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.
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Last edited by thinfor at 2/10/2013 22:06 ]
