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Subject: Black-headed Bunting [Print This Page]

Author: wleepoin Time: 21/10/2010 21:33 Subject: Black-headed Bunting

1st winter male

1st Winter

PWMK

[ Last edited by wleepoin at 24/10/2010 21:51 ]

Author: lpaul Time: 21/10/2010 23:47

I have long been a bit mystified by the fact that most Black-headed Buntings in HK are apparently adult females. Adults can easily be aged in autumn as they show very obvious wear to all the plumage, but especially the primaries and tail. As such both these, which are in very fresh plumage, are first-winter birds. The first bird therefore (with the ghosting of the male head pattern and bright yellow below) is presumably a male. Like a number of other records, the first bird shows what looks like tail damage; however as this species breeds no closer than the Caucasus Mts/N Iran (like Red-breasted Flycatcher) - it being replaced by Red-headed Bunting east of there - it seems unlikley that these are escaped cage birds. HK must account for the vast majority of Chinese records.

Author: HFCheung Time: 22/10/2010 11:05

Dear Paul,

Do you mean to say "it seems likley that these are escaped cage birds"?

HF Cheung

Author: tmichael Time: 22/10/2010 14:04

Paul can and no doubt will answer for himself, and though I can see where the query by HF comes from, I think Paul means what he has typed ie there are (presumablyand extremely plausibly, though not proven to be) no supply lines of cage birds from the Caucasus/N. Iran to S. China.

However, what I really wonder about is whether anybody knows whether Bh Bunting is ever seen as cagebird in anywhere in China?

One would expect not unless one of the vagrants/regular small wintering population (take you pick!) is trapped to the west of here, say in Yunnan.

Also it's interesting that minor regular 'wear and tear' tail damage is being suggested as occurring regularly in this species, highlighting the difficulties in dismissing too firmly the possibly wild origins of birds of other species on similar grounds.

Mike Turnbull

Author: ddavid Time: 22/10/2010 20:49

Hawfinch!!??

Author: lpaul Time: 22/10/2010 22:02

To confirm, I think these birds are unlikely to be escapes.

Assessing escape likelihood is often rather difficult, and as has been implied here, if these BH Buntings are consistently showing plumage damage, then that may have implications for the assessment of other species.

However, assessing escape likelihood should be based on a combination of criteria, and this includes pattern of records and status in the trade. Pattern of records is most difficult to interpret when you are dealing with extreme rarities, when by definition; there is no pattern of records.  In such circumstances, regional distribution, moult pattern, and status in the cage bird trade are also important, as are age, and sometimes, sex.

In the case of BH Bunting, given the range and what we know of the cage bird trade, it seems most unlikely that there are any in the trade in China.  Even if there was a small wintering population in Yunnan (for example) the chances of these birds being trapped and released or escaping in HK in small numbers (up to ten per year) every October and November must be very slim indeed.

Also, if you look at a map, birds migrating from the breeding grounds to the wintering grounds (which are largely within the Indian subcontinent) which were to overshoot would end up in S China.

However, if these birds are indeed wild, then the wear and tear they show is rather exceptional.  Certainly none of the eastern Palaearctic buntings we routinely see in HK show such wear.  This is in large part due to the fact that adults do not have a post breeding moult before migrating (whereas most migrant passerines do) and I would guess, in part due to the more arid environment in which BH Buntings breed which is likely to result in more bleaching and abrasion of feathers. Why first-winter birds might show such damage (albeit to a much lesser extent) is more difficult to explain, but environment may play an important part.

Hawfinch, on the other grounds is entirely different.  Adults undergo a complete post breeding moult, it is common in the cage bird trade, and the pattern of records is less clear; accordingly any suggestion of cage damage is potentially far more significant.

Author: yyattung Time: 23/10/2010 10:14

The Black-headed Bunting is also recently recorded at Zhejiang too.

http://bbs.zmnh.com/viewthread.php?tid=14617&extra=page%3D1

Author: ajohn Time: 23/10/2010 18:58

Quote:

Original posted by lpaul at 22/10/2010 22:02
Pattern of records is most difficult to interpret when you are dealing with extreme rarities, when by definition; there is no pattern of records. In such circumstances, regional distribution, moult pattern, and status in the cage bird trade are also important, as are age, and sometimes, sex

What is the thinking behond Greater Short-toed Lark? No pattern of occurrence (1 record), no evidence of the species occurring elsewhere in southern China, and larks are common in the cage bird trade (OK, most aren't Short-toed, but then how common is Purple Cochoa, and that has been seen in HK.) And yet the species was accepted to Category A (what's it called now? Category I?)

I ask in part because I saw a Mongolian Lark today - this has a similar range and has previously been recorded at a similar time of year, but previous birds have always been dismissed as escapes. Absolutely no evidence of cage damage on today's bird, incidentally, and recent conditions are surely good for migrants from the north-east... http://www.hko.gov.hk/wxinfo/trajectory/trajectory_e.shtml

Author: tmichael Time: 23/10/2010 19:11

On the subject of Greater Short-toed Lark, wasn't there one a few years ago (around this time?) at Pui O, which fatally lowered a wing slightly in one photograph?

Can't find it through the search and maybe I'm mistaken.

PS I saw Mongolian Lark at LV in 2000 during the coldest last weekend of Feb I can remember - the first winter bird race, I think.

Mike Turnbull

Author: Beetle Time: 23/10/2010 21:33

just for reference, i also saw a mongolian lark kept in cage by an old man with very good feather conditions today....
So i believe there are trading of cage birds for this species.

Author: cgeoff Time: 24/10/2010 09:11

Mongolian Larks are very common in the cage-bird trade, or at least were the last time I was able to look. It would be useful if any Society members who are interested could monitor the bird markets and keep a record of the species present. You could submit the records to the Society in the normal way using the Excel spreadsheet that can be downloaded elsewhere on the website. If the records are fairly systematic and cover a reasonably long period of time, it would probably be sufficient to form the basis of a short paper in the HKBR.

Greater Short-toed Lark is an issue, and appears to be somewhat anomalous. The RC is aware of this and has recently acquired the original photos taken by one of the observers. However, assessing this record may take some time given the number of subspecies occurring.

The bird at Pui O was never formally submitted as far as I'm aware.

GeoffC

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