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Subject: Red-Backed Shrike [Print This Page]

Author: wilsondring    Time: 1/10/2013 22:02     Subject: Red-Backed Shrike

LV 01/10/2013

[ Last edited by wilsondring at 2/10/2013 09:29 ]

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http://www.hkbws.org.hk/BBS/attachment.php?aid=15744



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Author: gary    Time: 1/10/2013 22:41

It is a brown shrike.
Author: wilsondring    Time: 1/10/2013 22:58

Quote:
Original posted by gary at 1/10/2013 22:41
It is a brown shrike.
I think we are both wrong .. it may well be the same Red-Backed Shrike which Benjiman has just posted ..
Author: wgeoff    Time: 2/10/2013 08:23

Yes, I think this is the same bird as Benjiman's, I have seen other photos from him.

I think it is a juvenile Red-backed Shrike, from the barring on the head and back, the pale face mask and the square-ended tail.
But I'm no expert.
Author: wilsondring    Time: 2/10/2013 09:28

Quote:
Original posted by wgeoff at 2/10/2013 08:23
Yes, I think this is the same bird as Benjiman's, I have seen other photos from him.

I think it is a juvenile Red-backed Shrike, from the barring on the head and back, the pale face mask and the squa ...
many thanks .. more of an expert than most of us .. thanks again!
Author: mchristine    Time: 2/10/2013 10:40

I would much incline to support Gary's view that it is NOT a Red-backed Shrike.  According to the distribution map of Red-backed Shrike published by Birdlife, it is an European bird with declining population.  According to the information from "A Checklist on the Classification and Distribution of the Birds of China" (Chief Editor ZHENG Guangmei), Red-backed Shrike is much restricted to North Xinjiang only.

From the distribution perspective, the "suspected Red-backed Shrike" I saw in Long Yuen yesterday was unlikely to be a real Red-backed Shrike.  When I saw the bird, I would say that it mostly likely was a juvenile Brown Shrike.   

It would be good to seek expert advice from European and Xinjiang birders.

[ Last edited by mchristine at 2/10/2013 10:43 ]
Author: HKBWS Vicky    Time: 2/10/2013 10:54

Red-backed Shrike is recorded in Long Valley last year but definitely this is not the same individual.
Very good record!
Author: lpaul    Time: 2/10/2013 11:13

Juvenile/first-winter Red-backed Shrike based on very warm upperparts, white ground colour to the underparts, long primary projection, rather square tail and white fringe to the outer tail feathers.
Author: wilsondring    Time: 2/10/2013 11:35

thank you for all the inputs .. if you need any more photos of different views, please let me know, cheers
Author: HKBWS Ivan    Time: 2/10/2013 13:24

More information for ID Brown Shrike and Red-backed Shrike from TaiWan Birder forum

http://nc.kl.edu.tw/bbs/showpost.php?p=437424&postcount=19
Author: mchristine    Time: 2/10/2013 13:29

Quote:
Original posted by lpaul at 2/10/2013 11:13
Juvenile/first-winter Red-backed Shrike based on very warm upperparts, white ground colour to the underparts, long primary projection, rather square tail and white fringe to the outer tail feathers.
It should become a ground breaking finding if it is all confirmed that it is a Red-backed Shrike, juvenile in particular.  All sources I came across consistently stated that Red-backed Shrike was a migrating bird found scarcely in Europe,  Russia, Africa, Northern China yet never mentioning Hong Kong as far as I am aware of.  Shouldn't these sources be updated?
Author: ajohn    Time: 2/10/2013 14:25

Christine, your books are correct that Red-backed Shrike breeds across Europe and only as far east as Xinjiang. It is a declining species in much of the range, but is still numerous across most of the range. The species is a long-distance migrant, wintering in Africa.

Like many birds, some individuals occasionally go 'the wrong way' and turn up in unexpected places. This is the case with this bird - although Red-backed shrike is not normally seen in HK, occasional individuals do turn up. I think this is the 5th to be recorded in HK so far. There are also records from other parts of East Asia (Taiwan, Korea, Japan).

