Marsh Warbler at Spurn this Autumn

and the Caspian Reed/Blyth’s Reed/Reed Warbler ID process

On 9th October 2015 (earlier this month) Jeff Clarke leading a small and keen group of birders came across this warbler at Spurn. An acrocephalus (pointy head) warbler. Autumn ‘acros’ are notoriously tricky. The few I have seen at Flamborough this autumn, were all identifiable as Reed Warblers very quickly. Usually the plumage tones combined with ESPECIALLY the face pattern pointed the way.

‘acrocephalus’  roughly translates peak or pointy-headed. Some people think you need a pointy head to identify these little brown jobs. We covered 4 acrocephaplus warbler in Challenge Series: AUTUMN. They were Reed, Marsh, Blyth’s Reed and Caspian Reed Warbler. One of the questions once October comes around is that of vagrant Caspian Reed Warblers. Birds like this one flag up the challenge! They have reached Britain before!

Ageing

Nearly/all/all the birds we see in Britain are young birds in fresh plumage. The adult shave long since migrated. If we were to see an adult acrocepaphalus warbler it would look worn, moulting and weird/scary/ like a rare thing.

That Head Pattern

That head pattern with such a large open area in front off the eye is scary! It is very similar to some Caspian Reeds I have seen. It’s also very reminiscent of some Blyth’s Reeds. Its is also good for Marsh Warbler. Sheesh! Not really like a Reed Warbler at least so should draw the observer eye! I would be very exited to find a face like this.

Colours and Contrasts

Jeff Clarke describes the bird:

“The underparts were noticeably pale on this bird and in fact that is how we first picked it up in the hedge (at first glance I did wonder if it was a Hippo). Pale creamy buff is probably the best description of the underparts, slightly paler on the throat and no obvious darker wash on the flanks. Never got to see the leg colour properly, other than quite pale and couldn’t see the talon colour. The rump was definitely not rusty rump, but rather the colours were a  light olive-brown rump”

The tones and rump colour rule out western Reed (again). the long primary primary projection with striking pale tips, do point towards Marsh. On the upperparts the  Reeds I encountered were pretty plain- indeed with uppeparts/ primary zone that look like more like Blyth’s Reed. So this is a long-winded way of exploring best fit for Marsh Warbler, on head pattern, plumage tones above and below and the primary zone. Have a wee study of the pics 🙂

Well done Jeff and team for excellent find and ID process for us to learn from. Great experience for group birding… and of course it was at SPURN. Special thanks to Ben Miles for getting such informative photos. Great job! All photos below by Ben Miles

Spurn Warbler 1 Spurn Warbler 3Spurn Warbler 2

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