The "Old World Warblers", family Sylviidae are a family of small passerine bird species; the names sylviid warblers or true warblers may be more appropriate. The Sylviidae mainly occur as breeding species, as the name implies, in Europe, Asia and, to a lesser extent Africa. However, most birds of temperate regions are strongly migratory, and winter in the latter continent or tropical Asia. Many are accomplished songbirds, though perhaps not as much as other warblers or some thrushes.

The American wood warblers (Parulidae), the Olive Warbler (Peucedramidae) and the stenostirid warblers or "flycatcher tits" (Stenostiridae) are not closely related to the sylviids. The Australian warblers (Acanthizidae), apart from also being Passeri, are entirely unrelated.

Characteristics

Most Old World Warblers are of generally undistinguished appearance, though some Asian species are boldly marked. The sexes are often identical, but may be clearly distinct, notably in the genus Sylvia. They are of small to medium size, varying from 9 to 16 centimetres in length, with a small, finely pointed bill. Almost all species are primarily insectivorous, although some will also eat fruit, nectar, or tiny seeds.

The majority of species are monogamous and build simple, cup-shaped nests in dense vegetation. They lay between two and six eggs per clutch, depending on species. Both parents typically help in raising the young, which are able to fly at around two weeks of age.

Systematics

In the late 20th century, the Sylviidae were thought to unite nearly 300 small insectivorous bird species in nearly 50 genera. They had themselves been split out of the Muscicapidae. The latter family had for most of its existence served as perhaps the ultimate wastebin taxon on the history of ornithology. By the early 20th century, about every insectivorous Old World "songster" known to science had at one point been placed therein, and most continued to do so.

Only after the mid-20th century did the dismantling of the "pan-Muscicapidae" begin in earnest. However, the Sylvidae remained a huge family, with few clear patterns of relationships recognisable. Though by no means as diverse as the Timaliidae (Old World babblers) (another "wastebin taxon" containing more thrush-like forms), the frontiers between the former "pan-Muscicapidae" were much blurred. The largely southern warbler family Cisticolidae was traditionally included in the Sylviidae. The kinglets, a small genus in a monotypic family Regulidae, were also frequently placed in this family. The American Ornithologists' Union includes the gnatcatchers, as subfamily Polioptilinae, in the Sylviidae.

Sibley & Ahlquist (1990) united the "Old World warblers" with the babblers and other taxa in a superfamily Sylvioidea as a result of DNA-DNA hybridisation studies. This demonstrated that the Muscicapidae as initially defined were a form taxon which collected entirely unrelated songbirds. Consequently, the monophyly of the individual "songster" lineages themselves was increasingly being questioned.

More recently, analysis of DNA sequence data has provided information on the Sylvioidea. Usually, the scope of the clade was vastly underestimated and only one or two specimens were sampled for each presumed "family". Minor or little-known groups such as the parrotbills were left out entirely (e.g. Ericson & Johansson 2003, Barker et al. 2004). These could only confirm that the Cisticolidae were indeed distinct, and suggested that bulbuls (Pycnonotidae) were apparently the closest relatives of a group containing Sylviidae, Timaliidae, cisticolids and white-eyes.

In 2003, a study of Timaliidae relationships (Cibois 2003a) using mtDNA cytochrome b and 12S/16S rRNA data indicated that the Sylviidae and Old World babblers were not reciprocally monophyletic to each other. Moreover, Sylvia, the type genus of the Sylvidae, turned out to be closer to taxa such as the Yellow-eyed Babbler (Chrysomma sinense) (traditionally held to be an atypical timaliid) and the Wrentit (Chamaea fasciata), an enigmatic species generally held to be the only American Old World babbler. The parrotbills, formerly considered a family Paradoxornithidae (roughly, "puzzling birds") of unclear affiliations also were part of what apparently was a well distinctive clade.

Cibois suggested that the Sylviidae should officially be suppressed by the ICZN as a taxon and the genus Sylvia merged into the Timaliidae (Cibois 2003b), but doubts remained. Clearly, the sheer extent of the groups concerned made it necessary to study a wide range of taxa. This was begun by Beresford et al. (2005) and Alström et al. (2006). They determined that the late-20th-century Sylviidae united at least 4, but probably as much as major 7 distinct lineages. The authors propose the creation of several new families (Phylloscopidae, Cettiidae, Acrocephalidae, Megaluridae) to better reflect the evolutionary history of the sylvioid group.

