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Clamorous Reed Warbler or Oriental Reed Warbler? (1 Viewer)


Wei Qian
This photo was the Reed Warbler I saw in Chengdu city, southwest China, Oct 6th 2006. Can anybody help me identify which it is? or tell me the differences between Clamorous Reed Warbler(Acrocephalus stentoreus) and Oriental Reed Warbler(Acrocephalus orientalis).

Many thanks :)


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Well-known member
Hello there in China

Oriental Reed Warbler is between A.arundinaceus, orientalis and stenerous generally the least warm coloured bird. It mostly lacks the rufous tone to the upperparts and is browinsh olive-grey. Only when fresh, dark rufous above.The bird has often a streaked throat.Tips to the outer tailfeathers well defined and white.


Clamarous Reed finds in the mainland of Asia near Chengdu its most easterly distribution.(but again Indonesia and the Philippines)

Supposedly the short primary projection and the strong overall rufous colouration will lead us to Clamarous Reed. The bill is a bit hard to judge but seems long.


Well-known member
I think this is a bit tricky, and might come down on Oriental Reed Warbler. Primary projection is not that much greater in Oriental Reed, and is hard to judge from this angle. I think the tertials may be too dark centered to be Clamorous, and the supercillium fits Oriental Reed better to, seemingly extending beyond the eye. Check out:


(make sure the whole address is in your address bar).

I'm prepared to be wrong on this though!

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Well-known member
This bird seems to be quite fresh plumage, eg. whitish primary tips.

The colour of the lower mandible fits maybe better to Oriental RW, therefore Clamorous RW has always dark tip in the lower mandible ( about 1/3 ~ 1/4) as in Great RW. According to the few photos, Oriental RW can be also sometimes some dark in the lower mandible, but not so extensively. I also think that dark colour in the lower mandible is more typical for Clamorous.

Supercilium continues less distinctly beyond the eye in both species, so probably it's quite depatable character. But probably it's still stronger beyond the eye in Oriental in most cases than Clamorous.

This bird has 5 or 6 primary tips beyond the tertials, so it's very similar in both species in fresh plumage.

Clamorous Reed in the follow link is quite interesting,... http://orientalbirdimages.org/images/data/warbler1.jpg

Now I'd say it's more Oriental, but study continue ...

Would you kindly attach bigger copy on that photo or another pic in this thread?
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Well-known member
I really have great troubles in making this bird into one of the big Acrocephalus :egghead:
Bill seems not that strong and not that long and tail a bit short.
I would not exclude a smaller Acrocephalus so quickly but I'm wrong very probably. :brains:

Do you have other pictures metroplex ?
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amayae Clamorous and orientalis Oriental Reed belong to the most difficult subspecies between the two and those are the ones which occur in Southern China.
Some intergradation is suggested in literature.



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You will find few pics on Basra Reed Warbler (Acrocephalus griseldis) in the follow links, which is appr. same size as Clamorous (A. stentoreus)or Oriental Reed Warbler (A. orientalis). It does not look bigger Acro in many views...
It's sometimes difficult to realize and differ clearly the bigger Acros from the smaller Acros based on size in the pics.


Though this view angle is an extra difficulty in Metroplex's photo, but the bird looks quite "able-bodied" Acro. But that impression can be also illusion because of angle.

Only smaller Acro, which came to my mind and which can remind slightly this bird, is Blyth's Reed, but e.g. the colour of upperparts looks too dark and contrast between mantle and wings+tail is quite strong. Metroplex, what smaller Acro species you meet in the area?

This bird has a darkish loral area, but not darkish eye-stripe, which lead me to think that at least it's not Clamorous A. stentoreus. As far as I know, eye-stripe can lack or be weak in Oriental A. orientalis.

Bigger Acros have also relative short and less rounded tail. The shape of bill have quite long, more low-pitched in proportion to the lenght and looks quite dull in bigger Acros. Unfortunately the shape of bill does not show very clearly in Metroplex's pic!

Concerning to primary projection, it's very short in A. orientalis(~5-6 pf tips visible) and A. stentoreus (~5-7 pf tips visible), usually less than half of the lenght of tertials. That's very similar also in Blyth's Reed.
The length of pp in Great Reed Warbler A. arundinaceus is almost same or even longer than the lenght of tertials (in addition to 7-8 pf tips visible)


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Bigger Acros (Oriental?) from Japan


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Th_SQ said:
Basra has huge primary projection ! This bird has very short wings, hardly reaching upper-tail coverts ....
Prim proj looks indeed long in the 2nd pic. According to Svensson, A. orientalis wing 77-91mm, A.griseldis 78-88 mm, A.stentoreus ?, A.scirpaceus 62-73mm....


Well-known member
hannu said:
Prim proj looks indeed long in the 2nd pic. According to Svensson, A. orientalis wing 77-91mm, A.griseldis 78-88 mm, A.stentoreus ?, A.scirpaceus 62-73mm....

Wing length is not primary projection ...


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Th_SQ said:
Wing length is not primary projection ...

But you refered to bird's short wings, so the difference in wing length between these species is sometimes quite difficult to realize...


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To be informative on occurence of smaller Acro's:

Blyth's Reed, Blunt-winged, Black-browed Reed and Manchurian Reed Warbler all may have a migratory occurence in Chengdu and Paddyfield Warbler may touch the area as a winter bird.


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Exactly Hannu! and thanks for the linking.

For these both subspecies of Oriental Reed and Clamorous Reed, a fresh plumage would show in the middle of October. They both just finished their moult.
Even so, I find the primary projection of 5 extending feathers and the colour for both upperparts and underparts not convincing for the former.
For the headpattern I am divided, perhaps the complex of features in front of the eye may apply better to Oriental, but the super only shows 1 tiny litle streak pale behind the eye which is not so good for a typical one but rather better for Clamorous.

Oriental Reed shows a more pink colour to the bill than Clamorous.


Well-known member
Th_SQ said:
Thanks gerdwichers8 for the list. Ok, it may not be a small Acros but it's interesting that Paddyfield is possible ....

Hannu, do you really see anything in common between the bird and these pictures of Clamourous ?????

I don't understand, what is your purpose in your question???? :h?:
Both are Acro ? ;)
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