Trying to identify warblers can be fun. There are more than 20 that you can see at the PGT. Many are colorful like butterflies.
A few of them; like the Tennessee Warbler that I photographed this morning are quite drab. One critical tip to help identify them is to learn their songs.
Warblers have very thin sharp bills that they use to grab insects. Here the bird was working over the leaves to find small bugs to eat. This type of feeding is called gleaning.