brendank

12 March 2011--Tai Shan River

I think it is wild... Seems rather shy like a wild bird.  Thanks Allan!

mandarin_duck.JPG (118.25 KB)

13/03/2011 22:40

sdavid

Whereabouts is Tai Shan River? Not a site I'm familiar with.

ajohn

David Stanton and I saw this bird on Monday evening, in the same location on Tan Shan River (for those who are not familiar with the site, Tan Shan River is on the southern side of Sha Tau Kok road).
Fortunately the bird was standing out of the water when we managed to find it. We were able to get scope views of both legs, and confirmed that the bird is not ringed.
I have some personal doubts about the record, however. Contrary to Brendan's suggestion that the bird is shy, I was concerned that it was directly across the river from a village house - perhaps only 10-15m from the house. There are a number of other habitat options in the area (including e.g. the reservoirs at Ho Pui/Lau Shui Heung), and I would expect a wild bird to be a bit more shy and avoid a location with such levels of disturbance.
I am also concerned that I know there is (or, at least, used to be) an aviculturalist in this area - I have previously been hiking in the area and heard exotic bird calls coming from the back of one of the houses (including e.g. Grey Peacock-Pheasant).

Mandarin is a tricky species in a Hong Kong context. HK is close to the natural range, and in the past the species has apparently occurred here in a natural state. There is no reason that wild birds should not continue to occur here. However, this is a very frequently traded species and it is very difficult with each individual to be sure of possible provenance.

As an example, the Mandarin pair I found at Kam Tin a few years ago included a male with a plastic ring (cable-tie?) on one leg, suggesting a captive origin - this was not visible when I first found the birds, and only later discovered from photos. The female of that pair had no such evidence of captive origin. These birds apparently disappeared for the entire summer, reappearing the following winter - at one point with an additional female. It is feasible that one or both females were from a wild population but it seems more likely that these were from the same (unknown) origin as the male. Without photos showing the ring on the male, these would perhaps have been considered wild, as has been suggested for the current birds.

Overall, I have now seen 5 free-flying Mandarins in Hong Kong. The species is not currently on my HK list - I was hoping the Tan Shan bird would change this, but somehow it just didn't feel right for a wild bird and I have still not added it to my list.

brendank

My comment that the bird was shy was based on this. When I arrived at 5:00 pm at the site no bird was present.  After walking around the area for a while, I returned to the spot at 6:00 pm at which point the bird was present.  When I started photographing it, it swam away and hid in the grass mostly out of few.

If there is an aviculturist nearby that is worrying. However, as with the Hawfinch and Red-headed Buntings I find it strange when different individual birds show up at different sites.  Why should two Mandarin Ducks escape at the same period in time? Geoff Carey's explanation with regards to the Hawfinch makes since but I would think Mandarin Ducks would be prized possessions and not likely disposed of in the way a Hawfinch would be.

ajohn

The fact that two birds are found at a similar time does not necessarily mean that they escaped at the same time. Alternatively, the fact that they are found at two different locations does not necessarily mean that they escaped from two locations. Once they are free-flying, birds such as this could be very mobile. As I mentioned in my earlier post, the KT mandarins disappeared for a long period over the summer and then reappeared the following winter - presumably they went somewhere in the intervening period. Similarly the fantail at Ng Tung Chai has appeared over a number of separate winters but disappeared during the summer.

It is possible that the presence of these two individuals is linked i.e. the birds arrived in HK, or escaped, together and have subsequently ended up in different locations. The simultaneous appearance of mandarins (or indeed Hawfinches or Red-headed Buntings) at more than one site does not prove a wild origin for any of these individuals.

Mandarins are common (and I think relatively easy to breed) in captivity - I'm not sure how highly valued they are. They have apparently been declining gradually in their native range, yet there seems to have been an increase in the number of records in HK in recent years and my impression is that the species currently seems to be almost annual here (although I don't have the data to back this up!). Some are obvious escapes, some are not. It is even possible that many of the recent records relate to the same individuals which could be mobile throughout HK or further afield.

There is always a problem with separating possible wild individuals from ex-captive individuals. As I said, something about this individual didn't feel right to me. Perhaps it is wild - I don't know - but I didn't think that at the time (in fact, I thought the KT birds seemed more like wild birds than this individual).

