wkcheng

Please assist to id this bird.

Pui O
2009.11.22

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22/11/2009 18:37

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22/11/2009 18:37

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22/11/2009 18:37

Is it Asian House Martin/Northern House Martin?

Sorry for poor quailty of the photos as it moved very fast.

tmichael

Looks like Northern to me, especially from first shot.

While there has clearly been a significant influx into South China with the exceptional weather in the last seven days or so, I think that with greater observer awareness, and a lot more people looking and taking photographs, it may turn out that this species is of rare, but regular occurrence in HK - I think the very first House Martin I saw in HK, at Tai Long Au on c 28 October 1987 was in fact Northern, as it too had a huge gleaming white rump, but it just shot through.

In fact, Brazil in Birds of East Asia says Northern occurs regularly in South China in winter, or something similar; does anyone know the reference he bases that statement on? Hopefully not on a misreading of Cheng who lumps Northern and Asian, though the Jabouille record of lagopoda for Guangzhou Bay may refer to Northern.

Mike Turnbull

wkcheng

I find 2 more photos that should be better for the identification.

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23/11/2009 20:55

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23/11/2009 20:55

Any additional comments?

lpaul

I think this is Asian House Martin.  Although the rump looks quite large, the tail is rather square (I suspect that the apparent fork is due to moult), the tail is rather short, the dusky underparts with contrasting white throat are typical of Asian, whereas in Northen the underparts are uniform white, the underwing coverts are clearly black which is diagnostic of Asian, in Northern they are grey or brownish and contrast little with the rest of the underwing.

Vaurie (1956) also has lagopodum (which the Lok Ma Chau bird at least fitted) as wintering in southern China.  In this context it is of note that the LMC bird was in active moult, so had presumably made a local movement due to the cold weather rather than being on migration.

tmichael

Certainly agree this is very clearly Asian if the second set of pictures are the same as the first bird - in the first set of pictures, though we get an impression of a squarish tail, I can't see anything else that really points to Asian, and surely the white rump looks very extensive. Could all be just the light and angles and I defer to Paul's wider knowledge.

Mike Turnbull

wkcheng

Thanks both of you in helping to id the bird.

ajohn

Mike, one thing that was noted when watching the Northern House MArtin last week was that nearby Asians could at times seem to also have a fairly large rump patch. John Holmes's recent post (http://www.hkbws.org.hk/BBS/view ... &extra=page%3D1) shows well an individual with a surprisingly large rump patch (extending to the longest uppertail coverts) which is still clearly Asian. Admittedly, this bird shows dark centres to the longest feathers but these may not be visible on photos such as the first on this thread.

In addition to the square-cut tail, another feature of Asian (just) visible on the first photos is that the black of the face seems to extend down onto the chin - on the recent Northern, this cut through the eye direct to the bill.

I think to get an acceptable record of Northern you need not only the extensive white rump but also the larger size, deeper tail fork, whiter underparts, paler underwing and head pattern. But they probably are being overlooked - I learned a lesson on the recent bird because I had expected a whiter underwing, so I dismissed the bird as Asian. Had I found the bird, the record would have been missed. Fortunately Paul Leader was more persistent with following up on the ID!