Most birds turning up out of range in this way will be juveniles/first winter, because the adults have already made the migration and will know which way to go, whereas the young birds are making their first migration and are more likely to make a mistake.
Author: mchristine    Time: 2/10/2013 15:03

Quote:
Original posted by ajohn at 2/10/2013 14:25
Christine, your books are correct that Red-backed Shrike breeds across Europe and only as far east as Xinjiang. It is a declining species in much of the range, but is still numerous across most of the ...
Dear AJohn,

Thank you for your sharing.  Once again, all these bird books and webpages should be advised to be updated if Red-backed Shrike were consistently found in Taiwan, HKG, Japan............
Author: wilsondring    Time: 2/10/2013 15:19

Quote:
Original posted by mchristine at 2/10/2013 15:03

Dear AJohn,

Thank you for your sharing.  Once again, all these bird books and webpages should be advised to be updated if Red-backed Shrike were consistently found in Taiwan, HKG, Japan............ ...
If only the 5th record equates to "consistently found" then yes, maybe they should informed of and updated accordingly...
Author: tomatofamily    Time: 2/10/2013 16:41

I also saw this same bird when I arrived LV this morning (2/10/2013) at around 8 am.  Three birdwatchers have been there taking pictures of it.  I walked close to join them and took my photos too.  The bird was so "generous" to let us take as many photos as possible.  It was nice to watch this bird standing gracely on the wire and occasionally flew to the wet field and had a drink or caught a grasshopper.
Author: thinfor    Time: 2/10/2013 22:02

Quote:
Original posted by mchristine at 2/10/2013 15:03

Dear AJohn,

Thank you for your sharing.  Once again, all these bird books and webpages should be advised to be updated if Red-backed Shrike were consistently found in Taiwan, HKG, Japan............ ...
For classifying the tendency of the bird to be seen in a place or a country, there is a status called 'vagrant'.  We don't know why it appears there anyhow, but it does, and why not, it has wings.

I am not sure how technical a bird is said to be vagrant but a bird said to be vagrant can appear every year.  That may also be likely to happen.  HKBWS has been keeping the records well, I'm sure, for this bird as well as all other bird species.

Though books and webpages may be too lazy to be updated, some sources are still quite remarkable.  I've searched HBW online to help myself to identify this shrike.  One of the behavioral difference between brown and red-backed shrike may be pinpointed somehow and I quote here:

Rather small shrike with fairly short wings and longish tail; when excited, indulges in tail movement in form of loose flick or curving swing, accompanied by partial spreading of tail.

The above can be seen in Descriptive Notes for Red-backed Shrike but not in Brown Shrike.  Of course, the above should not be a diagnostic point for identifying red-backed shrike but I'm sure I did see the tail movement of this bird in LV.  For me, it's one more point that fits it is a red-backed shrike (Again, this is not diagnostic, just a minor point).

HBW also gives the following information about the vagrant status of red-backed shrike:
Vagrant in: Algeria, Ascension Island, Azores, Cameroon, Canary Islands, Central African Republic, Faeroe Islands, Gibraltar, Iceland, Ivory Coast, Japan, Madeira Islands, Mongolia, Morocco, Niger, Nigeria, São Tomé and Principe, Seychelles, Socotra, South Korea, Svalbard Islands and Jan Mayen, Taiwan.

My humble comments:
As such, the bird's distribution seems hard to give us inclination on the identification of species.  Instead, we base on the physical features to identify the bird.  The question on the origin of the bird will be another issue.

[ Last edited by thinfor at 2/10/2013 22:06 ]
Author: gary    Time: 2/10/2013 22:51

If the above is Red-backed Shrike, the first record for the species in HK should be this:
http://www.hkbws.org.hk/BBS/view ... &extra=page%3D7

Actually I recall we have encountered a few of them in this forum which we ID as Brown Shrike.

Gary
Author: JamesLambo    Time: 2/10/2013 23:33

If the above is Red-backed Shrike, the first record for the species in HK should be this:
http://www.hkbws.org.hk/BBS/view ... &extra=page%3D7

Actually, on first look these birds seem similar, but I think the 2006 Po Toi bird is a juvenile Brown Shrike.

