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        Discussion Area 討論區 >> Photo Gallery 相片分享 I >>  Slaty-backed Gull 灰背鷗 In-flight 飛行
        
(Message started by: Daniel CK Chan on Apr 24^th, 2004, 7:15am)

Title: Slaty-backed Gull 灰背鷗 In-flight 飛行
Post by Daniel CK Chan on Apr 24^th, 2004, 7:15am

167 Slaty-backed Gull 灰背鷗
Mai Po 米埔
20/4/2004
10D + 500 + 1.4x
http://kite.center.kl.edu.tw/vbb/attachment.php?s=&postid=116235
http://www.hkbws.org.hk/fileServer/PhotoG/danelckchan/daniel_ck_chan_003.jpg
http://kite.center.kl.edu.tw/vbb/attachment.php?s=&postid=116234
http://www.hkbws.org.hk/fileServer/PhotoG/danelckchan/daniel_ck_chan_004.jpg

A 1st winter one. Would you suggest the reasons of the worn-out feather. Thanks.

Title: Re: Vega Gull 紅腳銀鷗 In-flight 飛行
Post by KK Hui on Apr 24^th, 2004, 9:15am

Daniel,

I like both shots particularly the first one. Yes, wished its feathers were in a better shape! ;D ::) ;D

KK Hui ARPS
www.geocities.com/kkhui_001

Title: Re: Vega Gull 紅腳銀鷗 In-flight 飛行
Post by gjcarey on Apr 24^th, 2004, 2:30pm

Excellent shot Daniel.

It's actually a 1st year Slaty-backed Gull. The mantle is too dark and grey and the tail band can be seen to be very broad - almost the whole tail is uniform brown. The head is paler than the body and it is a rather bulky bird with broad-based wings and thick neck.

The feathers are so badly damaged because of the damage that exposure to the sun causes. This bird has probably been wintering further south, where the winter sun is even stronger than it is here. The sun causes feathers to fade and it also breaks them down. Paler feather areas are more susceptible to damage than darker; you can see this effect on this bird.

Slaty-backed Gulls seem particularly prone to this kind of damage, but that may be related to the fact that the vast bulk of the population winters quite far north in east Asia, mostly in Japan. There, the sun is far weaker and days much shorter; consequently, less damage is caused to feathers, and so the species has evolved without strong resistance.

Incidentally, I'm pretty sure this is the latest HK record of this species.

Well done!

Geoff

Title: Re: Slaty-backed Gull 灰背鷗 In-flight 飛行
Post by Daniel CK Chan on Apr 24^th, 2004, 6:55pm

Geoff,
Thanks for clarification and detailed information. I have difficulties to distinguish two species especially that they are quite similar in 1st winter.
Thanks again.
Regards
Daniel