Incidentally, the only photos I have seen of the Lam Tsuen bird (male) are those posted a couple of days ago by Vivian. I understand there are more photos of this individual - are these still available online? Also, has anyone seen the legs on this bird to assess whether or not it is ringed. At the time of the KT birds, it was suggested that males are more often ringed in captivity than females because males are more highly valued in the trade.

lalan

17 March 2011--Tai Shan River
add more picture,
and one question wild mandarin duck would like woodland river of pond? i found a male mandarin duck is at fish pond in tai shun wai

ajohn

Mandarin is usually a species associated with wooded rivers and lakes. The fact that there are a number of records from fish ponds in the Deep Bay area (e.g. Tai Sang Wai, Mong Tseng) is one thing that concerns me about the recent occurrence of the species in HK. I would think some of the smaller reservoirs (e.g. Hok Tau, Ho Pui) should provide better habitat.

lmichael

The discussion over the origin of this bird prompted me to see for myself. I found her on the bank about 30m upstream from the village house. She was somewhat obscured by vegetation so after watching from the bridge for a while I then went into the bamboo clump beyond the bridge which allowed me to get closer. This was quite a noisy affair and she became alert but did not try to hide or show any indication of flying. In my view based on experience in mainland China such tameness is atypical. I also find it somewhat strange that she has remained on such a short stretch of river for so long.

I'm not saying that I am sure that this is an ex-captive bird, but if I had to choose one way or the other I am afraid that I think that this is more likely than not.

Cheers

Mike Leven

brendank

I am surprised that there aren't more birds seen on Hong Kong reservoirs (e.g. Hok Tau, Ho Pui, Shing Mun) in general. I would think they would at least be able to have some wintering Tufted Ducks, Common Teals, Little Grebes, etc.  It seems at best they get a migrant Little Grebe once and a while.

EricB

Statistically, extralimital wildfowl will always have the potential to have ‘escaped from captivity’. Markers of captivity – rings and flight feather damage only point to the most obvious of escapees.

Logic would suggest that extralimital species like the Mandarin, which migrates southwards in the winter , may over shoot in the Autumn and end up in HK.
As always, first winter birds are less good at navigating and a first winter Autumn Mandarin is going to be your best candidate for vagrancy – I am unaware of any identification criteria that point towards a 1st winter bird and I think they basically look like a female.

Spring birds will be birds moving back North but would have had to have wintered further South, which statistically is less likely. Naturally, captive birds which have been transported further South and then escaped, will be among the most likely group of Mandarins to turn up in Spring.

As always, there are things that some birds do that seem totally unpredictable; this is probably more to do with our understanding of the weather systems and circumstances that go with the individual bird rather than them being totally random events.

There is hope with isotopes studies on birds feathers to determine the origin of where the bird was feeding when it produced its latest batch of feathers.
Much of this is 'work in progress' , but it won’t be too long before ( and may actually be possible already) stable-hydrogen isotope analysis in feathers can be used to work out  whether this Mandarin spent its winter feeding in Thailand or China! All you need is a feather for analysis and a large wallet.

Many of you will be aware of the usage of these scientific techniques in European Baikal Teal records to show a Siberian origin of individual bird/s.
http://www.surfbirds.com/forum/showthread.php?t=6201

Here are some articles you may find of interest.

http://blx1.bto.org/pdf/ringmigration/24_3/coiffait.pdf

http://www.americanbirding.org/p ... l36no2p142to145.pdf

If you have problems downloading them, drop me an e mail and I can send you the pdf.

eric

ddavid

Vivian mentioned in her posting that the Mandarin in Lam Tsuen was shot. Let's hope that some of the feathers were saved so that they can be sent off to be isotopically analysed so that this complex problem can be brought to some kind of fruition.... although, of course, anyone who has possession of the feathers might not be able to afford the cost of such a detailed analysis ...

david

EricB

If you've got a feather or two, try  e mailing this guy :  j.newton@suerc.gla.ac.uk - he may be able to help  or point you to the right people.
eRic

lpaul

When Vivian said shot, I think she menat with a camera...