The ear coverts are dark grey (not red-brown).
The tail is slightly forked (not straight)
The primary projection is shorter, less than half the tail length (the RB Shrike is much longer, half the tail length)

According to Svensson (2009), immature RB Shrikes and immature Brown Shrikes "strongly resemble" one another.

James
Author: wgeoff    Time: 3/10/2013 06:49

I think this is my fault for suggesting the barring on the head and back was distinctive of Red-backed, which it clearly is not. As I say, I'm no expert.

Paul Leader has listed the key identification features above as

'very warm upperparts, white ground colour to the underparts, long primary projection, rather square tail and white fringe to the outer tail feathers'

but I think the pale face mask is also distinctive, at least between Brown and Red-backed.
Another source for the differences is pages 258 to 260 of the 2007-08 HKBR, the first HK Record of Red-backed Shrike, which includes a description in English and in Chinese and is given here

"This bird was easily aged as a first-winter due to the retained juvenile greater coverts and tertials. Identification was less straightforward but was based on a combination of rather rufous tones above (strongest on the uppertail coverts), a long primary projection, whitish underparts, more square (i.e. less rounded tail), rather slender bill and poorly-defined mask. In combination these eliminate other shrike species, but especially Brown Shrike L. cristatus, the most likely confusion species. Red-backed Shrike breeds from Europe west to Xinjiang Province, China. It is a long distance migrant and has been recorded as a vagrant to Japan, South Korea and Taiwan. Given the condition of this individual and migratory behaviour of the species, the Records Committee readily accepted this to Category I of the Hong Kong List.

辨認這鳥為首次渡冬鳥很容易,是因為牠保留了幼鳥的大覆羽和三級飛羽。要辨認這鳥種就較為因難,不過根據上述部分略帶紅色(在尾上覆羽最為明顯)、修長的外型、白色的下體、較方型的尾部(即尾部形狀沒有那麼圓)、稍為纖細的喙部,以及不太明顯的眼紋等特徵可得出結論。綜合這些特徵,便可以排除屬其他伯勞的可能性,尤其是最有機會混淆的紅尾伯勞 L. cristatus。紅背伯勞的繁殖地遍及西歐至中國新疆。這鳥會作長途遷徙,曾在日本、南韓和台灣有紀錄,並被列作迷鳥。基於這鳥的情況以及這鳥種的遷徙行為,紀錄委員會十分樂意將這鳥種加入香港鳥類名錄第I類。"

I think it is quite possible some juvenile/first winter Red-backed Shrikes have been overlooked in the past, since we've now had five records in five years.

[ Last edited by wgeoff at 3/10/2013 07:44 ]
Author: lpaul    Time: 3/10/2013 10:25

Quote:
Original posted by gary at 2/10/2013 22:51
If the above is Red-backed Shrike, the first record for the species in HK should be this:
http://www.hkbws.org.hk/BBS/view ... &extra=page%3D7

Actually I recall we have encountered a few ...
No, this is a Brown Shrike with extensive retained juvenile plumage.
Author: mchristine    Time: 4/10/2013 12:41

Would like to share with you all an interesting and informative article in relation to the above differentiation

http://www.dutchbirding.nl/content/journal/pdf/2000-6.pdf
Author: handrew    Time: 4/10/2013 14:48

Quote:
Original posted by mchristine at 4/10/2013 12:41
Would like to share with you all an interesting and informative article in relation to the above differentiation

http://www.dutchbirding.nl/content/journal/pdf/2000-6.pdf
Interesting article - I noted on collurio it says: The undertail is always greyish and the outermost rectrices show a whitish
fringe. These features, together with the distinctive long-winged and short-tailed structure, are diagnostic. Here is an image I took that appears to show the grey undertail.

Image Attachment: RBSJuv undertail.jpg (4/10/2013 14:48, 152.54 KB) / Download count 167
http://www.hkbws.org.hk/BBS/attachment.php?aid=15776






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