Reed Warbler ID, Dali, Yunnan, China (1 Viewer)

[Barbets48]

Location: Dali Wetland Park, Yunnan China, in July

Multiple birds seen over the course of the day. Would appreciate help with these photos and sounds, as according to checklists from this location both Clamorous and Oriental Reed Warblers are present. Below are media from three different individual birds.

Bird #1: Photos 1-3 and the audio clip (MP3) are the same bird.
Bird #2: Photos 4-6 are a different bird. The video clip (MP4) is also this bird.
Bird #3: Photos 7-8 are a third bird.

There seems to be so much variability to plumage looking through each species' photos in eBird, so would appreciate any help for ID.

Mike

 

[mummymonkey]

Of the two species I only have experience of clamorous.
Just on the song, clamorous has a distinctive pattern it inserts into its song. Kind of like - "daw doh detch iss" with the emphasis on the 3rd syllable.
Sometimes just parts of that - "doh-detch-iss" or even just "detch-iss".
I think I can just about hear something like that in your recording.

 

[Grahame Walbridge]

1-3 Very poor quality of images makes for a difficult ID but, based on the profile shot (2), the bill looks particularly long and slender, combined with a very weak and narrow supercilium which is a better fit for Clamorous Reed which the song confirms IMO. The taxon amyae is thought to be resident at this (and other) locations in Yunnan; its range extends disjunctly to c, ne Sichuan and s Guizhou Provinces.
4-8 Look better for Oriental Reed based on combination of bill structure, strong supercilium and length of pp. Doubtful they are resident as Yunnan is well outside known breeding range which lies further NE.

Grahame

 

[andyb39]

I would tend to agree, Grahame - the first bird looks like Clamorous in image 2, the third bird like Oriental, especially with those white tips to the rectrices. The images of the second bird are a little ambiguous but the impression I get from the video clip is that it isn't a Clamorous - the bill looks too small and the wings slightly too long.

 

[Barbets48]

Thanks all for your help with this one! Much appreciate the ID tips. Will give me something to look for in the future as well.

 

[johnallcock]

Although I don't have much personal experience of Clamorous, I would say that all birds look like this rather than Oriental.

Bird 1 (photo 1-3) is very long billed, and the song recording is definitely better for Clamorous.
Bird 2 (photo 4-6) also looks like it has quite a long, slender bill to me, not as heavy as I would normally expect on Oriental, perhaps enhanced by the long, sloping forehead. Although the front of the supercilium is fairly prominent, it is pretty indistinct behind the eye. The wings don't look that long to me, maybe about 50% of tertial length on photo #5, and I'm a bit concerned that it looks like it may be moulting, which could affect apparent wing length.
Bird 3 (photo 7-8) the bill structure and head pattern are difficult to judge from the angle of the head, but the supercilium doesn't seem very prominent on photo 8. To me the wing looks short, especially considering that it is partly open, and the tail looks relatively long. I'm cautious about trying to interpret the pale tips to the tail, as the feathers will be worn at this time of year, and there is similar pale fringing around the wing and tail sides, which would suggest some degree of photo artefact.

I remember Clamorous being fairly common around Dali when I visited (in summer). I wouldn't expect Oriental to be in the area in July, as they should be on breeding grounds further north and east.

 

[Grahame Walbridge]

John is of course correct in that the balance of probability must be strongly in favour of Clamorous for all these birds. It is known to be resident at this location while Oriental would be well out of range at this time of year which I should have taken into account.

Images of amyae from Myanmar Oriental Bird Club Image Database : Clamorous Reed Warbler » Acrocephalus stentoreus and India
Oriental Bird Club Image Database : Clamorous Reed Warbler » Acrocephalus stentoreus illustrating variation in strength of fore-supercilium with, as John remarks, little or no extension beyond the eye, contra ORW. All the birds are likely well worn so late in the season and, on closer inspection, the second individual (4-6) may be moult as John alludes.

Looking again at birds 2 and 3, I would concur with John's assessment that pp would appear to be too short and tail too long for ORW.

Grahame