The Sylviidae, in turn, receive several taxa from other families. Nonetheless, the now-monophyletic family has shrunk by nearly 80% for the time being, now containing 55 species in 10 genera at least. It is entirely likely however that with further research, other taxa from those still incertae sedis among its former contents, the Timaliidae, the Cisticolinae, or even the Muscicapidae will be moved into this group.

Species

Family Sylviidae sensu stricto

True warblers (or sylviid warblers) and parrotbills. A fairly diverse group of smallish taxa with longish tails. Mostly in Asia, to a lesser extent in Africa. A few range into Europe; one monotypic genus on west coast of North America.

• Genus Sylvia - typical warblers (c.20 species). Paraphyletic or contains Parisoma
  • Temperate Eurasian superspecies ("atricapilla-borin group")
    • Blackcap, Sylvia atricapilla
    • Garden Warbler, Sylvia borin
  • Parisoma superspecies
    • Banded Warbler, Parisoma boehmi
    • Layard's Warbler, Parisoma layardi
    • Rufous-vented Warbler, Parisoma subcaeruleum
  • curruca clade
    • Brown Warbler, Parisoma lugens
    • Yemen Warbler, Sylvia buryi - sometimes placed in Parisoma
    • Red Sea Warbler, Sylvia leucomelaena
    • (Western) Orphean Warbler, Sylvia hortensis
      • Eastern Orphean Warbler, Sylvia (hortensis) crassirostris
    • Lesser Whitethroat, Sylvia curruca
    • Hume's Whitethroat, Sylvia althaea
    • Small Whitethroat, Sylvia minula
      • Margelanic Whitethroat, Sylvia (minula) margelanica
  • communis-melanocephala assemblage
    • Barred Warbler, Sylvia nisoria - tentatively place here
    • Asian Desert Warbler, Sylvia nana
    • African Desert Warbler, Sylvia deserti
    • Whitethroat, Sylvia communis
    • Spectacled Warbler, Sylvia conspicillata
    • Tristram's Warbler, Sylvia deserticola
    • Dartford Warbler, Sylvia undata
    • Marmora's Warbler, Sylvia sarda
      • Balearic Warbler, Sylvia (sarda) balearica
    • Rüppell's Warbler, Sylvia rueppelli
    • Cyprus Warbler, Sylvia melanothorax
    • (Western) Subalpine Warbler, Sylvia cantillans
      • Eastern Subalpine Warbler, Sylvia (cantillans) albistriata
      • Moltoni's Warbler, Sylvia (cantillans) moltonii
    • Sardinian Warbler, Sylvia melanocephala
      • Sylvia (melanocephala) momus
      • Fayyum Warbler, Sylvia melanocephala/momus norissae - doubtfully distinct, extinct (c.1940)
    • Menetries' Warbler, Sylvia mystacea

Chrysomma sinense, the Yellow-eyed "Babbler", is a sylviid closely related to parrotbills

• Genus Pseudoalcippe - African Hillbabbler. Formerly in Illadopsis (Timaliidae)
• Genus Rhopophilus - White-browed Chinese Warbler. Formerly in Cisticolidae
• Genus Lioparus - Golden-breasted Fulvetta. Formerly in Alcippe (Timaliidae)
• Genus Paradoxornis - typical parrotbills (18 species). Formerly in Paradoxornithidae; polyphyletic
• Genus Conostoma - Great Parrotbill. Formerly in Paradoxornithidae; tentatively placed here
• Genus Fulvetta - typical fulvettas (7 species). Formerly in Alcippe (Timaliidae)
• Genus Chrysomma - 3 species. Formerly in Timaliidae
• Genus Chamaea - Wrentit

Moved to family Timaliidae

• Genus Graminicola
  • Rufous-rumped Grassbird ("-babbler") Graminicola bengalensis

