A taxonomic 'tree' is a visual means of showing relationships between living things. Birds evolved through many eons and are related to each other through an evolutionary tree. Such a visualized 'tree' can be compared to a good old oak tree (right), with the base of the trunk representing avian ancestors, the bigger limbs representing the major evolutionary lineages, the smaller limbs representing subdivisions of those lineages, the branches represented families, the twigs representing genera, and the leaves representing species [more or less].

We "read" a taxonomic tree from the bottom up to trace relationships. Our discussion here centers around the Old World Warblers [Sylviidae], so we will be reading only a part of the avian tree. [More about the 'tree' is on the discussion page of the 'new' tree.] This discussion is about the generalized 'tree' that was thought to illustrate relationship at the turn of the 21st century: Here is the 'tree' and, below that, is a discussion of the families and species illustrated.

This tree of passerine birds is constructed primarily from the approach of the A.O.U. Checklist, 7th ed. (1998), excepting some positions taken by the Handbook of the Birds of the Worlds editors are illustrated as well. It is not 'exactly' anyone's specific tree but represents pretty well what was generally accepted sometimes within the 1990s.

Reading from the bottom up, we see that major branches to the Corvoid and Passeroid groups of birds head off immediately, leaving us with the birds found on the AOU Check-list between Larks and Babblers. There are familiar branches to various families (Swallows, Tits, Long-tailed Tits, Wrens, etc.) but this part of the avian landscape is dominated by a huge assemblage of Old World Warblers [Sylviidae] at the top. The families closest to Old World Warblers were thought to be Thrushes [Turdidae] Bulbuls [Pycnonotidae], Old World Flycatchers [Muscicapidae], Parrotbills [Panuridae], White-eyes [Zosteropidae], and Babblers [Timaliidae].

Each of the photos represents either a 'base' family member or a species (or group of species) that will somehow be impacted or re-arranged by the 'Break-up' of the Sylviidae. The "Break-up of the Sylviidae" impacts that Babblers heavily as well, so the focus is equally on the Timaliidae.

Reading from the bottom up, and generally clockwise, note these species or genera:

  • Black-capped Mockingthrush Donacobius atricapillus, of Amazonian South America, is listed among the Wrens
  • The Bulbuls include two groups of interest: (left) are a set of 5 species of Phyllastrepus greenbuls from Madagascar [Gray-crowned P. cinereiceps is shown]; (right) are two species of Nicator from mainland Africa [Eastern Nicator N. gularis is shown]
  • Among the Old World Flycatchers & Chats are a set of 'flycatchers' from Africa & Asia that include Fairy Flycatcher Stenostira scita (shown), various crested-flycatchers & blue-flycatchers assigned to Elminia or Trochocercus, and two species of canary-flycatcher [Culicicapa] from Asia
  • The Old World Warblers are a huge, speciose group of ~400 species, including, left to right, row to row
    • 15 or so Cettia bush-warblers [Luzon Bush-Warbler C. seebohmi is shown]
    • 68 or so leaf-warblers assigned to the genera Phylloscopus and Seicercus [Tickell's Leaf-Warbler P. affinis is shown]
    • 20 or more grassbirds & allies assigned to the genera Megalurus, Schoenicola, and 3-4 others [Streaked Grassbird M. palustris is shown]
    • About 60 species of Prinia, Apalis, & allies [Black-chested Prinia P. flavicans is shown]
    • 18 species of Sylvia warbler [Sardinian Warbler S. melanocephala is shown]
    • 40+ species of Acrocephalus & Hippolais warblers [Sedge Warbler A. schoenobaenus is shown]
    • 2 species of Leptopoecile tit-warblers in China [White-browed Tit-Warbler L. sophiae is shown]
    • 20+ species of Bradypterus bush-warblers & scrub-warblers [S. Spotted Bush-Warbler B. przevalskii is shown]
    • 14 or so species of Polioptila gnatcatchers & allies [California Gnatcatcher P. californica is shown]
    • 6 species of kinglets, Goldcrest, Flamecrest et al. in genus Regulus [Ruby-crowned Kinglet R. calendula is shown]
    • 9 species of Locustella grasshopper-warblers [Lanceolated Warbler L. lanceolata is shown]
    • 50+ species of cisticolas, genus Cisticola [Red-headed Cisticola C. subruficapillus is shown]
    • 15+ species of Orthotomus tailorbirds [two species shown, L to R: Rufous-tailed Tailorbird O. seiceus & Mountain Tailorbird O. cuculatus]
    • Cape Grassbird Sphenoeacus ater [there are a host of other single-species genera assigned to this family]
    • 3 species of hyliota, genus Hyliota [Yellow-bellied Hyliota H. flavigaster is shown]
    • Thamnornis Warbler T. choropetoides of Madagascar [there are a variety of other Malagasy species, incl. Newtonia, various Jerys Neomixis]
    • 10 or so crombecs in genus Sylvietta [Red-faced Crombec S. whytii is shown]
  • The Parrotbill family [Panuridae] has 18 species of Paradoxornis parrotbills, and the single-species genera Panurus & Conostoma [Spot-breasted Parrotbill P. guttaticollis and Bearded Reedling Panurus biarmicus are shown]
  • The White-eyes [Zosteropidae] include ~75 species of Zosterops white-eyes, plus various allies in other genera [Mountain White-eye Z. montanus is shown]
  • The Babblers [Timaliidae] are a large group of ~235 species, including, L to R, row to row:
    • 50+ species of Garrulax laughing-thrushes [Chestnut-capped Laughingthrush G. miratus is shown]
    • White-bellied Yuhina Erpornis zantholeuca [shown] is assigned to genus Yuhina among 11 other Yuhina
    • 2 species of rockjumper, genus Chaetops, are often placed here, although some put them with Thrushes [Cape Rockjumper C. frenatus is shown]. Some also put 2 species of rockfowl, genus Picathartes, here
    • Wrentit Chamaea fasciata of North America is the only New World babbler
    • many "typical" babblers of various genera make up the bulk of the family [Chestnut-tailed Minla Minla strigula is shown]
    • 3 'babblers' in 3 genera in Madagascar are included [Yellow-browed Oxylabes Crossleyia xanthoprys is shown]; there are a host of other monotypic genera from around the Old World included and not pictured here
It is this host of species that is about to the shaken apart and put back together again. To see how a tentative rearrangement looks, click on the "New Tree" link below.

Click Here
Click Here
Literature cited:
Alström P., P.G.P. Ericson, U. Olsson, and P. Sundberg. 2006. Phylogeny and classification of the avian superfamily Sylvoidea. Molecular Phylogenetics & Evolution 38: 381-397.

Barker, F.K., A. Cibois, P. Schikler, J. Feinstein, and J. Cracraft. 2004. Phylogeny and diversification of the largest avian radiation. Proc. Nat. Acad. Sci. 101: 11040-11045.

Beresford, P., F.K. Barker, P.G. Ryan, and T.M. Crowe. 2005. African endemics span the tree of songbirds (Passeri): molecular systematics of several evolutionary 'enigmas'. Proc. R. Soc. B 272: 849-858.

Cibois, A., E. Pasquet, and T.S. Schulenberg. 1999. Molecular systematics of the Malagasy babblers (Timaliidae) and Warblers (Sylviidae), based on cytochrome b and 16S rRNA sequences. Molecular Phylogenetics & Evolution 3: 581-595.

Cibois, A., B. Slikas, T.S. Schulenberg, and E. Pasquet. 2001. An endemic radiation of Malagasy songbirds is revealed by mitochondrial DNA sequence data. Evolution 55: 1198-1206.

Cibois, A. 2003. Mitochondrial DNA phylogeny of babblers (Timaliidae). Auk 120: 35-54.

Dickinson, E.C., ed. 2003. The Howard & Moore Complete Checklist of the Birds of the World. 3d ed. Princeton Univ. Press, Princeton, N.J.

Jonsson, K.A., and J. Fjeldså. 2006. A phylogenetic supertree of oscine passerine birds. Zoologica Scripta 35: 149-186.

Sibley, C.G., and J.E. Ahlquist. 1990. Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale Univ. Press, New Haven, CT.

Sibley, C. G., and B.L. Monroe, Jr. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT.



Page created 4 June 2006