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Subject: Himalayan Swiflet [ 短咀金絲燕 ] [Print This Page]

Author: hkinni Time: 17/10/2015 01:17 Subject: Himalayan Swiflet [ 短咀金絲燕 ]

11/10/2015

Po Toi

Author: wgeoff Time: 17/10/2015 08:28

Fantastic photos Kinni! Great detail.

They show one thing about Himalayan Swiftlet photos that I've noticed from my own rather less good photos.

Compare the first photo, where the background is darker, with the last photo where the background is light. The bird appears to be much darker on the rump and undertail in the first photo than in the others.

This is important because it has been suggested that rump colour can be used to separate Himalayan from Germain's Swiftlet, which could occur in Hong Kong and has a paler rump. But from my experience and as shown here, rump colour on swiflets can vary a lot according to light conditions so I don't think it can be used to separate Swiftlet species.

For me, only the birds themselves know what species they are, and they're not telling.

[ Last edited by wgeoff at 17/10/2015 13:02 ]

Author: hmartin Time: 17/10/2015 16:01

Well at least Geoff and I agree on one thing. Great pictures, probably the best of a swiftlet taken in Hong Kong.

The observation that apparent rump colour on swiftlets depends on the light and the background at the time of observation has been made before. But if comparing like for like, especially over a series of photographs such as these, I think rump colour remains potentially useful. That said, photographs of undoubted Germain's on OBI show a much greyer rump than are displayed in museum specimens that I examined. What would be useful to know is the exact rump colour of the Germain's in Hainan, presumably the most likely source of vagrant Germain's in Hong Kong.

Whilst trawling through the OBI photographs of Germain's I came across a picture of a supposed Germain's from the Juishan Islands, Zhejiang, and following up on the reference came to this http://birdingpage.blogspot.tw/2015/07/swiftlets-to-order.html . Interesting reading and note the author's reference to a white rump, although this isn't shown in the photograph. Food for thought, as is the possibility of swiftlets straying to Hong Kong from the Philippines. It has been 20 years since the swiftlet paper was written, and with that extra 20 years of knowledge and photographs, maybe it's time to look at the swiftlet situation again?

I'm attaching a couple of shots of a Himalayan Swiftlet taken in Long Valley on 12 April this year to allow comparison with the Po Toi individual. Does anyone else have decent shots of swiftlets from Hong Kong? If so please post in this thread.

[ Last edited by hmartin at 17/10/2015 17:31 ]

Image Attachment: _62U1878himalayan-swiftlet.jpg (17/10/2015 17:31, 85.16 KB) / Download count 550
http://hkbws.org.hk/BBS/attachment.php?aid=23305

Image Attachment: _62U1880himalayan-swiftlet.jpg (17/10/2015 17:31, 78.31 KB) / Download count 552
http://hkbws.org.hk/BBS/attachment.php?aid=23306

Author: hkinni Time: 17/10/2015 23:17

Geoff, Martin, I am just lucky to meet these low-speed flying swiflets. Happy to know more about the swiflet from you. Thank you.

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