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Subject: Asian and Northern House Martins [Print This Page]

Author: John Holmes Time: 16/11/2016 10:51 Subject: Asian and Northern House Martins

10th Nov 2016 Tai Sang Wai 7D2 + 500mm f4

Image Attachment: [ASIAN House Martin] AsianHM161110_jjh.jpg (16/11/2016 10:51, 60.74 KB) / Download count 457
http://hkbws.org.hk/BBS/attachment.php?aid=27961

Image Attachment: [NORTHERN House Martin] NorthernHM161110_jjh.jpg (16/11/2016 10:51, 43.54 KB) / Download count 476
http://hkbws.org.hk/BBS/attachment.php?aid=27962

Author: subbuteo Time: 16/11/2016 18:36

Thanks John- good to have a comparison like that! It looks like Northern has a deeper fork in the tail and a more extensive, cleaner white rump- any thing else to look for?

Dylan

Author: lpaul Time: 17/11/2016 17:01

John, do you have photos of the underparts of both you can add?

Author: John Holmes Time: 18/11/2016 07:39

Hi Dylan and Paul

- here are some shots of the underparts - only one of the Northern House Martin, then four of what I think is Asian.

Asian is more compact, and, as you know, often is darker on the flanks and rest of the body, but this is a variable feature. (and according to "The Avifauna of HK" there are two possible AHM races to occur here..!)

[ Last edited by John Holmes at 18/11/2016 07:42 ]

Image Attachment: [Northern House Martin] N161110_jjh_13-01.jpg (18/11/2016 07:39, 40.39 KB) / Download count 445
http://hkbws.org.hk/BBS/attachment.php?aid=27976

Image Attachment: [Asian House Martin] A161110_jjh_02-01.jpg (18/11/2016 07:39, 39.81 KB) / Download count 468
http://hkbws.org.hk/BBS/attachment.php?aid=27977

Image Attachment: [Asian House Martin] A161110_jjh_05-01.jpg (18/11/2016 07:39, 58.54 KB) / Download count 469
http://hkbws.org.hk/BBS/attachment.php?aid=27978

Image Attachment: [Asian House Martin] A161110_jjh_11-01.jpg (18/11/2016 07:39, 44.76 KB) / Download count 478
http://hkbws.org.hk/BBS/attachment.php?aid=27979

Image Attachment: [Asian House Martin] A161110_jjh_18-01.jpg (18/11/2016 07:39, 70.66 KB) / Download count 467
http://hkbws.org.hk/BBS/attachment.php?aid=27980

Author: lpaul Time: 23/11/2016 10:00

John,

I think your photos show both taxa of Asian House Martin that occur in HK.

Note that all your birds are first-winter birds based on the white tip to the tetials.

The two Asian House Martin taxa that occur (nigrimentalis from se China and Taiwan) and nominate dasypus (ne China, Korea, eastern Russia)can generally be separated on size, structure and plumage. The former is much more sullied below and on the rump and is smaller which a shorter more shallowly forked tail (as per the 2nd and 3rd images in your second post). Nominate dasypus is much cleaner below and on the rump, is larger and has a longer and more deeply forked tail (4th and 5th images).

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