This article is about the birds. For the two ships, see USS Warbler. For the singing group from the TV show "Glee", see Glee: The Music Presents the Warblers.
There are a number of Passeriformes (perching birds) called warblers. They are not necessarily closely related to one another, but share some characteristics, such as being fairly small, vocal, and insectivorous.
They are mostly brownish or dull greenish in color. They tend to be more easily heard than seen. Identification can be difficult and may be made on the basis of song alone. To English-speaking Europeans, warblers are the archetypal "LBJs" (little brown jobs).
1 Sylvioid warblers,
2 Passeroid warblers,
These are somewhat more closely related to each other than to other warblers. They belong to a superfamily also containing Old World babblers, bulbuls, etc.
"Old World warblers", formerly all in family Sylviidae
Leaf warblers, now in family Phylloscopidae,
Typical bush warblers, now in family Cettiidae,
Grass warblers and megalurid bush-warblers, now in family Locustellidae,
Marsh and tree warblers, now in family Acrocephalidae,
True warblers or sylviid warblers, remaining in family Sylviidae or moved into the Timaliidae,
Malagasy warblers, the newly assembled family Bernieridae,
Cisticolid warblers, family Cisticolidae,
"African warblers", possibly another novel family,
The two families of American warblers are part of another superfamily, which unites them with sparrows, buntings, finches, etc.
Olive Warbler, monotypic family Peucedramidae,
New World warblers, family Parulidae,
Tit-warblers or flycatcher-tits, family Stenostiridae,
These are closely related to the titmice and chickadees
Australasian warblers, family Acanthizidae,
These are the most distinct group of warblers. They are not closely related at all to the others, but rather to the honeyeaters and fairy-wrens.
Hawaiian honeycreeper--Warbler-niched-(adaptive radiation), genus H. virens-Common Amakihi. (See: List of adaptive radiated honeycreepers)