TREE BABBLERS & SCIMITAR-BABBLERS Timaliidae
- 50 species in Asian tropics
- DR personal total: 19 species (38%), 2 photo'd
the Old World tropics live hundreds of elusive small to mid-sized birds
— babblers! Often first located by sound, many species are elusive in
the shadows and undergrowth, even where they are common, but others are
found among mid-canopy flocks in woodlands. One of those is Rufous-capped Babbler (left), a common member of mixed species flocks in Asian mountains from the Himalayas to central China.
Babblers were once considered a huge family of over 300 species. Studies in the
mid-2000s began to clarify the situation (e.g., Cibois 2003,
Alström et al. 2006, Jønsson & Fjeldså 2006). Genetic evidence revealed that the Sylvia warblers — the original genus in the 'Old World Warblers'
Sylviidae — were more closely related to Babblers than other Old World
Warblers [see a discussion of the break-up of the Old World Warblers].
Additional research, especially Gelang et al. (2009), led to a
"break-up of the Babblers." Cibois et al. (2010) summarized the
outlines for five babbler families: tree babblers and scimitar-babblers
[Timaliidae], sylvid babblers and parrotbills [Sylviidae], white-eyes
[Zosteropidae], fulvettas and ground-babblers [Pellorneidae], and
Moyle et al. (2012) confirmed the major clades in the babbler
assemblage, but recommended that the tree-babblers, laughingthrushes,
and the ground-babblers, be considered subfamilies of an expanded
Babbler family [Timaliidae]. One of the reasons had to do with the
amount of evolutionary time with the other related Families remaining
the Sylvids and the White-eyes. I liked that approach and followed it
for several years, and offered these three clades as subfamilies:
core babblers split from the White-eyes and relatives in the early
Miocene, estimated at 16–21 million years ago (mya; Moyle et al.,
2012). Although that is a long time ago, it is not nearly as old as,
for example, the Family level groups in the broadbill assemblage
[African & Green Broadbills, Asian & Grauer's Broadbills,
Asities, and Sapayoa in the New World] that diverged 45–56 mya (Moyle
et al. 2006). So a Family level at perhaps 20 mya or has not been on
its own evolutionary path as long as many bird families. My feeling is
that something that diverged in early Miocene (about 16-23 mya) is a
good guideline for a minimum of age of what we call a Family. The three
main clades of the core babblers — the tree-babblers &
scimitar-babblers, the laughingthrushes, and the ground-babblers —
began diverging 11.2–17.8 mya (Moyle et al. 2012), so are right at that
border. The main African radiations among babblers are even younger:
the origin of the Illadopsis babblers is 10-14 mya, and the radiation of Turdoides babblers to Africa is 6.4-9.9 mya. These latter divergence times recall those of the ancestor of today's Wrentit Chamaea fasciata of western North America, which began diverging from its parrotbill ancestors about 6.5-8.1 mya (Burns & Barhoum 2006).
puts some perspective on the scale of evolution. Yet, more recently,
Barker et al. (2013) reviewed the nine-primaried passerines in the New
World, and proposed splitting them into as many as 16 families, some of
those families as young as just 9–10 million years old. From that
perspective, the three-way split of babblers at 11–17 mya is no longer
so dramatic. Most global checklists have adopted the three-way split,
so — once again — so do I (with some reluctance).
your preference as to what constitutes a bird Family, all the recent
research has combined to give us a much better appreciation of the
relationships of many birds. It is especially interesting to understand
what is not a babbler: Some earlier dramatic findings included:
- White-bellied "Yuhina" is actually a relict vireo living in Asia. It now goes by the name Erpornis Erpornis zantholeuca (Cibois 2003). Shrike-babblers in genus Pteruthius
are also related vireos (Reddy & Cracraft 2007) but diverged a long
time ago, and I tentatively considered them to form their own family.
traditionally considered babblers, rockfowl, rockjumpers, and
rockrunners of Africa are not babblers; the first two are now assigned
their own families near the base of the passerine tree, while
rockrunner appears to be in a new "African warbler" lineage that is
also a new family.
- Rail-babbler of tropical
southeast Asia is not a babbler, but is most closely related to
rockjumpers, and is best assigned its own family.
- All the birds named "babblers" in Madagascar, or traditionally listed as babblers in Malagasy field guides, are not babblers.
- Gray-chested "Illadopsis" Kakamega poliothorax, whose generic name commemorates the Kakamega Forest of w. Kenya, is not a babbler but is, along with Spot-throat Modulatrix stictigula and Dapple-throat Arcanator orostruthus, now tentatively placed with the sugarbirds in the Promeropidae.
