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        Discussion Area 討論區 >> Bird Identification 鳥類辨識 >>  Japanese Bush Warbler in Japan
        
(Message started by: HF_Cheung on Jun 20^th, 2006, 9:11pm)

Title: Japanese Bush Warbler in Japan
Post by HF_Cheung on Jun 20^th, 2006, 9:11pm

http://www.geocities.com/aphfcheung/DSCN9408.jpg
Following up the discussion of Manchurian Bush Warbler versus Japanese Bush Warbler, Mike Kilburn has kindly supplied this photo. This is Japanese Bush Warbler taken in Hokkaido by Matsui-san in October. This is the subspecies of Japanese Bush Warbler that occurs in Japan and Taiwan. The other subspecies breed in NE China and migrate through HK (also Taiwan) in Autumn, and some winter in HK. There is a very significant difference in the colour of the crown between the bird in this photo and the bird seen in HK.

HF Cheung

Title: Re: Japanese Bush Warbler in Japan
Post by HF_Cheung on Jun 22^nd, 2006, 9:53pm

http://www.geocities.com/aphfcheung/Dscn2793P.jpg
For comparision, please see this "Japanese" Bush Warbler trapped in Mai Po in winter.

Mike Leven sent me the following description from Vaurie (The Birds of the Palearctic Fauna) which has a description of the differences between canturians and other forms, as follows:

"(canturians) differs from both borealis and cantans by being more richly coloured, strongly rufous above, under parts darker buff than in borealis, not washed with olive as in cantans; large, wing longer than in cantans but slightly shorter than in borealis, measuring 73 - 76 in ten males, feet much stronger than in cantans, similar to those of borealis"

I have checked the ringing data in my hand, and come up with the following statistics. The data shows that most of our birds have wing length in the range 72-77, which a few exceptions that may refer to borealis.

wing
length occurrence

80 3
79 3
78 4
77 12
76 28
75 24
74 27
73 12
72 12
71 4
70 0

HF Cheung

Title: Re: Japanese Bush Warbler in Japan
Post by geoff_welch on Jun 28^th, 2006, 8:26am

I have just returned from a short trip to the central mountains of Hokkaido, where I heard quite commonly what I believe was Japanese Bush Warbler singing. I say believe because I never managed to see the bird, but have identified the calls from the website midopika.cool.ne.jp/songs_e which has a good number of Japanese bird songs.

There were two quite different songs/calls. The first started with a whistle, similar to our Brownish-flanked Bush Warbler, followed by a short warble which seemed to vary from bird to bird. This song appears in the 'song' section of the above website for 'Bush Warbler'.

The second call, heard a few times, started with a fast trill which I noted as 'heechoo' repeated fast at first, gradually slowing down to a slow double note but the whole thing sometimes lasting over 30 seconds. This appears as 'alarming 2' on the above website.

I wonder if these songs/calls, presumably diphone, differ from borealis or canturians?

Title: Re: Japanese Bush Warbler in Japan
Post by HF_Cheung on Jun 28^th, 2006, 9:53pm

Dear Geoff,

I looked up the songs in the webpage that you quoted. I think the author have mixed up the songs and calls of Strong-footed Bush Warbler (Mountain Bush Warbler) with Japanese Bush Warbler. Both species are there.

HF Cheung

Title: Re: Japanese Bush Warbler in Japan
Post by geoff_welch on Jun 29^th, 2006, 7:12am

Thanks HF.
But I am left with a puzzle. If the bird I heard making both calls was not Japanese Bush Warbler diphone, what was it? I don't think it can be Brownish-flanked (Mountain) Bush Warbler which does not occur in Japan.
Any ideas?