Marsh or Reed Warbler - Taken 9 October, Boca do Rio, Portugal (1 Viewer)

[ndsutcliffe]

I should point out that I am re-posting these photos to try and get a few more views on the ID. The reason is that I strongly suspect that this is a Marsh Warbler, however, Reed Warblers are much more common in the area. However I want more certainty as there doesn't appear to be a positive ID of a Marsh Warbler in Portugal (that I can find). So if it's Marsh, it is certainly a rare sighting.
My reasons for suspecting Marsh are :-

Pale eye ring which is similar coloured to the supercilium, whereas I would expect Reed to have a paler supercilium.
Olive tinged back and absence of rufous colour of Reed Warbler particularly on the rump
Off white yellowish underparts, perhaps paler than the buff of a Reed Warbler.
Pale bill with dark ridge, and shorter bill than Reed Warblers ?
Long Primaries
Squarish tail, darker than the body
A more rounded head, rather than flatter shape of Reed warbler.

I am not suggesting these are diagnostic, but at least evidential.

I should also say that I have never seen a Marsh Warbler before, so this is based largely on desk research, not personal experience.

I accept that Reed and Marsh are difficult to separate, but even if you're not sure, your opinion would be appreciated.

Finally to KenM and Harrybongo, who have previously expressed an opinion - I am not questioning your view (indeed I agree with you) but am merely trying to solicit more opinions, because this feels like it would be a rare sighting.

 

[Butty]

Not good etiquette to re-post. It's far more helpful to readers, and more respectful to past contributors, to add any additional points to your original:
Thread 'Algarve Warbler' Algarve Warbler
That will still bump it to the top of the pile and encourage people to take a second look.

 

[kuzeycem]

Hello,
Pale eye ring which is similar coloured to the supercilium, whereas I would expect Reed to have a paler supercilium.
Not true, Reed usually shows more prominent eye-ring, giving it a "googled" look whereas Marsh usually has eye ring and supercilium of equal prominence
Olive tinged back and absence of rufous colour of Reed Warbler particularly on the rump
This bird seems to be an adult (see worn tips to remiges and rectrices), which in autumn are more worn and have duller colors compared to juveniles in autumn or adults in spring. You can nevertheless see a slightly warmer rump in e.g. IMG 8789 (2).
Off white yellowish underparts, perhaps paler than the buff of a Reed Warbler.
See above.
Pale bill with dark ridge, and shorter bill than Reed Warblers ?
Bill colours not really relevant to species ID. Bill maybe does look a bit deeper based than most Reed but certainly nothing really unusual.
Long Primaries
Reed: %70-100, Marsh: close to %100. A bit on the longer side, but again within variation.
Squarish tail, darker than the body
Not relevant to ID (unless you have a source that says otherwise?)
A more rounded head, rather than flatter shape of Reed warbler.
Despite this bird having raised crown feathers, which would give it a more rounded crown than normal, this bird still has a rather flat forehead, with the head peaking behind eye - IMG 8783 (2) shows this well.

Also against Marsh Warbler - thin, greyish legs (both species tend to show yellowish feet/soles), warm brown colourations in forecrown and mantle (Marsh, especially such a worn one, wouldn't show such warm colouration, would be mostly greyish), rufous tones to the edges of secondaries, rather plain looking tertials, with the longest tertials not exceeding the length of secondaries (although admittedly a worn bird might not adhere to this, however I don't believe the tertial tips of this bird are worn enough to 'shorten' them).

BTW, in case my age determination is wrong (could be, iris is kinda dark?), 1stW Marsh still wouldn't show such warm brown colours to mantle and crown (they usually tend to have pale, straw-coloured upperparts, though a minority can show a slightly warmer rump), and the anatomical differences would still hold.

 

[ndsutcliffe]

Not good etiquette to re-post. It's far more helpful to readers, and more respectful to past contributors, to add any additional points to your original:
Thread 'Algarve Warbler' Algarve Warbler
That will still bump it to the top of the pile and encourage people to take a second look.

Happy to accept there may be a better way to do it, but etiquette? Really?

