Laughingthrush
The Laughingthrushes are the genus Garrulax of the large Old World babbler family of passerine birds. They occur in tropical Asia, with the greatest number of species occurring in the Himalaya and southern China.
These are rangy, medium-sized, floppy-tailed landbirds with soft fluffy plumage. These birds have strong legs and are quite terrestrial. This group is not strongly migratory, and most species have short rounded wings, and a weak flight.
A few, like the Streaked Laughingthrush occur in fairly open habitats, but most are jungle species, difficult to observe in the dense vegetation they prefer.
Like other babblers, these are noisy birds, and the characteristic laughing calls are often the best indication that these birds are present. As with other babbler species, they frequently occur in groups of up to a dozen, and the rainforest species like the Ashy-headed Laughingthrush often occur in the mixed feeding flocks typical of tropical Asian jungle.
Systematics
As with some other babblers, this genus has turned out to be highly polyphyletic. Rather than forming a natural evolutionary group of closest relatives, the laughingthrushes are spread about the entire babbler family. This is quite apparent by their diverse morphology and presence of several groups with distinct color patterns, but the rarity of several species and the sheer number of taxa have hitherto prevented a thorough revision. Before this paraphyly was realized to be as dramatic as it is, it was generally assumed that the laughingthrushes were a clade comprising several subgenera.
This has much confounded further research: most molecular phylogeny studies, for example, used only the White-crested Laughingthrush as an "example" of this "genus", because specimens were readily available. Morphological studies, on the other hand, had usually more material at their disposal, but these too were generally conducted under a false assumption of monophyly. A 2003 study,[1] analyzing mtDNA cytochrome b and 12S/16S rRNA data of a number of laughingthrushes, did establish however that there is no such thing as a "representative" laughingthrush. Consequently most of the work regarding the evolution of this assemblage needs to be evaluated anew and if necessary even redone. Indeed, the taxon Garrulax would need to be restricted to the type species (Rufous-fronted Laughingthrush) and its closest relatives, but the species generally considered the most likely candidates have not been comprehensively studied in recent times.[2]
Species list
The list below uses the treatment of the laughingthrushes by Birds of South Asia[3] and the Handbook of Birds of the World[4] as a baseline, acknowledging the polyphyly of Garrulax and attempting to reorganise it into monophyletic genera.
This list is by no means the last word on the subject though, and it is very likely that some of the new groups will be revised, expanded or split as more species are studied in the future; additional laughingthrushes are presently elevated to species status and even hitherto unknown taxa are discovered at a rate of about 1-2 per year. Some proposed small or monotypic genera on the other hand might ultimately be merged with others for convenience if they turn out to be sister taxa. All in all, the resolution of the laughingthrush assemblage's taxonomy depends on a resolution of the Old World babblers' systematics in general.
- Genus Garrulax sensu stricto - Close to Chinese Babax (Babax lanceolatus)?
- White-crested Laughingthrush, Garrulax leucolophus
- Sumatran Laughingthrush, Garrulax bicolor
- Lesser Necklaced Laughingthrush, Garrulax monileger
- Greater Necklaced Laughingthrush, Garrulax pectoralis
- White-throated Laughingthrush, Garrulax albogularis
- Rufous-crowned Laughingthrush, Garrulax ruficeps - formerly in G. albogularis
- Masked Laughingthrush, Garrulax perspicillatus
- Rufous-fronted Laughingthrush, Garrulax rufifrons
- Ashy-headed Laughingthrush, Garrulax cinereifrons
- Sunda Laughingthrush or Grey-and-brown Laughingbird, Garrulax palliatus
- incertae sedis - Garrulax or Dryonastes?
- Grey Laughingthrush, Garrulax/Dryonastes maesi
- Rufous-cheeked Laughingthrush, Garrulax/Dryonastes castanotis - formerly in G./D. maesi
- Black-hooded Laughingthrush, Garrulax/Dryonastes milleti
- Kon Tum Black-hooded Laughingthrush, Garrulax/Dryonastes milleti sweeti
- Cambodian Laughingthrush, Garrulax/Dryonastes ferrarius - formerly in G./D. strepitans
- White-necked Laughingthrush, Garrulax/Dryonastes strepitans
- Proposed genus Dryonastes
- Grey-sided Laughingthrush, Dryonastes caerulatus
- Rusty Laughingthrush, Dryonastes poecilorhynchus
- Buffy Laughingthrush, Dryonastes berthemyi - formerly in D. poecilorhynchus
- Black-throated Laughingthrush, Dryonastes chinensis
- Chestnut-backed Laughingthrush, Dryonastes nuchalis
- Rufous-vented Laughingthrush, Dryonastes gularis
- Wynaad Laughingthrush, Dryonastes delesserti
- Blue-crowned Laughingthrush or Courtois's Laughingbird, Dryonastes courtoisi - formerly in D. galbanus
- Yellow-throated Laughingthrush, Dryonastes galbanus
- White-cheeked Laughingthrush, Dryonastes vassali
- Rufous-necked Laughingthrush, Dryonastes ruficollis
- Proposed genus Melanocichla
- Proposed genus Rhinocichla - Chestnut-capped Laughingthrushes
- Spectacled Laughingthrush, Rhinocichla mitrata
- Chestnut-hooded Laughingthrush, Rhinocichla treacheri - formerly in R. mitrata
- Proposed genus Stactocichla
- Proposed genus Leucodioptron
- Proposed genus Pterorhinus
- incertae sedis - Ianthocincla or Trochalopteron?
- Proposed genus Trochalopteron
- Scaly Laughingthrush, Trochalopteron subunicolor
- Blue-winged Laughingthrush, Trochalopteron squamatum
- Brown-cheeked Laughingthrush or Prince Henry's Laughingthrush, Trochalopteron henrici
- Elliot's Laughingthrush, Trochalopteron elliotii
- Variegated Laughingthrush, Trochalopteron variegatum
- White-whiskered Laughingthrush, Trochalopteron morrisonianum
- Black-faced Laughingthrush, Trochalopteron affine
- Chestnut-crowned Laughingthrush, Trochalopteron erythrocephalum
- Assam Laughingthrush, Trochalopteron chrysopterum - formerly in T. erythrocephalum
- Silver-eared Laughingthrush, Trochalopteron melanostigma - formerly in T. erythrocephalum
- Malayan Laughingthrush, Trochalopteron peninsulae - formerly in T. erythrocephalum
- Golden-winged Laughingthrush, Trochalopteron ngoclinhense
- Collared Laughingthrush, Trochalopteron yersini
- Red-winged Laughingthrush, Trochalopteron formosum
- Red-tailed Laughingthrush, Trochalopteron milnei
References
- ^ Cibois (2003)
- ^ Cibois (2003), Pasquet et al. (2006)
- ^ Rasmussen & Anderton (2005)
- ^ Collar & Robson (2007)
- ^ But see Pasquet et al. (2006)
- Cibois, Alice (2003a): Mitochondrial DNA Phylogeny of Babblers (Timaliidae). Auk 120(1): 1-20. DOI: 10.1642/0004-8038(2003)120[0035:MDPOBT]2.0.CO;2 HTML fulltext without images
- Collar, N.J. & Robson, Craig (2007): Family Timaliidae (Babblers). In: del Hoyo, Josep; Elliott, Andrew & Christie, D.A. (eds.): Handbook of Birds of the World, Volume 12 (Picathartes to Tits and Chickadees): 70-291. Lynx Edicions, Barcelona.
- Pasquet, Eric; Bourdon, Estelle; Kalyakin, Mikhail V. & Cibois, Alice (2006). The fulvettas (Alcippe), Timaliidae, Aves): a polyphyletic group. Zoologica Scripta 35, 559–566. doi:10.1111/j.1463-6409.2006.00253.x (HTML abstract)
- Rasmussen, Pamela C. & Anderton, J.C. (2005): Birds of South Asia. The Ripley Guide. Smithsonian Institution and Lynx Edicions, Washington DC and Barcelona.
External links