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Subject: Status of Red-billed Leiothrix [Print This Page]

Author: ajohn Time: 13/01/2013 19:19 Subject: Status of Red-billed Leiothrix

Over the last week or so I have seen a few flocks of Red-billed Leitohrix in the New Territories - four different flocks (at least 13 birds) around Pat Sin Leng and a flock at Tai Po Kau. This seems to be fairly unusual - normally I find this species fairly uncommon in HK, and the established breeding population seems (at least to me) to be largely confined to Tai Mo Shan and the upper areas of Shing Mun.

This has led me to three questions:
1. Has anybody else noticed increased numbers of this species in HK this winter?

2. Where have these birds come from? The flocks at Pat Sin Leng are a fair distance from the breeding population at Tai Mo Shan. Is anyone aware of them breeding near Pat Sin Leng?

3. Does the RC ever assess the status of species such as this to consider whether truly wild birds may occur in HK?

I know it is a very common cage bird, and there is a high chance of escapes occurring, but these sightings have been in several locations over a short period, some fairly remote from human populations. I have previously seen the species in the north-east, but only once or twice and I think only in mid-winter (January-February), despite the fact that I often visit the area in spring, summer and autumn.
I know it is considered to be a truly resident species and is probably considered incapable of making it here unaided, but this was also the accepted wisdom about Pygmy Wren-babbler until they suddenly started turning up in HK. It is a common bird in some south China forests, but I don't know how close the nearest wild populations are to HK.

Author: wilsondring Time: 13/01/2013 19:30

I have seen three or four at Shing Mun last week and a flock at Tai Po Kau today ..

Author: brendank Time: 13/01/2013 21:36

I didn't see it but I was surprised when a photographer showed me a photo of one at Lung Fu Shan about a week ago. I have never seen one HK island before.

I think in past few years they have been fairly common at Tai Po Kau.

Author: samchang Time: 13/01/2013 21:50

I took photo of it once in Lung Fu Shan last Aug, but no more afterwards.

Author: kpokuen Time: 13/01/2013 22:35

There was a small population in the upper part of the valley, more than 7 years ago.

However Peking robin become scare in recent years, mostly seen in the upper part of the valley or end of the red walk.

Occasionally single or two and three were recorded in the lower valley, such as picnic#1, that I would consider as escapes.

This winter is an explosion in numbers and more than one flocks are seen, spreading across the whole tpk catchment area.

I also think this sudden increase in number interesting.

Kwan

[ Last edited by kpokuen at 13/01/2013 22:36 ]

Author: bkenneth Time: 13/01/2013 23:13

I saw a flock at the forest trail road at the top of Tai Po Kau last weekend.

Ken

Author: Jonathmartinez Time: 14/01/2013 09:11

to make a chinese correlation, in November I've been in central Guangxi, at a place where I'm going very reguraly, I've recorded Red-billed Leiotrix for my first time there (after 6 trips at different time of the year ), at a few sites I've visited very often in the past. A flock of them was seen in a habitat that do not correspond to the species as well indicating some birds in movment I guess.The nearest population I know is about 200 kms from there, so I wont be surprised that this species is subject to local movment elsewhere in winter.

All the best,

Jonathan

Author: wcaptain Time: 14/01/2013 11:07

Bird release?

Author: Jonathmartinez Time: 14/01/2013 11:29

not where I'm going, very remote area in country side quite far from any city...with a few sightings in a very short time where i haven't got any before...I also notice some movment of a few others species, like Grey-cheeked Fulveta I had some birds where I've never seen any before, and Black-breasted Scimitar Babbler, also my first sighting in this area.

All the best,

Jonathan

Author: ajohn Time: 14/01/2013 18:11

It is very easy to say all birds are the result of releases for species such as this, and to leave that as the status for evermore. There is no question that Red-billed Leiothrix is common in the cage bird trade, and no doubt some escapes or deliberate releases occur (Hong Kong Island in August would seem to me to be a very likely release).

The point I was trying to make is that it may be worth keeping an open mind rather than just flippantly saying 'Bird Release' for all records. The RC regularly reassesses Cat III birds to assess whether wild birds may be occurring (Small Niltava, Mrs Gould's Sunbird and Hawfinch being recent examples of species which have changed status). I was trying to ask whether similar assessments are done for Cat II species. Most of these would be very difficult because they are currently so widespread (Rufous-capped Babbler, Greater Necklaced Laughingthrush etc.), but Red-billed Leiothrix is generally, in my opinion, a rather uncommon bird in HK with a fairly restricted distribution.

I am not saying these birds are wild or that the current status is necessarily incorrect. It may be that there are feral populations I am not aware of or that the population on TMS has had a very successful breeding season and spread to other sites. But if there has been a sudden, simultaneous increase in numbers at geographically-separated sites away from human activity, it seems unlikely to me that these are all the result of recent releases and that something else may be going on.

Any reassessment would, of course, require the consideration of appropriate information, for example the current status of feral populations, the current status in the cage bird trade, the current status over the border in China, any evidence for movements of the species and any pattern in records.

