A new analysis of the superfamily Sylvioidea, which includes swallows, larks, bulbuls, long-tailed tits, warblers and white-eyes, has resulted in the creation of three new families.
The relationships of the group have long been the subject of much debate, after the superfamily was confirmed by the work of Sibley and Ahlquist. The traditional Sylviidae – Old World warblers – has been known to consist of several groups which were not each others' closest relatives, and previous work by Alström found divisions great enough to create 10 warbler families, and true Sylvia warblers were found to nest within the babblers Timaliidae.
Now a finer and more comprehensive calibration using a mitcohondrial marker (a single gene associated with a physical or phenotypical trait) along with six nuclear markers from 76 sylvioid species has confirmed further divisions.
While there is still further work to do, three new families are now viewed as supported by the evidence: Scotocercidae (Scrub Warbler from North Africa and the Middle East), Erythrocercidae (the African yellow flycatchers) and Macrosphenidae (the longbills, crombecs and grassbirds, widespread across Africa, Asia and Australasia). There was also tentative support for the creation of the Hyliidae, the hylias and tit-hylias, African species previously included unsatisfactorily in the Cettidae.
A surprising sister relationship was discovered between Bearded Tit (Panuridae) and larks (Alaudidae). The authors also recommend that the tits Paridae, Penduline Tits Remizidae and fairy flycatchers Stenostiridae are kept out of the Sylvioidea. The strange, as yet unassignable, nicators from sub-Saharan Africa remain incertae sedis – of unknown affinity.
Fregin, S, Haase, M, Olsson, U and Alström, P. 2012. New insights into family relationships within the avian superfamily Sylvioidea (Passeriformes) based on seven molecular markers. BMC Evolutionary Biology 12 doi:10.1186/1471-2148-12-157.