Folks, this from a very experienced RSPB ringer friend of mine:

’ The Meare Heath bird is fairly safely a sedge warbler. The head pattern is normal for sedge - autumn birds often show such pale/contrasting central crown stripes. The difference is that the forehead and the front of the supercilium (before the eye and towards the bill base) are a pale creamy colour. On aquatics, these areas are distinctly rusty; this is often the first thing you notice when you pull them out of mistnets. The loral stripe and lateral crown stripes at the front are also thin and very dark, emphasising the paleness of these stripes. An aquatic warbler would not show such a dark loral stripe.

I confess that I’ve only seen a small number of aquatics - all in the hand. You should be able to find other ringers who’ve handled more (they will be the older/more experienced ones, as aquatic numbers have been poor for a number of years now) - I’m sure that they will back up these comments. I can say that I have seen a lot of sedges in the field and in the hand that are as striking as this ... causing much unwarranted excitement.

...and a big thanks to Paul for sharing these very instructive photos in the first place - very much appreciated…

Andy

I’m not experienced with this species, having only ever seen two, but looking in various books including the Helm Guide to Bird ID by Vinicombe et.al. shouldn’t a juv Aq W show a pale lower mandible, pale lores and have pointed tail feathers - the central two protruding; also be bronze-tinged to the crown-stripe above the bill base at its widest, the crown-stripe then narrowing over the head. A juv Aq W doesn’t moult its flight feathers (wing & tail) until after mig to its wintering grds. Some juv Sedge W can show a fairly prominent pale central-crown stripe that widens from the bill base over the head, so not convinced that this isn’t just one of these?

Andy,

I could equally be wrong and the Lytchett bay bird is a classic fresh Autumn juvenile from what I’m told, I believe it has been confirmed by Lee Evans among others. Having never seen one and it being somewhat of a bogey bird of mine I’m hoping it is and is still present! It does look paler but the head on shot of the crown looks too strong for Sedge to me. I’m sure there will be some debate on this.

Hi Ryan.  Have seen the photos.  Here’s the recent Dorset bird for comparison:

https://mobile.twitter.com/ianballam/status/771010778237394944

I still question the Somerest ID at this stage but accept I could be wrong…!

Andy,

Looking good on this one, the observer has posted two very good photos on Twitter…..I’m sure there will be a few there looking for it tomorrow am! Sadly I can’t make it until the afternoon if it’s still around

Hi folks. Views on this ID…?  Are the lores and crown stripe pale enough for AW?  Happy to be shot down if the evidence is there…
Andy

1-Sep-2016
Per Paul @beardedtit68 on Twitter: A possible Aquatic Warbler reported, together with its photo, from Meare Heath Hide at 11:30 this morning.

Paul’s photos can be seen here
https://pbs.twimg.com/media/CrR1GytWEAAuDpG.jpg
https://pbs.twimg.com/media/CrSd_dxW8AAc3rY.jpg