Author: lrichard Time: 14/01/2013 21:21

The HK Avifauna sets out quite strong evidence (especially 15 out of 43 birds trapped in 1996-1997 showing signs of captive origins) for not treating HK populations as wild.

It is locally common in Guangdong. The first known records were at Luofu Shan, which is only 80-90 km due north of HK, in the early 1900s and Siu Hang, Shaoguan in the 1920s (type locality of the subspecies kwangtungensis). Recent records are from Ba Bao Shan (Nanling), Che Ba Ling, Dachaoding, Luokeng and Sanyue, all in the north, and Dawuling, Dinghu Shan, Nankun Shan, Gutian, Lianhua Shan, Luofu Shan and Wutong Shan, all in the south.

Wutong Shan is the big mountain on the HK-Shenzhen border, and birds recorded there could of course have originated in HK. The question for me is whether birds from Luofu Shan or a nearby site such as Gutian or Lianhua Shan could reach HK naturally.

Author: wgeoff Time: 15/01/2013 06:32

The current Cat II description refers to the status of the breeding population in HK. Red-billed Leiothrix is in Cat IIA which is defined as

Category IIA: southeast China breeding species, the currently established HK breeding population of which is considered to derive from captive stock, but which probably occurred in HK prior to habitat changes.

whereas Cat I does not refer to breeding and simply says

Category I: species that have been recorded in an apparently wild state in HK.

There is an issue here, that birds could be in both categories - summer breeders from an ex-captive stock and winter visitors from a wild stock.

If there has been an increase in numbers this winter from wild sources, as may be the case, then I guess these birds would have to stay to breed before the species could be re-classified to another category. Or there would have to be regular annual winter visitors from wild sources - difficult to prove.

Another headache for the Records Committee.

[ Last edited by wgeoff at 15/01/2013 07:18 ]

Author: subbuteo Time: 15/01/2013 08:14

Could maturation of forest habitat be leading to dispersal? Or is a reduction of suitable habitat north of HK leading to more movement south plausible? I am surprised that red-billed leothrix is not recorded more on HK island as an established breeding bird. I know silver-eared mesia was on Braemar Hill in the 1990s- obviously another release bird. I can't recall ever seeing leothrix there though. Anecdotally, I would say leothrix is more common in the bird trade.

I have always found red-billed leothrix very hard to actually see, I often suspect they are scrabbling away in the undergrowth out of sight and normally get no more than a glimpse of them through foliage so they are probably under-reported (at least by me!).

Dylan

Author: kena2089 Time: 15/01/2013 12:18 Subject: Red-billed Leiothrix

On 30.12 2012, I have seen one of Red-bill Leiothrix and a flock of Silver eared Mesia taking bath at Lung Fu Shan (龍虎山). I took the Photos. On 03.1.2013, I also seen them at the same place.

Image Attachment: [30.12.2012 Lung Fu Shan] R001.jpg (15/01/2013 12:18, 33.29 KB) / Download count 564
http://hkbws.org.hk/BBS/attachment.php?aid=13714

Image Attachment: [30.12.2012 Lung Fu Shan] R002.jpg (15/01/2013 12:18, 47.78 KB) / Download count 541
http://hkbws.org.hk/BBS/attachment.php?aid=13715

Image Attachment: [03.01.2013 Lung Fu Shan] R003.jpg (15/01/2013 12:18, 30.48 KB) / Download count 549
http://hkbws.org.hk/BBS/attachment.php?aid=13716

Author: JamesLambo Time: 28/02/2013 08:49 Subject: a few more records

I have come across a few flocks in Tai Po Kau recently: two flocks, 5 birds and c.10 birds, 9-Feb-2013; one pair 15-Feb-2013.

However, I also have other winter records for TPK: c.5 in a birdwave 2-Feb-12; and a flock of c.12 on 16 Dec 2011.

(Any other records I have are from Upper Shing Mun (winter) and Tai Mo Shan (June) - but I rarely visit these areas)

James Lambert

Author: ajohn Time: 28/02/2013 23:08

As Richard mentions, the Avifauna does provide evidence for the presence of escaped/released birds in Hong Kong, including the high proportion of individuals showing cage damage.

On the other hand, the Avifauna also highlights the fact that a high proportion of cage-damaged birds may indicate that the population (at least at that time) was not self-sustaining. Furthermore, it points out that after the species was listed by CITES in 1997 there was a decline in the number of records in Hong Kong (again, supporting the presence of released birds). This decline appears to have continued according to records in the bird report e.g. peaks counts of three in 2008 and 2009, and only two records in 2010.

This is the basis for me suggesting that this winter may be unusual - there are relatively few records in recent years of this species, whether related to cage releases or otherwise, and yet suddenly it seems to have appeared a several different sites over a short period of time. This influx has coincided with high numbers of other species e.g. record numbers of Chestnut-collared Yuhina and Tristram's Bunting.

I find it hard to exaplin the influx in terms of captive release - the CITES ban which supposedly led to a reduction in escapes previously remains in place, and it is hard to see why there should suddenly be an increase in releases at a number of different locations. I initially wonder whether an assessment of status in light of the CITES ban (introduced over 15 years ago) might be justified.

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