia erithachorides）和田纳西莺（Leiothlypis peregrina）都是体型小巧、活跃的食虫鸣禽，在哥斯达黎加十分常见，尤其是在候鸟迁徙和越冬季节。两者都喜欢在树叶间觅食，以昆虫为主，也会偶尔取食花蜜和浆果。

不过，两者在栖息环境和生活史上有明显差异。红树林黄莺是哥斯达黎加的留鸟，全年栖息于红树林和沿海湿地，雄鸟全身羽色鲜黄色，头部呈栗红色，十分醒目。田纳西莺则是来自北美的迁徙候鸟，主要出现在森林、林缘和花园等环境，体背橄榄绿色，腹部灰白，面部花纹简单，嘴细而尖，整体色彩较为低调。

Mangrove Yellow Warbler 红树林黄色林莺

Tennessee Warbler 灰冠虫森莺