Moved to family Cisticolidae

• Genus Bathmocercus - rufous-warblers
  • Black-capped Rufous-warbler Bathmocercus cerviniventris
  • Black-faced Rufous-warbler Bathmocercus rufus
• Genus Sceptomycter - sometimes merged into Bathmocercus. Cisticolidae?
  • Mrs Moreau's Warbler Sceptomycter winifredae
• Genus Poliolais - Cisticolidae or more basal like bulbuls?
  • White-tailed Warbler Poliolais lopezi
• Two to 14 of the 15 tailorbirds

Moved to family Acrocephalidae Icterine Warbler, Hippolais icterina

Marsh- and tree warblers or acrocephalid warblers. Usually rather large "warblers", most are olivaceous brown above with much yellow to beige below. Usually in open woodland, reedbeds or tall grass. Mainly southern Asia to western Europe and surroundings ranging far into Pacific, some in Africa. The genus limits are seriously in need of revision; either most species are moved into Acrocephalus, or the latter is split up though there is presently insufficient knowledge as to how.

• Genus Acrocephalus - marsh-warblers (about 35 species)
• Genus Hippolais - tree warblers (8 species)
• Genus Chloropeta - yellow warblers
  • Yellow Flycatcher-warbler Chloropeta natalensis
  • Mountain Flycatcher-warbler Chloropeta similis
  • Papyrus Flycatcher-warbler Chloropeta gracilirostris

Moved to Malagasy warblers

See Cibois et al. (2001)

• Genus Thamnornis
  • Thamnornis Thamnornis chloropetoides
• Genus Cryptosylvicola
  • Cryptic Warbler Cryptosylvicola randriansoloi

Moved to family Megaluridae New Zealand's K?t?t? or M?t?t?, the Fernbird, probably belongs to the Megaluridae

Grass warblers and allies or megalurid warblers. Mid-sized and usually long-tailed species; sometimes strongly patterned but generally very drab in overall coloration. Often forage on the ground. Old World and into Australian region, centred around Indian Ocean; possibly also one species in South America. A not too robustly supported clade that requires further study.

• Genus Bradypterus - Megalurid bush-warblers (more than 20 species). Paraphyletic with at least one species ("B." victorini) not belonging into this family.
• Genus Locustella - grass warblers (9 species)
• Genus Megalurus - typical grassbirds. Probably polyphyletic
  • Marsh Grassbird Megalurus pryeri
  • Tawny Grassbird Megalurus timoriensis
  • Little Grassbird Megalurus gramineus
  • Striated Grassbird Megalurus palustris
  • Fly River Grassbird Megalurus albolimbatus
  • The Black-capped Donacobius Donacobius atricapillus which was long considered an aberrant wren might constitute the only American species of this family.

Moved to family Cettiidae

Typical bush warblers and relatives or cettiid warblers. Another group of generally very drab species, tend to be smaller and shorter-tailed than Megaluridae. Usually frequent shrubland and undergrowth. Continental Asia, and surrounding regions, ranging into Africa and southern Europe.

• Genus Pholidornis - formerly in Remizidae; tentatively placed here
  • Tit-hylia Pholidornis rushiae
• Genus Hylia - tentatively placed here
  • Green Hylia Hylia prasina
• Genus Abroscopus - Abroscopus warblers
  • Rufous-faced Warbler Abroscopus albogularis
  • Yellow-bellied Warbler Abroscopus superciliaris
  • Black-faced Warbler Abroscopus schisticeps

Uguisu (?), the Japanese Bush-warbler (Cettia diphone). See also uguisubari.