Just an amateur twitcher seeking help 🙂

 

[ndsutcliffe]

Hello,
Pale eye ring which is similar coloured to the supercilium, whereas I would expect Reed to have a paler supercilium.
Not true, Reed usually shows more prominent eye-ring, giving it a "googled" look whereas Marsh usually has eye ring and supercilium of equal prominence
Olive tinged back and absence of rufous colour of Reed Warbler particularly on the rump
This bird seems to be an adult (see worn tips to remiges and rectrices), which in autumn are more worn and have duller colors compared to juveniles in autumn or adults in spring. You can nevertheless see a slightly warmer rump in e.g. IMG 8789 (2).
Off white yellowish underparts, perhaps paler than the buff of a Reed Warbler.
See above.
Pale bill with dark ridge, and shorter bill than Reed Warblers ?
Bill colours not really relevant to species ID. Bill maybe does look a bit deeper based than most Reed but certainly nothing really unusual.
Long Primaries
Reed: %70-100, Marsh: close to %100. A bit on the longer side, but again within variation.
Squarish tail, darker than the body
Not relevant to ID (unless you have a source that says otherwise?)
A more rounded head, rather than flatter shape of Reed warbler.
Despite this bird having raised crown feathers, which would give it a more rounded crown than normal, this bird still has a rather flat forehead, with the head peaking behind eye - IMG 8783 (2) shows this well.

Also against Marsh Warbler - thin, greyish legs (both species tend to show yellowish feet/soles), warm brown colourations in forecrown and mantle (Marsh, especially such a worn one, wouldn't show such warm colouration, would be mostly greyish), rufous tones to the edges of secondaries, rather plain looking tertials, with the longest tertials not exceeding the length of secondaries (although admittedly a worn bird might not adhere to this, however I don't believe the tertial tips of this bird are worn enough to 'shorten' them).

BTW, in case my age determination is wrong (could be, iris is kinda dark?), 1stW Marsh still wouldn't show such warm brown colours to mantle and crown (they usually tend to have pale, straw-coloured upperparts, though a minority can show a slightly warmer rump), and the anatomical differences would still hold.

Thanks, this is really useful and I appreciate the detailed feedback.

 

[KenM]

Happy to accept there may be a better way to do it, but etiquette? Really?

Just an amateur twitcher seeking help 🙂

Quite right nds.👍

 

[KenM]

Just to show you how variable Reed Warblers can be NDS, here’s an overwintering one from 2014, this was on the forum and could not be ascribed to any particular race at the time.😮

 

[ndsutcliffe]

Thanks KenM - I'm now 100% certain that I've got a Marshy looking Reed Warbler or a Reedy looking Marsh Warbler, but on the basis that Reed are common there - I guess that's the call. At the same time it leaves me wondering whether Marsh are overlooked in Portugal for that very reason. Going back to my very first post - I've seen lots of Reed Warblers there, and this one somehow seemed different.

But anyway, thanks to all - I certainly know a lot more now than I did before

 

[Brian J Small]

ML119039671 - Marsh Warbler - Macaulay Library

Macaulay Library ML119039671; © Yann Kolbeinsson; Austurland, Iceland

macaulaylibrary.org

ML183931081 - Marsh Warbler - Macaulay Library

Macaulay Library ML183931081; © Ray Scally; East Riding of Yorkshire, England, United Kingdom

macaulaylibrary.org

The two links here show October MW. Note the longest tertial that extends slightly beyond the secondaries. These are in addition those already pointed out by Kuzeycem as features contra MW and pro RW

 

[ndsutcliffe]

ML119039671 - Marsh Warbler - Macaulay Library

Macaulay Library ML119039671; © Yann Kolbeinsson; Austurland, Iceland

macaulaylibrary.org

ML183931081 - Marsh Warbler - Macaulay Library

Macaulay Library ML183931081; © Ray Scally; East Riding of Yorkshire, England, United Kingdom

macaulaylibrary.org

The two links here show October MW. Note the longest tertial that extends slightly beyond the secondaries. These are in addition those already pointed out by Kuzeycem as features contra MW and pro RW

Thanks Brian. The pendulum swings further towards Marshy looking Reed warbler!

 

[jogresh]

In terms of how frequent Marsh are in reality, it's useful to look at data from some of the ringing programmes over the years in southern Portugal. Quite a lot of ringing has been done over the last 40 years or so, and from what i understand, Marsh Warbler is indeed extremely rare. This is presumed to be due to its migration route, a similar reason why Lesser Whitethroat, Red Backed Shrike etc are also very rare.

 

[kuzeycem]

ML119039671 - Marsh Warbler - Macaulay Library

Macaulay Library ML119039671; © Yann Kolbeinsson; Austurland, Iceland

macaulaylibrary.org

ML183931081 - Marsh Warbler - Macaulay Library

Macaulay Library ML183931081; © Ray Scally; East Riding of Yorkshire, England, United Kingdom

macaulaylibrary.org

The two links here show October MW. Note the longest tertial that extends slightly beyond the secondaries. These are in addition those already pointed out by Kuzeycem as features contra MW and pro RW

Hi Brian, just wondering how you'd age this bird? Adult or unusually worn 1cy?