Leaf warblers are small insectivorous passerine birds belonging to the genus Phylloscopus.

Its members occur in Eurasia, ranging into Wallacea and Africa with one species, the Arctic Warbler, breeding as far east as Alaska. Many of the species breed at temperate and high latitudes in Eurasia and migrate substantial distances to winter in southeastern Asia, India, or Africa.

The family Phylloscopidae comprises many small tree-loving warbler species and feed by gleaning insects from leaves or catching food on the wing.

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