Yes, I saw a few of these in flocks of "normal" black-throated laughing thrushes around Yung Shue O in Sai Kung last winter. There was a suggestion that they could be of the Hainan race monachus [actually lugens morph- see below!] - possible releases although they seemed to have popped up in several locations last year.
Dylan
[ Last edited by subbuteo at 7/10/2014 15:36 ] Author: wgeoff Time: 7/10/2014 13:50
Is it Hainan ssp or lugens morph mentioned in Birds of Southeast Asia (Robson)?
Are these seen regularly around HK? Author: subbuteo Time: 7/10/2014 14:17
Sorry Geoff, not sure- I don't have my books here- I think the lugens is the right sub sp / race / morph. Couldn't remember. The Hainan trace is different looking at pictures online. Sorry. John Allcock also saw these birds in a couple of locations last year. They have been photographed at Tai Po Kau headland.
Not sure how long they have been around.
Dylan
[ Last edited by subbuteo at 7/10/2014 15:37 ] Author: subbuteo Time: 7/10/2014 14:19
Yes, lugens morph Black-throated Laughingthrush.
I didn't realise they were regular around Hong Kong.
Are morph features transferred through breeding or are they just accidental occurrences?
If breeding (which I guess they must), what's the difference between a morph and a subspecies?
[ Last edited by wgeoff at 7/10/2014 15:23 ] Author: Jonathmartinez Time: 7/10/2014 15:37
I still haven't seen any bird like this in SW Guangdong where BTL are quite common at some site, but have started to visit these sites only since recently, so more surveys will be necessary to confirm or not if this morph occurs elswhere...
All the best,
Jonathan Author: ajohn Time: 7/10/2014 16:46
A morph is a colour form within the normal population - similar to the 'Dusky' morph of Long-tailed Shrike, or the colour forms of certain skuas/jaegers. It occurs within the range of the normal colour form and can interbreed with the normal colour form. This is unlike a subspecies, which refers to two forms separated geographically. Lugens morph BtLt turn up from time to time in HK, and for some reason seem to be seen more often at this time of year (perhaps suggesting an age-related or seasonal difference rather than a morph?)
I actually had a BtLt on Lantau a few weeks ago which I thought was of the Hainan subspecies (although views not great). Similar to this bird, but browner on the body (with virtually no grey on the underparts, unlike a typical BtLt). A description is currently being prepared for assessment. Author: kmike Time: 7/10/2014 20:41
I had dark birds like these at Ng Tung Chai from time to time.
Cheers
Mike Author: cgeoff Time: 6/01/2015 09:09
As these appear to be a relatively new phenomenon in HK, we would be grateful if records/photos of such birds were submitted to the Society.
Not sure they are such a new phenomenon - I've seen them at several locations in western parts of Sai Kung over more than ten years. I explained them from the outset as the lugens morph, which Robson suggests only occurs in the nominate race, which our birds, of natural occurrence or (much more likely?) not, presumably belong to.
In fact, I wonder where the closest records are from Guangdong? My ignorance, and grateful if anyone can shed any light. Author: wgeoff Time: 17/01/2015 20:45
Yes, lugens morph are widespread in Central and East NT. So far I have found records as follows
Wonderland Villas – Matthew Kwan – 14/12/2007 – a group, one photo
Ho Chung area – Mike Turnbull (who is he?)
Kam Shan – 2002+ - Gary Chow
Kowloon Peak and Shatin Pass - George Ho
Shing Mun – Harry Miller – Feb 2014 – a photo
Yung Shue O – Dylan Thomas – 2013
Tai Po Kau Headland – Ruy Baretto
Ng Tung Chai – Mike Kilburn
Any others?
[ Last edited by wgeoff at 19/01/2015 08:29 ] Author: lrichard Time: 18/01/2015 10:45
Re the status of Black-throated Laughingthrush in Guangdong province, records in the past 30 years (mainly HKBWS, KFBG, China Bird Reports, Jonathan Martinez) show that its stronghold is the southwest of the province, where it is common in the hills at 100-1650m (peak day-count 25 in spring) and also occasionally found in the lowlands or on the coast east to Macao.
It is also common in hills near Guangzhou (day-counts of up to 10) and can be found in all seasons in Shenzhen and occasionally a little east of Shenzhen.
Elsewhere in Guangdong, it is much scarcer with one or two reported in hill forests along the West River and in the north and east-central parts at Hei Shi Ding (all seasons), Dinghu Shan, Ba Bao Shan, Dachouding and Nan Kun Shan (mainly spring).
In the past, the populations on the hills of southwest Guangdong (which are presumably of natural occurrence) were unknown and records from Guangzhou and Hong Kong were treated as ex-captive, originating in Guangxi (Nanning and Wuzhou). It's possible that the greening of Guangdong has allowed the species to spread naturally from the southwest or along the West River to reach the Pearl River Delta, but this is not certain.
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