• Genus Erythrocercus - monarch-warblers. Formerly Monarchinae.
  • Chestnut-capped Flycatcher Erythrocercus mccallii
  • Yellow Flycatcher Erythrocercus holochlorus
  • Livingstone's Flycatcher Erythrocercus livingstonei
• Genus Urosphena - stubtails
  • Timor Stubtail Urosphena subulata
    • Babar Stubtail Urosphena subulata advena - extinct (mid-20th century)
  • Bornean Stubtail Urosphena whiteheadi
  • Asian Stubtail Urosphena squameiceps
• Genus Tesia - tesias
  • Chestnut-headed Tesia Tesia castaneocoronata
  • Javan Tesia Tesia superciliaris
  • Slaty-bellied Tesia Tesia olivea
  • Grey-bellied Tesia Tesia cyaniventer
  • Russet-capped Tesia Tesia everetti
• Genus Cettia - typical bush-warblers (some 15 species). Polyphyletic.
• Genus Tickellia
  • Broad-billed Warbler Tickellia hodgsoni
• Genus Phyllergates
  • Mountain Tailorbird Phyllergates cucullatus
  • Rufous-headed Tailorbird Phyllergates heterolaemus

Moved to Family Aegithalidae

• Genus Leptopoecile - tit-warblers. Tentatively placed there.
  • White-browed Tit-warbler Leptopoecile sophiae
  • Crested Tit-warbler Leptopoecile elegans

Moved to family Phylloscopidae

Leaf-warblers or phylloscopid warblers. A group very variable in size, often vivid green coloration above and yellow below, or more subdued with greyish-green to greyish-brown plumage. Catch food on the wing fairly often. Eurasia, ranging into Wallacea and Africa.

Wood Warbler Phylloscopus sibilatrix

• Genus Phylloscopus - leaf-warblers (c.55 species). Polyphyletic.
• Genus Seicercus - polyphyletic
  • Golden-spectacled Warbler Seicercus burkii
    • Grey-crowned Warbler Seicercus (burkii) tephrocephalus
    • Whistler's Warbler Seicercus (burkii) whistleri
    • Bianchi's Warbler Seicercus (burkii) valentini
  • Emei Shan Warbler Seicercus omeiensis
  • Plain-tailed Warbler Seicercus soror
  • White-spectacled Warbler Seicercus affinis - paraphyletic
    • Bar-winged White-spectacled Warbler Seicercus (affinis) intermedius
  • Grey-cheeked Warbler Seicercus poliogenys
  • Grey-hooded Warbler Seicercus xanthoschistos
  • Chestnut-crowned Warbler Seicercus castaniceps
  • Yellow-breasted Warbler Seicercus montis
  • Sunda Warbler Seicercus grammiceps

"African Warblers"

Also "Sphenoeacus group". An assemblage of usually species-poor and apparently rather ancient "odd warblers" from Africa. Ecomorphologically quite variable. Monophyly requires confirmation.

• Genus Sylvietta - crombecs
  • Green Crombec Sylvietta virens
  • Lemon-bellied Crombec Sylvietta denti
  • White-browed Crombec Sylvietta leucophrys
    • Chapin's Crombec Sylvietta (leucophrys) chapini - possibly extinct (late 20th century?)
  • Northern Crombec Sylvietta brachyura
  • Short-billed Crombec Sylvietta philippae
  • Red-capped Crombec Sylvietta ruficapilla
  • Red-faced Crombec Sylvietta whytii
  • Somali Crombec Sylvietta isabellina
  • Cape Crombec Sylvietta rufescens
• Genus Melocichla
  • Moustached Grass-warbler Melocichla mentalis
• Genus Achaetops
  • Damara Rock-jumper Achaetops pycnopygius
• Genus Sphenoeacus
  • Cape Grassbird Sphenoeacus afer
• Genus N.N. - formerly Bradypterus (now Megaluridae)
  • Victorin's Scrub-warbler "Bradypterus" victorini
• Genus Macrosphenus - longbills
  • Kemp's Longbill Macrosphenus kempi
  • Yellow Longbill Macrosphenus flavicans
  • Grey Longbill Macrosphenus concolor
  • Pulitzer's Longbill Macrosphenus pulitzeri
  • Kretschmer's Longbill Macrosphenus kretschmeri

"Sylviidae" incertae sedis

Taxa that have not been studied. Most are likely to belong to one of Sylvioidea families listed above. Those in the Australian-Pacific region are probably Megaluridae. These taxa are listed in the sequence used in recent years.

• Genus Dromaeocercus - emu-tails. Megaluridae?
  • Brown Emu-tail Dromaeocercus brunneus
  • Grey Emu-tail Dromaeocercus seebohmi - sometimes separated in Amphilais

• Genus Nesillas - brush warblers. Malagasy warblers?
  • Aldabra Brush-warbler Nesillas aldabrana - extinct (c.1984)
  • Anjouan Brush-warbler Nesillas longicaudata
  • Madagascar Brush-warbler Nesillas typica
  • Grand Comoro Brush-warbler Nesillas brevicaudata
  • Moheli Brush-warbler Nesillas mariae

• Genus Phyllolais - Cisticolidae?
  • Buff-bellied Warbler Phyllolais pulchella

• Genus Graueria
  • Grauer's Warbler Graueria vittata

• Genus Eremomela - eremomelas. Cettiidae?
  • Salvadori's Eremomela Eremomela salvadorii
  • Yellow-vented Eremomela Eremomela flavicrissalis
  • Yellow-bellied Eremomela Eremomela icteropygialis
  • Senegal Eremomela Eremomela canescens
  • Green-backed Eremomela Eremomela pusilla
  • Greencap Eremomela Eremomela scotops
  • Yellow-rumped Eremomela Eremomela gregalis
  • Rufous-crowned Eremomela Eremomela badiceps
  • Turner's Eremomela Eremomela turneri
    • Western Turner's Eremomela Eremomela turneri kalindei - probably extinct (early 1980s?)
  • Black-necked Eremomela Eremomela atricollis
  • Burnt-neck Eremomela Eremomela usticollis

• Genus Randia - Malagasy warblers?
  • Rand's Warbler Randia pseudozosterops

• Genus Hemitesia
  • Neumann's Warbler Hemitesia neumanni

• Genus Bowdleria - fernbirds. Sometimes merged into Megalurus. Megaluridae?
  • Fernbird Bowdleria punctata
  • Chatham Islands Fernbird Bowdleria rufescens - extinct (c.1900)

• Genus Chaetornis - Bristled Grassbird. Megaluridae?

• Genus Schoenicola - grassbirds. Basal Megaluridae?
  • Broad-tailed Grassbird Schoenicola platyura
  • Fan-tailed Grassbird Schoenicola brevirostris

• Genus Cincloramphus - songlarks. Basal Megaluridae?
  • Brown Songlark Cincloramphus cruralis
  • Rufous Songlark Cincloramphus mathewsi

• Genus Eremiornis - probably Megaluridae
  • Spinifex-bird Eremiornis carteri

• Genus Buettikoferella - probably Megaluridae
  • Buff-banded Bushbird Buettikoferella bivittata

• Genus Megalurulus - thicketbirds. Probably Megaluridae
  • New Caledonian Grassbird Megalurulus mariei
  • Bismarck Thicketbird Megalurulus grosvenori
  • Bougainville Thicketbird Megalurulus llaneae
  • Guadalcanal Thicketbird Megalurulus whitneyi
  • Rusty Thicketbird Megalurulus rubiginosus

• Genus Trichocichla - Long-legged Warbler

Not in Sylvioidea

Entirely unrelated songbirds hitherto placed in Sylviidae

• Genus Amaurocichla - Apparently a Passeroidea; very close to, or part of the Motacillidae
  • Bocage's Longbill or São Tomé Short-tail Amaurocichla bocagei
• Genus Stenostira - Together with some "odd flycatchers", they form the new family Stenostiridae. They are closely related to Paridae (Beresford et al. 2005)
  • Fairy Warbler Stenostira scita
• Genus Hyliota - hyliotas. Basal Passerida with no known relatives, perhaps somewhat closer to Promeropidae (sugarbirds)
  • Yellow-bellied Hyliota Hyliota flavigaster
  • Southern Hyliota Hyliota australis
  • Usambara Hyliota Hyliota usambarae
  • Violet-backed Hyliota Hyliota violacea
• Genus Newtonia - newtonias. Now in Vangidae (vangas); possibly polyphyletic (Yamagishi et al. 2001)
  • Dark Newtonia Newtonia amphichroa
  • Common Newtonia Newtonia brunneicauda
  • Archbold's Newtonia Newtonia archboldi
  • Red-tailed Newtonia Newtonia fanovanae - tentatively placed here