And yet beyond all this, many traditional babbler genera have proved to be paraphyletic (e.g., Stachyris
is now split into 4 genera; Moyle et al. 2012). Thus the entire Babbler
"apple-cart" has been turned over, sorted out, and reassigned as the
evolutionary relationships have been sorted out. It is still a very
large group of Asian and African birds, but today's Babbler family
bears only partial resemblance to the 'traditional' babblers of yore.
Turning to what remains of the family Timaliidae, the tree babblers in genus Stachyris and Stachyridopsis are among the few "true" babblers still assigned to this family. 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, except that
Moyle et al. (2012) found that the two miniature tit-babblers in the
Philippines, assigned to genus Micromacronus, are not babblers at all. Stachyris once had 28 species; now it has but 13. The old genera Stachyridopsis, which is now changed to Cyanoderma [with "Stachyris" chrysaeum included; Moyle et al. (2012)], has six species.
these changes have left only a 50 species in ten genera among the
down-sized Timaliidae. Included is the namesake single species in genus
Timalia, the 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 genera Mixornis (4 species) and Macronous (2 species); see Moyle et al. (2012); and there are single species in monotypic genera Dumetia (Tawny-bellied Babbler D. hyperythra) and Rhopocichla (Dark-fronted Babbler R. atriceps).
One big surprise in Gelang
et al. (2009) 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," which are now called Cupwings.
remaining genera that are called wren-babblers (e.g., Rimator, Ptiolcichla, Kenopia, Napothera, Spelaeornis)
are babblers, and most are now assigned to the Pellorneidae. But as it
turns out, according to research by Moyle et al. (2012), the six wren-babblers in genus Spelaeornis actually belong to this family [Timaliidae]. These are Bar-winged Wren-Babbler Spelaeornis troglodytoides, Tawny-breasted Wren-Babbler S. longicaudatus, Naga Wren-Babbler S. chocolatinus, Chin Hills Wren-Babbler S. oatesi, Gray-bellied Wren-Babbler S. reptatus, and Pale-throated Wren-Babbler S. kinneari.
Most of the wren-babblers are ground-loving species, elusive and
difficult to observe in the forest understory. Most of these are
quite small, chubby, long-legged birds with various patterns of spots
or streaks in brown, blackish, or rufescent plumage — Asia's version of gnateaters.
This leaves 15 species of scimitar-babblers in the genera Pomatorhinus and Megapomatorhinus to 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.
In central China, Streak-breasted Scimitar-Babbler Pomatorhinus 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 Cyanoderma ruficeps was photographed in Foping Nature Reserve, Shaanxi, China, on 13 Nov 2010. The Rusty-cheeked Scimitar-Babbler Megapomatorhinus erythrogenys was at Sat Tal in the Himalayan foothills of Uttar Pradesh, India, in March 2001.
Photos © Don Roberson; all rights reserved.
is no recent "family book" covering the tree-babblers but good coverage
of the various babbler families, including the current Timaliidae, is
in Collar & Robson (2007). The account is wonderful, with
photos, although it could not be quite up-to-date with the most current
P., P.G.P. Ericson, U. Olsson, and P. Sundberg. 2006. Phylogeny and
classification of the avian superfamily Sylvioidea. Molec.
Phylog. Evol. 38: 381-397.
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.
Cibois, A. 2003. Mitochondrial DNA phylogeny
of babblers (Timaliidae). Auk 120: 35-54.
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. Molec. Phylog. Evol. 3: 581-595.
A., M. Gelang, and E. Pasquet. 2010. An overview of the babblers and
associated groups. Systematic Notes on Asian Birds 68: 1-5.
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.
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World List of Threatened Birds. Birdlife Conserv. Ser. 4. Birdlife
Intern'l, Smithsonian Inst., Washington, D.C.
Collar, N.J., and C. Robson. 2007. "Babblers (Timaliidae)," pp. 70-291 in
Handbook of the Birds of the World (del Hoyo, J., A. Elliott & D.A.
Christie, eds). Vol. 12. Lynx Edicions, Barcelona, Spain.
M., A. Cibois, E. Pasquet, U. Olsson, P. Alström, and P.G.P.
Ericson. 2009. Phylogeny of babblers (Aves, Passeriformes): major
lineages, family limits and classification. Zoologica Scripta 38:
K.A., and J. Fjeldså. 2006. A phylogenetic supertree of oscine
passerine birds. Zoologica Scripta 35: 149-186.
R.G., M.J. Andersen, C.H. Oliveros, F.D. Steinheimer, and S. Reddy.
2012. Phylogeny and biogeography of the core Babblers (Aves:
Timaliidae). Syst. Biol. 61: 631-651.
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. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT.