Laughingthrush split ? (1 Viewer)

I've just noticed a couple of Laughingthrushes that I haven't heard of (Bhutan and Assam) are mentioned on a thread by Tim. I can't find anything on them. Are they splits of Chestnut-crowned perchance (guessing !)

Anyone up on the breakdown ?

Hi Larry,
Bhutan (G. imbricatus) is split from Streaked, Assam from Chestnut-crowned (crysopterus) both mentioned as sub-sps. in Birds of Indian Subcontinent Grimmett & Inskipp(s))
H

Hi Larry,
Tim is drawing mostly from the Ripley Guide. I will leave it to others to comment on how many of the splits proposed in the book are valid or not, suffice to say that peer-review is needed. In any case, op.cit.: "Assam Laughingthrush - Trochalopteron chrysopterum - (Khasi) Red-headed Laughingthrush Garrulax erythrocephalus chrysopterus; usually considered conspecific with T. erythrocephalum" THE JUSTIFICATION: Striking morphological and consistent vocal differences from other racial groups argue for specific status, as is also the case for two extralimital SE Asian racial groups; and "Bhutan Laughingthrush - Trochalopteron imbricatum - Bhutan Streaked Laughingthrush; usually considered conspecific with T. lineatum" THE JUSTIFICATION: Considered a distinct species here, as imbricatum is morphologically very distinct from G. lineatum, evidently not intergrading despite close geographical approach. Most of its vocalisations differ considerably, and tape playback yielded no response; further study needed.

Thanks folks.

See Nigel Collars paper on 44 taxonomic splits within the babblers in the latest Forktail (available to member of Oriental Bird Club), morphologically most of these splits make sense to me (both from personal observations & reading Nigels excellent paper, though I'm still unsure of one or two english names he proposes!), especially the splitting of the 'Chestnut-crowned' Laughingthrush complex. Vocalisations are certainly distinct in most of the cases written up, though not so much for Chestnut-crowned, they just all look very different!

BTW Larry, in case you have visited Malaysia, then Malayan Laughingthrush is also split from Chestnut-crowned.

James Eaton said:

See Nigel Collars paper on 44 taxonomic splits within the babblers in the latest Forktail (available to member of Oriental Bird Club), morphologically most of these splits make sense to me (both from personal observations & reading Nigels excellent paper, though I'm still unsure of one or two english names he proposes!)...Vocalisations are certainly distinct...

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The only problem being that voices should be used with great care when dealing with oscine taxonomy (greater than when dealing with suboscines and some non-passerines due to the differences in the vocal structures). I was somewhat surprised when seeing that Collar's paper dealt with 44 (!) splits in a wide range of genera (indeed, probably comprising at least two families), despite not being that much longer than the average paper which deals with taxonomical changes in birds. There are greater argumentation for splitting the Variable Antshrike (Thamnophilus caerulescens) into multiple species (it's a suboscine where voice and plumage vary greatly over its range) than many of the splits in Collar's paper. However, papers published within the last two years have shown that, at least the taxa involved in Bolivia (this includes most of the distinctively different taxa), all are part of a single species as per BSC. Anyway, having read Collar's paper a few times by now, I think there can be few doubts that most of his splits are the "real thing", but admittedly didn't find all the conclusions particularly convincing, as the taxonomy of at least some of these groups evidently is highly complex, often involves allopatric taxa and some of the plumage details clearly are highly plastic. I can't help wondering why he didn't include some biochemical work to support his conclusions, as he clearly has contacts that would have been able to do this. In my opinion it would have been better if the paper had dealt with less groups, but been more of a final word, which I suspect the current paper won't be (both in terms of lumping and splitting). Anyway, the splitting is done (and as said earlier; much of it probably rightfully so) and will probably all be followed without much additional thought in the forthcomming volume of HBW, as I can understand Nigel is involved in it.

Wow fascinating stuff . I just can't keep up, looks like I really should finally join OBC !

Rasmus Boegh said:

Anyway, the splitting is done (and as said earlier; much of it probably rightfully so) and will probably all be followed without much additional thought in the forthcomming volume of HBW, as I can understand Nigel is involved in it.

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A bit of a coincidence that the paper was published a year before publication of HBW vol 12 (Nigel Collar is the chief writer for this)!

Agree with you Rasmus, some cases the final conclusion seemed a little rushed, particularly for the minature-babblers, a little surprised at this split and the scoring system but having spoken to Nigel at some length about some this, he managed to convince me.

Where would Asian taxonomy be without NC though....

Larry, you have no reason not to join now! Especially with Rheindt's recent article on warblers in Asia and there will be another great article in the forthcoming Birding Asia....

Hi James,
You probably have seen this already. In any case, a note from John Pennhallurick in re Babbler taxonomy. I looked on this site and it would seem to be reflected in his update of the Sibley-Monroe taxonomy on his site.

"I wanted you to know that Craig Robson has kindly sent me the prelimianry
taxonomy for the Babblers section in the forthcoming volume of Handbook of
the Birds of the World. I am in the process of implementing it in my
website: http://worldbirdinfo.net <http://worldbirdinfo.net/>

John Pennhallurick"

Which form(s) of "Chestnut-crowned" Laugingthrush occur at Doi Ithanon in Thailand ? Clements notes melanostigma and schistaceafor mountains in NW Thailand. Are these forms now both under the new G melanostigmaor is Schistacea under erythrocephalusstill (or something else !)

yours confusedly

Larry

Larry Wheatland said:

Which form(s) of "Chestnut-crowned" Laugingthrush occur at Doi Ithanon in Thailand ? Clements notes melanostigma and schistaceafor mountains in NW Thailand. Are these forms now both under the new G melanostigmaor is Schistacea under erythrocephalusstill (or something else !)

yours confusedly

Larry

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It's melanostigma at Doi Inthanon (I presume you just forgot an "n"). The taxon schistaceus occurs a bit further north, and is, if following the new taxonomy, a subspecies of Silver-eared Laughingthrush (G. melanostigma).

Larry,

Hope this clarifies the situation.

G. m. connectens - NE & C Laos, SE Yunnan, NW Vietnam
G. m. subconnectens - Doi Phu Kha (N Thailand)
G. m. schistaceus - E Myanmar, N Thailand
G. m. melanostigma - E & SE Myanmar, NW Thailand
G. m. ramsayi - southern SE Myanmar

Incidently, following observations of several races of 'Assam Laughingthrush' from Meghalaya, Nagaland, Chin Hills & Mishmi Hill comparing them with birds from Arunachal Pradesh and Yunnan (Chestnut-crowned Laughingthrush) I would be wary of this is a split. Vocally the bird uttered a whole range of overlapping vocalisations and clinal variation between Western Arunachal Pradesh all the way through to Nagaland was noticeable. Would like to read more on this subject, Collar's paper does not address this issue due to lack of data, I hope data has surfaced for the split to be beyond doubt for the upcoming HBW.

Thanks guys.