a web page by Don Roberson |
TREE BABBLERS & SCIMITAR-BABBLERS Timaliidae |
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Even the traditional 'tree babbler' genus Stachyris proved to be paraphyletic, and has been split into at least four genera, with only Stachyris and Stachyridopsis assigned to the Timaliidae. The remainder, all Philippine genera, are now considered related to white-eyes in the Zosteropidae. Stachyris once had 28 species; now it has but 13; Stachyridopsis has six. |
Babblers were once considered a huge family of over 300 species of (mostly) tropical forest birds in the Old World. Studies in the mid-2000s began to clarify the situation (e.g., Cibois 2003, Alström et al. 2006, Jønsson & Fjeldså 2006) but there is uncertainty whether the huge babbler assemblage should be allocated to one or two or more families. Genetic evidence revealed that the Sylvia warblers — the original genus in the 'Old World Warblers' Sylviidae — was more closely related to Babblers than other Old World Warblers [see a discussion of the break-up of the Old World Warblers]. More recent research, especially Gelang et al. (2009), have led to a "break-up of the Babblers." Cibois et al. (2010) summarized the outlines for five babbler families: true babblers and scimitar-babblers [Timaliidae], sylvid babblers and parrotbills [Sylviidae], white-eyes [Zosteropidae], fulvettas and ground-babblers [Pellorneidae], and laughingthrushes [Leiothrichidae]. This approach has been adopted by the 2010 version of the IOC world checklist (Gill et al. 2010), and that approach is adopted here. The five-family solution remains tentative and subject to future research. |
Gelang et al. (2009) also found, based on nuclear and mitochondrial DNA evidence, that babblers evolved within seven significant clades within the two major lineages. One big surprise was that one of a half-dozen genera of wren-babblers — the four species in genus Pnoepygidae — were not within any babbler lineage. They recommended a new family, the Pnoepygidae, for those tiny, short-tailed, "wren-babblers." The remaining genera of birds termed wren-babblers (e.g., Rimator, Ptiolcichla, Kenopia, Napothera, Spelaeornis) are babblers but are assigned to other babbler families, rather than the Timaliidae. In addition:
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All
these changes have left only a 56 species in nine genera among the
Timaliidae. Included is the namesake single species in genus Timalia —
Chestnut-capped Babbler T. pileata of swampy areas from Nepal to China to Java. Six tit-babblers from southeast Asia and the Greater Sundas form genus Macronous; two miniature tit-babblers in the Philippines are assigned to genus Micromacronus, and there are single species in monotypic genera Dumetia (Tawny-bellied Babbler D. hyperythra) and Rhopocichla (Dark-fronted Babbler R. atriceps). |
In
central China, Streak-breasted Scimitar-Babbler P. ruficollis often
occurs in mixed foraging flocks of babblers, parrotbills, and warblers.
Its loud calls are often the first notice one has that a flock is
nearby. Recent discussions have suggested that it be split into several
species. It will take some time for the dust to settle from the
"break-up of the Babblers." |
| Photos: The Rufous-capped Babbler Stachyridopsis ruficeps was photographed in Foping Nature Reserve, Shaanxi, China, on 13 Nov 2010. The Rusty-cheeked Scimitar-Babbler Pomatorhinus erythrogenys was at Sat Tal in the Himalayan foothills of Uttar Pradesh, India, in March 2001. All photos © Don Roberson; all rights reserved. |
Bibliographic notes There is no recent "family book" covering the Babblers but good coverage of four of five of the new babbler families, including the current Timaliidae, is in Collar & Robson (2007). The account is wonderful, with exceptional photos, although it could not have been quite up with the most current taxonomic findings. Literature cited:
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It
has long been an
ornithological joke that the Timaliidae was the "dust-bin" for Old
World birds of uncertain origin: in 1896 Alfred Newman called babbler
taxonomy "a festering mass" (Collar & Robson 2007). That "mess" is
finally being cleaned up. The last word on babbler taxonomy is not yet
in, but a tentative solution has been proposed. And if that solution
holds, the tree babblers in genus Stachyris and Stachyridopsis are among the few "true" babblers assigned to family Timaliidae. One of those is Rufous-capped Babbler (left), a common member of mixed species flocks in Asian mountains from the Himalayas to central China. 
This leaves 15 species of scimitar-babblers in the genus Pomatorhinus round out family Timaliidae. Scimitar-babblers
are undergrowth species and have long decurved bills used to work through the leaf litter —
very like the thrashers of North America which they resemble in
size and body shape. An example is Rusty-cheeked Scimitar-Babbler
(right) of mountain foothills from India to n. Thailand. Like all birds
of shady habitats, it is difficult to snap a photo without a complex
flash set-up but perhaps you can get an idea of this group from this
white-eyed, pale-billed species.