They are strongly built, with stouter legs and a slightly thicker bill than many other warblers. The plumage is in varying shades of grey and brown, usually darker above and paler below, with bluish or pinkish tones in several species; several also have orange-brown or rufous fringed wing feathers. The tail is square-ended in most, slightly rounded in a few, and in several species has white sides. Many of the species show some sexual dimorphism, with distinctive male and female plumages, with the males in many having black or bright grey on the heads, replaced by brown, brownish-grey or similar dusky colours in females; about a third of the species also have a conspicuous red eye ring in males. Species breeding in cool temperate regions are strongly migratory, while most of those in warmer regions are partially migratory or resident. They are active warblers usually associated with open woodland, scrub, hedges or shrubs. Their diet is largely insectivorous, though several species also eat fruit extensively, mainly small berries such as elder and ivy, particularly from late summer to late winter; one species (blackcap) also frequently takes a wide variety of human-provided foods on birdtables in winter.[2][5]
The typical warblers are now known to form a major lineage in a clade containing also the parrotbills and some taxa formerly considered to be Old World babblers.[10][11] The other "Old World warblers" have been moved to their own families, entirely redelimiting the Sylviidae.[12]
^Helbig, A. J. (2001). The characteristics of the genus: Phylogeny and biogeography of the genus Sylvia. Pages 24–28 in: Shirihai, H., Gargallo, G., Helbig, A. J., & Harris, A. Sylvia Warblers. Helm Identification Guides ISBN0-7136-3984-9
^Snow, D. W., & Perrins, C. M. (1998). The Birds of the Western Palearctic (Concise ed.). Oxford: Oxford University Press. ISBN0-19-854099-X.{{cite book}}: CS1 maint: multiple names: authors list (link)
^Alström, P.; Ericson, P. G. P.; Olsson, U.; Sundberg, P. (2006). "Phylogeny and classification of the avian superfamily Sylvioidea". Molecular Phylogenetics and Evolution. 38 (2): 381–397. doi:10.1016/j.ympev.2005.05.015. PMID16054402.