WARBLER, the general name for all birds of the Passerine families Sylviidae and Mniotiltidae, the Mniotiltidae being un related to the Sylviidae and being confined to the new world. The Sylviidae are small birds with weak, slender bills, feeding on insects and fruit. The song is clear and sweet and often metallic ; the nest is usually cup-shaped, containing from three to six white eggs. Apart from the American kinglets and gnatcatchers (q.v.) the family is confined to the old world. The sedge-warbler (Acro cephalus schoenobaenus) is one of the commonest British species.
It is a small olive-brown bird, with a yellowish eye-streak and a chattering song. It inhabits bushes and reed-beds usually close to water. The nearly allied reed-warbler (A. scirpaceus) lacks the eye-streak and rarely leaves reed-beds; its nest is built between and supported by several reed-stems.
The European great reed-warbler (A. arundinaceus) is larger. The Dartford warbler (Sylvia undata) is one of few warblers resident in Britain, though migratory on the continent. It is locally distributed in the south of England, central Europe and the Mediterranean region. The grasshopper warbler (Locustella naevia) inhabits tangled and thick herbage; its reeling song distinguishes it. The allied Savi's warbler (L. luscinoides) is confined to marshy country and has a higher pitched song. The
icterine warbler (Hypolais icterina) is a straggler to Britain; it has a loud song, and the eggs are brownish pink, spotted with purplish black. The wood warbler or wood-wren (Phylloscopus sibilatrix) haunts woods of oak and beech and has a peculiar loud song. The willow-warbler or willow-wren (P. trochilus) is one of the commonest British species. See also GOLDCREST, WHITETHROAT, WREN, BLACKCAP.
The American or wood warblers are, on the whole, a more brightly coloured group and are distributed throughout North and South America and the Antilles. The yellow warbler (Dendroica aestiva) breeds throughout North America, wintering in South and Central America. The Cerulean warbler (D. cerulea) is less abundant and haunts the tree-tops. The Maryland yellow-throat (Geothlypsis trichas), in which the male has a black mask, is another familiar American form. The oven-bird (Seiurus auroca pillus) is a common woodland species; its song has been described as a crescendo repetition of the word "teacher." The shy water thrush (S. motacilla) possesses a melodious song. The American redstart (q.v.) also belongs to this group.