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        Discussion Area 討論區 >> Bird Identification 鳥類辨識 >>  Probable Sand Martin at Mai Po today
        
(Message started by: Neil on Apr 4^th, 2006, 9:51pm)

Title: Probable Sand Martin at Mai Po today
Post by Neil on Apr 4^th, 2006, 9:51pm

Digiscoped this morning around the Mai Po fish ponds. Is it a Sand Martin? Neil.

Mai Po fish ponds,
Hong Kong,
China.
04/04/06

Olympus 7070wz and Swarovski STS80HD scope and 30x eyepiece.

http://www.pbase.com/neilfif11/image/58184985.jpg

Title: Re: Probable Sand Martin at Mai Po today
Post by Paul Leader on Apr 5^th, 2006, 9:00pm

No, this is almost certainly a fokhiensis sand martin, which is currently best treated as a subspecies of Pale Martin Riparia diluta, but may well a good species.

Based on an examination of skins at the British Museun recently, structure is the best feature with the wings obviously longer than the tail, and with a very shallow tail fork. Do you have any pictures of the underparts or in flight?

This is not currently on the Hong Kong list, but based on photographs (already on the bulletin board elsewhere) this has occured on at least two previous occassions.

I think that it has been much overlooked and that winter and early spring records relate to this taxon and that the main passage of 'Sand Martins' in late April and early May are really Sand Martin and not Pale Martin.

Where exactly was it? I shall have a look tomorrow morning.

Title: Re: Probable Sand Martin at Mai Po today
Post by Neil on Apr 6^th, 2006, 7:31am

Paul,
Thanks for your comments. I thought when nobody had replied for a couple of days that it must be too obvious. This is the only angle I managed to photograph of the bird unfortunatley and I only got 4 photos before it flew off.
It was on the low wires alongside the fish pond by the road into the Mai Po on the left by the road that leads to a few shacks. Neil.

Title: Re: Probable Sand Martin at Mai Po today
Post by ptarmigan on Apr 6^th, 2006, 1:18pm

Paul,
As you said "structure is the best feature with the wings obviously longer than the tail, and with a very shallow tail fork." do you mean that it's the best way to id the Riparia diluta fokienensis with Riparia riparia ijimae which both can be seen in eats and south China?
And how to id the fokienensis with tibetana both can be seen in Sichuan?
Thank you very much?

Title: Re: Probable Sand Martin at Mai Po today
Post by ptarmigan on Apr 6^th, 2006, 1:22pm

As to the R.r.forkiensis, you can find the relevant photo at the url below,which was photoed in Shanghai:
http://www.wwfchina.org/birdgallery/showpic.shtm?id=188

and as to the R.r.ijimae, you can find the relevant photo at the url below,which was photoed in Beijjing:
http://www.guanniao.com/bbs/UploadFile/2005-8/20058221957843.jpg

Title: Re: Probable Sand Martin at Mai Po today
Post by Paul Leader on Apr 13^th, 2006, 11:31am

ptarmigan,

sorry for not responding to your posting before.

Yes structure is the best way to separate fokiensis from ijimae, however, fokiensis sseems to occur in HK when moulting the primaries and tail so this needs to be taken into consideration.

Separation of fokiensis from tibetana relies on the pattern of the underparts; fokiensis has a well defined, neat and relatively dark breast band, whereas tibetana has a more diffuse and paler breast band. In pluamge terms fokiensis is more similar to ijimae than to tibetana, whereas the converse is true in terms of structure.

Hope this helps.

Title: Re: Probable Sand Martin at Mai Po today
Post by ptarmigan on Apr 14^th, 2006, 11:03am

thank you very much Paul!
And sorry for one more question:
Do you think we can id fokienensis and ijimae by the colour of the mantle and the breast band?
According to "Fuana Sinica Aves Vol.8"(Zheng Baolai et., Science Press,1985), ijimae has more dark mantle, and fokienensis has more neat, defined breast band.
Do you think these are the key points in id?
Thank you !

Ptarmigan