warbler, any of various species of small songbirds belonging predominantly to the Sylviidae (sometimes considered a subfamily, Sylviinae, of the family Muscicapidae), Parulidae, and Peucedramidae families of the order Passeriformes. Warblers are small, active insect eaters found in gardens, woodlands, and marshes.

Yellow-rumped Warblers have two main calls. The more common one, a sharp chek, differs between the myrtle and Audubon's races. Learning the songs of warblers can be a great help in locating and identifying them during the spring. Many skilled birders identify warblers by song before they see the singer, and sometimes, they hear warblers without seeing them.